VoIP in the Wireless World

Aarti Iyengar
Product Specialist, Nortel
aarti@nortel.com


July 2005, Sanog 6           -1
Agenda

• Issues
• Standards and Market Evolution
• IP Multimedia Services
   — Architecture
   — Applications and Challen...
Interactive Wireless voice quality: Main
Issues
                                                                          ...
Interactive Wireless Voice Quality: Issues
• Packet Loss                     • Effect of IP headers
  — Moderate losses (1...
Can we do efficient signaling?
Wireless VoIP => Mobility

 • Classic telephony approach:
    — HLR (home) /VLR (visitor)
 ...
Standards and Market Evolution




        UMTS    CDMA                               WIMAX                               ...
Wireless Broadband – The New
Category
                                    Wireless Broadband
  Mobile

                   ...
Voice over WiFi / WiMax Voice possibilities
         •
Wireless — Complement/alternative to cellular in target areas unser...
VoIP over Wireless LAN/MAN: Challenges

           •   Cellular operators fear cannibalisation.
           •   Tier 1 hand...
VoIP over Cellular

            • Cellular evolution
               — CDMA 1xRTT -> EV-DO -> EV-DV
               — GSM/GP...
IP Multimedia Subsystem (IMS)
• 3GPP IMS Defined
• Standards-based Architecture for delivering ubiquitous multimedia servi...
IMS Network Elements
      Interrogating -- CSCF
       Interrogating CSCF
 ••Selects appropriate Serving-
   Selects appr...
The Service Centric Business Model
Building on the IMS Architecture
                                       Service Coverag...
IMS based architecture challenges
                                 Applications                App challenges
            ...
Wireless VoIP – End to End
   TrFO For Voice
   Quality On Calls
      Between
     MMD/IMS &                   A1 Interfa...
Looking ahead
  • VoIP will continue to be the key application driver over wireless
      networks – “Cash Cow”
  • Standa...
Thank you

Aarti Iyengar
Nortel
aarti@nortel.com


July 2005, Sanog 6   - 17
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Microsoft PowerPoint - WirelessVoIPSanog6_Aarti

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Microsoft PowerPoint - WirelessVoIPSanog6_Aarti

  1. 1. VoIP in the Wireless World Aarti Iyengar Product Specialist, Nortel aarti@nortel.com July 2005, Sanog 6 -1
  2. 2. Agenda • Issues • Standards and Market Evolution • IP Multimedia Services — Architecture — Applications and Challenges • Looking Ahead - Summary -2
  3. 3. Interactive Wireless voice quality: Main Issues value 5 10 20 30 40 60 0 200 400 600 0 200 400 600 • Delay — Coding, Jitter, Packetization, • Packetization Frequency Buffering, Propagation — Size => Delay => Quality — Wireless Voice is already at the upper edge of the delay curve! — Any shift in this equilibrium will make the quality unacceptable — Strongly influenced by wireless link -3
  4. 4. Interactive Wireless Voice Quality: Issues • Packet Loss • Effect of IP headers — Moderate losses (1%) can — Significant header be concealed. overhead — Higher losses require — Inefficient use of RF spectrum when redundancy (standard in transmitted over air RTP): interface – Affects bandwidth — Header compression – affects quality improves air interface — Packet loss strongly bandwidth influenced by wireless link • QoS — Manage uplink contention IP Hdr UDP Hdr RTP Hdr Payload 20 bytes 8 bytes 12 bytes 10-80 bytes — Real time voice has very stringent requirements -4
  5. 5. Can we do efficient signaling? Wireless VoIP => Mobility • Classic telephony approach: — HLR (home) /VLR (visitor) — Based on phone number — Number = User identity + Service Profile • VoIP separates network, service — Network: IP address — Service: DNS name, e-mail, URL • Need clean architecture — SIP provides end-to-end services oriented architecture -5
  6. 6. Standards and Market Evolution UMTS CDMA WIMAX wifi Used with the permission of the citizens committee to widen Highway 401 -6
  7. 7. Wireless Broadband – The New Category Wireless Broadband Mobile 3GPP Evol? UMTS Cellular HSDPA F-OFDM 1xEV-DO Local Area WiMAX 802.16e Cordless WiFi 802.11 n 802.11 a/b/g WiMAX 802.16d Fixed Wireless equivalent POTS for DSL/ Cable Voice & Messaging Broadband -7
  8. 8. Voice over WiFi / WiMax Voice possibilities • Wireless — Complement/alternative to cellular in target areas unserviced areas — Delivery of broadband voice and data services to (city HotZones) LAN/MAN – rural areas/towns, underprivileged areas & developing countries – Reduced communications cost for campus environments, — Specialized deployments (government/military deployments, emergency) • WiMax is gaining popularity — Not Mobile Voice: that’s Cellular – real time, ubiquitous, urgency-driven, life-line — Not Enterprise Mobility: that’s WiFi – bounded geography, best-effort, free (or nearly) — Emerging as high speed data access method, but service providers must bundle VoIP and other multimedia services to generate revenue • Small service providers have started implementing WiFi VoIP networks — Demand in Corporate networks, residential areas, public spaces. Widespread availability when WiMax is fully standardized -8
  9. 9. VoIP over Wireless LAN/MAN: Challenges • Cellular operators fear cannibalisation. • Tier 1 handset vendors fear alienating cellular operators. • Dual phone mode – WLAN and WAN (CDMA/GSM) coverage. — GSM/WLAN handover not yet a key industry priority — AND ….Some category of users don’t want to part with what they are used to – attachment to personal GSM/CDMA phones. Difficult forcing them to use another dual mode GSM/VoWLAN phones. Initial offerings may not be very seamless. • More elegant VoWLAN handsets coming onto the market (eg Hitachi) but not many colour screens. • Other major issues being sorted out — Security support (encryption , authentication) — Access point capacity limit, QoS for prioritization — Proximity to access point impacts actual bandwidth • Handset power management and battery life -9
  10. 10. VoIP over Cellular • Cellular evolution — CDMA 1xRTT -> EV-DO -> EV-DV — GSM/GPRS -> EDGE — and there is also UMTS • Cellular circuit based networks evolving to bearer independent core networks (BICN) with Call Server, Media Gateways and IP Voice Packet core (3GPP R4/R5/R6) • IOS 5.0 to support packetized interfaces on BSC — Can support end-to-end VoIP call • Transcoder Free Operation being standardized for end-to-end native wireless compressed VoIP call • IP Multimedia Subsystem (IMS) / Multi Media Domain (MMD) being standardized to define services framework - 10
  11. 11. IP Multimedia Subsystem (IMS) • 3GPP IMS Defined • Standards-based Architecture for delivering ubiquitous multimedia services • Initial release was for UMTS access, subsequently adopted by 3GPP2 for CDMA (MMD) • Subsequent releases support access independence Intranet/ Internet • Key benefits Packet Switched or —Standards-based services framework PS Domain —Scaleable and cost effective IP Multimedia —QoS framework Subsystem —Increased service innovation (IMS) —Decreased time-to-market for new service Circuit Switched or introduction CS Domain PSTN - 11
  12. 12. IMS Network Elements Interrogating -- CSCF Interrogating CSCF ••Selects appropriate Serving- Selects appropriate Serving- Application Home Subscriber Server Home Subscriber Server CSCF CSCF Servers ••New IP-centric subscriber New IP-centric subscriber ••Supports roaming & security Supports roaming & security data functions data functions Border Gateway Control ••Identity management Identity management Function ••Profile management Profile management Sh BGCF ISC Home HSS Subscriber Server Serving- CSCF Serving- CSCF Breakout GW Control Function Breakout GW Control Function Cx ••SIP Session Management SIP Session Management ••Selects the network & MGCF in Selects the network & MGCF in ••Interacts with Application Servers Interacts with Application Servers which PSTN interworking will which PSTN interworking will occur ••Authentication enforcement Authentication enforcement occur CSCF ••Billing Billing S I P Policy Decision MGCF Function Policy Decision Function Policy Decision Function Call Session PDF ••Session gating Session gating Control Function ••Session based QoS Session based QoS Media GW Control Function Media GW Control Function Proxy -- CSCF Proxy CSCF ••Correlated Charging Correlated Charging ••Provides inter-working between SIP in Provides inter-working between SIP in •• Manages QoS Manages QoS IMS/MMD and ISUP in PSTN/PLMN IMS/MMD and ISUP in PSTN/PLMN ••Generates billing Generates billing ••Manages Media Gateways using H.248 Manages Media Gateways using H.248 ••Handles local services (e.g. 911) Handles local services (e.g. 911) - 12
  13. 13. The Service Centric Business Model Building on the IMS Architecture Service Coverage Multi-Device features Multi-Access —Services adapted to — Interaction between a various device Handset variety of access types requirements UM — Simultaneous and/or —User selects most A sequential use of variety of DM TS one appropriate device C Video devices k ph PC depending on location ing Multimedia Des IM and service Gam Voice —Add video, images, G PR LAN Pr at a es en audio, and various S D ce media formats —Mix and Match Voice pt op WLAN A PD applications — “Cash Cow” for La Wireless —Presence & messaging can lead into a voice/ — Next generation Service Innovation video session services must build on and extend voice features —Peer-to-peer: new delivery aspect IMS delivers the basic service centric framework. Easy to deliver DIFFERENTIATION! - 13
  14. 14. IMS based architecture challenges Applications App challenges • Support the widest range of apps • Enable third party development of apps • Make apps dynamic with network data End users • Facilitate integration between apps • Integrate legacy apps Core External End-user experience challenges networks • Provide a simple, integrated experience to the end-user • Support services on many access Interworking challenges types and clients • Create the largest community of • Co-exist with legacy applications users (PSTN, other PIM, other (CS voice, SMS, etc) IMS/MMD) • Facilitate IMS/MMD voice/video on wireless access Core challenges • Protect the network from abuse • Maintain high availability • Simplify & optimize the network • Offer flexible charging and policy - 14
  15. 15. Wireless VoIP – End to End TrFO For Voice Quality On Calls Between MMD/IMS & A1 Interface MGCF ISUP 1xRTT CDMA H.248 1xRTT Access H.248 MGW SIP HA BSC/RNC PDSN 16K MGW SIP CDMA PSTN 1xEVDO Access aTCA Application MGCF For Calls P/I/S-CSCF Servers Between MMD/IMS PDF, BGCF & Legacy PSTN - 15
  16. 16. Looking ahead • VoIP will continue to be the key application driver over wireless networks – “Cash Cow” • Standardization impacting PTT deployments and 3GPP IMS launches —End to end SIP-based IMS architecture being evaluated by wireless operators —PTT deployments across many Tier-1 Operators —IMS trials and limited deployment across several Tier-1 Operators • EDGE-EV DO-UMTS will increase focus towards multimedia hungry applications —Content partnerships gaining significance • VoIP will be key, with bundled service strategy —Video, PTT & Mobile Music services, bundled with VoIP for delivery • Video Telephony will be in great demand among consumers —Video as leading converged application with efforts to link fixed Video users to mobile video users • Evolution of Broadcast standards for Mobile TV implementations • MMS (including video attachments) starting to be used widely • SMS will continue to be important • Improvements to Handsets - IM as part of the wireless handset The next couple of years will be the years of Mass Market Wireless VoIP and Multimedia Applications - 16
  17. 17. Thank you Aarti Iyengar Nortel aarti@nortel.com July 2005, Sanog 6 - 17

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