VoIP over 1xEV-DO CDG Technology Forum on VoIP November 5, 2004 Page 1
Outline VoIP over 1xEV-DO Performance Capacity & Latency System Considerations QoS CDMA2000 1X Compatibility Header Compression Summary Page 2
Voice over IP over 1xEV-DO RN IP RNC PDSN Core Network RN IP RNC PDSN Soft Switch MGW PSTN Page 3
Voice Quality vs. Delay (ITU-T G.114) 1X M-to-M < 280 ms CDMA2000 1X mobile-to-mobile latency: ~ 280 ms Page 4
VoIP over 1xEV-DO Capacity Page 5
VoIP Assumptions Variable-rate EVRC 1/8 th rate frames are blanked 1 RTP/UDP/IP packet per voice frame (no bundling) ROHC Header Compression 2 byte overhead per VoIP packet Page 6
Mobile-to-Mobile Latency Breakdown Vocoder DO Modem RL Delay Jitter 35 ms 5 ms Handset 120 ms + FL Delay Jitter + RL Delay Jitter + De-jitter Delay DO RAN + PDSN 20 ms 15 ms Engineered IP Network Vocoder De-jitter buffer DO Modem 20 ms 5 ms Handset FL Delay Jitter DO RAN + PDSN 20 ms Target End-to-End FER = 3% (RF packet errors + Packet drop in de-jitter buffer) Page 7
Mobile-to-Landline Latency Breakdown Vocoder DO Modem 35 ms 5 ms Handset RL Delay Jitter 110 ms + RL Delay Jitter + De-jitter Delay DO RAN + PDSN 20 ms 15 ms Engineered IP Network PSTN 20 ms MGW 15 ms Target End-to-End FER = 2% Page 8
Landline-to-Mobile Latency Breakdown Vocoder De-jitter buffer DO Modem 20 ms 5 ms FL Delay Jitter DO RAN + PDSN 20 ms Handset 115 ms + FL Delay Jitter + De-jitter Delay 15 ms Engineered IP Network PSTN MGW 20 ms 35 ms Target End-to-End FER = 2% Page 9
Airlink Simulation Assumptions 19 3-sector cells 3GPP2 channel model and evaluation methodology Users randomly distributed in the coverage area 3GPP2 mixed speed distribution 2 km cell-to-cell distance with 138 db max path loss All neighbor sectors generate forward link interference 100% of the time (conservative) All key Rev A features simulated Multi-user packets, QoS scheduler, H-ARQ, D-ARQ, etc. Page 10
Mobile-to-Mobile Call Latency (1 AT Ant) 100% 90% Percentage of Users with Latency < X 80% 70% 60% 50% 40% 30% 20% 20 Erlangs 30 Erlangs 40 Erlangs 10% 0% 180 200 220 240 260 280 300 320 End-to-end latency [msec] Target FER = 3% Page 11
Mobile-to-Mobile Call Latency (2 AT Ant) 100% 90% Percentage of Users with Latency < X 80% 70% 60% 50% 40% 30% 20% 20 Erlangs 30 Erlangs 40 Erlangs 10% 0% 180 190 200 210 220 230 240 End-to-end latency [msec] Target FER = 3% Page 12
Landline Call Latency (1 AT Antenna) 100% 90% Percentage of Users with Latency < X 80% 70% 60% 50% 40% 30% 20% 20 Erlangs 30 Erlangs 40 Erlangs 10% 0% 140 160 180 200 220 240 260 280 End-to-end latency [msec] Target FER = 2% Page 13
RL Rise-over-Thermal (ROT) Histogram 100% 90% 80% 70% CDF 60% 50% 40% 20 Erlangs 30 Erlangs 40 Erlangs 45 Erlangs 30% 20% 10% 0% 0 1 2 3 4 5 6 7 8 9 10 ROT [db] Less than 1% outage at 7 db at 40 Erlangs Page 14
Capacity and Latency Summary Latency at 40 Erlangs Load Coverage 98% 95% 90% M-to-M 1 ant 300 ms 280 ms 270 ms M-to-M 2 ant 230 ms 225 ms 220 ms Landline 1 ant 235 ms 220 ms 210 ms Landline 2 ant 185 ms 180 ms 180 ms Page 15
Other System Considerations Quality of Service CDMA2000 1X Compatibility Header Compression Page 16
Multi-Flow RLP for QoS Best Effort Flow 1xEV-DO RAN RLP NAK: Enable, DARQ: Disable, Scheduler: BE RLP NAK: Disable, DARQ: Enable, Scheduler: EF VoIP Flow Allows 1xEV-DO RAN to apply different treatment to VoIP flows Disables RLP NAK s and enables D-ARQ Applies priority scheduling Allows subscribers to use other applications while on a VoIP call Page 17
QoS Interfaces IS-835 835-D: QoS Signaling RN IP RNC PDSN Handset IS-856 856-A: Multi-flow RLP IS 878-A: A10/A11 Page 18
Key Performance Algorithms VoIP BE VoIP BE VoIP BE VoIP BE VoIP BE VoIP BE User Queues User # 1 User # 2 User # 3 User # 4 User # 5 User # 6 Scheduler Airlink scheduling Admission & overload control Fast sector switching Page 19
Compatibility with CDMA2000 1X CDMA2000 1X Region CDMA2000 1X & 1xEV-DO Region CDMA2000 1X Network Active Handoff CDMA2000 1X Network Interoperable 1xEV-DO Network CDMA2000 1X Phone 1xEV-DO VoIP Phone CDMA2000 1X Phone 1xEV-DO VoIP Phone Page 20
Header Compression RTP/UDP/IP header overhead is significant 40 bytes Voice payload at 8 kbps is only 20 bytes (20 ms frame) Candidate compression algorithms ROHC: reduces header to 1-2 bytes ecrtp: reduces header to 4 bytes Can be implemented in the PDSN or RNC With segment-based framing in Enhanced Multi-Flow Packet Application Page 21
Summary Evolution to VoIP is the next major transition in wireless networks 1xEV-DO Rev A is designed to carry data/voice traffic in all-ip format With a well-engineered IP core network, commercialgrade VoIP over 1xEV-DO Rev A is promising Call capacity greater than that of CDMA2000 1X is possible 2 antenna handsets may be required to maintain acceptable latency near cell edge at 40 Erlangs Page 22
Page 23 Thank You