Wireless Networks Based on WiFi and Related Technologies

Ad Hoc Wireless Networks

An ad hoc wireless network is an impromptu network formed by several wireless devices, such as PDAs, laptops, and phones, without relying on an existing network infrastructure (Perkins, 2000). These devices (denoted as nodes) may be mobile and use a common wireless technology such as WiFi. To facilitate communication among the nodes that are not directly in the radio range of one another, the other nodes act as intermediate routers, just like routers in the Internet. Such networks are useful in military combat situations, where a group of soldiers must be connected to exchange information, or in emergency rescue operations, where there is no network infrastructure or the existing infrastructure has been destroyed. Because of frequent topology changes due to node mobility and due to wireless interference, the existing networking software used for the Internet is not suitable for these ad hoc networks. Consequently, extensive research on routing protocols and transport protocols has been conducted to make ad hoc networks suitable for general-purpose use.