Gsm Kpi Improvement

GSM KPI Improvement Process / Guidelines Key Performance Indicators – KPIs SDCCH Blocking SDCCH Drop TCH Drop Rate Handover Success Rate Limited Internal 2 NPI Training – Retainability 2005-09-30 Accessibility Definition Call to an MS MSC/VLR 1 TRC 1 BSC 5 3 2 1. MSC/VLR sends paging command to all BSCs belonging to the location area (LA) where MS is located 2. BSC forwards the paging command to all BTSs in that LA, and the BTSs in their turn page the MS on the PCH 3. The MS responds to the BTS on the RACH and the BTS forwards the response to the BSC (forward to MSC) 2 Accessibility 4 4. The BSCs checks with the BTS if it has an SDCCH available and the BTS grants the MS an SDCCH by using the AGCH 5. The MS and the BTS signal on the SDCCH, measurement reports sent on SACCH are forwarded from the BTS to the BSC and once the signalling is done the BSC decides which TCH to use 6. TCH connection established between MS and BTS BTS BTS 3 2 4 6 5 Limited Internal 3 NPI Training – Retainability 2005-09-30 SDCCH Congestion – Overview SDCCH Activities: ? Mobility Management – Normal Location update – Periodic Registration – IMSI Attach / Detach ? Connection Management – – – Call setup SMS Point to Point Fax Setup Supplementary Services Limited Internal 4 NPI Training – Retainability 2005-09-30 SDCCH Congestion – Overview Channel Configuration: ? Channel Configuration can be done as follow – Combined BCCH/SDCCH on 1 TS (SDCCH/4) – Non-Combined BCCH and SDCCH on 2 TS (SDCCH/8) ? Cell Broadcast Channel (CBCH) – – The Cell Broadcast service provides the transmission of an SMS from a message-handling centre to all MSs in the serving area of the BTS. If the Cell Broadcast service is active in a cell, one signaling sub-channel is replaced by one CBCH resulting in a SDCCH/7

Limited Internal 5 NPI Training – Retainability 2005-09-30 SDCCH Congestion – Overview SDCCH Channel Allocation Profile (CHAP) ? ? ? Channel Allocation is the feature that selects and allocates suitable channels when one or more channels are required Channel Allocation Profile (CHAP) is the parameter that provides different channel allocation strategies For SDCCH assignments, CHAP 8 prioritize new assignments as follows: 1. OL/SDCCH 2. UL/SDCCH (if OL/SDCCH is congested) Limited Internal 6 NPI Training – Retainability 2005-09-30 SDCCH Congestion – Overview A new assignment will use the SDCCH in OL first

B S T T T T P P T S T T T T T T T T T T T T T T T T T T T T T T OL (CHGR 0) B S T P BCCH timeslot SDCCH timeslot TCH timeslot PDCH timeslot UL (CHGR 1) If the OL is congested, the SDCCH in UL will be used B S T T T T P P T S T T T T T T T T T T T T T T T T T T T T T T OL (CHGR 0) UL (CHGR 1) Note SDCCH congestion in the OL will increment, but this is not customer perceived since the SDCCH in UL will then be utilized Limited Internal 7 NPI Training – Retainability 2005-09-30 SDCCH Dimensioning Strategy GOS Approach: ? SDCCH should be dimensioned for better GOS compare to TCH.

Typical range is 0. 5% – 1%. ? Immediate Assignment of TCH with “TCH as last option strategy” is recommended. ? It is recommended to add SDCCH when 0. 5 Erlang of signaling traffic is carried by TCH. ? Half Rate penetration, usage of Extended Range cell and HSCSD should be taken into consideration. STS Approach: ? Accurate dimensioning is achieved by using STS cell statistics Limited Internal 8 NPI Training – Retainability 2005-09-30 SDCCH Congestion Optimization Analyze the following issues that could be possible reasons for SDCCH Congestion: ? SDCCH Dimensioning ?

Incorrect use of SDCCH capacity features such as Adaptive Configuration of Logical channels ? TCH Congestion ? Location Areas not optimized ? SMS usage and Cell Broadcast channel ? SDCCH Availability Limited Internal 9 NPI Training – Retainability 2005-09-30 SDCCH Congestion Optimization The following recommendations will have a positive impact on SDCCH congestion ? ? ? ? ? ? Try not to use combined BCCH/SDCCH (SDCCH/4) Use the optional SDCCH capacity features such as the Adaptive Configuration of Logical Channel feature when available. Use Immediate Assignment on TCH, SDCCH first.

For manual dimensioning, use STS cell statistics Configure one SDCCH on the BCCH carrier and the others on the hopping layer (Non-BCCH) Use the Ericsson SDCCH Dimensioning guideline. Limited Internal 10 NPI Training – Retainability 2005-09-30 SDCCH Congestion Optimization The following issues are worth taking into account when analyzing SDCCH Congestion: ? Use LAPD STS statistics to evaluate LAPD congestion and optimize the LAPD Concentration factor ? Analyze border cells with a large amount of random access attempts resulting in SDCCH congestion. – Use Random Access optimization to solve the SDCCH congestion Take into account Timeslot priority when deciding where to configure SDCCH/8 Limited Internal 11 NPI Training – Retainability 2005-09-30 SDCCH Congestion Optimization S D C C H C C h e c k H L Limited Internal 12 NPI Training – Retainability 2005-09-30 SDCCH Congestion Optimization C h e c k c C Limited Internal 13 NPI Training – Retainability 2005-09-30 SDCCH Drops – Overview SDCCH Drops are classified into one of the following categories: ? ? ? ? SDCCH Drops because of Timing Advance SDCCH Drops because of Low Signal Strength SDCCH Drops because of Bad Quality SDCCH Drops due to Other Reasons

Limited Internal 14 NPI Training – Retainability 2005-09-30 SDCCH Drops – Overview Signaling Connection Set-up MSC Too high TA ? Wrong Cause Code? BSC Channel Required Y BTS Channel Request Random Access MS 1 2 3 N N Y Immediate Assignment Reject Too high processor load ? Activation of channel Step related RA counter Free ch. Available? N 4 Y 5n 6n SCCP Conn. Req SCCP Conn. Conf. Limited Internal Channel Activation successful? Channel Activation Ack. Y 5 Chan. Neg. Ack. N Channel Activation Channel Activation Ack. 6 Chan. Neg. Ack. Immediate Assignment Establish Indication

Step CMSESTAB counter 15 NPI Training – Retainability SABM, UA 2005-09-30 SDCCH Drops – Overview Assignment: Assignment to Serving Cell MSC BSC Channel Activation Channel Act. Ack. Y X Channel Act. Neg. Ack. BTS M Possible to assign channel? Assignment Request If TCH Congestion CNRELCONG is stepped (time out). N Assignment Command Establish Indication Assignment Complete Assignment Compl. RF Channel Release, old channel RF Channel Release Ack. SABM UA Limited Internal 16 NPI Training – Retainability 2005-09-30 SDCCH Drops – Overview Connection Release, Normal Disconnection

MSC Clear Command BSC Check Cause codes, if not HO successful or Call Control, step drop call counter, CNDROP BTS MS 1 Clear Complete Channel Release Deactivate SACCH DISC Release Indication RF Channel Release RF Channel Release Ack UA SCCP Rel. SCCP Rel. Ack. Limited Internal 17 NPI Training – Retainability 2005-09-30 SDCCH Drops – Overview Connection Release, Abnormal Disconnection MSC Clear Request Clear Command BSC Step drop call counter, CNDROP BTS Channel Release Clear Complete Deactivate SACCH DISC Release Indication RF Channel Release RF Channel Release Ack SCCP Rel.

SCCP Rel. Ack. Limited Internal 18 NPI Training – Retainability 2005-09-30 UA SDCCH Drop Optimization Analyze the following issues that could be possible reasons for SDCCH Drops: ? ? ? ? ? ? ? ? Low signal strength Interference Pathloss Imbalance between UL/DL High Timing Advance MS error or Subscriber behavior TCH Congestion Transmission Congestion (LAPD Concentration) Hardware or Transmission failures Limited Internal 19 NPI Training – Retainability 2005-09-30 SDCCH Drop Optimization The following issues are worth taking into account when analyzing SDCCH Drops: ? ? ? SDCCH Drops and TCH Drops often drop because of the same RF reasons, such as for example insufficient coverage Only use SDCCH power regulation and SDCCH HO when the network has good coverage BSC and transmission problems can impact SDCCH drops so investigate Transcoders, A-interface and LAPD SDCCH Drops on the hopping layer are normally showing worse values than SDCCH on the BCCH Limited Internal 20 NPI Training – Retainability 2005-09-30 SDCCH Drop Optimization C h e c k S C Limited Internal 21 NPI Training – Retainability 2005-09-30 SDCCH Drop Optimization B C Limited Internal 22 NPI Training – Retainability h e 2005-09-30

TCH Drop – Overview Connection Release, Normal Disconnection MSC Clear Command BSC Check Cause codes, if not HO successful or Call Control, step drop call counter, TFNDROP BTS MS 1 Clear Complete Channel Release Deactivate SACCH DISC Release Indication RF Channel Release RF Channel Release Ack UA SCCP Rel. SCCP Rel. Ack. Limited Internal 23 NPI Training – Retainability 2005-09-30 TCH Drop – Overview Connection Release, Abnormal Disconnection BTS Step drop call counter, TFNDROP MSC Clear Request Clear Command BSC Channel Release Clear Complete Deactivate SACCH DISC Release Indication RF Channel Release RF Channel Release SCCP Rel .

SCCP Rel . Ack . Ack UA Limited Internal 24 NPI Training – Retainability 2005-09-30 TCH Drop – Drop Call Reasons The TCH Drop Call reasons has the following priority order: ? ? ? ? ? Excessive TA – – – – – – TA > TALIM cell parameter SSUL < LOWSSUL (BSC parameter) SSDL < LOWSSDL RxQualUL> BADQUL (BSC parameter) RxQualDL> BADQDL None of the above Non radio-related Low signal strength in downlink and/or uplink Bad quality in downlink and/or uplink Sudden loss of connection Other – Limited Internal 25 NPI Training – Retainability 2005-09-30 TCH Drop – Drop Call Reasons

The TCH Drop Call reasons counters: SS uplink -60 MS sensitivity TxDISSDL LOWSSUL -104 -110 -111 -115 -110 Limited Internal TxDISSBL LOWSSDL TxDISSQADL TxDISSQAUL TxDISSQABL TxDISSUL BTS sensitivity SS downlink -104 -104 26 NPI Training – Retainability -60 2005-09-30 TCH Drop parameters ? RLINKT Radio Link Tim e -out Limited Internal 27 NPI Training – Retainability 2005-09-30 TCH Drop parameters RLINKT ? The MS sends measurement reports regarding the signal strength of neighbor cells every 480 ms ? If the BTS does not receive a measurement report the RLINKT timer is decreased by 1. If a new report is received the timer is increased by 2. ? Leaky bucket. When reaches 0 call is dropped Limited Internal 28 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization ? Analyze the following issues that could be possible reasons for poor TCH Drop performance: – – – – – – – – – Low Signal strength on Uplink/Downlink Interference on Uplink/Downlink Excessive TA Incorrect/Not optimum Parameter settings for example power regulation Missing Ncells or Congestion in Ncells MS or MS Battery problems Subscriber Behavior Antenna/Hardware or Transmission faults Incorrect Installations

Limited Internal 29 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization ? The following issues often cause TCH Sudden Drops: – Very sudden and severe drop in signal strength, such as when – subscribers enter into buildings, elevators, parking garages, etc. – Very sudden and severe occurrence of interference or bad quality. – MS running out of battery during conversation. – Handover Lost – BTS HW faults. – Synchronization or Abis link fault (transmission faults). – MS Faults Limited Internal 30

NPI Training – Retainability 2005-09-30 TCH Drop – Optimization D r o C h e c k B Limited Internal 31 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization H Limited Internal 32 NPI Training – Retainability 2005-09-30 C h h a TCH Drop – Optimization L o w s Limited Internal 33 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – MOTS: MOTS MOTS_tool Limited Internal 34 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO:

AssignmentRequest HandoverCommand HandoverComplete HandoverCommand HandoverComplete HandoverCommand HandoverComplete HandoverCommand HandoverComplete ClearRequest ClearCommand IL01673 IL01673 IL04071 IL04071 IL00053 IL00053 IL04072 IL04072 IL02752 IL02752 IL02752 IL02752 IL04072 IL00053 IL04071 17:04:49 17:05:15 17:05:16 17:05:27 17:05:27 17:05:57 17:05:58 17:06:37 17:06:39 17:06:49 17:06:49 STSSTSDrop Drop Start Start Drop (Clear Request) because wrong decision to HO from IL04072 to IL02752. Solution: Inhibit that HO relation. : STS pegged drop in IL02752 : Actual drop occured south of IL04072 Limited Internal 35

Actual Actual dropdropposition position NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: BSIC Confusion • • • • In this example mobiles do not handover to the correct cell but to a cell whose frequency it measure previously. In RPMO, this can be seen from the drop table. For example in the map a mobile traveling south needed to handov er from IL0020. 2 to IL1058. 0. IL1058. 0 has BCCH 137, and IL0404. 3 has BCCH is 137. Mobile meas ured IL0404 previously, and this can be seen from RPMO measurement reports. When mobile needed to handover from IL0020. 2 to IL1058. , it act ually makes wrong handover to IL0404. 3. Limited Internal 36 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: Tier 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 cCallNr 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 597 14 EventName C ell IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 00442 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 IL 0044 2 Tid TA RQUL RQDL RLUL RLDL SQI BTSPR MSPC NrNg p RxLevDLcom

M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easurem tR en eport M easure m entR port e C learR que e st C learC m a o m nd 7 :1 :43 3 17 :1 :43 6 17 :1 :43 9 17 :2 :43 1 17 :2 :43 4 17 :2 :43 6 17 :2 :43 8 17 :3 :43 1 17 :3 :43 4 17 :3 :43 7 17 :4 :43 0 17 :4 :43 2 17 :4 :43 4 17 :4 :43 7 17 :5 :43 0 17 :5 :43 3 17 :5 :43 6 17 :5 :43 9 17 :0 :44 0 17 :0 :44 0 10 10 10 10 11 10 11 11 11 11 11 10 11 11 11 11 11 11 2 5 3 0 2 7 4 3 2 4 4 6 3 7 7 7 7 7 6 7 5 7 7 1 5 6 7 7 7 7 1 5 7 1 5 1 5 1 5 1 5 1 5 22 14 19 22 21 10 22 21 21 21 21 18 18 6 6 6 11 12 28 23 27 22 24 255 26 21 24 24 24 255 17 255 255 255 255 255 4 0 4 9 2 55 4 3 2 55 2 55 4 8 2 55 2 55 2 55 2 55 2 55 2 55 2 55 2 55 2 55 2 55 2 55 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 6 5 6 6 5 5 5 5 5 5 5 5 5 5 5 5 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 8 2 3 2 7 2 2 2 4 2 55 2 6 2 1 2 4 2 4 2 4 2 55 1 7 2 55 2 55 2 55 2 55 2 55 Dropped Call due to Bad Quality • • • • • All drops due to bad quality UL/DL can be seen easily from RPMO drop and measurement table. The table below is a example of a short call. Call ID is 59714, and it lasted about 47 seconds. We can easily see that RXQual DL was bad since the call started. In this market, RLINK timer set to 32. Therefore, there may be s ome measurement missing ~16 seconds before the clear command.

The table shows several missing report between starting from 17: 43:44 until 17:44:00. Limited Internal 37 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: cCallNr 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 96 48 cEventCount Event id EventName Cell Tid TA RQUL RQDL RLUL RLDL SQI BTSPR MSPC NrNg RxLevDLcomp 11 4 12 4 13 4 14 4 15 4 16 4 17 4 18 4 19 4 10 5 11 5 12 5 13 5 14 5 15 5 16 5 17 5 18 5 19 5 10 6 11 6 12 6 13 6 14 6 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 2 3

Ma ue e t e ot e s r mnRp r Ma ue es r mnRp r e t e ot Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma u es r mnRp r e e t e ot Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r Ma ue e t e ot e s r mnRp r C aRq et le r e u s C aC le r o mn m ad I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 003 L48 I 0 48 L 03 I 003 L48 I 003 L48 I 003 L48 I 003 L48 : 50 71 : 5 1 : 50 71 : 8 1 : 51 71 : 1 1 : 51 71 : 4 1 : 51 71 : 7 1 : 52 71 : 1 1 : 52 71 : 4 1 : 52 71 : 6 1 : 52 71 : 9 1 : 53 71 : 1 1 : 53 71 : 4 1 : 53 71 : 6 1 : 53 71 : 8 1 : 54 71 : 1 1 : 54 71 : 3 1 : 54 71 : 6 1 : 54 71 : 9 1 : 55 71 : 2 1 : 55 71 : 5 1 : 55 71 : 8 1 : 60 71 : 1 1 : 60 71 : 3 1 : 60 71 : 3 1 : 60 71 : 3 5 6 6 6 6 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 6 4 5 7 7 7 7 7 7 6 6 7 7 5 7 7 7 6 7 7 5 4 6 2 6 1 5 1 5 5 6 1 5 6 4 5 1 5 1 5 5 1 5 1 5 7 1 5 1 5 1 5 9 1 0 7 9 7 3 6 2 2 0 2 2 1 0 1 7 0 5 3 5 2 6 1 2 1 5 1 3 1 4 8 25 5 25 5 2 2 25 5 6 6 8 25 5 25 5 7 25 5 25 5 3 25 5 25 5 25 5 4 1 4 6 4 6 4 6 3 9 3 1 1 8 1 7 1 1 1 6 1 9 3 0 2 7 2 3 1 7 1 7 3 0 1 5 1 9 2 0 2 4 1 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 1 0 2 1 2 1 0 0 5 0 0 0 1 2 0 0 0 0 2 3 2 1 2 1 5 1 3 1 4 8 25 5 25 5 2 2 25 5 6 6 8 25 5 25 5 7 25 5 25 5 3 25 5 25 5 25 5 Dropped Call due to Bad SS • • • We can see the calls dropped due to low signal strength in RPMO. From measurement reports, we can see when there is a drop due to low signal strength UL/DL, or both links. In the table, if we look at the part before the clear request, w e can see that RLDL (RX level DL), and RLUL (RX level UL) is quite low. In this example this call d ropped due to low SS RX level both links. Limited Internal 38 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO:

Tier 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 cCallNr 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 717 63 EventName H n o rC m le a d ve o p te Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p r Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Ma u mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt Mau mn e o e s re e tR p rt C a e u st le rR q e C a o mn le rC m a d t Cell IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021

IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 IL 0 3 021 Tid 1 :5 :4 7 5 1 1 :5 :4 7 5 4 1 :5 :4 7 5 6 1 :5 5 9 7 :4 1 :5 :5 7 5 2 1 :5 :5 7 5 4 1 :5 :5 7 5 6 1 :5 :5 7 5 9 1 :5 :0 7 6 1 1 :5 :0 7 6 4 1 :5 :0 7 6 7 1 :5 :1 7 6 0 1 :5 :1 7 6 2 1 :5 :1 7 6 5 1 :5 :1 7 6 8 1 :5 :2 7 6 1 1 :5 :2 7 6 3 1 :5 :2 7 6 6 1 :5 :2 6 7 6 1 :5 :2 7 6 6 TA 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 RQUL 3 3 5 3 1 4 6 4 7 7 7 7 7 7 4 7 7 RQDL 1 5 6 7 1 2 1 5 5 1 5 1 5 1 5 1 5 1 5 6 1 5 1 5 RLUL 1 6 1 3 6 1 5 1 6 1 7 7 9 4 9 0 2 3 4 8 6 5 RLDL 1 7 1 8 1 1 1 1 4 1 4 1 8 9 7 25 5 25 5 25 5 25 5 25 5 4 25 5 25 5 SQI 4 2 4 9 4 1 25 5 4 4 4 7 3 8 25 5 4 3 2 4 1 2 25 5 1 4 25 5 1 3 25 5 2 0 BTSPR 2 3 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 MSPC 5 5 6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 NrNg 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 3 3 RxLevDLcomp 2 1 2 4 1 3 1 1 4 1 4 2 0 9 7 25 5 25 5 25 5 25 5 25 5 4 25 5 25 5 Dropped Call due to RLINK • • • • • In the table we can see drop that happened due to RLINK timer. In this example the call started on cell IL00231, and ended in t he same cell. The call lasted around 45 seconds. If we look at the last 16 seconds of the call, we can see severa l missing measurement reports.

If we see 255 or or RXQual=15 we can assume that these values ar e missing In this example we dropped the call due to low signal strength d ownlink Limited Internal 39 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: cCallNr me 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 27 2 Ca n l uy hne s B Hn oeCm a d adv r o m n Hn oeCme adv r o p t l e Ca n l uy hne s B Hn oe adv r Cm a d om n Hn oeCme adv r o p t l e Ca n l uy hne s B Hn oeCm a d adv r o m n Hn oeCme adv r o p t l e Ca n l uy hne s B Hn oeCm a d adv r o m n Hn oeCme adv r o p t l e Ca n l uy hne s B Hn oeCm a d adv r o m n Hn oeCme adv r o p t l e Ca n l hne Bs uy Hn oeCm a d adv r o m n EventNa I 0 53 L2 2 I 3 01 L0 7 I 0 53 L2 2 I 3 01

L0 7 I 0 53 L2 2 I 3 01 L0 7 I 0 53 L2 2 I 3 01 L0 7 I 0 53 L2 2 I 3 01 L0 7 I 0 53 L2 2 I 3 01 L0 7 I 0 53 L2 2 I 3 01 L0 7 I 0 53 L2 2 I 0 21 L4 7 I 0 53 L2 2 Cell I 053 L22 Cellr I 301 L07 I 053 L22 I 301 L07 I 053 L22 I 021 L47 1: 4 2 7 : 01 1: 4 2 7 : 01 1: 4 3 7 : 01 1: 4 9 7 : 01 1: 4 9 7 : 01 1: 4 9 7 : 01 1: 4 5 7 : 03 1: 4 5 7 : 03 1: 4 6 7 : 03 1: 5 1 7 : 01 1: 5 1 7 : 01 1: 5 1 7 : 01 1: 5 8 7 : 01 1: 5 8 7 : 01 1: 5 9 7 : 01 1: 5 3 7 : 02 1: 5 3 7 : 02 Tid essage CauseM 1 1 0 0 1 1 0 0 0 0 1 type subcell T HF ) C(R T HF ) C(R Type Channel T HF ) C(R T HF ) C(R T HF ) C(R T HF ) C(R C aRq et l r eu s e I 0 53 L2 2 1: 5 5 7 : 03 RD AI O I T RE E C NE F RN E MS A E ESG F I UE A R L T HF ) C(R C aCm a d l r om e n I 0 53 L2 2 1: 5 5 7 : 03

RD AI O I T RE E C NE F RN E MS A E ESG F I UE A R L T HF ) C(R Dropped Call due Handover Timer • • • • This timer expires ~11 to 14 seconds after handover command sent . When the timer expire, we can assume that handover command that was sent was not heard either by the cell, or by mobile. The table shows an example of a drop happened due to this reason . If we look the time stamp 17:05:23, we can see that we request channel from IL04271, and h andover was initiated the very same second. However, about 12 seconds after handover command, we can see tha t call drop. As we know, this can not be a RLINK timer drop because it is set to 32 (~16 secon ds).

Limited Internal 40 NPI Training – Retainability 2005-09-30 – T3103B1 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: Handover Timer – T3103B1 Limited Internal 41 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: cCallNr EventName 733 ChannelBusy 733 HandoverCommand 733 ChannelBusy 733 HandoverCommand 733 ClearRequest 733 ClearCommand Cell IL02813 IL04293 IL01831 IL04271 IL04271 IL04271 Cellr IL00423 IL01831 Tid 17:04:04 17:04:23 17:19:46 17:19:46 17:19:54 17:19:54 CauseMessage RADIO INTERFERENCE MESSAGE FAILURE RADIO INTERFERENCE MESSAGE FAILURE subcell type 1 1 ChannelType SDCCH TCH (FR) TCH (FR)

Dropped Call due Handover Timer – T3103B2 • • • • This timer usually expires ~ 8 to ~10 seconds after hand over co mmand request. When this timer expires, we can assume that the MS, or target ce ll heard HO command but we do not have any respond from them. In the table we can see that at 17:19:46 we have handover comman d from IL04271 to IL01831. We have clear request coming in 17:19:54 – 8 seconds after handover command Limited Internal 42 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: Handover Timer – T3103B2 Limited Internal 43 NPI Training – Retainability 2005-09-30 TCH Drop – Optimization

Investigate TCH Drop Performance – RPMO: Cell 973 FR FR FR OL UL Call set -up 17:31:54 Actual drop moment 17:32:53 Call dropped 17:32:59 Cell 2431 HR FR FR FR FR HR Major mistake 17:32:39 17:31:50 :00 :10 Limited Internal 44 :20 :30 :40 :50 2005-09-30 17:33:00 NPI Training – Retainability TCH Drop – Optimization Investigate TCH Drop Performance – RPMO: Cell 973 FR FR HOVERCNT HOVERSUC TFCASSALL TFMSESTB TFCALLS + SUB TFV3CALLS+SUB (TFV2CALLS+SUB TFV1CALLS+SUB TFCONGSHO+SUB? ) FR TFCALLS TFV3CALLS TASSALL TCASSALL HOVERCNT HOVERSUC TFMSESTB+SUB THMESTAB+SUB THCALLS + SUB THV3CALLS+SUB TFCALLS + SUB TFV3CALLS+SUB (TFV2CALLS+SUB TFV1CALLS+SUB TFCONGSHO+SUB? ) Cell 2431

TFCALLS + SUB TFV3CALLS+SUB TFMESTAB (dep)? TFCALLS TFV3CALLS HR FR FR FR TFCALLS TFV3CALLS FR HR HOVERCNT HORTTOCH HOVERCNT HOVERSUC TFMSESTB HOATFRHRAMR HOSUCFRHRAMR HOATHRFRAMR HOAATOL HOSUCOL THMSESTB THV3CALLS THCALLS are not stepped THNDROPSUB TFMSESTB 17:31:50 :00 :10 Limited Internal 45 :20 :30 :40 :50 2005-09-30 17:33:00 NPI Training – Retainability TCH Drop – Optimization Investigate TCH Drop Performance – DIP DIP Limited Internal 46 NPI Training – Retainability 2005-09-30 Handover – Overview ? The fundamental concept of mobile communications is the mobility, where the person using the phone moves around being handed over between cells ?

HANDOVER is the process that ensures that the user is placed on the best server and that the following requirements for mobile communications are fulfilled: – Coverage: to provide a connection with sufficient signal strength – Speech Quality: to avoid disturbances – Capacity: to even out the traffic load ? LOCATING Is the software algorithm that determines Handover Decisions Limited Internal 47 NPI Training – Retainability 2005-09-30 Handover – Overview 1 HODetect BS I BC C, S CH S u eas H M CC SA rt epo re R 2 HO FA Acc CC es H s and mm Co HO CH C FA Or 3 HO FA Com CC pl H ete 3 nd ma m Co HO CH C FA If all signaling goes well, call is established on target cell and old channel is released. Limited Internal 48

Mobile has moved too far away from serving site FACCH can’t reach (C/I-wise) Drop! NPI Training – Retainability 2005-09-30 Handover – Locating Overview For all reported neighbor cells n For serving cell s Locating ? Basic Handover Candidate list Discard n No M inimum level criterion fulfilled? Yes Penalty evaluation W ait until ranking of neighbor cell is done Yes Rank n according to L-criterion including LOFFSET and LHYST Signal strength above SUFFICIENT level including TROFFSET and TRHYST? No Rank n according to Kcriterion including KOFFSET and KHYST L-cells K-cells Yes More neighbors? Best neighbor used for serving cell sufficient condition No No Serving cell is K-cell

Signal strength above SUFFICIENT level? Yes Serving cell is L-cell L-cells K-cells Limited Internal 499702661 NPI Training – Retainability 2005-09-30 Handover – Locating Overview Locating ? Types of cell borders K-K border transition border (K-L border) equal L equal K L-L border B A effective sufficient level from B to A transition border (K-L border) effective sufficient level from A to B Limited Internal 50 NPI Training – Retainability 2005-09-30 Handover – Locating Overview Locating – Basic Ranking: Ericsson 3 ? The first three stages of the algorithm are performed in exactly the same way as Ericsson 1, but Ericsson 3 takes only the signal strength in account: 1.

Correction of the BTS output power for downlink measurements 2. Evaluation of the Minimum Signal Strength condition 3. Subtraction of the signal strength penalties 4. Signal Strength Evaluation 5. Combination into a basic ranking list sorted by a descending order of SS Limited Internal 51 NPI Training – Retainability 2005-09-30 Handover – Locating Overview Locating – Basic Ranking: Ericsson 3 R A N K = S S _ D O WsN s R A N K = p _ S S _ D O W N O F F S EsT – H Y S T,n n n ,n s w h e re H Y S T = H IH Y S T if rx le H Y S T S E P n? v H Y S T = L O H Y S T if rx < H Y S T S E P n le v Limited Internal 52 NPI Training – Retainability 2005-09-30 Handover – Locating Overview

Locating – Auxiliary Radio Network functions evaluation Six auxiliary radio network functions are incorporated in the locating software: • Assignment to another cell • Hierarchical cell structures • Overlaid and underlaid subcells • Intra-cell handover • Extended range • Cell load sharing Limited Internal 53 NPI Training – Retainability Penalty list Initiations Measurement results Filtering Urgency condition Basic ranking Auxiliary radio network functions evaluations Organizing the list Sending the list Allocation reply 2005-09-30 Handover – Locating Overview ? Locating – Auxiliary Radio Network functions evaluation Limited Internal 54 NPI Training – Retainability 2005-09-30 Handover – Locating Overview Sa ii r rd nwku tosr i ula aoe o f ni na xx y i t r c e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ?

Locating – Auxiliary Radio Network functions evaluation P a ls e ly t nt i I ii tos na n ti Categorization 1: The candidates in the ranking list are divided into categories. The signal strength is used to •Asetmtt a t ecl for the neighboring cells. The si nthe onh e s e categories g n or l existing categories are: Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i •Ha– i a esuuCell with a higher ranking value than i rrh lcl t cell:e e ccBetterrcrs l t •Ora aservinga sbthe candidate list. v l i nu e i u e e d dn r cell in ls dl d cl – Worse cell: Cell with a lower ranking value than •I ta – eh d e in the candidate list. clserving cell r l a or nv •Ee –da e cell: The cell serving the connection. xn rServing t d n e g •C l asa g e o hi l d rn l ? Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y These categories are later used in evaluations and selection of cause values Limited Internal 55 NPI Training – Retainability 2005-09-30 Handover – Locating Overview Locatingaoe o u tosr Sa ii r rdCell r f ni na i ula – nwk c Sharing Evaluation x x y i t Load e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r The cell load sharing evaluation is performed after the normal ranking procedure.

The •Aevaluationh cl performed if si ne t a t e e s mt on is only g n or l •Ha–i a esuus i rrh lcl load r e cccelll t c sharing is active for the cell rte •Ora aif u e i sb ls v l i n no urgency conditions apply and e – dn ra u e d dl d cl – if the channel is a TCH where the channel mode •I ta – eh d e n clisa o r r l “speech/data” nv ? xn da e Ae g •Ee channel in a multislot configuration is not t d rn evaluated. •C l asa g Further, no evaluation is e o hi l d rn l performed at request of a candidate list for assignment. Limited Internal 56 NPI Training – Retainability P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i

Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y 2005-09-30 Handover – Locating Overview Locatingaoe o u tosr Sa ii r rdCell r f ni na i ula – nwk c Sharing Evaluation x x y i t Load e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ? Only candidates that fulfill the following •Aconditionsh clinvolved in the evaluation: si ne t a t e e s mt on are l g n or – •Haha esuus is ranked Worse i rr i lcl candidate e ccThe t cr l rte – The candidate is Internal •Ora aIt u e i inu esame cell layer as serving cell v l i n existsd b ls e – dn ra sthel d dl c •I ta –clIt a o r ‘handover due to cell load sharing’ n – eh d e r l accepts nv ? n da e The g •Ee ern t d evaluation is then performed as a new ranking •C l asa g reduced hysteresis areas e o hi with l d rn l between serving cell and the neighboring cells. Limited Internal 57 NPI Training – Retainability P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y 2005-09-30 Handover – Locating Overview Locatingaoe o f ni na Sa ii r rdOverlaid/Underlaid Evaluation i ula – nwku tosr xx y i t r c e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ?

The evaluation is only performed if the •Aservinga t ecl an overlaid and underlaid si ne t cell r e s mt onhhas g n o l •Haha esuus i subcell lstructure. er i lcl t cr r cc rte ? An •Ora evaluation b lperformed to determine if a v l i a u e i sis l e dn n ra u e d dl d c s subcell change (overlaid to underlaid or •I ta – eh d e n cl a o r r l nv underlaid to overlaid) is desired. •Ee ern t d g ? xn da e The criterion is based on the downlink signal •C l asa gtiming advance measurements from e o hi l d rn l strength, the serving cell and the traffic load in the cell. Limited Internal 58 NPI Training – Retainability 2005-09-30 P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t

Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y Handover – Locating Overview Locating r Overlaid/Underlaid Sa ii r – d nwku tosr Evaluation i ula aoe o f ni na xx y i t r c e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ? P a ls e ly t nt i I ii tos na n ti If the serving cell is co-sited with a neighboring cell that has a subcell structure, then locating evaluates if the •Ahandover nh cl proposed to the overlaid or si ne t a t ebe s mt o shall e g n or l •Haha esuus subcell. i underlaidlneighboring er i lcl t cr r cc rte ?

If the MS is located in the overlaid subcell and a bad •Ora a urgencysb ls Locating proposes a subcell v l i nu e i u e e d dn ra occurs, quality dl d cl •I ta – eh d e nchange a o overlaid to underlaid subcell to prevent r cl from r l nv the MS from remaining on connections with bad •Ee ern xn da e t d g quality. •C l timer rn l a his used to prevent an immediate return back to l ? e o sa g A d i the overlaid subcell. Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y Limited Internal 59 NPI Training – Retainability 2005-09-30 Handover – Locating Overview Locatingaoe o f nHandover Evaluation Sa ii r rdIntracellcosr i ula – nwku t na xx y i t r i e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ?

The Intracell Handover evaluation is not •Aperformedh cl si ne t a t e e s mt on at assignment and otherwise only g n or l •Haha esuus i performed cr er i lcl t if intracell handover is allowed for r cc l r t e the current subcell. •Ora a u e i sb ls v l i n n ra u e e d d dl d cl ? The criterion for determining if an intracell •I ta – eh d e n cl a o r r l nv handover is desired is based on uplink and •Ee ern quality and signal strength xn da e t d g downlink •C l asa g e o hi l d rn l measurements from the serving cell. P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y Limited Internal 60 NPI Training – Retainability 2005-09-30 Handover – Locating Overview

Locating r Intracell Handover Sa ii r – d nwku tosr Evaluation i ula aoe o f ni na xx y i t r c e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ? P a ls e ly t nt i I ii tos na n ti The criterion is fulfilled when the quality is worse than could be expected from the signal strength level. There •Aare parameterscl prevent too many consecutive si ne t a t e e s mt onh to g n or l •Haha esuus in a sequence during a connection. i intracell handovers er i lcl t cr r cc l r t e ? If the MS is located in the overlaid subcell and the •Ora a u e i sbconsecutive intracell handovers v l i n of allowede e d dn ra u ls number dl d cl •I ta – eh d e nhave beeno r r cl a executed then Locating proposes a subcell l nv hange from overlaid to underlaid subcell to prevent •Ee ern remaining on connections with bad xn dafrom t dMS g e the quality. •C l asa g e o hi l d rn l ? A timer is used to prevent an immediate return back to the overlaid subcell. Limited Internal 61 NPI Training – Retainability Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y 2005-09-30 Handover – Locating Overview Sa ii r rd nwku tosr i ula aoe o f ni na xx y i t r c e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ? Locating – Assignment to Other Cell P a ls e ly t nt i I ii tos na n ti

The normal Locating is used in order to find the most suitable cell at the call setup ? sg e t a t e e •AIf nbetternhthan the serving cell is found during the s amt o cell rcl i n o l call setup signaling, that cell will be the first one in the •Haha esuus list. This is called Assignment to a i Locating lcandidate er i lcl t cr r cc rte •Ora acell. e i sb ls v l i nu ra u e e d dn l d cl d better ? nAlso worse vr •I ta – eh dcells can be found, and at congestion in the r cl a o l n e serving cell or in the better cell, the call can be setup in •Eeworseg This is called Assignment to a worse cell. xn da e t d rncell. a e •C l asa g at a large distance from the nominal l d rn l ? o hi cells However, cell are not allowed to remain as candidates. This is controlled by the parameter AWOFFSET. Limited Internal 62 NPI Training – Retainability Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y 2005-09-30 Handover – Locating Overview Locating – Hierarchical Cell Structures Sa ii rHCS nwku tosr the possibility to give priority x Theyaoe o f provides x i t r c e ? i ula rd feature ni na i crtorcells t e ctnsfwe n pad that aregothe: oot i hl a nott a strongest but provide sufficient en o i r signal strength levels ?

The appropriate level of the sufficient signal strength •Alevelstt a t ecl si nemainly depends on the co- and adjacent s m onh e g n or l •Haha esuus surrounding cells i interference from the er i lcl t cr r cc l r t e ? With low interference it is the noise level with a safety •Ora a u e i sb sufficient signal strength levels v l i nthatra thee e d dn l du ls margin d set cl ? nEach l ashould •I ta – eh d e be associated with a LAYER r ccelln vr l o ? The Layer could be defined by the traffic that the cell •Ee ern with just a basic ranking, how much traffic the xn da e t d g captures cell dimensioned for and how much the cell •C l asa g e o arern l dhi l interfere with the rest of the network ? The lower the layer the higher the priority Limited Internal 63 NPI Training – Retainability P a ls e ly t nt i I ii tos na n ti

Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y 2005-09-30 Handover – Locating Overview Locating – Removal of candidates Sa ii r rd nwku tosr i ula aoe o f ni na xx y i t r c e i crot d t e ctnsfwe of candidates from the n pa n o i removal o reasons a t r The r ei hl for go a: list are: •Ai ne t a t ecl sgmt onh e s n or l •Haha esuus er i candidate rc l rte ? i Theclcl t cr belongs to a system type not •Ora a u eby u emobile. v l i n n ra sb ls e d d dl i thel supported d c ? Evaluation r •I ta – eh d e BSC parameters and timers r cl a o of l nv controlling •Ee ern handover, i. e. if it is allowed to xn da e t d g make i •C l asa g e o hhandover on SDCCH etc. The l d rn l evaluated parameters are IBHOSICH, SCHO, ASSOC, IBHOASS, TALLOC and TURGEN. Limited Internal 64 NPI Training – Retainability P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y 2005-09-30 Handover – Locating Overview Locating – Removal of candidates

Sa ii r rd nwku tosr i ula aoe o f ni na xx y i t r c e The reasons for removal of candidates from the list are: i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r Evaluation of co-sited neighbors. Three checks are •Aperformed:oecl si ne t a t r e s mt onh l g n ? – P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t If average timing advance exceeds the MAXTA value •Haha esuus cell. i rr i for l t co-sited e cclcthercr l te – If average timing advance is less than the TALIM value •Ora a u e i sb and greater than or equal to the TALIM v l i n n ra u e e d for serving cell ls d dl d cl value for the •I ta – cl h d eis worse and in the same cell layer as serving n – e the o r co-sited cell. l a cell nv If •Ee ern and the average timing advance exceeds the xn da e t d cell g TALIM value for the co-sited cell. Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y •C l asa g removal of candidates if the MS is l d rn l ? e o hi and Evaluation classified as a fast moving mobile (if this feature is used). Limited Internal 65 NPI Training – Retainability 2005-09-30 Handover – Locating Overview Locating – Categorization 2 Sa ii r rd nwku tosr i ula aoe o f ni na xx y i t r c e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r ?

The cells in the candidate list are then organized in the following three categories: •Ai neAbove ecl sgmtt a t S: e s – nonh Neighboring cell above serving cell in or l •Haha esuus list i rr i lcl candidate e ccthel t cr rte •Ora aBelowl S:sb ls v l i nu e i Neighboring cell below serving cell in e – dn ra u e d d d cl the candidate list •I ta –clS:a o r cell n – ehServing r l nv de •Ee ern xn da e t d g •C l asa g e o hi l d rn l P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y Limited Internal 66 NPI Training – Retainability 2005-09-30 Handover – Locating Overview

Locating – Ordering the candidate list Sa ii r rd nwkuRequeste i ula aoDescriptioncosrArrived x Indication i Assignment t na e o f ni t r 1x y i cr2ot d t e ctnsfwe n pa i hAWa go urgency o r e n Excessive TA a: l state t r oi 3 •Ai ne t a t ecl sgmt onh e s n or l •Haha esuus i rr i lcl t cr e cc l r t e •Ora a u e i sb ls v l i n n ra u e e d d dl d cl •I ta – eh d e n cl a o r r l nv •Ee ern xn da e t d g •C l asa g e o hi l d rn l 4 5 detected Bad Quality urgency detected OL/UL subcell change or ICHO requested P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y Limited Internal 67 NPI Training – Retainability 2005-09-30 Handover – Locating Overview

Locating – List preparation Sa ii r rd nwku tosr i ula aoe o f ni na xx y i t r c e i crot d t e ctnsfwe n pa i hl a go a: o r en o i t r •Ai ne t a t ecl sgmt onh e s n or l •Haha esuus i rr i lcl t cr e cc l r t e •Ora a u e i sb ls v l i n n ra u e e d d dl d cl •I ta – eh d e n cl a o r r l nv •Ee ern xn da e t d g •C l asa g e o hi l d rn l P a ls e ly t nt i I ii tos na n ti Msrmt eu e aen rsls et u Fe g it r l i n Ueccnii n r n odo g y t Bi r nn acakg s i Aii r r d ula ai x y o nt o f ni n e r uc s wk to e lan vuto a i s O ni g es r az t l t gi nhi S dg es ei t l t nn h i Actor p lo i nel l a y Limited Internal 68 NPI Training – Retainability 2005-09-30

Handover – Locating Overview Locating – Sending the list • If th e can did ate list is em pty (i. e. serving cell is the best) th e cand id ate list is no t sent to the ce ntral processo r. • T h e first ce ll in the ca ndidate list is the “b est” ca ndidate . A t con gestion the n ext cell in th e ca ndidate list is tried. P e n a lty lis t In itia tio n s M ea su re m e n t re su lts F ilte rin g U rg e ncy co n d itio n B asic ra n kin g A u xilia ry ra d io n e tw ork fu n ctio n s e va lua tion s O rg a niz ing th e list S e nd in g th e list Allo ca tio n re p ly Limited Internal 69 NPI Training – Retainability 2005-09-30 Handover – Locating Overview

Locating – Allocation reply • A t s u c c e s s a p e n a lty lis t is tra n s fe rre d fro m th e lo c a tin g in d iv id u a l to th e n e w o n e . If th e h a n d o v e r re a s o n w a s d u e to u rg e n c y a p e n a lty fo r th e a b a n d o n e d c e ll m u s t b e in c lu d e d . T h e o ld lo c a tin g in d iv id u a l is th e n d e le te d . • A t in te r-B S C h a n d o v e r it is n o t p o s s ib le to s e n d th e p e n a lty lis t. H o w e v e r it is p o s s ib le in d ic a te if th e c a u s e o f th e h a n d o v e r w a s d u e to b a d q u a lity o r e x c e s s iv e tim in g a d v a n c e . T h e p e n a ltie s o f th e n e w c e ll w ill th e n b e u s e d