Now-a-days any time anywhere connectivity was needed, which can be achieved by Mobile Ad hoc networks (MANET). Infrastructure less, self-organizing networks was called MANET. Nodes in a MANET can act as routers, able to forward packets to other nodes, within its transmission region. Designing a routing protocol for such a dynamic networks was a challenging task, due to frequent link failure, limited battery power, and mobility.
Huge number of routing protocols has been proposed for MANET , different Criteria were used to classify those protocols. Most important criteria’s are,
1. Route discovery
2. Number of routes that are computed between source and destination.
Establishing the path between source and destination was called route discovery, as per this idea, routing protocols are classified into
1. Proactive or Table driven
2. Reactive or On demand
3. Hybrid Routing
Proactive protocols uses table to maintain the overview of the network topology, these table should be updated when ever there is a change in network topology (e.g. OLSR ).
In reactive protocols route request is sent on demand i.e if a node want to sent data to another node, during that time route request was broadcast , once response came from destination data transfer will happen (e.g. Ad hoc On Demand Destination Vector Routing AODV , Dynamic Source Routing (DSR )).
Hybrid protocols uses the advantage of both proactive and reactive protocols (e.g Zone Routing Protocols (ZRP ), Zone based Hierarchical Link state (ZHLS )).
Number of routes
Another important routing criterion was the number of routes that are computed between the source and destination. As per this criteria Routing Protocols was classified as,
1. Single path Routing
2. Multipath Routing
Single path Routing protocol will develop a single path between the source and destination. Link failure and node failure can happen frequently
in Ad hoc network due to mobility, so there is a need for multiPath routing.
More than one path will be established between the source and destination, if there is a failure in any one path, the network can able to survey with the help of the other path.
Many multiPath routing protocols were proposed for Ad hoc networks . The main goal of these multipath routing protocols was to improve Quality of Service (QoS). Multiple Paths that are found by these protocols can be used as
1. Backup Route in case of primary route failure.
2. Parallel data transmission through multiple paths.
These multipoint routing protocols was categorized as follows,
This can be further classified into,
1. Node disjoint
2. Link- disjoint
Form the name it self it was clear that, the path that are formed based on this method wont share any nodes. Most of the researcher prefers node disjoint, since if there was a failure in any one node...