Abstract
Previous quality-of-service (QoS) multicasting/routing algorithms in mobile ad hoc networks (MANETs) resolved bandwidth-contented routes for QoS applications. However, without considering the two-hop neighborhood, they suffer two bandwidth-violation problems, namely, the hidden route problem (HRP) and the hidden multicast route problem (HMRP). HRP may occur when a new flow is allowed and the unaware bandwidth requirement of nodes in the two-hop neighborhood has existed. HMRP may occur when bandwidth requirements of multiple new adjacent flows are allowed currently. Although the bandwidth-satisfied multicast tree in MANETs to solve both two bandwidth violation problems has been proposed, it floods quantities of control messages to collect information of all nodes for establishing a multicast tree. Therefore, we propose a novel algorithm to construct a multicast tree based both on the information in two-hop neighborhood tables to roughly estimate the bandwidth requirement with fewer control messages, and on a relay-sharing concept to choose a relay covering as many flows as possible. The proposed algorithm avoids two bandwidth violation problems and reduces the quantity of control messages. The NS-2 simulation results show that our algorithm not only obtains the high integrity of multicast trees and the high throughput, but also significantly reduces the amount of control messages and the power consumption.