A Bandwidth Reservation QoS Routing Protocol for Mobile Ad Hoc Networks

Abstract

The advancement in wireless communication and economical, portable computing devices have made mobile computing possible. One research issue that has attracted a lot of attention recently is the design of mobile ad hoc network (MANET). A MANET is one consisting of a set of mobile hosts which can communicate with one another and roam around at their will. No base stations are supported in such an environment. Due to constraints such as battery power, transmission distance, and channel utilization, a mobile host may not be able to communicate directly with all other hosts in a single-hop fashion. In this case, a multi-hop scenario occurs, where packets may need to be relayed by several intermediate hosts before reaching their destinations. Applications of MANETs occur in situations like battlefields and major disaster areas, where networks need to be deployed immediately but base stations or fixed network infrastructures are not available. Since MANET is characterized by its fast changing topology, extensive research efforts have been devoted to the design of routing protocols for MANETs (Haas & Pearlman, 1998; Johnson et al., 2002; Liao et al., 2001; Perkins & Bhagwat, 1994; Perkins et al., 2002; Royer & Toh, 1999; Wu & Li, 2001). These works only concern with shortest-path routing and the availability of multitude routes in the MANET's dynamically changing environment. So only best-effort data traffic is provided. Issues related to quality-of-service (QoS) requirements, such as delay and bandwidth bounds, are less frequently addressed. This paper considers the problem of searching for a route of a given bandwidth in a MANET. This problem has been addressed by several works in the literature. References (Chen & Nahrstedt, 1999; Liao et al., 2002) have discussed this problem by assuming quite an ideal model that the bandwidth of a link can be determined independently of its neighboring links. This is untrue if all mobile hosts share a single common channel, or one needs to assume a costly multi-antenna model where a host can send/receive using several antennas simultaneously and independently. A less stronger assumption made in (Lin, 2001; Lin & Liu, 1999) is the CDMA-over-TDMA channel model, where the use of a time slot on a link is only dependent of the status of its one-hop neighboring links. Reference (Stojmenovic et al., 2000) addresses QoS routing with delay and bandwidth constraints, but still no specific channel model is accounted. In this paper, we assume a simpler TDMA model on a single common channel shared by all hosts. So it is inevitable to take the radio interference problems into consideration. We consider the bandwidth reservation problem in such environment. A route discovery