1. IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-09-0118-00-0000 Title: Issues with 802.21-2008 Date Submitted: July, 2009 Presented at IEEE 802.21 Session #33 Authors or Source(s): Vivek Gupta Abstract: Issues with 802.21-2008

2. 2 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. 3 802.21-2008 Issues

4. 802.21 Overview Defines 3 services  Event Services detects events and delivers triggers from both local as well as remote interfaces (i.e. between terminal and network)  Command Service provides a set of commands for the MIH users to control handover  Information Service provides the information model and an information server to make more effective handover decisions. The mobile terminal obtains information from the repository using its current network point of attachment or the target point of attachment

5. Issues with 802.21-2008 Existing and emerging cellular systems (WiMAX, 3G, 2G) already have these service concepts defined 802.21-2008 does not address service continuity during handovers 802.21-2008 just focuses on switching between radios Network Discovery and Selection is main focus Not viable since ND&S is not a big issue in licensed bands 802.21-2008 does not address Single Radio Handovers

6. Issues with 802.21-2008 Event Service Limited utility of remote events Refer to Aboba draft Individual MACs already define most of MIH Events Link_Detected, Link_Up, Link_Down, etc. MIH Events don’t have any specific MAC connotation How to implement Link_Going_Down? Measurement Reporting (for network-initiated handover) MS reports its radio measurements to the network This can be avoided since the MS can make decision for handover So why care about MIH_Link_Parameters_Report ?

7. Issues with 802.21-2008 Command Service MIH_MN_xxx, MIH_Net_xxx, MIH_N2N_xxx Handle Client<>Network Co-ordination Help with switching radios for dual radio handovers Not very useful in practice Network policies typically uploaded on client devices Client makes HO decisions based on policies No Client<>Network co-ordination required MIH_MN_xxx, MIH_Net_xxx, MIH_N2N_xxx Not required for dual radio handovers

8. Issues with 802.21-2008 Information Service 3GPP has decided to use OMA for ANDSF 802.11 planning to use native GAS mechanism 802.21 IS and RDF Complicated and difficult to use Value add not very clear and no SDO is adopting this!

9. 9 How to Fix 802.21-2008

10. MS 3GPP Network Interne t WiMAX Network Dual Radio Handovers 3 4 BS ASN GW eNB 3GPP EPC 2 1 Both Radios are connected to network at the same time The platform needs to support simultaneous Tx/Rx MS uses target radio to prepare resources in target network Dual radio handovers lead to: Interference when radios are in close proximity in IMT-2000 bands Higher cost due to need for RF isolation, sharper filtering or active cancellation Complexity in platform design eNB: eNodeB BS: Base Station EPC: Evolved Packet Core ASN: Access Service Network GW: Gateway MS: Mobile Station

11. MS 3GPP Network Interne t WiMAX Network Single Radio Handovers 4 5 BS ASN GW eNB 3GPP EPC 2 1 Only one radio is connected to network at any time Only one radio is Tx at a time MS uses source radio to prepare resources in target network In Single radio handovers: A L2/L3 tunnel is established between source and target network MS uses L3 tunnel for resource reservation and authentication in target network MS establishes Network and Security context in target network MS powers down the source radio and powers up the target radio and does ranging on target radio to connect to target network 3 Inter-System Tunnel b/w Networks SRS SRS: Single Radio Server

12. 1. DL channel acquisition, MAC Synchronization (DL-MAP) 2. Initial ranging & PHY adjustment. RNG_REQ/RSP messages 3. Negotiation of basic capabilities SBC_REQ/RSP messages 4. PKMv2 MS Authentication & Authorization PKM_REQ/RSP 5. Registration (REG_REQ/RSP) Messages 6. Transport Connection Establishment DSA_REQ/RSP/ACK 7. IP Address Allocation (DHCP) WiMAX Single Radio Handover Messages Mobile Station WiMAX Network Messages over air-interface for initial network entry for WiMAX IP Tunnel Source Network Single Radio Server Target Network MS N/W Entry Messages over L3 Tunnel for Single Radio HO from 3GPP to WiMAX

13. Dual Radio Handover Procedure UE/ MS Source Access Target Access Information Repository HA 7. Inter-system Handover Procedure (Dual/Single radio Handover) 1. Data Traffic through Source Access Network AAA 6. Target RAT Selection and HO Decision 2. Target RAT System Information Broadcast 3. Policy and Target RAT Information Query/Response 4. Turn on Target-RAT(s) radio. Inter-RAT scanning N/W Mobility Manager 5. Target RAT-Measurement Reporting (Optional) 8. Target RAT Network Entry Procedure 12. Data Traffic through Target Access Network 9. Switch Radio Trigger 10. Mobility Protocol Binding Update 11. UE/MS IP Address Resolution Network Discovery & Selection Dual Radio Handover Procedure

14. 14 802.21 Handovers Define Single Radio Handovers WiMAX<>3G (Use L3 tunneling) WiMAX<>WiFi (Use L3/L2 tunneling) Use 802.21 MIH Protocol for tunneling MAC messages L2 Inter-RAT Information Broadcast Define small subset of information that can be broadcast at L2 Define IS at L3 Small subset of info could be used by WMF Under discussion Measurements Define a single report for WiFi-WiMAX Use 3G Report format for 3GPP measurement reporting

15. Optimized Handover between different technologies IEEE 802.21-2008, Published in Jan-2009 Security Signaling during Handovers IEEE 802.21a, PAR Approved in Dec-2008 Handovers to Broadcast Technologies IEEE 802.21b, PAR Approved in Jan-2009 Emergency Services in 802 networks IEEE 802.21.1, PAR under development Battery Power Conservation in Multi-Radio devices IEEE 802.21c, PAR under development Progression towards Media Independent Services IEEE 802.21 Revision PAR under development 802.21 Evolution Multi-Radio Activities in IEEE 802.21

16. 16 802.21 Next Steps WG already planning on doing things beyond Handovers Multi-radio (Media independent) services Need to change Title and Scope of WG Members not happy when name Media Independent Handoff appears on cover page of subsequent specifications (ES) Constantly asked by 802EC why are we doing things beyond handovers Revision PAR allows us to change Title and Scope of WG 21-0075-01-0000