[Seminar5] CS Paging Coordination in the BSS

B11 MR1 Ed1.0Seminar of GSM Network EngineeringSupport of CS Paging Coordination in the BSSRamy AdelMarch 2010

Alcatel-Lucent InternalProprietary Use pursuant to Company instruction.

Reference Documentation

SFDEnhanced DTM & Paging Coordination Release B11 (3BK 10204 0104 DTZZA)Dual Transfer Mode (3BK 10204 0032 DTZZA)Step 2Paging, Access Grant Control and Notification, B11 (3BK 11202 0495 DSZZA)(E)GPRS Radio Interface - RRM Sublayer PCC (3BK 11202 0513 DSZZA), chapter 5.3MEMOB11 Support of Paging coordination in the BSS (Wireless/GSM/R&D/SYT/ rma/036.2007 Ed.02)MISC.DTM Functional Specification Release B11 (3BK 11202 0490 DSZZA)B10: BSS Architecture Service Guideline (3DF 01903 8010 VAZZA 01)


AgendaFeature OverviewFeature aim and principleRelated parametersActivation StrategyRules and recommended parameter settingsCompatibility with previous HW generationsFeature AssessmentMonitoring methods and Expected ResultsField Trial Results:CMCC B11 MR1 Ed1.0 FO Tests ResultsVelizy On-air Platform Tests ResultsConclusionAnnex


Feature Overview 1


Without CS paging Coordination and while in Packet Transfer Mode (PTM):Class B MS (popular MSs) can lose some CS Paging Messages if the duration of the packet transfer is longer than the duration of the repetition of CS paging messages from the MSC side, i.e. MS unreachable.This is mainly because the CS paging messages will be transmitted on the PCH channel while in PTM the MS is consuming (receiving / transmitting) the PDTCH/PACCH channels. Feature OverviewFeature aim and principle Importance of CS paging Coordination (1/2)CLASS B MSBTSBSCMFSMSCSGSNGbGs CS PAGINGAterAbisTCAterAPTMPDTCH/PACCHCS paging messages may be lost, i.e. MS is unreachablePCHNetwork Modes of Operation and MS Classes


Alcatel-Lucent implementation of the Dual Transfer Mode (DTM) feature assumes the support of CS paging coordination to be able to receive a DTM call during a PS transfer.MS shall receive CS paging while in PTM to go to dedicated mode.

With the support of CS paging coordination:The CS paging performance is increased, ensure that the MS can receive CS paging even during the PS transfer PTM (CS paging will be sent on the PACCH).Full DTM feature support is feasible, since it will be possible to receive a DTM call during PS transfer.Note: DTM feature was not tested in any FO and it still needs an FMA (First Market Application) to be open for commercial use.Feature OverviewFeature aim and principle Importance of CS paging Coordination (2/2)B10 DTM Overview


Feature OverviewFeature aim and principle CS Paging Coordination Strategies (1/2)3GPP foresees two ways to support paging coordination:CS Paging Coordination in the SGSN (Network Operation Mode I NMO I) - Implement Gs interface between the CS and PS Core (MSC and SGSN)

- CS paging messages for MS in PTM are transferred from the MSC to the SGSN through the Gs interface.- Afterwards, the SGSN forwards the paging messages (through MFS) on the PACCH of PDCHs allocated to this MS.MSBTSBSCMFSMSCSGSNGbGs CS PAGINGAterAbisTCAterAWith CS Paging Coordination in the SGSNGs InterfacePACCHCS paging coordination is performed in SGSN through Gs Interface (NMOI)


Feature OverviewFeature aim and principle CS Paging Coordination Strategies (2/2)CS Paging Coordination in the BSS (NMO II) Our Concern

- The BSC sends the received CS paging messages (from the MSC) on the PCH and forwards it to the MFS through CS paging Coordination Request message.- Afterwards the MFS sends it on PACCH whenever MS would be performing a packet transfer (PTM) by searching the requested MS IMSI in the IMSI vs MS Context table created internally in the MFS for all MSs in PTM only. MSBTSBSCMFSMSCSGSNGbGs CS PAGINGAterAbisTCAterAWith CS Paging co-ordination in the BSSPACCHPCHCS paging coordination is performed in the BSS, Gs interface is not used (NMOII)CS Paging Coordination Request (IMSI)IMSI vs MS-Context table SearchFeature Summary


Feature OverviewFeature aim and principle - Before B11 and Feature RationaleCS paging coordination in SGSN (before B11)To increase the CS paging performance (no CS paging messages are lost during PTM) Gs interface is needed in the core network between the SGSN and the MSC.To fully support DTM feature (MS shall receive CS paging while in PTM to go to dedicated mode), Gs interface is assumed to be implemented in the core network.Network Mode of Operation 1 (NMOI). CS paging coordination in BSS (B11)To increase the CS paging (no CS paging messages are lost during PTM) CS paging Coordination in BSS feature is activated. To fully support DTM feature (MS shall receive CS paging while in PTM to go to dedicated mode), CS paging coordination in BSS feature is activated.Network Mode of Operation 2 NMOII. NMOIII is no longer used in ALU BSS (corresponds to the use of master PDCH).As some customers (ex: CMCC) are not interested in the usage of Gs interface: Due to high number of core network providers, a high number of interoperability tests is needed.This feature was developed in the BSS as a substitute of the Gs interface in performing the CS paging coordination and therefore saves Core network operational costs.


CS Paging Coordination in the BSS:3 Steps are followed:

The MSC sends CS paging requests to the BSC.BSC forwards CS paging requests to the MFS using BSCGP GSL (after filtering some info) and broadcasts normally all CS paging requests to MS through the PCH channel (for all cells corresponding to the paging area managed by this BSC).MFS sends these paging requests to the MS through the PACCH of the cell where the MS camps on (when applicable, MS in PTM).Feature OverviewFeature aim and principle General Overview


When the BSC received a paging message from the MSC:A. It sends the paging messages on the PCH (BSC-BTS paging).B. It applies some filtering and sends it to the MFS (CS paging to MFS).For the first point, we have 2 scenarios for single and multiple paging command cases (G2 BSC and Mx BSC respectively).Case 1: Single Paging command (G2 BSC)

The MSC will send the paging request to all concerned BSCs in a given paging area (LAC).Feature OverviewFeature aim and principle Details BSC processing of incoming CS paging(1/5)

Access Grant from the MSn which

answer to the Paging Request

PAGING COMMAND (MS1, pgr1)

CS paging to MFS

BTS

Start T3113 for MSn

PAGING (MS1)

MSC

MFS

BSC

Stop T3113

for MSn

Paging response (MSn) on SDCCH

PAGING COORDINATION REQ


Feature OverviewFeature aim and principle Details BSC processing of incoming CS paging(2/5)Case 2: Multiple Paging Commands (Mx BSC)

When NB_MAX_MSG_MULTIPLE_PAGING_CMD (5) (if >1) Paging commands (received from the MSC) have been buffered or when T_SEND_MULTIPLE_PAGING_CMD (50 ms) elapses, the buffered Paging commands are sent on both Abis (as in B10) and GSL (new for B11, due to the introduction of this feature).

T_SEND_MULTIPLE_PAGING_COMMAND

NB_MAX_MULTIPLE_PAGING_COMMAND PAGING commands buffered (or T_SEND_MULTIPLE_PAGING_COMMAND timer elapses)

Start T3113 for MS5

PAGING (MS5)

Scenario continues as in single Paging case

MULTIPLE PAGING COMMAND (MSn, pgrk)

CS paging to MFS

BTS

Start T3113 for MS1

PAGING (MS1)

MSC

MFS

BSC

PAGING COORDINATION REQ


B. CS paging to the MFSFiltering:Reason: to prevent sending useless CS paging requests to the MFS, therefore to save the GSL load and at the same time it should not increase the BSC processing load (especially in G2 BSC where BSC load is critical).BSC provides only IMSI to the MFS (paging area is not included) to decrease the GSL load.CS paging requests are sent to the MFS only if EN_BSS_PAGING_COORDINATION flag is enabled (per BSC level). To handle such filtering per cell is risky concerning the BSC processing load, especially in case the paging area is a list of cells where not all of them have this flag activated.This is the reason for managing CS paging coordination on the BSC level.Note: The BSC does not filter upon the GPRS operational state because it most likely to have GPRS supported for all the cells of a BSC, i.e. filtering can then load the BSC without a big benefit. The same applies for the cell operational/administrative states (no filtering).Feature OverviewFeature aim and principle Details BSC processing of incoming CS paging(3/5)


B. CS paging to the MFS (Contd)II. BSC paging message to the MFSNew message is introduced in the BSCGP to forward CS paging to the MFS PAGING COORDINATION REQUEST and it is used for both Single Paging command (1 request) and Multiple Paging command (several requests).

In 3GPP TS 48.008, the IMSI is a mandatory field in the PAGING message from the MSC, even though the TMSI has to be used to page the MS.TS 48.008 states that IMSI can be used only exceptionally i.e. when TMSI is unknown).In BSS paging coordination, all paging requests can be transferred to the MFS; i.e. the MSC sends the PAGING message with both IMSI and TMSI. The BSC transfers both TMSI and IMSI to the MFS in the paging coordination message, the MFS has then to page with this TMSI.Feature OverviewFeature aim and principle Details BSC processing of incoming CS paging(4/5)New BSCGP msg.


Notes:In case of multiple paging command:If the CS paging request for a given IMSI was previously stored in the PAGING COORDINATION REQ message, further requests to this IMSI will be discarded.Can be considered as another type of filtering to minimize the GSL load.The cell parameter PAG_BAR only concerns barring the CS paging on the PCH channel.It does NOT prevent the MS from being paged on the PACCH channel.This parameter does NOT affect CS paging coordination while the MS is in PTM (either for BSS or SGSN paging coordination).Feature OverviewFeature aim and principle Details BSC processing of incoming CS paging(5/5)


CS Paging Coordination in the BSS:3 Steps are followed:

The MSC sends CS paging requests to the BSC.BSC forwards CS paging requests to the MFS using BSCGP GSL (after filtering some info) and broadcasts normally all CS paging requests to MS through the PCH channel (for all cells corresponding to the paging area managed by this BSC).MFS sends these paging requests to the MS through the PACCH of the cell where the MS camps on (when applicable, MS in PTM).Feature OverviewFeature aim and principle General Overview


When CS Paging Coordination is performed in the SGSN:The MFS assumes that the SGSN always provides for the paged MS in PTM mode the most accurate location it is aware of (cell BVCI).This allows the MFS to easily find the corresponding MS context without knowing the MS IMSI.However when CS Paging Coordination is performed in the BSS:Only the IMSI is provided to the MFS (no Paging Area is provided) by the PAGING COORDINATION REQ messages sent by the BSC.MFS has to build and maintain for all MS in PTM mode a set of IMSI vs MS Context relationships, i.e. the MFS is able to find the MS context (contains the cell for PACCH paging) provided that EN_BSS_PAGING_COORDIATION parameter is enabled on this BSC.Feature OverviewFeature aim and principle Details MFS processing of received IMSI (1/4)


Notes about the IMSI vs MS context table:When the MS leaves the PTM, the corresponding IMSI vs MS Context entry has to be deleted.When the MS enters the PTM mode, the IMSI has to be retrieved.In case of a DL TBF, the IMSI will be picked from a DL LLC PDU.In case of an UL TBF, a Radio Access Capacity Update procedure has to be performed at completion of UL TBF establishment to speed-up the IMSI retrieval.That is why it is highly recommended to enable the BSC parameter EN_RA_CAP_UPDATE prior to the activation of the CS paging Coordination in the BSS.Feature OverviewFeature aim and principle Details MFS processing of received IMSI (2/4)


When the MFS receives a PAGING COORDINATION REQ message from the BSC, the MFS shall:1. Browse through the IMSI MS Context table.2. If the IMSI is found (i.e. MS is in PTM mode) and the MS context is known, the MFS will send the CS paging message on the corresponding PACCH.3. Otherwise (IMSI not found) the MS is not in PTM, MFS will discard the CS paging.In case of a G2 BSC, the PAGING COORDINATION REQ always contains a single IMSI (single paging command).In case of an Mx BSC, the PAGING COORDINATION REQ can contain more than one IMSI (according to the BSC parameters NB_MAX_MSG_MULTIPLE_PAGING_CMD and T_SEND_MULTIPLE_PAGING_CMD).NOTE:No Ack message is managed as a response for the PAGING COORDINATION REQ. However the extra GSL load can be monitored through the GSL PM counters (please refer to monitoring methods section).Feature OverviewFeature aim and principle Details MFS processing of received IMSI (3/4)


The following diagram summarizes the IMSI processing and CS paging message forwarding on the PACCH (if MS is in PTM mode):

Note: IMSI vs. MS context is stored in each GPU, thats why when the MFS receives the Paging Coordination REQ message, there will be for each paging IMSI three possible cases:1. IMSI is found: the paging message is sent to the MS via the BTS on PACCH.2. IMSI is not found: the Paging REQ will be broadcasted to all other GPUs corresponding to this BSC (Multi-GPU BSC).3. IMSI is not found in all GPUs corresponding to this BSC: the MFS discards the Paging Request.Feature OverviewFeature aim and principle Details MFS processing of received IMSI (4/4)


Alcatel-Lucent solution Summary: MFS will maintain a table containing the IMSI vs MS-context for all the mobiles in PTM mode (MFS is capable of keeping track of the mode of the GPRS attached MSs , PTM or PIM); IMSI of the paged mobile will be sent by the BSC.To perform the previous 3 steps:The BSC receives the CS paging messages from the MSC.It forwards it to the BTSs on the PCH.The BSC does some filtering for the CS paging messages contents and send the IMSI to the MFS through a Paging Coordination Request message.The MFS, using the key the IMSI, will browse through its IMSI vs MS-context database. If the IMSI is found then the MS context is known.The MFS sends the CS paging messages on the corresponding PACCH.Therefore, CS paging messages can be received while the MS is in PTM.Feature OverviewFeature aim and principle - Implemented Solution Summary


Paging channel that should be used by the BSS (depending on the state of a GPRS-attached DTM MS and the paging coordination solution):Feature OverviewFeature aim and principle - Updated Paging Rules for DTM MS


Feature OverviewRelated ParametersNew Parameters:

On the air interface: Some messages will be affected by the EN_BSS_PAGING_COORDINATION O&M parameter:The BSS_PAGING_COORDINATION field in the DTM ASSIGNMENT COMMAND, PACKET ASSIGNMENT and SI TYPE 13 messages will be set according to the value of EN_BSS_PAGING_COORDINATION.


Activation Strategy 2


The feature is optional.Activation is done at the BSC level.Activation is done from the OMCR using the parameter EN_BSS_PAGING_COORDINATION (TRUE); then it is sent to both BSC and MFS.The network_mode_operation 1 should be 2 (checked also by the OMC).Remark: NMOIII is no longer used (MPDCH).NMOI cannot be used with this feature (it only concerns the presence of Gs interface in the core network).Remark: Two ways of CS paging coordination can not be handled simultaneously per BSC. The feature can be used independently from the activation of the DTM feature:This B11 feature can also be used to improve the CS paging performance while the MS is in packet transfer mode (PTM) (MS will be paged faster on average on PACCH that on PCH, as described in the previous slides).If EN_DTM is enabled at least in one cell in a given BSC, it is highly recommended to activate this feature for this BSC (NMO1).Activation StrategyRules and recommended parameter settings (1/2)


The feature makes sense if GPRS is enabled in at least on cell in the BSC.If a BSC is connected to a MFS but GPRS is not operational for all the BSC cells it is recommended to set EN_BSS_PAGING_COORDINATION to Disabled for this BSS.GPRS through satellite connection on Abis or Ater interface feature is not compatible with the feature (checked by OMC) because of the GSL load risks.GSL overload is a problem only if Ater satellite link is used (no problem if Abis satellite link is used with a terrestrial Ater link).But the Round_trip_delay parameter used for the check is related to the whole MS-MFS path and therefore it does not allow to distinguish Ater from Abis.Round_trip_delay should be < 500 msec (MS-MFS path) for all the cells for the BSC.It is highly recommended to activate Radio Access Capability update feature EN_RA_CAP_UPDATE (BSC parameter) prior to the activation of the CS paging Coordination in the BSS (not checked by the OMC).Activation StrategyRules and recommended parameter settings (2/2)


Based on CMCC B11 MR1 ED1.0 FO and the issue discovered:In case Paging Repetition is enabled at the core (MSC/VLR) side, there is a very very low risk to have a loss of CS calls during pings with long pause durations. The RA Capacity Update procedure (EN_RA_CAP_UPDATE) should be enabled to minimize a bit the losses of CS paging requests (which is triggered at completion of TBF UL establishment to speed-up the IMSI retrieval).For more details about this issue please consult ANNEX F, it will also be discussed in CMCC B11 MR1 ED1.0 test results section.

Activation StrategyRecommended setting based on experimentation in CMCC B11 MR1 ED1.0 FOANNEX F


The feature does not have a software impact on all the BTS generations, all TRE generations and all transcoder generations.The feature only impacts the software of the BSC and the MFS.BSC: CS Paging filtering and PAGING COORDINATION REQUEST message building.MFS: PAGING COORDINATION REQ processing, IMSI MS Context relationships building & browsing.Restrictions & Limitations- There is an indirect impact since Multiple Paging on GSL is NOT supported by G2 BSC as previously described.

Activation StrategyCompatibility with previous HW generation and restrictions


Feature Assessment 3


Monitoring Methods and Expected Results


Two main tests categories are used to test the feature on-field:1. Functional unitary tests: Purpose:to validate the correct functionality of the feature to serve previously discussed feature interests:To generally increase the CS paging performance.To achieve Full DTM feature support.i.e. ensuring that the MS can receive CS paging during PS transfer (PTM) either for DTM calls or for normal CS calls (interruption of PS service).to monitor PS performance after feature activation, i.e. data performance non-regression in terms for FTP throughput and Ping success rate and RTT.2. Statistical tests:Purpose: to ensure non-regression of the main CS and PS QoS KPIs after feature activationto ensure that no regressions occur in equipment availability or stability.to check the feature specific indicators; GSL Paging Coordination Requests.to monitor/estimate GSL load after feature activation (BSCMFS direction). Feature AssessmentMonitoring methods Main Tests CategoriesTests Pre-requisites


Feature AssessmentMonitoring methods Functional Unitary Tests SummaryAll the above tests are staticUnitary Tests Expected Results

Type of testsAim & Procedure of the testsParameter SettingCS performance without DTM featureTo assess the benefit of the feature in increasing the CS paging performance during an on-going PS session i.e. terminating CS call success rate.Test Procedure: Perform 15 random terminating CS calls towards trace MS during different PS sessions: A DL FTP session (5MB, EDGE Mode). An UL FTP session (2MB, EDGE Mode). 101 Iterations PING session with small PING size 32B with different pause durations between each 2 iterations (0, 1, 2 & 5 sec). 101 Iterations PING session with big PING size 1460B with different pause durations between each 2 iterations (0, 1, 2, & 5 sec)EN_BSS_PAGING_COORDINATION = FALSE/TRUEEN_DTM = FALSECS performance with DTM featureTo identify the gain brought by feature to receive CS paging while MS is in PTM to successfully establish a DTM call, i.e. DTM call success % while MS is in PTM.Test Procedure:Same procedure as the previous category but with DTM activated.EN_BSS_PAGING_COORDINATION = FALSE/TRUEEN_DTM = TRUENon-regression PS performanceTo ensure the non-regression of the PS performance after feature activation in terms of throughput (FTP), Ping Success rate and RTT (Ping).Test Procedure: Perform DL FTP Transfers (using trace MS ex: Nokia N95) for 5MB file in EDGE mode. Perform UL FTP Transfers (using trace MS ex: Nokia N95) for 2MB file in EDGE mode. Perform PING Session (using trace MS ex: Nokia N95): Small Ping Size: 32B, 101 iterations with 0 sec pause & with 5 sec pause. Big Ping Size: 1460B, 101 iterations with 0 sec pause & with 5 sec pause.EN_BSS_PAGING_COORDINATION = FALSE/TRUEEN_DTM = FALSE


Feature AssessmentMonitoring methods Statistical Tests Details and Expected results (1/6)

1. QoS follow-up: Expected Results:Non-regression of the main CS and PS QoS indicators after feature activation.GPRS acceptable release due to suspend cause (GPRS_xL_TBF_release_suspend) is subject to increase after feature activation; since with the new feature there is a higher chance to suspend the on-going GPRS sessions to serve the incoming CS calls.2. Stability and unavailability follow-up: Expected Results:No regressions in the GSM/GPRS/TRX/SS7 availability after feature activation.No regressions in BSC/BTS/Cell stability after feature activation.



3. Feature Specific Indicators check:Two feature specific counters are implemented in B11 MR1 ED2 upon NE request (CR: 3BKA20CBR275762). Before that, there were no dedicated counters for this feature.Accordingly, pre-B11 MR1 ED1:We could can only estimate the number of CS paging IEs in PAGING COORDINATION requests sent on GSL by the help of other existing BSC/MFS counters.It is an approximation for the paging coordination messages sent on GSL not an accurate value.Noting that we still do not have an indication that the feature is working, because these other counters will always have values whether the feature is activated or not.B11 MR1 ED2

Counter ref name Long Name DefinitionMeasured objectDomainP390aNB_BSS_CS_PAGING_REQ_GPUNumber of CS paging requests coming from the BSC received by the GPU.Whenever a PAGING COORDINATION REQUEST message isreceived from the BSC the counter is incremented bynumber of CS Paging IEs contained within the message.GPU (Sub_BSS, BSC/FABRIC)Traffic loadP390b NB_CS_PAGING_REQ_PACCHNumber of CS Paging messages sent on PACCH.Whenever a CS Paging message is sent on (DL) PACCH the counter is incremented.CellTraffic load


Feature AssessmentMonitoring methods Statistical Tests Details and Expected results (3/6)3. Feature Specific Indicators check (contd): New Indicators starting B11 MR1 ED2:

Notes:The 1st & 3rd more meaningful when aggregated on the BSC level, because in case of multi-GPU BSC the GPU that receives that CS paging coordination request is not necessarily the one that processes this request and handles it by sending the CS paging request on the PACCH to the MS.The 3rd indicator is considered as the benefit brought by the feature to the end user, meaning that how many (or percentage of) the CS paging requests that would have been lost if the feature is not active.The next slide shows how we can estimate the number of CS paging Coordinationmessages sent on GSL through other counters (before B11 MR1 ED2), we may use 3estimation indicators:

NPO indicator refname LongName NPO Formula NPO B11DescriptionGCPGRQGNCS_Paging_Request_receivedP390aNumber of CS paging requests coming from the BSC received by the GPU.GCPGMPACNCS_Paging_Sent_MS_PACCH_PTMP390bNumber of CS Paging messages sent on PACCH.GCPGMPACRCS_Paging_Sent_MS_PACCH_PTM_rateP390b/P390aRate of CS Paging messages sent on PACCH.



The 1st estimation indicator:The 2nd estimation indicator: MC940. Because when feature is activated, any CS paging message received by the BSC from MSC (on A-interface) will be forward to the MFS (on GSL) through PAGING COORDINATION REQUEST message.The 3rd estimation indicator: MAX (GPRS_CS_Paging_Request (GTRPCHCSN) = MC8a - P53a - P53c)

DTM MSBTSBSCCellMSGPUMFSTCMSCSGSNAbis AterMUX-PSAterMUX-CSGbACS Paging request Message sent on PACCH in PTMCS Paging in PTMCS Paging MessagePS Paging message CS/PS Paging requests for MS on PCH MC925g P391aNumber of PAGING COMMAND received by the BTS on Abis and had to be sent for CS and PS traffic to the MS.Number of PS paging requests processed by the GPU.PAGING_COORDINATION_REQ IEs P390b (B11 MR1 ED2) P390a (B11 MR1 ED2)MC940Paging message received by the BSC from any MSC (on A interface).MAX (MC925g) - MAX (P391a)Among all cells managedby the BSCAmong GPUs of a BSCAmong cells of a BSCChannel assignment downlink message on PCH MC8a P53cPaging commandmessage (CS+PS Paging)PS Paging Messages on PCH P53aCMCC FO Results


Feature AssessmentMonitoring methods Statistical Tests Details and Expected results (5/6)3. Feature Specific Indicators check (contd):Expected Results:Pre- B11 MR1 ED2: to conclude the indicator to be used as an approximation (estimation) of the GSL paging Coordination requests sent from BSC to MFS.B11 MR1 ED2 and up: to ensure that the new indicators/counters (P390a & P390b) have consistent values with the activation of the CS paging coordination and to assess the gain brought by the feature: CS_Paging_Sent_MS_PACCH_PTM_rate (%).


Feature AssessmentMonitoring methods Statistical Tests Details and Expected results (6/6)4. GSL load monitoring after feature (BSCMFS direction):Every CS paging received by the BSC on A-interface will be forwarded to the MFS, that is why the GSL load in BSC MFS direction will increase.Indicators & counters mentioned in ANNEX G should be checked:

Expected Results:GSL Load study: make use of GSL counters & CS paging coordination indicators (before / after feature activation to be able to indentify / assess the increase in GSL load).Check if re-dimensioning of the GSL is needed after introducing the feature.GSL Load Monitoring


Field Trials


Feature AssessmentField Trials

The feature was assessed in:CMCC B11 MR1 ED1.0 FO (Xian city Pilot, China)

B11 MR1 ED1.0 On-air Platform (Velizy, France)


CMCC B11 MR1 ED1.0 FO Tests Results


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Highlights (1/2)Tests Performed in CMCC B11 MR1 ED1.0 FO (Xian Pilot):1. Unitary CS Performance tests: non-DTM case only.In CMCC network, DTM feature is not activated and therefore the feature interest for Full Support DTM of the DTM (second feature interest) could not be validated through CS Performance unitary (second category of unitary tests).2. PS non-regression unitary tests.3. Statistical tests:a. CS & PS QoS Follow-up, stability and availability Follow-up.b. Specific indicators Check: the new counters (P390a/b) could not be validated in CMCC FO because they are only available in B11 MR1 ED2, estimation indicators were used.c. GSL Load Study: could not performed (see next slides).Test procedure is the same as described in monitoring methods section.Tools:Nemo Tool Chain (Outdoor + Analyze).Nokia N95 Trace MS + 1 MS used for calling the trace MS.Wireshark traces were captured.NPO4U (NPO31_D23) tool was used for statistical tests.


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Highlights (2/2)Pilot BSC Parameter Settings:EN_RA_CAP_UPDATE = TRUENetwork Mode of Operation (NMO) = 2Test Cells Parameter Settings:EN_FAST_INITIAL_GPRS_ACCESS = FALSEMAX_GPRS_CS = 4 & MAX_EGPRS_MCS = 9TBF_xL_INI_MCS = 5 & TBF_xL_INI_CS = 2Round_trip_delay < 500 msec (not satellite Abis/Ater)Note: Paging Repetition is not enabled in Huawei MSC managing the Pilot BSCRadio Conditions:The tests were performed at cell (suburban environment) TMP_XAD703_0 (CI = 17034, BCCH = 529, BSIC = 70) in good radio conditions: Average RxLev = -53 dBm to -56 dBm.Average Mean BEP = 30.7 to 31.Average CV BEP = 6.9 to 7.All the tests are static.


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (1/10)

When the feature is not activated, all the CS terminating calls are lost except for PING sessions with relatively long pauses where CS paging can be received on the CCCH (PCH) channels (this observation is further described in the next slides). When the feature is activated, all terminating CS calls are received (100% success) during different PS sessions except for Ping Sessions with long pause durations where the CS calls success rate is around 90 92% (this issue is further described next)


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (2/10)The MS knows that the cell is supporting the CS paging coordination feature (i.e. it is expecting to receive CS paging on PACCH) by the BSS_PAGING_COORDINATION Flag which present in SI13 & Packet Assignment messages (L3 messages) sent from the network to the MS, as seen in the below snapshot:


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (3/10)Snapshots from NEMO Analyze for the observed behavior when MS is performing a PING (2 sec pause) PS session which is interrupted by an incoming CS call (1):


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (4/10)Ping session is interrupted by receiving CS paging on PACCH, leading to the de-allocation of the PS timeslots, MS leaves PTM to PIM, CS call setup is ongoing (2):


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (5/10)CS call is released, GPRS is resumed, Ping Session continues (3):


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (6/10)Notes:In case of PING sessions with long Pause durations, the CS paging can be received either on PCH or PACCH, this is mainly because in this kind of PS sessions, the MS leaves Packet Transfer Mode (PTM) and enter Packet Idle Mode (PIM) for a certain duration (according to the Pause values) and accordingly:If the network pages the MS while it is in PTM, the CS paging message will be received on PACCH (because the feature is activated).If the network pages the MS while it is in PIM, the CS paging message will be received on PCH.As you can see below in Ping tests with 5 sec pause around one-third 1/3 of the random CS paging requests are received on PCH:


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (7/10)Notes:When the CS paging is received (on PACCH or PCH), the on-going (E)GPRS session is suspended until the CS calls ends.However, in case of performing a long CS call the application may be dropped after finishing the call, but this is not an issue as it completely depends on the time-out of the application (application dependant).For example: In UL/DL FTP sessions performed in CMCC FO, the default FTP Time-Out is 30 sec, it was noticed that in case of short calls (< 30 sec), the FTP UL/DL will continue after the call is released; however in case of Long calls (> 30 sec), the FTP UL/DL will be dropped as shown in the next diagram:


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (8/10)Notes:Degradation of RTT & Ping success rate (for Ping Test) and average throughput (for UL/DL FTP tests) is noticed during the tests when CS paging messages is received (either on PACCH or PCH) while a PS session is on-going:This is normal, since the main purpose of the feature is to ensure that MS can receive paging even it is in PTM.In the next diagram, we notice degradations in the Ping session performance:Some Pings are unsuccessful when CS calls are received.Degradation of the Ping RTT when CS calls are received compared to the nominal RTT values (no interruption by CS calls).


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (8/10)


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (9/10)Observation:When the feature is not activated and in case the MS is performing Ping Session with relatively long duration (3 sec, 4 sec ), there is a chance of catching some terminating CS calls.These sessions are characterized by alternating PTM PIM changes. Therefore if the CS paging message (on the CCCH i.e. PCH) is sent by the network while MS is in PIM, the CS call will be established and the (E)GPRS session will be suspended.The whole scenario of such cases is shown in: ANNEX H


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS Performance Tests (10/10)Issue: 3BKA20FAG287622 [CLOSED]Problem Description:Sometimes during a Ping session with 1460B or 32B (101 iterations) with relatively long pause between iterations, the CS paging is not received (i.e. the MS is not reachable) although the CS paging Coordination feature is activated.The issue does not appear for Ping sessions with short pause durations (0, 1 sec) and UL/DL FTP sessions.Problem details:PS sessions characterized by changes of MS states PTMPIM (during session) suffer from this problem. Namely, Ping Sessions with 3, 4, 5, sec pause between iterations.The most the severe one observed being Ping sessions with 5 sec pause where quick PIM PTM changes occur.As the pause duration increases, the MS stays more in PIM and there is a less probability of losing CS paging.Problem History & DetailsConclusion


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Non-regression Data Performance Tests (1/2)DL and UL FTP transfer PS sessions:


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Non-regression Data Performance Tests (2/2)Ping 32B, 1460B with 0 and 5 sec pause between iterations PS sessions:

The non-regressions Data Performance Tests results are quite similar before / after feature activation This large difference is not linked to the feature but it linked to an issue with Nokia N95 MS, where high variance in the RTT values are encountered for large Ping Size with long pause durations. CS paging coordination feature shows non-regression in PS data performance tests


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS and PS QoS Follow-up (1/12)QoS non-regression for the main CS indicators:



Due to Peak negative (wrong) stagnating value for exe fail BSS on 15/10 from 1h till16h on 1 cell (CI=15854)Due to Peak drop of E2E CSSR on 20/10 @ 04h and on 22/10 @1h on 1 cell (CI = 14586)



Almost stable SDCCH and TCH traffic (around 1.5% increase only)



Almost stable Paging of PCH (around 1.3% decrease only) CS QOS Indicators are stable after feature activation


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS and PS QoS Follow-up (5/12)QoS non-regression for the main PS indicators:





See Next Slides95.23% increase111.17% increase2.13% decrease5.37% decrease





GPRS Traffic has increased by 10.4% and EGPRS by 0.8% PS QOS Indicators are stable after feature activation


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS and PS QoS Follow-up (10/12)An increase in the DL acceptable release due to Suspend is noticed after feature activation (around 95.23% increase than in the reference period)


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS and PS QoS Follow-up (11/12)An increase in the UL acceptable release due to Suspend is noticed after feature activation (around 111.17% increase than in the reference period)


Feature AssessmentCMCC B11 MR1 ED1.0 FO results CS and PS QoS Follow-up (12/12)The increase in the acceptable release due to suspend cause is normal after feature activation; since with the new feature, on-going GPRS sessions are suspended to serve the incoming CS calls.In other words, we can indentify the gain of the feature by the increase of this indicator; meaning that the increase in the acceptable release due to suspend cause may give an idea of the number of CS calls that could have been lost if the feature is not activated.We notice that GPRS_xL_TBF_acceptable_release_rate did not increase because of the decrease of other acceptable release causes (namely NCO reselect & radio pre-emption release); therefore the overall acceptable release rate did not really increase after feature activation.GPRS_DL_connection_time_avg and GPRS_UL_connection_time_avg has a little bit decreased (around 2.13% & 5.37% decrease). This is also normal because after feature activation there are a higher chance to interrupt the on-going DL/UL sessions by the incoming CS calls.Note: DL PACCH Load did not increase due to the new CS PAGING PACCH messages after feature activation:


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Availability and Stability Follow-up (1/5)Availability

Feature Activation


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Availability and Stability Follow-up (2/5) Total alarm occurrences:

BSC/BTS/Cell AlarmsMFS AlarmsFeature ActivationTotal_Alarms_Count = 183Total_Alarms_Raised_Count = 487Total_Alarms_Count = 161Total_Alarms_Raised_Count = 347Feature ActivationTotal_Alarms_Count = 59Total_Alarms_Raised_Count = 91Total_Alarms_Count = 43Total_Alarms_Raised_Count = 27W942W943W942W943


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Availability and Stability Follow-up (3/5)BSC Alarms:Feature Activation


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Availability and Stability Follow-up (4/5)BTS Alarms:Due to a problem on BTS_xasesn007/2/16 on the 19th and 20th of October (fixed after that)Feature Activation


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Availability and Stability Follow-up (5/5)Cell QoS alarms:

Conclusion:Feature ActivationCELL2G_QoS_Alarms_Count = 54W942W943CELL2G_QoS_Alarms_Count = 54No regressions were observed in either availablity or stability after activating the CS paging coordination feature.


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Paging Coordination Requests Estimation (1/2)The BSS version in CMCC FO was B11 MR1 ED1.0, P390a/b counters are not available.Accordingly, in CMCC B11 FO we could use estimation indicators previously described to estimate the number of CS paging IEs in PAGING COORDINATION requests sent on GSL:The 3 indicators can be an overestimated value for the number of the PAGING COORDINATION REQUEST IEs received from the BSC, because in case of MxBSC, if Multiple Paging on Abis is enabled and several Paging messages for same IMSI are buffered, a single Paging Request is only sent on the GSL.The next slide shows these 3 estimation indicators computed for the pilot BSC:

Estimation Indicators


Feature AssessmentCMCC B11 MR1 ED1.0 FO results Paging Coordination Requests Estimation (2/2)

The 2nd & 3rd indicators have stable and similar values which are inline with the working days and weekend traffic distribution.1st indicator has a lot of peaks (sometimes equal to 2nd & 3rd, sometimes equal to their double values!). Also its values are not inline with weekly traffic distribution.Conclusion: if the new counters (P390a & P390b) are not available, it is better to use MC940 for estimating the number of PAGING COORDINATION REQUEST IEs received from the BSC.Feature ActivationWeekendWeekend


Feature AssessmentCMCC B11 MR1 ED1.0 FO results GSL Load Monitoring in CMCC FO (1/2)Normally, GSL counters should be used to monitor the GSL load after feature activation because of the increased additional load coming from Paging Coordination Request messages sent from the BSC MFS (as described in the monitoring section).The PM counters related to GSL exist in Type 7, Type 110 BSC counters and GPMRES PM MFS counters.However in CMCC B11 FO, all these GSL PM counters had no values during the reference and the feature follow-up periods as detailed in:Because of these issues the GSL Erlang can not be calculated as per last dimensioning report done during CMCC FO:

(*) There are no GSL counters (P41 and P42) for during the observed period. GSL Erlang can not be computed (?).ANNEX H

ResourceNeededCurrentStatusAter Mux PS2020OKGSL?16*GP33OKAter Mux CS1922OKN7416OK


Feature AssessmentCMCC B11 MR1 ED1.0 FO results GSL Load Monitoring in CMCC FO (2/2)An alternative way to dimension the number of needed GSL link based on number of GSL messages per second sent from MFS to BSC is described in Architecture and Dimensioning B9 guidelines.However this method can not be used to estimate the increased load after feature activation because we are interested in the opposite direction i.e. CS Paging Coordination Request message from BSC to MFS.

Conclusion:Unfortunately, calculation (or estimation) of the GSL load increase after CS paging coordination feature activation in CMCC B11 MR1.0 FO has failed due to the issues discussed before!


B11 MR1 ED1.0 On-air Platform Tests Results


Feature AssessmentB11 MR1 On-air platform results HighlightsTests Performed Summary in B11 MR1 ED1.0 On-air Platform (Velizy): 1. Unitary CS Performance tests: for both DTM and non-DTM cases.2. PS non-regressions tests.Test procedure is the same as described in monitoring methods section.Tools:NEMO Tool Chain (Outdoor + Analyze).Nokia N95 trace MS (MS performing PS sessions).Agilent NITRO with Sagem OT290 trace MS (MS performing CS calls to N95 MS).Wireshark traces were captured.K15 Traces on RSL/RLC-MAC (Abis), GSL and A were captured during tests.Radio Conditions: DL RxLev = -55 dBm to -60 dBm & Mean_BEP = 31.Parameter Settings:EN_RA_CAP_UPDATE = TRUE, Network Mode of Operation (NMO) = 2EN_FAST_INITIAL_GPRS_ACCESS = FALSEMAX_GPRS_CS = 4 & MAX_EGPRS_MCS = 9TBF_xL_INI_MCS = 6 & TBF_xL_INI_CS = 2Round_trip_delay < 500 msec (not satellite Abis/Ater)Note: Paging Repetition is enabled in the simulated core (LSU) managing the BSC.


Tests Results:

Notes about Tests Results: - Same results and observations as CMCC B11 MR1 ED1.0 FO:Call Completion success rate is 100% when the feature is activated during the different PS sessions in EDGE and GPRS modes.When the feature is deactivated all the CS terminating calls are lost (Call Completion success rate is 0%) except for PING session with relatively long pause durations. - The issue of losing some CS paging during Ping Sessions with relatively long durations was not noticed in on-air platform tests. Most probably because Paging Repetition is Enabled in core (LSU), which decreases the risk of this issue (as previously described). Feature AssessmentB11 MR1 On-air platform Results - CS performance tests without DTM feature

CS Paging Coordination DISABLEDCS Paging Coordination ENABLEDPS Session TypeNumber of Terminating CS CallsCall Completion Success (Rate%)Number of Terminating CS CallsCall Completion Success (Rate%)CS Calls During DL FTP PS Session130 (0%)1313 (100%)CS Calls During DL FTP PS Session (GPRS Mode)1616 (100%)CS Calls During UL FTP PS Session130 (0%)1313 (100%)CS Calls During PING "Pause 0s" PS Session110 (0%)1111 (100%)CS Calls During PING "Pause 1s" PS Session100 (0%)1010 (100%)CS Calls During PING "Pause 5s" PS Session175 (29.4%)1712 (100%)


Test Results

Notes about Tests Results:- DTM Call Completion success rate is 100% when the feature is activated during the different PS sessions.- When the feature is deactivated all the DTM calls were not completed (DTM Call Completion success rate is 0%) except for PING session with 2 sec pause, because of the same reason mentioned before.- The same scenario happens (like without DTM) when the feature is deactivated, Call Disconnect is sent to the Calling MS with cause 18 No user responding.

Feature AssessmentB11 MR1 On-air platform Results - CS performance tests with DTM feature (1/6)

CS Paging Coordination DISABLED DTM is ENABLEDCS Paging Coordination ENABLED DTM is ENABLEDPS Session TypeNumber of DTM Calls (incoming CS Calls)DTM Call Completion Success (Rate%)Number of DTM Calls (incoming CS Calls)DTM Call Completion Success (Rate%)CS Calls During DL FTP PS Session110 (0%)1010 (100%)CS Calls During UL FTP PS Session100 (0%)1414 (100%)CS Calls During PING "Pause 0s" PS Session44 (0%)77 (100%)CS Calls During PING "Pause 2s" PS Session132 (15.38%)


DTM call establishment main procedures overview (FTP UL and CS call):MS is in PTM mode (performing an UL FTP Transfer).CS paging on PACCH (feature activated), MS leaves PTM, CS call is being established (dedicated mode).CS call is established, MS is transferred to DTM mode (performing an UL FTP transfer and CS call simultaneously).CS is Released, MS is in PIM then back to PTM.

Feature AssessmentB11 MR1 On-air platform Results - CS performance tests with DTM feature (2/6)


Main procedure snapshots when feature is activated and DTM activated (FTP UL Transfer Session and CS call) (1):Feature AssessmentB11 MR1 On-air platform Results - CS performance tests with DTM feature (3/6)


Main procedure snapshots when feature is activated and DTM activated (FTP UL Transfer Session and CS call) (2):Feature AssessmentB11 MR1 On-air platform Results - CS performance tests with DTM feature (4/6)


Main procedure snapshots when feature is activated, DTM activated and FTP UL Transfer Session (3):Feature AssessmentB11 MR1 On-air platform Results - CS performance tests with DTM feature (5/6)


Main procedure snapshots when feature is activated, DTM activated and FTP UL Transfer Session (4):Feature AssessmentB11 MR1 On-air platform Results - CS performance tests with DTM feature (6/6)


Test Results:

- From the above results, we observe no regressions in terms of FTP throughput, Ping success rate and RTT.

Feature AssessmentB11 MR1 On-air platform Results - PS Non-regressions Tests Results

CS Paging Coordination DISABLEDCS Paging Coordination ENABLEDPS Session TypeAverage Application Throughput (Kbits/sec)PING Success Rate %Average RTT (ms)Average Application Throughput (Kbits/sec)PING Success Rate%Average RTT (ms)2 x DL FTP PS Session259.63259.702 x UL FTP PS Session153.35153.121001 PING 32B "Pause 0s" PS Session100%192.67100%192.75


Conclusion4


Conclusion (1/2)CS Paging Coordination FO Results:Unitary Tests Results:When the feature is activated, all terminating CS calls performed towards an MS currently engaged in a PS session are well received (100% success) except for Ping PS session with relatively long duration (3, 4, 5 .) seconds between iterations where around 90 94% success is experienced.After analysis done by TD for this issue, the conclusion is that ALU BSS B11 SW is compliant to 3GPP specs where no means to avoid losing some CS paging requests in all situations is described, the explanation for the reason of this problem is to be provided to the customer, no change is needed in ALU B11 BSS SW.This issue will probably occur more in networks having Paging Repetition not enabled in the Core Network (ex: this issue was not encountered during Velizy on-air platform feature tests because paging repetition was enabled in simulated core (LSU).No regression in data performance PS tests after feature activation.Statistical Tests Results:No regression in CS and PS main KPIs after feature activation.No regression of availability & stability of the BSC/BTSs/Cells after feature activation


Conclusion (2/2)

Statistical Tests Results Contd:Increase of DL/UL acceptable release due to suspend cause after feature activation which is normal because there is higher probability of interrupting the on-going PS session by incoming CS calls.If the new counters (P390a & P390b) are not available, it is better to use MC940 counter for estimating the number of PAGING COORDINATION REQUEST IEs received from the BSC.GSL Load increase study after feature activation:Unfortunately, it was not accomplished due to the issues will all PM GSL counters in CMCC B11 MR1.0 FO and the unavailability of the new feature counters (P390a/b).Support of CS paging Coordination in BSS feature is recommended to be activated in networks hoping for an increase of CS Paging Performance and/or full DTM feature support without implementing Gs-interface in core network while ensuring no degradation in end-user data performance, CS & PS QoS KPIs and network stability & availability as seen in CMCC B11 MR1 ED1.0 FO.However, GSL load/dimensioning should still be monitored/assessed after feature activation as no quantification of its expected increase could be accomplished during FO.It is worth mentioning that DTM still needs FMA to be open for Commercial use.


www.alcatel-lucent.comwww.alcatel-lucent.com


ANNEX5


The 3GPP standard has defined three network operation modes for paging coordination between CS and PS:Network operation mode I: The network sends a CS paging message for a GPRS-attached MS, either on the same channel as the CS paging channel (PCH) or on a GPRS traffic channel (PACCH). The MS needs only to monitor one paging channel. It receives CS paging messages on the packet data channel when it has been assigned a packet data channel. Gs interface is needed between the MSC and SGSN for to carry the CS paging to SGSNno CS paging is lost.

Annex ANetwork Mode of Operation & MS Classes (1/4)


Network operation mode II: The network sends a CS paging message for a GPRS-attached MS on the CCCH paging channel, and this channel is also used for GPRS paging.The MS needs only to monitor the CCCH paging channel.CS paging continues on CCCH paging channel even if the MS has been assigned a packet data channel. CS paging messages received while the MS is in packet transfer mode are lost.Network operation mode III (in case of MPDCH): The network sends a CS paging message for a GPRS-attached MS on the CCCH paging channel, and sends a GPRS paging message on either the packet paging channel (PPCH) (if allocated in the cell) or on the CCCH paging channel. A MS that wants to receive paging messages for both circuit-switched and packet-switched services shall monitor both paging channels in the cell, if the packet-paging channel is allocated.The network performs no paging coordination.CS paging messages received while the MS is in packet transfer mode are lost.Annex ANetwork Mode of Operation & MS Classes (2/4)


The below table shows the paging coordination (CS & PS) and the radio channels used in the different network modes of operation till B10:

Note that BSS paging coordination is not taken into consideration in this table. Annex ANetwork Mode of Operation & MS Classes (3/4)


GPRS MS Modes of Operation:Class A:The MS is attached to both GPRS and GSM. MS supports simultaneous attach, simultaneous activation, simultaneous monitor and simultaneous traffic. The mobile user can make and/or receive calls/sessions on the two services simultaneously. Needs 2 independent transmitter/receiver.Class B:The MS is attached to both GPRS and GSM, but the MS can only operate one set of services at a time. When the MS is in both idle mode and packet idle mode it should be able to monitor paging channels for both circuit-switched and packet-switched services depending on the mode of network operation and the implementation of the CS paging coordination in the BSS. Class C:The UE is attached to either GPRS or other services. Alternate use only.Annex ANetwork Mode of Operation & MS Classes (4/4)BACK


Idle Mode:The mobile is in idle mode when not engaged in a connection for either PS or CS.Dedicated Mode:The MS is in dedicated mode when a SDCCH or a TCH has been established for a CS call. Packet Transfer Mode:The mobile is in packet transfer mode (PTM) when a PS transaction is established. Contrarily to dedicated mode, the packet transfer mode allows multiplexing several MS on one or several radio channels.Dual transfer mode (DTM):Combination of packet transfer mode and dedicated mode. ANNEX BB10 Dual Transfer Mode (DTM) (1/6)


Description:Allows establishing simultaneously within one single GSM mobile station a packet transaction and a circuit switched call, without the need for class A mobiles.Example: sending a photo during a voice call, or browsing through emails while talking with another person.Since simultaneous CS/PS traffic capability is natively offered by UMTS, the DTM feature is particularly interesting for 2G Operators being in competition with 3G operators, or for 2G/3G Operators for 3G services continuity purpose in areas where 3G services are not offered.DTM feature is an optional feature since B10.The DTM feature is introduced by 3GPP:Feature part of Release 99 specifications with improvements in Release 4, 6 and 7.B10 implementation is aligned with Release 4 definition of the feature.Has impact on BSS, MS software and some Core Network dependencies.ANNEX BB10 Dual Transfer Mode (DTM) (2/6)


ANNEX BB10 Dual Transfer Mode (DTM) (3/6)Mode Transitions for DTM capable MSs in 3GPP R4Direct transition from PTM to DTM not possibleFirst release the TBFsEstablish CSThen re-establish TBFs in DTMDirect transition from DTM to PTM not possibleFirst release TCH and PDCHsThen re-establish the TBFs in PTMDirect transition from Idle mode to DTM not possible: Dedicated mode is a mandatory phaseTransition from DTM to dedicated mode is possible


Class A DTM Modes of Operation:Like a class A mobile, but without the need of a dual transmitter/receiver.

ANNEX BB10 Dual Transfer Mode (DTM) (4/6)Scenario 1: Entering the DTM mode for a MS already in Packet Transfer Mode and receiving a CS call request.Scenario 2: Releasing the CS connection in DTM.Scenario 3: Releasing the PS connection in DTM, then releasing the CS connection.


Supported radio configurations :DTM Multislot class 5:1 TCH + 1 DL PDCH and 1 UL PDCHDTM Multislot class 9:1 TCH + up to 2 DL PDCH and 1 UL PDCHDTM Multislot class 11:1 TCH + up to 2 DL PDCH and 1 UL PDCH1 TCH + 1 DL PDCH and up to 2 UL PDCH (*)DTM Multislot class 31:1 TCH + up to 3 PDCH DL and 1 UL PDCH.DTM Multislot classes 32, 33:1 TCH + up to 3 PDCH DL and 1 UL PDCH.1 TCH + up to 2 PDCH DL and 2 PDCH UL (*)(*) These configurations require the activation of the EDA B10 feature.ANNEX BB10 Dual Transfer Mode (DTM) (5/6)


DTM requirements:Only supported by Evolium BTSs.

Only supported in non-extended cells (to simplify implementation).

The MAX_PDCH_HIGH_LOAD 2, at least 2 TS are needed for DTM resource allocation. The DTM resources will be allocated inside the non-preemptable zone.

No guarantee by ALU of DTM correct behavior when CS paging coordination is absent:Either through Gs interface (NMO I) CS paging through SGSN or By activating the B11 feature Support of CS paging coordination in the BSS (NMOII).This is to avoid loss of CS paging requests while the MS is in Packet Transfer Mode Support of CS paging coordination is highly recommended with DTM feature.ANNEX BB10 Dual Transfer Mode (DTM) (6/6)BACK


The new PAGING COORINATION REQUEST message sent from the BSC to the MFS has the following content:

The CS Paging IE Information element is defined as follows:

TMSI and eMLPP Priority fields are optional (their length could be ZERO)Annex CFormat of PAGING COORDIANTION REQ messageBACK


The assumption that the SGSN always provides for MS in PTM mode the most accurate cell is true of ALU SGSN but maybe false for other SGSN vendors.The strategy used in CS Paging coordination in the BSS can be also used in SGSN to remove the risk of the Assumed SGSN behavior.The idea is to take profit of IMSI vs MS Context relationships to use a similar algorithm to manage the Paging Coordination for both cases (in SGSN/in BSS).When MFS receives a GMM-PAGING-CS message the MFS shall:1. Browse through the set of IMSI vs MS Context relationships to find the corresponding IMSI;2. If IMSI is found (i.e. MS is in PTM mode), MS Context is known and the CS Paging is sent on the corresponding PACCH;3. Otherwise (IMSI not found), MS is not in PTM mode, the CS Paging has to be sent on PCH (CS Paging is forwarded to the BSC through the GSL with the Paging Area provided by the SGSN).This option is linked to the use of Gs interface in the core network and not with the Support of paging coordination in the BSS B11 feature. Remark: This option has not been implemented yet in our B11 BSS release. This option (if implemented in future releases) has to be estimated separately including non-regression tests.ANNEX DCS paging coordination in SGSN Modification non B11 feature


Unitary Tests pre-requisites:At least 1 cell of one BSC:Not presenting any congestion issue: neither on air nor on transmission resources.Avoid satellite Abis/Ater cells (Round_trip_delay > 500 msec) feature not functional.Tests during the reference week EN_BSS_PAGING_COORDINATION = FALSETests during the feature observation week EN_BSS_PAGING_COORDINATION = TRUENEMO tool chain (Outdoor + Analyze), 1 trace MS (ex: Nokia N95) + SIM card.1 additional MS used for performing calls towards the trace MS + SIM card.(Optional) K15 traces on GSL, A and RSL & RLC-MAC (Abis). Dedicated server available for FTP transfers & Ping (APN, user name, password).The radio conditions during tests should be very good:At least DL RxLev >=-65dBm, RxQual = 0 and/or Mean_BEP between 27 and 31.Resources:1 RNE for Data Performance Tests and Post Processing.1 OMC-R Support for changing the parameters.(optional) TSC support for taking K15 traces.Reference and feature observations tests should be performed at the same hour and in the same location; busy hours of the selected should be avoided.ANNEX EMonitoring methods Tests Pre-requisites (1/2)


ANNEX EMonitoring methods Tests Pre-requisites (2/2)Statistical Tests pre-requisites:Reference and observation periods statistical Data for 1 BSC:Main CS & PS QoS KPIs, unavailability and stability indicators.Reference period minimum 1 week (EN_BSS_PAGING_COORDINATION = FALSE).Observation period minimum 1 week (EN_BSS_PAGING_COORDINATION = TRUE).Particular periods statistical data for cells were unitary tests took place.NPO & NPO LASER / NPO4U tool availability.Reference ACIE files (before &after feature activation, during Unitary tests) should be stored for parameters check.

BACK


ANNEX FMonitoring methods Unitary Expected results (1/2) CS Performance without DTM Tests Expected Results:When feature is Deactivated:All terminating CS calls will be lost (MS is unreachable) while MS is transferring data (uploading / downloading in UL/DL FTP tests).While MS is performing PING sessions, it is interesting to notice that some of the terminating CS calls may be possible (PCH Paging). As the Pause duration increases, the chance of catching the CS Paging on PCH is higher.When feature is Activated:All terminating CS calls performed towards the MS during any PS session should be received (i.e. 100% success rate). The PS session will be suspended till the CS call finishes. CS Performance with DTM Tests Expected Results:When feature is Deactivated:DTM calls will not be possible, CS paging will be lost while MS is transferring data (uploading / downloading in UL/DL FTP tests).However in PING sessions, some DTM calls may be possible (PCH Paging), as the Pause duration increases, chance of establishing DTM calls is higher.


ANNEX FMonitoring methods Unitary Expected results (2/2)CS Performance with DTM Tests Expected Results (Contd):When feature is Activated:DTM calls will be established (100% success rate), CS paging will be captured in any PS sessions.The PS session will be suspended till the CS call is established, afterwards CS and PS sessions will be simultaneously active (DTM).Non-regression PS Performance Tests Expected Results:For UL/DL FTP PS sessions:Non-regression in terms of UL/DL throughput.For PING session:Non-regression in terms of RTT and Ping Success Rate.

BACK


GSL load is the main issue of concern in ALU implemented strategy4 methods are used to reduce the extra BSCGP load (GSL load):1. Information sent to the MFS is reduced to the minimum only IMSI (no Paging area is provided).2. Filtering is performed by the BSC (no load of the GSL with useless CS paging requests).3. The MS context is NOT shared with the BSC, this is to save any extra MFS to BSC synchronization messages.Example for MFSBSC sync: if the MFS will inform the BSC that an MS has entered or leaved the PTM mode, on the other hand this will avoid conveying useless CS paging requests on the GSL for MS not in PTM mode (or even for non-GPRS attached MS).4. Multiple Paging commands is performed on the GSL in same way and in parallel with Multiple Paging command on Abis (managed by same set of parameters T_SEND_MULTIPLE_PAGING_CMD and NB_MAX_MSG_MULTIPLE_PAGING_CMD).Remark: Multiple Paging on GSL is NOT available for G2 BSC.Due to this extra BSCGP load needed to manage PAGING COORDINATION REQ messages, it may be necessary to manage a 3rd GSL per GPU.However there is a very low risk because normally the GSL load occur in the MFSBSC and not in the opposite direction BSCMFS; however it may be useful to assess / dimension the GSL load.ANNEX GGSL Load (1/3)


We can use the normal way in dimensioning the GSL load (as described in BSS Architecture Guidelines document) based on GSL Bandwidth:We can use the two MFS counters P41 and P42 (7-day Busy Hour data, recommended) after activating the featureP41: Number of kilobytes sent to the BSC on the LapD link.P42: Number of kilobytes received from the BSC on the LapD linkWe will use the following formulas to calculate the number of required GSLs:

We will check the GSL load using these 2 formulas, if the GSL load is higher than 80% the number of GSLs per GPU should be increased:

The assessment based on number GSL messages/sec is only done in the MFS BSC direction (being the more critical direction), the maximum number of GSL links from both methods will be used.

ANNEX GGSL Load (2/3)


New B11 indicators provided at GSL level (type 7) can be consulted to monitor the GSL load in the BSCMFS direction (UL):GSL_BSC_MFS_Message_Sent: Number of GSL messages sent by the BSC to the MFS on one GSL link.GSL_BSC_MFS_Sent_Bytes: Number of bytes sent to the MFS on 1 GSL link.GSL_BSC_MFS_Sent_Bytes_Max:Maximum number of bytes of the GSL flow sent by the BSC to a given GPU in one minute during the granularity period of monitoring.GSL_BSC_MFS_Message_Sent_Max: Maximum number of GSL messages sent by the BSC on a given GSL link to the MFS in one minute during the granularity period of monitoring.GSL_BSC_MFS_Message_Sent_Avg: Average number of GSL messages queued in the BSC transmission buffer of one GSL link (at Layer 2 level).GSL_MFS_BSC_BSCGP_Message_Received: Number of BSCGP messages received by the MFS from the BSC.GSL_LAPD_Congestion_Time: Time (s) during which the GSL LapD link is congested in transmission in the BSC.Starting B11 MR1 ED2, the new counter P390a (counting the number of Paging Coordination Request received by the GPU) can be used to get the number of CS paging coordination message / sec sent by the BSC on the GSL interface.For older B11 versions, the estimation indicator (= MC940) can be used as an approximate value; however this estimation indicator does not indicate that the feature is working (because it will have values before/after feature). Counter P42 & the above indicators can be consulted and compared after feature activation which should have higher values as long as we are comparing in steady traffic conditions.ANNEX GGSL Load (3/3)BACK


ANNEX HCS paging success when feature is not activated (1/3)Ping session (101 iter., 32B, Pause 5 sec) is on-going, many CS calls is continuously performed randomly, but there was no chance to catch the pause period (MS in PIM) i.e. CS paging is lost MS is unreachable (1):


ANNEX HCS paging success when feature is not activated (2/3)During the 5 sec pause duration (MS in PIM), a CS paging request is received on CCCH (PCH), leading to the suspension of the (E)GPRS session (2):


ANNEX HCS paging success when feature is not activated (3/3)After CS call is released, (E)GPRS Ping session is resumed (3):

BACK


ANNEX ILoss of CS calls during pings with relatively long pause between iterations (1/7) History of the issue and investigations performed:At first the issue was observed for both Ping Sessions with 32B & 1460B ping sizes and 5 sec pause between iterations.Issue being more severe in case of 1460B Pings than in case of 32B Pings.(CS paging success rate = 94.18% & 90.36% respectively).Tests were repeated on 2 different cells (in good radio conditions) to make sure that the issue is not depending on the chosen cell.Both NEMO Ping and DOS ping tests were tried, CS calls were lost in both Ping sessions i.e. not an application problem.High paging load problem was suspected and to check that, the tests were repeated with other Ping sessions (short pause durations) and FTP DL & UL, all calls were received terminating CS success rate = 100% i.e. not a high paging load problem.Normally the CS paging failure is associated with a Ping Success i.e. it is not related to the issue of big Ping size with long Pause duration (FR: 3BKA45FBR287330).


ANNEX ILoss of CS calls during pings with relatively long pause between iterations (2/7) More tests were carried out to check if the above issue also appeared for Ping sessions with other pause durations (3, 4, 7 and 10 sec). Below were the results we got:

From the previous table we can deduce that the issue appears for Ping sessions with relatively long pause durations between iterations (3, 4 ,5, 7, 10 sec).The common behavior among all the above Ping sessions is the change of MS states PTMPIM during the session, as the pause duration increases the MS stays more in PIM and there is a less probability of losing CS paging.For PS sessions that always stay in PTM (no PTM PIM changes) that CS paging success rate is 100%. These sessions are UL FTP, DL FTP, Ping with Pauses 0, 1 sec.NE has suggested the following hypothesis (next slide) that could be the cause of the problem:


ANNEX ILoss of CS calls during pings with relatively long pause between iterations (3/7)A. Ping sessions with relatively long pause duration are characterized by this behavior:TBF is established for the transfer (MS in PTM), MFS creates an IMSI vs MS Context entry because MS is PTM i.e. CS paging can be sent on PACCH. After that the Pause duration starts, dummy blocks are sent to extend time when the TBF is established, i.e. CS paging can still be sent on PACCH.Because the pause duration is long, the TBFs are released (no TSs allocated) and the mobile leaves PTM i.e. PIM, MFS deletes IMSI vs MS context entry because MS left PTM, CS paging will not be sent on PACCH but will only be sent on CCCH channels (PCH).The TBF is re-established for the next Ping transfer and so onB. Normally when the BSC receives a CS paging from the MSC:The BSC forwards this paging on the Abis to the BTSs for paging on PCH.Also BSC sends on the GSL to the MFS (CS paging coordination request), MFS checks if the MS is in PTM (has an existing IMSI vs MS context entry); if found it will forward this Paging on PACCH, if there is no IMSI vs MS context entry the MFS discards the request and does nothing.


ANNEX ILoss of CS calls during pings with relatively long pause between iterations (4/7)C. MS goes back to PTM when CS Paging starts while the MFS still believes it is PIM: Due to this quick change in the MS states PTM PIM back and forth, there may be a chance when the CS paging is received on PCH and the mobile has just left PIM and entered PTM.At this instant that MFS "believes" the MS is in idle mode while the MS is actually in PTM mode. Hence, the MFS discards the corresponding CS paging coordination request (for the MFS the MS is in idle mode, i.e. no corresponding IMSI vs MS context entry for this MS) and therefore the CS Paging is NOT sent on PACCH.Till this entry is created inside MFS, the time during which the MS can be paged is over. Therefore the CS paging message is lost (i.e. the MS is not reachable).This NE hypothesis was discussed and agreed with SYT and later it was proven to be the cause of the problem.Note: EN_EXTENDED_UL_TBF parameter also impacts the time the MS is in PTM, however issue also occurred with different settings EN_EXTENDED_UL = (I-EUTM is used) & (EUTM is used).Further analysis from SYT (and VAL) teams showed that the exact behavior of the problematic scenario is as follows:


ANNEX ILoss of CS calls during pings with relatively long pause between iterations (5/7)Problematic scenario in case of transition from packet idle mode to packet transfer mode:1) The MS has no traffic (packet idle mode from MFS point of view: the last delayed DL / extended UL phases are over if there was a previous ping done with the MS).2) A new ping is triggered MS sends (EGPRS Packet) Channel Request on RACH to establish an UL TBF3) The MFS sends back an Immediate Assignment to the MS.4) On reception, the MS passes in Packet Transfer Mode:Extract from TS 44.018 section 3.5.2.1.3.1: On receipt of an IMMEDIATE ASSIGNMENT message or, in case of a two-message assignment, a matching pair of IMMEDIATE ASSIGNMENT messages corresponding to one of its 3 last CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST messages, the mobile station stops T3146 (if running), stops sending CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST messages, and switches to the assigned PDCH.5) The MFS then begins to schedule USFs.6) The MS sends the TLLI in the first UL RLC PDU which will allow contention resolution, and will send the next UL RLC PDUs in sequence.7) At that stage, the MFS does not know yet the IMSI of the MS (and the previous entry in the IMSI table of the MFS was anyway removed for this MS, because the MS was in PIM in step 1)).8) Later, the MFS can know the IMSI either through the RA Cap. update procedure or a DL LLC PDU to be sent to the MS; Only when such events occur, link between TLLI and IMSI can be done at MFS side.


ANNEX ILoss of CS calls during pings with relatively long pause between iterations (6/7)

Problem occurs if there is a CS paging request arrives in the BSC between step 4) (when MS leaves to PTM) and step 8) (IMSI is known inside the MFS), this paging request will be lost because the MS is in PTM, but the MFS does not send any paging request on PACCH because it does not know the IMSI of the MS yet (the link between TLLI and IMSI is not feasible yet).Conclusion:From specification point of view, ALU BSS is compliant to 3GPP.3GPP does not provide the means to avoid losing some CS paging requests in all situations, in particular like the problematic scenario previously described (when a CS paging request arrives in the BSC between step 4) and step 8)).This explanation is to be provided to the customer, no change is needed in ALU BSS SW.


ANNEX ILoss of CS calls during pings with relatively long pause between iterations (7/7)Additional important notes:In case Paging Repetition is enabled at the core (MSC/VLR) side, there is a very very low risk to have such issue (loss of CS calls during pings with long pause durations): Because the risk of getting more than one collision in same MTC is very low in the field, that is to say: if the paging repetition at the core side is 1, it is very unlikely to receive the 2 CS paging messages while the MS is in the problematic phase (MS is in PTM and IMSI is not yet known at MFS side).As the paging repetition increases, this risk decreases even more.The problem was detected in CMCC FO because Paging repetition is not enabled in Huawei core.R&D VAL team tests showed that when Paging Repetition is enabled, all MTCs were received (100% success) during Ping sessions with relatively long pauses.The RA Capacity Update procedure (EN_RA_CAP_UPDATE) should be enabled to minimize a bit the losses of CS paging requests (which is triggered at completion of TBF UL establishment to speed-up the IMSI retrieval).BACK


ANNEX JGSL PM counters Issue in CMCC B11 MR1.0 FO

New B11 BSC counters 106x (type 110): The new B11 BSC GSL Counters (MC1060 -> MC1067) in type 110 are empty (FR: CUSA00FAG244164).New B11 BSC Counters L2.x (type 7): only 1 GSL is reported in the PMTAR T07 files (instead we should have 16 GSLs) making it impossible to monitor each GSL link.New MFS counters P7x: After B11 migration, the MFS counters P7a, P7b, P7c_1, P7c_2, P7d, P7e, P7f, P7g, P7h & P7i are always equal to zero (FR: CUSA00FAG244542). Old MFS counters: the MFS counters P41 and P42 are without values after B11 migration (not present in the MFS GPMRES PMTAR files) (FR: CUSA00FAG244162).Old MFS counters: P2a, P2b, P2c, P2d & P32: not present in the MFS GPRMES PMTAR files, same issue like P41 & P42 because the whole block for BSC_MFS LAPD is not reported in GPRMES files.BACK

Agenda Pages

This page allows for the listing of the sections within a presentation.

Divider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide template****************

**Divider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide template****Divider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide templateDivider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide template*******Divider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide templateDivider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide template**********************************Divider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide template********Divider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide template**Divider Section Break Pages

Title block set 28/32pt Trebuchet white, flush left with text box positioned at, Horizontal 1.87 and Vertical 2.87This slide is to be used to create Section Divider slides Please copy, paste and modify this slide to reflect your specific needs. It is not generated from a Master slide template***********

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

[Seminar5] CS Paging Coordination in the BSS

Documents

[Seminar5] Introduction

5 esp seminar5-revisionclass_june14

series 2000 paging terminals - AIR Inc 2000 Paging... · paging encoding formats, and page entry stations— allows commercial operators to provide service to a ... the paging terminal

[Seminar5] Synch Netw

Paging Drop

Lecture 5.1 Protocol architecture overvie · PDF fileRIL3: Radio Interface Layer 3 RSM: ... (parameter transmitted on BCCH; ... BSS 1 BSS 2 MS f1 MSC BSS 1 BSS 2 MS f1 MSC BSS 1 BSS

Panasonic Telephone Systems - Voicesonic€¦ · DPT Features 4-97 Type Description Paging — All Paging — External Paging — Group Paging through both the built-in speakers and

AP-SPS180 SIP Paging ServerSIP Paging Server AP-SPS180 SIP Paging ServerSIP Paging Server High-performance Next Generation SIP Paging Server Solution ... - FTP, Telnet, TFTP, DHCP

KalashSeeds | Homekalashseeds.co.in/tomato.pdf · Kalash - : (0?8Q) 288000 : à ñfàu AT.fà., : (028'?) : (BSS 731) (BSS 684) (BSS 908) (BSS 1006) : (30 : (BSS 731) 900 (BSS 684)

BSS Quarterly Report BSS Reports

Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging

Paging Example

Paging - Cisco...Paging •PagingOverview,onpage1 •PagingPrerequisites,onpage2 •CiscoUnifiedCommunicationsManagerConfigurationforBasicPagingTaskFlow,onpage3

11 GSM BSS Network KPI (Paging Success Rate) Optimization Manual

Demand Paging

Operating Systems ECE344 Ding Yuan Paging Lecture 8: Paging

Paging Old2006

Content Paging

Paging - cisco.com€¦ · Paging •PagingOverview,onpage1 •PagingPrerequisites,onpage2 •CiscoUnifiedCommunicationsManagerConfigurationforBasicPagingTaskFlow,onpage3

OData Paging using SSIS – REST API Paging Example