Telecommun Syst (2012) 50:181–198 DOI 10.1007/s11235-010-9397-9 Fair TDMA scheduling in wireless multihop networks Dimitrios J. Vergados · Aggeliki Sgora · Dimitrios D. Vergados · Demosthenes Vouyioukas · Ioannis Anagnostopoulos Published online: 11 December 2010 © Springer Science+Business Media, LLC 2010 Abstract In wireless multihop networks, communication between two end-nodes is carried out by hopping over mul- tiple wireless links. However, the fact that each node has to transmit not only its own traffic, but also traffic on be- half of other nodes, leads to unfairness among the commu- nication rates of the nodes. Traditional Carrier Sense Mul- tiple Access/Collision Avoidance (CSMA/CA) based me- dia access control does not work satisfactory in a multi- D.J. Vergados School of Electrical and Computer Engineering, National Technical University of Athens, 7, Iroon Polytexneiou St., Zografou, 157 73 Athens, Greece e-mail: djvergad@telecom.ntua.gr A. Sgora · D.D. Vergados · D. Vouyioukas · I. Anagnostopoulos Department of Information and Communication Systems Engineering, University of the Aegean, 832 00 Karlovassi, Samos, Greece A. Sgora e-mail: asgora@aegean.gr D.D. Vergados e-mail: vergados@aegean.gr D. Vouyioukas e-mail: dvouyiou@aegean.gr I. Anagnostopoulos e-mail: janag@aegean.gr D.D. Vergados ( ) Department of Informatics, University of Piraeus, 80, Karaoli & Dimitriou St., 185 34 Piraeus, Greece e-mail: vergados@unipi.gr I. Anagnostopoulos Department of Computer Science and Biomedical Informatics, University of Central Greece, 2-4, Papasiopoulou St., 35100 Lamia, Greece e-mail: janag@ucg.gr hop scenario, since an intended target of a communication may be subject to mutual interference imposed by concur- rent transmissions from nodes, which cannot directly sense each other, thus causing unfair throughput allocation. Al- though Time Division Multiple Access (TDMA) seems to be a more promising solution, careful transmission schedul- ing is needed in order to achieve error-free communication and fairness. Several algorithms may be found in the liter- ature for scheduling TDMA transmissions in wireless mul- tihop networks. Their main goal is to determine the opti- mal scheduling, in order to increase the capacity and reduce the delay for a given network topology, though they do not consider the traffic requirements of the active flows of the multihop network or fairness issues. In this paper, we pro- pose a joint TDMA scheduling/load balancing algorithm, called Load-Balanced-Fair Flow Vector Scheduling Algo- rithm (LB-FFVSA). This algorithm schedules the transmis- sions in a fair manner, in terms of throughput per connec- tion, taking into account the communication requirements of the active flows of the network. Simulation results show that the proposed algorithm achieves improved performance compared to other solutions, not only in terms of fairness, but also in terms of throughput. Moreover, it was proved that when a load balancing technique is used, the performance of the scheduling algorithm is further improved. Keywords Wireless multihop network · Fairness · Load balancing · TDMA scheduling 1 Introduction Wireless multihop networks are formed by a set of nodes, where communication between two-end nodes is carried out by hopping over multiple short wireless links. In such a net- work, each node has to send/receive packets to/from adja-