Distance between anchors and Listener, TX Power

After I’ve updated my MDEK1001 tags and anchors with Release 2, I struggle to get connection between the anchors, listener and tags. I can’t even get communication between a tag and a anchor through a double brick wall with a distance of less than a meter between the anchor an tag. I only get a position of a tag if I put 4 anchors in 1 room.

Must a listener “see” all anchors?
How can I improve the range of the anchors?
Did the default power changed with the new Release 2?
How can I cover a normal house build with bricks?
Must I install 4 anchors in a room and connect it to a RPi?

Any help or recommendations will be appreciated.

Hi Izak,

the listener needs only to see the Tags.

To improve the range try avoid the Fresnel zones. In simple words do not put Anchors/Tags too close to the wall/ground/ceiling/obstacles. If possible keep at least 30 cm from the wall/ceiling.

The Release 2 should contain correct power settings compliant with the FCC/ETSI.

I would try to find out first if the range issue is related with the Fresnel zones. Then extend the network with more anchors as needed.

If you have a larger installation then Gateway approach should be used. Listener is suitable just for a small setup where the Tags are in range with it.


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Hi leapslabs

Thank you for your reply.

I’ve build a bracket to fit my Anchors to a wall so that the distance is now over 20cm from the wall.

I’ve download the new release 2 package and unzip it, but can’t find the gateway installation guide for Raspberry Pi. I was looking at the Decawave website, but can’t find it. What is the link where I can download it?

I found the file under …/Product and Design Documents/ folder.

Regarding your answer previously, you say that the listener always must see the tags, and a Tag to Listener range is about 25m maximum, meaning the maximum cover per listener is 25m x 25m open space, how do you expand the system without a gateway if I want to use eg only 8 anchors in a house? In this example the distance between anchors is 10m and the tag is about 30m away from the listener but in range of at least 4 anchors will result that the tag wouldn’t be “seen” by the listener and can’t calculate the coordinates?

I thought that the anchors closest to the listener, communicate with the listener and collect the data of visible tags

My system works well in 1 room, but if I move the tag to another room where there is also anchors, the systems don’t display the coordinates anymore. With my Android device I must stand in the middle of the tags to receive a signal from the anchors, but my Listener is not installed in the middle of the anchors, but in reach of at least 2 anchors.

What is the importance of the placement (position) of the listener and where is the best position to mount the listener with the RPi?

Hi Izak,

The range around 25m is point to point and can be achieved in ideal condition. I.e. the Fresnel Zone is avoided, the antenna are orientated the direction with best radiation, etc. In practice this range would be shorter so e.g. the Tag would have some extra budget when moving around. In addition the coverage area is not square as you have written but more like a non-perfect ellipsoid (very simplified explanation).

The only way to have connection to all nodes in an extended area is using the Gateway. Just put there multiple Gateways so the can cover robustly the area of interest.

I think you misunderstood the Listener concept. The Listener only listen and print out the location of the surrounding Tags and/or provide them via BLE. It does not provide any other service like IoT or Configuration Data to/from the nodes. The Listener is suitable mainly for demo purpose. If you need multiple rooms then the only way is to use Gateway approach.