Localization Packet Scheduling for Underwater Acoustic Sensor Networks

Abstract

Medium access control (MAC) determines how sensor nodes share the channel for packet exchanging. To obtain the maximum network efficiency for accomplishing a specific task, the network has to adapt its parameters accordingly. In other words, different MAC protocols are required for different tasks. Localization is a crucial task of an underwater acoustic sensor network (UASN) which requires multiple packet exchanges. This article concerns the problem of designing a MAC protocol for a UASN which efficiently schedules the localization packets of the anchors. Knowing the relative positions of the anchors and their maximum transmission range, the scheduling protocol takes advantage of the long propagation delay of underwater communications to minimize the duration of the localization task. First, we formulate the concept of collision-free packet transmission for localization, and we show how the optimum solution can be obtained. Furthermore, we model the problem as a mixed integer linear program both in single-channel and multi-channel scenarios. Then, we propose two low-complexity algorithms, and through comprehensive simulations we compare their performances with the optimal solution as well as with other existing methods. Numerical results show that the proposed algorithms perform near optimum and better than alternative solutions.

An Overview on Current Researches on Underwater Sensor Networks: Applications, Challenges and Future Trends

“…Furthermore, they proposed two algorithms with low-complexity and they compare it with the optimal solution as well as other existing methods. Based on simulation result their proposed method has shown performance close to optimum [8]. Generally challenges in underwater acoustic sensor networks include gradual propagation of acoustic waves, bounded bandwidth, immense and irregular propagation delay, ambient noise and transmission loss.…”

“…For acoustic UWSN localization it is a vital task which requires multiple packet exchanges. Ramezani and Leus concerned the problem of designing a MAC protocol for an underwater acoustic sensor network which efficiently schedules the localization packets of the anchors [8]. Scheduling protocol can minimized propagation delay for localization duration by knowing anchors position and their maximum transmission ranges.…”

Optimal Scheduling for Interference Mitigation by Range Information

“…This is discussed further in Section III. Broadcast schedule construction for a partially connected network for localization tasks is discussed in [16], which allows transmissions on distinct sub channels. A special case of this formulation with a single channel construction can be considered for solving the problem considered in this paper.…”

“…If we consider a configuration of [16] for the B-MAC broadcast packet scheduling problem, with only anchors in a fully-connected single-channel configuration, then the proposed B-MAC scheduling problem is similar to the optimization problem of section IV-A. However, they are not exactly the same.…”

“…However, they are not exactly the same. For example, the constraint (7) in [16], is more stringent as it ensures that the the acoustic signals in the UWA network does not collide in the space between anchors nodes. This is not applicable for electromagnetic wave based WSN networks as there is no separation between the anchor-node and ordinary sensor-node in the system and only interference at all the node locations need to be nulled.…”