MDEK1001 Ranging


at the moment the TAG provide me a position and ranging information for 4 Anchors. The TAG decide on his own, which anchor is the best for his solution.

I want to get the all data from every anchor -> max = 16.

How to get the ranging information for every anchor ?

Second Question:
can you provide the BLE nrf software? i find out that the BLE-Tag save the 4-anchor information in the following charakterisik: 003BBDF2-C634-4B3D-AB56-7EC889B89A37
But i want to save there all 16 anchor informations.

best Regards,

Hi Roman,

The system is designed in a way the tag will range to only 4 anchors, so i think what you try to achieve is not possible with the PANS software (software provided with DWM1001 family products.)

Maybe take a look at the DWM1001 system overview, it should give you a good idea of what can be done.


hi [color=#333333]Yves,[/color]

[color=#333333]thanks for your reply. If i understand right, the whole system if made to synchronise and handle up to 16 anchors right?[/color]

[color=#333333]If i look in the code : DWM_LOC_CNT_MAX = 15 if i connect more then 4 anchors in the field and flash the tag, then i should see more then 4 anchors. Because, the tag is first ranging for all of them and then decide which is the best for localization. [/color]

[color=#333333]Here maybe i understand something wrong: “A tag collects information about anchors by listening to the Beacon messages. It will create a list of anchors from which it already received the positions. Then it will calculate distances to each of the anchors on the list, based on its current position (if it does not know its position it will use 0,0,0) it can then decide which anchors to choose for the next measurement using the following criteria:”[/color]

[color=#333333]so how to get the data of all anchors?[/color]

[color=#333333]best Regards [/color]

Hi Roman,

The system is built around repeating superframes. Each superframe contains 16 beacons messages which correspond to 16 anchors.

A tag will ever perform Two Way Ranging with 4 anchors only, and calculate position relatively to those 4 anchors.

The section you are referring to explains how the tag will chose the 4 best anchors to perform TWR with. In this initial phase, the tag will use its last known position to calculate it’s distance to the 16 anchors that provide their coordinates. But this is not real time. The only objective there is to determine the best 4 anchors for two way ranging.

So with this system, a tag will perform TWR with maximum 4 anchors and calculate position estimate with location engine. Note that ranging to 3 anchors is sufficient for the location engine.

Hope it’s clear.

Hi Yves,

its not clear for me because if i read the documentation i understand the following:
(System Overview Site 19-20)
One Superframe(100ms) contains 15 TWR(Two Way Ranging) Slots.
One TWR(Two Way Ranging) slot is 5 ms long. Where 4 Devices AN_A, AN_B, AN_C, AN_D are polling and get the answers and calculate the location.

If i understand right, then currently only one! TWR Slot is using? or All 15 TWR slots are used for the same 4 Anchors?
Is it possible to change it? I want the timestamps(measurements,distance) for all 15 anchors.

Best Regards,

Hi Roman,

Each TWR slot will be used by a single tag, and a tag cannot use more than one slot in the superframe.

So if we have 15 TWR slot, it means maximum 15 tags can range with the 16 anchors (16 beacons in the area.) Each tag will perform TWR with only 4 anchor, automatically chosen based on their position.

A single tag will not use more than 1 TWR slot in a superframe, and it will range to only 4 anchors.

With the DWM1001 system and software, it is not possible to get time stamps for 15 anchors with a single tag.

Hope it helps,