Problems with Correct Traffic Differentiation in Line Topology IEEE 802.11 EDCA Networks in the Presence of Hidden and Exposed Nodes
نویسندگان
چکیده
The problem of content delivery with a required QoS is currently one of the most important. In ad-hoc networks it is IEEE 802.11 EDCA which tries to face this problem. This paper describes several EDCA line topology configurations with mixed priorities of nodes. Detailed conclusions about the innovative results help to understand the behavior of EDCA in the presence of hidden and exposed nodes. They reveal a strong unfairness in medium access between certain nodes dependent on their placement. They prove that for short lines a frequent inversion in the throughput levels of high and low priority traffic occurs and makes reliable content exchange impossible. The importance of the strength of the exposedness and hiddenness of nodes is also discussed. Furthermore, the usefulness of the four-way handshake mechanism is argued and descriptions of the known solutions to the hidden and exposed node problems are given. Finally, novel conclusions about EDCA are provided.
منابع مشابه
Thorough Analysis of IEEE 802.11 EDCA in Ring Topology Scenarios with Hidden and Exposed Nodes
In this paper the authors present a simulation study of five different ring networks with hidden and exposed nodes in which the IEEE 802.11 EDCA function is used as the MAC protocol. The presented analysis is crucial for understanding how the theoretically simple ring topology can be degraded by the presence of hidden and exposed nodes. Configurations with equal and mixed priorities are conside...
متن کاملService Differentiation of IEEE 802.11e
The type of the applications for which Internet is being used has changed over the years. Multimedia applications, Real-time applications and Game playing require Quality of service. IEEE has proposed IEEE 802.11e, a quality of service extension to the wireless LAN standard IEEE 802.11. In this paper service differentiation ability of 802.11e is evaluated. Identical traffic is considered for al...
متن کاملService Differentiation of IEEE 802.11e
The type of the applications for which Internet is being used has changed over the years. Multimedia applications, Real-time applications and Game playing require Quality of service. IEEE has proposed IEEE 802.11e, a quality of service extension to the wireless LAN standard IEEE 802.11. In this paper service differentiation ability of 802.11e is evaluated. Identical traffic is considered for al...
متن کاملA Hidden Node Aware Network Allocation Vector Management System for Multi-hop Wireless Ad hoc Networks
Many performance evaluations for IEEE 802.11distributed coordination function (DCF) have been previouslyreported in the literature. Some of them have clearly indicatedthat 802.11 MAC protocol has poor performance in multi-hopwireless ad hoc networks due to exposed and hidden nodeproblems. Although RTS/CTS transmission scheme mitigatesthese phenomena, it has not been successful in thoroughlyomit...
متن کاملImproving QoS and security in wireless ad hoc networks by mitigating the impact of selfish behaviors: a game-theoretic approach
Selfish users are known to be a severe security threat for wireless ad-hoc networks. In particular, they can exploit mechanisms designed to assure QoS in the network. In this paper the problem of backoff misbehavior in IEEE 802.11 EDCA networks is studied using a game-theoretic approach. First, it is shown how this selfish behavior can disrupt traffic differentiation. Then, a solution is propos...
متن کامل