This is a nice start for what i'd call poblem 2): making multipoint delivery of serious amount of data to more receivers more reliable. Would love to understand if there is any definition of how this would or could be used for actual IP multicast, eg: where is the definition of using IGMP membership reports to track receivers, automatically define a GCR etc. pp ?? I'd be surprised if 802.11 would elevate to that level... Maybe thats something we could/should do ?
But yes, this is not solution to problem 1) which is about IP signaling protocols that currently rely on multicast. We should target something that has a lower set of requirements against APs (like worst possible AP needs to work for us), and we probably want to take more care of battery. (I say probably because i still haven't seen good simple but persuasive numbers for wifi-multicast vs. real world batery drain, so i am operation on a faith base only here which i don't particularily like. ) On Mon, Aug 10, 2015 at 10:42:40AM +0200, Henning Rogge wrote: > On Mon, Aug 10, 2015 at 10:34 AM, Mikael Abrahamsson <[email protected]> wrote: > > Donald Eastlake posted this a few days ago: > > > > "- 802.11 does have a feature called GCR -- Groupcast With Retries, > > which was part of the 802.11aa amendment, although it is not widely > > implemented. It includes such features as a way for the AP to send > > several multi-destination frames and then, using unicast, to poll > > associated stations for a bit map of which of those frames they > > correctly received (BlockAck) and a feature for the AP to > > spontaneously transmit a multi-destination frame more than once > > without causing confusion for improved reliability." > > Okay... > > this is quite new and I am not sure it will solve all the multicast > problems for 802.11. Neighbor discovery (both IPv6 and routing > protocol) has potentially to deal with a lot of neighbors, some of > them not even known to the transmitter. It also feels like a lot of > consumed airtime to replace a multicast with a multicast and one > unicast for each known neighbor. This could be dozens of media > accesses. > > Henning Rogge _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
