© Omnitele Ltd UMTS Quality of Service enabling new mobile applications CANTO St. Kitts & Nevis, 19 th – 22 nd June 2005 Heidi Lagerström,

© Omnitele Ltd Agenda 1.Introduction to UMTS New services 2.Quality of Service (QoS) in UMTS network Using QoS to improve service quality 3.Service quality measurements in UMTS network Different ways to measure service quality Defining correct Key Performance Indicators (KPIs) 4.Conclusions

© Omnitele Ltd New generation of mobile networks UMTS New data services are driving up traffic in mobile networks ARPU generated by data users is rising Rise in traffic will bring challenges in maintaining acceptable quality of service Service quality is closely tired to new service acceptance Need to build more network capacity!

© Omnitele Ltd Introducing new services GSMGPRSEDGEUMTSHSDPA Voice & SMS MMS picture/video xHTML browsing Application downloading Presence/location WEB browsing Corporate data access Streaming audio/video Video sharing Video telephony Real-time IP Multimedia and games Broadband in wide area A number of mobile services are bearer independent in nature 3G-specific services take advantage of higher bandwidth and real-time QoS Improved performance, decreasing cost of delivery Higher bit rates

© Omnitele Ltd Agenda 1.Introduction to UMTS New services 2.Quality of Service (QoS) in UMTS network Using QoS to improve service quality 3.Service quality measurements in UMTS network Different ways to measure service quality Defining correct Key Performance Indicators (KPIs) 4.Conclusions

© Omnitele Ltd Why do we need QoS? UMTS networks support services with very different performance requirements –Real-time services require performance guarantees –Customer acceptance closely tied to service quality Optimal usage of network resources –Radio resources scarce –Cost-effectiveness –Return of investment Service and user differentiation –Meet different needs of customers (e.g. business vs. consumer) –Support different services (real-time vs. best effort) Competitive advantage!

© Omnitele Ltd QoS Traffic Classes Traffic classCharacteristicsExample application ConversationalPreserve time relation between information entities of the stream. Conversational pattern (stringent and low delay) Speech Video calls StreamingPreserve time relation between information entities of the stream. Real-time streaming video InteractiveRequest-response pattern. Preserve payload content. Web browsing BackgroundDestination is not expecting the data within a certain time. Preserve payload content. File downloading Demanding Delay Jitter Demanding Bit rate Jitter Tolerant Delay and bit rate can vary Integrity Easiest Delay and bit rate can vary Integrity

© Omnitele Ltd QoS Profile Attributes R99 QoS attributeExample value Residual BER10 –5 SDU error ratio10 –4 Delivery of erraneous SDUsNo Maximum SDU size (octets)1500 Delivery orderNo Transfer delay100 ms (conversational) 280 ms (streaming) ARP1, 2 or 3 Traffic ClassConversational, streaming, interactive, background THP1, 2 or 3 (same as ARP) Maximum allowed bit ratee.g. 64, 128 or 384 kbps Maximum guaranteed bit ratee.g. 64, 128 or 384 kbps Depends on operator’s QoS strategy Depends on the QoS strategy and UE/RNC capabilities

© Omnitele Ltd QoS Differentiation Conversational RAB Streaming RAB Interactive RAB, THP/ARP = 1 Interactive RAB, THP/ARP = 3 Background RAB MMS Web browsing Push-to-talk Streaming Video telephony Each service gets the treatment it requires according to the QoS profile Network resources are shared according to the service needs Network resources can be used more efficiently

© Omnitele Ltd Operators’ QoS Strategy Conversational RAB Streaming RAB Interactive RAB, THP/ARP = 1 Interactive RAB, THP/ARP = 3 Background RAB RNC 3G GGSN 3G SGSN Application server Node B HLR User profiles are stored in HLR. Each user can have several user profiles, which correspond to different services and are mapped to different bearers according to the operator’s strategy. Operators can practise user differentiation by giving each user set of QoS profiles, which he/she is entitled to use Operators can practise service differentiation by mapping each service to the bearer that meets its requirements Meet the needs of different customers Offer each service the quality it requires Optimise network resource usage

© Omnitele Ltd Agenda 1.Introduction to UMTS New services 2.Quality of Service (QoS) in UMTS network Using QoS to improve service quality 3.Service quality measurements in UMTS network Different ways to measure service quality Defining correct Key Performance Indicators (KPIs) 4.Conclusions

© Omnitele Ltd Measuring network performance RNC 3G GGSN 3G SGSN Application server Node B UTRANCore nwExternal nw E2E service quality, QoE Performance statistics from application server Network statistics from different counters and interfaces Customer feedback Network Performance Monitoring  Optimisation

© Omnitele Ltd RNC 3G GGSN 3G SGSN Application server Node B UTRANCore nw External nw Drive tests Coverage Service availability Mobility Walk tests Service availability (e.g. city center) Mobility (low speed) Benchmarking Comparative data Competitor evaluation End-to-end field measurements Hot spot tests Service performance Indoor coverage Congested places (e.g. railway stations, shopping malls)

© Omnitele Ltd Defining the right KPIs Different services have different quality requirements –KPIs must be defined separately for each of the key services KPI categories –Service Accessibility –Service Integrity –Service Retainability With inadequate performance indicators and monitoring –Hidden problems in network performance and user perceived quality of service –Poorly defined indicators may show better quality than in the reality Incorrect formulas and counters Unreasonable measurement periods (too much averaging etc.)

© Omnitele Ltd Example: Voice Services - CS Customer demand IndicatorMeasure Service accessability Availability & Coverage Blocked calls Call setup delay Ec/No, RSCP Admission control RAB assignment Service integrityVoice qualityNoisy frames (FER), MOS Service retainability Dropped callsHandover failure No coverage Interference

© Omnitele Ltd Example: Data Services - PS Customer demandIndicatorsMeasures Service accessability Availability & Coverage Blocked service access Service access delay Ec/No, RSCP Admission control Attach, PDP context activation, IP service setup Service integrityVideo quality Audio quality Web page download time sending time, etc. BLER, FER, throughput, delay, jitter Service retainability Dropped data connection Connection timeouts Dropped PDP context/attach No coverage Handover failure

© Omnitele Ltd WCDMA vs GSM field measurements GSMWCDMA BCCH carrierCPICH TCHDCH PDCHDCH, Common RACH/FACH RXLevRSCP C/I on BCCHCPICH Ec/No RXQual/ BERDCH BLER MS TX powerUE TX power HO successSHO/HHO division, ISHO IFHO success, CM usage Throughput (GPRS)Throughput per RAB

© Omnitele Ltd Example: CPICH coverage – Ec/No According to Ec/No values both operators have good coverage. Couple of RED areas, which need to be further investigated! Operator 1 Operator 2 If large interference areas are generated, the problem could be minimised later by adjusting the antenna direction or height, or by down tilting the antenna or by slightly tuning the pilot power levels.

© Omnitele Ltd Agenda 1.Introduction to UMTS New services 2.Quality of Service (QoS) in UMTS network Using QoS to improve service quality 3.Service quality measurements in UMTS network Different ways to measure service quality Defining correct Key Performance Indicators (KPIs) 4.Conclusions

© Omnitele Ltd Conclusions UMTS networks bring more capacity to GSM/GPRS mobile networks –Enables operators to launch new services –Increases the ARPU generated by subscribers –Offers better service quality In 3G networks QoS management is required –Real-time services require QoS guarantees –Need to support different kinds of services –With QoS mechanisms operators can use their network resources more efficiently and gain competitive advantage To maintain and improve the network performance and user experienced service quality constant monitoring and performance follow-up is needed –Successful network measurements are based on correct KPI definitions –A combination of end-to-end field measurements, interface probes, network element counter statistics and customer feedback is required

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© Omnitele Ltd How can Omnitele help you? Network acceptance testing Network parameter planning Network audits for GSM/GPRS/EDGE and UMTS networks –KPI analysis –Drive tests –Hot spot tests –Benchmarks Network counter analysis Network optimisation