dap

Dynamic Abis Pool Handling

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# Nokia Siemens Networks 1 (22)

BSC3153Nokia GSM/EDGE BSS, Rel. BSS13, BSC andTCSM, Rel. S13, Product Documentation, v.1

The information in this document is subject to change without notice and describes only theproduct defined in the introduction of this documentation. This documentation is intended for theuse of Nokia Siemens Networks customers only for the purposes of the agreement under whichthe document is submitted, and no part of it may be used, reproduced, modified or transmitted inany form or means without the prior written permission of Nokia Siemens Networks. Thedocumentation has been prepared to be used by professional and properly trained personnel,and the customer assumes full responsibility when using it. Nokia Siemens Networks welcomescustomer comments as part of the process of continuous development and improvement of thedocumentation.

The information or statements given in this documentation concerning the suitability, capacity, orperformance of the mentioned hardware or software products are given “as is” and all liabilityarising in connection with such hardware or software products shall be defined conclusively andfinally in a separate agreement between Nokia Siemens Networks and the customer. However,Nokia Siemens Networks has made all reasonable efforts to ensure that the instructionscontained in the document are adequate and free of material errors and omissions. NokiaSiemens Networks will, if deemed necessary by Nokia Siemens Networks, explain issues whichmay not be covered by the document.

Nokia Siemens Networks will correct errors in this documentation as soon as possible. IN NOEVENT WILL NOKIA SIEMENS NETWORKS BE LIABLE FOR ERRORS IN THISDOCUMENTATION OR FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO SPECIAL,DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL OR ANY LOSSES, SUCH AS BUTNOT LIMITED TO LOSS OF PROFIT, REVENUE, BUSINESS INTERRUPTION, BUSINESSOPPORTUNITY OR DATA, THAT MAYARISE FROM THE USE OF THIS DOCUMENT OR THEINFORMATION IN IT.

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Copyright © Nokia Siemens Networks 2008. All rights reserved.

2 (22) # Nokia Siemens Networks DN01444Issue 5-0 en19/02/2008


Contents

Contents 3

List of tables 4

List of figures 5

Summary of changes 7

1 Creating a dynamic Abis pool 11

2 Modifying a dynamic Abis pool 17

3 Deleting a dynamic Abis pool 21

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Contents

List of tables



List of figures

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List of figures

Summary of changes

Changes between document issues are cumulative. Therefore, the latestdocument issue contains all changes made to previous issues.

Changes made between issues 5-0 and 4-0

Creating a dynamic Abis pool:

. The note on ETSI and ANSI environments has been converted toplain text.

. Reference to PBCCH/PCCCH has been removed.

. Information on the EDGE-capable TRXs in the BTSs has beenupdated in section Radio network limitations.

. The warning has been converted to a caution.

. The note on creating a new DAP in a PCU has been converted toplain text and moved to section Before you start.

. Information on Packet Control Unit (PCU2) Pooling has been addedto section Before you start.

. The heading of step Check that you have free Abis interface PCMcapacity (WUP) has been changed to Check to which ET-PCM theAbis interface has been connected (WUP). Information in that stephas been updated.

. Step Check that the ET-PCM has space for a dynamic pool (WUP)has been added.

. New command and information on Packet Control Unit (PCU2)Pooling have been added to step Create the dynamic Abis pool(ESE).

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Summary of changes

. Example Creating a dynamic Abis pool (Packet Control Unit (PCU2)Pooling not in use) has been updated.

. References to EGPRS, Extended Cell for GPRS/EDGE, CodingSchemes CS-3 and CS-4, and Packet Control Unit (PCU2) Poolingactivation instructions have been added.

Modifying a dynamic Abis pool:


. The note on modifying an existing DAP of a PCU has beenconverted to plain text.

. Information on Packet Control Unit (PCU2) Pooling has been added.

. The commands and examples have been updated in steps Modify adynamic Abis pool by adding timeslots to the beginning or end of thepool (ESM) and Modify a dynamic Abis pool by removing timeslotsfrom the beginning or end of the pool (ESM).

. New step Modify a dynamic Abis pool by changing the PSE (ESM)has been added. An example has also been added.

. Information on the segments that are attached to DAP has beenadded to steps Modify a dynamic Abis pool by changing the BCSUand the PCU (ESM) and Modify a dynamic Abis pool by changingPSE (ESM).

. References to EGPRS and Packet Control Unit (PCU2) Poolingactivation instructions have been added.

Deleting a dynamic Abis pool:


. The note on deleting an existing DAP of a PCU has been convertedto plain text and moved to section Before you start.

Changes made between issues 4-1 and 4-0

Creating a dynamic Abis pool:

The theoretical maximum number of dynamic Abis pools in a BSC hasbeen changed from 470 to 1600.



Changes made between issues 4-0 and 3–2

Some of the limitations listed at the start of Chapter 1 have been moved tothe description of Dynamic Abis.

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Summary of changes

1 Creating a dynamic Abis pool

These instructions apply to both ETSI and ANSI environments.

Space is reserved from the Packet Control Unit Pulse Code Modulation(PCUPCM) serial line in the order of creation. The pools are rearrangedoptimally to the PCUPCM during Base Station Controller Signalling Unit(BCSU) restart, Marker and Cellular Management Unit (MCMU) restart, orBCSU switchover.

You should not reserve Abis resources for pools that will not be used, as itwill prevent the resources from being allocated for other traffic.

PCU limitations:

. There can be 16 dynamic Abis pools in one logical PCU.

. In one logical PCU there can only be 256 Abis channels (includingDefault GPRS + EGPRS dynamic Abis pool (EDAP) channels).

Note that the number of default GPRS channels includes EGPRSchannels.

. You cannot configure more than 204 EDAP channels in one logicalPCU. This is because there must also be space for at least 1EGPRS channel for every 4 EDAP channels (51 EGPRS channels +204 EDAP channels = 255 Abis channels).

The rationale for this is that a single EGPRS radio timeslot uses amaximum of 4 16kbit/s EDAP channels.

Radio network limitations:

. The theoretical maximum number of dynamic Abis pools in a BSC is1600. However, the practical maximum is determined by the numberof PCUs in the BSC.

. The maximum size for a single EGPRS dynamic Abis pool (EDAP)area is 12 x 64 kbit/s PCM timeslots (48 EDAP channels per DAP).

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Creating a dynamic Abis pool

. The theoretical maximum number of transceivers (TRXs) attached toone dynamic Abis pool is 20. However, since TRXs using DAPresources must be allocated to the same Abis external PCM circuit(ET-PCM) line with EDAP, the maximum number of TRXs per DAP isless than 20.

. The serving PCU must be the same for all TRXs under one segment(also including possible dynamic Abis pools attached).

. Dynamic Abis pool + TRX signalling link + traffic channels (TCHs)must be located on the same ET-PCM.

. The DAP attached to the TRX, and the network service entityidentifier (NSEI) serving the BTS of the TRX, have to be in the samePCU.

. If EGPRS or Coding Schemes CS-3 and CS-4 is enabled in a BTS,the BTS must have EDGE-capable TRXs that are connected to aDAP. The non-EDGE TRXs of that BTS must be GPRS disabled. Ifthere are EDGE TRXs and non-EDGE TRXs in the BTS, see morespecific instructions in Activating and Testing BSS10083: EGPRSand Activating and Testing BSS11088: Coding Schemes CS-3 andCS-4 under Test and activate/Data in the PDF view.

. If Extended Cell for GPRS/EDGE is enabled in the cell, all the TRXsin the BTSs using GPRS/EDGE in the segment must be EDGE-capable and must be attached to the DAP.

. The non-EDGE TRXs cannot be attached to a DAP.

Caution

Sharing the EGPRS dynamic Abis pool (EDAP) between severalcabinets may damage the transceiver or transmission unit (TRU)hardware. One EDAP resource should not be shared between severalbase control function (BCF) cabinets.

Note

Only EDGE-capable transceivers are able to use dynamic Abis pool(DAP) resources.

For more information, see



. Packet Control Unit (PCU) in GPRS/EDGE System FeatureDescription under Feature descriptions/Data in the PDF view.

. Dynamic Abis Pool management in Dynamic Abis under Featuredescriptions/Data in the PDF view.

Before you start

When creating a new dynamic Abis pool, the BSC turns off the GPRStraffic from the logical PCU to which the new DAP is to be created. TheBSC downgrades all packet switched traffic channels from the PCU andupgrades these traffic channels to packet switched use again. This shortinterruption ensures that the BSC can find a block of free timeslots fromthe PCUPCM. Creating a new DAP in a PCU causes a reallocation ofdigital signal processor (DSP) resources in the PCU between the new andexisting DAPs and GPRS channels. It also ensures the optimised PCUDSP resource usage for each DAP connected to a specific PCU. If PacketControl Unit (PCU2) Pooling is in use and the DAP is created for a packetservice entity (PSE), this kind of interruption in the GPRS traffic takesplace in the PCU where the PCU selection algorithm attaches the DAP.

Note

You must configure dynamic Abis pools of the same size and the sametimeslots in both the BSC and the base transceiver station (BTS).

Steps

1. Check whether you have a suitable dynamic Abis pool created(ESI).

ZESI;

If not, move on to the next step.

2. Check that you have a PCU card configured to a certain BCSU(WTI).

You cannot create a dynamic Abis pool if there is no logical PCUconfigured to a BCSU.

In BSC3i, a physical PCU plug-in unit is created with two separateelements (two plug-in units with their own PIU/plug-in unit indexes inMML) which can be considered as two logical PCUs.

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ZWTI:<information type>:<unit identification>:<plug-in unit identification>;

Now you can check from the output list if a logical PCU is configuredto BCSU-0.

If yes, move on to the next step.

3. Check to which ET-PCM the Abis interface has been connected(WUP).

ZWUP;

In the list you find several ET-PCMs configured on your system.Select a suitable ET-PCM where to create the dynamic Abis pool.

4. Check that the ET-PCM has space for a dynamic pool (WUP).

ZWUP:<pcm circuit number>::CGR;

You can see free timeslots in the list.

5. Create the dynamic Abis pool (ESE).

ZESE:<pool id>,<circuit>,<size>,<BCSU id>,<PCU id>;

or

ZESE:<pool id>,<circuit>,<size>,<PSEI>;

Use the second command if Packet Control Unit (PCU2) Pooling isused. Note that Packet Control Unit (PCU2) Pooling is a licence-based application software product and requires a valid licence inthe BSC. For more information, see Licensing in BSC under Installand upgrade/Software in the PDF view.

Example Creating a dynamic Abis pool (Packet Control Unit (PCU2)Pooling not in use)

Create a dynamic Abis pool whose pool id is 1, circuit is ET-PCM number32, pool size is 6 timeslots starting at the fifth timeslot, BCSU index is 0and PCU plug-in unit index is 2:

ZESI;

ZWTI:P:BCSU,0;



ZWUP;

ZWUP:32::CGR;

ZESE:ID=1,CRCT=32–5,SIZE=6,BCSU=0,PCU=2;

Further information

. Alarm 3068 EGPRS DYNAMIC ABIS POOL FAILURE is raised if thedynamic Abis pool creation fails for some reason. For moreinformation on the possible causes of the failure and recoveryinstructions, see Failure Printouts (2000-3999) under Reference/Alarms in the PDF view.

. For instructions on attaching a dynamic Abis pool to a TRX, seeActivating and Testing BSS9006: GPRS under Test and activate/Data in the PDF view.

. Activating and Testing BSS10083: EGPRS under Test and activate/Data in the PDF view

. Activating and Testing BSS20094: Extended Cell for GPRS/EDGEunder Test and activate/Data in the PDF view

. Activating and Testing BSS11088: Coding Schemes CS-3 and CS-4under Test and activate/Data in the PDF view

. Activating and Testing BSS20106: Packet Control Unit (PCU2)Pooling under Test and activate/Data in the PDF view

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2 Modifying a dynamic Abis pool


You can modify the dynamic Abis pool (DAP) size or change thecontrolling logical packet control unit (PCU) or the packet service entity(PSE) to optimise the use of the pools and shared resources.

You can change the controlling logical PCU of the DAP if you want tobalance the traffic load between PCUs. When Packet Control Unit (PCU2)Pooling is in use, you can balance the traffic load between the PCUs bymoving the DAP to a new PSE or with the reallocation command FXF.

With the dynamic Abis measurement you can measure the peak andaverage usage of the dynamic Abis pool and MCS limitations andrestrictions for TBF scheduling. For more information, see 76 DynamicAbis Measurement under Reference/Counters/performance indicators/GPRS measurements (PS) in the PDF view.

Before you start

When modifying the dynamic Abis pool, the BSC turns off the GPRS trafficfrom the logical PCU where the modified pool exists. The BSCdowngrades all packet switched traffic channels from the PCU andupgrades these traffic channels to packet switched use again. This shortinterruption ensures that the BSC can find a block of free timeslots fromthe Packet Control Unit Pulse Code Modulation (PCUPCM) serial line.Modifying an existing DAP of a PCU causes a reallocation of digital signalprocessor (DSP) resources in the PCU between the new and existingDAPs and GPRS channels. It also ensures optimised PCU DSP resourceusage for each DAP connected to a specific PCU. If Packet Control Unit(PCU2) Pooling is in use and the DAP is moved to a new PSE, this kind ofinterruption in the GPRS traffic takes place in the source PCU and also inthe target PCU where the PCU selection algorithm attaches the DAP in thenew PSE.

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Modifying a dynamic Abis pool

Note

You must configure dynamic Abis pools of the same size and the sametimeslots in both the BSC and the base transceiver station (BTS).

Steps

1. To implement this step, choose one of the followingalternatives:

a. Modify a dynamic Abis pool by adding timeslots to thebeginning or end of the pool (ESM).

When adding new timeslots to the beginning or end of thedynamic Abis pool, ensure that there is enough space in thepool.

ZESM:<pool id>,<new first timeslot|new lasttimeslot>;

Example Modifying the dynamic Abis pool

Modify the dynamic Abis pool whose id is 1 and pool starting from thetimeslot 3 so that you add two timeslots to the beginning of the pool:

ZESM:ID=1,NFT=3;


Modify the dynamic Abis pool whose id is 1 and pool ending to the timeslot15 so that you add five timeslots to the end of the pool:

ZESM:ID=1,NLT=15;

b. Modify a dynamic Abis pool by removing timeslots fromthe beginning or end of the pool (ESM).

ZESM:<pool id>,<new first timeslot|new lasttimeslot>;


Modify the dynamic Abis pool whose id is 1 and pool starting from thetimeslot 6 so that you remove three timeslots from the beginning of thepool:



ZESM:ID=1,NFT=6;


Modify the dynamic Abis pool whose id is 1 and pool ending to the timeslot11 so that you remove four timeslots from the end of the pool:

ZESM:ID=1,NLT=11;

c. Modify a dynamic Abis pool by changing the BCSU andthe PCU (ESM).

All the segments that are attached to the dynamic Abis poolwill be moved to the new PCU.

ZESM:<pool id>,<BCSU id>,<PCU id>;

Example

Modify the dynamic Abis pool whose id is 1 so that you change the BaseStation Control Signalling Unit (BCSU) and the logical PCU:

ZESM:ID=1,BCSU=1,PCU=4;

d. Modify a dynamic Abis pool by changing the PSE (ESM).

All the segments that are attached to the dynamic Abis poolwill be moved to the new PSE.

ZESM:<pool id>,<PSEI>;

Example

Modify the dynamic Abis pool whose id is 2 so that the new packet serviceentity is 3.

ZESM:ID=2,PSEI=3;

Further information

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Modifying a dynamic Abis pool

. Alarm 3068 EGPRS DYNAMIC ABIS POOL FAILURE is raised if thedynamic Abis pool creation fails for some reason. For moreinformation on the possible causes of the failure and recoveryinstructions, see Failure Printouts (2000-3999) under Reference/Alarms in the PDF view.

. For instructions on modifying the dynamic Abis pool information of aTRX, see Activating and Testing BSS9006: GPRS under Test andactivate/Data in the PDF view.

. Activating and Testing BSS10083: EGPRS under Test and activate/Data in the PDF view

. Activating and Testing BSS20106: Packet Control Unit (PCU2)Pooling under Test and activate/Data in the PDF view



3 Deleting a dynamic Abis poolBefore you start


When deleting a dynamic Abis pool (DAP), the BSC turns off the GPRStraffic from the logical packet control unit (PCU) where the deleted poolexists. The BSC downgrades all packet switched traffic channels from thePCU and upgrades these traffic channels to packet switched use again.Deleting an existing DAP of a PCU causes a reallocation of the remainingdigital signal processor (DSP) resources in the PCU. This shortinterruption ensures optimised PCU DSP resource usage for each DAPconnected to a specific PCU.

Steps

1. Check that there are no TRXs attached to the dynamic Abis poolthat you want to delete (ESI).

ZESI:ID=<pool id>:TRXS;

You cannot delete the dynamic Abis pool if there are TRXs attachedto it.

Example

ZESI:ID=1:TRXS;

2. Detach TRXs from the dynamic Abis pool.

If there are TRXs attached to the dynamic Abis pool, detach them.For more information on detaching a dynamic Abis pool from a TRX,see Activating and Testing BSS9006: GPRS under Test andactivate/Data in the PDF view.

3. Delete dynamic Abis pool(s) (ESG).

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Deleting a dynamic Abis pool

ZESG:ID=<pool id>;

Example

Deleting one dynamic Abis pool:

ZESG:ID=1;

Deleting several dynamic Abis pools:

ZESG:ID=1&4&&7;

Further information

Alarm 3068 EGPRS DYNAMIC ABIS POOL FAILURE is raised if thedynamic Abis pool creation fails for some reason. For more information onthe possible causes of the failure and recovery instructions, see FailurePrintouts (2000-3999) under Reference/Alarms in the PDF view.



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