GBC 004 E1 0 Radio Parameters-50

8/13/2019 GBC 004 E1 0 Radio Parameters-50

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GBC_004_E1_0 Radio Parameters

Course Objectives:

Understand the meanings of various radio parameters

Master the impact of the settings of radio parameters

on radio network performance


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Contents

1 Network Idetit! Parameters""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""1

1.1 Cell Global Identity (CGI.......................................................................................................................1

1.1.1 !efinition..................................................................................................................................1

1.1." #ormat.......................................................................................................................................1

1.1.$ %etting and Influence................................................................................................................"

1.1.& 'recautions................................................................................................................................$

1." ase %tation Identity Code (%IC..........................................................................................................$

1.".1 !efinition..................................................................................................................................$

1."." #ormat.......................................................................................................................................)

1.".$ %etting and Influence................................................................................................................)

1.".& 'recautions................................................................................................................................*

# $!stem Cotro% Parameters"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""&

".1 CC+ Carrier ,ransmitted 'ower (%'-......................................................................................./

".1.1 !efinition................................................................................................................................../

".1." #ormat......................................................................................................................................./

".1.$ %etting and Influence................................................................................................................/

"." Common Control Channel Configuration (CCC+0C2#..................................................................../

".".1 !efinition................................................................................................................................../

"."." #ormat.......................................................................................................................................3

".".$ %etting and Influence................................................................................................................3

".$ 4ccess Grant locks (4G56...............................................................................................................3

".$.1 !efinition..................................................................................................................................3

".$." #ormat.......................................................................................................................................7

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".$.$ %etting and Influence................................................................................................................7

".& 'aging Channel Multiframes (%8'48M#M%...................................................................................19

".&.1 !efinition................................................................................................................................19

".&." #ormat.....................................................................................................................................19

".&.$ %etting and Influence..............................................................................................................11

".&.& 'recautions..............................................................................................................................1"

".) adio 5ink ,imeout (5,....................................................................................................................1"

".).1 !efinition................................................................................................................................1"

".)." #ormat.....................................................................................................................................1"

".).$ %etting and Influence..............................................................................................................1$

".).& 'recautions..............................................................................................................................1$

".* 2etwork Color Code 'ermitted (2CC':M......................................................................................1$

".*.1 !efinition................................................................................................................................1$

".*." #ormat.....................................................................................................................................1&

".*.$ %etting and Influence..............................................................................................................1&

".*.& 'recautions..............................................................................................................................1&

"./ Cell ar 4ccess (C4..........................................................................................................................1&

"./.1 !efinition................................................................................................................................1&

"./." #ormat.....................................................................................................................................1&

"./.$ %etting and Influence..............................................................................................................1)

"./.& 'recautions..............................................................................................................................1)

".3 Cell ar ;ualify (C;.........................................................................................................................1)

".3.1 !efinition................................................................................................................................1)

".3." #ormat.....................................................................................................................................1)

".3.$ %etting and Influence..............................................................................................................1*

".3.& 'recautions..............................................................................................................................1*

".7 4ccess Control 5evel (4C....................................................................................................................1*

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".7.1 !efinition................................................................................................................................1*

".7." #ormat.....................................................................................................................................1/

".7.$ %etting and Influence..............................................................................................................1/

".7.& 'recautions..............................................................................................................................13

".19 M4< :,42%.................................................................................................................................13

".19.1 !efinition..............................................................................................................................13

".19." #ormat...................................................................................................................................13

".19.$ %etting and Influence............................................................................................................17

".11 ,ransmission !istribution ,imeslots (,=0integer..............................................................................17

".11.1 !efinition..............................................................................................................................17

".11." #ormat..................................................................................................................................."9

".11.$ %etting and Influence............................................................................................................"9

".1" IM%I 4ttach>!etach 'ermission (4,,..............................................................................................."1

".1".1 !efinition.............................................................................................................................."1

".1"." #ormat...................................................................................................................................""

".1".$ %etting and Influence............................................................................................................""

".1".& 'recautions............................................................................................................................""

".1$ 'eriodical 5ocation Update ,imer (,$"1"........................................................................................."$

".1$.1 !efinition.............................................................................................................................."$

".1$." #ormat..................................................................................................................................."$

".1$.$ %etting and Influence............................................................................................................"$

".1$.& 'recautions............................................................................................................................"&

".1& Multi8band Indication (MC..........................................................................................................."&

".1&.1 !efinition.............................................................................................................................."&

".1&." #ormat..................................................................................................................................."&

".1&.$ %etting and Influence............................................................................................................")

".1) C54%%M46 :arly %ending Control (:C%C..................................................................................")

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".1).1 !efinition..............................................................................................................................")

".1)." #ormat..................................................................................................................................."*

".1).$ %etting and Influence............................................................................................................"*

".1).& 'recautions............................................................................................................................"*

".1* -ait Indication ,$1"".........................................................................................................................."*

".1*.1 !efinition.............................................................................................................................."*

".1*." #ormat..................................................................................................................................."/

".1*.$ %etting and Influence............................................................................................................"/

".1*.& 'recautions............................................................................................................................"/

' Ce%% $e%ectio Parameter""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""#(

$.1


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$.&.$ %etting and Influence..............................................................................................................$)

$.) Cell eselection 'arameter Indication ('I...........................................................................................$)

$.).1 !efinition................................................................................................................................$)

$.)." #ormat.....................................................................................................................................$)

$.).$ %etting and Influence..............................................................................................................$*

$.* 4dditional eselection 'arameter Indication (4C%.............................................................................$*

$.*.1 !efinition................................................................................................................................$*

$.*." #ormat.....................................................................................................................................$*

$.*.$ %etting and Influence..............................................................................................................$*

4 Network )uctio Parameters""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""'&

&.1 M% !ynamic 'ower Control %tatus.......................................................................................................$/

&.1.1 !efinition................................................................................................................................$/

&.1." #ormat.....................................................................................................................................$/

&.1.$ %etting and Influence..............................................................................................................$/

&." #reAuency +opping %tatus (+..............................................................................................................$/

&.".1 !efinition................................................................................................................................$/

&."." #ormat.....................................................................................................................................$/

&.".$ %etting and Influence..............................................................................................................$3

&.$ +opping %eAuence 2umber (+%2.......................................................................................................$3

&.$.1 !efinition................................................................................................................................$3

&.$." #ormat.....................................................................................................................................$3

&.$.$ %etting and Influence..............................................................................................................$3

&.& Mobile 4llocation Inde= ffset (M4I...............................................................................................$3

&.&.1 !efinition................................................................................................................................$3

&.&." #ormat.....................................................................................................................................$7

&.&.$ %etting and Influence..............................................................................................................$7

&.) !iscontinuous ,ransmission (!,


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&.).1 !efinition................................................................................................................................$7

&.)." #ormat.....................................................................................................................................$7

&.).$ %etting and Influence..............................................................................................................$7

&.* 4verage Cycle of Idle Channel Interference 5evel (I2,4?:..............................................................&9

&.*.1 !efinition................................................................................................................................&9

&.*." #ormat.....................................................................................................................................&9

&.*.$ %etting and Influence..............................................................................................................&9

&./ Interference and :dge (5IMI,n.........................................................................................................&9

&./.1 !efinition................................................................................................................................&9

&./." #ormat.....................................................................................................................................&9

&./.$ %etting and Influence..............................................................................................................&1

&./.& 'recautions..............................................................................................................................&1

&.3 2ew Cause Indication (2:CI...............................................................................................................&1

&.3.1 !efinition................................................................................................................................&1

&.3." #ormat.....................................................................................................................................&1

&.3.$ %etting and Influence..............................................................................................................&"

&.7 Call eestablishment 'ermission (:..................................................................................................&"

&.7.1 !efinition................................................................................................................................&"

&.7." #ormat.....................................................................................................................................&"

&.7.$ %etting and Influence..............................................................................................................&"

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1 Network Identity Parameters

1.1 Cell Global Identity (CGI)

1.1.1 Definition

4s a global cellular mobile communication system@ each G%M network of every

country or even each location area@ ,% and cell in each network have strict numbers@

to ensure that every cell worldwide has a uniAue number. ,he use of this numbering

scheme can achieve the following purposesB

It allows the M% to correctly identify the current network so that it can select the

network the subscriber (or operator wants to enter in any environment.

It allows the network to know the e=act location of a M% in real time so that the

network can normally connect various service reAuests to the M%.

It allows the M% to report the correct adacent cells to the network during calls@ so that

the network can maintain the calls through handover when necessary.

,he CGI is one of the maor network identity parameters.

1.1.2 Format

#ig. 1.1 81 shows the schematic diagram for the CGI.

#ig. 1.181 Composition of the CGI

,he CGI is composed of the 5ocation 4rea Identity (54I and Cell Identity (CI. ,he

54I further includes Mobile County Code (MCC@ Mobile 2etwork Code (M2C and

5ocation 4rea Code (54C@ as shown in #ig. 1.1 81. ,he CGI information is sent in

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the system messages broadcast by each cell. -hen a M% receives the system messages@

it e=tracts the CGI information inside and determine whether it can camp on the cell

according to the MCC and M2C indicated by the CGI. 4t the same time@ it checks

whether the current location area has changed to determine whether location update is

reAuired. !uring the location update process@ the M% reports the 54I information to the

network to allow the network to know the e=act cell where the M% is in. ,he format of

the CGI is MCC8M2C854C8CI.

MCCB It consists of three decimal numbers@ within the range of 999 D 777 (decimal. It

is &*9 for China.

M2CB It consists of two decimal numbers@ within the range of 99 D 77 (decimal.

54CB It is within the range of 1D*))$). ,he 54C is 99 for China Mobile@ and 91 for

China Unicom.

CI (Cell IdentityB It is within the range of 9 D *))$).

1.1.3 Settin and Infl!en"e

4s a global uniAue country identity standard@ the MCC resources are allocated and

managed by I,U in a unified manner. ,he mobile country code for China is &*9

(decimal.

,he M2C is usually allocated by the related telecom management authority of a

country in a unified manner. Currently@ there are two G%M networks in China@ which

are run by China ,elecom and China Unicom@ with the M2Cs to be 99 and 91

respectively.

:ach country has its specification for the coding method of 54C. China ,elecom has

specification for the coding method of 54C on its G%M network without e=ception

(#or details@ see the related specification for G%M published by the former Ministry of'osts and Communications of China. Usually@ in the earlier stage when a network is

built@ the allocation and coding of the 54C are determined and are seldom modified

during running.

,he siEe of 54C (that is@ the coverage of one 54C is a very key factor in the system.

Generally@ you should make the location area as large as possible.

#or the allocation of the CI@ there is no special restriction@ and it can be any value

within 9D*))$) (decimal. +owever@ you must ensure that not any two cells in one

location area have the same CI. Usually@ this has already been determined in the system

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" %ystem Control 'arameters

design of the network. Unless in special cases (for e=ample@ ,%s are added in the

system@ you should not modify the CI during the running of the system.

1.1.# Pre"a!tions

,he MCC should not be modified.

,he M2C should not be modified.

,he 54C should be set in strict accordance with the related specification of China

,elecom. 4void the cases where two or more location areas in the network (throughout

the country have the same 54C.

-hen you set the CI@ you must note that no two or more cells can have the same CI in

one location area.

1.2 $ase Station Identity Code ($SIC)

1.2.1 Definition

In the G%M system@ each ,% is allocated with one local color code@ known as %IC.

If a M% can receive the CC+ carriers of two cells at a location with the same channel

number@ the M% distinguishes them according to the %IC. In network planning@ the

CC+ carriers of the adacent cells should use different freAuencies in order to reduce

co8freAuency interference. n the other hand@ the characteristics of the cellular

communication system determine that the CC+ carriers are certain to have the

possibility of reuse. #or these cells using the same CC+ carrier freAuencies@ you must

ensure that they have different %ICs@ as shown in #ig. 1." 8".

#ig. 1."8" %chematic !iagram for %election of %IC

In the diagram@ the CC+ carriers of cells 4@ @ C@ !@ : and # have the same absolute

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GC099&0:109 adio 'arameters

channel numbers@ and other cells use different channel numbers as the CC+ carriers.

Usually@ cells 4@ @ C@ !@ : and # must use the same %IC. -hen the %IC resource is

insufficient@ different %ICs should be first ensured for the close cells. #or cell :@ if

there are not sufficient %IC resources@ different %ICs should be first used for cells !

and :@ and :@ and # and :@ while cells 4 and :@ and C and : can have the same

%ICs.

Its maor functions areB

1. 4fter a M% receives the %C+@ it believes that it has been synchroniEed with the

cell. +owever@ to correctly decode the information on the downlink public

signaling channel@ the M% also needs to know the ,raining %eAuence Code(,%C used by the signaling channel. 4ccording to the specification of G%M@ the

,%C is available in eight fi=ed formats@ which are represented with seAuence

numbers 9 D / respectively. ,he common signaling channel of each cell uses the

,%C determined by the CC of the cell. ,herefore@ one of the functions of the

%IC is to notify the M% of the ,%C used by the common signaling channel of

the current cell.

". %ince the %IC has participated in the decoding process of the andom 4ccess

Channel (4C+@ it can be used to prevent the ,% from sending the M% to the

4C+ of the adacent cell@ for misinterpretation as the access channel of the

current cell.

$. -hen the M% is in the connection mode (during calls@ it measures the CC+

carrier of the adacent cell and reports the results to the ,%@ according to the

specification of the adacent cell table on the CC+. 4t the same time@ the M%

must give the %IC of the carrier it has measured for each freAuency point in the

uplink measurement report. -hen in a special environment where the adacent

cells of one cell have two or more cells use the same CC+ carriers@ the ,%

can distinguish these cells based on the %IC@ to avoid incorrect handover@ or

even handover failure.

&. ,he M% must measure the signals of the adacent cells in the connection mode

(conversation process@ and reports the measurement results to the network.

%ince each measurement report sent by the M% only includes the contents of si=

adacent cells@ the M% must be controlled to report only the cells actually with

handover relationships with the current cells. ,he higher three bits in the %IC

(that is@ 2CC are used for the above purpose. ,he network operator can use the

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broadcast parameter Fallowed 2CC to control the M% to report the adacent

cells with the 2CCs in the allowed range.

1.2.2 Format

,he %IC consists of the 2etwork Color Code (2CC and ase %tation Color Code

(CC@ as shown in #ig. 1." 8$. ,he %IC is transmitted on the %ynchroniEation

Channel (%C+ of each cell.

#ig. 1."8$ Composition of the %IC

#ormat of the %ICB 2CC8CC

ange of the 2CCB 9 D /

ange of the CCB 9 D /


In many cases@ different G%M'5M2s use the same freAuency resources@ which@

however@ are somewhat independent in network planning. ,o ensure that the adacent

,%s with the same freAuency points have different %ICs in this case@ it is usually

specified that the adacent G%M'5M2s should select different 2CCs.

It is special in China. %trictly speaking@ the G%M network provided by China ,elecom

is a complete and independent G%M network. 4lthough China ,elecom has numerous

local mobile offices under it@ they all belong to one operator H China ,elecom.

+owever@ as China is a large country with a vast territory@ it is very difficult to

implement complete unified management. ,herefore@ the entire G%M network is

divided into parts managed by the mobile offices (or local organiEations in various

provinces and cities. n the other hand@ the mobile offices in various places are

independent of each other in network planning. ,o ensure that the ,%s with the same

CC+ freAuencies on the borders between various provinces and cities have different

%ICs@ the 2CCs of various provinces and cities in China should be managed by China

,elecom in a unified manner.

4s part of the %IC@ the CC is used to identify different ,%s with the same CC+

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carrier number in one G%M'5M2. Its value should meet the above reAuirement as far

as possible. In addition@ according to the G%M specification@ the ,%C of the CC+

carrier in a cell should be the same as the CC of the cell. Usually@ the manufacturer

should maintain such consistency.

1.2.# Pre"a!tions

It must be ensured that the adacent or nearby cells with the same CC+ carrier have

different %ICs. 'articularly@ when the adacent set of one cell has two more cells

having the same CC+ carriers@ it must be ensured that these two cells have different

%ICs. ou must pay special attention to the configuration of the cells on the borders

of various provinces and cities to avoid inter8cell handover failure.

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2 System Control Parameters

2.1 $CC% Carrier &ransmitted Power ($SP'$)

2.1.1 Definition

,he outputted power level of the ,% is usually adustable@ and different power levels

can be set for CC+ carriers and non8CC+ carriers. 'ower level means the outputted

power of the power amplifier. ,he %'- sets the transmitted power level of the

CC+ carrier of the ,%. ,his parameter has a huge impact on the coverage range of

the ,%.

2.1.2 Format

,he %'- is a decimal number@ in dm@ within the range of 9 D &*.


,he %'- has a huge impact on the actual coverage range of the cell. If thisparameter is set to too high a level@ the actual coverage range of the cell will become

larger@ causing great interference to the adacent cells. If this parameter is set to too

small a value@ gaps may occur between adacent cells@ causing Fblind areas. ,herefore@

the %'- should be strictly based on the design of network planning. nce set@ do

not change them in running unless absolutely necessary.

-hen the network is e=panded or due to other reasons (for e=ample@ the geographical

environment changes@ the parameter should be modified. efore and after the

parameter is modified@ you should perform complete field strength test on site@ and

adust the coverage range of the cell according to the actually conditions.

2.2 Common Control Cannel Confi!ration (CCC%*C+NF)

2.2.1 Definition

,he CCC+ can be borne by one physical channel or multiple physical channels@ and

the CCC+ and the %!CC+ can share one physical channel. ,he combination mode of

the CCC+ in a cell is determined by the CCC+0C2#.

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2.2.2 Format

,he CCC+0C2# consists of three bits@ as shown in ,able "." 81.

,able "."81 CCC+0C2# Code and Meaning

CCC+0C2#

CodeMeaning

2umber of CCC+ Message

locks in ne CC+ #rame

999CCC+ uses one basic physical channel@ not

shared with the %!CC+7

991CCC+ uses one basic physical channel@

shared with the %!CC+$

919CCC+ uses two basic physical channels@ not

shared with the %!CC+13

199CCC+ uses three basic physical channels@

not shared with the %!CC+"/

119CCC+ uses four basic physical channels@ not

shared with the %!CC+$*

thers eserved


,he configuration of the CCC+0C2# is determined by the operator according to thetraffic model of the cell@ usually in the system design stage. 4ccording to the common

e=perience@ when the number of ,


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2.3.2 Format

,he 4G56 means the blocks for the 4GC+ in the CCC+. Its meaning is shown in

,able ".$ 8".

,able ".$8" ,able of the 4G56

Combination between

CC+ and %!CC+4G56 Code

2umber of locks eserved for the 4GC+

in :ach CC+ Multi8frame

Combined

9 9

1 1

" "

2ot combined

9 9

1 1

" "

$ $

& &

) )

* *

/ /


,he 4G56 is a decimal number@ in the following rangeB

-hen CCC+ is not combined with %!CC+B 9 D /

-hen CCC+ is combined with %!CC+B 9 D "

,he default value is 1.

4fter the combination is determined between CCC+ and %!CC+@ the parameter

4G56 is actually the percentage for allocation between the 4GC+ and 'C+ in the

CCC+. ,he network operators can balance the load between the 4GC+ and 'C+ by

adusting this parameter. ou can observe the following principles when you are doing

thisB

1. ,he 4G56 should take the following valueB n the precondition that the

4GC+ is not overloaded@ the parameter should be kept as small as possible to

shorten the time the M% responds to the paging@ for higher service performance.

". Usually@ the 4G56 should be 1 (CCC+ and %!CC+ are combined@ " or $

(when CCC+ and %!CC+ are not combined.

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$. In the running network@ you can appropriately adust the 4G56 in measuring

the overload of the 4GC+.

2.# Pain Cannel /!ltiframes ($S0P,0/F/S)

2.#.1 Definition

4ccording to the G%M specification@ every M% subscriber (corresponding to each

IM%I belongs to one paging group. #or the calculation of the paging group@ see G%M

9).9". In each cell@ every paging group corresponds to one paging sub8channel@ and the

M% calculates its paging group according to its own IM%I@ and further the location of

the paging sub8channel belonging to the paging group. In an actual network@ a M% can

only Flisten to its paging sub8channel while ignoring the contents on other sub8

channels. -hen it is in other paging sub8channels@ it even turns off the power of some

its hardware devices to save power (that is@ the source of the !


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2.#.3 Settin and Infl!en"e

It is within the range of " D 7@ in multi8frames ()1 frames@ defaulted to ".

4ccording to the combination between CCC+ and %!CC+@ and the definitions of the

4G56 and %8'48M#M%@ you can calculate the number of paging sub8channels of

each cellB

1. -hen CCC+ and %!CC+ are combinedB ($84G56 J %8'48M#M%.

". -hen CCC+ and %!CC+ are not combinedB (784G56 J %8'48M#M%.

4ccording to the above analysis@ the larger the %8'48M#M%@ the more the paging

sub8channels of the cell@ and accordingly the lower the number of subscribers

belonging to each paging sub8channel. #or details@ see the calculation about the paging

group in the G%M 9).9". ,herefore@ the bearer capability of the paging channel

becomes more powerful. 2ote that the capacity of the paging channel has not increased

in theory@ but that the buffer of the paging messages is e=panded for each ,%@ for

evener transmission of paging messages in time and space. +owever@ the above

advantage is obtained at the cost of the average delay of the paging message on the

radio channel. In other words@ the larger the %8'48M#M% is@ the greater of the delay

of the paging messages in the space segment becomes@ and the average service

performance of the system decreases. bviously@ the %8'48M#M% is an important

parameter for network optimiEation.

-hen network operators set the %8'48M#M%@ they are recommended to observe the

following principlesB

1. ,he %8'48M#M% should be selected according to the principle that the

paging channels are not overloaded@ and the parameter should be kept as small

as possible under this precondition.

". ,he general recommendation is that you should set the %8'48M#M% to 3 or 7

(that is@ 3 or 7 multi8frames are used as the cycle of the paging group for the

areas where the paging channel is heavily loaded (usually the areas with heavy

traffic. ou should set the %8'48M#M% to * or / (that is@ * or / multi8frames

are used as the cycle of the paging group for the areas where the paging channel

is ordinarily loaded (usually the areas with appropriate traffic. ou should set

the %8'48M#M% to & or ) (that is@ & or ) multi8frames are used as the cycle

of the paging group for the areas where the paging channel is lightly loaded

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(usually the areas with small traffic.

$. In the running network@ the load of the paging channel should be measured atperiodical intervals to provide the data based on which the %8'48M#M% can

be appropriately adusted.

2.#.# Pre"a!tions

%ince any paging message in a location area (with the same 54C must be sent in all

the cells in the location area@ the paging channel capacity of each cell in the same

location area should be the same or close to each other as far as possible (meaning the

number of paging sub8channels calculated of each cell.

2. adio -ink &imeo!t (-&)

2..1 Definition

-hen the downlink voice (or data Auality of the M% degrades to the unacceptable

level during communication and cannot be improved by # power control or handover

(that is@ the so8called radio link failure@ the M% will either start call re8establishment or

forcedly clear the link. %ince the forced link clearing actually introduces one Fcall

drop process@ it must be ensured that the M% deems a downlink radio link failure only

when the communication Auality really becomes unacceptable (usually when the

subscribers have to hang up the call. #or this reason@ the G%M specification stipulates

that the M% must have a timer (%@ which is assigned with an initial value at the start of

the conversation@ that is@ the Fdownlink radio link timeout value. :very time the M%

fails to decode a correct %4CC+ message when it should receive the %4CC+@ the % is

decreased by 1. n the contrary@ every time the M% receives a correct %4CC+

message@ the % is increased by "@ but the % should not e=ceed the downlink radio link

timeout value. -hen the % reaches 9@ the M% will report the downlink radio link

failure.

2..2 Format

,he radio link timeout is a decimal number@ within the range of & D *&@ at the step of &@

defaulted to 1*.

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2..3 Settin and Infl!en"e

,he magnitude of the Fdownlink radio link timeout parameter may affect the call

interruption ratio and resource utiliEation of the network.

It is critical that the network operator should set this parameter to an appropriate value.

,he setting of the parameter is closely related to the actual application of the system.

Usually@ you can observe the following rulesB

1. In the areas with low traffic volume (usually remote areas@ the parameter should

be set to )" D *&.

In the areas with low traffic volume while a large coverage radius (suburbs or rural

areas@ this parameter should be set to $* D &3.

In the areas with heavy traffic (usually cities@ the parameter should be set to be "9 D

$".

In the areas with e=tremely heavy traffic (usually covered by micro cells@ the

parameter should be set to & D 1*.

#or the cells with obvious blind areas or the areas with severe call interruption during

moving@ the parameter should be increased appropriately.

2..# Pre"a!tions

n the ,% side@ there is also the means to monitor the radio link failure@ but the

monitoring method can be based on the uplink %4CC+ error or on the uplink reception

level and reception signal Auality. 4ccording to the G%M specification@ the radio link

monitoring mode on the ,% side is determined by the carrier@ and so is related to the

system the carrier has purchased. It should be noted that the uplink>downlink

monitoring standards must be on the same level.

2. Network Color Code Permitted (NCCP/)

2..1 Definition

In the connection mode (conversation process@ the M% needs to report to the ,% the

signal strength of the adacent cells it measures@ but each report can accommodate

those of up to si= adacent cells only. ,herefore@ it must be ensured that the M% reports

only the information of the cells that may become the target handover cells@ instead of

indiscriminately according to the signal level only. Usually@ the M% should be made not

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to report the cells of other G%M'5M2s. ,he above function can be implemented by

restricting the M% to measure only the cells whose 2CCs are some fi=ed values. ,he

2CC':M provides the 2CCs of the cells that the M% needs to measure.

,he %IC is transmitted continuously on the %C+ of each cell@ while the higher three

bits of the %IC represent the 2CC@ so the M% only needs to measure the 2CC of the

adacent cell and compare the result with the '5M2 parameter. If the 2CC is within

the set@ it reports the result to the ,%. therwise@ it discards the measurement results.

2..2 Format

,his parameter is a decimal number@ in the range of 9 D /. -hen the 2CC':M is set

to a value@ it means that the ,% needs to measure the cell whose 2CC is that value.


In China@ usually each area is assigned with one or multiple 2CCs@ and the 2CC':M

parameter of all the cells in the area must include the 2CC of the local area. therwise@

enormous inter8cell call drop and cell reselection failure may occur. In addition@ to

ensure that normal roaming between areas@ the edge cells of an area should include the

2CC of the adacent areas.

2..# Pre"a!tions

,he inappropriate setting of this parameter may be one of the maor reasons call drop.

2.4 Cell $ar ,""ess (C$,)

2.4.1 Definition

In the system message broadcast in each cell@ there is a bit used to indicate if the cell

allows the access of M%@ or@ cell bar access. ,he C parameter is used to indicate

whether the cell is set with the cell bar access.

2.4.2 Format

,he parameter is represented in a character string@ with the following valuesB

:%B :nable C4.

2B !isable C4.

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,he C4 bit is a parameter that the network operator can set. Usually@ all cells allow

M% access@ so the bit should be set to 2. +owever@ in special cases@ the carrier may

want to use a cell for handover only. %uch a need can be implemented by setting the

parameter to :%.

2.4.# Pre"a!tions

,he C4 is only applicable to some special cases@ and it should be set to 2 for

common cells.

2.5 Cell $ar 6!alify (C$6)

2.5.1 Definition

#or an area covered by cells in an overlay way@ according to the capacity of each cell@

traffic volume and the functionality difference of various cells@ the carrier usually

wants the M% to first select some cells in cell selection@ by setting priorities for the

cells. ,his function can be implemented by setting the C; parameter.

2.5.2 Format

,he C; is represented as a character string@ with the values of +IG+ and 5-@

defaulted to +IG+. ,he C; and the C4 together determine the priority status of a

cell@ as shown in ,able ".3 8&.

,able ".38& 'arameter C;

Cell ar ;ualify Cell ar 4ccess Cell %election 'riority Cell eselection %tatus

2 2 2ormal 2ormal

2 :% 'rohibited 'rohibited

:% 2 5ow 2ormal

:% :% 5ow 2ormal

In the above table@ there is one e=ception that the cell selection priority and cell

reselection status should be normal when the following conditions are met at the same

timeB

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1. ,he cell belongs to the home '5M2 of the M%.

". ,he M% is in the cell test operation mode.

$. ,he C4 of the cell is :%.

&. ,he C; is 2.

). ,he access control level 1) is disabled.


Usually@ the priority should be set to F2ormal@ that is@ C;K9@ for every cell. ut in

some cases@ such as micro cellular application@ dual8freAuency networking@ carriers

may hope that the M% preferably enters some types of cells first. ,hen@ the network

operator can set the priority of this cell type to F2ormal@ while setting the priorities of

other cells to F5ow.

!uring the cell selection process of the M%@ only when no appropriate cell with priority

of 2ormal e=ists (by appropriate@ it means that various parameters meet the conditions

of cell selection@ that is@ C1L9 and the cell does not prohibit access@ will the cells with

lower priorities be selected.

2.5.# Pre"a!tions

2ote that when you optimiEe the network by using the cell priorities@ the C; affects

only cell selection@ while having no impact on cell reselection. ,herefore@ to achieve

the obective@ you must use the C; and C" in combination.

2.7 ,""ess Control -e8el (,C)

2.7.1 Definition

In some special cases@ the carrier wants to prohibit all or some M%s from initiating

access reAuests or paging response reAuests in some special areas. for e=ample@ when

emergencies occur in some areas or one G%M '5M2 has critical faults. ,herefore@ the

G%M specification (9".11 stipulates that one access level should be allocated to each

G%M subscriber (common subscriber usually. ,he access level is available in 19

brackets from 9 to 7@ which are stored in the %IM cards of the mobile subscribers. #or

some special subscribers@ the G%M specification reserves five special access levels@ 11

to 1). ,hese levels usually have higher access priorities. ,hese special subscribers can

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have one or multiple access levels at the same time (11 D 1)@ which are also stored in

the %IM cards of the subscribers. ,he access levels are allocated as belowB

5evels 9 D 7B common subscribers

5evel 11B for management of the '5M2

5evel 1"B for use by security departments

5evel 1$B for pubic utilities (water@ gas and so on

5evel 1&B emergency services

5evel 1)B '5M2 employees

%ubscribers with access levels 9 D7 have access to both the home '5M2s and visited

'5M2s. %ubscribers with access levels 11 and 1) have access to only the home

'5M2s. %ubscribers with access levels of 1"@ 1$ and 1& have access within the country

of the home '5M2.

%ubscribers with access levels 11 D 1) have higher access priorities than subscribers

with access levels 9 D 7@ but within access levels 9D7 and access levels 11 D 1)@ the

magnitudes of the numbers do not represent difference in priorities.

2.7.2 Format

,he access level control parameter consists of 1* bits. If one bit is 9@ it means that the

M%s with the appropriate access level are not allowed to access the current cell.

therwise@ access is allowed.


C9 D C1) (e=cluding C19 can be set by the network operator@ and should usually be

set to 1. 4ppropriately setting these bits have very important influence for network

optimiEation@ in the following aspectsB

1. !uring the installation and commissioning of the ,% or during the

maintenance and test of some cells@ the operator can set C9 D C7 to 9@ to

forcedly prohibit the access of common subscribers@ thus reducing the

unnecessary impact on the installation and maintenance.

". #or cells with heavy traffic@ congestion may occur during busy hours@ with the

symptoms of increased 4C+ conflicts@ 4GC+ flow overload@ and 4bis

interface flow overload. In the G%M specification@ there are many means to

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solve overload and congestion@ but most of them will affect the utiliEation of the

eAuipment resource. ,he network operator can control the traffic volume in a

cell by setting the appropriate access control parameter (C9 D C1). #or

e=ample@ when a cell e=periences traffic overload or congestion@ you can set Ci

to 9 to prohibit the M%s of the appropriate access level from accessing the

current cell (,he change of the Ci does not affect the M%s in communication@ to

reduce the traffic volume in the cell. ,he disadvantage of the above mode is that

some M%s are treated Funfairly. ,o solve this problem@ you can change the

values of C9 D C7 of the cell in cycle@ at an interval of five minutes@ for

e=ample@ to access the M%s with even or odd levels alternately.

2.7.# Pre"a!tions

,he value of the Ci does not affect the cell selection and reselection process of the M%.

2.19 /,: &,NS

2.19.1 Definition

-hen a M% starts the immediate assignment process (such as the M% needs to update

the location@ originate a call or respond to paging@ it will send the Fchannel reAuest

message over the 4C+ channel to the network. ecause the 4C+ is an 45+

channel@ the network allows the M% to send multiple channel reAuest messages before

receiving the immediate assignment message@ to improve the success ratio of M%

access. ,he M4< :,42% is determined by the network.

2.19.2 Format

,he M4< :,42% is represented as a decimal number@ which can be 1@ "@ & or /@ as

shown in ,able ".19 8).

,able ".198) Codes of the M4< :,42% (M

M Code M4< :,42%

99 1

91 "

19 &

11 /

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,he M4< :,42% of each cell in the network can be set by the network operator.

Usually@ the larger the M4< :,42%@ the higher the call attempt success ratio and

call completion ratio@ but also the higher the load on the 4C+@ CC+ and %!CC+. In

the cells with heavy traffic@ if the M4< :,42% is too high@ overload and

congestion of radio channels may occur@ thus greatly reducing the call completion ratio

and radio resource utiliEation. n the contrary@ if the M4< :,42% is too low@ the

call attempt success ratio of the M% will decrease@ thus affecting the call completion

ratio of the network. ,herefore@ reasonably setting the M4< :,42% of each cell is

an important means to fully e=ploit the network radio resources and improve the call

completion ratio. ou can observe the following principles in setting the M4orary +ffset (&+) andPenalty &ime (P&)

3.3.1 Definition

4fter a M% selects a cell@ the M% will stay in the selected cell as long as no maor

changes occur to various conditions. 4t the same time@ the M% starts to measure the

signal level of the CC+ carrier of the adacent cells@ records the si= adacent cells

with the highest signal levels@ and e=tracts from them the various system messages and

control messages of each adacent cell. -hen the appropriate conditions are met@ the

M% will switch from the current cell to another cell@ a process known as cell

reselection. %uch appropriate conditions include multiple factors@ including cell

priority@ and whether the cell is prohibited from access. 4mong them@ an important

factor is the Auality of the radio channel. -hen the signal Auality of the adacent cell

e=ceeds that of the current cell@ cell reselection is triggered. #or cell reselection@ the

channel Auality criterion is determined by the C" parameter@ which is calculated

according to the following formulaB

C" K C1 C:550:%:5:C,0##%:, 8 ,:M'40##%:, J +

(':245,0,IM:8,

-hen the ':245,0,IM: is not eAual to $1P

C" K C1 8 C:550:%:5:C,0##%:,

-hen the ':245,0,IM: is eAual to $1P

-hereB

1. + (= K 9@ when =Q9P + (= K 1@ when =9

". , is a timer with the initial value of 9. -hen a cell is recorded on the list of the

si= adacent cells with the highest signal level by the M%@ the timer , of that cell

starts to count to the accuracy of a ,!M4 frame (about &.*" ms. -hen the cell

is deleted from the list of the si= adacent cells with the highest signal level by

the M%@ the corresponding timer , will be reset.

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$. ,he C:550:%:5:C,0##%:, is used to correct the cell reselection

parameter C".

&. ,he function of the ,:M'40##%:, is to give the C" a negative

correction during the period between when the timer , starts and when it reaches

the specified value of the ':245,0,IM:.

). ,he ':245,0,IM: is the time that the ,:M'40##%:, works on

the C" parameter. +owever@ the all 1Rs code of the ':245,0,IM: is reserved

for the C:550:%:5:C,0##%:, to change the sign for the effect on the C".

*. ,he C:550:%:5:C,0##%:,@ ,:M'40##%:, and

':245,0,IM: are cell reselection parameters. -hen the cell reselection

parameter indication ('I is 1@ they are broadcast on the CC+ of the cell. If

'IK9@ the M% believes that they are all 9@ and hence C"KC1.

If the M% finds that the C" value of an adacent cell (the current cell is in the same

location area e=ceeds the C" value of the current cell and this continues for more than

five minutes@ then the M% will start the cell reselection process to enter the adacent

cell. If the M% finds that a cell in another location area different from the current cell

has a C" value e=ceeding that of the current value plus the cell selection hysteresis and

this continues for more than five minutes@ then the M% will start the cell reselection

process to enter the adacent cell. +owever@ it must be noted that the cell reselection

initiated by the C" parameter should be at an interval of at least 1) seconds@ to avoid

freAuent cell reselection of the M%.

,he cell reselection initiated by the cell channel Auality uses the C" parameter as the

criterion. ,he C" is based on the C1 parameter@ with some manual offset parameters

incorporated. ,he manual effect is incorporated to encourage the M% to first enter some

cells or prevent it from entering them. Usually@ such means are used to balance the

traffic volume in the network.

In addition to the C1 that affects the C" parameter@ there are the following three factorsB

C:550:%:5:C,0##%:, (C@ ,:M'40##%:, (, and

':245,0,IM: (',.

,he C is a value of Auantity@ meaning the manual correction value to the C". ,he

, means the temporary correction value for the C". y temporary@ it means that the

value only takes effect on the C" within a certain period@ which is determined by the

', parameter.

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3.3.2 Format

,he C is a decimal number@ in d@ within the range of 9 D *$@ meaning 9 D 1"* d@

at the step of " d. Its default value is 9.

,he , is a decimal number@ in d@ within the range of 9 D /@ meaning 9 D /9 d@ at

the step of 19 d@ where /9 means infinite. Its default value is 9.

,he ', is a decimal number@ in seconds@ within the range of 9 D $1@ meaning "9 D *"9

seconds for 9 D $9@ and at the step of "9 seconds. ,he value of $1 is reserved to change

the direction of effect that the C works on the C" parameter. Its default value is 9.

3.3.3 Pre"a!tionsou should pay attention to the following problems when you adust the above

parametersB

1. In whatever conditions@ you are not recommended to set the C to a value

higher than ")d@ because the too high C may cause instability to the

network.

". ,he above parameters are set on the basis of each cell. +owever@ due to the

nature of the C" parameter and its close relationship with the adacent cell@ you

should pay attention to the relationship between the adacent cells when you set

these parameters.

3.# /S*&:P'*/,:*CC%

3.#.1 Definition

!uring the communication between the M% and the ,%@ the transmitted power of the

M% is controlled by the network. ,he network sets the power of the M% by using the

'ower Command@ which is transmitted over the %4CC+. ,he M% must e=tract the

power control header from the downlink %4CC+ and takes the specified transmitted

power as the output power. If the power level of the M% cannot output the power value@

it will output the closest transmitted power that can be outputted.

ecause the %4CC+ is the channel associated signaling@ it must be used in

combination with other channels such as %!CC+ and ,C+. ,herefore@ the power

control of the network over the M% actually starts when the M% receives the %4CC+.

,he power of the M% before it receives the %4CC+ (the power used to send the

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4C+ is determined by the ma=imum power level of the control channel

(M%0,


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parameters from the system messages broadcast by the cell to calculate the value C" as

the cell reselection criterion. F9 indicates that the M% should use C1 as the criterion

for cell reselection (it is eAuivalent that C"KC1.


If C" is used as the cell reselection parameter@ the 'I must be set to 1. therwise@ it

must be set to 9.

3. ,dditional esele"tion Parameter Indi"ation (,CS)

3..1 Definition

,he 4C% is used to notify a M% whether to use C".

3..2 Format

,he 4C% consists of only one bit@ whose meaning is described as belowB

1. In system message $@ the 4C% is meaningless@ and the eAuipment manufacturer

should set the bit to 9.

". In system message &@ when 4C%K9@ it means that if system message & has any

remaining byte@ the M% e=tracts from it the 'I parameter about cell reselection

and the related parameters for calculating C". -hen 4C%K1@ it means that the

M% e=tracts from the remaining byte of system messages / or 3 the 'I parameter

about cell reselection and the related parameters for calculating C".


In the configuration of common cells@ system messages / and 3 are seldom used@ so the

4C% should usually be set to 9.

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# Network F!n"tion Parameters

#.1 /S Dynami" Power Control Stat!s

#.1.1 Definition

,o minimiEe the interference of the radio space at a certain communication Auality@ the

G%M system provides the power control capability for the M%. -hether power control

is used can be determined by setting the FM% dynamic power control status parameter.

#.1.2 Format

,his parameter is an identifier@ which can be 4C,I?: or I24C,I?:@ with the

following meaningB

4C,I?:B ,he M% uses dynamic power control.

I24C,I?:B ,he M% does not use dynamic power control.

#.1.3 Settin and Infl!en"e

M% dynamic power control can reduce the radio interference in the network and

increase the service Auality of the network@ so usually the M% power control should be

used@ by setting the parameter to 4C,I?:.

#.2 FreA!en"y %o>>in Stat!s (%)

#.2.1 Definition

4ccording to the G%M specification@ the G%M radio eAuipment should support the

freAuency hopping function. ,heoretical analysis shows that freAuency hopping can

improve the freAuency spectrum environment in the space and elevate the

communication Auality of the entire network. -hether freAuency hopping is used in the

network can be implemented by setting the FfreAuency hopping status (+ parameter.

#.2.2 Format

,his parameter is represented by one bit@ where 9 means that freAuency hopping is

disabled@ and 1 means that freAuency hopping is enabled.

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-hen conditions are mature@ the operation department is recommended to use the

freAuency hopping function.

#.3 %o>>in SeA!en"e N!mber (%SN)

#.3.1 Definition

In the G%M system@ the set of carriers used by each cell is e=pressed as FCell

4llocation (C4@ written as N9@ 1@ S@ 2 81O@ where i means the absolute

freAuency number. #or each communication process@ the set of carriers used by the ,s

and M% is e=pressed as FMobile 4llocation (C4@ written as NM 9@ M1@ S@ M281O@

where Mi means the absolute freAuency number. bviously@ the M4 is a subset of the

C4.

!uring the communication process@ the carrier number used on the air interface is an

element in the M4 set. ,he variable FMobile 4llocation Inde= (M4I is used to

determine an e=act element in the M4 set@ where 9 M 4 I n 8 1 . 4ccording to the

freAuency hopping algorithm given in G%M 9).9"@ the M4I is the function of the

,!M4 #2 (#2@ +%2@ and M4I. -here@ the +%2 determines the track for the

running of the freAuency point during freAuency hopping. ,hat the adacent uses thecells with the same M4 and takes different +%2s can ensure that the utiliEation of

freAuencies is not in conflict during the freAuency hopping process.

#.3.2 Format

,his parameter is a decimal number@ in the range of 9 D *$@ whereB

9B cyclic freAuency hopping

1D*$B pseudo random freAuency hopping


,he cells using freAuency hopping can have any +%2s@ but the cells in the same

freAuency group must use different +%2s.

#.# /obile ,llo"ation Inde; +ffset (/,I+)

#.#.1 Definition

!uring the communication process@ the carrier number used on the air interface is an

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element in the M4 set. ,he variable FMobile 4llocation Inde= (M4I is used to

determine an e=act element in the M4 set@ where 9 M 4 I n 8 1 . 4ccording to the

freAuency hopping algorithm given in G%M 9).9"@ the M4I is the function of the

,!M4 #2 (#2@ +%2@ and M4I. -here@ the M4I is an initial offset of the M4I@

used to prevent multiple channels from seiEing the same carrier at the same time.

#.#.2 Format

,his parameter is a decimal number@ in the range of 9 D *$.

#.#.3 Settin and Infl!en"e

It should be noted that the channels on the same carrier in a cell should have the same

M4I. In addition@ the different cells with the same group of M4 should also have the

same M4I.

#. Dis"ontin!o!s &ransmission (D&:)

#..1 Definition

!iscontinuous transmission (!,


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#. ,8erae Cy"le of Idle Cannel Interferen"e -e8el (IN&,?)

#..1 Definition

4ccording to G%M 9).93@ the ,% must measure the uplink interference level of all

idle channels@ to provide the basis for management and allocation of radio resources.

!ue to the randomness of the radio channel interference@ the ,% must average the

measured uplink interference levels within the specified period@ and this average cycle

is determined by the I2,4?: parameter.

#..2 Format

,his parameter is a decimal number@ in %4CC+ multi8frames@ within the range of 1 D $1.

#..3 Settin and Infl!en"e

,he smaller the I2,4?:@ the more real8time the measurement@ while the heavier the

flow on the 4bis interface. Usually@ it is recommended to be * D 19. If the 4bis

signaling flow load is heavy@ the I2,4?: value can be appropriately increased.

#.4 Interferen"e $and de (-I/I&n)

#.4.1 Definition

4ccording to G%M 9).93@ the ,% must measure the uplink interference level of all

idle channels@ to provide the basis for management and allocation of radio resources. In

addition@ the ,% must analyEe the measurement results and divide the interference

levels into five grades to be reported to the %C. -hen the M%C inAuires@ the %C

reports such information to the M%C. ,he division of the five interference grades

(interference band can be set by the operator on the man8machine interface. ,he

5IMI,n parameter determines the edge for dividing the five interference bands.

#.4.2 Format

,his parameter is a decimal number@ within the range of 9 D *"@ with the meaning

shown in ,able &./ 83B

,able &./83 Interference and

9 Q8119dm

1 8119dm D 8197dm8119 dm D 8197 dm

" 8197dm D 8193dm8197 dm D 8193 dm

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... ...

*1 8)9dm D 8&7dm8)9 dm D 8&7 dm

*" 8&7dm D 8&3dm8&7 dm D 8&3 dm

!efault ?alueB

5IMI,1B &P 5IMI,"B 3P 5IMI,$B 1)P 5IMI,&B ")


,he division of the interference band should be conducive to the description of the

interference in the system. Usually@ you are recommended to accept the system

defaults. Generally@ the idle channels have a small interference level@ so the values of

the 5IMI,1 D & should be small. -hen the obvious large interference occurs in the

system@ you can appropriately increase the 5IMI,1 D & to learn e=actly the value of the

interference.

#.4.# Pre"a!tions

-hen you are setting them@ you must pay attention to the relationships among 5IMI,1

D 5IMI,&@ ensuringB

5IMI,1 T 5IMI," T 5IMI,$ T 5IMI,&

#.5 New Ca!se Indi"ation (NCI)

#.5.1 Definition

4ccording to the G%M specification@ the traffic channels in the G%M system include

full8rate and half8rate channels. ,he common G%M systems all support full8rate

channels@ while whether the network support half8rate services is determined by the

network operation department. ,he 2:CI parameter is used to notify the M% if the areasupports the half8rate services.

#.5.2 Format

,he 2:CI is a decimal number@ within the range of 9 D 1@ with the meaning described

as belowB

1. -hen the 2:CI is 9@ it means that the cell does not support the access of half8

rate services.

". -hen the 2:CI is 1@ it means that the cell supports the access of half8rate

41


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services.



ecause the G%M network of China Mobile currently does not offer half8rate services@

the 2:CI should be set to 9.

#.7 Call eestablisment Permission ()

#.7.1 Definition

In the case of call drop due to radio link failure resulting from abrupt interference or

blind areas caused by high buildings@ the M% can initiate the cell reestablishment

process to recover the call@ but the network has the right to determine whether to allow

such call reestablishment.

#.7.2 Format

9 means that the cell allows call reestablishment and 1 means that the cell does not

allow call reestablishment.


In a certain environment@ a M% will e=perience a call drop when it passes a blind spot.

If call reestablishment is allowed@ the average call drop ratio can be reduced. +owever@

the call reestablishment process takes a long time@ and most subscribers have hanged

up before such reestablishment is completed. ,herefore@ reestablishment does not

achieve its purpose@ while many radio resources are wasted. ,herefore@ you are

recommended to disable call reestablishment on the network e=cept for a few particular

cells.

Documents

GBC 004 E1 0 Radio Parameters-50