4. Neighbor Discovery

While header compression is relatively efficient and lightweight, mainly due to the fact that it is stateless, the Neighbor Discovery mechanisms essential to IPv6 must also be adapted in order to insert oneself into a network and talk to one's neighbors. Unfortunately, Neighbor Discovery was designed with the Ethernet model in mind, and is merely a refinement of ARP. It is based on intensive use of multicast and assumes that the notion of link is well defined. In sensor networks, given the low transmission power, the range of a link tends to fluctuate. It's possible that when propagation conditions are favorable, a node may be accessible and then no longer be; for example, when the humidity level in the air increases. So, if a duplicate address is detected on a rainy day, the equipment will not detect an identical address and enter the network, whereas under other weather conditions, it...