Transcript ES_dot21_april2007

IEEE 802.21
SDO Emergency Services Coordination
Workshop
Washington DC, April 2007
Gabor Bajko
Content
Motivation for IEEE 802.21
Scope
Overview of IEEE 802.21
802.21 relation to Emergency Services
Motivation
• Increasing number and types of interfaces supported by devices (multi-radio)
• New problem space: inter-technology handover
• Currently network selection is done based on a single criteria, like signal strength
or static list of preferred networks
• Characteristics of the target network are not known in advance
• The abundance of available networks with different characteristics is currently not
exploited by devices running applications with very different needs
• Do something to help devices in network selection and handover decisions
Scope
Handover
Initiation
Handover
Preparation
Handover
Execution
Scope of 802.21
Search New Link
Setup New Link
Transfer Connection
Network Discovery
Network Selection
Handover Negotiation
Layer 2 Connectivity
IP Connectivity
Handover Signaling
Context Transfer
Packet Reception
IEEE 802.21 helps with Handover Initiation,
Network Selection and Interface Activation
Media Independent Handover (MIH) Services
• Classification
• Information Services (MIS)
MIH Users
MIP
TCP/IP
VPN
Others
• Event Services (MES)
• Command Services (MCS)
MIH
Command
Services
MIH
Information
Services
MIH
Event
Services
• The MIS and MES/MCS services
could be implemented
independently
MIH
Link
Command
Services
Link
Information
Services
Link
Event
Services
Link Layers
802.11
802.16
3GPP
3GPP2
MIH Information Services: Data structure
MIS access from Serving Link
MIS
Server
A2
Serving
Access
Network
Access
Network #2
Access
Network #1
B
PoA1
PoA2
2. L3 MIS Query
5. Handover
e.g. Mobile IP
1. Broadcast
1. Broadcast
3. Network Selection (#1)
4. Initiate Mobility Signaling
A1
MIS access using Detected Links
Internet
MIS
Server
MIS
Server
3b. L3 MIS Query
2b. L3 MIS Query
Serving
Access
Network
Access
Network #2
Access
Network #1
PoA1
PoA2
2. L2 MIS Query
6. handover
3. L2 MIS Query
1. Broadcast
1. Broadcast
4. Network Selection (#1)
5. Initiate Mobility Signaling
MIH Event Services
• MES provides current link or new link
status information to MIH users
• Examples: new-link-detect, link-up, linkgoing-down
• Useful for
• initiating MIS queries
MIH users
MIH
Events
MIH Function
• Reporting link behavior affecting mobility
• Network can take mobility action
• Also useful for network nodes to send
dynamic status information to the users
impacting their current link conditions
Remote MIH
Events
Link
Events
Event sources (link)
MIH Command Services
• MCS provides mechanism for one point to
request execution of certain commands in
the remote end point
Command sources
• Examples: link-scan, link-switch
• Execution of commands may impact the
current link connectivity
• Useful for network selection and handover
control
MIH
Commands
MIH Function
Remote
Commands
Link
Commands
Link Layers
Types of Handover Based on Control Model
• Terminal Controlled
• Terminal may make use of some MIH services
• Terminal Initiated, Network Assisted
• Terminal makes use of MIH Information Service
• Network Initiated and Network Controlled
• Network makes use of MIH Event and Command Service, plus Information Service
knowledge, to decide if handover is needed/desired, to decide the target, and to
command the terminal to handover
802.21 role in Emergency Services context
New MIH Information Element: LCP
The supported Location Configuration
Protocol in the target network is not known.
TYPE_IE_NETWORK_LCP= …
The new Information Element lists the
supported Location Configuration Protocols
in a given network.
The new IE is intended to help in the
network selection process.
Unauthenticated network access
• For the cases when AP is not open access, a dummy and/or null authentication
for emergency services access to be specified
• Emergency identifier and auth type to be provisioned in the Information Server
STA
802.21
IS
AP
Get Information Req
(Request for Emergency IE)
State-1 Query Mechanisms
Get Information Resp
(Emergency IE )
Determine the
AUTH support
Authenticate
Determine Location Information
Place an Emergency Call
AS
Summary
• With technology advances in Devices, Networks and Usage Models, Multi-radio
operation is becoming the norm
• 802.21 enables Co-operative Handover decision making between Clients and
Network by helping with Handover Initiation, Network Selection and Interface
Activation during handovers
• 802.21 Information Server can help bootstrapping information required for
unauthenticated access and network supported LCPs