Collision Tolerant and Collision Free Packet Scheduling for Underwater Acoustic Localization

Abstract

Abstract-This article considers the joint problem of packet scheduling and self-localization in an underwater acoustic sensor network with randomly distributed nodes. In terms of packet scheduling, our goal is to minimize the localization time, and to do so we consider two packet transmission schemes, namely a collision-free scheme (CFS), and a collision-tolerant scheme (CTS). The required localization time is formulated for these schemes, and through analytical results and numerical examples their performances are shown to be dependent on the circumstances. When the packet duration is short (as is the case for a localization packet), the operating area is large (above 3 km in at least one dimension), and the average probability of packet-loss is not close to zero, the collision-tolerant scheme is found to require a shorter localization time. At the same time, its implementation complexity is lower than that of the collision-free scheme, because in CTS, the anchors work independently. CTS consumes slightly more energy to make up for packet collisions, but it is shown to provide a better localization accuracy. An iterative Gauss-Newton algorithm is employed by each sensor node for self-localization, and the Cramér Rao lower bound is evaluated as a benchmark.

A survey on deployment techniques, localization algorithms, and research challenges for underwater acoustic sensor networks

“…They take into account a number of factors, including the network topology, signal propagation models, device capabilities, and energy requirements, as localization accuracy depends on many factors including noise, propagation losses, fading, the number of anchor nodes, the constellation of the anchor nodes, and relative position of the node to be localized. In addition, scheduling mechanism and period affects the localization accuracy and, different from the others, is an adjustable parameter …”

“…In addition, scheduling mechanism and period affects the localization accuracy and, different from the others, is an adjustable parameter. 34 The localization algorithms using anchor nodes can be broadly classified into 2 main categories: range-free algorithms or range-based algorithms. On the other hand, based on the processing type, the localization algorithms can be grouped under 2 categories, distributed and centralized localization algorithms, respectively.…”

Hybrid Localization Approach for Underwater Sensor Networks

“…In this paper, we assume that the contention-based MAC protocol (e.g., random access) is adopted for communications. In [19], a collision-tolerant packet scheduling was proposed for underwater acoustic localization. They assumed that, during a localization period, the reference nodes transmit randomly, for example, according to a Poisson distribution with an average transmission rate of packets per second.…”

“…They assumed that, during a localization period, the reference nodes transmit randomly, for example, according to a Poisson distribution with an average transmission rate of packets per second. We will apply and evaluate the collision-tolerant algorithm described in [19] with our scheme and report the results in a future paper.…”

“…Collision-tolerant packet scheduling [19] can be exploited to achieve a desired probability of successful self-localization for a given number of anchors, while and the minimum localization time can be determined. (4) Initially, only surface buoys and anchor nodes can fix their locations using GPS, a GPS intelligent buoy system, or other means.…”