Multicast Routing Protocols in Mobile Ad Hoc Networks: A Comparative Survey and Taxonomy <s> Preferred Link-Based Multicast (PLBM) Protocol <s> Routing protocols in wireless ad hoc networks experience high control overhead due to frequent path breaks that occur due to mobility of nodes, which leads to flooding of control packets throughout the network. We propose a preferred link based routing protocol that reduces flooding of control packets by selectively allowing some nodes to forward the packets using a preferred list. We propose two algorithms to compute the preferred list. The first algorithm computes the preferred list based on neighbor's degree. The second algorithm computes the preferred list based on stability information. Simulation results illustrate their performance and demonstrate their good behavior compared to other protocols. They also show that the stability based algorithm finds more stable paths while the neighbor's degree based algorithm has least control overhead. <s> BIB001 </s> Multicast Routing Protocols in Mobile Ad Hoc Networks: A Comparative Survey and Taxonomy <s> Preferred Link-Based Multicast (PLBM) Protocol <s> Existing multicast routing protocols for mobile ad hoc networks can be broadly classified into two categories, tree based protocols and mesh based protocols. Mesh based protocols have high packet delivery ratio compared to tree based protocols, but incur more control overhead. The packet delivery ratio of tree based protocols decreases with increasing mobility. This is due to the occurrence of frequent tree breaks and lack of proper tree maintenance mechanisms. These tree breaks result in frequent flooding of JoinQuery packets by the multicast group member nodes which try to get re-connected to the tree. These broadcast packets collide with the data packets and reduce the efficiency of the protocol. We propose an efficient protocol which we call as preferred link based multicast protocol (PLBM). PLBM uses a preferred link approach for forwarding JoinQuery packets. Subsets of neighbors of a node are selected using a preferred link based algorithm. These nodes, termed as preferred nodes, are only eligible for further forwarding of JoinQuery packets. We also propose a quick link break detection mechanism that locally repairs broken links. Simulation results show that our protocol performs better than other existing multicast protocols in terms of packet delivery ratio and control overhead. <s> BIB002 </s> Multicast Routing Protocols in Mobile Ad Hoc Networks: A Comparative Survey and Taxonomy <s> Preferred Link-Based Multicast (PLBM) Protocol <s> Practical design and performance solutions for every ad hoc wireless networkAd Hoc Wireless Networks comprise mobile devices that use wireless transmission for communication. They can be set up anywhere and any time because they eliminate the complexities of infrastructure setup and central administration-and they have enormous commercial and military potential. Now, there's a book that addresses every major issue related to their design and performance. Ad Hoc Wireless Networks: Architectures and Protocols presents state-of-the-art techniques and solutions, and supports them with easy-to-understand examples. The book starts off with the fundamentals of wireless networking (wireless PANs, LANs, MANs, WANs, and wireless Internet) and goes on to address such current topics as Wi-Fi networks, optical wireless networks, and hybrid wireless architectures. Coverage includes: Medium access control, routing, multicasting, and transport protocols QoS provisioning, energy management, security, multihop pricing, and much more In-depth discussion of wireless sensor networks and ultra wideband technology More than 200 examples and end-of-chapter problemsAd Hoc Wireless Networks is an invaluable resource for every network engineer, technical manager, and researcher designing or building ad hoc wireless networks. <s> BIB003
Protocol Description. PLBM BIB002 is a tree-based receiverinitiated protocol. It is an extension of the Preferred LinkBased Routing Protocol (PLBR) BIB001 . It uses only a set of links to neighboring nodes for forwarding Join Query packets (preferred links). Each node maintains two tables, a Neighbor Neighbor Table ( NNT, for local network topology information) and a Connect Table ( CT, for multicast tree information). Every node in the network periodically sends small control packets, called beacons. On receiving a beacon, a node updates the corresponding entry in its NNT. Thus, the NNT is kept up to date by means of the beacon packets. When a new member wishes to join the multicast group, it first checks its NNT to determine whether or not there are tree nodes (members, forward nodes, or multicast sources) in its NNT. If so, it sends a Join Confirm message to one of them without flooding the networks with any Join Query packet. Otherwise, it propagates a Join Query message if at least one eligible neighbor node is present in its NNT for further forwarding of the Join Query packet. The eligibility of a neighbor node to further forward the Join Query packet is determined using PLBR BIB001 . Only preferred nodes are eligible for further processing of the Join Query received. On receiving this packet, a node first checks its eligibility to forward it. If it is not eligible to do so, the packet is discarded. If an eligible node is connected to a multicast tree, it sends a Join Reply packet back to the node that originated the Join Query packet and starts a timer waiting for a Join Confirm packet from the node. Otherwise, it forwards the Join Query packet. The Join Reply packet follows the route traveled by the Join Query packet, but in the reverse direction. Figure 10 shows multicast tree initialization and construction phases in PLBM. In Figure 10 using PLBA. When nodes A and B receive a Join Query packet, they also compute their preferred neighbors using PLBA. Therefore, nodes A and B send Join Query packet to {C, D} and {E, F, G}, respectively. Nodes E and D drop the Join Query packet, because they do not have any preferred nodes. Nodes C, F, and G forward the Join Query packet to nodes K, K, and G, respectively. Eventually, the source node S receives a single Join Query packet. After that, the source node S sends the Join Reply packet through path 1 . Finally, the destination node R 2 selects the first Join Reply packet it receives and sends Join Confirm, assuming that path 1 is selected. If a node, say node R 3 , wants to join the multicast group and it has a tree node (member nodes or forwarding nodes) in its NNT, it sends a Join Confirm packet to the tree node, say node B (forwarding node), without flooding the network with the Join Query packet. However, if a node wants to join a multicast group but does not have a tree node in its NNT, it (say node R 1 ) propagates a Join Query packet to be flooded in a limited manner through the network based on PLBA.  , sends a Join Confirm packet, and joins the multicast group. Discussion. It has been reported in BIB003 that the concept of the preferred link involved in PLBM provides better adaptability and flexibility. In addition, the use of 2-hop local topology information provides efficient multicast routing. The preferred list may be based on other link or node characteristics, for example, delay, bandwidth, and stability, which enables the PLBM protocol to take into consideration the QoS requirements. Since every node in the network sends a beacon packet periodically, considerable control overhead is introduced.