In 2014 we implemented an HTTP/web interface to the sensor nodes to test how much easier they would be to manage. This was successful but the large number of packets exchanged made it slow (not surprising).
In 2015 we are testing CoAP instead – as it is essentially a compressed binary form of HTTP – and only uses UDP packets – so there are far fewer radio exchanges. Initial tests in the lab with our CC1120 868MHz driver show it is very efficient – and we are now porting large parts of our code to use it. We will still be using Protocol Buffers – as they are also small binary compressed objects for data – so we should have the best of both worlds!