On 27/03/14 19:13, Phoebe Buckheister wrote: >> Is it possible for a device to co-ordinate more than 1 WPAN on the same >> PHY, beacon enabled or beaconless? >> If so is it possible to bridge or route from one WPAN to another within >> a device over the same PHY? >> Can a slave join more than one WPAN, again using the same PHY? > Theoretically yes on almost all accounts, practically on none right now > and probably ever. To be part of multiple WPANs, a device *must* send ACKs > in time for those frames that request them, coordinators and > non-coordinators alike. That is hard (if not impossible) to get working > correctly within the specified time frames without any hardware support or > an RT kernel (and even then it's tough for the faster PHYs). Better don't > count on it. > > That "multiple associations per PHY"-thing was actually discussed to some > length a week or two back on this list and netdev. My takeaway from that > is "not now, not ever", and I intend to completely remove the ability to > register multiple WPANs per PHY in the near future because all currently > possible uses of multiple WPANs as possible now can be implemented without > breaking netdev semantics and with actual guarantees in a slightly > different manner. > > Bridging is entirely impossible due to the ACK frames, unless you find it > acceptable to incorrectly have a device assume that a frame was received > by the intended recipient when that hasn't yet happened. Routing is not > defined for 802.15.4, but upper layers (say 6lowpan/IP) can do that just > fine. > Hi Phoebe,
Thank you for the swift response it has given my a lot to think about. I remember the discussion and like you I was in favour of removing the slave list. But as chance would have it I think we may actually need it now or some other method of multiple WPANs per PHY. I need to have a think especially with regards to ACKs as this is something I haven't thought about. I don't suppose you can you expand on why bridging is impossible due to the ACK frames? ------------------------------------------------------------------------------ _______________________________________________ Linux-zigbee-devel mailing list Linux-zigbee-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-zigbee-devel
