Section: Application Domains

Wireless mesh and mobile ad hoc networks

A mobile ad hoc network is a network made of a collection of mobile nodes that gather spontaneously and communicate without requiring a pre-existing infrastructure. Of course a mobile ad hoc network use a wireless communication medium. They can be applied in various contexts:

• military;

• rescue and emergency;

• high speed access to internet.

The military context is historically the first application of mobile ad hoc networks.

The rescue context is halfway between military and civilian applications. In emergency applications, heterogeneous wireless networks have to cooperate in order to save human lifes or bring the situation back to normal as soon as possible. Wireless networks that can be quickly deployed are very useful to assess damages and take the first decisions appropriate to the disaster of natural or human origin. The primary goal is to maintain connectivity with the humans or the robots (in case of hostile environment) in charge of network deployment. This deployment should ensure the coverage of an interest area or of only some interest points. The wireless network has to cope with pedestrian mobility and robots/vehicles mobility. The environment, initially unknown, is progressively discovered and usually has many obstacles. These obstacles should be avoided. The nodes of the wireless network are usually battery-equipped. Since they are dropped by a robot or a human, their weight is very limited. The protocols supported by these nodes should be energy efficient to increase network lifetime. Furthermore, in case of aggressive environment, sensor nodes should be replaced before failing. Hence, in such conditions, it is required to predict the failure time of nodes to favor a predictive maintenance.

Mobile ad hoc network provide an enhanced coverage for high speed wireless access to the internet. The now very popular WLAN standard, WiFi, provides much larger capacity than mobile operator networks. Using a mobile ad hoc network around hot spots will offer high speed access to much larger community, including cars, busses, trains and pedestrians.