Download 00-03-0022-00-0000Handoff_WNG_Presentation_r3

July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
802 Handoff Presentation to WNG
David Johnston
[email protected]
[email protected]
Submission
Slide 1
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
First Session of 802 Handoff
ECSG Launched, May 2003
• Attendance
– Monday – 30
– Tuesday – 19
– Thursday – 22
• Total Attendance – 45
• 29 Separate organizations represented
Submission
Slide 2
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Officers
• Chair
– David Johnston, Intel
• Reluctant Recording Secretary
– Michael G Williams, Nokia
• Vice Chair
– Ajay Rajkumar, Lucent
Submission
Slide 3
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Charter
• Consider the possibility of specifying a
common handoff framework application to
802 standards, wired and wireless
• Consider placement of work (In a new
working group or 802.1)
• Authorized to draft a PAR
Submission
Slide 4
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Objectives
• Define scope and requirements
– May work with all MACs and PHYs
• Without unnecessary overhead
• 802.x  802.y (where x could equal y)
• 802.x  non 802
– Consider how to address Authentication and Security
• Within the PAR? Coordinated with Link Security group
• Specify a framework that 802 MACs can adopt
– MAC SAP Messages
– MIB Entries
– Other?
Submission
Slide 5
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
What it is not
• It is not proposed to implement a protocol for
handoff
– We are at the link layer. What are we handing off?
– Entire problem cannot be solved at layer 2
• So this is not a handoff standard!
• Assumption that upper layer ‘thing’ can handoff
(mobileIP, voice bearer etc)
• Addresses L2-L3 coupling of handoff process
Submission
Slide 6
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Example Scenario
• Multi interfaced device
– Docked Laptop with 802.3, 802.11 and 802.16e
– Mobile IP session being used for VoIP and web traffic
• Laptop undocks
– Needs to make a timely decision to switch to 802.11
and attach to a suitable AP.
– Existing traffic should suffer minimum interruption
• Laptop moves out of building
– Needs to make a timely decision to switch to 802.16e
and choice a suitable BS
– Existing traffic should suffer minimum interruption
Submission
Slide 7
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
• Focus is on
What it is
– Enabling good handoff decisions
• Handoff decision data with interface
• Useful beacons/SSIDs/etc.
• Unambiguous DNA hints
– Signaling appropriately to L3 handoff capable entities
• L2 triggers
• Wired and Wireless
– 802.[11/15/16] to 802.[11/15/16] are important cases
– 802.3 to 802.[11/15/16] are important cases
– 802.x to cellular is an interesting scope problem
Submission
Slide 8
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Handoff Mechanics & Domains
• Within a network type and administrative
domain
– The network standard owns handoff
• 802.11 ESS handoff, 802.16e handoff
• TGi ‘fast roaming’
• Handoff-Req Handoff-Resp, Context blob motion,
IAPP etc etc
Submission
Slide 9
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Handoff Mechanics & Domains
• Between administrative domains and between
heterogeneous network types
– No handoff mechanism is defined or is definable in the
general case
• What is being handed off? An 802.11 association does not map
onto an 802.16 registration
• But it can be done at a higher layer
– E.G. Mobile IP
• 802 Level provisions are needed to optimized this
case
– This is where 802 handoff fits in
Submission
Slide 10
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Triggers
• Bad name
– Don’t always lead to an action
• Hints is a better term preferred by smarter people
than me
• Link up is badly defined
– Different between 802.11, 802.11i, 802.11f
– Before/after association or authentication?
– We can define trigger independent of media
• When can the upper layer data flow unimpeded
Submission
Slide 11
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Handoff Decisions
• On what do you base a handoff decision outside of
a managed network/ESS domain/interface
boundary?
• Some common information would be nice and a
common way of getting at it
• Lots of good decisions to make
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Submission
Can I authenticate here?
Is this in a subnet I have a DHCP lease in?
Is there IP above the LLC?
How much will this cost me?
Can I expect my upper layer thing to hand off here?
What APs are nearby, what channel are they on?
Slide 12
David Johnston, Intel
July. 2003
doc.: 00-03-0022-00-0000 Handoff_WNG_Presentation r3
Handoff Decision Data
• There is a need for and information base
containing this data
• It needs to be interfaced to
– Encapsulation for transport
• ASN.1/DER, XML, Canonical S expressions
– A path from mobile to fixed part
• Uncontrolled port access?
– An interface/API
– Motion of data between neighbors
Submission
Slide 13
David Johnston, Intel