21-05-2013, 11:53 AM
Routing in mobile ad-hoc networks (MANETs)
Routing in mobile.pdf (Size: 1.16 MB / Downloads: 33)
WHAT IS A MANET ?
A MANET can be defined as a system of autonomous mobile nodes that
communicate over wireless links with out any preinstalled infrastructure.
WHAT ARE THE APPLICATIONS OF MANETs ?
MANETs are useful in places that have no communications infrastructure
or when that infrastructure is severely damaged.Typical applications are
• emergency rescue operations.
• disaster relief efforts.
• low enforcement.
• military operations.
Types of MANET Routing Algorithms:
1 ) Based on the information used to build routing tables :
• Shortest distance algorithms : algorithms that use distance information to
build routing tables.
• Link state algorithms : algorithms that use connectivity information to
build a topology graph that is used to build routing tables.
2 ) Based on when routing tables are built:
• Proactive algorithms : maintain routes to destinations even if they are not
needed .
• Reactive algorithms : maintain routes to destinations only when they are
needed .
• Hybrid algorithms : maintain routes to nearby nodes even if they are
not needed and maintain routes to far away nodes only when needed
Multimedia support in Mobile Wireless Networks (MMWN).
A hierarchal routing algorithm that takes the QoS requirements into account in
route selection. It mimics the cellular phone systems by selecting few nodes to
work as dedicated router for others.
2- each group selects a cell-head and a location manager LM.
1- nodes arrange themselves in groups (cells).
3- cell heads arrange themselves in higher-level groups and select new heads
for the groups (at the highest level there is only one group).
4- starting at the highest level, members of the same group
exchange the link state information (including
QoS info.) with each other.
5- after getting link state information from its peers,
every cell head informs the heads of lower level
groups belonging to it. So, the heads of level-0
groups can create complete topology map.
6- LM nodes are the only nodes that know about the
affiliation of other nodes .