Transcript Scope and Proposed Items

IEEE 802.21
May 2004
Steps in Handoffs
and Use Cases
Vivek Gupta
Intel Corporation
[email protected]
May 2004
Submission
Slide 1
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Background….
• IEEE 802.21…from PAR and 5 Criteria
– Media Access Independent mechanisms to facilitate
optimization of L3 handoffs (e.g. Mobile IP sessions)
between homogeneous or heterogeneous media types
– Optimize Detection and Selection of Network attachment
points
– Ensure compatibility with the 802 architectural model
and security mechanisms
• No new security algorithms or protocols
Submission
Slide 2
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Background…Scope of 802.21
zG (WWAN)
802.Y
802.X
802.X
• Intra 802 Handoffs (802.x  802.x)
– Covered by respective 802 working groups
– These 802 WGs will also deliver fast intra 802 handoff solutions that
address ~30 msec or less handoff latency
• Through proactive pre-authentication, soft handoffs, and/or fast
reconnections between nodes (TGr, TGi, etc. for 802.11)
• Inter 802 Handoffs (802.x 802.y) and extension to more
general case of inter network handoff across cellular systems
(802 zG)
– Within scope of 802.21
– Intra 802 Handoffs across Administrative domains also within scope
– Handoffs across 802.11a, 802.11b, 802.11g, 802.11n in scope?
Submission
Slide 3
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Customers of 802.21
• Layer 3 and above applications…
– Mobile IP for data transfers
– Voice based applications
• Network Selection Service
– Select best radio
• Others?
Submission
Slide 4
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Steps in Handoff Process
•
Scenario
–
•
Multi radio mobile handset roaming in heterogeneous
wireless network environment….
Steps in Handover




Submission
Detect Changes in Link Availability
L2 Connection and Network Provider Selection
Link Selection and Configuration
Connection Handover
Slide 5
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Steps in Handoff Process
 Detect Changes in Link Availability
–
Availability of New Links
•
Through Native radios
–
•
Media Sense and Link Quality Estimation
Through non-Native radios
–
–
•
–
E.g.Using 802.11 radio, find out about all other radios in vicinity
Site Report for all radios (Global Network Neighborhood)
GPS assisted
Degradation and Loss of Existing links
•
Link Quality estimation and comparison
–
Signal Strength, Signal to Noise Ratio, Bit Error Rate
=> Link layer Triggers to notify higher layers
Submission
Slide 6
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Steps in Handoff Process

L2 Connection and Network Provider Selection
–
Establish L2 connection with Available Links
•
Need Radio specific MAC level parameters
–
–
SSID, BSSID, Channel, etc.
Network Provider Selection
•
•
Based on preferred operator and available services
Provisioning utilities like Microsoft WPS may do most of the work
here
–
There may be other cases where WPS may not be applicable, (Low
power mode of operation)
=>Extended Site Report (Global Network Neighborhood) can help
with Link discovery and selection
–
Link layer parameters for existing radios (no probes, beacons,
scans, etc.)
–
Service provider information
Submission
Slide 7
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Steps in Handoff Process
 Link Selection and Configuration
–
Link selection
•
•
–
Link Configuration
•
Submission
Input from user policies, available links and
services, etc.
Mostly an OS function
IP connectivity
Slide 8
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Steps in Handoff Process
 Connection Handover
–
Decision to switch Connections or Maintain
simultaneous connections etc.
•
•
–
–
Submission
Make before Break
Break before Make
Context Transfer
Application specific
Slide 9
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Use Case #1
Steps in Handover
Wired  Wireless
(Email)
Comments
Changes in Link
Availability
Abrupt!
Link_down
L2 Connection and
Network Provider
Selection
WLAN, BT, WWAN
(Global Site Report)
802.21 can help with
Network Discovery and
Selection
Link Selection and
Configuration
Select WLAN and get
IP connectivity
Based on policy, cost,
bandwidth, etc.
Connection Handover Break before Make.
Email app reconnects
No need for MobileIP!
For other Wired  Wireless transitions, for time/latency critical applications user
may want to use wireless even when device is NOT mobile. E.g. VoIP Phone
Submission
Slide 10
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Use Case #2
Mobile user using VoIP over WLAN in office walks out, gets into car,
and drives out of town!
Steps in Handover
Changes in Link
Availability
802.11  802.16  Cellular
(Voice/Video)
Gradual decay…….
Link_Going_Down
Link_Up
Comments
802.21 can specify
Predictive Triggers.
L2 Connection and Get network and provider
Network Provider preferences. Get provider
specific access info.
Selection
802.21 can help with
Provider Selection and
Access info
Link Selection and Select network and get
Configuration
connectivity
Notify TCP appropriately when
going across networks with big
difference in bandwidth
Connection
Handover
Seamless handover
Submission
Make before Break.
Slide 11
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Use Case #3
User roaming in an airport across domains and Service Providers.
802.21 facilitates handover to preferred Network Service Provider
Steps in Handover
Changes in Link
Availability
Connected to 802.11
(User roaming in an airport)
Link_Available!
Comments
Better service provider
available, based on Global
Site Report…
L2 Connection and Select the new/preferred
Network Provider service provider
Selection
Link Selection and
Configuration
Connection
Handover
Submission
Break before Make…
Slide 12
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
802.21 Work Items
• Things to do in 802.21
– Use cases
• Find compelling user scenarios to solve
– Global Network Neighborhood
• Discover about other radios through current radio
• Neighbor graphs of all radios
– Media Independent Triggers
• Notifications about changes in link availability
• Things NOT to do in 802.21
– Link Quality Comparison
– Link Selection
• Policy decision (Mostly an OS function….)
– Connection handovers
• Make before break etc. (Application specific…)
Submission
Slide 13
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
IEEE 802.21 Specification…
• General organization of 802.21 specification
– Type of Spec
• More general and abstract in nature than other 802 specs
– Customers of spec
• Other 802 WGs and other Standard bodies
– Normative vs Informative
• How will compatibility with 802.21 enforced/measured
– Mapping to other technology
Submission
Slide 14
Vivek Gupta, Intel Corp
IEEE 802.21
May 2004
Conclusion
• Key areas of contribution for 802.21
– Media Independent Triggers
– Global Network Neighborhood
Submission
Slide 15
Vivek Gupta, Intel Corp