1. IEEE 802.21 MEDIA INDEPENDENT HANDOVER
DCN:
Title: IEEE Operation with Proxy Mobile IP
Date Submitted: January 20, 2009
Presented at IEEE session #30 in Los Angeles
Authors or Source(s):
 Christian Mayaka, Ashutosh Dutta and Subir Das
Telcordia Technologies Inc.
Abstract:
This presentation describes how services can be used in handover scenarios where PMIP is used.

2. IEEE 802.21 presentation release statements
This document has been prepared to assist the IEEE 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
The contributor is familiar with IEEE patent policy, as stated in Section 6 of the IEEE-SA Standards Board bylaws < and in Understanding Patent Issues During IEEE Standards Development
IEEE presentation release statements
This document has been prepared to assist the IEEE 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
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

3. Introduction
PMIP has become a de-facto mobility management protocol in 3GPP (SAE/LTE) and Wi-MAX Forum (NWG)
We included PMIP call flow using IEEE in our specification (Appendix)
It’s time to look into the goals and issues of PMIP and in particular, how IEEE can help optimizing the seamless handover in different scenarios
IETF has currently defined PMIP for single interface handover
New discussions has started for dual-interface and support for multi-homing

4. Proxy Mobile IPv6 Basics
LMA: Local Mobility Anchor
MAG: Mobile Access Gateway
Data communication
LMA Address (LMAA)
IP Tunnel
Data communication
Proxy Binding Update
(Obtain IP#1)
Proxy-CoA
IP address allocation
(IP#1)
Network attachment and access authentication MN
（IP#1） MN
（IP#1）
Handoff

5. Goals for PMIP Handover Performance Improvement
Reduction in Handover-Related Signaling Volume
Location Privacy
Limit Overhead in the Network
Simplify Mobile Node Mobility Management Security by Deriving from IP Network Access and/or IP Movement Detection Security
Link Technology Agnostic
Support for Unmodified Mobile Nodes
Support for IPv4 and IPv6
Reuse of Existing Protocols Where Sensible
Localized Mobility Management Independent of Global Mobility Management
Configurable Data Plane Forwarding between Local Mobility Anchor and Mobile Access Gateway

6. Use Case Scenario- Single Interface
Core Network
LMA
AAA
Server
Access Network
Access Network
Access GW1/MAG1
Access GW2/MAG2
AP/BS
AP/BS
IF1 MS

7. How IEEE Can Help?
To allow MAGs to set correctly the HI and ATT values in PBU
Link layer information via Link_Detected_Indication primitive
MN’s context transfer (QoS and Authentication) and to set tunnel between pMAG and nMAG
Use of MIH_N2N_HO_Commit primitive
Packets are forwarded from pMAG towards nMAG
MIH_Link_Going_Down primitive triggers pMAG
MAG needs to know if the handover is an intra and inter-technology handover or not
Link_Detected_Indication primitive and IE_Network_Type can provide such information

8. Single Interface Use Case +IEEE 802.21
Core Network
LMA
AAA
Server
Access GW1/MAG1
Access GW2/MAG1
PoS1
PoS2
PoA2
PoA1
IF1 MS

9. Use Case Scenario- Dual Interface
Wi-Fi and WiMAX Scenario
Connectivity Service Network (CSN)
LMA
AAA
Server
Access Network (Wi-Fi)
Access Service Network (Wi-MAX)
ASN-GW/MAG1
AR/MAG2 AP AP BS BS
IF1
IF2 MS

10. PMIP Issues in Dual-Interface Case
LMA must assign the same HNP existing in BCE for seamless IP sessions transfer from IF1 to IF2.
LMA may assign the same HNP only if HI is correctly set in PBU.
It depends upon lower layer information
If MN receives a new prefix and configures a new address for IF2, IP sessions transfer is not possible with normal IP stack
If nMAG sends PBU earlier and BCE is updated before MN releases connectivity with pMAG, LMA will drop uplink packets from pMAG
Packets forwarded by LMA to nMAG may be lost due to buffer overflows

11. How Can Help?
To allow MAG to set correctly the HI and ATT value in PBU
Link layer information can be obtained Link_Up event
To let MAG know that MN will retain the same IP address for the new interface
Use of IPRenewalFlag of MIH_Link_Up event
MN’s context transfer (QoS and Authentication) and to set tunnel between pMAG and nMAG
Use of MIH_N2N_HO_Commit primitive
Packets are forwarded from pMAG towards nMAG
Use of MIH_Link_Down triggers
MAG needs to know if the handover is an intra and inter-technology handover or not
MIH_LINK_Up primitive and IE_Network_Type can provide such information

12. Dual Interface Use Case + IEEE 802.21
Wi-Fi and WiMAX Scenario
Connectivity Service Network (CSN)
LMA
AAA
Server
AR/MAG2
ASN-GW/MAG1
PoS1
PoS2 AP AP BS BS
PoA3
PoA4
PoA1
PoA2
IF1
IF2 MS

13. Use of PMIP in Multi-homing
Base PMIP RFC covers only simultaneous connectivity using the multi-interface case
For example, IF1 is connected to WiFi and IF2 is connected to WiMAX
As long as the interface connection does not change, handover does not arise
Similar to using PMIP for boot-strapping case
Support of Multi-homing in PMIP is based on two simple models:
Model 1: Unique prefix assigned to each interface of MN
Model 2: Same prefix used for all interfaces of MN
However, these two models lack multi-homing features:
Simultaneous Usage Support
Flow Filtering Support
Operation complexity at LMA/HA to support unique prefix per interface allocation

14. Multi-Interface Scenarios
Unique Prefix per Interface
Each interface is assigned a unique prefix
LMA maintains multiple binding cache entries
One entry per interface
May contain layer 2 interface identifier and access technology type
Unique Address per Interface
Assigned the same prefix across multiple interfaces, but unique address per interface
LMA maintains separate binding cache
Separate BCE but separate host route entry per address
Shared Address across Interface
Assigns the same address across multiple interfaces
Make only one IP address visible to the application
Use of flow information, Service Selection Option in the Proxy Binding Update

15. Requirements for Handover across Interfaces
Important to note that multi-interface requirements are valid for both intra-access and inter-access handover
Removal of IP address/prefix from old Interface
Needs Link tear down
IEEE can help here
Configuration of same IP address/prefix on the new interface
Stateless auto-configuration may not guarantee this through only RA prefix as the MN interface ID changes
Thus it needs new mechanism and an opportunity for IEEE
One Interface active at a time
Interface Identifier Option is sent as part of the PBU which tells LMA that the MN is using a different type of interface
An opportunity for IEEE to provide this info