On-Demand Cooperation MAC Protocols with Optimal Diversity-Multiplexing Tradeoff

This paper presents access protocols with optimal Diversity-Multiplexing Tradeoff (DMT) performance in the context of IEEE 802.11-based mesh networks. The protocols are characterized by two main features: on-demand cooperation and selection of the best relay terminal. The on-demand characteristic refers to the ability of a destination terminal to ask for cooperation when it fails in decoding the message transmitted by a source terminal. This approach allows maximization of the spatial multiplexing gain. The selection of the best relay terminal allows maximization of the diversity order. Hence, the optimal DMT curve is achieved with these protocols

DMT Optimal Cooperative Protocols with Destination-Based Selection of the Best Relay

We design a cooperative protocol in the context of wireless mesh networks in order to increase the reliability of wireless links. Destination terminals ask for cooperation when they fail in decoding data frames transmitted by source terminals. In that case, each destination terminal D calls a specific relay terminal B with a signaling frame to help its transmission with source terminal S. To select appropriate relays, destination terminals maintain tables of relay terminals, one for each possible source address. These tables are constituted by passively overhearing ongoing transmissions. Hence, when cooperation is needed between S and D, and when a relay B is found by terminal D in the relay table associated with terminal S, the destination terminal sends a negative acknowledgment frame that contains the address of B. When the best relay B has successfully decoded the source message, it sends a copy of the data frame to D using a selective decode-andforward transmission scheme. The on-demand approach allows maximization of the spatial multiplexing gain and the cooperation of the best relay allows maximization of the spatial diversity order. Hence, the proposed protocol achieves optimal diversitymultiplexing trade-off performance. Moreover, this performance is achieved through a collision-free selection process

Performance evaluation of a medium access control protocol for a distributed ARQ scheme in cooperative wireless networks

A performance evaluation of a medium access control protocol for a distributed ARQ scheme in cooperative wireless networks is presented in this paper. The protocol under evaluation is the Persistent Relay Carrier Sensing Multiple Access protocol (PRCSMA). The protocol was designed to be easily integrated in standard IEEE 802.11 networks in order to increase their performance and to extend coverage. The main goals of this paper are to present and to discuss the performance evaluation of the PRCSMA under different network configurations. Computer simulations demonstrate the robustness of the protocol under different scenarios.Peer ReviewedPostprint (author’s final draft

Analysis of a distributed queuing medium access control protocol for cooperative ARQ

Postprint (published version

Outage probability of an optimal cooperative MAC protocol in Nakagami-m channels

A new cooperative access protocol is presented in the context of IEEE 802.11-based fixed ad hoc networks. The protocol achieves optimal diversity-multiplexing tradeoff thanks to two known functionalities: on-demand cooperation and selection of the best relay. The on-demand approach allows maximization of the spatial multiplexing gain. The selection of the best relay allows maximization of the spatial diversity order. The main contribution of this paper consists in the design of a proactive mechanism in order to select the best relay. The mechanism is centralized at the destination terminal. Destination terminals maintain lists of relays for all possible source terminals by overhearing ongoing transmissions. So when cooperation is needed, a destination terminal just picks the best relay for a specific source terminal in the corresponding table. Hence, collision among relay candidates is now avoided. Moreover, only terminals that can improve the direct transmission are selected. This guarantees the usefulness of relaying. This study focusses on Nakagami-m wireless channel models in order to encompass a wide variety of fading models

Persistent RCSMA: a MAC protocol for a distributed cooperative ARQ scheme in wireless networks

EURASIP Best Paper Award for the "Jounal on Advances in Signal Processing"The persistent relay carrier sensing multiple access (PRCSMA) protocol is presented in this paper as a novel medium access control (MAC) protocol that allows for the execution of a distributed cooperative automatic retransmission request (ARQ) scheme in IEEE 802.11 wireless networks. The underlying idea of the PRCSMA protocol is to modify the basic rules of the IEEE 802.11 MAC protocol to execute a distributed cooperative ARQ scheme in wireless networks in order to enhance their performance and to extend coverage. A closed formulation of the distributed cooperative ARQ average packet transmission delay in a saturated network is derived in the paper. The analytical equations are then used to evaluate the performance of the protocol under different network configurations. Both the accuracy of the analysis and the performance evaluation of the protocol are supported and validated through computer simulations.Peer ReviewedAward-winningPostprint (published version

Cooperative ARQ: A Medium Access Control (MAC) Layer Perspective

Postprint (published version

Evaluación de protocolos MAC cooperativos para sistemas de transmisión inalámbricos

Las técnicas llamadas de transmisión cooperativa son innovadoras en los sistemas de comunicaciones inalámbricos. Los sistemas de nueva generación incorporarán este tipo de comunicaciones. Este proyecto ha consistido en estudiar e implementar protocolos MAC que incluyan técnicas de transmisión cooperativa para mejorar el rendimiento de un sistema de transmisión inalámbrico, introduciendo la utilización de relays o nodos intermedios. Se analizarán las mejoras que pueden ofrecer estas técnicas de transmisión en términos de PER (Packet Error Rate), RSSI (Received Signal Strength Indication), consumo de energía de las baterías y el retardo. Se utilizarán motas CrossBow con tecnología radio IEEE 802.15.4 y sistema operativo tinyOS. El lenguaje de programación de estas motas es nesC, que es un dialecto del código C para redes de sensores y que está orientado a componentes

Evaluación de protocolos MAC cooperativos para sistemas de transmisión inalámbricos

Las técnicas llamadas de transmisión cooperativa son innovadoras en los sistemas de comunicaciones inalámbricos. Los sistemas de nueva generación incorporarán este tipo de comunicaciones. Este proyecto ha consistido en estudiar e implementar protocolos MAC que incluyan técnicas de transmisión cooperativa para mejorar el rendimiento de un sistema de transmisión inalámbrico, introduciendo la utilización de relays o nodos intermedios. Se analizarán las mejoras que pueden ofrecer estas técnicas de transmisión en términos de PER (Packet Error Rate), RSSI (Received Signal Strength Indication), consumo de energía de las baterías y el retardo. Se utilizarán motas CrossBow con tecnología radio IEEE 802.15.4 y sistema operativo tinyOS. El lenguaje de programación de estas motas es nesC, que es un dialecto del código C para redes de sensores y que está orientado a componentes