MAC-Layer Research

Within the group research in to the MAC-Layer has focused on two areas, improving energy consumption in high capacity sensor networks and understand the impact of optical fibre transmission on wireless MAC.

In the area of Sensor networks our work has considered distributed MAC-layer coordination to develop new approaches to distributed coordination of data-intensive communications between wireless sensor nodes. In particular, the topics of distributed synchronization, desynchronization, and the associated energy consumption of the steady-state operation are studied in detail.
We have also consider interactions between the Physical and MAC layer to increase energy efficiency in high-load environments and when nodes are required to join the network. We have implemented, in hardware, MAC controlled, adaptive spreading codes to adjust transmission bandwidth based on requirements and channel conditions.
Our main contributions are:
  • establishing for the first time the expected time for convergence to distributed time-division-multiple-access (TDMA) operation under the two main desynchronization models proposed in the literature and validating the derived estimates via a real-world implementation [1,2]
  • proposing the extension of the main desynchronization models towards multi-channel operation; this is achieved by extending the concept of reactive listening to multi-frequency operation [1].
  • proposed a low-overhead MAC protocol utilising adaptive spreading code length feature in the practical system level, and presented the first experimental evaluation of the network performance, which is able to deliver 139% more of the throughput while saving more than 50% of the power consumption [3,4].
  • analyzing the energy consumption model for the distributed TDMA approach under the different transmission PDF and the variety of the type of the production data (work in progress).
Within Radio over Fibre (RoF) networks we produced the first comprehensive study of the impact of the delay incurred by optical distribution of wireless (WiFi) signals. Based on experimentally validated simulation and mathematical analysis, the work has shown that although transport of the physical layer is possible over may 10s of km, the MAC layer imposes significant constraints on the possible distance [5].

Academics involved in the theme:

Representative publications:

  1. D. Buranapanichkit and Y. Andreopoulos, "Distributed time-frequency division multiple access protocol for wireless sensor networks," IEEE Wireless Communications Letters, vol. 1, no. 5, pp.440-443, Oct. 2012.
  2. G. Smart, R. Surace, N. Deligiannis, V. Loscri, G. Fortino and Y. Andreopoulos, "Decentralized time-synchronized channel swapping for wireless sensor networks," Poster presented in 11th European Conference on Wireless Sensor Networks (EWSN 2014).
  3. F. Qin, J.E. Mitchell, "AS-MAC: Utilising the Adaptive Spreading Code Length for the MAC Protocol Design of WSNs", ACM Transactions on Sensor Networks Volume 10, Issue 1, Scheduled for publication February 15, 2014
  4. F. Qin, J. Mitchell, "Analyses of MAC Performance for Multi-Carrier based Wireless Sensor Networks", in 11th IEEE International Workshop on Wireless Local Networks (WLN), 2011.
  5. B. Kalantari-Sabat, M. Mjeku, N.J. Gomes, and J.E. Mitchell Performance impairments in single-mode radio-over-fiber systems due to MAC constraints. Journal of Lightwave Technology , 26 (15) pp. 2540-2548, 2008 (