Slide title In CAPITALS 50 pt Slide subtitle 32 pt ANALYSING EFFECTS OF MALFUNCTIONS ON THE PERFORMANCE OF UMTS RADIO ACCESS NETWORKS Author: Antti Keintola Supervisor: Professor Sven-Gustav Häggman Instructor: M.Sc. Anna Merjamaa

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Agenda  Background  Research problem and objectives  Methods  Analysis  Results  Summary

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Background  3G networks are launched all over the world  Technology is complex and still somewhat immature  Not much experience in operating and troubleshooting the network  Networks are not performing at the optimal level  Faults and failures occur  Troubleshooting is time consuming and finding the root cause is difficult  Performance statistics is sometimes the only source of information available

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Research problem and objectives  What faults contribute most on the performance degradation?  Is it possible to find the cause of the failure by inspecting statistics?  What actions should be performed to improve performance?

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Methods  Counter data was collected from a live network –7 RNCs, 1906 Node Bs –28 day period –Only daily statistics, not hour or quarter data available  Improvements made simultaneously  Data analysed with spreadsheet tool –Laborious, slow –Need for dedicated tool

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola  Key Performance Indicators defined: –Call Completion Success Rate (CCSR) –Accessibility –Retainability  CCSR = Accessibility * Retainability Methods

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Analysis – network  The net degradation of performance were calculated and dominant days were identified  Detailed analysis focused on days highlighted with red and yellow DayNet contrib. DayNet contrib. 13,50%153,85% 23,69%163,92% 32,91%174,08% 42,63%183,20% 53,29%192,76% 63,61%203,40% 74,14%213,99% 84,52%223,75% 93,67%233,91% 103,43%243,25% 112,80%253,41% 124,81%263,46% 133,36%273,33% 143,87%283,44%

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Analysis – accessibility  Accessibility was studied first –Almost all accessibility failures related to RRC rejects

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Analysis – RRC at RNC level  Six distinct faults were identified by analysing RNC RRC statistics

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Analysis – retainability  Speech and packet drops were studied separately

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Analysis – Radio Access Bearers  Drop rate analysis were done at RNC level –Basically RAB releases were investigated

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Results – accessibility failures  Following defects were identified and their net contribution to the overall performance were calculated  Transmission fault affects three out of seven RNCs, hence higher figure  Software and hardware defects have small impact on the overall performance FaultNet contribution Parameter fault2,19% Software fault1,09% AAL2 fault1,62% Hardware failure 0,95% Cabling fault in core network 1,20% Transmission fault 4,22%

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Results – accessibility failures

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Results – retainability failures  Speech calls  Packet connections FaultNet contribution Software fault1,66% Hardware failure 1,25% Transmission fault 6,68% FaultNet contribution Design fault10,72% Parameter fault11,29%

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Results – retainability failures

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Summary  Defects with significant impact on the network performance were identified  Impacts on the performance were calculated  Man-made defects have more severe impacts than software or hardware faults  The reasons for man-made faults should be worked out  Working instructions and procedures should be revised and improved  Need for dedicated tool to analyse data from customer network

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Traffic properties

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Traffic properties

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Traffic properties

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola Traffic properties

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2005Antti Keintola