Two tags with same 16-bit address in the same area

Wireless Connectivity Ultra-Wideband
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1

Hi,

While I was configuring the DWM1001C which is placed on my customized PCB, I found that two of the tags have same 16-bit address. Will there be any issue if these tags are next to each other in the same area?

Thank you

2

Hi @kanpinyo
Im considering that you are using PANS software. There is a (probably) low chance that you will have some duplicates in your network which you already have. Unfortunately it could create some random issues in the network especially when they are close to each other. If they will never be in range with each others and the cluster distance will be at least 2 (so 1 AN will never have in range those two tags) you can run them in one network.

I would not recommend you to run a network with a duplicate 16bit address.

Cheers
JK

3

Thanks you @leapslabs

Yes, I use PANS software. By the way, I still wonder if there is any combination that two modules with same address can be used, for examples,

  • Two anchors with same address in the same PAN ID but they are not seeing each other
  • A tag and an anchor with same address in the same PAN ID

Edit: There are 100s anchors and 10s tags in the network, so it might have a chance that this issue will occur in other combinations as in the example.

4

Hi @kanpinyo
first of all Im pretty much convinced that the PANS gateway (+ web + Android app) can not handle this correctly. I do not have with me two devices with the same HWID so I can’t test it. But I believe that it will end up in some mixed configuration in MQTT.

Beside of that running two AN with same HWID is possible but they must be isolated within the network in the meaning that there must not be an anchor that will hear both devices at the same time. So the separation must be like AN(0x1111) <-> AN (0x1234) <-> AN (0x4321)<->AN(0x1111)

You must need to keep in mind that some time the signal from node propagate to much more far distances that you would expect (even +70m is possible under very specific condition).

Running two tags) as above, they cannot be seen by one anchor at the same time.

Running 1x tag + 1x anchor) I dont see any potential issues here except the stuff related to the bridge as described above. Im trying to check this with my colleagues.

Cheers
JK

5

Thank you very much for the detailed clarification @leapslabs

Regarding your concern, I am not running any bridge node or Raspberry Pi gateway in the network. The only thing I use that you mentioned is an Android app which I use to initially configure some settings and occasionally change anchors position.

In the case of two tags with same address, when I power on only one tag at a time, the Android app registers two tags as separate nodes. I will do further test which is powering on two tags at the same time and report you back.

To be more clear, they have same 16-bit address but 64-bit address are different. But from what I know is that PANS only uses 16-bit address to communicate in the network, isn’t it?

6

Hi @kanpinyo
the android app might be using BT mac address to distinguish between nodes.

Yes the PANS is using only 16bit from the 64bits.

Cheers
JK