Underwater acoustic communication (UWAC) is often the only viable solution to establish an ad hoc underwater communication network. The specific features of UWAC, arising from the physics of underwater acoustics, make the design of resource-efficient media access control (MAC) protocols important as well as challenging. In this paper, we tackle this task considering ad hoc UWAC networks that support high-traffic broadcast communication. To this end, we propose the application of the spatial reuse concept and the exploitation of direct sequence spread spectrum used at the UWAC physical layer to obtain a new hybrid spatial reuse time-division multiple-access (HSR-TDMA) protocol. By tracking the time-varying network topology, our protocol adaptively optimizes the set of active communication nodes and overcomes problems of UWAC networks such as the nearfar problem, flickering, and formation of islands. Pertinent performance parameters, namely network availability, message reliability, and transmission rate, are analyzed for the proposed protocol. Evaluation of these analytical performance expressions demonstrates the significant advantages of HSR-TDMA over commonly used conventional TDMA for broadcast UWAC networks. We also report performance results for both the HSR-TDMA and the conventional TDMA protocol from a sea trial at the Haifa harbor, which corroborate the results obtained from the analysis.
Bibliographical noteFunding Information:
Manuscript received February 11, 2010; revised September 27, 2010; accepted January 13, 2011. Date of publication May 12, 2011; date of current version May 27, 2011. This work was supported by the National Sciences and Engineering Research Council (NSERC) of Canada through a Vanier Scholarship and a Strategic Project Grant. Parts of this work were presented at the IEEE International Workshop on Underwater Networks (WUnderNet), Cape Town, South Africa, May 23–27, 2010. Associate Editor: M. Stojanovic.
- Underwater acoustic communication (UWAC)
- broadcast networks
- media access control (MAC)
- spatial reuse
- time-division multiple access (TDMA)
ASJC Scopus subject areas
- Ocean Engineering
- Mechanical Engineering
- Electrical and Electronic Engineering