A Dynamic Range Resource Reservation Protocol for QoS Support in Wireless Networks

Abstract — Mobile ad hoc networks (MANETs) provide a powerful and dynamic platform to enable mobile computers to establish communications without an existing infrastructure. In order to provide support for multimedia applications, Quality of Service (QoS) support becomes an important component in their design. Research is being conducted to design routing protocols in MANETs that contain QoS support features and capabilities. However, the research in this area is still in its early stages. In this paper, we present a dynamic range bandwidth reservation protocol for TDMA-based MANETs. In this protocol, a source node S, that needs to send data, sends a request message (QREQ) to reserve a QoS path to the desired destination node D. In the reservation message, the source node specifies a dynamic range [bmin, bmax] of the number of slots needed to transmit the data. The intermediate nodes along the path try to reserve a number of slots, bcur, that is equal to the maximum number of slots that are “available ” within this range (bmin ≤ bcur ≤ bmax). The protocol also permits intermediate nodes to dynamically “downgrade ” existing paths that are functioning above their minimum requirements in order to allow the successful reservation for the maximum number of requested paths. When the network traffic load is later decreased, the existing paths are able to be “upgraded” to function with higher bandwidth requirements that are close or equal to the maximum desired level (bmax). This allows the network to admit new QoS paths instead of denying such requests by allowing for “graceful degradation ” of other paths. The paper also presents several optimization techniques which are designed to increase the efficiency and throughput of the network. This protocol allows a higher level of flexibility in providing and maintaining QoS support in MANETs