An ad hoc network is a decentralised wireless network. An ad hoc network works by using nodes to transmit data instead of the usual routers or access points used by fixed wireless networks. They can also use flooding to forward information. An ad hoc network is usually a set of networks in which all the devices have the same status within the network and are able to connect with any other ad hoc network within range.
The advantage of an ad hoc network, because it is decentralised, is that it can be used when central nodes are not reliable. Although they have not been reached yet, theoretical limits do exist for this type of activity. As they are easy to set up quickly ad hoc networks are very useful in crises such as military conflict or natural disasters.
An ad hoc network consists of nodes connected by links. Links are influenced by the nodes. Factors affecting the nodes are things such as transmitter and computing power as well as the reliability of the network, the signal strength or loss of signal and so on. A path is created when a series of links connects two nodes. The nodes must be able to connect to one another (or link) in order for the data to be transmitted.
Normally one or two paths are used between nodes but when flooding is used then all or most of the paths will be used. Sometimes there is interference between nodes in an ad hoc network because they are all competing for access to a shared wireless medium, this can be rectified by using cooperative wireless communications.
As all the nodes compete for connectivity there can be a problem in ad hoc networks with predicting the different situations which might occur. Trying to predict these occurrences becomes very important and parameter sweeping along with what-if analysis are vital for achieving this.