MANET (Mobile Ad hoc network) [3 @1] is a wireless mobile system composed by nodes that communicate with wireless links fig.1. Its main characteristics is the absence of any fixed infrastructure, which make nodes able to self configure and self-organize for establishing communications, exchanging information and ensuring the network functionality. Also, the network size is frequently changed over time due to nodes newly joined the networks and those dynamically leaved (roaming). Today with the popularity of mobile devices (smart phones, sensor, pc.etc.) MANET is present in many military and civil fields like: room class conferences, emergency rescue operations and military control.
Fig. 1 Mobile AdHoc network (MANET)
VANET (Vehicular AdHoc Network) is a technology for managing the road traffic and providing a safety driving environment [4 @2]. The network is composed by a set of vehicles really present in the road fig.2. Vehicles communicate and exchange information among each other by using two communication modes. The first one is direct Vehicle to Vehicle communication (V2V) that automatically allows establishing communication between vehicles in the same network. The second mode is vehicle to interface (V2I) which requires the connection to a fixed infrastructure unit called RSU (road side unit). This interface allows communication between vehicles, monitor them and also provide them an access to the Internet cloud.
Fig. 2 Vehicle AdHoc network (VANET)
FANET (Flaying AdHoc Networks) is a subset of MANETs that uses the AdHoc communication in a three-dimensional plane. The network is composed by a collection of UAVs (Unmanned Aerial Vehicles) [5 @doi] able to execute a predefined mission fig.3. UAVs are small aerial vehicles equipped with sensors and smart computing devices [5 @doi]. FANET inherits the same features of MANET except that nodes can fly autonomously in the network producing higher mobility degrees. Two communication modes are distinguished: Air-to-air wireless communications (A2A) by
Fig. 3 Flaying AdHoc network (FANET)
B- Main features
Self-organized AdHoc networks introduced in this paper have some features in common. The main ones are the self organized nodes, the use of existing nodes for managing the network traffic (i.e. node acts as hosts and routers at the same time), the multi-hop rooting to transfer information and the distributed mobile system in which topology is randomly changed. Other specific characteristics make the difference between MANETs, VANETs and FANETs are listed as follow:
• The nodes used in the network: heterogeneous or homogeneous in type, nodes interacted in dynamic networks are numerous and depend to the purpose of designing the network. Vehicles, sensor devices or UAVs are the famous equipments that could be present with the existing networks.
• The environment dimension: this indicates the movements of nodes in the coverage area of the network. In some technologies nodes move close to the ground, and in others nodes are able to fly in free space.
• The speed of nodes: networks are characterized by random, height, or slow movements of nodes. This metric identifies the mobility level that changes the network topology.
• Energy of nodes: This feature differs for each dynamic network. Depending to the mission of nodes some technologies require devices with High capacity of energy, but others tolerate equipment with a low capacity of energy.
• Limited physical security: with the movement of nodes in different directions providing a physical security is challenged.