bsspar-idle mode operation

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BSSPAR

Idle Mode Operation

Training Document

BSSPAR CTXX 03

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The information in this document is subject to change without notice and describes only theproduct defined in the introduction of this documentation. This document is intended for theuse of Nokia Networks' customers only for the purposes of the agreement under which thedocument is submitted, and no part of it may be reproduced or transmitted in any form ormeans without the prior written permission of Nokia Networks. The document has been

prepared to be used by professional and properly trained personnel, and the customerassumes full responsibility when using it. Nokia Networks welcomes customer comments aspart of the process of continuous development and improvement of the documentation.

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Nokia Networks' liability for any errors in the document is limited to the documentarycorrection of errors. Nokia Networks WILL NOT BE RESPONSIBLE IN ANY EVENT FORERRORS IN THIS DOCUMENT OR FOR ANY DAMAGES, INCIDENTAL ORCONSEQUENTIAL (INCLUDING MONETARY LOSSES), that might arise from the use of thisdocument or the information in it.

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Other product names mentioned in this document may be trademarks of their respectivecompanies, and they are mentioned for identification purposes only.

Copyright Nokia Oyj 2003. All rights reserved.

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Contents

1 Module Objectives................................................................................4

2 Idle Mode Control.................................................................................5

3 PLMN Selection....................................................................................83.1 PLMN Access Parameters...................................................................93.2 Cell and Location Area Parameters...................................................103.3 Measurement Reporting ...................................................................12

4 Cell Selection & Reselection.............................................................14

4.1 C1 Criterion 154.2 C2 Criterion 164.3 C31 & C32 Criteria............................................................................19

5 Location Updates...............................................................................205.1 IMSI Attach & Detach........................................................................22

6 Key Learning Points...........................................................................24

7 Review Questions ..............................................................................26

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1 Module Objectives

At the end of the module, the participant will be able to:

List the functions of the MS during the idle mode

Explain the parameters used for PLMN and cell selection

State the purpose of location updates and the associated parameters

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2 Idle Mode Control

Because of the limited radio spectrum that is available, each MS cannot be

allocated a dedicated traffic channel (TCH) at all times. Traffic channels areonly allocated to the user when the need arises. This leads to the distinction

between two states that the mobile can take, namely Idle Mode and Dedicated

Mode.

In the idle mode, an MS does not have a dedicated traffic channel (TCH). It

listens to and transmits on the broadcast channels. All requests for transmission

resources are made while in idle mode. Once the resources are allocated for full

duplex point-to-point communication, the mobile moves from idle mode to

dedicated mode.

When the MS is switched ON When there is no dedicated connection

When?

To camp on the best suitable cell

Why?

For MS to receive system info from the NW on DL For MS to be able to initiate a call whenever needed

For the NW to be able to locate the MS when there is a MT call/S

Why to camp on a specific cell?

PLMN selection Cell selection & re-selectio Location updates

Idle Mode Tasks

Figure 1. Idle mode operation

During the idle mode, the MS has to perform a number of functions:

(a) During Power On it has to check if it can access a PLMN and cell.

(b) It has to stay in contact with the BTS by decoding the BSIC and listening to

System Information messages.

(c) Listening to BTS transmission for paging messages to see if it being called.

(d) Monitor the status of radio links from various BTS and choose the most

appropriate BTS.

(e) Listen for cell broadcast short messages.

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locationAreaId

ncc (Network C olour C ode) 0 7bcc (BTS Colour Code) 0 7

bsIdentityCode

cell-ID 0 65535

Parameter Value

trainingSequenceCode 0 7

mcc (Mobile Country Code) 0 999mnc (Mobile Network Code) 0 99lac (L ocation Area Code) 0 65535

Cell G lobal Identity MCC + MNC + LAC +

Figure 2. IDs and ID codes

When the mobile station is in idle mode, it needs some information about the

GSM network in order to know the right frequencies and find the right cells.

This information pertains to Radio Resource Management and to Mobility

Management and includes:

The access parameters to the PLMN

Location Area Identification (LAI), which is composed of the MobileNetwork Code (MNC), the Mobile Country Code (MCC) and Location

Area Code (LAC). LAI = MCC + MNC + LAC

Cell Identification Code

Base Station Identity Code (BSIC) including Network Colour Code

(NCC) and Base Station Colour Code (BCC).

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BSIC is a combination of NCC and BCC

Reported in Measurement Results to BSC

Can be listed in Hex or Decimal

NCC (0...7) BCC (0...7)

4 2 U 4 2 U

32 16 8 4 2 U Range

0 0 0 x x x 0 - 7

0 0 1 x x x 8 - 15

0 1 0 x x x 16 - 23

0 1 1 x x x 24 - 31

1 0 0 x x x 32 - 39

1 0 1 x x x 40 - 47

1 1 0 x x x 48 - 55

1 1 1 x x x 56 - 63

Figure 3. Base Station Identity Code (BSIC)

Once the base station is identified within the network, the initial frequency must

be set for each TRX.

The basic idea in the GSM system is that the mobile is always within the cell

offering the best coverage and that the system knows where the MS is located.

In idle mode, mobility is ensured by setting the following criteria and timers:

Cell selection criteria based on C1 or C2 comparison

Location Update

IMSI attach/detach

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3 PLMN Selection

When a mobile station is switched on, it tries to locate a GSM network. If the

MS is in the home country, it naturally tries to find the home network. If there iscoverage, the MS camps on the home network. If there is no coverage, the MS

attempts to find other networks of competitive operators and this is called

national roaming. Usually this is not possible because different operators are in

competition with each other. Then the only possibility of finding a network in

the home country is to find the home network.

When the MS is abroad, international roaming is usually possible. The Mobile

can select any operator offering GSM service in the foreign country, with which

the operator of the home network has a roaming agreement. The issue is how

the MS selects the network in a foreign country. There are 3 possibilities:

1. The home operator can make a list of preferred operators in different

countries. This list of preferred networks is not used.

2. The MS just selects the network with the best field strength level found

where the mobile is switched on. The Mobile camps on the network

selected and stays on it as long as service (coverage) is available. Usually,

the selection is made based on the field strength level only.

3. Home operator can give a list of forbidden networks.

The PLMN selection criteria mentioned above are chosen by the operator and

they cannot be affected with the parameters which will be discussed next.

An operator can control PLMN selection in a number of ways:

a) Specify a class of MS that is allowed to access a particular cell.

b) Specify the minimum received level signal strength required by the MS.

c) Bar some cells from user access except for emergency calls.

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plmnpermitted 0 ... 7

Parameter Value

NOTEThis parameter is confusing. Its not used fornetworkselection. Its used AFT ER a network has beenselected so thatmeasurementsfrom only one PLM N are reported

Two M odes

Automatic - utilises a list of P LM Ns in priority order. Highest priori(available and allowable) PLMN is selected

Manual - MS indicates to user which P LM Ns are available Three Types of Lists

P referred

Found

Forbidden

Figure 4. PLMN Selection

3.1 PLMN Access Parameters

A number of parameters are needed to control which MS is allowed to access a

PLMN, BTS or Cell.

The parameter notAllowedAccessClasses (ACC)(BTS)(0..9, 11..15) tells

which mobile user classes can not use a particular cell. This allows the operator

to divide the subscriber database into different Access Control Classes and

hence gives the operator some control over the existing load and access to

priority users in congested cells.

The plmn-permitted (PLMN)(BTS)(0..7) parameter is broadcast on the BCCH

and is used by the mobile to report measurements of that PLMN. This

parameter is used after the network selection has been done. The BSIC (Base

Station Identity Code) is broadcast on the SCH, so when the mobile pre-

synchronises, it knows if the BTS belongs to the right PLMN or not (BSIC is

screened by plmn-permitted (PLMN)(BTS)).The parameterplmn-permitted (PLMN)(BTS)(0..7), doesnt affect the PLMN

selection, it is only used for measurements reporting.

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3.2 Cell and Location Area Parameters

AN MS needs information about cell identities. First, there is identity of the

each cell (cell-ID) and in addition to this cell-ID more IDs, which are used forlocation information.

ParameterlocationAreaId (LAC)(BTS) includes the following:

Mobile Network Code, mnc (0..99),

Mobile Country Code, mcc (0..999) and

Location Area Code, lac (0..65535) which describes each location

area as shown in Figure 5.

Location Area Code

MNC =Operator

MCC =Country e.gFinland

LAC 1 =Helsinki LAC 2

LAC 3 LAC 4BSC

BTSBTS BTS1 2 n

Figure 5. Description of a location area.

There is other information used for Radio Channel Management purposes.

Some information is needed in order to separate co-channels used in different

Base Stations in the vicinity as shown in Figure 6.

ParameterbaseStationIdentityCode (BCC)(BTS) includes

Network Colour Code, ncc (0..7) and

Base Station Colour Code, bcc (0..7)

It is possible to set these parameters into the Background Database, to

minimise downtime.

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BaseStationColour Code

f1

f2

f3

f1

f1

bcc=1

bcc =2

bcc =3

Figure 6. Base Station Colour Code.

Parameter Value

bCC HAllocation-ID 1 ... 255bCCHAllocationList 1 ... 124 in GSM (max. 32freq. for all bands)

idleStateBCCHAllocation 0 (BCCH list is taken from the adjacent cell)1 ... 255 (number of the BC CH list used)

measurementBCCHAllocation ADJ (BCCH frequency list taken from adj. cIDL E (active MS uses same list as MS in IDL

initialFrequency 1..124 & 975..1023, 0; 512..885 GSM900;1800 (FRE

Figure 7. Frequencies

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3.3 Measurement Reporting

After the MS accesses one network, it reports the measurements of the network

to the BTS on which it is camped. However, there are also some other

requirements to access one cell. Having coverage might not be enough to access

some particular cells.

The parameter RxLevAccessMin (RXP)(BTS)(-110..-47 dBm) describes the

minimum value of received field strength required by the MS to get any service

from the network in that cell in idle mode.

However, there are still some cases, even if there is good field strength where,

the operator may want to make some tests to keep a cell out of use. For this kind

of purposes the cell can be changed to barred state by using the parametercellBarred (BAR)(BTS)(Yes/No) parameter.

An example of using cell barring for test measurements is given in Figure 8.

Cell Barred

Existing LayerBarred, No

New Microcell LayerBarred, Yes

Easy to test new Microcells with NMS/X 5.24 with Nokia 2110

GPS-satelite

NMS/X 5.2

Figure 8. Use of Cell Barring for test measurements.

NOTE: All adjacent cells have to be also barred.

A Mobile can not use any cell for call establishment, which is in barred state.

An exception to a barred cell could be implemented using parameter

emergencyCallRestricted (EC)(BTS)(Yes/No). This parameter tells if the

mobile has right to use the network for emergency calls even if it has no right to

use the network for normal calls. Only for MS classes 11 to 15.

The network also broadcasts (on the BCCH) some parameters related partly to

network planning to mobiles. When the mobile is moving in Idle mode it has to

know which is the best cell offering service in each area.

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CellReselectHysteresis (HYS)(BTS)(0..14 dB) is a parameter that the mobile

uses as a margin in the comparison of the field strength levels of the adjacent

cells in different Location Areas in Idle mode. This margin prevents ping-pong

location updates, which will result in a waste of SDCCH capacity.

The other parameter which is actually directly related to frequency planning is

msTxPwrMaxCCH (TXP)(BTS)(13..43 dBm) which tells the mobile the

maximum transmitting power when accessing the system.

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4 Cell Selection & Reselection

One basic idea in the GSM system is that the Mobile Station is always within

the cell offering the best coverage. In Dedicated mode this is handled byhandovers, but in Idle mode the concept of handover does not exist because the

MS does not have a dedicated channel. Mobile has to find the best cell in each

area. There is a process for this purpose called Cell Selection, based on C1 or

C2 comparison.

The idea is that the Mobile compares field strength levels coming from different

BTSs and selects the best BTS. The mobile uses the parameter

CellReselectHysteresis (HYS)(BTS)(0..14 dB) parameter between cells that

belong to different Location Areas in order to avoid the "Ping-Pong"

phenomenon. This means that before the mobile changes to a different cell in

Idle mode, between different location areas, the field strength level of the new

cell has to be at least the value ofCellReselectHysteresis (HYS)(BTS) betterthan the value of the serving cell.

There is no margin between the cells that belong to the same Location Area.

The equation for the cell selection is presented next.

Two methods for selecting a cell:

Normal cell selection(a)- MS has no prior knowledge of which RF chanBCCHStored list cell selection - optional(b)- MS uses list of BCCH carriers used

PLMN

If no suitable cell is found using method(b)then(a)is tried.

What constitutes a 'suitable' cell:

Cell is in the selected PLM NCell is not barredIt is not in a forbidden location area for national roamingC1 >0 (range -99..0..+99)If there is no normal priority cell then low priority cell

Figure 9. Cell Selection in Idle mode

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4.1 C1 Criterion

The C1 criterion has been designed to maximise transmission quality. It takes

into account the following

L = Average Level of the signal received by the mobile station on the

beacon frequency.

p1 = RxLevelAccessMin (RXP)(BTS)(-110 -47 dBm) discussed

earlier.

M = Maximum RF power of the MS based on the MS specifications.

p2= MxTxPwrMaxCCH(TXP)(BTS)(13 43 dBm) discusses earlier

C1 is defined as follows

C1 = (A Max (B, 0))

Where A = L p1

And B= p2 M

When looking for cells (neighbouring or during Power On), only cells of

positive C1 computed from the broadcast parameters p1 and p2 values are taken

into account. The cell with the best C1 is chosen. Thus the C1 criteria is used to

determine the coverage limit of each cell and the boundary between adjacent

cells.

A practical example of C1 radio criteria is shown in Figure 10

Radio Criteria

C1 = (A - Max(B,0))

A = Received Level Average - p1

B = p2 - Maximum RF Output P ower of the Mobile Station

p1 =rxLevelAccessMin(Min. received level at the MS required for accesssystem)

(RXP BTS -110..-105 -47dBm)

p2 =msTxPowerMaxCCH(Max. Tx power level an MS may use when accessystem)

(TXP BTS GSM900 5..33..43/2 33; GSM1800

0..30/2 30dB m)

rxLevelAccessMin -110 ... -47dBm 'RXP' (BTS)

msTxPowerM axCC H 0 30dBmGSM1800 (5 43dBmGSM900)'TXP' (BTS)

Parameter Value

Figure 10. Cell (Re-) Selection in Idle modeUsing C1 criterion

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A = 4 dB

B = 6 dB

C = 8 dB A B C 1 2

1

2

MS Moving

A B C

LA 1 LA2

cellReselectHysteresis 0 14 dB 'HYS' (BTS) 2dB steps MMLdef4dB

Parameter Value

Figure 11. Cell selection based on C1 in practice.

(There is a margin only between cells that belong to different location areas.)

4.2 C2 Criterion

The criterion C1 is used in Phase 1. C2 is used in GSM phase 2 with more

features, for use with two-layer microcell / macrocell architecture. C2 uses more

parameters:

Cell re-selection is needed if

P ath Loss criterion C1 < 0 for cell camped on ,for more than 5 seconds.

There is DL signalling failure

The cell camped on has become barred.

There is a better cell in terms of C2 criterion

A random access attempt is s till unsuccessful aftermaxNumberRetransmissionrepetitions.

MS will calculate the C 1 and C 2 for the serving cell, every 5 s

MS will calculate the C 1 and C 2 for the six best neighbour cells, every

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Figure 12. Cell Re-selection in Idle Mode

Using C2 Re-Selection Criterion (PH 2 MS)

The parametercellReselectParamInd (PI)(BTS)(Yes/No)becomes activated if

C2 parameters are sent to the Mobile (activates C2), and the parametercellBarQualify (QUA)(BTS)(Yes/No) controls whether the cell barring can be

overridden.

BCCH

BCCH

fast moving mobil

slow moving mobile

C2


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During time 0..19 sec (within the set penaltyTime):

C2 =C1+cellReselectOffset-temporaryOffset * H(penaltyTime-T)

C2 =32+20 -30*1

C2=22

=> C2 < C1, so MS will be kept in macro layer i.e. target cell (micro cell) is

NOT attractive.

1. During time 20.. (penaltyTime over):

C2=C1 +cellReselectOffset-temporaryOffset*H(penaltyTime-T)

C2=32+20-30*0

C2=52

=>C2 > C1, now target cell is very attractive and the idle mode MS will

camp on the microcell.

If the C2 > C1 before the penalty time is over, the cell reselection will be done

immediately.

If the C2 = C1 before the penalty time is over, the cell reselection will not be

done until the penalty time is expired.

Note that C2 is just meant for idle mode.

4.3 C31 & C32 Criteria

There are other criteria C31 and C32, which are used in GPRS. For further

information, see the module BSSPAR: GPRS & EGPRS (EDGE).

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5 Location Updates

A subscriber keeps moving from one place to another and the network must be

able to locate it for incoming calls. The transaction that enables the network tokeep track of the subscriber is called a Location Update. The mobile phone

constantly receives information sent by the network. This information includes

the VLR area in which the mobile is currently located. In order to keep track of

its location, the mobile stores the ID of the area in which it is currently

registered. Every time the network broadcasts the ID of the area, the mobile

compares this information to the area ID stored in its memory. When the two

IDs are no longer the same, the mobile sends the network a request, i.e. a

registration inquiry to the area it has just entered. The network receives the

request and registers the mobile in the new VLR area. Simultaneously, the

subscribers HLR is informed about the new VLR location and the data

concerning the subscriber is cleared from the previous VLR as shown below.

Figure 16. Elements involved in location update

Figure 17 Location update procedures

The VLR area is commonly referred to as a location area. As defined in GSM

specifications, it is the smallest area, into which a terminating call towards a

mobile subscriber will be paged. Also a location area is the area in which a

mobile needs not to update its location with its home location register.

Location update is performed in idle mode when the mobile is roaming into acell having a different location area code (LAC). In connected mode, the mobile

will update its location with the network as soon as it becomes idle again, i.e.

after call completion.

While handover boundaries affect only mobiles that are in connected mode,

location area boundaries affect all mobiles in the network, including the (many)

idle mobiles.

Location updating causes signalling and processing load across the entire

network hierarchy up to the mobiles HLR. In case of foreign roaming mobiles

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BSS MSC VLR HLR

REQUEST SUBSCRIBER INFO

ALL OK - HLR UPDATE

MS

LOCATION UPDATE REQUEST

SEND SUBSCRIBER ID

REQUEST SUBSCRIBER ID

SEND SUBSCRIBER INFO

AUTHENTICATION

AUTHENTICATION RESPONSE


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(tourists), this is often even international signalling traffic. Therefore planning

of location area boundaries should be considered with some thought, such as to

avoid oscillating location updates along a heavily frequented road.

Furthermore, different MSCs can not use the same LAC, otherwise the BSCwill not know to which MSC the mobile belongs.

In a location area, there is a trade-off between paging traffic and location

updating traffic. This means that concatenating e.g. a large city into a single

location area will avoid any location updating traffic, but on the other hand

causes a maximum in paging traffic, since every single terminating call within

the area is broadcast to every single cell in the area. (Even several times per call

attempt, depending on network parameters). This can cause significant traffic

loads within the network.

PagingLocUp

# of cells in Loc. area

signalling

traffic

optimum number

of cells in Loc. area

function of user density,

cell size, call arrival rate ...function of

user mobility

Figure 18. Trade-off between location update and paging traffic

Location updates are carried out every time a Mobile changes its location area

under one MSC, or between two different MSCs. When the location area

changes between two MSCs, the HLR is updated.

There are two types of location updates: automatic (random) location update

and periodic location update.

An automatic location update occurs when the Mobile is switched on if

IMSIAttachDetach (ATT)(BTS)parameter is used.

Periodic location updates carried out by the Mobile Station and is used to checkthat the location information in MSC/VLR is correct, because by error in the

MSC/VLR, the location information of Mobile Station can disappear. Periodic

location update is controlled by the timerPeriodicUpdateMS (PER)(BTS)

(0.0..25.5 hours) parameter.

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timerPeriodicUpdateMS 0.0 ... 25.5 hrs 'PER' (BTS) see note in dictiallowIMSIAttachDetach Yes/No 'ATT' (BTS)

Parameter Value

MS => MS C / VLR

Mobile Station switched ON

IMSI Attach / Detach

Same Location Area => No Location Update

Different Location Area => Location Update

Change of the Location Area

Location Area under the same MS C / VLR

Location Area under another MSC / VLR => HLR will be u

Service is rejected (MS unknown in VLR)

Time-P eriodic LU (MS -> MSC/VLR)

Figure 19. Location Updates

5.1 IMSI Attach & Detach

The IMSIAttachDetach (ATT)(BTS)(Yes/No) parameter is used to decreasesignalling load. The Mobile Station sends a message to the MSC notifying that

it is switching on or off. When the MSC knows that the Mobile Station is

switched off it does not try to page it, and useless paging is avoided.

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Search all the RF channels, take samples during3-5 s and calculate averages. And put them inascending order with respect to signal level.

Then tune to the strongest RF channel.

Search for the frequency correction burst in thatcarrier in order to verify if it is a BCC H carrier

Camp on the cell

T ry to synchronize to the carrier and readthe BC CH data

Is it a BCC Hcarrier?

Is it a correctPLMN ?

Is the cell ba rred?

Is C 1>0

Tune to the next highestRF channel which is not

tried before

No

No

NoNo

Y es

Y es

Y es

Y es

Figure 20. Normal Cell Selection

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6 Key Learning Points

During the idle mode, the MS has to perform a number of functions:

1. During Power On it has to check if it can access a PLMN and

cell.

2. It has to stay in contact with the BTS by decoding the BSIC

and listening to System Information messages.

3. It has to listen to BTS transmission for paging messages.

4. It has to monitor the status of radio links from various BTS

and choose the most appropriate BTS using C1 and C2 criteria.

5. It has to listen for cell broadcast short messages.

The parameters used by operators to control PLMN and cell selection and cell

reselection are:

notAllowedAccessClasses (ACC)(BTS)(0..9, 11..15) allows an

operator to define the MS access classes that are not allowed to access a

cell.

plmn-permitted (PLMN)(BTS)(0..7) which is broadcast on the

BCCH and is used by the mobile to report measurements of that PLMN

rxLevAccessMin (RXP)(BTS)(-110..-47 dBm) which describes the

minimum value of received field strength required by the MS to get any

service from the network in that cell, in idle mode.

cellBarred (BAR)(BTS)(Yes/No) parameter to keep a cell out of use

for testing purposes. An exception to a barred cell could be implemented

using parameteremergencyCallRestricted (EC)(BTS)(Yes/No).

cellReselectHysteresis (HYS)(BTS)(0..14 dB) is used as a margin in

the comparison of the field strength levels of the adjacent cells in different

Location Areas in idle mode. This margin prevents ping-pong location

updates, which will result in a waste of SDCCH capacity.

msTxPwrMaxCCH (TXP)(BTS)(13..43 dBm) tells the mobile the

maximum transmitting power when accessing the system.

cellReselectParamInd (PI)(BTS)(Yes/No) becomes activated if C2

parameters are sent to the Mobile.

cellBarQualify (QUA)(BTS)(Yes/No) controls if the cell barring can

be overridden or not.

penaltyTime (PET)(BTS)(20..640 s) describes the time delay before

the final comparison is made between two cells.

temporaryOffset (TEO)(BTS)(0..70 dB) describes how much field

strength could have been dropped during this penalty time.

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cellReselectOffset (REO)(BTS)(0..126 dB) describes an offset to

cell reselection.

Location information is updated by the MS to the network at a regular interval.

This is necessary for the paging to be carried out efficiently by the network.Each paging message is sent from every cell in a location area.

Location updates are carried out every time a Mobile changes its location area

under one MSC, or between two different MSCs. When the location area

changes between two MSCs, the HLR is updated. There are two types of

location updates: automatic location update and periodic location update.

Periodic location updates are carried out by the MS to update the location

information in the MSC/VLR. The interval is set by timerPeriodicUpdateMS

(PER)(BTS)(0.0..25.5 hours) parameter.

The IMSIAttachDetach (ATT)(BTS)(Yes/No) parameter is used to indicate

that an MS is switched off. The MSC does not try to page thus avoiding

unnecessary paging. An automatic location update occurs when the Mobile is

switched on ifIMSIAttachDetach (ATT)(BTS)parameter is used.

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7 Review Questions

Q1. Which of the following functions are not performed by an MS in idle

mode?

a) During Power On it has to check if it can access a PLMN and cell.

b) It has to stay in contact with the BTS.

c) Listen to BTS transmission for paging messages.

d) Monitor the status of radio links to various BTS and choose the most

appropriate BTS using C1 and C2 criteria.

e) Listen for cell broadcast short messages.

f) Listen to RACH messages from other mobiles.

The answers to choose for questions Q2-Q5 are given below a) - e):

a) notAllowedAccessClasses (ACC)(BTS)(0..9, 11..15)

b) plmn-permitted (PLMN)(BTS)(0..7)

c) rxLevAccessMin (RXP)(BTS)(-110..-47 dBm)

d) cellBarred (BAR)(BTS)(Yes/No)

e) cellReselectHysteresis (HYS)(BTS)(0..14 dB)

Q2. Which parameter is used as a margin to prevent ping-pong locationupdates?

Q3. Which parameter is used to keep a cell out of use for testing purposes?

Q4. Which parameter describes the minimum received field strength required

by an MS to get any service from the network in that cell in idle mode?

Q5. Which parameter allows an operator to define MS access classes that are

not allowed to access a cell?

Q6. Which parameter given below is used to tell the mobile the maximum

transmitting power when accessing the system.

a) msTxPwrMaxCCH (TXP)(BTS)(13..43 dBm)

b) cellReselectParamInd (PI)(BTS)(Yes/No)

c) cellBarQualify (QUA)(BTS)(Yes/No)

d) penaltyTime (PET)(BTS)(20..640 s)

e) temporaryOffset (TEO)(BTS)(0..70 dB).

f) cellReselectOffset (REO)(BTS)(0..126 dB)

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Idle Mode Operation

Q7. When are location updates carried out?

a) Every time an MS changes its location area under one MSC.

b) Every time an MS changes between two different MSCs.

c) On a periodic basis set by timerPeriodicUpdateMS (PER)(BTS)(0.0..25.5

hours) parameter.

d) All of the above.

Q8. Which of the following is true about IMSIAttachDetach (ATT)(BTS)

(Yes/No) parameter?

a) It is used to indicate that a BTS is switched on.

b) Its purpose is to avoiding unnecessary paging by the BSC.c) An automatic location update occurs when the Mobile is switched on

ifIMSIAttachDetach (ATT)(BTS)parameter is used.

d) It is used for periodic location updates carried out by the MS to

update location information in MSC/VLR.

e) All of the above.

bsspar-idle mode operation

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