Sending user data without anchors

Dear all,

I am trying to sending user data with out anchors, just with one tag and one gateway only.

I tested using “dwm_usr_data_write” function on API and it only sends data msg when location value was exist and uploaded which means I need anchors just want to send IoT data of Tag.

Can I send usr_data with out anchors? If possible, please reply me some sample code…


Do you need to use the PANS library and not use TWR at the same time ? Then why PANS lib. Many libraries support even 802.15.4 over uwb which is a mesh networking so you can send anything anywhere. Or I misunderstood your use case.

Thanks for reply. Currently, I want to make system with PANS library. Some tag sends localization info and other sends data info to gateway. And I though that editing some codes in PANS library code with “dwm_usr_data_write” function will solve the problem easily.

There is a description in the document “DWM1001 System Overview” especially in section 4 “DRTLS Network, Configuration and Control”. As you can see, there are only three Types of devices anchors, tags and gateway, there is no differentiation between tags that send position and tags that do not send position. As you can see there is a single “Superframe structure” and particularly this sentence “At the end of the ranging exchange the tags can either receive 34B data from the network or send 34B to the network through the gateways”
That means that when no ranging is ongoing there would probably be no IoT data frames exchanged.
This is my interpretation, please have a closer look and read of the documentation and keep in mind that the PANS lib is not very flexible in terms of functionality and target one use case.
An additional note, when it comes to user data it is also possible to use an nRF52 back channel like they do for configuration with BLE, see BLE API on section 7.


it is not possible to send, receive data to/from the gateway without anchors. You need at least one anchor as initiator to initiate the UWB network.


Thank you @wassfila and @leapslabs.
The result is a little regrettable, but it was very helpful.
I will find another way to send data without anchor.

Hi @leapslabs
Regarding to your coment above, I wanna make sure that we can send/receive data to/from gateways as long as there is only an anchor for configuring the UWB network.
That is, is the data exchange of each tage possible under the condition of [multiple tags, one anchor, and multiple gateways] assuming that we can squeeze dummy ranging data for each tag ?

Hi @minsu,

yes, you can send/receive data to/from multiple tags if you have at least one anchor(must be initiator) and you need at least one gateway. I’m not sure what you mean by " we can squeeze dummy ranging data for each tag".