Wireless Ad hoc and Sensor Networks

The contents shown on this page will be based on the Book "Wireless Ad hoc and Sensor Networks: Theory and Applications" by Carlos De Morais Cordeiro and Dharma P Agrawal

Wireless Ad hoc Network Definition: 

Collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration.

Difference between infrastructure based and infrastructure-less networks:

Cellular Network: We have recently been used to hear the term 3G, 4G, LTE etc. during using our mobile phones. These all networks are based on an infrastructure. In such type of networks, the user equipment i.e. the mobile handset is connected with a base station tower to provide us the voice and data service as illustrated bellow. 

Ad hoc Networks: Ad hoc networks, on the other hand don’t have any infrastructure to support user equipment for communications. This is a type of network where the nodes by themselves establish an autonomous and temporary network without any help from somewhere else.

In an Ad hoc network, message is transmitted through store-and-forward manner by each intermediate node from source to destination as shown in following figure.

In case a node leaves its place and moves somewhere else, this change must be known to all the nodes in the network.

Some of the important characteristics of wireless ad hoc networks are:

• Nodes (MHs) are connected through wireless links

• The nodes (MHs) are autonomous

• No infrastructure (like base station or access points)

• No central Authority

• Peer-to-peer based

• Hop by hop transmission

• Dynamically changing Topology

• Random Multi-hop Graph

• Energy as well as bandwidth-constrained

• capacity not fixed