Chapter 3
RELATED WORK
This chapter explores the idea of explicit multicast in MANETs, by discussing the most
important explicit routing algorithms for MANETS found in the literature to date. This
chapter will start with the general idea about explicit multicast in MANETs then explains
thoroughly these routing algorithms in terms of their strength and their drawbacks.
3.1 Introduction
In previous chapter, multicast protocols designed for MANETs were discussed. These
protocols follow the concepts of the traditional multicast protocols; i.e distributed multicast
routing state maintenance and shared group membership management. These protocols if
applied for use with small groups within the network may become more complex and less
efficient.
To solve this issue, recently there has been a shift towards the stateless multicast routing
protocols for small group networks and for MANETs. Some of these protocols were
developed to avoid any multicast routing state to be maintained by routers. The multicast
data is encapsulated into a unicast packet and transmitted among end receivers. In other
protocols a destination list is placed in the packet header and transmitted toward the
destinations using the underlying unicast routing protocol.
The next sections will describe some protocols with details that fall into the scope of explicit
multicast for static networks and for ad hoc networks used for small groups.
34