Distributed Opportunistic Scheduling in Multihop Wireless Ad Hoc Networks

Abstract

Abstract-In this paper, we introduce a framework for distributed opportunistic scheduling in multihop wireless ad hoc networks. With the proposed framework, one can take a scheduling algorithm originally designed for infrastructure-based wireless networks and adapt it to multihop ad hoc networks. The framework includes a wireless link state estimation mechanism, a medium access control (MAC) protocols and a MAC load control mechanism. The proposed link state estimation mechanism accounts for the latest results of packet transmissions on each wireless link. To improve robustness and provide service isolation during channel errors, the MAC protocol should not make any packet retransmissions but only report the transmission result to the scheduler. We modify IEEE 802.11 to fulfill these requirements. The MAC load control mechanism improves the system robustness. With link state information and the modified IEEE 802.11 MAC, we use BGFS-EBA, an opportunistic scheduling algorithm for infrastructured wireless networks, as an example to demonstrate how such an algorithm is converted into its distributed version within the proposed framework. The simulation results show that our proposed method can provide robust outcome fairness in the presence of channel errors.

Review of Packet Scheduling Algorithms in Mobile Ad Hoc Networks

“…In [14], algorithm concentrates on error compensation, link status estimation and fair scheduling into consideration simultaneously for distributed scheduling in multihop ad hoc networks. It has a framework, named "Robust Opportunistic Scheduling for Ad Hoc Networks" (ROSA), with which a scheduling algorithm originally designed for infrastructured wireless networks can be adapted to multihop ad hoc networks.…”

Cooperative and Opportunistic Transmission in Wireless and Mobile Ad-Hoc Networks

“…Wireless networks traditionally viewed as a source of unreliability that needs to be mitigated, recent research suggests exploiting the channel fluctuations opportunistically when and where the channel is strong [8]. At first error compensation, link status estimation and fair scheduling was not considered for wireless ad hoc networks which exploit some issues in scheduling and transmitting packets over some bad links [9]. Also error control on the source node is not useful in wireless Ad-Hoc Network [6].…”

“…The error control can be achieved in wireless ad hoc network with multiple co-operative relays [6]. As well as the ROSA framework improves retransmission technique by moving retransmission decision from MAC protocol to scheduler, also it improves the communication by the node cooperation and considering the link status [9]. A cooperative content dissemination framework (CCDF) is used to share contents among mobile users by utilizing low cost wireless connectivity as well as storage spaces efficiently [11].…”

“…By utilizing the link status information provided by ROSA the adapted algorithm performs distributed scheduling opportunistically. MAC layer blocking problem and solution, Link state estimation, Medium access abuse problem and solution, Adapting BGFS-EBA to distributed environment are covered by ROSA framework [9]. A distributed scheduling algorithm, which is inspired by a greedy algorithm in graph theory to find the maximum weighted independent set, is also used for opportunistic scheduling.…”

“…A multihop ad hoc network is an ad hoc network in which the packets of a traffic flow are relayed by one or more intermediate nodes before they reach the destination. To support different types of multimedia applications, providing various quality of service (QoS) guarantees for multihop flows is an important issue in wireless ad hoc networks [9].…”