Setting up massive # of 802.15.4 networks in same area

XBee & XBee Gateway XBee - 802.15.4
1

We are trying to setup several (12+) non-beacon w/ coordinator networks in the same building and running into some difficulties. We are using XBee Pro 802.15.4 modules on full power and running into issue when starting up and getting the coordinator setup.

Haven’t changed the CA (Channel Clear Assement) value yet but we have changed the RN (Random Delay Slots) to a value of 1 in all of the radios. Does changing that to 1 universally basically null out the advantage of RN since they are all set to 1?? I can change some to 2 and others to 3 but didn’t know if that would help or not.

We are currently trying out a new longer scan duration but not having much luck.

Any suggestions for running/starting this many networks in the same area would be greatly appreciated.

Thanks,
Matt

2

Well… The scan duration didn’t fix it… Just made the failure mode taking longer to happen…

Working on random delay now…

3

No joy there either… Increasing the random delay doesn’t improve our chances of getting all of the 802.15.4 networks to start up.

What is a reasonable number of 802.15.4 networks to expect to be able to run in one location? I know it depends on the duty cycle of the radio but according to our wi-spy spectrum analyzer we are only running 2-5% duty cycle depending on if there are one or two networks on a channel at a time.

4

We changed a few more settings in our equipment and cleared up most of our problems. We had a watchdog that was resetting parts of the system and throwing off some of the timings.