VIEWS: 513 PAGES: 23 CATEGORY: Mobile Devices POSTED ON: 2/16/2011
EVDO (EV-DO) is actually the abbreviation of three words: Evolution (Evolution), Data Only. Its full name: CDMA2000 1xEV-DO, CDMA2000 1x Evolution is (3G) of a path of a stage. This path has two development phases, the first is called 1xEV-DO, the "Data Only", it allows operators to use an IS-95 CDMA or CDMA2000 same carrier frequency bandwidth can be up to 2.4Mbps of Prior to the data transfer rate, ITU ITU has now been accepted as an international 3G standard, and already have the condition of business. The second phase is called 1xEV-DV. 1xEV-DV means "Data and Voice", it can be in a CDMA carrier frequency to support both voice and data.
Carrier Grade VoIP on EV-DO Rev A Lucent Technologies Michael Recchione Director, Converged Networks and Services Research firstname.lastname@example.org Overview • Our initial excitement and effort was focused on air-link capacity considerations – “The wonderful thing about a dancing bear is not how well he dances, but that he dances at all.” - Mark Twain • We’re now fairly satisfied that the air-link capacity is comparable to or greater than 1x Circuit Voice – Some simulation results looking at capacity and delay • Need to take the next step to create a viable set of voice services. • What is “Carrier Grade VoIP”? 2 Simulation Parameters • Detailed computer simulations carried out to study the capacity and delay performance – Harvard speech sentences digitized as voice input with voice activity factor of 47.6% (38%, 5%, 0%, 57% for full, 1/2, 1/4, and 1/8 rates) • Consistent with field measurement of EVRC coder – 1/8 rate frames are not transmitted, resulting in an effective voice activity factor of 40.5% (15% gain) – ROHC used to reduce the header overhead – RLP retransmission disabled 3 Performance Criteria • Each frame is defined as a 20-ms speech frame regardless of the packet size for delivery • 2% final average frame erasures maintained – frame errors due to RF • small due to HARQ – delay of packet delivery FER Due to Delay 2% Total • The design target is for 98% of users to have an average erasure rate less than 2% regardless whether the erasures are from FER FER Due to RF or from delay of packets • The objective is to meet the delay criteria for the “users satisfied” range defined in ITU document G.114 4 Voice Quality (ITU G.114 Delay Guideline) 100 Very Satisfied 90 Lucent VoIP E-model rating R Target Satisfied 80 Internet VoIP Some Quality unsatisfied 70 Many unsatisfied 60 Nearly all unsatisfied 50 0 100 200 300 400 500 600 700 Mouth to ear delay in ms 5 VoIP Simulation Methodology and Setup Link Level System VoIP Simulator Simulator Capacity Standard Channel Noise Scheduler Overhead Model §Capacity of a center cell studied that is embedded in a cluster of multiple rings of cells §COST231 propagation model used. The maximum path loss is assumed identical to that of 3G1x §Users are assumed uniformly distributed in the system. The average number of users in each sector is the same while the instantaneous users vary according to a Poisson process §Terminals assumed to have dual receive antennas 6 User Mobility and Fading Channel Profile •Mix of 3 types of channels: •Mix of mobile speed profile –AWGN –Stationary –1 path-Rayleigh –3 km/h (pedestrian) –2-path Rayleigh –30 km/h (street) –100 km/h (highway) 25% 15% 30% 25% 12.5% 10% 20% 7.5% 2-path- Suburban 10% 5% 0% 1-path - Suburban 0 kmph 3 kmph AWGN - All Morphologies 30 kmph Mobile speed 100 kmph 7 RL Packet Delay Distribution (DO Rev. A) 100% • Frame alignment delay is included No frame in this distribution concatenation • 90% of packets are delivered Percentage of packets 90% within 45 ms • 98% of packets are delivered in 80% 60 ms • Almost all packets are delivered 70% within 70 ms • The delay is limited to about 70 ms by design 60% 35 Erlangs Theory 50% 20 30 40 50 60 70 80 Air Interface Delay in ms 8 RoT of RL (DO Rev. A) 100% •The rise over thermal (RoT) at the base station is shown in the left chart. 90% The average of RoT is: 80% 26 Erlangs –About 3.2 dB with 26 Erlangs Probability Distribution 70% –About 5.4 dB with 35 Erlangs 60% 35 Erlangs –About 9.1 dB with 40 Erlangs 50% •35 Erlangs can be supported with an 40% average RoT less than 5.5 dB 30% 20% 40 Erlangs 10% 0% 2 4 6 8 10 12 Rise Over Thermal in dB 9 FL Packet Delay Distributions (DO Rev. A) 100% • 50% packets in the system are delivered in 10 ms • 99% packets in the system can 90% meet 65 ms target when the load is 35 Erlangs Packet distribution 80% • Almost all packets (packets from 98% users) in the system can meet 95 ms target when the load 70% is 35 Erlangs 10 Erlang 20 Erlang 60% 30 Erlangs 35 Erlang 50% 0 10 20 30 40 50 60 Air Interface Delay in ms 10 Mobile to Land Delay Analysis (DO Rev. A) 35ms 70ms 10ms 10ms 8ms 7ms Air Air Interface Interface Base Station Backhaul RNC PDSN Total Delay = 185* ms IP IP Network Network Class 5 MGW Switch & Local Loop 25ms 20 ms * IP Network delay is service provider dependent and needs to be added to this number 11 Land to Mobile Delay Analysis (DO Rev. A) IP IP Network Network Class 5 Switch & MGW PDSN RNC Backhaul Local Loop 20 ms 35ms 7ms 8ms 10ms Total Delay = 180* ms Air Air Interface Interface Base Station 5ms 95 ms 25ms * IP Network delay is service provider dependent and needs to be added to this number 12 Beyond the Air Interface Lucent Technologies What is Carrier Grade VoIP? • The Case for Core Migration (TrFO/RTO) is Clear – Driven by cost reduction (specifically vocoders) – But reduced cost is not enough • The Big Question: “Cost considerations aside, what characteristics would a network have to demonstrate in order for you to migrate your voice network to VoIP on EV-DO Rev A?” • What we’ve heard from our customers: – The VoIP network must enable new revenue opportunities – The VoIP network must enable a rich set of simultaneous voice, data and multimedia applications to compete with UMTS/HSDPA – The VoIP network must provide equivalent voice quality and delay to today’s circuit switched voice network. – The VoIP network must provide seamless mobility equivalent to that provided by today’s circuit switched voice network. – The VoIP network must provide the same opportunities for differentiation on price, performance and service bundling that are enabled by today's circuit voice networks. – The VoIP network's performance must be capable of being measured and adjusted with the same level of control enjoyed in today's circuit voice networks. 14 Specific Requirements for Carrier-Grade VoIP (1) • Performance – Call completion rates, call setup time, call drop rates equivalent to circuit voice network – Voice quality and delay equivalent to circuit voice – Capacity at least as high as circuit voice – Seamless mobility (intra and inter-vendor) • Reliability & Availability – Network reliability and availability must be equivalent to CS network (five nines) – Not clear that this applies at the component level for the bearer and signaling path (service level may be sufficient) • However, a mechanism for preserving call states and billing information at five nines reliability is required • Other components (subscriber databases, etc) still require five nines component reliability • Traffic measurement/control – Must be able to identify packet traffic by user and by application and bill appropriately in order to be able to continue to compete via pricing plans, service bundles, etc. • Inter-vendor issues? 15 Specific Requirements for Carrier-Grade VoIP (2) • Network Configuration, Management, Provisioning, Monitoring – Wherever possible, each component and subsystem needs to generate appropriate service measurements and provide a means to adjust performance – However, must be able to assess and adjust end-to-end network and sub- system performance in a multi-vendor environment, where some elements do not generate appropriate measurements – Need appropriate OA&M and OSSs that provide the same level of control enjoyed on the CS network • Service Parity/User Transparency – The network should provide a key subset of the same set of services provided by the current CS network – The end-user should be able to access user services in the same way he does today • Security – Wireless packet networks are vulnerable to the same sorts of attacks as wireline packet networks, as well as wireless-specific threats • Need a robust set of wireless-specific defenses 16 Specific Requirements for Carrier-Grade VoIP (3) • Mobility Management – Mobility within and across vendor boundaries should perform at a level equivalent to 1x CS voice networks • DSC channel and new FL handoff mechanisms enable seamless mobility across base stations on the same RNC • Proprietary mechanisms to facillitate seamless inter-RNC mobility exist (e.g. Lucent) – Inter-vendor RNC handoff issues are being addressed in standards (IS- 878B, due mid ’06) » Will also address hand-down to 1x – What are the requirements? • For hand-down to 1x? • Across air-interface technologies? 17 Availability of Features in VoIP via IMS • CDMA VoIP coupled with an IMS core network enables the introduction of new simultaneous voice, data & video services to CDMA users • IMS manages the interaction of multiple application servers to deliver blended voice, data & video services – IMS based centralized control provides a seamless user-experience when multiple application servers are involved – Per user subscription to features are provisioned in network – Traditional telephony features can be integrated with presence, location, messaging & video services • Traditional telephony features are also provided for VoIP users – Multiple TAS (Telephony Application Servers) are being integrated with IMS • Residential feature servers support subscriber features • Enterprise feature servers support PBX extension features – Key legacy CDMA features will be implemented on a TAS 18 Blended Services Enabled by VoIP & IMS • Access independent telephony services (includes IP-PBX, IP-Centrex, VoIP, VoWLAN features…) • Blended Services Building Blocks • Presence and location (including identity/ security / policy management functionality/subscriber data management) • Active Phonebook • Unified messaging (IM, PoC, short video service, multimedia video services and SIP- enabled messaging services) • Video communications (includes instant video messaging, video telephony, video conferencing 19 How do we get there from here? Lucent Technologies VoIP Migration Strategy • Ubiquitous DOrA VoIP coverage is optimum solution to provide ubiquitous simultaneous voice, data & video services. ü IMS infrastructure supports blended voice, data & video services. ü DOrA RAN supports increased voice capacity. • In areas where DOrA is not deployed, a software upgrade (terminal, BTS, RNC, PDSN) to 1X SO60 is recommended to support simultaneous voice & data services. ü 1X SO60 VoIP QoS, capacity & performance are analogous to 1X circuit voice. ü 1X SO60 coupled with IMS supports blended voice & low speed data services. ü Common IMS core ensures feature transparency during hand-offs. • In areas where neither DOrA or 1X SO60 are deployed, 1X circuit voice can be used to fill in the voice coverage gaps. ü Seamless handoff of basic voice call. ü On handoff to circuit voice, feature control is transferred to the circuit network. ü Handoff involves voice call only. • Interface legacy CDMA MSC back-office systems to IMS core for on-going revenue generation. ü Build SIP interfaces on legacy equipment. ü Support inter-working for critical revenue generating features (e.g. SMS, Prepay). 21 Circuit to Packet Network Evolution New Revenue Generating Service Voice on PCM, IMS services CDMA & applications VoIP/DO signaling Packetize High speed the core Packet data EV-DO network On EV-DO Rev A Grow network capacity & Cost Savings Packetize the core network (circuit voice on IP transport): • Packet tandem/gateway (IP core network between MSC’s) • IP interfaces and SIP signaling on FPS (Core700+PSU2e=FPS) – IPBackHaul, TrFO/RTO, IP SHO IMS services & applications (SIP endpoint signaling + VoIP applications): • Centralized servers, “coordinated” services • Simultaneous voice and data services • Access independent services network High speed data on EV-DO/DV (faster air interface and infrastructure): • Road warriors, extend the office • Video (streaming, on-demand, …) VoIP (QoS guarantee, data network with high reliability & low cost): • Voice as just another data application • More flexibility in capacity growth options 22 Summary/Conclusions • The move towards VoIP on EV-DO is being driven by – The enablement of new and blended multimedia services (i.e. new revenue opportunities) – Cost reduction (enhanced air link capacity, all-IP core, etc.) • A number of basic requirements must be met before VoIP on EV- DO can replace circuit voice as the primary voice service – Some of these have been or are currently being addressed in standards (QoS, mobility, hand-down, etc.) – IMS offers a lot of solutions – Are there still holes? • How do we get there from here? – Dealing with legacy and transition. – Trade-offs 23
Pages to are hidden for
"Carrier Grade VoIP on EV-DO Rev A"Please download to view full document