Body Channel Characterisation
The WiSAR Lab is performing a range of on-body tests as part of researching the body channel
Off the Shelf Device Tests
This set of tests measured the packet error rate in different conditions using an off the shelf device. A TmoteSky mote was placed on the hest transmitting at 0dBm and another TmoteSky acting as the receiver was placed on the right side of a belt at the waist. The Packet Error ate (PER) was measured indoors and outdoors and was measured to be less than 0.1%. When the receiver was placed on the back and the user was indoors, the PER was less than 1% but it jumped up to 20% when the user was outside, showing the significant effects of the node positions and the nature of the environment
On Body to On Body Network Characterisation
These sets of tests use a vector network analyzer to characterise the channel between two sensors placed on-body.
The tests were performed in an empty room with dimension 10.50m.x 6.70m. x 3m (and also in an outdoor free space environment), with sensors placed on the following parts of the body :
- on the chest (e.g. respiration sensor)
- on the left or right wrist
- on the right waist (e.g. a coordinator)
- on the left or right ankle
- on the front of the head (e.g. an EEG)
- on the back of the neck
For these sensor locations, we measure the path gain between these devices, with the vector network analyzer configured to measure the path gain at a single frequency (2.4Ghz) and to record the path gain every 10ms.
