1. CPVs in Mesh formation Date: 2008-09-08 Authors: September, 2008
Feb, 2008
doc.: IEEE /xxxx
September, 2008
CPVs in Mesh formation
Date:
Authors:
Dee Denteneer, Philips
Liwen Chu, STMicroelectronics

2. Resolve a number of CIDs on the use of the CPV during mesh formation
September, 2008
Resolve a number of CIDs on the use of the CPV during mesh formation
CIDs: 428, 429, 924, 496, 1044, 1045, 287, 650
Dee Denteneer, Philips

3. Channel precedence value
September, 2008
Channel precedence value
Recap:
4 octet field in mesh configuration element
Contains a random value of 31 bits
Used in mesh formation and channel switch
We consider mesh formation only:
In case MESH STA detects candidate peers on different channels, it selects the peer with the numerically highest channel precedence value
Several issues in comments
Dee Denteneer, Philips

4. Channel precedence value: issues
September, 2008
Channel precedence value: issues
Is not what one wants: (429, 924, 650)
429: MESH STA in mesh should get high priority in channel selection
650: “Although the sentence here requires MPs to operate the unification of the channel unconditionally, some MPs within a mesh would like to oprate on a different channel, depending on the bridging function within an MP which has multiple radio capability. This channel unification should not be mandated.”
Dee Denteneer, Philips

5. Channel precedence value: timing issues
September, 2008
Channel precedence value: timing issues
Leads to detailed timing issues:
428:
if new MESH STA, joining a mesh, has higher CPV?
“Because the mesh configuration IE is carried in beacon/probe responses, an MP needs to configure it before it does anything else.”
Dee Denteneer, Philips

6. CPV: Multi-radio issues
September, 2008
CPV: Multi-radio issues
CID 28, 426, 496, 1167, 650
There seems to be a hole in the use of CPV for multi-radio, as all neighboring MPs are forced to select the MP with the highest CPV. Hence, one radio is ignored.
Conversely: if the device has two radios, both are mandated to use the same channel
Dee Denteneer, Philips

7. Having a CPV leads to issues in switching (1044, 1045)
September, 2008
Having a CPV leads to issues in switching (1044, 1045)
1044: how is the new CPV chosen
1045: Having one leads to algorithmic problem during switching (i.e there is a cpv associated with the current channel)
Defines an increasing sequence that ultimately converges and invalidates further use
Dee Denteneer, Philips

8. Suggestion Remove CPV-usage for mesh formation
September, 2008
Suggestion
Remove CPV-usage for mesh formation
Introduce a bit (e.g. in mesh flags field) indicating being part of a mesh or connection to portal
Additionally include some channel characterisation (e.g. number of peers, CSA-measurement)
Use the channel switch protocol to coalesce the mesh to one channel.
Dee Denteneer, Philips

9. Straw poll Should we A: Retain CPV for mesh formation
September, 2008
Straw poll
Should we
A: Retain CPV for mesh formation
B: Introduce a bit to indicate whether the MESH STA is connected to a portal
C: Introduce a bit to indicate whether the MESH STA is part of a mesh and include some channel characterisation (e.g. number of peers, CSA-measurement) as well
D: don’t know/care
Dee Denteneer, Philips