4 handover

BSC Counters: HandoverMeasurement

DN9813636 © Nokia Corporation 1 (162)Issue 7-0 en Nokia Proprietary and Confidential

BSC Counters: Handover Measurement

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2 (162) © Nokia Corporation DN9813636Nokia Proprietary and Confidential Issue 7-0en

Contents

Contents 3

List of figures 4

Summary of changes 7

1 BSC Counters: Handover Measurement 9

2 Counters of Handover Measurement 17

3 Signalling charts of Handover Measurement 101



List of figures

Figure 1. Successful internal intra-cell TCH to TCH handover. 102

Figure 2. Successful internal inter-cell TCH to TCH handover. 103

Figure 3. Successful external TCH to TCH handover, source BSC. 105

Figure 4. Successful external TCH to TCH handover, target BSC. 106

Figure 5. Successful internal intra-cell SDCCH to SDCCH handover. 107

Figure 6. Successful internal inter-cell SDCCH to SDCCH handover. 108

Figure 7. Successful external SDCCH to SDCCH handover, source BSC. 110

Figure 8. Successful external SDCCH to SDCCH handover, target BSC. 111

Figure 9. Internal intra-cell directed retry including feature BSS6114: TCHassignment to the super-reuse TRX in IUO. 112

Figure 10. Internal inter-cell directed retry, including feature BSS6114 TCHassignment to the super-reuse TRX in IUO. 113

Figure 11. External directed retry, source BSC. 114

Figure 12. External directed retry, target BSC. 115

Figure 13. Unsuccessful internal intra-cell TCH to TCH handover due to a lack ofresources. 116

Figure 14. Unsuccessful internal inter-cell TCH to TCH handover due to a lack ofresources. 117

Figure 15. Unsuccessful external TCH to TCH handover due to a lack of resources,source BSC. 118

Figure 16. Unsuccessful external TCH to TCH handover due to a lack of resources,target BSC. 119

Figure 17. Unsuccessful internal intra-cell TCH to TCH handover because ahandover is not allowed at this phase of the call. 120

Figure 18. Unsuccessful internal inter-cell TCH to TCH handover because ahandover is not allowed at this phase of the call. 121

Figure 19. Unsuccessful external TCH to TCH handover because a handover is notallowed, source BSC. 122

Figure 20. Unsuccessful internal intra-cell TCH to TCH handover due to a failure inthe activation of a new channel. 123

Figure 21. Unsuccessful internal inter-cell TCH to TCH handover due to a failure inthe activation of a new channel. 124

Figure 22. Unsuccessful external TCH to TCH handover due to a failure in theactivation of a new channel, target BSC. 125


Figure 23. Unsuccessful internal intra-cell TCH to TCH handover due to losing theMS during handover. The GSM timer T3107 expires. 126

Figure 24. Unsuccessful internal inter-cell TCH to TCH handover due to losing theMS during handover. The GSM timer T3103 expires. 127

Figure 25. Unsuccessful internal intra-cell TCH to TCH handover due to MS returningto the old channel. 128

Figure 26. Unsuccessful internal inter-cell TCH to TCH handover due to MS returningto the old channel. 129

Figure 27. Unsuccessful external TCH to TCH handover due to MS returning to theold channel, source BSC. 130

Figure 28. Unsuccessful external TCH to TCH handover due to MS returning to theold channel, target BSC. 131

Figure 29. Unsuccessful internal intra-cell TCH to TCH handover due to call clearingduring handover. 132

Figure 30. Unsuccessful internal inter-cell TCH to TCH handover due to call clearingduring handover. 133

Figure 31. Unsuccessful external TCH to TCH handover due to call clearing duringhandover, source BSC. 134

Figure 32. Unsuccessful internal intra-cell TCH to TCH handover because no radioresources are available due to switch_crc_pool. 135

Figure 33. Unsuccessful internal inter-cell TCH to TCH handover because no radioresources are available due to switch_crc_pool. 136

Figure 34. Unsuccessful external TCH to TCH handover because no radio resourcesare available due to switch_crc_pool, target BSC. 137

Figure 35. Successful handover type reselection from an internal intra-cell TCH toTCH handover to an external handover due to switching the circuitpool. 138

Figure 36. Successful handover type reselection from an internal inter-cell TCH toTCH handover to an external handover due to switching the circuitpool. 139

Figure 37. Unsuccessful external TCH to TCH handover because the MSC rejectsthe handover due to various causes, source BSC. 140

Figure 38. Unsuccessful external TCH to TCH handover due to GSM timer T8 expiry,source BSC. 141

Figure 39. Unsuccessful external TCH to TCH handover due to adjacent cell error,source BSC. 142

Figure 40. Unsuccessful internal intra-cell TCH to TCH handover, caused by aninternal timer expiry in the BSC or a CONNECTION_FAILURE,ERROR_INDICATION, or ERROR_REPORT message coming to thetarget channel. 143



Figure 41. Unsuccessful internal inter-cell TCH to TCH handover due to a radio linkfailure during handover. 144

Figure 42. Unsuccessful internal inter-cell TCH to TCH handover caused by internaltimer expiry or a failure in the connection of a bi-directional speechpath. 145

Figure 43. Unsuccessful external TCH to TCH handover due to a radio link failureduring handover, source BSC. 146

Figure 44. Unsuccessful external TCH to TCH handover due to a radio link failureduring handover, target BSC. 147

Figure 45. Unsuccessful external TCH or TCH handover, source BSC. 148

Figure 46. Unsuccessful external TCH to TCH handover, target BSC. 149

Figure 47. Successful internal intra-cell TCH TCH HSCSD handover from two to onechannel. 150

Figure 48. Successful internal intra-cell TCH TCH HSCSD handover from one tothree channels. 151

Figure 49. Successful internal inter-cell TCH TCH HSCSD handover from three toone channel. 152

Figure 50. Successful internal inter-cell TCH TCH HSCSD handover from two tothree channels. 153

Figure 51. Successful external TCH TCH HSCSD handover from two to twochannels, source BSC. 154

Figure 52. Successful external TCH TCH HSCSD handover from four to onechannel, target BSC. 155

Figure 53. Successful external TCH TCH HSCSD handover from one to twochannels, target BSC. 156

Figure 54. Internal intra-cell direct access from regular DCCH to a super-reuseTRX. 157

Figure 55. Internal inter-cell direct access from parent DCCH to the child or parentTRX. 158

Figure 56. Internal inter-cell direct access from the TCH on a child TRX to the TCHon a parent TRX. 159

Figure 57. Handover attempt due to a BSC controlled TRHO. 160

Figure 58. Handover attempt due to DADL/B. 161


Summary of changes

Changes between document issues are cumulative. Therefore, the latest documentissue contains all changes made to previous issues.

Changes made between issues 7 and 6

1. Introduction

The following new counters added: 004144-004173

2. Counters


The information updated for the following counters: 004133-004136


1. Introduction


2. Counters


The information updated for the following counters: 004007, 004036, 004038


2. Counters

The information updated for the following counter: 004130

3. Signalling Charts

Counter 004130 added to the Signalling Chart 1



1 BSC Counters: Handover MeasurementThe handover measurement registers information concerning the number ofhandovers (HO) controlled by the Mobile Switching Centre (MSC) or the BaseStation Controller (BSC). The recorded items of data comprise the number of theincoming, outgoing, or intra-cell HOs, and the number of successful andunsuccessful attempts, seizures, and HOs. The HOs are sorted according todirection, where appropriate. This measurement type collects one set of results foreach cell. Signalling charts are drawn with the accuracy of message interface.

For more information on the documentation of the counters, with an exampletable and an explanation of the table fields, see BSC Counters: GeneralInformation on Measurements and Observations.

MSC incoming counters:

MSC I success HO 004000

MSC I unsuccessful HO due lack 004001

MSC I unsuccessful HO due conn 004002

MSC I unsuccessful HO due BSS problem 004003

MSC I TCH TCH 004043

MSC I SDCCH TCH 004044

MSC I SDCCH 004045

MSC I TCH TCH attempt 004046

MSC I SDCCH TCH attempt 004047

MSC I SDCCH attempt 004048

MSC I end of HO 004080

MSC I att switch circuit pool 004092

MSC I success switch circuit pool 004093

MSC I unsuccessful due A interface circuit 004101

MSC I call possible dropped during HO 004108

MSC I attempt for HSCSD 004114



MSC outgoing counters:

MSC I success for HSCSD 004115

MSC I success increased for HSCSD 004116

MSC I success decreased for HSCSD 004117

MSC O success HO 004004

MSC O generated HO required messages 004005

MSC O unsuccessful HO due return 004006

MSC O end of HO 004007

MSC O end of HO due BSS 004008

MSC O generated HO command messages 004009

MSC O HO not allowed 004037

MSC O call clear during HO 004041

MSC O TCH TCH 004049

MSC O SDCCH TCH 004050

MSC O SDCCH 004051

MSC O TCH TCH attempt 004052

MSC O SDCCH TCH attempt 004053

MSC O SDCCH attempt 004054

MSC O fail lack 004055

MSC O attempt switch circuit pool 004094

MSC O success switch circuit pool 004095

MSC O adjacent cell identification error 004100

MSC O unsuccessful due a if crc 004102

MSC O call dropped during HO 004107

MSC O attempt for HSCSD 004112

MSC O success for HSCSD 004113



BSC incoming counters:

BSC outgoing counters:

BSC I success HO 004010

BSC I unsuccessful HO due lack 004011

BSC I unsuccessful HO due conn 004012

BSC I unsuccessful HO due BSS problem 004013

BSC I TCH TCH 004056

BSC I SDCCH TCH 004057

BSC I SDCCH 004058

BSC I TCH TCH attempt 004059

BSC I SDCCH TCH attempt 004060

BSC I SDCCH attempt 004061

BSC I nonopt 004062

BSC I nonopt attempt 004063

BSC I end of HO 004081

BSC I dropped calls 004083

BSC I unsuccessful due A interface circuit type 004097

BSC I attempt for HSCSD 004120

BSC I success for HSCSD 004121

BSC I success increased for HSCSD 004122

BSC I success decreased for HSCSD 004123

BSC O success HO 004014

BSC O unsuccessful HO due return 004015

BSC O end of HO 004016

BSC O end of HO due BSS 004017

BSC O HO not allowed 004038

BSC O call clear during HO 004042

BSC O TCH TCH 004064

BSC O SDCCH TCH 004065



BSC Intra-cell handover counters:

BSC O SDCCH 004066

BSC O TCH TCH attempt 004067

BSC O SDCCH TCH attempt 004068

BSC O SDCCH attempt 004069

BSC O nonopt 004070

BSC O nonopt attempt 004071

BSC O fail lack 004072

BSC O dropped calls 004084

BSC O unsuccessful A interface circuit type 004096

BSC O attempt for HSCSD 004118

BSC O success for HSCSD 004119

Intra-cell success HO 004018

Intra-cell unsuccessful HO due lack 004019

Intra-cell unsuccessful HO due move 004020

Intra-cell unsuccessful HO due BSS problem 004021

Intra-cell unsuccessful HO due return 004022

Intra-cell HO not allowed 004036

Intra-cell call cleared during HO 004039

Cell TCH TCH 004073

Cell SDCCH TCH 004074

Cell SDCCH 004075

Cell TCH TCH attempt 004076

Cell SDCCH TCH attempt 004077

Cell SDCCH attempt 004078

Cell dropped calls 004085

Intra-cell unsuccessful A interface circuit type 004098

Intra-cell attempt for HSCSD 004124



Intra-segment handover counters:

Handover cause counters:

Intra-cell success for HSCSD 004125

Intra-cell success increased for HSCSD 004126

Intra-cell success decreased for HSCSD 004127

Successful SDCCH-SDCCH HO between BTSs within asegment

004131

Successful TCH-TCH HO between BTSs within a segment 004132

Inter band attempted SDCCH-SDCCH HO between BTSswithin a segment

004133

Inter band successful SDCCH-SDCCH HO between BTSswithin a segment

004134

Inter band attempted TCH-TCH HO between BTSs within asegment

004135

Inter band successful TCH-TCH HO between BTSs within asegment

004136

Inter BTS-type attempted SDCCH-SDCCH HO within asegment

004137

Inter BTS-type successful SDCCH-SDCCH HO within asegment

004138

Inter BTS-type attempted TCH-TCH HO within a segment 004139

Inter BTS-type successful TCH-TCH HO within a segment 004140

Cause uplink quality 004023

Cause uplink level 004024

Cause downlink quality 004025

Cause downlink level 004026

Cause distance 004027

Cause response to MSC invocation 004028

Cause high interference on uplink 004029

Cause high interference on downlink 004030

Cause umbrella HO 004031



Non-relevant counters:

Cause power budget HO 004032

Cause HO started by OMC 004033

Cause HO started by traffic reason 004035

Cause directed retry 004079

Cause pre-emption 004086

Cause field drop 004087

Cause low distance 004088

Cause bad C/I ratio 004089

Cause good C/I ratio 004090

HO due slow moving MS 004091

HO attempt due switch circuit pool 004099

HO from normal to extended area 004103

HO from extended to normal area 004104

HO due to MS slow speed 004105

HO due to MS high speed 004106

HO attempt due to bad RX level on super 004109

HO attempt due to good RX level on regular 004110

HO attempt due ERFD 004111

HO attempt due to direct access 004128

HO attempt due DADLB 004129

HO attempt due to GPRS 004130

Intra cell HO attempts due to HSCSD traffic 004141

HO attempts due to channel rate change from AMR FR toAMR HR

004142

HO attempts due to channel rate change from AMR HR toAMR FR

004143

Cause HO started by channel administration 004034

MSC I call clear during HO 004040

BSC O MS required enquiry proc 004082



Inter-System Handover counters:

Common BCCH Control for GSM counters:

MSC I TCH HO from WCDMA RAN attempt 004144

MSC I WCDMA RAN TCH HO attempt unsucc due lack 004145

MSC I WCDMA RAN HO attempt unsucc due BSS problem 004146

MSC I WCDMA RAN end of HO 004147

MSC I unsuccess HO WCDMA RAN due conn 004148

MSC I HO WCDMA RAN TCH success 004149

MSC O TCH HO to WCDMA RAN attempt 004150

MSC O HO to WCDMA RAN not allowed 004151

MSC O end of HO to WCDMA RAN due BSS 004152

MSC O gen inter system to WCDMA RAN handover reqmessages

004153

MSC O gen inter system to WCDMA RAN handover commessages

004154

MSC O to WCDMA RAN fail lack 004155

MSC O end of HO to WCDMA RAN 004156

MSC O call drop during HO to WCDMA RAN 004157

MSC O to WCDMA RAN success TCH HO 004158

Successful HO inter band TCH 004159

Unsuccessful HO inter band TCH 004161

HO attempt inter band due level 004163

Unsucc HO inter band due level 004164

Succ HO inter band due level 004165

Inter segment success SDCCH HO between bands 004166

Inter segment success TCH HO between bands 004168



Multi BCF Control counters:

Spare counters:

Related topics

Counters of Handover Measurement

Signalling charts of Handover Measurement

Successful HO inter BTS type TCH 004160

Unsuccessful HO inter BTS type TCH 004162

Inter segment success SDCCH HO between BTS types 004167

Inter segment success TCH HO between BTS types 004169

Spare 004170

Spare 004171

Spare 004172

Spare 004173



2 Counters of Handover Measurement

No

COUNTER NAME

RELEASE/CHANGED

004000

MSC I SUCCESS HO

S1

TRIGGER POINT(S) See figures:

• Successful external TCH to TCH handover, target BSC

• Successful external SDCCH to SDCCH handover, target BSC

• External directed retry, target BSC

• Successful external TCH TCH HSCSD handover from four to onechannel, target BSC

• Successful external TCH TCH HSCSD handover from one to twochannels, target BSC

EXPLANATION Number of successful incoming HOs controlled by the MSC.

UPDATED When the HO (SDCCH to SDCCH, SDCCH to TCH or TCH to TCH)is completed.

DEPENDENCIES When one of the counters 004043, 004044 or 004045 is updated.This counter represents their sum.

No

COUNTER NAME

RELEASE/CHANGED

004001

MSC I UNSUCCESS HO DUE LACK

S1

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover due to alack of resources, target BSC

EXPLANATION Number of incoming HOs, controlled by the MSC, that areunsuccessful due to a lack of radio resources.



UPDATED a) When no SDCCH is available for an SDCCH HO.

b) When no TCH is available for a TCH HO.

c) When no TCH is available for an SDCCH to TCH HO.

IMPACT HO failure

REASON Internal

No

COUNTER NAME

RELEASE/CHANGED

004001

MSC I UNSUCCESS HO DUE LACK

S1

No

COUNTER NAME

RELEASE/CHANGED

004002

MSC I UNSUCCESS HO DUE CONN

S1

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover due to aradio link failure during handover, target BSC

EXPLANATION Number of incoming HOs, controlled by the MSC, that areunsuccessful due to a connection failure.

UPDATED When the connection between the MS and the BTS is broken (on thetarget channel), that is, when a message carrying an indication of aconnection failure is received (radio link failure or transcoder failure).

IMPACT HO failure

REASON External/Abis interface

No

COUNTER NAME

RELEASE/CHANGED

004003

MSC I UNSUCCESS HO DUE BSS PROBLEM

S1

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover due to afailure in the activation of a new channel

EXPLANATION Number of incoming HOs, controlled by the MSC, that areunsuccessful because of BSS problems.

UPDATED When the radio channel activation fails.

IMPACT HO failure




No

COUNTER NAME

RELEASE/CHANGED

004004

MSC O SUCCESS HO

S1


• Successful external TCH to TCH handover, source BSC

• Successful external SDCCH to SDCCH handover, source BSC

• External directed retry, source BSC

• Successful handover type reselection from an internal intra-cellTCH to TCH handover to an external handover due to switchingcircuit pool

• Successful handover type reselection from an internal inter-cellTCH to TCH handover to an external handover due to switchingthe circuit pool

• Successful external TCH TCH HSCSD handover from two to twochannels, source BSC

EXPLANATION Number of successful outgoing HOs controlled by the MSC.


DEPENDENCIES This counter is updated when one of the counters 004049, 004050or 004051 is updated. This counter represents their sum.



No

COUNTER NAME

RELEASE/CHANGED

004005

MSC O GEN HO REQUIRED MESSAGES

S1





• Unsuccessful external TCH to TCH handover due to a lack ofresources, source BSC

• Unsuccessful external TCH to TCH handover due to MSreturning to the old channel, source BSC

• Unsuccessful external TCH to TCH handover due to call clearingduring handover, source BSC

• Successful handover type reselection from an internal intra-cellTCH to TCH handover to an external handover due to switchingthe circuit pool


• Unsuccessful external TCH to TCH handover because the MSCrejects the handover due to various causes, source BSC

• Unsuccessful external TCH to TCH handover due to GSM timerT8 expiry, source BSC

• Unsuccessful external TCH to TCH handover due to adjacent cellerror, source BSC

• Unsuccessful external TCH or TCH handover, source BSC


EXPLANATION Total number of HO_REQUIRED messages that are generated byoutgoing HOs controlled by the MSC.

UPDATED When the BSC sends the HANDOVER_ REQUIRED message tothe MSC.



No

COUNTER NAME

RELEASE/CHANGED

004006

MSC O UNSUCCESS HO DUE RETURN

S1

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover due to MSreturning to the old channel, source BSC

EXPLANATION Number of outgoing HOs, controlled by the MSC, that areunsuccessful because the MS returns to the source channel.

UPDATED When the MS returns to the source channel.

IMPACT HO failure.

REASON External/Abis interface.

No

COUNTER NAME

RELEASE/CHANGED

004007

MSC O END OF HO

S1




EXPLANATION Number of the end of handover procedures (outgoing HO controlledby the MSC).

UPDATED a) When the GSM timer T8 expires (CLEAR_COMMAND messagenot received).

b) When the HO is rejected with another cause thanswitch_crc_pool, cip_type_mismatch, invalid_cell,no_radio_res_avail, req_terr_res_unava or T7_expiry.

c) When the MSC sends a CLEAR_COMMAND message with areason other than handover successful or call control to the BSC.

d) When there is an internal conflict with the A interface.

IMPACT HO failure (b and d)

Possibly call cleared (a and c)

REASON External/A interface



No

COUNTER NAME

RELEASE/CHANGED

004008

MSC O END OF HO DUE BSS

S1

TRIGGER POINT(S) See figureUnsuccessful external TCH to TCH handover due to aradio link failure during handover, source BSC

EXPLANATION Number of the end of handover procedures due to BSS problems(outgoing HO controlled by the MSC).

UPDATED When the connection between the MS and the BTS is broken (on thesource channel), that is, when a message carrying an indication of aconnection failure is received (radio link failure or transcoder failure).

IMPACT The call may possibly be cleared.

REASON External/Abis interface.

No

COUNTER NAME

RELEASE/CHANGED

004009

MSC O GEN HO COM MESSAGES

S1





• Unsuccessful external TCH to TCH handover due to MSreturning to the old channel, source BSC

• Unsuccessful external TCH to TCH handover due to call clearingduring handover, source BSC





EXPLANATION Number of HANDOVER_COMMAND messages that are generatedby outgoing HOs controlled by the MSC.

UPDATED When the HANDOVER_COMMAND is sent to the MS.



No

COUNTER NAME

RELEASE/CHANGED

004010

BSC I SUCCESS HO

S1


• Successful internal inter-cell TCH to TCH handover

• Successful internal inter-cell SDCCH to SDCCH handover

• Internal inter-cell directed retry, including feature BSS6114 TCHassignment to the super-reuse TRX in IUO

• Successful internal inter-cell TCH TCH HSCSD handover fromthree to one channel

• Successful internal inter-cell TCH TCH HSCSD handover fromtwo to three channels

• Internal inter-cell direct access from parent DCCH to the child orparent TRX

• Internal inter-cell direct access from the TCH on a child TRX tothe TCH on a parent TRX

EXPLANATION Number of successful incoming HOs controlled by the BSC.


DEPENDENCIES When one of the counters 004056, 004057 or 004058 is updated.This counter represents their sum.

No

COUNTER NAME

RELEASE/CHANGED

004011

BSC I UNSUCCESS HO DUE LACK

S1

TRIGGER POINT(S) See figure Unsuccessful internal inter-cell TCH to TCH handoverdue to a lack of resources

EXPLANATION Number of incoming HOs, controlled by the BSC, that areunsuccessful due to a lack of resources.




DEPENDENCIES Counter 004072 is updated along with this counter.

IMPACT HO failure

REASON Internal



No

COUNTER NAME

RELEASE/CHANGED

004012

BSC I UNSUCCESS HO DUE CONN

S1


• Unsuccessful internal inter-cell TCH to TCH handover due tolosing the MS during handover. The GSM timer T3103 expires

• Unsuccessful internal inter-cell TCH to TCH handover due to MSreturning to the old channel

EXPLANATION Number of incoming HOs, controlled by the BSC, that areunsuccessful due to a connection failure (the MS fails to move to thetarget channel).

UPDATED a) When the MS returns to the source channel

b) When the MS is lost (GSM timer T3103 expires).

c) When the connection between the MS and the BTS is broken (onthe target channel), that is, when a message carrying an indicationof a connection failure is received (radio link failure or transcoderfailure).

DEPENDENCIES a) Counter 004015 is updated along with this counter.

b) Counters 004016, 004083 and 004084 are updated along withthis counter.

c) Counter 004016 or 004042 is updated along with this counter.

IMPACT HO failure

The call may possibly be cleared




No

COUNTER NAME

RELEASE/CHANGED

004013

BSC I UNSUCCESS HO DUE BSS PROBLEM

S1


• Unsuccessful internal inter-cell TCH to TCH handover due to afailure in the activation of a new channel

• Unsuccessful internal inter-cell TCH to TCH handover caused byinternal timer expiry or a failure in the connection of a bi-directional speech path

EXPLANATION Number of incoming HOs, controlled by the BSC, that areunsuccessful due to BSS problems.

UPDATED a) When the radio channel activation fails.

b) When switching from a unidirectional to a bi-directional speechpath fails.



IMPACT a) HO failure

b) Call cleared

REASON External/Abis interface or Internal/A -interface



No

COUNTER NAME

RELEASE/CHANGED

004014

BSC O SUCCESS HO

S1









EXPLANATION Number of successful outgoing HOs controlled by the BSC.



No

COUNTER NAME

RELEASE/CHANGED

004015

BSC O UNSUCCESS HO DUE RETURN

S1

TRIGGER POINT(S) See figure Unsuccessful internal inter-cell TCH to TCH handoverdue to MS returning to the old channel

EXPLANATION Number of outgoing HOs, controlled by the BSC, that areunsuccessful because the MS returns to the source channel.



IMPACT HO failure




No

COUNTER NAME

RELEASE/CHANGED

004016

BSC O END OF HO

S1


• Unsuccessful internal inter-cell TCH to TCH handover due to afailure in the activation of a new channel


EXPLANATION Number of the end of handover procedures that are related tooutgoing HOs controlled by the BSC.

UPDATED a) When the MS is lost (GSM timer T3103 expires).

b) When radio channel activation fails.

c) When the connection between the MS and the BTS is broken (onthe target channel), that is, when a message carrying an indicationof a connection failure is received (radio link failure or transcoderfailure).

DEPENDENCIES a) Counters 004012, 004083 and 004084 are updated along withthis counter.

b) Counter 004013 is updated along with this counter.

c) Counter 004012 is updated along with this counter.

IMPACT a) Call cleared

b) and c) HO failure




No

COUNTER NAME

RELEASE/CHANGED

004017

BSC O END OF HO DUE BSS

S1


• Unsuccessful internal inter-cell TCH to TCH handover due to aradio link failure during handover


EXPLANATION Number of outgoing HOs, controlled by the BSC, that areunsuccessful due to BSS problems.

UPDATED a) When the connection between the MS and the BTS is broken (onthe source channel), that is, when a message carrying an indicationof a connection failure is received (radio link failure or transcoderfailure) before a HO_COMMAND message.




IMPACT Call cleared.




No

COUNTER NAME

RELEASE/CHANGED

004018

INT CELL SUCCESS HO

S1


• Successful internal intra-cell TCH to TCH handover

• Successful internal intra-cell SDCCH to SDCCH handover

• Internal intra-cell directed retry including feature BSS6114: TCHassignment to the super-reuse TRX in IUO

• Successful internal intra-cell TCH TCH HSCSD handover fromtwo to one channel

• Successful internal intra-cell TCH TCH HSCSD handover fromone to three channels

• Internal intra-cell direct access from regular DCCH to a super-reuse TRX

EXPLANATION Number of successful intra-cell HOs.

UPDATED When the HO (SDCCH to SDCCH, TCH to TCH or SDCCH to TCH)is completed.


No

COUNTER NAME

RELEASE/CHANGED

004019

INT CELL UNSUCCESS HO DUE LACK

S1

TRIGGER POINT(S) See figure Unsuccessful internal intra-cell TCH to TCH handoverdue to lack of resources

EXPLANATION Number of intra-cell HOs that are unsuccessful due to a lack ofresources.




IMPACT HO failure

REASON Internal



No

COUNTER NAME

RELEASE/CHANGED

004020

INT CELL UNSUCCESS HO DUE MOVE

S1

TRIGGER POINT(S) See figure Unsuccessful internal intra-cell TCH to TCH handoverdue to losing the MS during handover. The GSM timer T3107 expires

EXPLANATION Number of intra-cell HOs that are unsuccessful because the MScannot either move to the target channel or return to the sourcechannel.

UPDATED When the MS is lost (GSM timer T3107 expires).


IMPACT Call cleared


No

COUNTER NAME

RELEASE/CHANGED

004021

INT CELL UNSUCCESS HO DUE BSS PROBLEM

S1

TRIGGER POINT(S) See figure Unsuccessful internal intra-cell TCH to TCH handoverdue to a failure in the activation of a new channel

EXPLANATION Number of unsuccessful intra-cell HOs due to BSS problems.

UPDATED a) When a radio channel activation fails.

b) When the physical context request fails.

c) When the connection between the MS and the BTS is broken, thatis, when a message carrying an indication of a connection failure isreceived (radio link failure or transcoder failure).

d) When switching from a unidirectional to a bi-directional speechpath fails.

DEPENDENCIES d) Counter 004085 is updated along with this counter.

IMPACT a) and b) HO failure

c) Possibly call cleared d) Call cleared

REASON External/Abis interface or Internal/A -interface



No

COUNTER NAME

RELEASE/CHANGED

004022

INT CELL UNSUCCESS HO DUE RETURN

S1


• Unsuccessful internal intra-cell TCH to TCH handover due to MSreturning to the old channel

• Unsuccessful internal intra-cell TCH to TCH handover, caused byan internal timer expiry in the BSC or aCONNECTION_FAILURE, ERROR_INDICATION, orERROR_REPORT message coming to the target channel

EXPLANATION Number of unsuccessful intra-cell HOs due to the MS's return to thesource channel.


IMPACT HO failure


No

COUNTER NAME

RELEASE/CHANGED

004023

CAUSE UPLINK QUALITY

S1






EXPLANATION Number of HO attempts caused by uplink quality (outgoing).

UPDATED When a HO is started due to uplink quality.



No

COUNTER NAME

RELEASE/CHANGED

004024

CAUSE UPLINK LEVEL

S1






EXPLANATION Number of HO attempts caused by uplink level (outgoing).

UPDATED When a HO is started due to uplink level.

No

COUNTER NAME

RELEASE/CHANGED

004025

CAUSE DOWNLINK QUALITY

S1








EXPLANATION Number of HO attempts caused by downlink quality (outgoing).

UPDATED When a HO is started due to downlink quality.



No

COUNTER NAME

RELEASE/CHANGED

004026

CAUSE DOWNLINK LEVEL

S1






EXPLANATION Number of HO attempts caused by downlink level (outgoing).

UPDATED When a HO is started due to downlink level.

No

COUNTER NAME

RELEASE/CHANGED

004027

CAUSE DISTANCE

S1








EXPLANATION Number of HO attempts caused by distance (outgoing).

UPDATED When a HO is started due to distance.



No

COUNTER NAME

RELEASE/CHANGED

004028

CAUSE RESPONSE TO MSC INVOCATION

S1






EXPLANATION Number of HO attempts due to a response to an invocation from theMSC (outgoing).

UPDATED When a HO is started due to a response to an MSC invocation.

No

COUNTER NAME

RELEASE/CHANGED

004029

CAUSE HIGH INT ON UPLINK

S1








EXPLANATION Number of HO attempts caused by high interference on uplink(outgoing).

UPDATED When a HO is started due to high interference on uplink.



No

COUNTER NAME

RELEASE/CHANGED

004030

CAUSE HIGH INT ON DOWNLINK

S1








EXPLANATION Number of HO attempts caused by high interference on downlink(outgoing).

UPDATED When a HO is started due to high interference on downlink.

No

COUNTER NAME

RELEASE/CHANGED

004031

CAUSE UMBRELLA HO

S1







EXPLANATION Number of attempts to umbrella HO (outgoing).

UPDATED When a HO is started due to an umbrella HO.



No

COUNTER NAME

RELEASE/CHANGED

004032

CAUSE POWER BUDGET HO

S1






EXPLANATION Number of attempts to power budget HO (outgoing).

UPDATED When a HO is started due to a power budget HO.

No

COUNTER NAME

RELEASE/CHANGED

004033

CAUSE HO STARTED BY OMC

S1








EXPLANATION Number of HO attempts started by the O&M (outgoing).

UPDATED When a HO is started by OMC.

No

COUNTER NAME

RELEASE/CHANGED

004034

CAUSE HO STARTED BY CHANNEL ADM

S1

EXPLANATION Number of HO attempts started by channel administration(outgoing).

UPDATED This counter is NOT relevant.



No

COUNTER NAME

RELEASE/CHANGED

004035

CAUSE HO STARTED BY TRAFFIC REASON

S8

TRIGGER POINT(S) See figure Handover attempt due to a BSC controlled TRHO

EXPLANATION Number of HO attempts due to TRHO, controlled by the BSC.

UPDATED When a HO is started due to BSC TRHO.

RELATED TO A FEATURE BSS8123 Advanced Multilayer Handling

No

COUNTER NAME

RELEASE/CHANGED

004036

INT CELL HO NOT ALLOWED

S1

TRIGGER POINT(S) See figure Unsuccessful internal intra-cell TCH to TCH handoverbecause a handover is not allowed at this phase of the call

EXPLANATION Number of HOs that are unsuccessful because no HOs are allowed(intra-cell HO).

UPDATED a) When HO execution is not allowed in the current phase of the callin progress.

b) When a HO is interrupted because an assignment procedure hasbeen started during a HO but before the BSC has sent anASSIGNMENT_COMMAND or HANDOVER_COMMAND messageto the MS.

IMPACT HO failure

REASON Internal



No

COUNTER NAME

RELEASE/CHANGED

004037

MSC O HO NOT ALLOWED

S1


• Unsuccessful external TCH to TCH handover because ahandover is not allowed, source BSC


EXPLANATION Number of outgoing HOs, controlled by the MSC, that areunsuccessful because no HOs are allowed.

UPDATED a) When HO execution is not allowed in the current phase of the callin progress.

b) When the parameter DISABLE_INT_HO is set and an underlayoverlay HO start is attempted.

c) When DISABLE_EXT_DR is set and DR is attempted.

d) When external HO is not possible due to FACCH call setup.

e) When an external HO is not possible because the neighbouringcell is defined to be the normal area of an extended cell from anotherBSC.

IMPACT HO failure

REASON Internal

No

COUNTER NAME

RELEASE/CHANGED

004038

BSC O HO NOT ALLOWED

S1

TRIGGER POINT(S) See figure Unsuccessful internal inter-cell TCH to TCH handoverbecause a handover is not allowed at this phase of the call

EXPLANATION Number of outgoing HOs, controlled by the BSC, that areunsuccessful because no HOs are allowed.

UPDATED - When HO execution is not allowed in the current phase of the call inprogress.

- When an HO is interrupted because the assignment procedure basbeen started during a HO but before the BSC has sent aHANDOVER_COMMAND message to the MS.




IMPACT HO failure

REASON External/A interface

No

COUNTER NAME

RELEASE/CHANGED

004038

BSC O HO NOT ALLOWED

S1

No

COUNTER NAME

RELEASE/CHANGED

004039

INT CELL CALL CLEAR DURING HO

S1

TRIGGER POINT(S) See figure Unsuccessful internal intra-cell TCH to TCH handoverdue to call clearing during handover

EXPLANATION Number of intra-cell HOs that are unsuccessful because the call iscleared.

UPDATED a) When the subscriber clears the call during the HO.

b) When channel blocking is started during the HO.

REASON External

No

COUNTER NAME

RELEASE/CHANGED

004040

MSC I CALL CLEAR DURING HO

S1

UPDATED This counter is NOT relevant.



No

COUNTER NAME

RELEASE/CHANGED

004041

MSC O CALL CLEAR DURING HO

S1

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover due to callclearing during handover, source BSC

EXPLANATION Number of outgoing HOs, controlled by the MSC, that areunsuccessful because the call is cleared during the HO.



c) When the MS has sent messages concerning

- A interface speech circuits

- state changes of the BSSAP subsystem

- abnormal release of the SCCP connection

d) When the reset of circuits are received from the MSC

e) When there is a BCSU restart (if the TCHs related to the HO arein that BCSU).

IMPACT Call cleared

REASON Internal or external/A interface

No

COUNTER NAME

RELEASE/CHANGED

004042

BSC O CALL CLEAR DURING HO

S1

TRIGGER POINT(S) See figure Unsuccessful internal inter-cell TCH to TCH handoverdue to call clearing during handover

EXPLANATION Number of outgoing HOs, controlled by the BSC, that areunsuccessful because the call is cleared.




IMPACT Call cleared

REASON Internal or external / A interface



No

COUNTER NAME

RELEASE/CHANGED

004043

MSC I TCH TCH

S2





EXPLANATION Number of successful incoming TCH to TCH HOs controlled by theMSC.

UPDATED When the HO is completed.


No

COUNTER NAME

RELEASE/CHANGED

004044

MSC I SDCCH TCH

S2

TRIGGER POINT(S) See figure External directed retry, target BSC

EXPLANATION Number of successful incoming SDCCH to TCH HOs controlled bythe MSC.

UPDATED When a directed retry procedure is completed.


No

COUNTER NAME

RELEASE/CHANGED

004045

MSC I SDCCH

S2

TRIGGER POINT(S) See figure Successful external SDCCH to SDCCH handover, targetBSC

EXPLANATION Number of successful incoming SDCCH to SDCCH HOs controlledby the MSC.





No

COUNTER NAME

RELEASE/CHANGED

004046

MSC I TCH TCH AT

S2



• Unsuccessful external TCH to TCH handover due to a lack ofresources, target BSC

• Unsuccessful external TCH to TCH handover due to a failure inthe activation of a new channel, target BSC

• Unsuccessful external TCH to TCH handover due to MSreturning to the old channel, target BSC

• Unsuccessful external TCH to TCH handover because no radioresources are available due to switch_crc_pool, target BSC

• Unsuccessful external TCH to TCH handover due to a radio linkfailure during handover, target BSC

• Unsuccessful external TCH to TCH handover, target BSC



EXPLANATION Number of attempts to incoming TCH to TCH HOs controlled by theMSC.

UPDATED When the HO attempt is started.

No

COUNTER NAME

RELEASE/CHANGED

004047

MSC I SDCCH TCH AT

S2

TRIGGER POINT(S) See figure External directed retry, target BSC

EXPLANATION Number of attempts to incoming SDCCH to TCH HOs controlled bythe MSC.

UPDATED When a directed retry procedure is started.

RELATED TO A FEATURE Directed Retry



No

COUNTER NAME

RELEASE/CHANGED

004048

MSC I SDCCH AT

S2

TRIGGER POINT(S) See figure Successful external SDCCH to SDCCH handover, targetBSC

EXPLANATION Number of attempts to incoming SDCCH to SDCCH HOs controlledby the MSC.


No

COUNTER NAME

RELEASE/CHANGED

004049

MSC O TCH TCH

S2






EXPLANATION Number of successful outgoing TCH to TCH HOs controlled by theMSC.


No

COUNTER NAME

RELEASE/CHANGED

004050

MSC O SDCCH TCH

S2

TRIGGER POINT(S) See figure External directed retry, source BSC

EXPLANATION Number of successful outgoing SDCCH to TCH HOs controlled bythe MSC.

UPDATED When a directed retry procedure is completed.




No

COUNTER NAME

RELEASE/CHANGED

004051

MSC O SDCCH

S2

TRIGGER POINT(S) See figure Successful external SDCCH to SDCCH handover, sourceBSC

EXPLANATION Number of successful outgoing SDCCH to SDCCH HOs controlledby the MSC.


No

COUNTER NAME

RELEASE/CHANGED

004052

MSC O TCH TCH AT

S2






EXPLANATION Number of attempts to outgoing TCH to TCH HOs controlled by theMSC.


No

COUNTER NAME

RELEASE/CHANGED

004053

MSC O SDCCH TCH AT

S2

TRIGGER POINT(S) See figure External directed retry, source BSC

EXPLANATION Number of attempts to outgoing SDCCH to TCH HOs controlled bythe MSC.

UPDATED When a directed retry procedure is started.




No

COUNTER NAME

RELEASE/CHANGED

004054

MSC O SDCCH AT

S2

TRIGGER POINT(S) See figure Successful external SDCCH to SDCCH handover, sourceBSC

EXPLANATION Number of attempts to outgoing SDCCH to SDCCH HOs controlledby the MSC.


No

COUNTER NAME

RELEASE/CHANGED

004055

MSC O FAIL LACK

S2


• Unsuccessful external TCH to TCH handover due to a lack ofresources, source BSC


• Unsuccessful external TCH or TCH handover, source BSC

EXPLANATION Number of outgoing HOs, controlled by the MSC, that areunsuccessful because there are no radio resources available in thetarget cell.

UPDATED a) When no SDCCH is available in the target cell for an SDCCH HO.

b) When no TCH is available in the target cell for a TCH HO.

c) When no TCH is available in the target cell for an SDCCH to TCHHO.

d) When no terrestrial channel is available in the target cell.

e) When the GSM timer T7 expires

IMPACT HO failure

REASON Internal



No

COUNTER NAME

RELEASE/CHANGED

004056

BSC I TCH TCH

S2






EXPLANATION Number of successful incoming TCH to TCH HOs controlled by theBSC.



No

COUNTER NAME

RELEASE/CHANGED

004057

BSC I SDCCH TCH

S2/S7




EXPLANATION Number of successful incoming SDCCH to TCH HOs controlled bythe BSC.

UPDATED a) When a directed retry procedure is completed.

b) When the direct access to the super-reuse TRX is completed.

c) When the TCH assignment to the super-reuse TRX is completed.


RELATED TO A FEATURE Directed Retry, BSS6114 TCH assignment to the super-reuse TRXin IUO and BSS7057 Direct Access to Super-Reuse TRX in IUO.



No

COUNTER NAME

RELEASE/CHANGED

004058

BSC I SDCCH

S2

TRIGGER POINT(S) See figure Successful internal inter-cell SDCCH to SDCCHhandover

EXPLANATION Number of successful incoming SDCCH to SDCCH HOs controlledby the BSC.



No

COUNTER NAME

RELEASE/CHANGED

004059

BSC I TCH TCH AT

S2






EXPLANATION Number of attempts to incoming TCH to TCH HOs controlled by theBSC.




No

COUNTER NAME

RELEASE/CHANGED

004060

BSC I SDCCH TCH AT

S2/S7




EXPLANATION Number of attempts to incoming SDCCH to TCH HOs controlled bythe BSC.

UPDATED a) When a directed retry procedure is started.

b) When the direct access to the super-reuse TRX is started.

c) When the TCH assignment to the super-reuse TRX is started.


No

COUNTER NAME

RELEASE/CHANGED

004061

BSC I SDCCH AT

S2


EXPLANATION Number of attempts to incoming SDCCH to SDCCH HOs controlledby the BSC.




No

COUNTER NAME

RELEASE/CHANGED

004062

BSC I NONOPT

S2







EXPLANATION Number of successful incoming HOs to a non-optimum cellcontrolled by the BSC.

UPDATED When a HO to a target cell other than the first one in the list ofcandidate target cells is completed.

No

COUNTER NAME

RELEASE/CHANGED

004063

BSC I NONOPT AT

S2





• Unsuccessful internal inter-cell TCH to TCH handover due to alack of resources

• Unsuccessful internal inter-cell TCH to TCH handover becauseno radio resources are available due to switch_crc_pool



EXPLANATION Number of attempts to incoming HOs to a non-optimum cellcontrolled by the BSC.

UPDATED When a HO to a target cell other than the first one in the list ofcandidate target cells is started.



No

COUNTER NAME

RELEASE/CHANGED

004064

BSC O TCH TCH

S2






EXPLANATION Number of successful outgoing TCH to TCH HOs controlled by theBSC.



No

COUNTER NAME

RELEASE/CHANGED

004065

BSC O SDCCH TCH

S2/S7




EXPLANATION Number of successful outgoing TCH HOs controlled by the BSC.

UPDATED a) When a directed retry procedure is completed.

b) When the direct access from the SDCCH to TCH on a super-reuse TRX is completed.

c) When the intelligent directed retry is completed.

d) When the TCH assignment to a super-reuse TRX is completed.





No

COUNTER NAME

RELEASE/CHANGED

004066

BSC O SDCCH

S2


EXPLANATION Number of successful outgoing SDCCH to SDCCH HOs controlledby the BSC.



No

COUNTER NAME

RELEASE/CHANGED

004067

BSC O TCH TCH AT

S2/S7






EXPLANATION Number of attempts to outgoing TCH to TCH HOs controlled by theBSC.


RELATED TO A FEATURE BSS7057 Direct Access to Super-Reuse TRX in IUO.



No

COUNTER NAME

RELEASE/CHANGED

004068

BSC O SDCCH TCH AT

S2/S7




EXPLANATION Number of attempts to outgoing SDCCH to TCH HOs controlled bythe BSC.

UPDATED a) When a directed retry procedure is started.

b) When the direct access from the SDCCH to TCH on a super-reuse TRX is started.

c) When the intelligent directed retry is started.

d) When the TCH assignment to a super-reuse TRX is started.


No

COUNTER NAME

RELEASE/CHANGED

004069

BSC O SDCCH AT

S2


EXPLANATION Number of attempts to outgoing SDCCH to SDCCH HOs controlledby the BSC.




No

COUNTER NAME

RELEASE/CHANGED

004070

BSC O NONOPT

S2







EXPLANATION Number of successful outgoing HOs to a non-optimum cellcontrolled by the BSC.

UPDATED When a HO to a target cell other than the first one in the list ofcandidate target cells is completed.

No

COUNTER NAME

RELEASE/CHANGED

004071

BSC O NONOPT AT

S2





• Unsuccessful internal inter-cell TCH to TCH handover due to alack of resources




EXPLANATION Number of attempts to outgoing HOs to a non-optimum cellcontrolled by the BSC.

UPDATED When a HO to a target cell other than the first one in the list ofcandidate target cells is started.



No

COUNTER NAME

RELEASE/CHANGED

004072

BSC O FAIL LACK

S2

TRIGGER POINT(S) See figure Unsuccessful internal inter-cell TCH to TCH handoverdue to a lack of resources

UPDATED a) When no SDCCH is available in the target cell for an SDCCH HO.

b) When no TCH is available in the target cell for a TCH HO.

c) When no TCH is available in the target cell for an SDCCH to TCHHO.

IMPACT HO failure

REASON Internal

No

COUNTER NAME

RELEASE/CHANGED

004073

CELL TCH TCH

S2





EXPLANATION Number of successful intra-cell (TCH to TCH) HOs.





No

COUNTER NAME

RELEASE/CHANGED

004074

CELL SDCCH TCH

S2/S7




EXPLANATION Number of successful intra-cell (SDCCH to TCH) HOs.

UPDATED a) When a channel assignment to a super-reuse TRX in an IUO DRis completed.

b) When the direct access to a super-reuse TRX is completed.


RELATED TO A FEATURE BSS6114 TCH assignment to the super-reuse TRX in IUO andBSS7057 Direct Access to Super-Reuse TRX in IUO.

No

COUNTER NAME

RELEASE/CHANGED

004075

CELL SDCCH

S2

TRIGGER POINT(S) See figure Successful internal intra-cell SDCCH to SDCCHhandover

EXPLANATION Number of successful intra-cell (SDCCH to SDCCH) HOs.





No

COUNTER NAME

RELEASE/CHANGED

004076

CELL TCH TCH AT

S2





EXPLANATION Number of attempts to intra-cell (TCH to TCH) HOs.


No

COUNTER NAME

RELEASE/CHANGED

004077

CELL SDCCH TCH AT

S2/S7




EXPLANATION Number of attempts to intra-cell (SDCCH to TCH) HOs.

UPDATED a) When a channel assignment to a super-reuse TRX in an IUO DRis started.

b) When the direct access to a super-reuse TRX is started.

RELATED TO A FEATURE BSS6114 TCH assignment to the super-reuse TRX in IUO andBSS7057 Direct Access to Super-Reuse TRX in IUO.

No

COUNTER NAME

RELEASE/CHANGED

004078

CELL SDCCH AT

S2

TRIGGER POINT(S) See figure Successful internal intra-cell SDCCH to SDCCHhandover

EXPLANATION Number of attempts to intra-cell (SDCCH to SDCCH) HOs.




No

COUNTER NAME

RELEASE/CHANGED

004079

CAUSE DIR RETRY

S2/S6





EXPLANATION Number of HO attempts due to directed retry.

RELATED TO A FEATURE Directed Retry, BSS6114 TCH assignment to the super-reuse TRXin IUO.

No

COUNTER NAME

RELEASE/CHANGED

004080

MSC I END OF HO

S2




EXPLANATION Number of end of handover procedures in incoming HOs that arecontrolled by the MSC.

UPDATED a) When the MS returns onto the source channel.

b) When the MS is lost during the HO.

c) When the call is cleared during the HO either by the subscriber, orby messages from the MS concerning

- the start of channel blocking

- the A interface speech circuits


- an abnormal release of the SCCP connection

d) When the call is cleared during the HO by a message receivedfrom the MSC concerning the resetting of the circuits or the BCSUrestart (if the TCHs related to the HO are in that BCSU).



DEPENDENCIES b) Counter 004108 is updated along with this counter.

IMPACT HO failure

Possibly call cleared


No

COUNTER NAME

RELEASE/CHANGED

004080

MSC I END OF HO

S2

No

COUNTER NAME

RELEASE/CHANGED

004081

BSC I END OF HO

S2


• Unsuccessful internal inter-cell TCH to TCH handover because ahandover is not allowed at this phase of the call

• Unsuccessful internal inter-cell TCH to TCH handover due to callclearing during handover

• Unsuccessful internal inter-cell TCH to TCH handover due to aradio link failure during handover

EXPLANATION Number of end of handover procedures in the incoming HOs that arecontrolled by the BSC.

UPDATED a) When it is not allowed to execute a HO at the current phase of thecall.

b) When the call is cleared during the HO.

c) When the connection between the MS and the BTS is broken (onthe source channel), that is, when a message carrying an indicationof a connection failure is received (radio link failure or transcoderfailure).



c) Counter 004017 is updated along with this counter.

IMPACT HO failure

Possibly call cleared




No

COUNTER NAME

RELEASE/CHANGED

004082

BSC O MS REQ ENQ PROC

S2

EXPLANATION Number of MSs required in a HO candidate enquiry.

No

COUNTER NAME

RELEASE/CHANGED

004083

BSC I DROP CALLS

S3




EXPLANATION Number of calls that are dropped during incoming HOs controlled bythe BSC.

UPDATED a) When the MS is lost (timer T3103 expires).




IMPACT Call cleared



No

COUNTER NAME

RELEASE/CHANGED

004084

BSC O DROP CALLS

S3




EXPLANATION Number of calls that are dropped during outgoing HOs controlled bythe BSC.





IMPACT Call cleared

No

COUNTER NAME

RELEASE/CHANGED

004085

CELL DROP CALLS

S3

TRIGGER POINT(S) See figure Unsuccessful internal intra-cell TCH to TCH handoverdue to losing the MS during handover. The GSM timer T3107 expires

EXPLANATION Number of calls dropped during intra-cell HOs.





IMPACT Call cleared



No

COUNTER NAME

RELEASE/CHANGED

004086

CAUSE PREEMPTION

S3








EXPLANATION Number of HO attempts due to pre-emption.

UPDATED When a HO is started due to pre-emption.

No

COUNTER NAME

RELEASE/CHANGED

004087

CAUSE FIELD DROP

S4






EXPLANATION Number of HO attempts caused by rapid field drop.

UPDATED When a HO is started due to rapid field drop.



No

COUNTER NAME

RELEASE/CHANGED

004088

CAUSE LOW DISTANCE

S4








EXPLANATION Number of HO attempts caused by low distance.

UPDATED When a HO is started due to low distance.

No

COUNTER NAME

RELEASE/CHANGED

004089

CAUSE BAD CI RATIO

S4






EXPLANATION Number of HO attempts caused by a poor C/I ratio on the super-reuse frequency.

UPDATED When a HO is started due to a poor C/I ratio.



No

COUNTER NAME

RELEASE/CHANGED

004090

CAUSE GOOD CI RATIO

S4






EXPLANATION Number of HO attempts caused by a good C/I ratio on the super-reuse frequency.

UPDATED When a HO is started due to a good C/I ratio.

No

COUNTER NAME

RELEASE/CHANGED

004091

HO DUE SLOW MOV MS

S5






EXPLANATION Number of HOs caused by a slowly moving MS in the macro cell.

UPDATED When a HO is started due to a slowly moving MS.



No

COUNTER NAME

RELEASE/CHANGED

004092

MSC I ATT SWITCH CIRC POOL

S5




• Unsuccessful external TCH to TCH handover due to a failure inthe activation of a new channel, target BSC


• Unsuccessful external TCH to TCH handover because no radioresources are available due to switch_crc_pool, target BSC

• Unsuccessful external TCH to TCH handover due to a radio linkfailure during handover, target BSC


EXPLANATION Number of HO attempts started due to cause switch_circuit_pool

UPDATED When cause switch_circuit_pool is received in theHANDOVER_REQUIRED message from the A interface.


RELATED TO A FEATURE BSS5010 Half Rate

No

COUNTER NAME

RELEASE/CHANGED

004093

MSC I SUCC SWITCH CIRC POOL

S5




EXPLANATION Number of successful HOs started due to cause switch_circuit_pool.

UPDATED When the HO due to the cause switch_circuit_pool from the Ainterface is completed.





No

COUNTER NAME

RELEASE/CHANGED

004094

MSC O ATT SWITCH CIRC POOL

S5




EXPLANATION Number of HO attempts started due to cause switch_circuit_pool.

UPDATED When cause switch_circuit_pool is sent to the A interface in theHANDOVER_REQUIRED message.



No

COUNTER NAME

RELEASE/CHANGED

004095

MSC O SUCC SWITCH CIRC POOL

S5






EXPLANATION Number of successful HOs started due to cause switch_circuit_pool.

UPDATED When the HO due to cause switch_circuit_ pool from the A interfaceis completed.





No

COUNTER NAME

RELEASE/CHANGED

004096

BSC O UNSUCC A INT CIRC TYPE

S5




EXPLANATION Number of outgoing HOs that are unsuccessful due to a wrong Ainterface circuit type.

UPDATED When an internal outgoing inter-cell HO attempt is interruptedbecause the BSC wants to change the A interface circuit pool beforeTCH allocation.



IMPACT HO failure

REASON External /A interface

No

COUNTER NAME

RELEASE/CHANGED

004097

BSC I UNSUCC A INT CIRC TYPE

S5




EXPLANATION Number of incoming HOs that are unsuccessful due to a wrong Ainterface circuit type.

UPDATED When an internal incoming inter-cell HO attempt is interruptedbecause the BSC wants to change the A interface circuit pool beforeTCH allocation.





IMPACT HO failure


No

COUNTER NAME

RELEASE/CHANGED

004097

BSC I UNSUCC A INT CIRC TYPE

S5

No

COUNTER NAME

RELEASE/CHANGED

004098

INT UNSUCC A INT CIRC TYPE

S5


• Unsuccessful internal intra-cell TCH to TCH handover becauseno radio resources are available due to switch_crc_pool


EXPLANATION Number of HOs unsuccessful due to a wrong A interface circuit type.

UPDATED When an internal intra-cell HO attempt is interrupted because theBSC wants to change the A interface circuit pool before TCHallocation.


IMPACT HO failure




No

COUNTER NAME

RELEASE/CHANGED

004099

HO ATT DUE SWITCH CIRC POOL

S5






EXPLANATION Number of HO attempts started in order to change the A interfacecircuit type.


No

COUNTER NAME

RELEASE/CHANGED

004100

MSC O ADJ CELL ID ERR

S5



• Unsuccessful external TCH to TCH handover due to adjacent cellerror, source BSC

EXPLANATION Number of errors in adjacent cell identification.

UPDATED a) When the BSC notices that the target cell information (BCCHfrequency and/or BSIC) received in the HANDOVER_COMMANDmessage from the MSC differs from that in the source BSDATA (BSSRadio Network Configuration Database).

b) When the MSC rejects the HO attempt due to cause invalid_cellduring a HO from SDCCH to TCH or from TCH to TCH .

RELATED TO A FEATURE BSS5370 Target Cell Identifier Checking in External HO

IMPACT HO failure

REASON Internal. Information on the adjacent cells is incorrect in the BSSRadio Network Configuration Database in the source BSC



No

COUNTER NAME

RELEASE/CHANGED

004101

MSC I UNSUCC DUE A IF CRC

S5

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover because noradio resources are available due to switch_crc_pool, target BSC

EXPLANATION Number of incoming unsuccessful HOs due to a wrong A interfacecircuit type.

UPDATED When the HO attempt ends as a result of a TCH allocation attemptwhich is unsuccessful because of a mismatch between therequested TCH channel type and the A interface circuit type. Thecause switch_circuit_pool is sent in the HANDOVER_FAILUREmessage to the A interface.


IMPACT HO failure


No

COUNTER NAME

RELEASE/CHANGED

004102

MSC O UNSUCC DUE A IF CRC

S5

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover becausethe MSC rejects the handover due to various causes, source BSC

EXPLANATION Number of HOs that are unsuccessful because of a wrong Ainterface circuit type.

UPDATED When an external HO attempt ends with the A interface causescircuit_pool_mismatch or switch_ circuit_pool.

This counter is updated also when a HO attempt initiated by the BSCis interrupted because there is no proper circuit pool or there is nofree A interface circuit available in the proper pool.


IMPACT HO failure




No

COUNTER NAME

RELEASE/CHANGED

004103

HO FROM NORMAL TO EXT AREA

S6

EXPLANATION Number of HOs from normal area to extended area.

UPDATED When internal intra-cell HO start reason is cause DISTANCE (4027)and the HO is attempted from normal area to extended area.

RELATED TO A FEATURE BSS6037: Improved Solution for Extended Cell

No

COUNTER NAME

RELEASE/CHANGED

004104

HO FROM EXT TO NORMAL AREA

S6

EXPLANATION Number of HOs from extended area to normal area.

UPDATED When internal intra-cell HO is started as a result of the causeLOW_DISTANCE (4088) and the HO attempt is from extended areato normal area.

RELATED TO A FEATURE BSS6037: Improved Solution for Extended Cell

No

COUNTER NAME

RELEASE/CHANGED

004105

HO DUE TO MS SLOW SPEED

S6






EXPLANATION HO due to a detected low speed MS.

UPDATED When an internal inter-cell or external HO attempt is started becausethe speed of the MS is below the threshold value LSL (Lower SpeedLimit).

RELATED TO A FEATURE BSS6083: MS Speed Detection



No

COUNTER NAME

RELEASE/CHANGED

004106

HO DUE TO MS HIGH SPEED

S6






EXPLANATION HO due to a detected high speed MS.

UPDATED When an internal inter-cell or external HO attempt is started becausethe speed of the MS has exceeded the threshold value USL (UpperSpeed Limit).

RELATED TO A FEATURE BSS6083: MS Speed Detection

No

COUNTER NAME

RELEASE/CHANGED

004107

MSC O CALL DROP DURING HO

S7

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover due to GSMtimer T8 expiry, source BSC

EXPLANATION Number of calls that are dropped during external HOs, after theHANDOVER_COMMAND is received from the MSC.

UPDATED a) When a call is dropped during an external HO and after the BSChas received a HANDOVER_COMMAND message.

b) When either the GSM timer T8 expires, or the MSC sends aCLEAR_COMMAND message to the BSC with other cause than callcontrol or handover successful.


RELATED TO A FEATURE BSS7042 Measurement improvements

IMPACT Call cleared



No

COUNTER NAME

RELEASE/CHANGED

004108

MSC I CALL POSS DROP DURING HO

S7

TRIGGER POINT(S) See figure Unsuccessful external TCH to TCH handover, target BSC

EXPLANATION Number of failures (the call may possibly be dropped) duringexternal HOs, after the HO_REQUEST_ ACK message is sent to theMSC.

UPDATED a) When a call is possibly dropped during an external HO, after theHO_REQUEST_ACK message is sent to the MSC.

b) When the GSM timer T9113 expires or the MSC sends aCLEAR_COMMAND message to the BSC with some other causethan call control or radio interface failure revision to old channel.


RELATED TO A FEATURE BSS7042 Measurement improvements

IMPACT Possibly call cleared

No

COUNTER NAME

RELEASE/CHANGED

004109

HO ATT DUE TO BAD RXLEV ON SUPER

S7

TRIGGER POINT(S) See figure Successful internal intra-cell TCH to TCH handover

EXPLANATION Number of HO attempts due to a Bad Rxlevel on a super-reusefrequency.

UPDATED When a HO is started due to a Bad Rxlevel on the super-reusefrequency.

RELATED TO A FEATURE BSS7064 ICE handover support



No

COUNTER NAME

RELEASE/CHANGED

004110

HO ATT DUE TO GOOD RXLEV ON REGULAR

S7


EXPLANATION Number of HO attempts due to a Good Rxlevel on a regularfrequency.

UPDATED When a HO is started due to a Good Rxlevel on the regularfrequency.

RELATED TO A FEATURE BSS7064 ICE handover support

No

COUNTER NAME

RELEASE/CHANGED

004111

HO ATT DUE ERFD

S7






EXPLANATION Number of inter-cell HO attempts during an ERFD (Enhanced RapidField Drop) HO. All inter-cell HOs during ERFD HO are mapped tothe ERFD HO counter.

UPDATED When a HO is started due to ERFD.

RELATED TO A FEATURE BSS7031 Rapid field drop improvement

No

COUNTER NAME

RELEASE/CHANGED

004112

MSC O ATT FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful external TCH TCH HSCSD handover fromtwo to two channels, source BSC

EXPLANATION Number of outgoing HO attempts for HSCSD calls controlled by theMSC.



UPDATED When a HO attempt for HSCSD connection is started.

DEPENDENCIES Counter 004052 or 004053 will also be updated.

RELATED TO A FEATURE BSS7003, BSS7037 HSCSD and 14.4 kbit/s data services

No

COUNTER NAME

RELEASE/CHANGED

004112

MSC O ATT FOR HSCSD

S7

No

COUNTER NAME

RELEASE/CHANGED

004113

MSC O SUCC FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful external TCH TCH HSCSD handover fromtwo to two channels, source BSC

EXPLANATION Number of successful outgoing HOs for HSCSD calls controlled bythe MSC.

UPDATED When a HO attempt for HSCSD connection is completed.

DEPENDENCIES Counter 004049 or 004050 and counter 004004 will also be updated.


No

COUNTER NAME

RELEASE/CHANGED

004114

MSC I ATT FOR HSCSD

S7




EXPLANATION Number of incoming HO attempts for HSCSD calls controlled by theMSC.

UPDATED When a HO attempt for a multichannel connection is started.





No

COUNTER NAME

RELEASE/CHANGED

004115

MSC I SUCC FOR HSCSD

S7




EXPLANATION Number of successful incoming HOs for HSCSD calls controlled bythe MSC.

UPDATED When a HO attempt for a multichannel connection is completed.



No

COUNTER NAME

RELEASE/CHANGED

004116

MSC I SUCC INC FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful external TCH TCH HSCSD handover fromone to two channels, target BSC

EXPLANATION The number of channels in an MSC-controlled HO for an outgoingHSCSD call has increased.

UPDATED When a current channel IE is included in theHANDOVER_REQUEST message and the number of allocatedchannels is greater in the target cell than in the source cell.




No

COUNTER NAME

RELEASE/CHANGED

004117

MSC I SUCC DEC FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful external TCH TCH HSCSD handover fromfour to one channel, target BSC

EXPLANATION The number of channels in an MSC-controlled HO for an outgoingHSCSD call has decreased.

UPDATED When a current channel IE is included in theHANDOVER_REQUEST message and the number of allocatedchannels in the target cell is lower than in the source cell.


No

COUNTER NAME

RELEASE/CHANGED

004118

BSC O ATT FOR HSCSD

S7




EXPLANATION Number of outgoing HO attempts for HSCSD calls controlled by theBSC.






No

COUNTER NAME

RELEASE/CHANGED

004119

BSC O SUCC FOR HSCSD

S7




EXPLANATION Number of successful outgoing HOs for HSCSD calls controlled bythe BSC.

UPDATED When a HO attempt for multichannel connection is completed.



No

COUNTER NAME

RELEASE/CHANGED

004120

BSC I ATT FOR HSCSD

S7




EXPLANATION Number of incoming HO attempts for HSCSD calls controlled by theBSC.






No

COUNTER NAME

RELEASE/CHANGED

004121

BSC I SUCC FOR HSCSD

S7




EXPLANATION Number of successful incoming HOs for HSCSD calls controlled bythe BSC.

UPDATED When a HO attempt for a multichannel connection is completed.



No

COUNTER NAME

RELEASE/CHANGED

004122

BSC I SUCC INC FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful internal inter-cell TCH TCH HSCSD handoverfrom two to three channels

EXPLANATION The number of channels in an BSC-controlled HO for an outgoingHSCSD call has increased.

UPDATED When a number of allocated channels in the target cell is greaterthan in the source cell.


No

COUNTER NAME

RELEASE/CHANGED

004123

BSC I SUCC deC FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful internal inter-cell TCH TCH HSCSD handoverfrom three to one channel



EXPLANATION The number of channels in an BSC-controlled HO for an outgoingHSCSD call has decreased.

UPDATED When a number of allocated channels in the target cell is lower thanin the source cell.


No

COUNTER NAME

RELEASE/CHANGED

004123

BSC I SUCC deC FOR HSCSD

S7

No

COUNTER NAME

RELEASE/CHANGED

004124

INTRA ATT FOR HSCSD

S7




EXPLANATION Number of intra-cell HO attempts for HSCSD calls.

UPDATED When a HO attempt for multichannel connection is started.



No

COUNTER NAME

RELEASE/CHANGED

004125

INTRA SUCC FOR HSCSD

S7




EXPLANATION Number of successful intra-cell HOs for HSCSD calls.

UPDATED When a HO attempt for multichannel connection is completed.





No

COUNTER NAME

RELEASE/CHANGED

004126

INTRA SUCC INC FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful internal intra-cell TCH TCH HSCSD handoverfrom one to three channels

EXPLANATION The number of channels in intra-cell HOs for an HSCSD call hasincreased .

UPDATED When the number of allocated channels in the target TRX is greaterthan in the source TRX.


No

COUNTER NAME

RELEASE/CHANGED

004127

INTRA SUCC DEC FOR HSCSD

S7

TRIGGER POINT(S) See figure Successful internal intra-cell TCH TCH HSCSD handoverfrom two to one channel

EXPLANATION The number of channels in intra-cell HOs for a HSCSD call hasdecreased.

UPDATED When a number of allocated channels in the target TRX is lowerthan in the source TRX.




No

COUNTER NAME

RELEASE/CHANGED

004128

HO ATT DUE TO DIRECT ACCESS

S7




EXPLANATION Number of direct access attempts.

In the HO measurement, an intra-cell direct access is considered anintra-cell HO and correspondingly, an inter-cell direct access isconsidered an inter-cell HO.

UPDATED When a HO is started with cause direct access

RELATED TO A FEATURE BSS7057 Direct access to super reuse TRX in IUO

No

COUNTER NAME

RELEASE/CHANGED

004129

HO ATT DUE TO DADLB

S8

TRIGGER POINT(S) See figure Handover attempt due to DADL/B

EXPLANATION This counter is updated when a handover attempt is started due toDirect Access to Desired Layer/Band (DADL/B).

UPDATED When a HO is started with cause DADL/B.

RELATED TO A FEATURE BSS8032 Direct Access to Desired Layer/Band



No

COUNTER NAME

RELEASE/CHANGED

004130

HO ATT DUE TO GPRS

S9


EXPLANATION This counter is updated when a handover attempt is started due toGPRS channel allocation.

UPDATED When a HO is started with the request of the radio resourcemanager in order to enable an upgrade to the GPRS territory.

NOTE! This counter may show some values even if there has beenno GPRS Traffic. Since the GPRS Territory method operatesaccording to CS Traffic, this may cause upgrades and downgrades tothe GPRS Territory and subsequently cause handovers to CS Callstriggering this counter.

RELATED TO A FEATURE BSS9006 GPRS Telecom in BCSU and MCMU

No

COUNTER NAME

RELEASE/CHANGED

004131

INTRA CELL SUCCESS SDCCH HO BETWEEN BTSS

S10

EXPLANATION Number of completed and successful SDCCH-SDCCH handoversbetween two BTSs of the segment.

UPDATED At the target BTS when the call has been successfully transferred tothe target SDCCH.

RELATED TO A FEATURE BSS10016 Common BCCH Control

BSS10046 Multi BCF Control

No

COUNTER NAME

RELEASE/CHANGED

004132

INTRA CELL SUCCESS TCH HO BETWEEN BTSS

S10

EXPLANATION Number of completed and successful TCH to TCH handoversbetween the BTSs of the segment.

UPDATED At the target BTS when the call has been successfully transferred tothe target TCH.


BSS10046 Multi BCF Control



No

COUNTER NAME

RELEASE/CHANGED

004133

HO ATTEMPT INTER BAND SDCCH

S10

EXPLANATION Number of attempts to perform an SDCCH-SDCCH handover, basedon the duration of an SDCCH reservation, from a BTS on the BCCHfrequency band to a BTS on another frequency band of the segment.

UPDATED At the source BTS on BCCH frequency band whenever a handoverattempt is made to move a call to an SDCCH on another frequencyband of the segment. PGSM 900 and EGSM 900 are here regardedas different bands.

DEPENDENCIES Information on the success of the attempts can be seen on BSClevel in counter 051136.


No

COUNTER NAME

RELEASE/CHANGED

004134

INTRA CELL SUCCESS SDCCH HO BETWEEN BANDS

S10

EXPLANATION Number of completed and successful SDCCH-SDCCH handoversbetween two BTSs on different frequency bands of a segment.PGSM 900 and EGSM 900 are regarded as parts of the same GSM900 frequency band.






No

COUNTER NAME

RELEASE/CHANGED

004135

HO ATTEMPT INTER BAND TCH

S10

EXPLANATION Number of attempts to perform a TCH to TCH handover betweenBTSs on different frequency bands of a segment due to load.

UPDATED At the source BTS whenever a handover is initiated in order to movea call to another band of the segment and, as a result, to decreasethe load of the source BTS. PGSM 900 and EGSM 900 are regardedhere as different bands.

DEPENDENCIES Information on the success of the attempts can be seen on BSClevel in counter 051135.


No

COUNTER NAME

RELEASE/CHANGED

004136

INTRA CELL SUCCESS TCH HO BETWEEN BANDS

S10

EXPLANATION Number of completed and successful TCH to TCH handoversbetween two BTSs on different frequency bands of a segment.PGSM 900 and EGSM 900 are regarded as parts of the same GSM900 frequency band.

UPDATED At the target BTS when the call has been successfully transferred tothe target TCH between GSM 900 and GSM 1800 bands in eitherdirection.





No

COUNTER NAME

RELEASE/CHANGED

004137

HO ATTEMPT INTER BTS TYPE SDCCH

S10

EXPLANATION Number of attempts to perform an SDCCH to SDCCH handover,based on the duration of an SDCCH reservation, from an UltraSiteBTS to a Talk Family BTS within a segment.

UPDATED At the source BTS whenever an attempt is made to move a call froman SDCCH in an UltraSite BTS to an SDCCH in a Talk Family BTS ofthe segment, based on the duration of the source SDCCHreservation.

DEPENDENCIES Information on the success of the attempts on BSC level can beseen in counter 051148.

RELATED TO A FEATURE BSS10046 Multi BCF Control

No

COUNTER NAME

RELEASE/CHANGED

004138

INTRA CELL SUCCESS SDCCH HO BETWEEN BTSTYPES

S10

EXPLANATION Number of completed and successful SDCCH to SDCCH handoversfrom a BTS of one base station site type to a BTS of another typewithin a segment.

UPDATED At the target BTS when the call has been successfully transferred tothe target SDCCH and the handover was between BTSs of differentbase station site types within a segment.





No

COUNTER NAME

RELEASE/CHANGED

004139

HO ATTEMPT INTER BTS TYPE TCH

S10

EXPLANATION Number of attempts to perform a TCH to TCH handover betweendifferent BTS types due to load reasons within a segment.

UPDATED At the source BTS whenever an attempt is made to move a callbetween different BTS types in order to decrease the load of thesource BTS.

DEPENDENCIES Information on the success of the attempts on BSC level can beseen in counter 051147.


No

COUNTER NAME

RELEASE/CHANGED

004140

INTRA CELL SUCCESS TCH HO BETWEEN BTS TYPES

S10

EXPLANATION Number of completed and successful TCH to TCH handovers from aBTS of one base station site type to a BTS of another type within asegment.

UPDATED At the target BTS when the call has been successfully transferred tothe target TCH and the handover was between BTSs of differentbase station site types within a segment.



No

COUNTER NAME

RELEASE/CHANGED

004141

HO ATT DUE TO HSCSD

S10

EXPLANATION Number of intra cell handover attempts that are made due to theHSCSD traffic.

UPDATED When an intra cell handover attempt is initiated for a single slot call inorder to enable an upgrade for an GSCSD call.

RELATED TO A FEATURE BSS7003 High Speed Circuit-Switched Data



No

COUNTER NAME

RELEASE/CHANGED

004142

HO ATT FOR AMR TO HR

S10

EXPLANATION Number of HO attempts from AMR FR to AMR HR.

UPDATED When a channel rate change HO attempt for AMR FR call is started.

RELATED TO A FEATURE BSS10004 Adaptive Multi Rate Codec

No

COUNTER NAME

RELEASE/CHANGED

004143

HO ATT FOR AMR TO FR

S10

EXPLANATION Number of HO attempts from AMR HR to AMR FR.

UPDATED When a channel rate change HO attempt for AMR HR call is started.

RELATED TO A FEATURE BSS10004 Adaptive Multi Rate Codec

No

COUNTER NAME

RELEASE/CHANGED

004144

MSC I TCH HO FROM WCDMA RAN ATTEMPT

S10.5

EXPLANATION Number of incoming (WCDMA RAN to GSM) inter-system handoverattempts.

UPDATED When the HO attempt from WCDMA RAN to GSM is started.

RELATED TO A FEATURE GSM-WCDMA Inter-System Handover

No

COUNTER NAME

RELEASE/CHANGED

004145

MSC I WCDMA RAN HO ATTEMPT UNSUCC DUE LACK

S10.5

EXPLANATION Number of incoming (WCDMA RAN to GSM) handover requestsrejected by the BSC due to lack of resources.

UPDATED No channel is available for a HO and HANDOVER_FAILUREmessage is sent to the MSC when WCDMA RAN to GSM handoverhas been requested.




No

COUNTER NAME

RELEASE/CHANGED

004146

MSC I WCDMA RAN HO ATTEMPT UNSUCC DUE BSSPROBLEM

S10.5

EXPLANATION Number of incoming (WCDMA RAN to GSM) handovers which areunsuccessful due to BSS problems.

UPDATED Radio channel activation fails and HANDOVER_FAILURE messageis sent to the MSC when WCDMA RAN to GSM handover has beenrequested.


No

COUNTER NAME

RELEASE/CHANGED

004147

MSC I WCDMA RAN END OF HO

S10.5

EXPLANATION Number of the end of inter-system handover procedures in incoming(WCDMA RAN to GSM) HOs.

UPDATED When the call is cleared during the HO by a message received fromthe MSC concerning resetting the circuits or the BSCU restart (if theTCHs related to the HO are in that BCSU).

This may occur in the following situations:

• MS returns to the source channel

• MS is lost during the HO

• Call is cleared during the HO either by the subscriber or bymessages from the MS concerning

-the start of channel blocking

-the A interface speech circuits


-abnormal release of the SCCP connection




No

COUNTER NAME

RELEASE/CHANGED

004148

MSC I UNSUCCESS HO WCDMA RAN DUE CONN

S10.5

EXPLANATION Number of incoming (WCDMA RAN to GSM) Inter-System HOswhich are unsuccessful due to a connection failure.

UPDATED When the connection between the MS and the BTS is broken (on thetarget channel), that is, when a message carrying an indication of aconnection failure is received (radio link failure or transcoder failure).


No

COUNTER NAME

RELEASE/CHANGED

004149

MSC I HO WCDMA RAN TCH SUCCESS

S10.5

EXPLANATION Number of successfully completed incoming (WCDMA RAN to GSM)handovers.

UPDATED When the inter-system handover (WCDMA RAN to GSM) isacknowledged and completed i.e. theHANDOVER_REQUEST_ACKNOWLEDGE and theHANDOVER_COMPLETED messages are sent to the MSC.


No

COUNTER NAME

RELEASE/CHANGED

004150

MSC O TCH HO TO WCDMA RAN ATTEMPT

S10.5

EXPLANATION Number of outgoing (GSM to WCDMA RAN) HO attempts controlledby the MSC. Signal strength (Ec/No) and the load of the serving GSMcell are above the thresholds.

UPDATED The HANDOVER_REQUIRED message is sent to the MSC and theHO attempt is started.




No

COUNTER NAME

RELEASE/CHANGED

004151

MSC O HO TO WCDMA RAN NOT ALLOWED

S10.5

EXPLANATION Number of outgoing (GSM to WCDMA RAN) inter-system HOscontrolled by the MSC which are unsuccessful because Hos are notallowed.

UPDATED The BSC does not send the HANDOVER_REQUIRED message tothe MSC.

When it is not allowed to execute an inter-system HO in the currentphase of the call in progress.


No

COUNTER NAME

RELEASE/CHANGED

004152

MSC O END OF HO TO WCDMA RAN DUE BSS

S10.5

EXPLANATION Number of the end of outgoing (GSM to WCDMA RAN) handoverprocedures due to BSS problems (outgoing HO controlled by theMSC).

UPDATED When the connection between the MS and the BTS is broken (on thesource channel), that is, when a message carrying an indication ofconnection failure is received (radio link failure or transcoder failure).

The counter is updated for

-non-transparent data calls

-transparent data calls

-speech calls




No

COUNTER NAME

RELEASE/CHANGED

004153

MSC O GEN INTER SYSTEM TO WCDMA RANHANDOVER REQ MESSAGES

S10.5

EXPLANATION Total number of HANDOVER_REQUIRED messages generated byoutgoing (GSM to WCDMA RAN) inter-system HOs controlled by theMSC.

UPDATED When the BSC sends the HANDOVER_REQUIRED message to theMSC.




-speech calls


No

COUNTER NAME

RELEASE/CHANGED

004154

MSC O GEN INTER SYSTEM TO WCDMA RANHANDOVER COM MESSAGES

S10.5

EXPLANATION Number of theINTER_SYSTEM_HANDOVER_TO_WCDMA_RAN_COMMANDmessages generated by outgoing (GSM to WCDMA RAN) inter-system HOs controlled by the MSC.

UPDATED When the HANDOVER COMMAND is sent to the MS




-speech calls




No

COUNTER NAME

RELEASE/CHANGED

004155

MSC O TO WCDMA RAN FAIL LACK

S10.5

EXPLANATION Number of outgoing (GSM to WCDMA RAN) inter-system HOscontrolled by the MSC which are unsuccessful due to no radioresources available in the target cell.

UPDATED The BSC has received the HANDOVER_REQUIRED_REJECTmessage from the MSC

-when no channel is available in the target cell for an HO

-when the GSM timer T7 expires.




-speech calls


No

COUNTER NAME

RELEASE/CHANGED

004156

MSC O END OF HO TO WCDMA RAN

S10.5

EXPLANATION Number of the end of handover procedures for outgoing (GSM toWCDMA RAN) HO controlled by the MSC.

UPDATED -When the GSM timer T3121 expires (CLEAR_COMMAND messagenot received).

-When the HO is rejected with cause differing from the causecip_type_mismatch, or invalid_cell, T7 expiry, no radio resourceavailable or no terrestrial channel available in the target cell.

-When the MSC sends a CLEAR_COMMAND message with anotherreason than handover successful or call control to the BSC.

- Internal conflict with the A interface.




-speech calls




No

COUNTER NAME

RELEASE/CHANGED

004157

MSC O CALL DROP DURING HO TO WCDMA RAN

S10.5

EXPLANATION Number of dropped calls during outgoing (GSM to WCDMA RAN)HOs after the HANDOVER COMMAND is received from the MSC.

UPDATED -When a call is dropped during an external HO after the BSC hasreceived a HANDOVER_COMMAND message. That is,

-When either the GSM timer T8 expires

-When the MSC sends a CLEAR_COMMAND message to the BSCwith other cause than call control or handover successful.




-speech calls


No

COUNTER NAME

RELEASE/CHANGED

004158

MSC O TO WCDMA RAN SUCCESS TCH HO

S10.5

EXPLANATION Number of successful outgoing (GSM to WCDMA RAN) HOscontrolled by the MSC.

UPDATED When the inter-system HO is completed and BSC has received theCLEAR_COMMAND from the MSC.




-speech calls




No

COUNTER NAME

RELEASE/CHANGED

004159

SUCCESSFUL HO INTER BAND TCH

S10.5

EXPLANATION Number of successful and completed TCH-TCH handovers betweenBTSs of different frequency bands of a segment due to load.


DEPENDENCIES WITHOTHER COUNTERS

Counter 004135 is updated in the source BTS of the handover.

RELATED TO A FEATURE BSS10016 PGSM900/EGSM900/GSM1800 Common BCCH,BSS10087 GSM/EDGE 800/1900 Common BCCH

No

COUNTER NAME

RELEASE/CHANGED

004160

SUCCESSFUL HO INTER BTS TYPE TCH

S10.5

EXPLANATION Number of successful and completed TCH-TCH handovers betweendifferent BTS types of a segment due to load.





No

COUNTER NAME

RELEASE/CHANGED

004161

UNSUCCESSFUL HO INTER BAND TCH

S10.5

EXPLANATION Number of unsuccessful TCH-TCH handovers between BTSs ofdifferent frequency bands of a segment due to load.

UPDATED At the source BTS.






No

COUNTER NAME

RELEASE/CHANGED

004162

UNSUCCESSFUL HO INTER BTS TYPE TCH

S10.5

EXPLANATION Number of unsuccessful TCH-TCH handovers between different BTStypes of a segment due to load.

UPDATED At the source BTS.




No

COUNTER NAME

RELEASE/CHANGED

004163

HO ATTEMPT INTER BAND DUE LEVEL

S10.5

EXPLANATION Number of attempts to perform a TCH-TCH handover from non-BCCH layer between BTSs on different frequency bands of asegment due to weak downlink signal level.

UPDATED At the source BTS whenever a handover is initiated to move a call toanother band of the segment due to weak downlink signal level.PGSM 900 and EGSM 900 are regarded here as different bands.


Success of the attempts can be seen on BSC level in counter 051135


No

COUNTER NAME

RELEASE/CHANGED

004164

UNSUCC HO INTER BAND DUE LEVEL

S10.5

EXPLANATION Number of unsuccessful attempts to perform a TCH-TCH handoverfrom non-BCCH layer between BTSs on different frequency bands ofa segment due to weak downlink signal level.



UPDATED At the source BTS when a handover to move a call to another bandof the segment due to weak downlink signal level fails. PGSM 900and EGSM 900 are regarded here as different bands.


Counter 004169 is updated in the source BTS.


No

COUNTER NAME

RELEASE/CHANGED

004164

UNSUCC HO INTER BAND DUE LEVEL

S10.5

No

COUNTER NAME

RELEASE/CHANGED

004165

SUCC HO INTER BAND DUE LEVEL

S10.5

EXPLANATION Number of successful attempts to perform a TCH-TCH handoverfrom non-BCCH layer between BTSs on different frequency bands ofa segment due to weak downlink signal level.

UPDATED At the target BTS when a handover to move a call to another band ofthe segment due to weak downlink signal level succeeds. PGSM 900and EGSM 900 are regarded here as different bands.


Counter 004169 is updated in the source BTS.


No

COUNTER NAME

RELEASE/CHANGED

004166

INTER SEGMENT SUCCESS SDCCH HO BETWEENBANDS

S10.5

EXPLANATION Number of completed and successful SDCCH-SDCCH handoversbetween two BTSs on different frequency bands between twosegments.





Counters 004058 and 004066 are updated along with this counter.


No

COUNTER NAME

RELEASE/CHANGED

004166

INTER SEGMENT SUCCESS SDCCH HO BETWEENBANDS

S10.5

No

COUNTER NAME

RELEASE/CHANGED

004167

INTER SEGMENT SUCCESS SDCCH HO BETWEEN BTSTYPES

S10.5

EXPLANATION Number of completed and successful SDCCH-SDCCH handoversbetween two different types of BTSs between two segments.





No

COUNTER NAME

RELEASE/CHANGED

004168

INTER SEGMENT SUCCESS TCH HO BETWEEN BANDS

S10.5

EXPLANATION Number of completed and successful TCH-TCH handovers betweentwo BTSs on different frequency bands between two segments.







No

COUNTER NAME

RELEASE/CHANGED

004169

INTER SEGMENT SUCCESS TCH HO BETWEEN BTSTYPES

S10.5

EXPLANATION Number of completed and successful TCH-TCH handovers betweentwo different types of BTSs between two segments.





No

COUNTER NAME

RELEASE/CHANGED

004170

SPARE004170

EXPLANATION Spare

No

COUNTER NAME

RELEASE/CHANGED

004171

SPARE004171

EXPLANATION Spare

No

COUNTER NAME

RELEASE/CHANGED

004172

SPARE004172

EXPLANATION Spare



Related topics



No

COUNTER NAME

RELEASE/CHANGED

004173

SPARE004173

EXPLANATION Spare



3 Signalling charts of HandoverMeasurement

The following figures show the signalling charts of Handover Measurement:



Figure 1. Successful internal intra-cell TCH to TCH handover.

Counter 4109 or 4110 is updated only in case of a handover attempt due to a badRxlevel on a super-reuse frequency or a good Rxlevel on a regular frequency.

BTS: MSC: MS: BSC:

Cause downlink qualityCause distanceCause high int on uplinkCause high int on downlinkCause ho started by omcCause preemptionCause low distanceCause bad ci ratioCause good ci ratioHo att due bad rxlev on superHo att due good rxlev on reg

Int cell success ho

Cell tch tch

Cell tch tch attempt

Meas report Meas result

Physical context request

Physical context confirm

Channel activation

Channel activation ack

Assignment command

Assignment command

Sabm Establish indication

Ua

RrHO performed

Rf channel release

Rf channel release ack

Assignment completeAssignment complete

Ho att due to GPRS

HO measurement, HO decision --> intra-cell HO attempt, old channel

4025 or4027 or4029 or4030 or4033 or4086 or4088 or4089 or4090 or4109 or4110 or

4076

4130

New channel reservation and activation

Signalling on old channel

Signalling on new channel

Old channel release

4018

4073



Figure 2. Successful internal inter-cell TCH to TCH handover.

BTS_1:MS: MSC:BTS_2: BSC:

HO performed

Rf channel release


HO commandHO command

Channel activation

HO detectionPhysical info

HO access

Establish indicationUa

HO complete HO completeRr

Sabm

HO measurements, old channel in the old BTS

Cause uplink qualityCause uplink levelCause downlink qualityCause downlink levelCause distanceCause resp to msc invocatCause high int on uplinkCause high int on downlinkCause umbrella hoCause power bugdet hoCause ho started by omcCause preemptionCause field dropCause low distanceCause bad ci ratioCause good ci ratioHo due slow mov msHo due to ms slow speedHo due to ms high speed

4023 or4024 or4025 or4026 or4027 or4028 or4029 or4030 or4031 or4032 or4033 or4086 or4087 or4088 or4089 or4090 or4091 or4105 or4106 or

Bsc o nonopt at

Bsc i nonopt at

Bsc i tch tch at

Bsc o tch tch at

4071

4063

4059

4067

Ho att due erfd 4111


Old channel release in the old BTS

Bsc i nonopt

Bsc i tch tch

Bsc i success ho

Bsc o nonopt

Bsc o tch tch

Bsc o success ho

4062

4056

4010

4070

4064

4014

Signalling on the new channel in the new BTS

New channel reservation and activation in the new BTS

Signalling on the old channel in the old BTS




Counters 4067, 4071, 4014, 4064, 4070 and cause counters are updated in thesource cell. Counters 4059, 4063, 4010, 4056 and 4062 are updated in the targetcell. If the handover is made from normal to extended area, instead of counter4027, counter 4103 is updated. If the handover is made from extended to normalarea, instead of counter 4088, counter 4104 is updated. Counters 4063, 4071,4070 and 4062 are updated only if the target cell is non-optimum.



Figure 3. Successful external TCH to TCH handover, source BSC.

If the handover is made from normal to extended area, instead of counter 4027,counter 4103 is updated. If the handover is made from extended to normal area,instead of counter 4088, counter 4104 is updated. Counter 4095 is updated onlyif cause counter 4099 is updated.

BTS: MSC: MS: BSC:

Msc o succ switch circ pool

Msc o succ tch tch ho

Msc o succ ho

Msc o gen ho com msg

Msc o gen ho req msg

Msc o tch tch at

Cause uplink qualityCause uplink levelCause downlink qualityCause downlink levelCause distanceCause resp to msc invocatCause high int on uplinkCause high int on downlinkCause umbrella hoCause power bugdet hoCause ho started by omcCause preemptionCause field dropCause low distanceHo due slow mov msHo att due switch circ poolHo due to ms slow speedHo due to ms high speedHo att due erfd

HO command

Rf channel release


HO required


Clear complete


Clear command

HO measurements, HO decision --> external HO attempt

Channel reservation and activation in new (target) BSC, HO command from MSC

4052

4023 or4024 or4025 or4026 or4027 or4028 or4029 or4030 or4031 or4032 or4033 or4086 or4087 or4088 or4091 or4099 or4105 or4106 or4111

4009

4005

Old channel release in the old BSC

4095

4049

4004



Figure 4. Successful external TCH to TCH handover, target BSC.

Counter 4093 can be updated only if counter 4092 is updated.

BSC:

Msc i succ ho

Msc i succ switch circ pool

Msc i succ tch tch ho

Msc i att switch circ pool

Msc i tch tch ho att

MS: MSC:BTS:

HO request

Channel activation


HO request ack

HO accessHO detection HO detection

Physical info

SabmEstablish indication

Ua

HO complete

Rr

HO complete

HO completed

4000

4093

4043

Signalling on the new BTS, connection

HO measurements and external HO decision done in source BSC, MSC sends HO request

Channel reservation and activation in the new BTS

4092

4046



Figure 5. Successful internal intra-cell SDCCH to SDCCH handover.

MS: BTS: BSC: MSC:


Cell sdcch attempt

Cause downlink qualityCause distanceCause high int on uplinkCause high int on downlinkCause ho started by omcCause preemptionCause low distanceCause bad ci ratioCause good ci ratio



Channel activation


Assignment command

Assignment command


Ua

Assignment complete

Assignment complete

RrHO performed

Cell sdcch

Int cell success ho

Rf channel release






Old channel release

4078

4025 or4027 or4029 or4030 or4033 or4086 or4088 or4089 or4090 or

4075

4018



Figure 6. Successful internal inter-cell SDCCH to SDCCH handover.

MS: BTS_1: BTS_2: BSC: MSC:


Bsc o sdcch at

Bsc i sdcch at

Bsc i nonopt at

Bsc o nonopt at

Channel activation


HO command HO command

HO access HO detectionPhysical info

Sabm Establish indicationUa

HO complete HO completeRr HO performed

Bsc o success ho

Bsc o sdcch

Bsc o nonopt

Bsc i success ho

Bsc i sdcch

Bsc i nonopt

Rf channel releaseRf channel release ack






4069

4061

4063

4071

4014

4066

4070

4010

4058

4062

Cause uplink qualityCause uplink levelCause downlink qualityCause downlink qualityCause distanceCause resp to msc invocatCause high int on uplinkCause high int on downlinkCause umbrella hoCause power bugdet hoCause ho started by omcCause preemptionCause field dropCause low distanceCause bad ci ratioCause good ci ratioHo due slow mov msHo due to ms slow speedHo due to ms high speedHo att due erfd

4023 or4024 or4025 or4026 or4027 or4028 or4029 or4030 or4031 or4032 or4033 or4086 or4087 or4088 or4089 or4090 or4091 or4105 or4106 or4111



Counters 4069, 4071, 4014, 4066, 4070 and cause counters are updated in thesource cell. Counters 4061, 4063, 4010, 4058 and 4062 are updated in the targetcell. If the handover is made from normal to extended area, instead of counter4027, counter 4103 is updated. If the handover is made from extended to normalarea, instead of counter 4088, counter 4104 is updated. Counters 4063, 4071,4070 and 4062 are updated only if the target cell is non-optimum.



Figure 7. Successful external SDCCH to SDCCH handover, source BSC.

If the handover is made from normal to extended area, instead of counter 4027,counter 4103 is updated. If the handover is made from extended to normal area,instead of counter 4088, counter 4104 is updated. Counter 4095 is updated onlyif cause counter 4099 is updated.

BTS: MSC: MS: BSC:

Msc o sdcch

Msc o succ ho



Msc o sdcch at

HO command

Rf channel release


HO required


Clear complete


Clear command


Cause uplink qualityCause uplink levelCause downlink qualityCause downlink qualityCause distanceCause resp to msc invocatCause high int on uplinkCause high int on downlinkCause umbrella hoCause power bugdet hoCause ho started by omcCause preemptionCause field dropCause low distanceHo due slow mov msHo att due switch circ poolHo due to ms slow speedHo due to ms high speedHo att due erfd

4023 or4024 or4025 or4026 or4027 or4028 or4029 or4030 or4031 or4032 or4033 or4086 or4087 or4088 or4091 or4099 or4105 or4106 or4111

4054


4051

4004

4009

4005


Msc o succ switch circ pool 4095



Figure 8. Successful external SDCCH to SDCCH handover, target BSC.

Counter 4093 is updated only if counter 4092 is updated.

BSC:

Msc i succ ho

Msc i succ switch circ pool

Msc i sdcch


Msc i sdcch att

MS: MSC:BTS:

HO request

Channel activation


HO request ack


Physical info


Ua

HO complete

Rr

HO complete

HO completed




4000

4093

4045

4092

4048



Figure 9. Internal intra-cell directed retry including feature BSS6114: TCHassignment to the super-reuse TRX in IUO.

BSC:

Int cell success ho

Cell sdcch tch

Cause dir retry

Cell sdcch tch at

MS: MSC:BTS:

Assignment requestPhysical context request


Channel activation



Assignment commandAssignment command

Ua

Rr Assignment complete

Rf channel release


Assignment complete Assignment complete

Queueing indication

Alert Alert

Connect ackConnect ack

Connect Connect



Paging part

Radio access part (on CCCH)

DDCH establishment part

SDCCH signalling part

Cell is congested, no TCH, DR HO begins

Queueing possible and started

Signalling on FACCH - TCH

Signalling on SDCCH

TCH reservation and activation

Physical context information

SDCCH release

Connection

Conversation phase

4018

4074

4079

4077



Figure 10. Internal inter-cell directed retry, including feature BSS6114 TCHassignment to the super-reuse TRX in IUO.

Counters 4063, 4071, 4070 and 4062 are updated only if the target cell is non-optimum.

BSC:

Bsc i nonopt

Bsc i sdcch tch

Bsc i success ho

Bsc o nonopt

Bsc o sdcch tch

Bsc o success ho

Bsc o nonopt at

Bsc i nonopt at

Bsc i sdcch tch at

Cause dir retry

Bsc o sdcch tch at

MS: MSC:BTS:



Channel activation




HO access HO detectionPhysical info

Ua



HO complete HO complete

Queueing indication

Alert Alert

Connect ackConnect ackConnect Connect

Paging partRadio access part (on CCCH)

DDCH establishment partSDCCH signalling part

Connection

Cell is congested, no TCH, DR HO beginsQueueing possible and started

TCH reservation and activation in new BTS

Signalling on SDCCH in old BTS

Signalling on FACCH - TCH in new BTS

SDCCH release in old BTS

Conversation phase

4062

4057

4010

4070

4065

4014

4071

4063

4060

4079

4068



Figure 11. External directed retry, source BSC.

BSC:


Msc o sdcch tch

Msc o succ ho


Cause dir retry

Msc o sdcch tch at

MS: MSC:BTS:


HO command

Clear command

Clear complete



Rf channel release


Queueing indication

Ho required

Paging part

Radio access part (on CCCH)

DDCH establishment part

Cell is congested, no TCH, DR HO begins

Queueing possible and started

SDCCH signalling part

TCH reservation and activation in target BSC

HO command from MSC, signalling on SDCCH

Signalling on FACCH - TCH on target BSC

SDCCH release in source BSC

4009

4050

4004

4005

4079

4053



Figure 12. External directed retry, target BSC.

BSC:

Msc i succ ho

Msc i sdcch tch

Msc i sdcch tch ho att

MS: MSC:BTS:

HO request

Channel activation


HO request ack


Physical info


Ua

HO complete

Rr

HO complete

HO completed

Alert Alert

Connect Connect


External DR start done in initial BSC, MSC sends ho request



4000

4044

4047

Conversation phase



Figure 13. Unsuccessful internal intra-cell TCH to TCH handover due to a lackof resources.

BTS: MSC: MS: BSC:

Int cell unsucc ho due lack 4019

Meas report

Meas result




Normal HO counters updated, see figure 1



HO ends and signalling continues on old channel

No free channel available



Figure 14. Unsuccessful internal inter-cell TCH to TCH handover due to a lackof resources.

Counters 4071 and 4072 are updated in the source cell. Counters 4063 and 4011are updated in the target cell. Counters 4063 and 4071 are updated only if thetarget cell is non-optimum.


Bsc o nonopt at

Bsc o fail lack

Bsc i unsucc ho due lack

Bsc i nonopt at

Meas report

Meas result

HO measurements, HO decision --> Internal inter-cell HO, old channel in old BTS



No free channel available

HO ends and signalling continues in the old channel

4071

4072

4011

4063



Figure 15. Unsuccessful external TCH to TCH handover due to a lack ofresources, source BSC.

BTS: MSC: MS: BSC:


Msc o fail lack

HO required reject

HO required

Meas report

Meas result



Unsuccessful channel reservation in new (target) BSC due lack of resources

HO ends and signalling continuous in the old channel

4005

4055



Figure 16. Unsuccessful external TCH to TCH handover due to a lack ofresources, target BSC.

BSC:

Msc i unsucc ho due lack


MS: MSC:BTS:

HO request

HO failure



No free channel

HO ends and signalling continuous on the old channel in the old BSC

4001

4046



Figure 17. Unsuccessful internal intra-cell TCH to TCH handover because ahandover is not allowed at this phase of the call.

BTS: MSC: MS: BSC:

Int cell ho not allowed

Meas report

Meas result



Channel activation


Rf channel release





Signalling on old channel, HO not allowed at this phase of call


Signalling continuous on old channel

4036



Figure 18. Unsuccessful internal inter-cell TCH to TCH handover because ahandover is not allowed at this phase of the call.

Counter 4038 is updated in the source cell. Counter 4081 is updated in the targetcell.


Bsc o ho not allowed

Bsc i end of ho

Rf channel release


Meas report

Meas result

Channel activation





Signalling on the old channel in the old BTS, HO not allowed


Signalling continuous on the old channel

4038

4081



Figure 19. Unsuccessful external TCH to TCH handover because a handoveris not allowed, source BSC.

BTS: MSC: MS: BSC:

Msc o ho not allowed

Meas report

Meas result



HO not allowed


4037



Figure 20. Unsuccessful internal intra-cell TCH to TCH handover due to afailure in the activation of a new channel.

BTS: MSC: MS: BSC:

Int cell unsucc ho due bss probl 4021

Meas report

Meas result



Channel activation

Channel activation nack

Rf channel release






Channel activation fails



Figure 21. Unsuccessful internal inter-cell TCH to TCH handover due to afailure in the activation of a new channel.



Bsc o end of ho

Bsc i unsucc ho due bss probl

Meas reportMeas result





Signalling continuous on the old channel

Rf channel release


Channel activation


4016

4013



Figure 22. Unsuccessful external TCH to TCH handover due to a failure in theactivation of a new channel, target BSC.

BSC:



Msc i unsucc ho due bss probl

MS: MSC:BTS:

HO request

HO failure

Channel activation


Rf channel release





HO ends and signalling continuous on the old channel in the old BSC

4092

4046

4003



Figure 23. Unsuccessful internal intra-cell TCH to TCH handover due to losingthe MS during handover. The GSM timer T3107 expires.

BTS: MSC: MS: BSC:

Cell drop calls

Int cell unsucc ho due move

Timer T3107 expires

Start timer T3107

Meas report

Meas result



Channel activation


Assignment command

Assignment command

Rf channel release


Rf channel release





MS is lost, Timer T3107 Expires

4085

4020

New channel release

Old channel release




Figure 24. Unsuccessful internal inter-cell TCH to TCH handover due to losingthe MS during handover. The GSM timer T3103 expires.

Counters 4016 and 4084 are updated in the source cell. Counters 4012 and 4083are updated in the target cell. Signalling can also be partly missing, depending onwhere the failure takes place.


Timer T3103 expires

Start timer T3103

Bsc i drop calls

Bsc i unsucc ho due conn

Bsc o drop calls

Bsc o end of ho

Rf channel release


Meas report

Meas result

HO command

HO command

Channel activation


HO detection

Physical info

HO access

Rf channel release







4083

4012

4084

4016

New channel release




Figure 25. Unsuccessful internal intra-cell TCH to TCH handover due to MSreturning to the old channel.

Signalling can be also partly missing, depending on where the failure happens.

BTS: MSC: MS: BSC:

Int cell unsucc ho due return 4022

Meas report

Meas result



Channel activation


Assignment command

Assignment command

Sabm

Establish indication

Ua

Rr

Rf channel release


Assignment failureAssignment failure







New channel release



Figure 26. Unsuccessful internal inter-cell TCH to TCH handover due to MSreturning to the old channel.

Counter 4015 is updated in the source cell. Counter 4012 is updated in the targetcell. Signalling can be also partly missing, depending on where the failure takesplace.


Bsc o unsucc ho due return

Bsc i unsucc ho due conn

HO failure

Rf channel release


Meas report

Meas result

HO command

HO command

Channel activation



HO access

Establish indication

Ua

HO failureHO failure

Rr

Sabm

New channel release






4015

4012



Figure 27. Unsuccessful external TCH to TCH handover due to MS returning tothe old channel, source BSC.

BTS: MSC: MS: BSC:

Msc o unsucc ho due return



HO command


HO required

Meas report

Meas result

HO failure

HO command

HO command

HO failure HO failure

Ua




MS returns to old channel

4006

4009

4005



Figure 28. Unsuccessful external TCH to TCH handover due to MS returning tothe old channel, target BSC.

BSC:

Msc i end of ho



MS: MSC:BTS:

HO request

Channel activation


HO request ack

Clear command

Rf channel release


Clear complete



4080

4092

4046

HO failure received from BSS1

New channel release



Figure 29. Unsuccessful internal intra-cell TCH to TCH handover due to callclearing during handover.

Signalling can also be partly missing, depending on when the call is cleared.

BTS: MSC: MS: BSC:

Int cell call cleared during ho 4039




Channel activation




Ua

Disconnect

Release complete

Rf channel release


Disconnect

Release complete

ReleaseRelease

Clear command

Channel release

Deactive SACCHDisc

UaRelease indication

Rf channel release


Target channel release

Source channel release

Call cleared during handover by MS








Figure 30. Unsuccessful internal inter-cell TCH to TCH handover due to callclearing during handover.

Counter 4042 is updated in the source cell. Counter 4081 is updated in the targetcell. Signalling can also be partly missing, depending on when the call is cleared.


Bsc i end of ho

Bsc o call cleared during ho

Release complete

Rf channel release




Channel activation



HO access


DisconnectDisconnectRelease

Sabm

ReleaseRelease complete

Clear command

Clear complete

Channel releaseDeactive SACCH

DiscUa

Release indication







Call cleared during HO by MS

4081

4042

Source channel release

Target channel release



Figure 31. Unsuccessful external TCH to TCH handover due to call clearingduring handover, source BSC.

Signalling can also be partly missing, depending on when the call is cleared.

BTS: MSC: MS: BSC:

Msc o call clear during ho



HO command

Rf channel release


HO required

Meas report

Meas result

Clear complete


Clear command

Disconnect Disconnect

ReleaseRelease

Release completeRelease complete

Channel release

Deactive SACCHDisc

UaRelease indication

4041

4009

4005

Call cleared during HO by MS






Figure 32. Unsuccessful internal intra-cell TCH to TCH handover because noradio resources are available due to switch_crc_pool.

BTS: MSC: MS: BSC:

Int unsucc a int circ type 4098


Meas report

Meas result





Unsuccesful reservation with cause switch_crc_pool




Figure 33. Unsuccessful internal inter-cell TCH to TCH handover because noradio resources are available due to switch_crc_pool.

Counter 4071 is updated in the source cell. Counter 4063 is updated in the targetcell. Counters 4063 and 4071 are updated only if the target cell is non-optimum.


Bsc i unsucc a int circ type

Bsc o unsucc a int circ type

Bsc o nonopt at

Bsc i nonopt at

Meas report

Meas result




Unsuccessful reservation with cause switch_crc_pool


4097

4096

4071

4063



Figure 34. Unsuccessful external TCH to TCH handover because no radioresources are available due to switch_crc_pool, target BSC.

BSC:

Msc i unsucc due a if crc



MS: MSC:BTS:

HO request

HO failure





4101

4092

4046



Figure 35. Successful handover type reselection from an internal intra-cell TCHto TCH handover to an external handover due to switching the circuitpool.

BTS: MSC: MS: BSC:



Msc o succ ho


Msc o gen ho required msg

Ho att due switch circ pool

Msc o tch tch at

Msc o att switch circ pool

Int unsucc a int circ type

Meas report

Meas result



Rf channel release


HO required

HO command


Clear command

Clear complete

4095

4049

4004

4009

4005

Old channel release


External HO begins

HO command from target BSC to the source BSC

4099

4052

4094

4098


HO type reselection due switching circuit pool from intra to external HO






Figure 36. Successful handover type reselection from an internal inter-cell TCHto TCH handover to an external handover due to switching the circuitpool.


BTS: MSC: MS: BSC:

Bsc o unsucc a int circ type



Msc o succ ho



ho att due switch circ pool

Msc o tch tch at

Msc o att switch circ pool

Bsc i unsucc a int circ type


Rf channel release


HO required

HO command


Clear command

Clear complete

HO measurement, HO decision --> inter-cell HO attempt, old channel

New channel reservation and activation in new BTS

HO type reselection due switching circuit pool from inter to external HO



4096

4099

4052

4094

4097


External HO begins

HO command from target BSC to the source BSC

4095

4049

4004

4009

4005

Old channel release



Figure 37. Unsuccessful external TCH to TCH handover because the MSCrejects the handover due to various causes, source BSC.

BTS: MSC: MS: BSC:

Msc o unsucc due a if crcMsc o fail lackMsc o adj cell id errMsc o end of hoMsc o ho not allowed


HO reject

HO required

Meas report

Meas result



Channel reservation and activation in new (target) BSC

MSC rejects handover with different causes

Call continuous on old channel

4102 or4055 or4100 or4007 or4037

4005



Figure 38. Unsuccessful external TCH to TCH handover due to GSM timer T8expiry, source BSC.

Counter 4107 is also updated if the MSC sends a CLEAR_COMMAND messagewith a cause other than call control or handover successful.

BTS: MSC: MS: BSC:

Msc o call drop dur ho

Timer T8 Expires

Start timer T8

Msc o end of ho



HO command

Rf channel release


HO required

Meas report

Meas result

Clear complete

HO command

HO command

Clear command

Clear request




4009

4005

Timer T8 expires on source BSC while waiting for Clear command

4107

4007



Figure 39. Unsuccessful external TCH to TCH handover due to adjacent cellerror, source BSC.

The MSC sends a HO_REJECT message with cause invalid_cell or the sourceside BSC notices that the target side identification information is invalid in theHO_COMMAND message.

BTS: MSC: MS: BSC:

Msc o adj cell id err


HO reject

HO required

Meas report

Meas result

HO failure



Channel reservation and activation in new (target) BSC, HO reject from MSC

Target cell information (BCCH frequency or / and BSIC) differs from that in source

BSC radio network configuration database, Alarm 2725 is set


4100

4005



Figure 40. Unsuccessful internal intra-cell TCH to TCH handover, caused by aninternal timer expiry in the BSC or a CONNECTION_FAILURE,ERROR_INDICATION, or ERROR_REPORT message coming tothe target channel.

The MS returns to the old channel.

BTS: MSC: MS: BSC:

Int cell unsucc ho due return 4022

Error report

Meas report

Meas result



Channel activation


Assignment command

Assignment command

Connection failure

Error indication

Assignment failure

Rf channel release


Assignment failure










Figure 41. Unsuccessful internal inter-cell TCH to TCH handover due to a radiolink failure during handover.

A RELEASE_INDICATION, CONNECTION_FAILURE orERROR_INDICATION message comes to the source channel. The signalling canbe partly missing depending on where the failure takes place. Counter 4017 isupdated in the source cell. Counter 4081 is updated in the target cell.


Bsc i end of ho

Bsc o end of ho due bss

Rf channel release

Rf channel release


Meas report

Meas result

Release indication

Connection failure

Channel activation


Error indication


4081

4017





New TCH channel release in the new BTS




Figure 42. Unsuccessful internal inter-cell TCH to TCH handover caused byinternal timer expiry or a failure in the connection of a bi-directionalspeech path.

Counters 4017 and 4084 are updated in the source cell. Counters 4013 and 4083are updated in the target cell.


Failure

Bsc i drop calls

Bsc i unsucc ho due bss probl

Bsc o drop calls

Bsc o end of ho due bss




Channel activation



HO access



Sabm

Rf channel release


Clear request

Clear command

Channel releaseDeactive SACCH

Disc

Release indicationUa

Clear complete

Target channel release in new BTS


4083

4013

4084

4017

Connection of bidirection speech path fails or internal timer expires








Figure 43. Unsuccessful external TCH to TCH handover due to a radio linkfailure during handover, source BSC.

A CONNECTION_FAILURE, ERROR_INDICATION or ERROR_REPORTmessage comes to the source channel, or an internal timer expires.

BTS: MSC: MS: BSC:

Msc o end of ho due bss

Connection failure

Rf channel release


HO required

Meas report

Meas result

HO failure

Error indication

Error report

4008


Failures on source






Figure 44. Unsuccessful external TCH to TCH handover due to a radio linkfailure during handover, target BSC.

A CONNECTION_FAILURE, ERROR_INDICATION or ERROR_REPORTmessage comes to the target channel, or an internal timer expires. Signalling canbe partly missing depending on where the failure takes place.

BSC:

Msc i unsucc ho due conn



MS: MSC:BTS:

HO request

Channel activation


HO request ack

HO access

HO detection HO detection

Physical info


Ua

Error indication

Error report

Connection failure

HO failure

Rf channel release


4002

4092

4046






Figure 45. Unsuccessful external TCH or TCH handover, source BSC.

The GSM timer T7 expires in the source BSC.

BTS: MSC: MS: BSC:

Msc o fail lack

Timer T7 expires

Start timer T7


HO required

Meas report

Meas result


4055

4005

Timer T7 expires on source BSC






Figure 46. Unsuccessful external TCH to TCH handover, target BSC.

The handover fails because the MSC sends a CLEAR_COMMAND messagewith a cause other than call control or radio interface failure revision to oldchannel. Counter 4108 is also updated if the GSM timer T9113 expires.

BSC:

Msc i call poss drop dur ho

Msc i end of ho



MS: MSC:BTS:

HO request

Channel activation


HO request ack

Clear command

Rf channel release


Clear complete

New channel release

HO failure received from BSS1



4108

4080

4092

4046



Figure 47. Successful internal intra-cell TCH TCH HSCSD handover from twoto one channel.

BTS: MSC: MS: BSC:



Channel activation

Assignment command

Assignment command


Ua

Rr HO performed

Rf channel release





Rf channel release


Normal intra-cell HO counters are updated, see figure 1

Old channels are released




Only one suitable channel free

Normal intra-cell HO cause counter is updated, see figure 1


Two channel allocated for HSCSD call on source

Intra succ dec for HSCSD 4127

Intra succ for HSCSD 4125

Cell TCH TCH 4073

Intra att for HSCSD 4124


Int cell success ho 4018



Figure 48. Successful internal intra-cell TCH TCH HSCSD handover from oneto three channels.

BTS: MSC: MS: BSC:



Channel activation



Ua

Rr HO performed

Rf channel release





Channel activation

Channel activation



One channel allocated for HSCSD call on source


Normal intra-cell HO cause counter is updated, see figure 1





Normal intra-cell HO counters are updated, see figure 1

Old channels are released

Intra att for HSCSD 4124

Intra succ inc for HSCSD 4126

Cell TCH TCH 4073

Int cell success ho 4018


Intra succ inc for HSCSD 4126



Figure 49. Successful internal inter-cell TCH TCH HSCSD handover from threeto one channel.


HO performed

Rf channel release





HO access



Rr

Sabm


Rf channel releaseRf channel release


Three channel allocated for HSCSD call on source


Normal inter-cell HO cause counter is updated, see figure 2


Only two suitable channel free

Channel activation


Channel activationChannel activation ack




Bsc i succ dec for HSCSD 4123

Bsc i succ for HSCSD 4121

Bsc o succ for HSCSD 4119

Bsc i TCH TCH 4056

Bsc i nonopt 4062

Bsc i success ho 4010

Bsc o TCH TCH 4064

Bsc o nonopt 4070

Bsc o success ho 4014

Bsc i nonopt att 4063

Bsc o nonopt att 4071

Bsc o att for HSCSD 4118

Bsc i att for HSCSD 4120

Bsc o TCH TCH att 4067

Bsc i TCH TCH att 4059



Figure 50. Successful internal inter-cell TCH TCH HSCSD handover from twoto three channels.


HO performed

Rf channel release



Channel activation



HO access



Sabm


Channel activation

Channel activation



Rf channel release





Normal inter-cell HO cause counter is updated, see figure 2

Two channel allocated for HSCSD call on source



Bsc i succ inc for HSCSD 4122

Bsc i succ for HSCSD 4121

Bsc o succ for HSCSD 4119

Bsc i TCH TCH 4056

Bsc o TCH TCH 4064

Bsc i nonopt 4062

Bsc i success ho 4010

Bsc o nonopt 4070

Bsc o success ho 4014

Bsc i nonopt att 4063

Bsc o nonopt att 4071

Bsc o att for HSCSD 4118

Bsc i att for HSCSD 4120

Bsc o TCH TCH att 4067

Bsc i TCH TCH att 4059



Figure 51. Successful external TCH TCH HSCSD handover from two to twochannels, source BSC.

BTS: MSC: MS: BSC:

HO command

Rf channel release


HO required


Clear complete


Clear command

Rf channel release



Normal external HO cause counter is updated, see figure 3


Old channels are released in the old BSC

Msc o succ TCH TCH ho 4049

Msc o success ho 4004

Msc o gen ho com msg 4009

Msc o gen ho req msg 4005

Msc o TCH TCH att 4052

Msc o succ for HSCSD 4113

Msc o att for HSCSD 4112



Figure 52. Successful external TCH TCH HSCSD handover from four to onechannel, target BSC.

Counter 4117 is updated only if the target BSC has received information on theamount of channels allocated in the source BSC.

BSC: MS: MSC:BTS:

HO request

Channel activation


HO request ack

HO access HO detection HO detection

Physical info


Ua

HO complete

Rr

HO complete

HO completed


Channel reservations and activations in the new BTS

HO measurem. and external HO decision done in source BSC, MSC sends HO request

Four channel allocated for HSCSD on source BSC


Msc i succ dec for HSCSD 4117

Msc i succ for HSCSD 4115

Msc i succ TCH TCH ho 4043

Msc i TCH TCH ho att 4046

Msc i success ho 4000

Msc i att for HSCSD 4114



Figure 53. Successful external TCH TCH HSCSD handover from one to twochannels, target BSC.

Counter 4116 is updated only if the target BSC has received information on theamount of channels allocated in the source BSC.

BSC: MS: MSC:BTS:

HO request

Channel activation


HO request ack

HO access HO detection HO detection

Physical info


Ua

HO complete

Rr

HO complete

HO completed

Channel activation




HO measurem. and external HO decision done in source BSC, MSC sends HO request

One channel allocated for HSCSD on source BSC

Channel reservations and activations in the new BTS

Msc i succ TCH TCH ho 4043

Msc i succ for HSCSD 4115

Msc i succ inc for HSCSD 4116

Msc i TCH TCH ho att 4046

Msc i success ho 4000

Msc i att for HSCSD 4114



Figure 54. Internal intra-cell direct access from regular DCCH to a super-reuseTRX.

The optional feature BSS7057 Direct Access to Super-reuse TRX in IUO must beactivated.

BSC:

Int cell success hot

Cell sdcch tch att

Cell sdcch tch

Ho due direct access att

MS: MSC:BTS:

Assignment request



Channel activation




Ua

Rr

Assignment complete

Rf channel release


Assignment complete Assignment complete

Alert Alert


Connect Connect

Basic call signalling

4077

4128


TCH reservation and activation

Signalling on SDCCH

Signalling on FACCH - TCH

4018

4074

SDCCH release

Connection

Conversation phase



Figure 55. Internal inter-cell direct access from parent DCCH to the child orparent TRX.

The optional feature BSS7057 Direct Access to Super-reuse TRX in IUO must beactivated. Counters 4128, 4068, 4014 and 4065 are updated in the source cell.Counters 4060, 4010 and 4057 are updated in the target cell.

BSC:

Bsc o sdcch tch

Bsc i sdcch tch

Bsc i success ho

Bsc i sdcch tch at

Bsc o sdcch tch at

Bsc o success ho

Ho due direct access att

MS: MSC:BTS:

Assignment request

HO access


Channel activation


HO detection


Ua


Rf channel release



Alert Alert


Connect Connect

Physical info

Basic call signalling

4060

4068

4128


Signalling on SDCCH on old BTS


4065

4057

4010

4014

SDCCH release

Connection

Conversation phase



Figure 56. Internal inter-cell direct access from the TCH on a child TRX to theTCH on a parent TRX.

Optional feature BSS7057 Direct Access to Super-reuse TRX in IUO must beactivated. Counters 4031, 4067, 4014 and 4064 are updated in the source cell.Counters 4059, 4010 and 4056 are updated in the target cell.

BSC:

Cause umbrella ho

Bsc o tch tch

Bsc i tch tch

Bsc i success ho

Bsc i tch tch at

Bsc o tch tch at

Bsc o success ho

MS: MSC:BTS:

Meas report

HO access


Channel activation


HO detection


Ua

Rr HO performed

Rf channel release



Physical info

Meas result


4031

4064

4056

4010

4059

4067

4014







Figure 57. Handover attempt due to a BSC controlled TRHO.

Channel activation


Rf resource indication

HO signalling continues

HO measurements

BSC: MS: MSC:BTS:

Cause HO started by traffic reason 4035



Figure 58. Handover attempt due to DADL/B.

Related topics



Channel activation


Assignment request



BSC: MS: MSC:BTS:

HO attempt due to dadl/b 4129

Signalling

Signalling continues


4 handover

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tch handover

sdcch handover

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