1. 21-07-0274-00-0000_3gpp_inter-tech_handover IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-07-0274-00-0000 Title: Considerations for 3GPP/non-3GPP Handover Using 802.21 Date Submitted: July 2007 Present at IEEE 802.21 session #21 in San Francisco Authors or Source(s): Paul Flynn, Qiaobing Xie Abstract: This document discusses the considerations of using 802.21 for low latency 3GPP/non-3GPP handover.

2. 21-07-0274-00-0000_3gpp_inter-tech_handover IEEE 802.21 presentation release statements This document has been prepared to assist the IEEE 802.21 Working Group. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.21. The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/guide.html> Section 6.3 of the IEEE-SA Standards Board Operations Manualhttp://standards.ieee.org/guides/opman/sect6.html#6.3 http://standards.ieee.org/board/pat/guide.html

3. 21-07-0274-00-0000_3gpp_inter-tech_handover General Considerations Handover should be mobile-assisted –Mobile-assisted in terms of mobile sending measurement reports of both 3GPP and non-3GPP interfaces to the network Handover should be network-controlled –3GPP operators tend to want predictability e.g., they want consistency and predictability in handover decision for a given set of radio conditions –Operators typically set Key Performance Indicators (KPIs) for handover performance, needing tight control over meeting them Inter-technology handover decision function belongs in the RAN (eNB) –It will be in the eNB for intra-LTE handover –Following the approach for 3GPP 2G/3G handover, it will be in the eNB for 3GPP inter-RAT handover –Handover decision for intra-LTE, inter-RAT (but still within 3GPP), and inter- technology should be integrated, not distributed across network elements Inter-technology handover should be a prepared handover to minimize interruption time (e.g., pre-configured, resources pre-allocated) –Interface in the style of S3 from the MME to a peer in the other technology

4. 21-07-0274-00-0000_3gpp_inter-tech_handover MIH Information Server Considerations Info Server should be accessible from the handover decision function in eNB Should the Info Server have an O&M interface? –Initially inter-technology neighbor list info in 3GPP would be fairly static –Already used to configure similar neighbor list type of info into internal eNB database Should MIH Info Server query be part of handover call processing? –For example: If neighbor list determination needs to be based on a finely grained UE location How does MIH Information Server based approach compare with discussions in 3GPP RAN and SA5 about avoiding the need to construct neighbor lists (something like self-organizing networks has been discussed)?

5. 21-07-0274-00-0000_3gpp_inter-tech_handover Areas for Initial 3GPP Insertion The definition of an 802.21 based S3-Like Interface: Use the MIH_N2N_HO_* messages in MIH Command Service –It would be great to introduce these as a common interface for supporting inter-tech handover between 3GPP-3GPP2 and 3GPP- WiMAX The definition of an 802.21 based interface from the eNB to the MIH Info Service for accessing the neighbor information service Use MIH Event Service for measurement reporting from the mobile on its WiMAX air interface. Use MIH Command Service between the multi-modal mobile and 3GPP network for handover execution

6. 21-07-0274-00-0000_3gpp_inter-tech_handover Areas Where Native Mechanisms Should be Used For handover execution 3GPP and 3GPP2 layer 2 messages should be used between the mobile and network Use layer 2 techniques such as RRC System Information to convey neighbor lists to the mobile when it is camped on 3GPP radio access technologies

7. 21-07-0274-00-0000_3gpp_inter-tech_handover Location of 802.21 Functions Handover Decision Function Handover Info Server To eNB and Handover Decision Function in non-3GPP Access Technologies S3 style interface to non-3GPP Access Technologies Handover Decision Function