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International audience ; Underwater acoustic (UWA) sensor network deployments may be used in many applications for environmental, scientific, military, and commercial purposes. Several topologies are in use, but the most widely used topology is linear. Indeed, placing nodes on a single line offers more opportunities in terms of large coverage and high-rate services. The UWA channel is a shared medium. Thus, a medium access control (MAC) protocol is necessary, primarily to regulate and coordinate nodes' access. MAC protocol design should take into consideration large propagation delays to favor better network throughput. Performance of most developed protocols in linear topologies does not exceed 1 in terms of normalized network throughput, or equivalently, channel utilization. We explore transmission schedules in three important contexts. 1) Single collision domain with unicast traffic. In an N -node network, we develop transmission schedules achieving a normalized network throughput of 2−(2/N) . This is the best that can be done in such a context, as demonstrated using a general greedy approach combined with an exhaustive search for small-size networks. 2) Single collision domain with broadcast traffic. We propose a periodic per-node fair schedule with the shortest period. Achievable throughput in such conditions is close to N/2 . Likewise, we prove that the throughput is upper bounded by N−1 under the per-node fairness constraint. 3) Partially overlapping collision domains with unicast traffic. We consider a simple illustration of such a configuration. The proposed transmission schedule depicts a scenario where messages originate at one end of the network, and are sequentially relayed node by node (i.e., hop by hop) in the direction of the final destination located at the other end of the network. Furthermore, for all three discussed contexts, we build up computationally efficient algorithms that generate transmission schedules regardless of network size. We explore the idea of exploiting nonzero propagation ...

International audience ; Underwater acoustic (UWA) sensor network deployments may be used in many applications for environmental, scientific, military, and commercial purposes. Several topologies are in use, but the most widely used topology is linear. Indeed, placing nodes on a single line offers more opportunities in terms of large coverage and high-rate services. The UWA channel is a shared medium. Thus, a medium access control (MAC) protocol is necessary, primarily to regulate and coordinate nodes' access. MAC protocol design should take into consideration large propagation delays to favor better network throughput. Performance of most developed protocols in linear topologies does not exceed 1 in terms of normalized network throughput, or equivalently, channel utilization. We explore transmission schedules in three important contexts. 1) Single collision domain with unicast traffic. In an N -node network, we develop transmission schedules achieving a normalized network throughput of 2−(2/N) . This is the best that can be done in such a context, as demonstrated using a general greedy approach combined with an exhaustive search for small-size networks. 2) Single collision domain with broadcast traffic. We propose a periodic per-node fair schedule with the shortest period. Achievable throughput in such conditions is close to N/2 . Likewise, we prove that the throughput is upper bounded by N−1 under the per-node fairness constraint. 3) Partially overlapping collision domains with unicast traffic. We consider a simple illustration of such a configuration. The proposed transmission schedule depicts a scenario where messages originate at one end of the network, and are sequentially relayed node by node (i.e., hop by hop) in the direction of the final destination located at the other end of the network. Furthermore, for all three discussed contexts, we build up computationally efficient algorithms that generate transmission schedules regardless of network size. We explore the idea of exploiting nonzero propagation delays for linear topologies to improve network throughput. In recent UWA sensor networks, the linear topology is a fundamental component that may be used to build more complex network configurations. This study would then serve as a base for future research into this area.

International audience ; Underwater acoustic (UWA) sensor network deployments may be used in many applications for environmental, scientific, military, and commercial purposes. Several topologies are in use, but the most widely used topology is linear. Indeed, placing nodes on a single line offers more opportunities in terms of large coverage and high-rate services. The UWA channel is a shared medium. Thus, a medium access control (MAC) protocol is necessary, primarily to regulate and coordinate nodes' access. MAC protocol design should take into consideration large propagation delays to favor better network throughput. Performance of most developed protocols in linear topologies does not exceed 1 in terms of normalized network throughput, or equivalently, channel utilization. We explore transmission schedules in three important contexts. 1) Single collision domain with unicast traffic. In an N -node network, we develop transmission schedules achieving a normalized network throughput of 2−(2/N) . This is the best that can be done in such a context, as demonstrated using a general greedy approach combined with an exhaustive search for small-size networks. 2) Single collision domain with broadcast traffic. We propose a periodic per-node fair schedule with the shortest period. Achievable throughput in such conditions is close to N/2 . Likewise, we prove that the throughput is upper bounded by N−1 under the per-node fairness constraint. 3) Partially overlapping collision domains with unicast traffic. We consider a simple illustration of such a configuration. The proposed transmission schedule depicts a scenario where messages originate at one end of the network, and are sequentially relayed node by node (i.e., hop by hop) in the direction of the final destination located at the other end of the network. Furthermore, for all three discussed contexts, we build up computationally efficient algorithms that generate transmission schedules regardless of network size. We explore the idea of exploiting nonzero propagation ...

International audience ; Many marine scientific, industrial and military applications may require the deployment of underwater acoustic sensor networks for sensing and monitoring. A grid topology with multihop relaying is useful for wide area coverage as well as long distance data transmission. We investigate network architectures where data originate at one end of the grid, and are forwarded along multiple lines. We are particularly interested in transmission schedules that maximize network throughput by exploiting propagation delay to allow multiple simultaneous transmissions. We show that an optimal schedule is necessarily per-node fair, and derive the upper bound on throughput. Furthermore, we present a low-complexity algorithm to find schedules achieving the upper bound, regardless of the size of the network.

International audience ; Many marine scientific, industrial and military applications may require the deployment of underwater acoustic sensor networks for sensing and monitoring. A grid topology with multihop relaying is useful for wide area coverage as well as long distance data transmission. We investigate network architectures where data originate at one end of the grid, and are forwarded along multiple lines. We are particularly interested in transmission schedules that maximize network throughput by exploiting propagation delay to allow multiple simultaneous transmissions. We show that an optimal schedule is necessarily per-node fair, and derive the upper bound on throughput. Furthermore, we present a low-complexity algorithm to find schedules achieving the upper bound, regardless of the size of the network.

International audience ; Many marine scientific, industrial and military applications may require the deployment of underwater acoustic sensor networks for sensing and monitoring. A grid topology with multihop relaying is useful for wide area coverage as well as long distance data transmission. We investigate network architectures where data originate at one end of the grid, and are forwarded along multiple lines. We are particularly interested in transmission schedules that maximize network throughput by exploiting propagation delay to allow multiple simultaneous transmissions. We show that an optimal schedule is necessarily per-node fair, and derive the upper bound on throughput. Furthermore, we present a low-complexity algorithm to find schedules achieving the upper bound, regardless of the size of the network.

International audience ; Development and deployment of underwater acoustic (UWA) sensor networks have emerged as an efficient solution for many applications related to marine environment e.g., scientific, industrial, and military operations. The main tasks to execute are remote sensing and monitoring. Grid topology with multihop relaying is very useful, since it allows a wide area coverage as well as long distance data transmission. In this paper, we investigate architectures where sensing and monitoring data are forwarded over multiple lines independently. We are interested in transmission schedules which maximize network throughput. We prove that an optimal schedule is necessarily per-node fair. We also derive the upper bound. Furthermore, we present a low-complexity algorithm to find schedules achieving the upper bound, regardless of the size of the network.

International audience ; Development and deployment of underwater acoustic (UWA) sensor networks have emerged as an efficient solution for many applications related to marine environment e.g., scientific, industrial, and military operations. The main tasks to execute are remote sensing and monitoring. Grid topology with multihop relaying is very useful, since it allows a wide area coverage as well as long distance data transmission. In this paper, we investigate architectures where sensing and monitoring data are forwarded over multiple lines independently. We are interested in transmission schedules which maximize network throughput. We prove that an optimal schedule is necessarily per-node fair. We also derive the upper bound. Furthermore, we present a low-complexity algorithm to find schedules achieving the upper bound, regardless of the size of the network.

International audience ; Development and deployment of underwater acoustic (UWA) sensor networks have emerged as an efficient solution for many applications related to marine environment e.g., scientific, industrial, and military operations. The main tasks to execute are remote sensing and monitoring. Grid topology with multihop relaying is very useful, since it allows a wide area coverage as well as long distance data transmission. In this paper, we investigate architectures where sensing and monitoring data are forwarded over multiple lines independently. We are interested in transmission schedules which maximize network throughput. We prove that an optimal schedule is necessarily per-node fair. We also derive the upper bound. Furthermore, we present a low-complexity algorithm to find schedules achieving the upper bound, regardless of the size of the network.