Definition of Ad hoc ?

An ad-hoc (or "spontaneous") network is a local area network or other small network,
especially one with wireless or temporary plug-in connections, in which some of the network devices are part of the network only for the duration of a communications session or, in the case of mobile or portable devices, while in some close proximity to the rest of the network.

The term has been applied to future office or home networks in which new devices can be quickly added, using, for example, the proposed Bluetooth technology in which devices communicate with the computer and perhaps other devices using wireless transmission.


An Ad Hoc network is a collection of wireless mobile host forming a temporary network without the aid of any centralized administration or standard support services regularly available on the wide area network to which the hosts may normally be connected (Johnson and Maltz)

Ad hoc means no infrastructure, no planning
- Normally implies wireless, mobile, multihop
- MANET : Mobile Ad Hoc Network

Mobility
- User mobility : users communicate anytime, anywhere with anyone
- Device portability : devices can be connected anytime, anywhere to the network

Wireless : Un-tethered, no physical wire attachment

Ubiquitous : existing or being everywhere at the same time ;
- Ubiquitous network which is the widespread network