Optimal Fair Scheduling in S-TDMA Sensor Networks for Monitoring River Plumes

Underwater wireless sensor networks (UWSNs) are a promising technology to provide oceanographers with environmental data in real time. Suitable network topologies to monitor estuaries are formed by strings coming together to a sink node.This network may be understood as an oriented graph. A number of MAC techniques can be used in UWSNs, but Spatial-TDMA is preferred for fixed networks. In this paper, a scheduling procedure to obtain the optimal fair frame is presented, under ideal conditions of synchronization and transmission errors. The main objective is to find the theoretical maximum throughput by overlapping the transmissions of the nodes while keeping a balanced received data rate from each sensor, regardless of its location in the network. The procedure searches for all cliques of the compatibility matrix of the network graph and solves a Multiple-Vector Bin Packing (MVBP) problem. This work addresses the optimization problem and provides analytical and numerical results for both the minimum frame length and the maximum achievable throughput

ECS: Efficient Communication Scheduling for Underwater Sensor Networks

TDMA protocols have attracted a lot of attention for underwater acoustic sensor networks (UWSNs), because of the unique characteristics of acoustic signal propagation such as great energy consumption in transmission, long propagation delay and long communication range. Previous TDMA protocols all allocated transmission time to nodes based on discrete time slots. This paper proposes an efficient continuous time scheduling TDMA protocol (ECS) for UWSNs, including the continuous time based and sender oriented conflict analysis model, the transmission moment allocation algorithm and the distributed topology maintenance algorithm. Simulation results confirm that ECS improves network throughput by 20% on average, compared to existing MAC protocols

A Multilevel Scheduling MAC Protocol for Underwater Acoustic Sensor Networks(UASN)

Underwater acoustic sensor networks (UASNs) have attracted great attention in recent years and utilizes as a part of oceanic applications. This network has to deal with propagation delay, energy constraints and limited bandwidth which are strenuous for designing a Medium Access Control (MAC) protocol for underwater communication. There also exists an idle channel listening and overhearing problem which sets down the energy into starvation in the contention-based MAC protocols. Alternatively, lengthy time slots and time synchronization equated by schedule-based MAC protocols, outcomes the variable transmission delay and degrades the network performances. To iron out these problems, we propose a cluster-based MAC protocol, tagged as Multilevel Scheduling MAC (MLS-MAC) protocol for UASN in the paper. The cluster head is a decision maker for packet transmission and aids to inflate the lifetime of sensor nodes. To reinforce the channel efficiency, the multilevel scheduling in data phase is initiated with two queues depending on the applications fixed by the cluster head. The simulation result shows that the MLS-MAC has increased the network throughput and has decreased energy consumption

Transmission Scheduling Technique for A Propagation transfer using Sensing Protocol Under water Acoustic Wireless Sensor Networks.

 As detector nodes square measure typically powered devices, the vital aspects to face concern the way to cut back the energy consumption of nodes, so the network lifespan may be extended to cheap times. Mobile underwater networks with acoustic communications square measure faced with many distinctive challenges like high transmission power utilization, giant propagation delay and node quality. In which Protocol multichip wireless network that uses multiple channel and dynamic channel choice technique. The comparison is conceded out by means that of analytical models, that square measure wont to confine the activities of a node that acts in line with either thought-about specifically for the underwater acoustic surroundings. The delay-aware opportunist transmission planning rule has been principally designed for underwater mobile detector networks. It uses passively obtained native info to reinforce the probabilities of synchronic transmissions whereas reducing collisions. Together with that, a straightforward performance mechanism that allows multiple outstanding packets at the sender facet, facultative multiple transmission sessions has been projected, that successively considerably improves the turnout. Every node learns neighboring node’s propagation delay info and their expected transmission schedules by passively overhearing packet transmissions through the institution of the new developed Macintosh protocol referred to as DOTS. This protocol principally aspires to attain higher channel utilization by harnessing each temporal and spatial recycle. The simulation results exemplify that DOTS provides truthful, medium access even with node quality. Thence this protocol additionally saves transmission energy by avoiding collisions whereas increasing turnout. It additionally achieves a turnout many times over that of the Slotted FAMA, whereas providing connected savings in energy. understanding that protocol is additional suited to given network setting and square measure expected to be of facilitate in planning novel protocol that presumably surmount presently out there solutions. Node monitor native underwater activities and report collected detector knowledge exploitation acoustic multi-hop routing to alternative mobile nodes for collaboration or just to a far off knowledge assortment center