rf baseline parameter

8/2/2019 Rf Baseline Parameter

1/77

RF Baseline Parameter

ISSUE 1.0


2/77


3/77

Network Identity Parameter

Cell Global Identity(CGI)

Base Station Identity

Code (BSIC)


4/77


CGI CGI=MCC+MNC+LAC+CI Once MS receives SYS INFO, it decodes the CGI

information, and decides whether it can stay in the

cell according to the MCC and MNC indicated by

CGI. At the same time, it judges whether the currentlocation area is changed, so as to decide whether to

execute location update. During the location update

process, MS will report the new LAI to the network,

so that the network can know the LA in which MS is

currently located.


5/77


CGIMCC MNC LAC CIFull Name Mobile Country

Code

Mobile Network

Code

Location Area

Code

Cell Identity

Type Dec Dec Hex Hex

Rage 000~999 00~99 0001~FFFE 0000~FFFF

LACLAC adopts hexadecimal coding. The available range

is from 0001H to FFFEH. The code 0000H and FFFFH

cannot be used (please refer to specification GSM0303, 0408,

and 1111).

One location area can contain one or more cells. The same

LAC can exist in different BSC, but can not exist in different

MSC.


6/77

Case Study: Incorrect CGI causes MS

unable to register on the network.

Case description

The subscriber complained that MS could not register to the

network, or it was difficult to register to the network between BTS A

and B, or no network mark was displayed on the MS, but MS

indicated that the signal was very good. Some subscribers also

complained that MS could make MTC could not make MOC. Cause analysis

CGI of the cell was modified. So the network register flow was not

normal. Although the signal was very good, MS could not get

registered in the network.

Recommendation and summary

CGI is a very important parameter and should be configured

correctly, thus to ensured that the CGI data in BSC and MSC are

the same.


7/77


BSICNCC BCC

Full Name Network Color

Code

Base Station

Color Code

Contain 3 bits 3 bits

Range 0~7 0~7

BSIC is transmitted on Synchronous Channel (SCH)

NCC is used to identify different Base Station from different GSM

PLMN

NCC Permitted should work with NCC

BSIC=NCC+BCC


8/77

Cell C: BCCH 97

Case Study BSIC

Base Station Identity CodeBSIC

Cell B: BCCH 97

Cell A

BSIC: 12

BSIC: 12

BSIC: 13

NeighborCell List

Serving

Cell

Neighbor Cell

Cell A Cell B

Cell A .


9/77

1 Network Identity Para.

2 Paging Para.

3 Cell Selection and Cell Reselection Para.

4 Assignment Para.

5 Handover Para.

6 Radio Link Control Para.

7 BA1,BA2 Table

8 Dual-band Network Para.

9 Network Function Para.

10 Interference Measurement Para.


10/77

Paging Parameter MSC can resend Paging Command 4 times in A Interface. The resending time

intervals are 3, 3, 2, 2 seconds. 2 seconds after the last Paging Command is sent,

totally 12 seconds after first Paging Command is sent, if MSC does not receive

Paging Response, and then MSC report Voice Announcement that subscriber is out

of coverage.

BSC only transmits the Paging Command.

Whether BTS resends Paging Command, it depends on corresponding BTS version.

(Refer to the Version Description documents)

MSC BSC BTS MS

PagingPaging CMD

PCH: Paging REQ


11/77

Paging Parameter

T3212

ATT CCCH Conf.

BS_AG_BLKS_RES

BS_PA_MFRMS Paging Times


12/77

T3212

Value range: 0~255

Unit: 6 minutes

Content: It is the Periodic Location UpdateTimer. It defines the interval of periodic

location update.

Recommendation: 20~30 (urban), 10~20(suburban), 8~10(mountain area)


13/77

ATT

Value range: Yes, No

ContentIt is used to inform MS whether IMSI attach-

detach is allowed in this cell. If it is set to Yes, the

network will not process the connection to the calledmobile subscriber when MS is power-off. Thus network

processing time and radio resources are saved.

Otherwise the network will process the connection even

though the MS has been powered off.

RecommendationYes


14/77

CCCH Conf

Value range: 1 Non-Compounding CCCH, 1

Compounding CCCH, 2 Non-Compounding CCCHs, 3

Non-compounding CCCHs, 4 Non-compounding

CCCHs.

Content: It is Common Control Channel Configuration.

CCCH configuration determines the capacity of PCH,

AGCH and RACH. This parameter can be automatically

configured by the BSC Data Auto Configuration System

according to the TRX channel configuration.

Recommendation: When there is one TRX in the cell,

one combined CCCH is recommended (in a system with

few paging messages in location area). For others, it is

configured according to the number of TRX in the cell.


15/77

BS_AG_BLKS_RES

Value range: 0~2 (1 combined CCCH),

0~7 (others)

Unit: Block Content: It is also called Access Granted

Blocks Reserved. It is the number of

CCCH channel message blocks that are

reserved in one multi-frame for access

granted channels (AGCH).

Recommendation: 2 (non-combined

CCCH)


16/77

BS_PA_MFRAMES

Value range: 29

Unit: Multi-frame period (51 frames)

Content: It is Paging Channel Multi-frames.It defines the number of multi-frames used

as a cycle of paging sub-channels.

Recommendation: 2


17/77

Paging Times

Value range: The BTS24, BTS3Xr, BTS3001C,

BTS3002C, and dual-transceiver BTSs support

paging re-sending. Paging times: 18

Unit: None Default Value: 4

Content: The BTS2X supports the re-sending

mechanism. Both the BTS3X series and the dual-

transceiver BTSs support paging re-sending. BTS3Xand double-transceiver BTSs will support paging

resending function.


18/77

Case Study: Wrong T3212

setting cause MTC failure

Even if T3212 setting is less than the system (MSC)

query time, the system will still sometimes voice The

subscriber you dialed is powered off.

A B

T3212=4 T3212=8

LAC

Ping-pong Reselect


19/77

Case description

A local GSM network has more than 6000

subscribers. There are four BTSs. The network has

been working properly. But from sometime on, some

MS often lost connection with network suddenly.

The complaint from subscribers in urban area

increased.

Handling procedure

Modify T3212 to 10, i.e. 60 minutes. Modify thecorresponding time of MSC to 180 minutes. Two

days observation shows no subscriber complaint

and the problem is solved.

Case Study: Too small T3212

causes MS lose connection with

network.


20/77


2 Paging Para.


4 Assignment Para.

5 Handover Para.


7 BA1,BA2 Table





21/77

Cell Reselection regulation:

C1


22/77

Cell Selection and Cell

Reselection Parameter

MS_TXPWR_MAX_CCH

RXLEV_ACCESS_MIN

PI

CRO

TO

PT

Cell Bar AccessCBA

Cell Bar QualifyCBQ

Cell Selection Hysteresis

CRH


23/77

C1 = RLA_C - RXLEV_ACCESS_MIN -

MAX((MS_TXPWR_MAX_CCH- P), 0)

RLA_C: MS average receiving level

RXLEV_ACCESS_MINminimum level of

received signals required for the MS to

access the system MS_TXPWR_MAX_CCH: maximum

transmit power level of MS

P: MS maximum transmit power

C1 Formula

Cell Selection Parameter


24/77

MS TXPWR_MAX_CCH

Value range: 0~31

Unit: level

Content: This parameterdetermines the maximum allowed

output power of the MS when it

begins to access a cell and has not

yet received power control

command.

Recommendation: 5(900MHz),

0(1800MHz)


25/77

RXLEV_ACCESS_MIN

Value range: 063 (110 dBm to 47 dBm)

Unit: Level

Default Value: 8

Content: This parameter indicates theminimum level of received signals required for

the MS to access the system. If the parameter

value is small, the required level of received

signals is low. If the parameter value is great,

the required level of received signals is high.


26/77

C2 = C1+ CRO- TO*H(PT-T), ifPT31;

C2 = C1- CRO, ifPT = 31

CRO: CELL_RESELECT_OFFSET

TO: TEMPORARY_OFFSET

PT: PENALTY_TIME , to determine the effect duration of TO

T: a Timer, initial value is 0. When one cell appears in six

maximal the neighbor cell list, the Timer to that cell starts.

When one cell is deleted from the neighbor cell list, the Timer

is restored.

H(x): Neighbor Cell: H(x) = 0, when x < 0; H(x) = 1, when x >=

0.

Serving Cell: H(x) = 0

C2 Formula

Cell Reselection Parameter


27/77

PI

Value range: Yes (1), No (0).

Unit: None

Content: Cell Reselect Parameters Indication,

sent on the broadcast channel of the cell. It isan indication to the existence of Cell Reselect

Offset(CRO), Temporary Offset(TO) and

Penalty Time(PT).

Recommendation: Yes.


28/77

CRO

Value range: 0~63, the

corresponding level value:

0~126dB, stepped every 2dB.

Unit: None

Default Value: 0

Content: Cell Reselect Offset. It isa parameter in C2 calculation to

give an intentional modification in

MS cell reselection.


29/77

TO

Value range: 0~7 , the

corresponding value is 0~60dB, 7

corresponds to Infinite.

Unit: None

Default Value: 0

Content: Cell Reselect TemporaryOffset. It is a parameter in C2

criterion to give a temporary

modification within PT time.


30/77

PT

Value range: 0~31, the

corresponding time is 20~620s. 31

is to change the formula of C2.

Unit: None

Content: Cell Reselect Penalty

Time.

Recommendation: 0


31/77

CBQ

Value range: Yes , No

Unit: None

Content: Cell Bar Qualify. CBQ only affects

the selection of cells but is not related to

cell reselection. It works with CBA to define

the access priorities of cells.

Recommendation: No.


32/77


33/77

Application of CBQ

The traffic of cell A and B is heavy. Set these two cells with

CBA=No, CBQ=No.

A B


34/77

Application of CBA

B is a micro cell. Set B to Normal and A to Low.

B

A


35/77

Application of CBA

CBQ(A) = NO

CBA(A) = NO

A

C

B

D


36/77

CRH

Value range: 0~14 , the step size

is 2

Unit: dB Content: Cell Reselection

Hysteresis. It is the parameter

used when cell reselection

happens between two location

areas.

Recommendation: 4


37/77

Case Study: RXLEV_ACCESS_MIN causes

signal fluctuation Case description

Subscribers complain that the signal fluctuates in a certain

area. On-site test shows that this phenomenon does exist.

From the testing mobile, we can see that there are a lot of

cells signals in this area. Some frequencies are the suburbBTS signals far away from this area. The cell reselection of

MS is rather frequent.

Handling procedure

Modify parameter RXLEV_ACCESS_MIN of all cells in urban

area and make them consistent with each other. The problemof signal fluctuation is solved.

Recommendation and summary

In area with complicated coverage, the

RXLEV_ACCESS_MIN of each cell should be kept same.


38/77


2 Paging Para.


4 Assignment Para.

5 Handover Para.


7 BA1,BA2 Table





39/77


40/77

MS MAX Retrans

Value range: 1, 2, 4, 7

Unit: Time

Content: It is one of the random access control

parameters. MS MAX Retrans is the upper limit of times

that MS is allowed to send Channel Request in one

immediate assignment procedure.

Recommendation:

Set to 7 for areas with low traffic (suburban or rural

area) and the cell radius more than 3 km.

Set to 4 for areas with ordinary traffic (non-busyarea in the city) and the cell radius is less than 3km.

Set to 2 for micro-cell

Set to 1 for micro-cell with heavy traffic or with

obvious congestion.

Set to 4 or 7 for satellite transmission BTS.


41/77

TX-Integer

Value range: 3~12, 14, 16, 20, 25, 32, 50

Unit: RACH timeslot (equals to a TDMA frame, 4.615ms)

Content: Used to calculate the number of timeslots in the

interval between multiple channel requests sent by MS. Recommendation: 20 (If the cell immediate assignment

success rate is low, set the S with a larger value. Select

32 for satellite transmission, so as to reduce satellite

transmission delay).


42/77


43/77

TCH Immediate Assignment


Unit: None

Default Value: No Content: Yes: It indicates that the

TCH is immediately assigned when

the SDCCH has no availableresource during the processing of

access request. No: It indicates that

only the SDCCH can be assigned.


44/77

RACH Min Access Level

Value range: 0-63 (-110 dBm to -47

dBm)

Unit:N

one Default Value: 5

Content: This parameter must be

set according to the actualsensitivity of the BTS and the

minimum access level of the MS so

that calls can be made when there

is signal.


45/77


2 Paging Para.


4 Assignment Para.

5 Handover Para.


7 BA1,BA2 Table





46/77

Handover Parameter

NCC Permitted

Max Resend Times of Phy. Info

T3105

MSOldBTS BSC

Measure Report

NewBTS MS

Measure Report CHANACTIV

CHANACTIV ACKHO CMDHO CMD

HO ACCESSPHYSICAL INFHO DETECTION

SABM

UAEST IND

HO COMPLETE


47/77

NCC Allowed

Value range: Check box, including options

0~7.

Content:N

etwork Color Code, sent insystem information 2 and 6. It lists NCC

that need be measured by MS. If a

neighbor cells NCC is permitted, MS will

report MRs of it to the network.

Recommendation: Subject to the concrete

conditions.


48/77

Max Resend Times of Phy. Info

Value range: 1255

Unit: None

Default Value: 30 Content: This parameter indicates

the maximum times of resending

physical information. Recommendation: Subject to the

concrete conditions.


49/77

T3105

Value range: 0255

Unit: 10ms

Default Value: 7 Content: When BTS sends physical

information to the MS, the BTS

starts the timer T3105.If the timerT3105 times out before receive the

SAMB frame from MS, BTS re-

sends physical information to MS

and restarts the timer T3105.


50/77

Direct Retry


Unit: None

Content: This parameter indicates the whether

the directed retry on the TCH is allowed. If this

parameter is set to Yes, the handover procedureis used and the MS is handed over to the

neighboring cell. Direct retry is an emergency

measure for abnormal peak traffic in the local

wireless network. It is not a primary method ofclearing traffic congestion. If direct retry is

preformed frequently in a local network, you

must adjust the sector carrier configuration of

the BTS and the network layout.

Recommendation: Yes


51/77


2 Paging Para.


4 Assignment Para.

5 Handover Para.


7 BA1,BA2 Table





52/77

Radio Link Control Parameter

BS-PA-MFRMS (Idle Mode)

Radio Link TimeoutRLINKT

(Active Mode, DL)

SACCH Multi-frames (Active

Mode, UL)


53/77

BS_PA_MFRAMES

Value range: 29

Unit: Multi-frame period (51 frames)

Content: It is Paging Channel Multi-frames. It defines the number of

multi-frames used as a cycle of paging sub-channels.

Recommendation: 2 Note: In idle mode MS camps in a cell. The DSC is initialized to the

integer part of 90/N (N is BS_PA_MFARMES, with the value range:

2~9). when MS can successfully decode the message on paging

sub-channel, DSC will increase by 1, but it will not exceed initially

value. If decoding fails, DSC will decrease by 4. If DSC


54/77

Radio Link Timeout

Value range: 4~64, the step size is 4

Unit: SACCH period (480ms)

Content: This parameter is used for MS todecide down-link disconnection in case of

SACCH decoding failures.

Recommendation: 20~56


55/77

Application of Radio Link

Timeout

Impact of radio link timeout

A B

P Q

Poor coverage


56/77


57/77


2 Paging Para.


4 Assignment Para.

5 Handover Para.


7 BA1,BA2 Table





58/77

Neighbor Cell Description

There are table BA1 and table BA2.

Table BA1 describes BCCH frequencies of

the adjacent cells to be measured when

the MS is in idle mode.

Table BA2 describes BCCH frequencies of

the adjacent cells to be measured when

the MS is in dedicated mode.


59/77

Theoretical Neighbor Cells Actual Neighbor Cells

B

CA

D

B

CA

D

Application ofNeighbor Cell

Description


60/77

B

C

A

A

Application ofNeighbor Cell

Description


61/77

Case Study: Island effect

Case Description During the process of optimization in a certain area, it is

found out that the signal is poor in a certain section of

suburban highway. The signal strength measured is less

than -95dBm.

Handling Procedure Modify the data in BSC. Add neighbor relationship to Cell A

and B for each other. The coverage problem is thus solved.

C

B

A-92

-80

-95


62/77


2 Paging Para.


4 Assignment Para.

5 Handover Para.


7 BA1,BA2 Table





63/77

Dual-band Network Parameter

ECSC MBR


64/77

ECSC


Content: Early Classmark Sending Control. It

indicates if an MS in the cell is allowed to use

early Classmark sending. See Protocol 0408. Recommendation: No.


65/77

MBR

Value range: 0~3

Content: Multi-band Reporting. It is used

to inform MS to report the adjacent cells in

a controllable way. It is sent in the System

Information 2ter and 5ter.


66/77

Application of MBR

-92dBm-82dBm

AB

C -68dBm

D -90dBm

E -78dBm

F -88dBm

G -96dBm

H -84dBm

GSM1800

GSM900S


67/77


2 Paging Para.


4 Assignment Para.

5 Handover Para.


7 BA1,BA2 Table





68/77

Network Function

Parameter UL DTX (Uplink Discontinuous

Transmission)

DL DTX (Downlink

Discontinuous Transmission)

Support Half Rate

Call Re-establishment Forbidden

Emergent Call Disable


69/77

UL DTX

Value range: May use, Shall use, Shall not use.

Unit: None

Default Value: Shall use

Content: It is used to indicate whether MSuses DTX function. In System Information 3, it

is 2-bit coding. In System Information 6, it is 3-

bit coding. It shows the DTX state of the MS in

the previous measurement period.

Recommendation: Shall use.


70/77


71/77

Support Half Rate

Value range: Yes, No.

Unit: None

Default Value:N

o Content: This parameter indicates whether

the half-rate function is supported in this

cell. It is one of the cell reselection

parameters in the system message 3.

Refer to GSM Rec. 04.08.


72/77

Call Re-establishment Allowed


Unit: None

Default Value: Yes Content: This parameter indicates

whether the network allows call re-

establishment. Yes means do not

allow to use call re-establishment.


73/77

Emergent Call Disable


Unit: None

Default Value: No Content: Emergence Call Disable.

When EC Disable is set to No, it

means emergency call is permitted.

Otherwise it is prohibited.


74/77


75/77

I t f B d Th h ld


76/77

Interference Band Threshold

0~5 Value range: 110~85

Unit: -dBm

Content: It decides the corresponding value for each interference

band (from band 0 to band 5) and used to measure the uplink

interference during the TCH timeslot is in idle mode. Recommended values:

110 ( Interference band threshold 0)


98 ( Interference band threshold 2 )





77/77

Interf Calculation Period

Value range: 1-31

Unit: SACCH period (480 ms)

Default Value: 20 Content: Before the BTS transmits

the radio resource indication

message to the BSC, the

interference levels measured on

idle channels in the period defined

by this parameter are averaged.

rf baseline parameter

Documents