nortel_v16_bss_im_v9
TRANSCRIPT
1 Nortel Confidential Information
Nortel V16 validation for T-Mobile USAIM campaign management with WQAIM BSS functionality introduction
November 7, 2006Version 9
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Workshop Agenda
> Introduction> IM campaign management with Nortel BSS V15
• CPT-based scripts and associated process
> IM functionality with Nortel BSS V16• BSS and OMCR operational considerations
> WQA platform introduction• WQA tool administration and overview
> WQA-IM post-processing module• Principles, inputs, outputs
> WQA in the end-to-end T-Mobile RF Engineering Process• Workflow, process considerations
> WQA-IM hands-on demonstration• Using field IM campaign data from NY
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> End-to-end frequency planning process
IntroductionScope of workshop
RF Engineering
inputs
IM campaignexecution
IM campaign
Post-processing
Frequencyplanning
Tool(AFP)
Frequencyplan
change
Engineering activity
Network activity
Nortel tools or features delivered to T-Mobile
V16 IM WQA FPC
IMC/I
Focus of this chapter
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Agenda
> BSS functionality overview
How the feature works and does without user intervention
> BSS operational aspects
What the feature requires as user inputs
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IM campaign management in V16BSS functionality overview
> V16 introduces a BSS-based solution for the Interference Matrix• Feature 16411
> Regular subscriber measurement reportsare used to build C/Idistributions between(BSiC/BCCH) couples
> XML files generated atSDO for further post-processingwith the WQA tool
WQA
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BSS functionality descriptionNeighbor cell management (1/2)
> Main inputs to the IM campaign :• List of cells which will perform IM measurements• List of BCCH frequencies to scan
> The campaign is based on GSM standard mobile reporting procedure> The BSS will fill SYSINFO messages up to their maximum capacity of
32 “neighbors” , so as to encompass :• Real neighbors (declared at OMCR for handover purposes)• Fake neighbors (not declared as real neighbors, based on the BCCH list)
> Handovers to fake neighbors are prevented thanks to the usage ofdissuasive radio parameters (e.g hoMargin = 63)
> The same neighbor list (real+fake) will be kept during an IM cycle• Upon completion of cycle, original “real” neighboring plan is reinstated
> The number of cycles to perform will therefore depend on :• Actual real neighboring declarations (and associated BCCH frequencies)• Depth of the BCCH scan list
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BSS functionality descriptionNeighbor cell management (2/2)
> Example : • BCCH scan list : 100 frequencies• Average of 17 real neighbor cells declared per serving cell• 6 cycles are required to collect measurements on all 100 frequencies
Cycle #1(32)
Cycle #2(32)
Cycle #5(32)
Last Cycle #6(25)
Declared Neighbors
FakeNeighbors
100 Frequencies to scan
15 15 15 8
17
15
17
15
17
15
17
8
17+15+15+15+15+15+15+8 = 100
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BSS functionality descriptionCycle management (1/2)
> A given cycle is associated with 1 neighboring plan
> Upon completion of the cycle, the data is transferred from BTS to BSC, and then from BSC over to the SDO
IM start1 per BSC Cycle 1 with neighbouring plan 1
Start Meas.End Meas.M
eas.
D
urat
ion
Meas. period
…
Cycle p with neighbouring plan p
Data Collection Report
Post Processingproduct
OMC-R BSS
Mobile
Cyc
le d
urat
ion
Dataretrieval
Neighbouring plan setting
Data Collection Report
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BSS functionality descriptionCycle management (2/2)
> The timing of the cycle mechanism is set via a set of configurable parameters :
• ciBgtMeasurementTime• representing the time of start of the first measurement cycle,
• ciBgtReportingCycle• representing the duration of one measurement cycle and consequently the
periodicity of the report to OMC,• Configured in practice in increments of 20 minutes
• ciBgtMeasurementDuration• inside a period of one cycle, the operator can specify the duration of the real
phase of measurement.• Configured in practice in increments of 15 minutes
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BSS functionality descriptionMessage exchange (1/2)
> Cycle start> BSC
automaticallypopulatesSYSINFOwith fakeneighbor infowithoutuser interventionnor scripts
OMC-RW-NMS BSC BTS MS
First Cycle
IM_Freq_Meas TGE
Ack TGERGE
(Ext_)Current Cell Params
ciBgtReportingCycle timer start
Meas Report on real neigh
(Ext_)Neigh Cell Params
(real + Fake freq)
SysInfo 5, 5bis, 5ter, 2, 2bis, 2ter, 13
(BA list real + Fake freq)ciBgtMeasurementDurationtimer start
ciBgtMeasurementTime
ciB
gtM
easu
rem
entD
urat
ion
Meas Report on real+fake neigh
Meas Report on real+fake neigh
Meas Report on real+fake neigh
ciBgtMeasurementDurationtimer reset
start distribution req
start distribution ack
Meas Report on real+fake neigh
stop distribution ack
stop distribution req
All TRXs
BSC BTS MS
First Cycle
IM_Freq_Meas TGE
Ack TGERGE
(Ext_)Current Cell Params
ciBgtReportingCycle timer start
Meas Report on real neigh
(Ext_)Neigh Cell Params
(real + Fake freq)
SysInfo 5, 5bis, 5ter, 2, 2bis, 2ter, 13
(BA list real + Fake freq)ciBgtMeasurementDurationtimer start
ciBgtMeasurementTime
ciB
gtM
easu
rem
entD
urat
ion
Meas Report on real+fake neigh
Meas Report on real+fake neigh
Meas Report on real+fake neigh
ciBgtMeasurementDurationtimer reset
start distribution req
start distribution ack
Meas Report on real+fake neigh
stop distribution ack
stop distribution req
All TRXs
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BSS functionality descriptionMessage exchange (2/2)
> Cycle end> BSC
automaticallyrestoresSYSINFOwith realneighbor info
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BSS functionality descriptionMeasurement gathering & reporting (1/3)
> What is measured ?• Serving cell i, neighbor cell j (real or fake)
> IM measurements are done on 1 TRX per sector> TRX selection :
• Performed at the beginning of each cycle (not campaign)• Upon sending the START_DISTRIBUTION message
• The BSC selects the TRX that carries the TDMA with the greatest number of ongoing circuit speech calls (excluding signalling, including pre-empted PDTCH)
• Between two TDMAs that have the same number of such calls, the BSC chooses first the TDMA with the greater AMR HR priority, then the TDMA with the lowest number of PDTCH, and then in case of still equality, with the lowest TDMA number.
• If BSC cannot find a TRX that satisfies the criteria given here above, BSC does not send the activation to the BTS and the cell will not report any measurement for this cycle
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BSS functionality descriptionMeasurement gathering & reporting (2/3)
> What is reported ?
• A rescaling factor is used for Abis bandwidth optimization allowing to encode any counter value into one byte (with a value below 255).
> For each cycle, C/I distributions are stored on the TRX then reported to BSC
• Distribution data for up to btsMaxNbofDistribPerCycle = 150 BSIC/BCCH pairs are stored - TRX memory constraint
• Data is reported to the BSC upon completion of the cycle, upon receipt of the STOP DISTRIBUTION message
• Only the MaxNbofDistribPerCycle = 113 most represented BSIC/BCCH couples are reported to the BSC (i.e the distributions based on highest amount of samples) – Abis load constraint.
• MEAS Distribution Report messages sent every 5 seconds to BSC, with 6 distributions per message
• Worst case : 113 distributions are reported 19 messages 95 seconds.
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BSS functionality descriptionMeasurement gathering & reporting (3/3)
>Transfer of data from BSC to OMC :• At BSC level, all Abis messages from cells belonging to same CG (cell-
group, from TMU standpoint) are concatenated• Once all measurement distribution reports are received for a particular CG,
the BSC closes the file and is sent to the OMC/SDO.• An event may affect a cell in the CG (such as trap or lock), leading to the
repetition of the cycle. As such, all CG files may not be closedsimultaneously
>SDO data storage :• Files received from the BSCs are processed and broken down into :
• 1 XML file per cell , per cycle. • Each XML file is optionally compressed using .GZ format (choice at SDO GUI)
• An automated daily TAR process compiles ALL present day XML files into a single TAR archive,
• Nightly procedure (per SdoDailyTimeTransfer parameter)• An “on-demand TAR” option is also available via the SDO MMI
• In case WQA access to the CIBGT data is required before the nightly archiving
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> Defense scenarios and impact on IM campaign• TRX lock or trap :
• Data for the ongoing IM cycle is lost• Data gathering, for this TRX, will resume upon next occurrence of ciBgtReportingCycle• there is only one cycle repetition allowed
• BTS lock or trap :• Data for the ongoing IM cycle is lost• Data gathering, for this BTS, will resume upon next occurrence of ciBgtReportingCycle• there is only one cycle repetition allowed
• BSC TMU reset :• Data for the ongoing IM cycle is lost, for all CGs supported by this TMU• Data gathering, for the served CGs, will resume upon next occurrence of ciBgtReportingCycle• there is only one cycle repetition allowed
• BSC restart :• Data for the ongoing IM campaign is lost • Data already uploaded at the SDO is useless• To restart the campaign, an IM ABORT command is required, followed by an IM launch.
• OMC server restart :• Process in the BSS is not stopped.
BSS functionality descriptionDefense scenarios
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BSS operational aspectsFeature pre-requisites> Feature restrictions :
• Hardware :• Not available on S2000 & S4000 BTS products
• Software • Requires V16 software on BSC & BTS
• IM campaign can be launched on a V16 BSC with V15 BTS • There will be no reports from V15 BTS
> Inputs gathering :• List of cells on which IM measurements are to be performed• List of BCCH to be scanned
• These inputs can be entered manually at the OMC MMI or be prepared in external files to be uploaded.
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> From the OMCPerformance Menu
BSS operational aspectsIM campaign activation at OMC (1/9)
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BSS operational aspectsIM campaign activation at OMC (2/9) File menu
Allows to load/save IM campaign dataEdit menuTo add cells in the campaignBSC menuTo set the IM campaign general parameters
Add buttonto add BSCs in the campaign
Check buttonTo run semantic checks
Estimate buttonto obtain an evaluation of the campaign duration
Launch buttonto activate the campaign
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> Manual setting of the general campaign parameters (applicable at BSC level) :• Dialog window :
• ARFCN (range or list)
• CiBgtReportingCycle• 20min increments
• CiBgtMeasurementTime• CiBgtMeasurementDuration
• 15min increments• Fake BSIC
BSS operational aspectsIM campaign activation at OMC (3/9)
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BSS operational aspectsIM campaign activation at OMC (4/9)
> Alternative :Import of an input file(“aCIBgtCfg” file)
Example Format
Campaign parameters for BSC 244 :CiBgtReportingCycle = 12*20min = 4HCiBgtMeasurementTime = 960min = 16h00 (= 4pm)CiBgtMeasurementDuration = 14*15min = 3H30minFakeBSIC : BCC = 0 , NCC = 0All ARFCN listed : 541,554,555,558,621,654,687
Note : the input file may also only contain the [BTS] portion,in which case the system will only populate the list of cells
for the campaign.This smaller file is referred to as <Network_BTS>in the documentation.
The remaining IM campaign parameters (timing, frequencies to scan) can then be configured via the GUI.
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BSS operational aspectsIM campaign activation at OMC (5/9)
> Pre-checks (1/2) : Consistency checks between network configuration and interference matrix inputs • parent btsSM of the cells that will be activated is hardware compatible• cells are all parented to a BSC release V16, not locked• Interworking with CDA (same BSC) and RMD (same cells)• ciBgtReportingCycle > ciBgtMeasurementDuration• Interference Matrix is not already running for every BSC• ARFCN are all in same band (e.g 1900)• No more than 100 BCCH frequencies are required.• Cells do not already have 32 real neighboring cells.
• If one cell already has 32 real neighbors, the operator is warned and asked whether to keep the cell in the list. If the operator decides to keep the cell in the list, the check must not be blocking during execution.
• It is advised to limit the number of neighbors to 31 to leave room for measurements on 1 “fake” BCCH
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BSS operational aspectsIM campaign activation at OMC (6/9)
> Pre-checks (2/2) : example
Concurrent usage of RMD
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BSS operational aspectsIM campaign activation at OMC (7/9)
> Estimation of campaign duration is provided prior to launch
List of BCCH frequencies to
scan
Real NeighborPlan
Number of cycles
Timing parameters
Total IM Campaign duration
Assumption : each cycle is executed once
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BSS operational aspectsIM campaign activation at OMC (8/9)
> Launch • Via MMI button
> Abort• From BSC menu
> Check status • At MMI
> Dynamic flags :• 2 levels :
• interferenceMatrixRunningOnBts• interferenceMatrixRunningOnBsc
• Displayed at MMI via Get command
> Activation status :
End of IM campaign can be detected wheninterferenceMatrixRunningOnBsc is back at “NO” on all BSCs
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BSS operational aspectsIM campaign activation at OMC (9/9)
> Self-enforced “network freeze” : the following activities are prevented by the system, during execution of the IM campaign• BTS reparenting
• As this require the bts object to be deleted on source BSC• Neighbor declaration
• Creation/deletion of neighbors prohibited for cells part of IM campaign• Change of parameters other than BSIC/BCCH allowed on existing neighbors
• RMD on same cells where IM campaign is running• BTS processing limitation
• CDA on same BSC involved in an IM campaign• BSC disk capacity limitation
> Frequency plan change• (Non-BCCH) TRX additions are possible (but lock of bts cycle lost)
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CDA/RMD/IM/CT/CPT concurrent usage possibilitiesV16
Concurrent usage is possible without restrictionsConcurrent usage is possible - restriction of usage to a subset of cells may apply*Concurrent usage is not recommended / not technically possible
Limitations applicable to individual features : -CDA : activation on max 80 cells/BSC-CPT : max number of 6 cells/BSC, max 36 traces/BSC-CT : max 12 traces/BSC
*Note : ad-hoc study required, depending on OMC configuration
CDA RMD IM CT CPT
CDA BSC basis
RMD Cell basis
IM BSC basis Cell basis
CT
CPT
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BSS operational aspectsSDO data storage
> Compression of IM XML files• ON, by default• Configurable
via SDO GUI• Data Format menu
> Archiving of IM XML files• Automated Nightly “TAR” (@2.00AM)
• SdoDailyTimeTransfer parameter• Manual archiving triggered
via :• SDO GUI
• Archive menu• tarXML command
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Main outputs> Interference Matrix C/I distributions (XML files)
• Before archiving :• Naming : <Type><Startdate>.<Starttime>-<Endtime>_-<sessionId>_CELL.<CGI>_-
_<cycleId> • Example : A20050101.1400+0200-1415+0200_-1a9f_CELL.64f00001ab0001_-_03• Location : /SDO/data/CIBgt/YYYYMMDD/<networkId>/<sessionId>/<bscId>/
• After archiving of all XML files produced during the day :• Naming : <Type><Startdate>.<Starttime>-<Endtime>.tar • Example : D20050101.1400+0200-2345+0200.tar • Location : /SDO/data/CIBgt/compressed
> Interference Matrix Configuration File• Naming : aCIBgtCfg_<sessionID>_<time><deltaUTC> • Example : aCIBgtCfg_1a9f_1200+0200 • Location : /SDO/data/CIBgt/YYYYMMDD/<networkId>/<sessionId> • Note : this file can be created manually as input to the IM campaign as well
> Network Configuration files• Generation is independent from IM• Naming :
• aNETWORK_BTS.hhmm (All cell-based parameters)• aNETWORK_ADJCHO.hhmm (Neighbor declarations)
• Location : /SDO/data/network/ YYYYMMDD /<NetworkId>
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IM functionality in the BSSDocumentation references
> Functional Note :• Description of the feature from a Design standpoint• Reference document PE/SYS/DD/0428, v01.17• Located in the T-Mobile File Exchange @ mynortelnetworks.com
> NTP Operational documentation• Description of the IM activation from an Operations standpoint• NTP : Nortel GSM OMC-R Commands Reference - Configuration,
Performance, and Maintenance menus (411-9001-129)• Section 2.10 : «Interference Matrix Launcher »• Available via Helmsman Express
> SDO specifications• SIE OMCR Data Server – XML part : PE/OMC/DD/014022• SFS OMCR Data Server : PE/OMC/DD/000103• Located in the T-Mobile File Exchange @ mynortelnetworks.com