On Fri, Oct 31, 2003 at 02:38:28PM -0800, Geek wrote: > Thanks bob. But i have an extension to my second > question. What if two ad hoc groups (A,B,C) and > (D,E,F) using the same frequency channel and same > SSID, come close to each other? Will they end up > forming a single group? or will the BSSID's of the > nodes be used to differentiate which nodes are in your > group? > Is there any work anyone knows that has characterized > the overlapping of ad-hoc groups?
An 802.11 radio that meets the WECA interoperability standard will join the "oldest" network it hears on the same channel with the same SSID by adopting that network's BSSID. Stations in "older" networks send beacons with a higher Time Synchronization Function (TSF) timestamp than stations in "younger" networks. I think that WECA calls this function, "IBSS coalescence." Typically I call it an "IBSS merge." It appears that Prism station firmware versions >= 1.3.9 will do this. So will late versions of Lucent/Orinoco/Agere/Avaya firmware (I don't know the earliest version number, sorry). At one time, Cisco Aironet firmware would not do IBSS merges; hopefully, late versions are fixed. New 802.11 MACs by ADMtek, Realtek, and Atheros delegate a lot of functions to the host which firmware did in the previous generation of 802.11 MACs. It seems IBSS merges have become a host function. It will depend on the quality of your drivers whether or not you will get a proper IBSS merge with the new chips. Dave -- David Young OJC Technologies [EMAIL PROTECTED] Urbana, IL * (217) 278-3933 -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
