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Planning and Design of

GSM/CDMA Networks 

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Planning and Design ofGSM/CDMA Networks

• A good geographical coverage is the basisfor providing network services.

•

Careful network planning is thus a priar!aspect of ipleenting GSM/CDMAnetworks

• Network planning is an ongoing process

re"uiring inputs fro a lot of copetenceareas# such as transission# accesss!stes# data counications# obileswitching# intelligent network# siteac"uisition# etc.

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GSM network architectureelements

• Mobile station $MS%

• &ase'station subs!ste $&SS%

• Network and Switching Subs!ste$NSS%

• (peration and Support Subs!ste

$(SS%

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Radio Frequenc S!ectrumPlanning

• GSM )** and +,** bands asstandard

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Radio Frequenc S!ectrumPlanning

 -he general process for Spectru assignentfollows the steps listed below.

+. Preparation of an ordered list of stations to be

assigned01. Assign 2rst fre"uenc! to 2rst station using

database lookup and anal!tical techni"ues toresolve interference probles0

3. Select ne4t station to be assigned using selectionprocedures. -hese include assignent grids#sub'allocation plans etc.0

5. Appl! fre"uenc!'selection ethod includingdatabase look up 0

6. epeat until all fre"uencies are assigned.

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Site "ngineering

• Collecting inforation regarding rules andregulations

•

7e! inforation concerning deograph!#incoe level# penetration forecast#geographical e4tension forecast# servicesto be supported# arket segentation# etc

• Availabilit! of leased lines# icrowave fre"availabilit!# re"uired connections withother s!stes# etc

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Site "ngineering

• Nubering# addressing and routingprinciples.

• -opographical aps.• 8n urban areas cells are usuall!

saller than in the countr!side.

• -he a4iu theoretical distancefro a &-S to the edge of the cell is36 7M.

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Network Design

Several re"uireents in the stages ofnetwork design.

+. Costs of building the network1. Capacit! of the network3. Coverage and location of the network

eleents

5. Ma4iu congestion allowed $grade ofservice%

6. 9ualit! of calls.

:. urther developent of the network

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Switching network !lanning

• -he switches need to bediensioned in accordance with the

estiated# needed capacit!.• -here is a need to create rules for

routing# protection# s!nchroni;ation

and switch anageent.• uture plan for e4pansion

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Cellular transmissionnetwork !lanning

• Cellular transission network refers to theusage of icrowave links in the GSM

network# for instance between the &-S andthe &SC.

•

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Congestion #andling

• Diensioning Cells

A cell is the basic =construction block>

of a GSM network. (ne cell is thegeographical area covered b! one&-S

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Dimensioning Cells

  8nputs for diensioning include

+. Geographical area to be covered

1. ?stiated tra@c in each region3. Miniu re"uireents of power in

each region and blocking criteria

5. Path loss6. re" band to be used and the fre"

reuse

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"rlangs

• ?rlangs is the easuring unit ofnetwork tra@c.

• (ne ?rlang e"uals the continuoususe of a obile device for one hour.

• orula

• ?rlangs $Calls per hour% B $avg. Conv. -ie%

  3:** Seconds

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Congestion #andling

• -he ore tra@c on availableresources# the ore chance that

there will be congestion.• Network planners should carefull!

anal!;e the tra@c volue on the

installed tra@c channel capacit!

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$oS

• 9ualit! of service e4perienced b! thesubscribers has to be high.

• -herefore it is iportant to reducethe nuber of dropped calls and thedegree of interference in the air in a

cost e@cient wa!.

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Network %!timi&ation

•  -he increase in the nuber of subscriberre"uires network e4pansion at the rightties and places.

•  -herefore e4cess network capacit! shouldbe avoided

• At the sae tie it is necessar! to oersu@cient grade of service to thesubscribers

• Present and future deand for basic andsuppleentar! services ust be satis2ed.

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Network %!timi&ation

• ence the network should be largeenough $su@cient coverage and

"ualit!% and sall enough $coste@cient% at the sae tie

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Radio Network PlanningProcess

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Radio N/w Planning Process

  Network Requirements

• Collection of 8/P paraeters such as

n/w re"uireents of capacit!#coverage and "ualit!

• -hese inputs are then used to ake

the theoretical coverage andcapacit! plans

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• Coverage E De2ning coverage areas#service probabilit! and related signal

strength• Capacit! E 8ncludes

•  the subscriber and tra@c pro2le in

the region and whole area• Availabilit! of fre" bands

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• re" planning ethods andinforation such as guard band and

fre" band division• 8nforation on radio access s!ste

and the antenna s!ste

perforance associated with it

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• Pre!lanning Process

• Site'Sur(e and site selection• C/) Analsis and Freq Plan

• Parameter !lanning

• Radio Network Plan