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VoFi standards & deployment models. Thenu Kittappa. Agenda. Trends in VoWLAN VoWLAN standards What makes a good VoWLAN handset? Different deployment models for Voice over Wi-Fi, single-mode & FMC. VoWLAN trends 2005-07. WMM-SA?. Fixed-Mobile Systems with handover. Fixed-Mobile Systems
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VoFi standards & deployment models Thenu Kittappa
Agenda • Trends in VoWLAN • VoWLAN standards • What makes a good VoWLAN handset? • Different deployment models for Voice over Wi-Fi, single-mode & FMC
VoWLAN trends 2005-07 WMM-SA? Fixed-Mobile Systems with handover Fixed-Mobile Systems Single-number with no handover 802.11e in CE Any SIP VoWLAN handset with any SIP PBX VoIP SIP handsets Large SIP PBX Small SIP PBX SIP (IETF) FMC Operators WMM handsets WMM infra FMC Gateways 802.11 WFA QoS SVP FMCA PRD III (IMS) FMCA MobileIGNITE UMA VCC FMC FMCA PRD II (SIP) FMCA PRD I (UMA) Q3 05 Q4 05 Q1 06 Q2 06 Later Q3 06 Later Q4 06
Enterprise VoWLAN interfaces Voice Telephony Gateway • WLAN to PBX interface • Emergency call handling • Location • SLA indications • Troubleshooting tools SIP PBX Or softswitch • Handset to PBX interface • SIP • SIP++ • Presence • Emergency calls • WLAN • QoS • Seamless coverage • Interference detection • Management tools • Troubleshooting tools • WLAN to Handset interface • Fast handover • Good QoS • Call Admissions Control • Good battery life • Public access & emergency
Current 802.11 standards • Standards activity relevant to voice • .11i (MAC Security Enhancements) / WPA • All phones will become better at authentication, encryption, by implementing WPA, WPA2… • .11e (MAC Enhancements, QoS) / WMM • Phases: WMM, APSD, TSpec sig, WMM-SA improve QoS, battery life • .11k (Radio Resource Measurement) • Assistance for handoff: opportunistic key caching with knowledge of key scope • .11r (Fast Roaming) • Aimed at improving secure handoff speeds. Not necessary when .11k neighbor report is used in conjunction with centralized encryption
1 2 3 4 5 Scale of excellence How complete is standards support? QoS Jitter Latency Packet errors/ drops (Over wired and wireless) CAC Handover Control/influence decision Speed of handover Security of handover Sleep Control: battery life U-APSD S-APSD Other features CALEA E911 Coverage WMM-SA WMM functionality WMM-SA Other 802.11 functionality Centralized architecture & vendor-specific features 802.11k 802.11k 802.11r 802.11r 802.11h 802.11h
Deployment of Voice in the Mobile Network Corporate IP PBX • VoIP allows a phone to receive corporate dialtone over the Internet • Incoming, outgoing numbers as PBX extension • Wireless VoIP is more secure than wired VoIP • Wireless requires less reprogramming than wired VoIP (no reconfiguration of AP or handset) Internet LAN WAN Main location Branch office Home office Hotel room
Enterprise VoWLAN Deployment Models • PBX Extension Mode: Wireless phone is configured as an extension on the PBX Internet Voice Telephony Gateway • Pros • Easy to configure on the WLAN and the IP-PBX • SIP support on single-mode VoFi phones and IP-PBX allows best-of-breed mix & match • Phone automatically participates in Enterprise numbering plan (4-, 5-digit) and least-cost routing for long-distance calling SIP PBX Or softswitch LAN core • Cons • Existing PBX may need upgrading to support SIP extensions • All configuration falls on the Enteprise IT group (or outsourcer) • Single-mode phones will work on Enterprise Wi-Fi network & home locations, but not outside this coverage • Configuration complexity when users roam between sites (unless already covered by a unified PBX network) LAN edge
Enterprise VoWLAN Deployment Models SIP PBX Or softswitch • Hosted Mode: All call control is from the Internet Internet • Pros • No end-user configuration • Works with VoIP wired and single-mode wireless phones • Easy to upgrade to a fixed-mobile service (upgrade by the SP) • Easily integrated by the SP with long-distance & international VoIP plans LAN core • Cons • Survivability (loss of WAN = loss of service) • QoS (may require a guaranteed-QoS Internet/VPN service) • Single-mode phones will work on Enterprise Wi-Fi network & home locations, but not outside this coverage LAN edge
Enterprise FMC Deployment Models SIP PBX Or softswitch Cellular Core • Hosted Mode: VoFi side of the phone is homed to the hosted FMC Gateway • Cellular operator (SP) ‘owns’ the phone number and behaviour • User experience is closer to cellphone whether in or out of Wi-Fi coverage Internet FMC Gateway • Pros • No configuration by the IT group (except for access, see below) • Standards support for this model will ensure good pricing and availability of phones (eventually) • Easy inter-site roaming • Easily extended to commercial hotspots by SP roaming agreemeents LAN core LAN edge • Cons • Configuration of SSIDs, NAT, firewall may be a problem • Access by the SP for troubleshooting may require special firewall, demarc considerations • All calls are seen and possibly charged by the SP Cellular Base Station
Enterprise FMC Deployment Models Cellular Core • PBX Extension Mode: VoFi side of the phone is homed to the PBX • PBX forwards calls to the cellular number when phone is out of Wi-Fi coverage • Sometimes works with cellular data channel for presence & signalling when in cellular coverage • User experience is closer to PBX extension whether inside or outside Wi-Fi coverage Internet Voice Telephony Gateway • Pros • Can be configured by the IT group • Major PBX vendors are adding this functionality • Integrates with PBX numbering plan & features LAN core SIP PBX Or softswitch • Cons • Configuration burden falls on the IT group • All calls are anchored on the PBX • No standards, so phones will need custom code updates • Inter-site roaming needs to be carefully configured LAN edge Cellular Base Station