tdoa3 random send, packet will conflict, PTP(Precision Time Protocol) can solve it

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justinleeyang
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tdoa3 random send, packet will conflict, PTP(Precision Time Protocol) can solve it

Post by justinleeyang » Fri Jun 14, 2019 4:04 am

hi,

tdoa3 random send, packet will conflict,I think that PTP(Precision Time Protocol) can solve it.
PTP can sync all anchor time, then every anchor run tdma mechanism to avoid collision。



arnaud
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Re: tdoa3 random send, packet will conflict, PTP(Precision Time Protocol) can solve it

Post by arnaud » Mon Jun 17, 2019 6:49 am

TDoA2 is synchronizing all anchors and using TDMA. The problem with the TDMA approach is that it does not scale that well.

First of all, in TDoA2 we use anchor 0 as a master clock for TDMA, this means that losing anchor 0 stops the system. Having a more distributed approach for time-keeping would solve this problem. If you have an idea about such an algorithm that would be great. Raw PTP assumes one source for the clock as far as I understand so it would not solve this problem.

The main problem is a scalability one: we need to assign one TDMA slot per anchor. This is great in a small system when all anchors sees each-others. When the system becomes bigger we either slow down the system very much by not re-using time-slot and having a lot of timestots or we risk collision by re-using time-slots for anchors that might have an overlapping coverage. Overall it seems that handling such a system will become very complex and hard to setup.

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