-1- Layer 2 Mobility for Real Time Packet Data Service in All IP Network 3GPP2 All IP Ad Hoc Boulder, CO July 17~19, 2000 Jae-Young Ahn, Kyung-Sik Kim, Sang-Ho Choi Phone : ALLIP

-2- Background ▣ Motivation ◈ In current 3G cdma2000 Packet Data Service Reference Model(PN-4286), Data Link Layer(PPP or HDLC) should be reestablished in case of changing serving PDSN(Mobile-IP FA) –It results serious degradation or interruption of service ◈ TSG-P already suggested the need of simple link layer protocol with the following properties: (P , Qualcomm)  Simplicity in protocol and with minimal state  Improved data transparency (minimize byte escaping, bit stuffing, etc.)  Low header overhead on the transport  QoS support  Negotiation of compression (header and/or payload)  Protocol should be extensible ◈ As long as 3GPP2 All IP is highly related to PN-4286, All IP AdHoc is also required to investigate the feasibility of new link layer protocol improving L2 mobility not in PN-4286, but in All IP Network

-3- L2 Mobility in All IP MM domain ▣ PS domain in All IP Network experiences more serious problems on L2 Mobility because of temporal attribute of multimedia service ◈ Serious burst data loss in case of time-sensitive application(e.g. packetized Video or Voice) ◈ Resource waste due to retransmission and large buffer due to congestion In case of Best-effort Application (e.g. simple data ) ▣ No Contribution about Layer 2 (L2) mobility in All IP AdHoc ▣ L3 Mobility could be deleted or restructured because of its potential redundancy between L2 and L7 mobility ◈ L2 is becoming a bottleneck in view of handoff performance ▣ Focusing on L2 Mobility concerned with All-IP Requirements ◈ Use of PPP in All IP network protocol based on current 3GPP2 All IP NAM is to be problematic along with the progress of All IP standardization ◈ Specially unsatisfied results on Editor’s Accepted(Revised) Requirement Items in case of handoff (e.g. No interruption of service, etc.)

-4- Possible types of MS in All IP Network ▣ Assume that there are: ◈ Type 0 MS –2G cdma MS ◈ Type I MS –3G cdma2000 MS  CS Voice and Image  PS Packet Multimedia Data( Packetized voice, image and data) ◈ Type II MS –Pure All IP Multimedia MS (Wireless SIP or H.323 VoIP)  PS Multimedia data(Packetized Voice, Image and Data) => RTP/UDP/IP

-5- L2 Mobility of MS Type I ▣ Use of PPP for link layer between MS and PDSN ◈ In hand-off between PDSNs, require PPP reestablishment ◈ Real time packet data => Intolerable data loss –In Current cdma2000 System for packet data => No solution ◈ Best-effort Application => Needs retransmission and sufficient buffer ◈ Complex Header Compression due to PPP frame format and Various RLP Instances ▣ Evaluation ◈ Insufficient capacity for Real-time Multimedia services –Only usable for simple packet data service ◈ Only one detour depending on PDSN coverage planing –PDSN capacity is to be the major hurdle –Depending on operator’s policy

-6- L2 Mobility for MS Type II ▣ Upgrade of link layer protocol means a room for upgrading L2 Mobility for All IP ▣ Use of PPP for All IP Network means the easy migration from 3G legacy network but the same problems are remained ▣ Improve of L2 Mobility by using non-PPP protocol is required to support real-time multimedia service ◈ Advantage –Possible smooth and fast handoff for real time packet data ◈ Disadvantage –It may need the modification of the air interface protocols –It may need authentication procedure instead of CHAP extension –It may need modification of TR45.6 functions –Needs the increased cost for evolution

-7- Smooth Handoff Aspect on Type II MSs ▣ Using PPP ◈ Need of MS which can control multiple PPP session for the support of function similar to soft handoff ◈ Need of the solution for complex header compression ▣ Using non-PPP ◈ Need of new protocol for Type II MS and network entities ◈ Need of new solution for loose header compression

-8- Conclusion ▣ Justification ◈ upgrading L2 mobility results improvement of handoff performance consistent with Lucent contribution (ALLIP ) “requirement sec Mobility Management” –(e.g. Access Network Mobility with no service interruption) ◈ In order to support real-time service in All IP, L2 Mobility protocol should me improved as well as L7 and L3 Mobility management –L3 MM functionality can be controlled in conjunction L2 upgrade, since L3 MM has potential redundancy in IP MM domain ▣ Conditions for further improvement ◈ Handoff performance of the new protocol for L2 mobility should be enough to support QoS requirement for real time service including packetized video and voice ◈ Reliability for real time packet data is to be improved as well

-9- Suggestions ▣ CRs to 3GPP2 All IP Ad Hoc Requirement v0.4.0 ◈ In section 6.2.1, add item b)” The all-IP network IP MM domain should support link layer handoff for real-time multimedia, in a way of maximizing handoff performance ◈ In section 6.3.4, correct item d)”The All IP Network IP Multimedia domain shall support hard handoff between two RANs of the same technology, by means of L2 mobility ◈ In section 6.3.4, add item e)” Handoff performance of L2 mobility should be enough to support QoS requirement for real time service including packetized video and voice ▣ Suggestions on 3GPP2 All IP Ad Hoc NAM ◈ NAM is to be prepared in a way of supporting improved L2 mobility (Possibly in regarding of restructuring the duplication of L2/L3 Mobility Management) for real time packet data service