Overview on Ad Hoc networks Localization

摘要

Positioning a node in wireless Ad-Hoc networks is one of the most interested research areas in recent years. Many methods have been proposed to locate a node. GPS is one of the equipments which has been widely used for positioning service. But, in many ad hoc networks, such as most sensor networks, due to very small size of nodes, there is no room to use GPS. So, some methods have been introduced for sensor networks to locate themselves without a GPS. Also in Vehicular Ad-Hoc networks in which the nodes are considered as vehicles, They move very fast in streets and highways, so to have a safe and fast transport system, any vehicle should know where a traffic problem , such as a broken vehicle occurs. Vehicle can use a GPS receiver to determine its position. But, all vehicles have not been equipped with GPS or they can not receive GPS signals in some places such as inside of a tunnel. In these situations, the vehicle should use a GPS free method to find its location. In this paper, some of the most popular localization techniques have been reviewed, and the best situations which they can be used have been suggested.