1. IEEE 802.21 MEDIA INDEPENDENT HANDOVER
DCN:
Title: Report on Potential Link Syn Events for IEEE r
Date Submitted: Jan 9, 2006
Presented at IEEE session #12, Big Island, Hawaii
Sources : Ajoy Singh, Qiaobing Xie, Yogesh Bhatt
Abstract: This is our report on an action item taken from the last session with the aim to investigating and identifying any r link events that can potential be considered as new link sync events.

2. IEEE 802.21 Presentation Release Statements
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3. Background
An action item was given at the last session to investigate whether there are any existing r native link events that are potentially of value to the upper layer MM decision making if passed as additional MIH link sync events.
This is our report on our preliminary findings.

4. IEEE 802.11r Mobility Management Overview
IEEE r supports following 3 types of mobility management:
No-transition: In this type, two subclasses that are usually indistinguishable are identified:
Static : no motion.
Local movement: movement within the PHY range of the communicating STAs
BSS-transition:
Station movement from one BSS in one ESS to another BSS within the same ESS.
ESS-transition:
Station movement from a BSS in one ESS to a BSS in a different ESS.
This case is supported only in the sense that the STA may move. Maintenance of upper layer connections cannot be guaranteed by IEEE ; in fact, disruption of service is likely to occur.

5. 802.11r Background (Reused form .11 liason doc)
Fast Transition: optional capability of APs and STAs
TAP = Fast Transition Enabled AP
TSTA = Fast Transition Enabled STA
Five stages of BSS – BSS transition:
Scanning – active or passive for other APs in the area
Authentication with a (one or more) target TAP
Re-association to establish connection at target TAP
Have a connection, but still can't *DO* anything…
PTK derivation – 4-way handshake of session keys
QoS admission control to re-establish QoS streams
Next question: exactly how are keys moved around?
May need new IP-based protocol(s)

6. Potential MIH link synchronous events for .11r
No Transition: Not applicable.
BSS Transition: MIH Link synchronous events could be defined and used for upper layer smoothing (e.g., enabling and disabling transport layer congestion control).
ESS Transition: Link synchronous events could be defined and used to perform make-before-break L3 handoff.

7. Potential Link Synchronous Triggers from 802.11r MAC
Mobile AP
MAC
SCANNING (1)
Potential Link
Sync Trigger
AUTHENTICATION (2)
Potential Link
Sync Trigger
RE-ASSOCIATION (3)
PTK-DERIVATION (4)
Potential Link
Sync Trigger
QOS ADMISSION CONTROL (5)
Potential MIH Link Sync Events Trigger Points