Hi,
Let’s say we have two dw1000 senders and one receiver (all 3 are configured identically).
Is it theoretically possible that SFD (and timestamp) is received from sender1 but data from sender2 if sender1 and sender2 start transmission at about the same time?
Can this message then be received as a valid message (pass crc check, etc.)?
Hi,
It is in theory possible that SFD (and timestamp) is received from sender1 but data from sender2 if sender1 and sender2 start transmission at about the same time.
However to ovoid collision from happening one could use a time slotted scheme for TWR (as we do in TREK) and/or use any of the MAC functions we have like Frame filtering or crc checking. See section 5 on page 49 in the IC user manual version 2.13 (which is the latest version)
Also of interest may be dynamic preamble select (DPS) intended for use as security mechanism for two-way ranging. (section 10.5 in the UM)
/Leo
We have seen this happen a few times in a time slotted system where the same time slots are re-used by beacons separated by a distance which should normally be long enough to prevent this from happening. In some cases the terrain has been such that both of the overlapping beacons have been received and no errors are produced, but the distance is simply ridiculous due to the timestamp coming from the far-away beacon, but the rest of the data from the nearby beacon.
Hi Leo,
If we use frame filtering, the CIR will also not have the FP of rejected frame?
Regards,
Shijo Thomas