05_RN28195EN20GLA0_BSS Radio Network Operation & Maintenance

8/10/2019 05_RN28195EN20GLA0_BSS Radio Network Operation & Maintenance

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BSS Radio Network Operation & Maintenance

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Soc Classification level

RN28195EN20GLA01 N okia S iemens Networks

BSS Radio NetworkOperation & MaintenanceRG20 (BSS)


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After this module the participants should be able to:

Explain basic BSS protocols and parameters: such as CCS7, SIGTRAN, LAC, CI,RAC and NCC (review)

Describe the differences between Frequency Hopping and Baseband Hoppingtechnique (review)

Apply MML command to interrogate signalling and circuit switched traffic

Interrogate the radio network parameters and RNW objects with MML Commands

Use MML to modify and operate basic radio network parameter

Handling GSM and WCDMA adjacent cells

Objectives


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Speech circuits

BSCCircuit Group Full Rate

GSWB

TCSMETPCM-513

Circuit Group HS4

FR

FR

FR

HS4

TCSMETPCM-512

TCPCM-1

TCPCM-1

TCPCM-3

TCPCM-2

CCSPCM-0

CCSPCM-1

CCSPCM-2

CCSPCM-3

ET-512

ET-513

MGW

Refer to RG20 Documentation:

BSC/TCSM descriptions\ Product description of Flexi BSC\ Functionalityof the Flexi BSC


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CCS7 signalling

BSSAP

SCCP

MTP

MSC

TCSM

BSC

BSSAP

SCCP

MTP


BSC/TCSM descriptions\ Product description of Flexi BSC\ Interfacesrelating to the Flexi BSC

For more detailed information about CCS7 Signalling, see RG20 Documentation:

Administer\ Common Channel Signalling (MTP, SCCP and TC)

MTP: Transmits signalling data to a destination. The MTP consists of at least onesignalling link, a signalling link set, and a signalling route set.

SCCP: Two SCCP services are used in GSM: connectionless service and connection-oriented service. The SSCP uses the MTPs services and offers its own services to theupper layers.

BSSAP: The application part of the base station subsystem. The BSSAP consists ofBSSMAP (BSS Management Part), for messages between BSC and MSC; and DTAP(Direct Transfer Application Part), for messages to and from the mobile station.


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CCS7 signalling - Rel.4

M3UA | MTP

MGW

TCSM

BSC

BSSAP

SCCP

MTP

BSSAP

SCCP

M3UA

MSS

MGW acts as an MTP Signalling Transfer Point between BSC and MSS.


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CCS7 signallingMTP definitions:

-Signalling Link

-Signalling Linkset

-Signalling Routeset


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A-Interface using SIGTRAN protocol stack

M3UA

IP

SCTP

Ethernet

M3UA

BSSAP

IP

SCTP

Ethernet

SCCP SCCP

BSSAP

BSC MSS

SIGTRANSIGTRAN

SIGTRAN defines a standardized way of carrying any SS7 signalling over IPnetworks

For more detailed information about SIGTRAN, see RG20 Documentation:

Administer\ Signalling Transport over IP (M3UA and IUA)


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IP

SCTP

Appli-

cation

L1

L2

Stream Control Transmission Protocol ( SCTP)

Services by SCTP:

provides reliable data transfer between two IPend points

It offers acknowledged error-free non-duplicatedtransfer of datagrams (messages).

Detection of data corruption, loss of data andduplication of data is achieved by usingchecksums and sequence numbers.

A selective retransmission mechanism is applied

to correct loss or corruption of data.


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RN28195EN20GLA010 Nok ia S iemens Net wor ks

SIGTRAN Terms and Concepts

SCTP Associations

IP

MSS (Server)

BSU 1

BSU 0

BSU 2

BSC (Client)

BCSU 1

BCSU 0

BCSU 2

SCTP Association set(up to 16 associations)

An SCTP Association is identified by the computer unit (BCSU) and destination address. Only one associationallowed per computer unit.

A SIGTRAN link" consists of one SCTP Association set.

Signaling Link Set can only contain one "SIGTRAN link".


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SIGTRAN vs TDM SS7


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BCF

Abis-IF structure

TRXSIG BCFSIG TCHGSWET

OMU BCSU

D-BUS

BTS1+1+1BSC

BCF

Abis Structure

Abis Interfacecompressed allocation

123456789

1011121314151617

18192021222324252627282930

0

1 2 3 4 5 6 7 8

31

fixedCCITT framedataTCH 1 TCH 2 TCH 3

TCH 5 TCH 6 TCH 7

TCH 1 TCH 2 TCH 3

TCH 5 TCH 6 TCH 7

TCH 4

TCH 4

TCH 1 TCH 2 TCH 3

TCH 5 TCH 6 TCH 7TCH 4

TRXSIG 1

TRXSIG 3

TRXSIG 5

BCFSIG

1 2 3 4 5 6 7 8

1234

0 fixedCCITT framedataBCFSIG T CH 2 T CH 3


TCH 1 TCH 2 TCH 3


TRXSIG 2

TRXSIG 1

TRU

TRX-1

TRX-3

TRX-5

ET

ET

MCMU

For more detailed information about D-channels, see RG20 Documentation:Administer\ D-channel Services

Abis interface

Each BTS has one O&M channel, BCFSIG (or OMUSIG):

it is an LAPD link connected to the BCF unit in the BTS

the bit rate is 16, 32 or 64 kbit/s

One TRX can handle 8 x 16 kbit/s traffic channels, TCHs:

it needs two PCM timeslots for TCHs in Abis

one TRX has one LAPD link, TRXSIG with 16, 32 or 64 kbit/s bitrate


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Location area and cell ID

CI= 1

CI= 2

CI= 3

CI= 1

CI= 2

CI= 1

CI= 2

CI= 3

BSC 1

BSC 2

BSC 3

VLR1

LAC: 300LAC: 200

LAC: 100

BTS Parameters

Mobile Country Code and Mobile Network CodeThe mobile country code (MCC) defines the code of each country globallywhile the mobile network code (MNC) defines the unique network codewithin a country.

Location Area CodeThe MSC service area has been divided into several smaller areas, whichare called location areas (LAC). Each location area has a unique number -a location area code- to identify the area. Paging a mobile in case of anincoming call is based on the location area.

Cell IdentityA location area may include several BSCs, BCFs and BTSs. Therefore, aunique Cell identity (CI) is needed to define each individual cell within alocation area. The range of CI numbers is 0-65535. In MML each cell isrepresented by a Segment consisting one or more BTS objects.

The Cell Global Identification CGI=MCC+MNC+LAC+CI has to be definedin MCS and BSC.


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Routing area

LAC=10CI=1001

LAC=10CI=1003

LAC=10CI=1002

LAC=10CI=1004

LAC=10CI=1005

LAC=10CI=1010

LAC=10CI=1009

LAC=20CI=1001

LAC=20CI=1003

LAC=20CI=1002

LAC=20CI=1005

LAC=20CI=1007

LAC=20CI=1008

LAC=10

CI=1008

LAC=20CI=1004

LAC=20

CI=1006

LAC=10

CI=1006

LAC=10CI=1007

RAC=1

RAC=2 RAC=3

RAC=1

RAC=2

RAC=3

Routing Area

From the GPRS point of view Location Area (LA) and Cell information is not enough. A

new logical element in an Air interface is called a Routing Area (RA). A Routing Areahelps to optimise the load caused by GPRS mobility management.One or more cells form a Routing Area, which is a subset of one Location Area; all thecells must be entirely contained within the same LA. The Routing Area is unique within aLocation Area. Handling mobility management in the GPRS network is similar to handlingmobility management in the existing GSM system. As Routing Areas are served bySGSNs, it is important to remember the network configuration plan and what has beendefined in the SGSN when configuring the BSC side. The information has to be the samein the SGSN and the BSC.

A Routing Area is contained within an SGSN, and all BTSs for the same RA have to beconnected to the same SGSN. RAs are not confined to a particular PCU. Several PCUscan serve one RA and one PCU can handle several RAs.When creating a Routing Area, the user identifies the obligatory parameters Mobile

Country Code (MCC), Mobile Network Code (MNC), Location Area Code (LAC) andRouting Area Code (RAC).The MCC, MNC, LAC and RAC parameters constitute a Routing Area Identification(RAI). In other words: The Routing Area and the BTSs are linked logically together by theRAI. Routing Areas are used in the PCU selection algorithm, which selects a servingPCU for a cell when the operator enables the GPRS traffic in that cell.

RAI = MCC+MNC+LAC+RAC

Optimal Routing Area size

If the Routing Area size is too large, the paging channels and capacity will be saturateddue to limited LAPD Abis or radio interface CCCH paging capacity.

With a small Routing Area there will be a larger number of Routing Area updates.


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Network Colour Code

GreenNation

Brown Land

Country GSMfreq.=1BCC=0NCC=0

f 1 f 1

1st Nation GSMfreq.=1BCC=0NCC=3

Network colour code (NCC)

Network colour code is used in arbitrary situations on country borders in order todefine the network from which a mobile gets its service. In every country thewhole GSM frequency band has been allocated among local operators. In thevicinity of country borders it is possible for the mobile to receive the samefrequency from both countries. Therefore, NCC is used to define which network aparticular frequency belongs to. The range of NCC is between 0-7. NCC is basedon the common agreement between neighbouring operators.


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Base Station Colour Code

BCC=1

BCC=2

BCC=0

f1

f2

f4

f3

f5f1

f2

f5

f4

f3

f5

f4

f1

f3

f2

Base station colour code (BCC) and base station identity code (BSIC)

Within a national network there is a similar problem, but from a different source. Due tothe limited number of carriers, frequencies need to be reused rather often. This results inan arbitrary situation for mobiles that receive the same frequency from several sources.Using base station colour code solves the problem; the BCC describes a group of BTSsusing a set of frequencies. Another BCC is given to the neighbouring frequency set. Therange of BCC is between 0-7.

NCC and BCC together comprise a code called Base Station Identity Code (BSIC). BSICis transmitted to mobiles on Synchronisation Channel. The mobile decodes thisinformation, and is therefore able to lock onto the correct network and BTS (=cell).

BSIC = NCC + BCC


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Modifying a radio network parameter

Lock Network Object (BTS, TRX)

Modify Parameter

Unlock Network Object (BTS, TRX)

Modify involved NE (eg. MSS,BTS)Influence

on involved NetworkElements

End

Start

Yes

No


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Logical Channel Types

LOGICAL

CHANNELS

COMMONCHANNELS

DEDICATEDCHANNELS

TRAFFIC

CHANNELS

DEDICATED

CONTROL

CHANNELS

COMMONCONTROL

CHANNELS

BROADCASTCHANNELS

FCCH SCH BCCH CBCH PCH RACH AGCH SDCCH SACCH FACCH TCH Data


Functional area descriptions\ Radio network performance\ RadioChannel Allocation\ Overview of radio channel allocation

Functional area descriptions\ Radio network performance\ Basic Call\Procedures in Basic Call

A logical channel defines the type of information sent in a burst.

Logical channels are mapped onto physical channels.

One physical channel can carry more than one logical channel.

Abbreviations:

FCCH: Frequency Correction Channel

SCH: Synchronization Channel

BCCH: Broadcast Control Channel

CBCH: Cell Broadcast Channel

PCH: Paging Channel

RACH: Random Access Channel

AGCH: Access Grant Channel

SDCCH: Stand Alone Dedicated Control Channel

SACCH: Slow Associated Control Channel

FACCH: Fast Associated Control Channel

TCH: Traffic Channel (FR, EFR, HR)

Data: Data Channel (14.4KBit/S, 9,6kBit/S)


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Exercise: Interrogation of the radio network

BSC

BTS=CI=LAC=f1=f2=

BTS=CI=

LAC=f1=f2=

BTS=CI=

LAC=f1=f2=

BCF=..

BTS=CI=LAC=f1=f2=

BTS=CI=

LAC=f1=f2=

BTS=

CI=LAC=f1=f2=

BCF=..

BTS=CI=LAC=f1=f2=

BTS=CI=LAC=f1=f2=

BTS=CI=LAC=f1=f2=

BCF=..

ET

ET

ET

ET

ET

ET

ET

ET

Exercise: Interrogation of the radio network. Duration: 40 min.

Requirements: 1 MML terminal per workgroup.

Write down the used MML commands!

Interrogate the radio network of your classroom BSS!

__________________________________

__________________________________

Make a drawing of the network according to the

picture above and fill in the missing parameters.

Interrogate the Abis structure of ET. and fill in

TCHs TRXSIGs and BCFSIGs in the frame beneath.

__________________________________

__________________________________

Choose one BTS for interrogating the TRX configuration.__________________________________

TRX1 TRX2CH0: _____ ______CH1: _____ ______CH2: _____ ______CH3: _____ ______CH4: _____ ______

CH5: _____ ______CH6: _____ ______CH7: _____ ______

fixed CCITTframe data

1 2 4 5 6 7 83

0

1

2

3

4

5

6

7

8

9

10

11

12

13

1415

16

17

18

20

22

26

29

31

19

21

23

24

25

27

28

30


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You are working on BTS number:

Modify the CI of your BTS (Choose a number that is not used so far).

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

What is the effect on other network elements?

___________________________________________________________________________

Change the frequency (ARFN) of your BCCH TRX (Choose a number that is not used so far).

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

Interrogate the Routing Area Code of your BTS.

___________________________________________________________________________


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Radio Link Measurements

BSC

BSC

DL

UL

Serving cell

Adjacent cells

BTS Reporting inevery 480 ms

(960 ms)

DL: Rx LevelRx Quality

Adjacent cell Rx Levels

UL: Rx LevelRx Quality

MS-BTS Distance


Functional Area Descriptions\Radio Network performance\ RF PowerControl and Handover Algorithm\ Overview to RF Power Control andHandover Algorithm

Measurements are sent via SACCH every 480 ms.

Measurements are transferred via TRXSIG on Abis interface. The algorithms to handlethe different types of measurements are located in the BCSU.

The BCSU provides the results.

The MCMU is responsible for further processing and decision-making concerning BSSresource management.


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Power control in DX 200 BSC

Power control for MS and BTS (non-BCCH)Averaging and threshold comparison as in

handover cases

Causes for POC: high/low signal quality (ul/dl)

high/low signal level (ul/dl)

New power level determination by HOC&POCalgorithm

BTS MS Power Control

BS Power Control

MS TX Power Level


Descriptions\ Functional Area Descriptions\ Radio NetworkPerformance\ RF Power Control and Handover Algorithm\ Overview ofRF Power Control and Handover Algorithm

Power control is done for:

MS

BTS

no power control for TRX carrying BCCH

BTS MS Power Control

BS Power Control

MS TX Power Level

BTS BTS Measurements

MS Measurements

MS Measurements

SACCH

SACCH

TRXSIG

TRXSIG


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Frequency hopping

RTSL 0 1 2 3 4 5 6 7

TRX-1 f1

TRX-2 f2

TRX-3 f3

TRX-4 f4

Synthesized Hopping:

Base Band Hopping:

TRX-1

TRX-2

f1,f2,f3,f4,

f1,f2,f3,f4,

.....

B

B

B = BCCH timeslot. It does nothop.

Time slots 1...7 of all TRXshop over MA(f1, f2, f3, f4).This hopping group usesHSN-2.

MAIOs have to be differentbetween

same RTSLs in same hoppinggroup.

0 0 0 0 0 00

1 1 1 1 1 11

2 2 2 2 2 22

3 3 3 3 3 33

0

1

2

Time slot 0 of TRX-2,-3,-4 hop over MA (f2, f3, f4).This hopping group uses HSN-1.

B = BCCH timeslot. TRX does not hop.

Non - BCCH TRXs are hopping overthe MA -list (f1,f2,f3,...,fn) attached to the cell.

fa

(fb)

(fc)

MAIOs have to be different betweensame RTSLs in same hopping group.

Only one hopping group. Only HSN-1 ismeaningful.

TRX-3

0 0 0 0 0 0 00

1 1 1 1 1 1 11

Baseband hopping management

There are two different hopping groups used with baseband hopping in each BTS. When theIntelligent Frequency Hopping (IFH) feature is used, an additional hopping group 3 is in use.

Group 1All radio time slots, except the BCCH time slot (RTSL-0), on the BTS belong to Group 1. It ismanaged through FHS-1 in the BSC's database. HSN1(hopping sequence number 1) is related tothis group.

Group 2All radio time slots (RTSL-1 to 7) on the BTS belong to Group 2. It is managed through FHS-2 inthe BSC's database. HSN2 is related to this group.

If baseband hopping is used on the BTS, all radio time slots belonging to the BTS are defined ashopping. The only exception to this is the BCCH time slot, which is always defined as non-hopping.In case there are dedicated signalling channels (SDCCH, CBCH) on the BCCH time slot, they donot hop either.

These hopping groups are maintained by adding and removing the Absolute Radio FrequencyChannel Numbers (ARFCN) of the TRXs used in frequency hopping in the BTS. Based on theavailable ARFCNs in the BTS, the following hopping parameters, stored in the BSS Radio NetworkConfiguration Database (BSDATA), are updated:

- Mobile Allocation (MA)

- Mobile Allocation Index Offset (MAIO)If baseband hopping is used in the BTS, you have to give a hopping sequence number (HSN) forall the hopping groups in the BTS.

RF hopping management

RF hopping can be used when the transceivers of the BTS are of the hopping synthesiser type(Nokia Talk family of base stations or Nokia PrimeSite). Then you can choose the frequencyhopping mode between non-hopping, RF hopping, and BB hopping. When the transceivers of theBTS are of the conventional type (Nokia 2nd generation base stations), only non-hopping or BBhopping are possible.

The frequencies for a hopping cell are defined by attaching the cell to one of the mobile allocationfrequency lists (MA-lists) defined by the operator. The system calculates the MAIOs, and theoperator gives the HSN for the cell. The BCCH transceiver cannot hop, but it transmits acontinuous BCCH frequency. Note that the MA used must contain at least as many frequencies asthere are unlocked hopping transceivers in the BTS. The MA or the HSN can be changed only

when the hopping cell is locked.You can create up to 255 mobile allocation frequency lists (MA-lists) and use them freely withdifferent cells. One list can contain up to 63 frequencies.


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Exercise: Cell parameter interrogation

BSC BTS/SEG

POC

HOC

CH

Exercise: Cell Parameter Interrogation, duration:~20min

Required equipment: working VDU terminal for each work group.

You are interrogating BTS /SEG

Power Control (POC)

Interrogate parameters concerning Power Control (ZE.)

MML command:_______________________________________________________

How could you modify those parameters?

MML command:_______________________________________________________

Handover Control (HOC)

Interrogate parameters concerning Handover Control (ZE.)

MML command:_______________________________________________________


MML command:_______________________________________________________

Frequency Hopping System (FHS)

Interrogate parameters concerning Hopping System (ZEQ.)

MML command:_______________________________________________________


MML command:_______________________________________________________

Radio Timeslots (CH)

Interrogate parameters concerning Radio Timeslots (ZER.)

MML command:_______________________________________________________


MML command:_______________________________________________________


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Adjacent cells

BSC 2

RNC 1

BTS = 4Name = Dormagen

LAC = 501

CI = 1004BCCH freq = 710

BTS = 1Name = Bonn1

LAC = 504


BTS = 1

Name = Kln 1

LAC = 500


BTS = 3

Name = Kln 3LAC = 500

CI = 10003

BCCH freq = 870

SEG = 2

Name = Kln 2

LAC = 500


LAC = 504CI = 10040

SCC = 44

Freq = 1234

BSC

BCC=0

NCC=0

A segment can consists of several BTSs. They are necessary for combining differentFrequency bands or different BS hardware into one logical cell. Segments arerepresented by one Cell Identity.

Commands of Adjacent cell handling in BSC

ZEA?

C: ..... CREATE ADJACENT CELL PARAMETERS

D: ..... DELETE ADJACENT CELL PARAMETERS

R: ..... DELETE INCOMING ADJACENT CELLS

M: ..... MODIFY ADJACENT CELL PARAMETERS

X: ..... MODIFY C/I HANDOVER PARAMETERS

O: ..... OUTPUT ADJACENT CELL PARAMETERS

P: ..... OUTPUT SHORT LIST OF ADJACENT CELL PARAMETERS

T; ..... CHECK ADJACENT CELL DATA

Adjacent cells in same BSC area are given by BTS number and foreign Adjacent cellsare defined with necessary cell parameters.


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Exercise: Adjacent cells

BSC y

RNC x

BTS = ..

Name =

LAC = ..

CI = ..BCCH freq =

LAC =.CI =.

SCC =

Freq = .

BSC

BCC=NCC=

BTS = ..Name =

LAC = ..

CI = ..

BCCH freq =

BTS = ..

Name = LAC = ..

CI = ..BCCH freq =

BTS = ..Name =

LAC = ..

CI = ..BCCH freq =

BTS = ..

Name = LAC = ..

CI = ..

BCCH freq =

Exercise: Adjacent cells. Duration 20 min

Requirements: for each group 1 working BTS and a MML terminal

You are working on BTS No______!

Find out the missing parameters of your BTS and update the drawing above.

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

Check all existing adjacencies to your BTS and delete them.

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________Choose 2 cells of your BSS and create one directional adjacencies. Present theadjacencies with arrows in the picture above.

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

Create an adjacency to a cell of another BSS.

____________________________________________________________________

____________________________________________________________________

Create an adjacency to a cell of a WCDMA cell.

____________________________________________________________________

Documents

05_RN28195EN20GLA0_BSS Radio Network Operation & Maintenance