Transcript 802.21 Next Steps

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
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802.21-2008 Issues
3
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
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
Issues with 802.21-2008
• Event Service
•
Limited utility of remote events
•
•
Individual MACs already define most of MIH Events
•
•
Link_Detected, Link_Up, Link_Down, etc.
MIH Events don’t have any specific MAC connotation
•
•
Refer to Aboba draft
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 ?
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
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!
How to Fix 802.21-2008
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Dual Radio Handovers
3GPP Network
• Both Radios are connected to
network at the same time
1
eNB
3GPP EPC
Interne
t
• The platform needs to support
simultaneous Tx/Rx
• MS uses target radio to prepare
resources in target network
2
MS
BS
3
ASN GW
4
WiMAX Network
eNB: eNodeB
BS: Base Station
EPC: Evolved Packet Core
ASN: Access Service Network
GW: Gateway
MS: Mobile Station
•
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
Single Radio Handovers
3GPP Network
• Only one radio is connected to
network at any time
1
eNB
2
3GPP EPC
• Only one radio is Tx at a time
• MS uses source radio to
prepare resources in target
network
Inter-System Tunnel
b/w Networks
MS
Interne
t
SRS
SRS: Single Radio Server
4
BS
ASN GW
3
5
WiMAX 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
WiMAX Single Radio Handover Messages
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
Mobile
Station
5. Registration (REG_REQ/RSP) Messages
WiMAX
Network
6. Transport Connection Establishment DSA_REQ/RSP/ACK
7. IP Address Allocation (DHCP)
Messages over air-interface for initial network entry for WiMAX
MS
IP Tunnel
Source
Network
IP Tunnel
Single Radio
Server
IP Tunnel
Target
Network
N/W Entry Messages over L3 Tunnel for Single Radio HO from 3GPP to WiMAX
Dual Radio Handover Procedure
Source
Access
UE/ MS
Target
Access
N/W Mobility
Manager
Information
Repository
AAA
HA
1. Data Traffic through Source Access Network
2. Target RAT System
Information Broadcast
3. Policy and Target RAT Information Query/Response
Network
Discovery
&
Selection
4. Turn on Target-RAT(s) radio.
Inter-RAT scanning
5. Target RAT-Measurement Reporting (Optional)
6. Target RAT Selection
and HO Decision
7. Inter-system Handover Procedure (Dual/Single radio Handover)
8. Target RAT Network Entry Procedure
9. Switch Radio Trigger
11. UE/MS IP Address Resolution
12. Data Traffic through Target Access Network
10. Mobility Protocol Binding Update
Dual Radio
Handover
Procedure
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
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802.21 Evolution
Multi-Radio Activities in IEEE 802.21
•
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 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
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