Scheduling In Ad-hoc Networks Research Articles

A Novel Deep Energy Efficient Hello Packet Scheduling for Ad Hoc Networks in Unmanned Aerial Vehicles

Sustainable development economically viable in the aerial adhoc network (AANET) sector has become a centre of worldwide attention. The challenge here is combating the network performance and expanding lifetime time by proposing the deep hello packet scheduling heuristic.

RMTS: A Novel Approach to Transmission Scheduling in Ad Hoc Networks by Salvaging Unused Slot Transmission Assignments

In mobile ad hoc networks (MANETs) there is no centralized supervision over the network operations. In such networks, it is imperative to have protocols that are implemented locally in a distributed manner. To achieve high network performance utilizing only the wireless channels a distributed transmission-scheduling medium-access control (MAC) protocol is desirable. This type of protocol can guarantee a certain level of quality of service (QOS) and works well in congested networks. However, the transmission schedules are often decided in advance and if a node does not have a packet to transmit in its assigned slot then the slot is unused. We propose a protocol called recovering minislots transmission scheduling (RMTS) that salvages these unused transmission slots that would have otherwise been wasted. We show that the proposed protocol produces significant improvements in network performance over traditional transmission-scheduling approaches.

Opportunistic Channel Scheduling for Ad Hoc Networks with Queue Stability

AbstractIn this paper, a distributed opportunistic channel access strategy in ad hoc network is proposed. We consider the multiple sources contend for the transmission opportunity, the winner source decides to transmit or restart contention based on the current channel condition. Owing to real data assumption at all links, the decision still needs to consider the stability of the queues. We formulate the channel opportunistic scheduling as a constrained optimization problem which maximizes the system average throughput with the constraints that the queues of all links are stable. The proposed optimization model is solved by Lyapunov stability in queueing theory. The successive channel access problem is decoupled into single optimal stopping problem at every frame and solved with

An Optimal CDS Construction Algorithm with Activity Scheduling in Ad Hoc Networks.

A new energy efficient optimal Connected Dominating Set (CDS) algorithm with activity scheduling for mobile ad hoc networks (MANETs) is proposed. This algorithm achieves energy efficiency by minimizing the Broadcast Storm Problem [BSP] and at the same time considering the node's remaining energy. The Connected Dominating Set is widely used as a virtual backbone or spine in mobile ad hoc networks [MANETs] or Wireless Sensor Networks [WSN]. The CDS of a graph representing a network has a significant impact on an efficient design of routing protocol in wireless networks. Here the CDS is a distributed algorithm with activity scheduling based on unit disk graph [UDG]. The node's mobility and residual energy (RE) are considered as parameters in the construction of stable optimal energy efficient CDS. The performance is evaluated at various node densities, various transmission ranges, and mobility rates. The theoretical analysis and simulation results of this algorithm are also presented which yield better results.

Balancing Throughput and Fairness for Concurrent Flows Based on Per Flow Scheduling in Ad Hoc Networks

The focus of this paper is to present an efficient scheduling mechanism for the queue maintained by an intermediate node of a reliable transport protocol for ad hoc network (ATP) [K. Sundaresan, V. Anantharaman, H.-Y. Hsieh & R. Sivakumar, ATP: A reliable transport Protocol for ad hoc networks, IEEE Transactions on Mobile Computing, 4(6), 2005, 588–603]. In this regard, investigation is done to find out the problems experienced by the ATP flow due to the maintenance of Qt (queuing delay) and Tt (transmission delay) on per node basis. To overcome the drawback of the identified problem, a new approach which maintains Qt and Tt on per flow basis called per flow rate–based transport protocol (PFRTP ) is suggested. In PFRTP, research is done to maintain state on per flow basis rather than on per node basis. Using ns 2 simulator, the performance of PFRTP and ATP is compared. It is shown that considerable performance improvement is obtained in terms of fairness ratio.

Distributed Opportunistic Scheduling for Ad Hoc Networks With Random Access: An Optimal Stopping Approach

In this paper, we study distributed opportunistic scheduling (DOS) in an ad hoc network, where many links contend for the same channel using random access. In such a network, DOS involves a process of joint channel probing and distributed scheduling. Due to channel fading, the link condition corresponding to a successful channel probing could be either good or poor. In the latter case, further channel probing, although at the cost of additional delay, may lead to better channel conditions and hence yield higher throughput. The desired tradeoff boils down to judiciously choosing the optimal stopping rule for channel probing and distributed scheduling. In this paper, we pursue a rigorous characterization of the optimal strategies from two perspectives, namely, a network-centric perspective and a user-centric perspective. We first consider DOS from a network-centric point of view, where links cooperate to maximize the overall network throughput. Using optimal stopping theory, we show that the optimal scheme for DOS turns out to be a <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pure</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">threshold</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">policy</i> , where the rate threshold can be obtained by solving a fixed-point equation. We further devise iterative algorithms for computing the threshold. We also generalize the studies to take into account fairness requirements. Next, we explore DOS from a user-centric perspective, where each link seeks to maximize its own throughput. We treat the problem of threshold selection across different links as a noncooperative game. We explore the existence and uniqueness of the Nash equilibrium, and show that the Nash equilibrium can be approached by the best response strategy. Since the best response strategy requires message passing from neighboring nodes, we then develop an online stochastic iterative algorithm based on local observations only, and establish its convergence to the Nash equilibrium. Because there is an efficiency loss at the Nash equilibrium, we then study pricing-based mechanisms to mitigate the loss. Our results reveal that rich physical layer/MAC layer (PHY/MAC) diversities are available for exploitation in ad hoc networks. We believe that these initial steps open a new avenue for channel-aware distributed scheduling.

Computational Time-Division and Code-Division Channel Access Scheduling in Ad Hoc Networks

Using two-hop neighborhood information, we present the hybrid activation multiple access (HAMA) protocol for time-division channel access scheduling in ad hoc networks with omni-directional antennas. Different from other approaches, HAMA is a node-activation channel access protocol that also maximizes the chance of link activations using time- and code-division schemes. The throughput and delay characteristics of HAMA in randomly-generated multihop wireless networks are studied by analyses and simulations. The results of the analyses show that HAMA achieves higher channel utilization in ad hoc networks than previous similar works, namely, the node activation multiple access (NAMA), the link activation multiple access (LAMA) and pair-wise link activation multiple access (PAMA). In addition, HAMA achieves better throughout than an existing scheduling algorithm based on complete topology information, and much higher throughout than the ideal CSMA and CSMA/CA protocols. The main contribution of this work is to computationally derive channel access schedules according to local network topology information instead of on-demand negotiations or static global coordinations.