Dissertation projects involving Zigbee

I’m a 3rd year networking and security student in the UK.
Dissertation time has come, and the choice on what to do it is pretty hard. I don’t want to make a bad topic choice, and would like any input on what other people think would make a good project.

I chose zigbee > xbee 1/2 due to the versatility.
My initial thoughts were to do something that has not been overdone, and is at dissertation level…
The current pipeline idea is smart parks, a mesh network of conservation monitoring devices, such as temp, water levels, counters, livecam*, stuff like that, and relay the data to a db, then webserver in a nice GUi.
Is this at dissertation level?

Please give any input and ideas that may make a decent project.