CPVs in Mesh formation Date: 2008-09-08 Authors: September, 2008 Feb, 2008 doc.: IEEE 802.11-07/xxxx September, 2008 CPVs in Mesh formation Date: 2008-09-08 Authors: Dee Denteneer, Philips Liwen Chu, STMicroelectronics

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

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

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

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

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

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

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

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