KPI ANALYSIS_Mitesh.ppt

KPI ANALYSISREASONS AND SOLUTIONS

Some Relations-1-One BSC=6 BCSU (Base control signaling unit).One BCSU = support 110 TRX. 1 TRX= 8 time slots.Total no. of TRX = 110 *6=660 TRX in single BSCOne BSC = One LACOne BSC= 660* 8 = time slots but if dual rate is implemented that it consider as two slots.One BSC= two Lac also but for city one LAC b/c it effects SD blocking and LAC updation on that channel.

Some Relations-2-One BSC= 1 to 248 BCF.

One BSC= 1 to 248 BTS

One BTS means = one sector of any configuration

One BCF means= one site of three or four sector

BCF= Base control function.

BTS= Base transceiver system.

NSEI= is hardware and software device which supports the GPRS in n/w

Some Relations-3-One NSEI= supports 64 BTS and 128 TRX if any one of them is full then we can assign second NSEI port in same BSC1TRX=117 subscriber1 subscriber=25 m erlangs (TCH)1 subscriber=.004 m erlangs(SD)1 TRX=2.94 erlang(2% GOS )2 TRX=8.2 erlang(2% GOS )3 TRX=14.6 erlang(2% GOS )4 TRX=21.2 erlang(2% GOS )If BSC 3VI, OSS is 4 and System is S11 then max capacity of BSC is 660 TRXs.If OSS 4.2 and system S12 is using then max capacity of BSC will be 2000TRXs

KPIs to be monitoredSD BlockingSD DropTCH BlockingTCH AssignmentTCH DropHOSR

KPIs to be monitored

ParameterShowcase ThresholdNon-Showcase ThresholdSD Blocking0.250.5SD Drop1.21.7TCH Blocking0.50.5TCH Assignment98.598TCH Drop1.53HOSR9592

Get ServiceGet SDCCHEstablish SD ChannelEst. TCHConn.Call PhoneRef. PhoneSD BlkingSDCCH SeizerTCH BlkingCSSR or TCH AssignmentCall EstablishmentCall completion Rate (TCH Drop call)

What is Dropped Call?All cell resources are available but calls are failing, then we have a call drop scenario. This could be caused by software errors, congestion, C7 link failures,HW problems or many other reasons.

If a call is abnormally disconnected, a Clear Request is sent to the MSC .If the Call is disconnected in a normal Fashion then Clear Message with cause code Call Control is sent. It is important to establish what types of calls are failing, and over what percentage of the network it is occurring.

SDCCH CHANNEL :

SDCCH is a dedicated channel which is using for LAC updation, Call setup, SMS in idle mode. It works in UL & DL.

SD Blocking:SD blocking means that you are not getting SD resource for the call origination. When MS connects with NW then RACH and AGCH are provided. After AGCH,SDCCH is provided but if SDCCH is not provided at this time due some problems or due to unavailable of SD by BSC ,its called as SD Blocking. There are no of reasons for that.If such a case arises the customer will not be able to originate any call.

Difference Between Blocking and Congestion:It is very important to know difference between blocking and congestion. Some people think that both are same, but they differ from each other. If all the SD resources are full and not available for SD assign then its come into congestion. If at a particular time call is attempted and it fails then it known as Blocking.

Reasons for SD Blocking:Some of them are-LAC boundary.HW Prob.

Solutions for removal of SD Blocking:Here are some steps by which we can reduce SD Blocking-Check the No. of SDCCH channel Available, if less then increase SD channel taking care that there is no TCH Blocking.Check LAC boundary, If location update is more then change the LAC of that site and set C2 and HYS.Use of Dynamic SDCCH (It is a BSC parameter and will be applied on whole BTS).Hardware check / shift SD to new time slotSome times BMA and HYS parameters are useful to remove SD Blocking.

Usefull Reports For SD Blocking:Use 182 to analyses SD Blocking reasons.130 for SD congestion.

SD Drop:As per diagram shows when we assigned SD for call origination and at that time due to some problem or any mismatch comes by which SD loss occurs, it is called as SD Drop.It occurs between allocation of SD and before TCH allocation. Sometimes SD drop occurs because queuing is not activated in the system. If SD drop is high plz look on parameters like- overshooting , shift the SD time slot , may be hardware issue, interference, change the values of RXP, PMAX, may be issue of uplink or downlink issue in that cells for UL put a TMA in that cell and for DL provide tilt ,re orient that antenna

If SD Drop is high:If SD drop is high plz look on parameters like- Overshooting Shift the SD time slot Hardware issueInterference Change the values of RXP PMAX It may be uplink or downlink issue in which cells for UL put a TMA in that cell and for DL provide tilt Re orient that antenna

Reasons of SD Drop:Hardware Fault.Interference.MAIO mismatch.Bad Coverage.High TR Fail.Outage.Overshooting.Abis Drop.High Path Loss.Wrong Parameter Planning.Due to ICM Band(CDMA)High LAPD UtilizationHeavy blocking and DR feature being used extensively

Solutions for removal of SD Drop:Interference:Check the BCCH Plan (C/I or C/A).Co-BSIC & Co BCCH.Use latest ND 111 and MapInfo to find out proper frequency to reduce interference.Arrange Drive Test:The best way to find the real issues for Interference makes DT.Check interference by Interference scanning.Check clean BCCH by frequency scanning.

Overshooting:LAC Planning.If a cell is picking call from long distance, Check the sample log according to TA.Cell orientation need to be defined according to clutter.Mount position Effective Tilt.

ContHigh TR Fail:Check and clear TR fail from OSS end.

Bad Coverage:If the drop call is due to low signal strength uplink, check the receive path of this particular TRX. Check receiver sensitivity, VSWR, feeder connection and etc. Drops due to Low Signal Strength.

If the drop call reason is due to low signal strength downlink, then, check the transmit path. Check cards, feeder and etc.

Use MapInfo or Google Earth to find location of sites.

Cont..

High LAPD Utilization:Check LAPD util report from OSS, and define 32 kbps signaling instead of 16kbps

Hardware Fault:Check Alarms.TRX condition.Check Path Imbalance.VSWR of the Cell.Connector Connection.Some times you will find issues on BCCH TRX.In this case BCCH shift from one to other TRX will reduce SD drop.

Cont

Due to ICM Band(CDMA):Some time SD drops takes place due to near sites of CDMA.

Check the ICM band value of that site.

Use BPF (Band pass filter).

Use the spectrum analyzer.

Cont..

Check for parameter:Check the Timer T 3101

Check the Timer T 200(20ms)

T11 Expired(10 s)

MAIO check.

Useful Reports for SD Drop:Use report ZEOL to find the alarms.Use 208 for Path loss analysis.Use 196 for UL-DL Interference.Use 163 report for SD drop.Use report 216 for detail SD Drop.232 report for TA report.62 for Adj cell having same or adj freq.ND 111 for freq plan.204 for BTS and cell report.

TIMER T3101The MS requests for resources by sending channel request on RACH.The BSS allocates a SDCCH, if available, and sends a IMMEDIATE ASSIGNMENT message on the downlink. This message contains the details of allocated SDCCH, TSC , TA etc.As soon as the BSS allocates and sends message on the AGCH, it starts a timer T3101.The MS logs on the SDCCH and sends a message on the UPLINK.As soon as the BSS receives this message the timer T3101 is stopped.If no message is received by the BSS from the MS and timer T3101 expires, then the BSS releases the allocated SDCCH resource.This timer is set in millisecs.

TIMER T3101Successful SDCCH AccessUnsuccessful SDCCH Access

T3101

MS

CELL

RACH

CL2I

IF MS SENDS CL2I ON SDCCH STOP TIMER T3101

IMMEDIATE ASSIGNMENT(AGCH)

SDCCH ALLOCATED START TIMER T3101

MS

CELL

RACH


SDCCH ALLOCATED

START TIMER T3101

IF T3101 EXPIRES AND BSS DOES NOT RECEIVE CL2I ON SDCCHRELEASE ALLOCATED RESOURCES

Sheet7

FACTORSMACROMICROMULTILAYER

NUMBER OF SITES4(12 CELLS)24(24 CELLS)12+24 = 36

AREA CONSIDERED3.5 km23.5 km23.5 km2

NUMBER OF CARRIERS / CELL222

ERLANG / SUBSCRIBER25mE25mE25mE

GOS2%2%2%

ERLANGS / CELL FOR GIVEN GOS8.28.28.2

TOTAL ERLANGS GENERATED FOR GIVEN AREA98.4196.8295.2

NUMBER OF SUBSC SUPPORTED3936787211808

ERLANGS / km228.1156.2384.34

SPECTRUM AVAILABLE IN BOTH THE CASES IS 4.8MHZ

ERLANG B TABLE USED FOR CALCULATING ERLANGS FOR GIVEN GOS

Sheet1 (2)

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

BCCH

AGCH

25

26

27

28

29

30

31

32

Sheet1

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

Sheet4

System InformationBCCH Multiframe

10

21

32 and 6

43 and 7

124123122121cch_confPhysical ChannelsCombinedNo of CCH

016015014013012011010009

008007006005004003002001

87654321

Octet A

1111Octet BBCD

Octet C

Octet D

Octet E

87654321

Octet F

Octet G

cch_confPhysical ChannelsCombinedNo of CCHPaging TypeNo of MS using IMSINo of MS using TMSITotal no of MS

01 timeslot (0)NO912-287654321

11 timeslot (0)YES32123Octet 1

22 timeslots (0, 2)NO183-44Octet 2

43 timeslots (0, 2, 4)NO27

64 timeslots (0, 2, 4, 6)NO36

4Decoded

3Not Decoded

2

1

0

SACCH Blocks

COMBINEDCCCH BLOCKSAGCH BLOCKSPCH BLOCKS

No909

No918

No927

No936

No945

No954

No963

No972

Yes303

TX INTEGER RACH SLOTSS FOR NON-COMB CCCHS FOR COMB CCCHYes312

3, 8, 145541max_retransMtx_integerTYes321

4, 9, 1676521103

5, 10, 20109582214

6, 11, 25163863425

7, 12, 3212711547

1518

MCC DIG 1

MCC DIG 2

MCC DIG 3

MNC DIG 1

MNC DIG 2

LAC

LAC

Binary

CI

CI

Binary

Ordered MS Power Level

Spare

Ordered Timing Advance

Spare

t3105

HANDOVER COMMAND

START TIMER T3105

MS

TARGET CELL

SOURCE CELL

HANDOVER ACCESS

PHYSICAL INFORMATION

HANDOVER COMPLETE

IF HO COMPLETE MSGSTOP TIMER T3105

EXPIRED

EXPIRED

HANDOVER ACCESS


IF NO HO COMPLETE MSGAND T3105 EXPIRES SEND PHYSICAL INFO ANDSTART TIMER T3105

NY1 TIMES

HANDOVER FAILURE TO BSC

If NY1 = 0

Sheet6

HANDOVER COMMAND

HANDOVER FAILURE

START TIMER T3103

STOP TIMER T3103

MS

NETWORK

SOURCE CELL

INITIATE HANDOVER

UNSUCCESSFUL HANDOVER

HANDOVER COMPLETE

HANDOVER SUCCESSFUL

TARGET CELL

STOP TIMER T3103

EXPIRED

EXPIRED

Sheet5

POWER CONTROL RXQUAL

Only 2 N above threshold3 N above threshold

So no increase of powerSo Power is increased

by the MS

3 N below thresholdOnly 2 N below threshold

So power is decreased bySo no power is decreased

the BSSthe MS


HANDOVER RXQUAL

-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

l_rxlev_dl_p

u_rxlev_dl_p

-110 dBm

-47 dBm

-85 dBm

-75 dBm

0

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

Increase Power

Decrease Power

Do nothing

-60 dBm

N considered for power increase

N considered for power decrease

-110 dBm

-47 dBm

-90 dBm

-80 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-90 dBm

-80 dBm

-47 dBm

-85 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30

P1 out of N1Increase Power

P2 out of N2Decrease Power

-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

0.14%

0

u_rxqual_ul_pu_rxqual_dl_p

2

3

4

6

7

0.57%

2.26%

9.05%

18.10%

1.13%

l_rxqual_ul_pl_rxqual_dl_p

P4 out of N4 decrease Power


-110 dBm

-100 dBm

-90 dBm

-70 dBm

-47 dBm

0

10

20

30

40

63

0.14%

0


2

4

6

7

0.57%

2.26%

9.05%

18.10%


l_rxqual_ul_hl_rxqual_dl_h

2.26%

Adjust Power

l_rxlev_ul_ihl_rxlev_dl_ih

Quality

Interference

Sheet2

Frame 24Frame 25Idle FrameFrame 0

012345670123456701234567012

012345670123456701234567012


12345

Inteference on idle channel measured on Idle Timeslot by BSS


01234567

01234567

Measurement report sent every 480ms

1st MR2nd MR3rd MR4th MR5th MR6th MR

1

2

3

1

2

1

2

1

2

3

4

5

UPLINK CELL1

UPLINK CELL2

Average

Average

Average

Average

Sheet3

MS

MSC

BSS

HLR

RACH

Imme. Assign

Location update request

Authentication request

Authentication response

DTI

DTI

Cipher mode command

Cipher mode complete

Location update accepted

VLR

T3101

MS

CELL

RACH

CL2I




MS

CELL

RACH


SDCCH ALLOCATED

START TIMER T3101

IF T3101 EXPIRES ANDBSS DOES NOT RECEIVECL2I ON SDCCH RELEASE ALLOCATED RESOURCES

Sheet7






GOS2%2%2%




ERLANGS / km228.1156.2384.34



Sheet1 (2)

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

BCCH

AGCH

25

26

27

28

29

30

31

32

Sheet1

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

Sheet4


10

21

32 and 6

43 and 7


016015014013012011010009

008007006005004003002001

87654321

Octet A

1111Octet BBCD

Octet C

Octet D

Octet E

87654321

Octet F

Octet G


01 timeslot (0)NO912-287654321




64 timeslots (0, 2, 4, 6)NO36

4Decoded

3Not Decoded

2

1

0

SACCH Blocks


No909

No918

No927

No936

No945

No954

No963

No972

Yes303



4, 9, 1676521103

5, 10, 20109582214

6, 11, 25163863425

7, 12, 3212711547

1518

MCC DIG 1

MCC DIG 2

MCC DIG 3

MNC DIG 1

MNC DIG 2

LAC

LAC

Binary

CI

CI

Binary


Spare


Spare

t3105

HANDOVER COMMAND

START TIMER T3105

MS

TARGET CELL

SOURCE CELL

HANDOVER ACCESS


HANDOVER COMPLETE


EXPIRED

EXPIRED

HANDOVER ACCESS



NY1 TIMES


If NY1 = 0

Sheet6

HANDOVER COMMAND

HANDOVER FAILURE

START TIMER T3103

STOP TIMER T3103

MS

NETWORK

SOURCE CELL

INITIATE HANDOVER


HANDOVER COMPLETE

HANDOVER SUCCESSFUL

TARGET CELL

STOP TIMER T3103

EXPIRED

EXPIRED

Sheet5




by the MS



the BSSthe MS


HANDOVER RXQUAL

-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

l_rxlev_dl_p

u_rxlev_dl_p

-110 dBm

-47 dBm

-85 dBm

-75 dBm

0

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-47 dBm

-90 dBm

-80 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-90 dBm

-80 dBm

-47 dBm

-85 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30



-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

0.14%

0


2

3

4

6

7

0.57%

2.26%

9.05%

18.10%

1.13%




-110 dBm

-100 dBm

-90 dBm

-70 dBm

-47 dBm

0

10

20

30

40

63

0.14%

0


2

4

6

7

0.57%

2.26%

9.05%

18.10%



2.26%

Adjust Power


Quality

Interference

Sheet2


012345670123456701234567012

012345670123456701234567012


12345



01234567

01234567



1

2

3

1

2

1

2

1

2

3

4

5

UPLINK CELL1

UPLINK CELL2

Average

Average

Average

Average

Sheet3

MS

MSC

BSS

HLR

RACH

Imme. Assign




DTI

DTI

Cipher mode command



VLR

Wait_indication parameter & Timer T3122The MS requests for resources by sending channel request on RACH.The BSS allocates a SDCCH, if available, and sends a IMMEDIATE ASSIGNMENT message on the downlink. This message contains the details of allocated SDCCH, TSC , TA etc.If no SDCCH is available, the BSS sends a IMMEDIATE ASSIGNMENT REJECT message to the MS.As soon as the MS receives the IMMEDIATE ASSIGNMENT REJECT message, it starts a timer T3122 and setes it equal to wait_parameter_indication.Till the timer T3122 is running, no channel request leaves the MS.The next channel request is sent only after the expiry of T3122. This wait_indication_parameter can be set from 0 to 255 secs.

Wait_indication parameter & Timer T3122

waitindicati

MS

CELL

RACH

IMMEDIATE ASSIGNMENTREJECT (AGCH)

NO SDCCH AVAILABLE

IF T3122 EXPIRES,MS CAN NOW SEND A FRESH REQUEST

SET T3122 IN MS EQUAL TO WAIT_INDICATION

RACH

INACTIVE MODE

T3101

MS

CELL

RACH

CL2I




MS

CELL

RACH


SDCCH ALLOCATED

START TIMER T3101


Sheet7






GOS2%2%2%




ERLANGS / km228.1156.2384.34



Sheet1 (2)

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

BCCH

AGCH

25

26

27

28

29

30

31

32

Sheet1

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

Sheet4


10

21

32 and 6

43 and 7


016015014013012011010009

008007006005004003002001

87654321

Octet A

1111Octet BBCD

Octet C

Octet D

Octet E

87654321

Octet F

Octet G


01 timeslot (0)NO912-287654321




64 timeslots (0, 2, 4, 6)NO36

4Decoded

3Not Decoded

2

1

0

SACCH Blocks


No909

No918

No927

No936

No945

No954

No963

No972

Yes303



4, 9, 1676521103

5, 10, 20109582214

6, 11, 25163863425

7, 12, 3212711547

1518

MCC DIG 1

MCC DIG 2

MCC DIG 3

MNC DIG 1

MNC DIG 2

LAC

LAC

Binary

CI

CI

Binary


Spare


Spare

t3105

HANDOVER COMMAND

START TIMER T3105

MS

TARGET CELL

SOURCE CELL

HANDOVER ACCESS


HANDOVER COMPLETE


EXPIRED

EXPIRED

HANDOVER ACCESS



NY1 TIMES


If NY1 = 0

Sheet6

HANDOVER COMMAND

HANDOVER FAILURE

START TIMER T3103

STOP TIMER T3103

MS

NETWORK

SOURCE CELL

INITIATE HANDOVER


HANDOVER COMPLETE

HANDOVER SUCCESSFUL

TARGET CELL

STOP TIMER T3103

EXPIRED

EXPIRED

Sheet5




by the MS



the BSSthe MS


HANDOVER RXQUAL

-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

l_rxlev_dl_p

u_rxlev_dl_p

-110 dBm

-47 dBm

-85 dBm

-75 dBm

0

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-47 dBm

-90 dBm

-80 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-90 dBm

-80 dBm

-47 dBm

-85 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30



-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

0.14%

0


2

3

4

6

7

0.57%

2.26%

9.05%

18.10%

1.13%




-110 dBm

-100 dBm

-90 dBm

-70 dBm

-47 dBm

0

10

20

30

40

63

0.14%

0


2

4

6

7

0.57%

2.26%

9.05%

18.10%



2.26%

Adjust Power


Quality

Interference

Sheet2


012345670123456701234567012

012345670123456701234567012


12345



01234567

01234567



1

2

3

1

2

1

2

1

2

3

4

5

UPLINK CELL1

UPLINK CELL2

Average

Average

Average

Average

Sheet3

MS

MSC

BSS

HLR

RACH

Imme. Assign




DTI

DTI

Cipher mode command



VLR

CALL QUEINGThe MS requests for resources by sending a request to the BSS on RACH.The BSS assigns a SDCCH and the call setup takes place on the SDCCH.It is possible that after the call setup, their may not be a TCH available for the MS due to congestion..

The Network is able to place this call in a queue along with other MS awaiting assignment of a TCH.The length of the queue can be set in the database.The time for which a MS can stay in the queue can be set by setting the value of T11 timer.

Assig. ReqStart T11Stop T11Queuing IndicationAssign. Compl / FailT11 expires. Clr Req.

TCH RESOURCE REPORTINGThe number of dedicated traffic channel in use within a BSS may be useful information for the MSC.The number of TCH currently allocated can be indicated with a BSSMAP REOURCE INDICATION MESSAGE. The message can be sent to the MSC in different modes.In one-off mode, the MSC asks for a report and the BSS generates one.In the periodic mode, the MSC tells the BSS that it wants reports at regular interval.In spontaneous mode, the report is generated in response to TCH demand.

TCH RESOURCE REPORTING

waitindicati

100% TCH Usage

LWM

HWM

MS

CELL

RACH


NO SDCCH AVAILABLE



RACH

INACTIVE MODE

Traffic Usage

Resource Indication to MSCNo Handover request entertained

Resource Indication to MSCHandover request entertained

No of TCH free

T3101

MS

CELL

RACH

CL2I




MS

CELL

RACH


SDCCH ALLOCATED

START TIMER T3101


Sheet7






GOS2%2%2%




ERLANGS / km228.1156.2384.34



Sheet1 (2)

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

BCCH

AGCH

25

26

27

28

29

30

31

32

Sheet1

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

Sheet4


10

21

32 and 6

43 and 7


016015014013012011010009

008007006005004003002001

87654321

Octet A

1111Octet BBCD

Octet C

Octet D

Octet E

87654321

Octet F

Octet G


01 timeslot (0)NO912-287654321




64 timeslots (0, 2, 4, 6)NO36

4Decoded

3Not Decoded

2

1

0

SACCH Blocks


No909

No918

No927

No936

No945

No954

No963

No972

Yes303



4, 9, 1676521103

5, 10, 20109582214

6, 11, 25163863425

7, 12, 3212711547

1518

MCC DIG 1

MCC DIG 2

MCC DIG 3

MNC DIG 1

MNC DIG 2

LAC

LAC

Binary

CI

CI

Binary


Spare


Spare

t3105

HANDOVER COMMAND

START TIMER T3105

MS

TARGET CELL

SOURCE CELL

HANDOVER ACCESS


HANDOVER COMPLETE


EXPIRED

EXPIRED

HANDOVER ACCESS



NY1 TIMES


If NY1 = 0

Sheet6

HANDOVER COMMAND

HANDOVER FAILURE

START TIMER T3103

STOP TIMER T3103

MS

NETWORK

SOURCE CELL

INITIATE HANDOVER


HANDOVER COMPLETE

HANDOVER SUCCESSFUL

TARGET CELL

STOP TIMER T3103

EXPIRED

EXPIRED

Sheet5




by the MS



the BSSthe MS


HANDOVER RXQUAL

-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

l_rxlev_dl_p

u_rxlev_dl_p

-110 dBm

-47 dBm

-85 dBm

-75 dBm

0

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-47 dBm

-90 dBm

-80 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-90 dBm

-80 dBm

-47 dBm

-85 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30



-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

0.14%

0


2

3

4

6

7

0.57%

2.26%

9.05%

18.10%

1.13%




-110 dBm

-100 dBm

-90 dBm

-70 dBm

-47 dBm

0

10

20

30

40

63

0.14%

0


2

4

6

7

0.57%

2.26%

9.05%

18.10%



2.26%

Adjust Power


Quality

Interference

Sheet2


012345670123456701234567012

012345670123456701234567012


12345



01234567

01234567



1

2

3

1

2

1

2

1

2

3

4

5

UPLINK CELL1

UPLINK CELL2

Average

Average

Average

Average

Sheet3

MS

MSC

BSS

HLR

RACH

Imme. Assign




DTI

DTI

Cipher mode command



VLR

T3109The MS and BSS monitor the appearance of SACCH messages.If an uplink failure occurs and the threshold of lost SACCH messages is reached, the BSS will activate timer T3109.The BSS will stop sending SACCH messages to the MS.The MS will not receive any SACCH messages and hence T100 will expire.When T100 expires the MS will return to ideal mode.The BSS will release the channel resources once T3109 expires.For the downlink failure same pattern is followed except that T100 expires first.T3109 should be set higher than T100 ensuring that the system holds on to the radio link long enough for MS to release it first. Otherwise it will be possible to have two MS on the same TCH.

T3109 LADDER DIAGRAM

Sheet8

MSC

XCDREC

BSC

BTSBTS

T3109

MS

BSS

SACCH

LINK_FAIL EXCEEDEDDEACTIVATE D/L SACCHSTART TIMER T3109

SACCH NOT DECODED

START TIMER T100

SACCH DEACTIVATED ON D/L

T100 EXPIRES. RELEASE RADIO RESOURCES

TIMER T3109 STILL RUNNING

TIMER T3109 EXPIRESBSS RELEASES RADIO RESOURCE

waitindicati

100% TCH Usage

LWM

HWM

MS

CELL

RACH


NO SDCCH AVAILABLE



RACH

INACTIVE MODE

Traffic Usage

Resource Indication to MSCNo Handover request entertained

Resource Indication to MSCHandover request entertained

No of TCH free

T3101

MS

CELL

RACH

CL2I




MS

CELL

RACH


SDCCH ALLOCATED

START TIMER T3101


Sheet7






GOS2%2%2%




ERLANGS / km228.1156.2384.34



Sheet1 (2)

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

BCCH

AGCH

25

26

27

28

29

30

31

32

Sheet1

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

CCCH

BCCH

CCCH

BCCH

CCCH

CCCH

BCCH

CCCH

CCCH

CCCH

SACCH

SACCH

CCCH

CCCH

CCCH

CCCH

SDCCH

SDCCH

SDCCH

SDCCH

BCCH

CCCH

SDCCH

CCCH

SACCH

CCCH

SACCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

CCCH

CCCH

CCCH

SDCCH

BCCH

CCCH

A2

A3

BCCH

CCCH

A0

A1

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A6

A7

BCCH

CCCH

A4

A5

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

A0

BCCH

A4

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

CCCH

CCCH

CCCH

D7

CCCH

CCCH

CCCH

D6

CCCH

CCCH

CCCH

D5

CCCH

CCCH

CCCH

D4

CCCH

CCCH

CCCH

D3

CCCH

CCCH

CCCH

D2

CCCH

CCCH

CCCH

D1

CCCH

CCCH

CCCH

D0

BCCH

CCCH

A2

A3

CCCH

A1

BCCH

CCCH

A6

A7

CCCH

A5

Sheet4


10

21

32 and 6

43 and 7


016015014013012011010009

008007006005004003002001

87654321

Octet A

1111Octet BBCD

Octet C

Octet D

Octet E

87654321

Octet F

Octet G


01 timeslot (0)NO912-287654321




64 timeslots (0, 2, 4, 6)NO36

4Decoded

3Not Decoded

2

1

0

SACCH Blocks


No909

No918

No927

No936

No945

No954

No963

No972

Yes303



4, 9, 1676521103

5, 10, 20109582214

6, 11, 25163863425

7, 12, 3212711547

1518

MCC DIG 1

MCC DIG 2

MCC DIG 3

MNC DIG 1

MNC DIG 2

LAC

LAC

Binary

CI

CI

Binary


Spare


Spare

t3105

HANDOVER COMMAND

START TIMER T3105

MS

TARGET CELL

SOURCE CELL

HANDOVER ACCESS


HANDOVER COMPLETE


EXPIRED

EXPIRED

HANDOVER ACCESS



NY1 TIMES


If NY1 = 0

Sheet6

HANDOVER COMMAND

HANDOVER FAILURE

START TIMER T3103

STOP TIMER T3103

MS

NETWORK

SOURCE CELL

INITIATE HANDOVER


HANDOVER COMPLETE

HANDOVER SUCCESSFUL

TARGET CELL

STOP TIMER T3103

EXPIRED

EXPIRED

Sheet5




by the MS



the BSSthe MS


HANDOVER RXQUAL

-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

l_rxlev_dl_p

u_rxlev_dl_p

-110 dBm

-47 dBm

-85 dBm

-75 dBm

0

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-47 dBm

-90 dBm

-80 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30

Increase Power

Decrease Power

Do nothing

-60 dBm



-110 dBm

-90 dBm

-80 dBm

-47 dBm

-85 dBm

0

63

l_rxlev_ul_p = 20

u_rxlev_ul_p = 30



-110 dBm

-100 dBm

-90 dBm

-80 dBm

-70 dBm

-47 dBm

-85 dBm

-75 dBm

0

10

20

30

40

63

l_rxlev_dl_p = 25

u_rxlev_dl_p = 35

0.14%

0


2

3

4

6

7

0.57%

2.26%

9.05%

18.10%

1.13%




-110 dBm

-100 dBm

-90 dBm

-70 dBm

-47 dBm

0

10

20

30

40

63

0.14%

0


2

4

6

7

0.57%

2.26%

9.05%

18.10%



2.26%

Adjust Power


Quality

Interference

Sheet2


012345670123456701234567012

012345670123456701234567012


12345



01234567

01234567



1

2

3

1

2

1

2

1

2

3

4

5

UPLINK CELL1

UPLINK CELL2

Average

Average

Average

Average

Sheet3

MS

MSC

BSS

HLR

RACH

Imme. Assign




DTI

DTI

Cipher mode command



VLR

T3110 AND T3111 - Normal ReleaseThe system initiates the release of a channel by sending a channel release message to the MS and will start timer TT3109.SACCH messages on the downlink are disconnected.On the receipt of the channel release, the MS starts internal timer T3110 and disconnects the main signalling link.When T3110 times out or when the signalling is disconnect confirmed, the MS deactivates all RF links and returns to BCCH idle mode.When the BSS receives disconnect message, it stops timer T3109 and starts T3111.When T3111 has expired all RF links are terminated.If T3109 times out all RF channels are deactivated and are then free to be allocated.T3109 should be greater than T3110.

T3110 AND T3111 - Normal ReleaseChannel ReleaseStart timer T3109Start timer T3110DisconnectStop timer T3109Start timer T3111UAStop T3110 on thereceipt of UAT3111 expiredRelease Radio Resources

TCH Blocking:When TCH is not allocated to the user after SD allocation ,it is TCH Blocking.It is the failed call attempts which the MS user can notice. It takes place due to lack of TCH Resource.

Reasons for TCH Blocking:Some of them are-High Utilization of TCHTime slot faulty.Lock TRXs.HW Problem.

Solutions for removal of TCH Blocking:Implement half rate or Dual rate.Check FRL & FRU.Add another TRX.If TRX addition not possible, try to share the traffic of that cell with the neighboring cell by changing tilt or orientation.

Useful Report for TCH Blocking:135 TCH Congestion

TCH Assignment:Its a process of by which TCH is assigned to the MS.After the SD request MS gets TCH successfully and the call transfers to TCH it means TCH assignment is successful.For the best KPI TCH assignment should tend to 100%.It degrades due to HW problems.

Reasons for TCH Assignment failure:Hardware Fault(TRXs,Combiner,Duplexer,Cables)VSWRHigh Path Loss.Faulty TMA.High TCH Blocking.Loose connections.DR being used extensively

Solutions for removal of TCH Assignment:Clear VSWRIF TRXs are faulty lock them and try to replace them soon to avoid blockingPath Imbalance clear.Connection from BTS to AntennaConnector connectionCheck TMA.Check Duplexer,Combiner,TRXs connections,Multicuppler etc.Check BOIA card.Check BB2F Card.

Reports for TCH Assignment:

ZEOL to check alarms208 for path imbalance196 for UL-DL interferenceZAHP for Flick report

TCH Drop:Drop during conversation is known as TCH drop. It takes place after connect ACK msg on TCH.TCH drop occurring. For TCH drop first cross check the BCCH of that cell, hardware issue may be, change RXP and RLT value. Find out there is any interference ,neighbor defined.

Reasons for TCH Drop:Wrong Parameter Planning.BAD HOSR.Hardware Fault.High TR Fail.Overshoot.Outage.Due to Low Coverage.Due to ICM Band(CDMA)

Solutions for removal of TCH Drop:Check Parameter:Check the BCCH Plan (C/I or C/A).Co-BSIC & Co BCCH.Check the Timer T 100(should be 20 ms)Check Overshooting:If a cell is picking call from long distance, Check the sample log according to TA..Site Orientation.Effective tilt should be check.Mount position should be check

Cont..Improve HOSR:Check the Hopping plan.

Check the Neighbor PlanHigh TR Fail:Check and clear TR fail from oss end.

Cont..

Bad Coverage:

If the drop call is due to low signal strength uplink, check the receive path of this particular TRX. Check receiver sensitivity, VSWR, feeder connection and etc. Drops due to Low Signal Strength.

If the drop call reason is due to low signal strength downlink, then, check the transmit path. Check cards, feeder and etc.

Use MapInfo or Google Earth to find location of sites.

Effective tilt should be check.

Mount position should be check.

Cont..

Check HW:Check Alarms on site.Check TRXs.Check Slips.Check the Hopping plan.Check BB2F card.Check VSWR, Path imbalance.Connector Connection.Check TMA

Cont..

Drop Reason because of HW Issues:if drops are only on one site, then go for a check for that particular even attach with that site.

If drops are on all sites connected to a single link, then check the slip or interference on that Abis interface.

If Drops are distributed on all site of the BSC, then check the slips on A-ter.

Down Time of the cell.

TRX condition.

BTS should not getting the temperature alarm continuously.

Reports for TCH Drop:166 for TCH DropZEOL for alarms.ZAHP for Flicks.232 for TA report.208 Path Imbalance report.204 for BTS report.216 for all parameter.196 for UL-DL Qul.62 for Adj cell having same or adj freq.

HOSR:Hand over success rate:

If HOSR will be good TCH drop will also be good.

If Handover success rate degrades call drop rate will take place.

Reasons for HOSR:Improper Neighbor planning.CO-BCCH-BSIC issues in Neigh.Parameter Check.HSN clash.SL value.LAC boundary.DAC value mismatch.Syn mismatch.Overshoot.HW Issues.Low Coverage

Solutions for removal of HOSR:Arrange Drive Test:The best way to find the real issues for HO fail make DT and check layer 3 msg gor HO fail.By DT it is very easy to find the fail between cells.Neighbor Tuning:Try to retune neighborsAvoid CO-BCCH-BSIC neighbors.Avoid extra neighs.Delete long distance neighs.Check neighs are defined form both ends.If there are high fail delete and recreate neighs.

Cont..

Parameter Check:Retune SL.It can change bw -90,-95,-105.Check HSN.Check SYN.Retune LDR, LUR, IDR, IUR.Retune LMRG, QMRG, PMRG.DAC value Check:Check DAC value. If DAC value is high or low tune it at the TH value. It should be 2050.

Cont..

Overshoot:When neighs are far away then chances of HO fail increases. In this case ping-pong HI takes place by which fail takes place. So it the inter distance is high its batter to del that kind of neigh. LAC Boundary-Check LAC boundry.High fail takes place there will be Inter BSC cells.High fail takes place there will be Inter MSC cells.Define proper LAC in neigh cells.

Cont..

HW Issues:Clear HW issues.Check TRXs.Check outages.Check BOIA Card. Because if it is faulty incoming and outgoing HO will be fail.Clear Reports:Clear ZEAT.Clear 60.Clear 67.Clear 61.

Reports for HOSR :153 reports for HO fail bw two cells.154 HO analyses.60 for discrepancy.67 for Sync report.61 for one way neigh.ZEAT for CO-BCCH-BSIC neighs74 for HO definition report.ZELO for inter MSC HO report.150 for high HO fail.157 for high HO attempt and call ratio.158 for intra BSS HO observation.62 for Adj cell having same or adj freq.

High RACH Failures:Other reasons look for Random access statistics, if there is a lot of random access failures try to check hardware too. It includes thorough hardware audit including CF Reloading, IDB Setting and reloading, Software synchronization, filter check etc)

Some Important Alarms:BTS Operation Degraded (7604) - It shows VSWR on cell.TRX Operation Degraded (7607)-It shows critical alarm on TRXs.Channel Fail Rate (7745)-It shows faulty TS on TRXs.BCF Operation degradation (7601)-It shows DAC value alarm.Ex-TCH Interference (7744)-TRXs faulty or back plan problem.Mean Holding Time(7743)-to detect faulty channels.Working SD Ratio Below TH level (7712)- .Its for the ratio of SDs.LAPD Fail-TX link fail.Antenna Connection Faulty (7606)-Shows faulty in cable connections.High Temp Alarm-TRXs begins fluctuating.

Mobile Call Setup

Mobile Originated Call:Coach enters the numbers on his phone and pushes send...1 866 567 1234SEND

Mobile Originated Call:The mobile then sends a channel request to the networkThis is done as an up-link request on the RACH.

Mobile Originated Call:The network responds to the mobile with an Immediate AssignmentThis is done as a down-link response on the AGCH.The mobile is given:Channel Type (SDCCH)Timeslot number assignedTraining Sequence Number (TSC)Absolute Radio Frequency Channel Number (AFRCN)Mobile Allocation Number (MAIO)Hopping Sequence Number (HSN)The Reference Request that was sent from the BTSTiming Advance, ( the access delay calculated by the BTS)

Mobile Originated Call:The Mobile then moves to the assigned channel (SDCCH) and then sends a Service Request.This is a request on the SDCCH to tell the network what kind of service the mobile needs.Mobile Originated callSMSData Call

Mobile Originated Call:The Network then sends the Mobile an Authentication Request on the same SDCCHThis is a request for the mobile to process the RAND sent from the AC via the VLR.The RAND is included in this message and the mobile then must process this RAND number and its own Ki number with an A3 algorithm stored on its SIM.This produces a number called SRES. This is the same SRES number that should be in VLR for this subscriber.

Mobile Originated Call:The Mobile then sends a Authentication Response on the same assigned SDCCH timeslot.This will be the SRES number from the mobiles calculation with the RAND number just sent.This SRES number will be sent to the VLR for comparison.If all is well and there is a match at the VLR the subscriber is given access.

Mobile Originated Call:The Network then send the mobile the Ciphering Mode Setting on the same SDCCH timeslot.This sets up the encryption for the phones further transaction on the air interface.

Mobile Originated Call:The mobile responds with a Cipher Mode Complete command on the SDCCH.This tells the network the mobile received the cipher command and is ready.

Mobile Originated Call:The mobile then sends setup message which is the phone numbers to call. (On the SDCCH).This tells the network what number to route the call to.

Mobile Originated Call:The network responds with a Call Proceeding message on the SDCCH timeslot.This lets the phone know that the network got the numbers and is proceeding to route the call.

Mobile Originated Call:If the call is routed and the network gets a connection to the phone then an Assignment Command is send to the phone on the SDCCHThis tells mobile to move to a TCH timeslot and gives the phone its new timeslot allocation.

Mobile Originated Call:The mobile responds with a Assignment Complete Command on the SDCCH.This lets the network know the mobile got its new TCH assignment and is moving to it.

Mobile Originated Call:The Network then sends the mobile an ALERT command letting it know the call is about to be connected. This is a FACCHThis is somewhat like the final warning that the call is about to be connected. This happened on the physical TCH timeslot that was just assigned to the mobile but the network changes the timeslot to a logical FACCH for this alert.

Mobile Originated Call:The Network then sends the connect command to the phone telling it to connect onto the TCH for the call. This also happens on the TCH but again is a logical FACCH.This is the connect message to the phone telling it to go active on the assigned TCH for the call.

Mobile Originated Call:The mobile responds to this message with a Connect Acknowledge response. This is also on the TCH assigned but as a FACCH.This lets the network know the mobile has attached to the TCH timeslot and is ready for the calls connection.

Mobile Originated Call:The Call now takes place and Coach is talking to his dialed party. This is the TCH.

Mobile Terminated Call:45470193402Mrs.Upadhyay picks up here home phone and calls Mr. Dileep Upadhyays mobile number.

Mobile Terminated Call:That call is routed to the GSM networks MSC from the landlines local telco switch.The MSC contacts the VLR for information on where Coachs mobile is located within the network.The VLR tells the MSC where to find Coachs mobile.

Mobile Terminated Call:The VLR then sends a Paging Request to the LAC Coachs mobile was last updated in.This is done as a down-link PCH.Basically the network is looking for Coachs mobile.Coachs mobile should be constantly monitoring the BCH timeslot for PCH, (paging) messages.

The mobile then sends a channel request to the networkThis is done as an up-link request on the RACH.Mobile Terminated Call:

Mobile Terminated Call:The network responds to the mobile with an Immediate AssignmentThis is done as a down-link response on the AGCH.The mobile is given:Channel Type (SDCCH)Timeslot number assignedTraining Sequence Number (TSC)Absolute Radio Frequency Channel Number (AFRCN)Mobile Allocation Number (MAIO)Hopping Sequence Number (HSN)The Reference Request that was sent from the BTSTiming Advance, ( the access delay calculated by the BTS)

Mobile Terminated Call:The Mobile then moves to the assigned channel (SDCCH) and then sends a Paging Response.This is a reply on the SDCCH in response to the paging request earlier. Much like the Service Request the phone is responding to the network as to what services it needs setup to according to the paging request information.

Mobile Terminated Call:The Network then sends the Mobile an Authentication Request on the same SDCCHThis is a request for the mobile to process the RAND sent from the AC via the VLR.The RAND is included in this message and the mobile then must process this RAND number and its own Ki number with an A3 algorithm stored on its SIM.This produces a number called SRES. This is the same SRES number that should be in VLR for this subscriber.

Mobile Terminated Call:The Mobile then sends a Authentication Response on the same assigned SDCCH timeslot.This will be the SRES number from the mobiles calculation with the RAND number just sent.This SRES number will be sent to the VLR for comparison.If all is well and there is a match at the VLR the subscriber is given access.

Mobile Terminated Call:The Network then send the mobile the Ciphering Mode Setting on the same SDCCH timeslot.This sets up the encryption for the Mobiles further transaction on the air interface.

Mobile Terminated Call:The Mobile responds with a Cipher Mode Complete command on the SDCCH.This tells the Network the mobile received the cipher command and is ready.

Mobile Terminated Call:The Network then sends Setup Message to the mobile. (On the SDCCH).This tells the Mobile to being ringing.ringring

Mobile Terminated Call:The Mobile responds with a Call Confirmation message on the SDCCH timeslot.This lets the Network know that the mobile is ready to accept the call.

Mobile Terminated Call:The Network responds with the Assignment Command on the SDCCHThis tells the Mobile to move to a TCH timeslot and gives the phone its new timeslot allocation.

Mobile Terminated Call:The Mobile responds with a Assignment Complete Command on the SDCCH.This lets the Network know the mobile got its new TCH assignment and is moving to it.

Mobile Terminated Call:The Mobile then sends the network the Alert Command on the FACCH (TCH).This is the phones response when Coach pushes the talk button to accept the call.

Mobile Terminated Call:The Mobile then sends the connect command to the Network telling it to connect onto the TCH for the call. This also happens on the TCH but again is a logical FACCH.This is the connect message to the Network telling it to go active on the assigned TCH for the call.

Mobile Terminated Call:The Network responds to this message with a Connect Acknowledge response. This is also on the TCH assigned but as a FACCH.This lets the Mobile know the Network has attached to the TCH timeslot and is ready for the calls connection.

Mobile Terminated Call:The Call now takes place and Coach is talking to his dialed party. This is the TCH.

MobileNetworkMobile Originated...

MobileNetworkMobile Terminated...

RAYLEIGH FADING

This phenomenon is due to multipath propagation of the signal.The Rayleigh fading is applicable to obstructed propagation paths. All the signals are NLOS signals and there is no dominant direct path.Signals from all paths have comparable signal strengths.The instantaneous received power seen by a moving antenna becomes a random variable depending on the location of the antenna.

RICEAN FADING

This phenomenon is due to multipath propagation of the signal.In this case there is a partially scattered field.One dominant signal.Others are weaker.

MOBILE MAXIMUM RANGE

RANGE=

TIMING ADVANCE = DELAY OF BITS (0-63)BIT PERIOD= 577/156.25 = 3.693sec =3.693 * 10e-6 secVELOCITY= 3 * 10e5 Km/secRANGE= 34.9 Km

TIMIMG ADVANCE * BIT PERIOD* VELOCITY2

Physical Channels

GSM-900..124 channelsGSM-1800374 channelsARFCN

ARFCN Calculation

Physical channel

Channelization method

TDMAFDMACDMA

Logical ChannelsTraffic Channels Full rate TCH Half rate TCHSignaling or Control Channels Broadcast Control Channel Common Control Channel Dedicated Control Channel

Traffic ChannelFull rate TCHBit rate=22.8 kbpsVoice bit rate=13 kbpsHalf rate TCHBit rate=11.4 kbpsVoice bit rate=6.5 kbps

Broadcast Control Channels Frequency Correction Channel FCCH To able the Mobile to synchronize to the frequency (Downlink only) Synchronisation Channel SCH Used for sending BSIC (Base station Identity Code) Give TDMA frame number to the Mobile. (Downlink only)

Broadcast Control Channel Cell Global Identity CGI Location Area Identity LAI Channel availability, congestion, MAL

Common Control Channel Paging Channel PCHUsed for paging the mobileReason could be an incoming call or an incoming short message, sends IMSI of Target subscriber & CBCHDownlink only

Random Access Channel RACHUsed for responding to the paging, to originate a callTo acknowledge a page from PCHUplink only

Access Grant ChannelUsed to allocate SDCCH to the mobile(downlink only)AGCH is the final CCCH sent to MS before it moved off the control channel.

Dedicated Control ChannelsStand-alone Dedicated Control ChannelUsed for call setup.Send short messages(SMS) to idle mobile.

Slow Associated Control Channel SACCHCarries information about received signal strength, quality(UL SACCH) & Timing advance & Tx power level (DL SACCH)For sending signal strength & BER measurement of the serving cell and signal strength of BCCHs of neighboring cells

Fast Associated Control Channel FACCHUsed for handover using 2 special stealing bits

NORMAL BURST

DESCRIPTION

SYNCHRONIZATION BURST

FREQ. CORRECTION BURST

ACCESS BURST

T3212 and BTDM and GTDMT3212,BTDM and GTDM are related parameters.T3212 is settable cellwise whereas BTDM & GTDM are settable MSC wise.Suppose T3212 is set as 40 which is 4 hrs.That means after every 4 hrs MS is bound to perfrom periodic registration.BTDM + GTDM should be greater than T3212.If it is not so that is T3212 is greater than (BTDM + GTDM) then after (BTDM + GTDM) expires the MS will be detached by the MSC even before the periodic location update of that MS has taken place,which is undesirable.So T3212 should be exactly synchronised with the (BTDM + GTDM).The timer T3212 is set at the cell level and not in MS.But in the protocol stack of MS there is a layer called Mobility Management(MM) layer.When the MS enters into a cell boundary then it reads the value of T3212 set in that cell from the system information.After that the timer starts ticking in the MS.On expiry of the timer MS will be forced to periodically register itself.In the meanwhile before the timer T3212 expires if the MS moves to a new cell then it will again read the value of T3212 afresh from the system information of this new cell and thus this timer will be reset.Also T3212 should be well synchronised with (BTDM+GTDM) and should be less than (BTDM+GTDM).

CSSR= SDCCH Assignment Success Rate * TCH Assignment Success RateCSSR = Successful Assignments/Call-related Requests x 100%

DFCA - Software Requirements

Functionality required by DFCA

BSS Synchronization provides timeslot-level synchronization between base stations, which is required by DFCA. DFCA needs to have information regarding the TSL, MA list, and MAIO usage in the neighboring cells to estimate interference. This can only be done if all the BTSs are synchronized to the same clock (GPS).

BSC-BSC Interface is recommended when DFCA is implemented over more than one BSC area. Without the interface, DFCA will still work on cells well within the BSC but will have uncontrolled interference at the BSC borders.

THANK YOU - Mitesh Suthar

************************************************************************************************************************

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KPI ANALYSIS_Mitesh.ppt

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