Slotted MAC Protocol Research Articles

Performance Evaluation of Enhanced Slotted AlohaCA Protocol on Planet Mars

The launch and successful operation of the Mars Cube One (MarCO) CubeSat in May 2018 heralded a new era in solar system exploration and the setup of the first Interplanetary CubeSat Network (ICN). The success of this mission could give rise of an Interplanetary DTN–Based CubeSat network, in which the CubeSat Nanosatellite, as DTN custody node, plays the role of Data Mule to collect data from rovers on a planet such as Mars. In order to maximize the contact volume which is the amount of transmitting data from rovers to the CubeSat during its pass over their service zone, we will need to design an efficient MAC protocol. This research focuses on the simulation and evaluation of the performance of the Slotted AlohaCA MAC Protocol on the planet Mars compared to Earth taking into account the different properties between the two planets, such as radius, mass and speed of rotation of the Nanosatellite in its orbital at the same altitude. We have conducted many simulations using the NS2 simulator that takes into consideration the spatial dynamic behavior of the Nanosatellite, which is dependent on motion of the Nanosatellite in its orbit. Three appropriate performance measures are evaluated: Throughput, stability and power consumption. The obtained simulation results on the planet Mars show an improvement on performance of the Slotted AlohaCA on the planet Mars compared to Earth.

SMLMAC-HEAP: Slotted Multi-Layer MAC Protocol for Wireless Sensor Networks Powered by Ambient Energy Harvesting

Objectives: To study the lifetime of Wireless Sensor Network (WSN) as well as to propose and simulate a suitable approach so that the Quality-of-Service (QoS) of the network in terms of throughput improved when compared with the previous methods. Methods: The lifetime of WSN depends on the MAC layer because energy consumption is more due to the sharing access of media. Our approach is designed not only to adopt the division of the MAC layer into a number of slots by keeping both listen and sleep mode but also using the solar harvested energy; hence, the network’s lifetime is improved with the compared protocol. Our approach with compared protocol is simulated through MATLAB simulator on EZ430-RF2500-SHE” (Datasheet of Texas Instruments’). Findings: In WSN, we found that energy consumption is more at the MAC layer, so network performance degrades in terms of lifetime. To solve the issue of energy consumption in WSN, researchers focused on and designed several techniques to improve the MAC layer. To bring out the practicality of the proposed protocol, we present a case study on the variation of layers with slots in terms of throughput metrics. Finally, the simulation result shows that the proposed protocol performs better than MLMAC-HEAP, Probabilistic Polling and Optimal Polling from layer 7 with slot 7. Novelty: The proposed approach merges the two concepts; one is by using the ambient solar energy, and the other, by adopting slot concepts for each layer of MAC. Keywords: MAC; MLMAC; MLMAC-HEAP; WSN

A Slotted Multichannel MAC Protocol for Fair Resource Allocation in VANET

This article proposes a slotted multichannel medium access control (SMMAC) protocol for VANETs to reduce CCH congestion, decrease RSU dependency, increase safety and data packet's reliability and improve fairness among vehicles. The main entity is the cluster head that not only notifies all the vehicles under the same cluster about the present state of service channel and future data transmissions but also imposes a condition on the maximum number of vehicles allowed inside a cluster. Controlled vehicle density reduces CCH collisions and as a result, it makes the protocol better in terms of packet delivery. To eliminate the inter-cluster hidden terminal problem, in the proposed algorithm, each cluster uses a service channel different from its neighboring cluster. Analyzing the system for both dense and sparse scenario it can be seen through simulation results that the proposed protocol performs much better in comparison to IEEE 802.11p with respect to Throughput, PDR and Delay.

Exploiting Data-Dependent Transmission Control and MAC Timing Information for Distributed Detection in Sensor Networks

In this paper, we propose a data-dependent transmission control policy over the slotted ALOHA MAC protocol and a cross-layered fusion rule that exploits MAC timing information for distributed detection in sensor networks. In this system, each sensor first makes a local decision at the beginning of each observation period and transmits the decision to the fusion center over a random access channel. Based on the slotted ALOHA random access protocol, we propose a class of data-dependent transmission control policies that assign to sensors their transmission probabilities according to the reliability of their local decisions. For the case with i.i.d. observations in each time slot, we show that the optimal transmission control function takes on the form of a thresholding function. That is, a sensor will transmit in a given time slot if and only if its local log-likelihood ratio exceeds a certain threshold. When observations are made only every several time slots, the message arrival time at the fusion center, which is spread over the observation period of duration K > 1, will embed the reliability of the received sensors' decisions as a result of the data-dependent transmission control. This timing information can be accounted for in the fusion rule to further enhance performance. Finally, we extend the proposed strategies to multicluster sensor network scenarios, where the sensors' local decisions are transmitted to the fusion center in a two-hop fashion. We show, through numerical simulations, that the proposed schemes outperform both conventional slotted ALOHA and TDMA-based schemes that do not adopt cross-layered transmission and fusion strategies.

A slotted access control protocol for metropolitan WDM ring networks

In this study we focus on the serious scalability problems that many access protocols for WDM ring networks introduce due to the use of a dedicated wavelength per access node for either transmission or reception. We propose an efficient slotted MAC protocol suitable for WDM ring metropolitan area networks. The proposed network architecture employs a separate wavelength for control information exchange prior to the data packet transmission. Each access node is equipped with a pair of tunable transceivers for data communication and a pair of fixed tuned transceivers for control information exchange. Also, each access node includes a set of fixed delay lines for synchronization reasons; to keep the data packets, while the control information is processed. An efficient access algorithm is applied to avoid both the data wavelengths and the receiver collisions. In our protocol, each access node is capable of transmitting and receiving over any of the data wavelengths, facing the scalability issues. Two different slot reuse schemes are assumed: the source and the destination stripping schemes. For both schemes, performance measures evaluation is provided via an analytic model. The analytical results are validated by a discrete event simulation model that uses Poisson traffic sources. Simulation results show that the proposed protocol manages efficient bandwidth utilization, especially under high load. Also, comparative simulation results prove that our protocol achieves significant performance improvement as compared with other WDMA protocols which restrict transmission over a dedicated data wavelength. Finally, performance measures evaluation is explored for diverse numbers of buffer size, access nodes and data wavelengths.

Throughput Analysis of Fading Sensor Networks with Regular and Random Topologies

We present closed-form expressions of the average link throughput for sensor networks with a slotted ALOHA MAC protocol in Rayleigh fading channels. We compare networks with three regular topologies in terms of throughput, transmit efficiency, and transport capacity. In particular, for square lattice networks, we present a sensitivity analysis of the maximum throughput and the optimum transmit probability with respect to the signal-to-interference ratio threshold. For random networks with nodes distributed according to a two-dimensional Poisson point process, the average throughput is analytically characterized and numerically evaluated. It turns out that although regular networks have an only slightly higher average link throughput than random networks for the same link distance, regular topologies have a significant benefit when the end-to-end throughput in multihop connections is considered.

Opportunistic routing in multi-hop wireless networks

This paper describes Extremely Opportunistic Routing (ExOR), a new unicast routing technique for multi-hop wireless networks. ExOR forwards each packet through a sequence of nodes, deferring the choice of each node in the sequence until after the previous node has transmitted the packet on its radio. ExOR then determines which node, of all the nodes that successfully received that transmission, is the node closest to the destination. That closest node transmits the packet. The result is that each hop moves the packet farther (or average) than the hops of the best possible pre-determined route.The ExOR design addresses the challenge of choosing a forwarding node after transmission using a distributed algorithm. First, when a node transmits a packet, it includes in the packet a simple schedule describing the priority order in which the potential receivers should forward the packet. The node computes the schedule based on shared measurements of inter-node delivery rates. ExOR then uses a distributed slotted MAC protocol for acknowledgements to ensure that the receivers agree who the highest priority receiver was.The efficacy of ExOR depends mainly on the rate at which the reception probability falls off with distance. Simulations based on measured radio characteristics [6] suggest that ExOR reduces the total number of transmissions by nearly a factor of two over the best possible pre-determined route.

A slotted mac protocol for efficient bandwidth utilization in wdm metropolitan access ring networks

The paper proposes an original wavelength-division multiplexing slotted-ring network architecture with nodes that use one fixed transmitter and fixed receivers. It is shown, through theoretical predictions and simulation results, how a simple slotted medium access control protocol can be implemented to achieve fairness between access nodes and efficient bandwidth utilization when used in a metropolitan access network. Performance for both source and destination stripping schemes has been analytically derived and simulated with a realistic self-similar traffic model. A modified node architecture using a tunable receiver has also been considered and the impact of receiver collisions has been evaluated and analyzed. Finally, the effect of using unbalanced traffic sources has also been analyzed and simulated.

A Slotted MAC Protocol for Variable Packet Sizes over WDM Metropolitan Access Ring Networks

Article A Slotted MAC Protocol for Variable Packet Sizes over WDM Metropolitan Access Ring Networks was published on October 1, 2003 in the journal Journal of Optical Communications (volume 24, issue 5).

Photonic packet WDM ring networks architecture and performance

This article reviews various WDM ring architectures and pays special attention to their implementation in the metropolitan environment. A number of possible network architectures as well as protocols are reviewed. The article also proposes and analyses a WDM slotted-ring network architecture with nodes that use one fixed transmitter and fixed receivers. Used as a metropolitan access network, it is shown through simulation how a simple slotted MAC protocol can be implemented in this network to achieve efficient bandwidth utilization. Throughput, delay and packet dropping probability results are presented under Poisson and self-similar traffic.

Performance evaluation of a new MAC protocol for WDM metropolitan access ring networks

AbstractThis article considers a WDM slotted‐ring network architecture. A slotted MAC protocol was designed to be used in a metropolitan environment. The results of a discrete event simulation are presented. Assuming that a maximum load threshold is not exceeded, fairness between access nodes is achieved by introducing a very simple mechanism. Excellent queuing delay and packet dropping probability results are obtained. Future developments are presented as they are expected to improve the efficiency and introduce QoS capabilities and congestion avoidance mechanisms. Copyright © 2001 John Wiley & Sons, Ltd.

All-optical WDM multi-rings with differentiated QoS

This article considers all-optical WDM networks based on a slotted multichannel ring topology, where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter; and shows how to design very effective MAC protocols that provide packet-mode transport to multiple information flows with different QoS requirements. As an example, we describe SR3, a collision-free slotted MAC protocol which combines a packet scheduling strategy (called SRR), a fairness control algorithm (called MMR); and a reservation mechanism. SRR achieves an efficient exploitation of the available bandwidth, MMR guarantees fair throughput access to each node, and SR3, by permitting slot reservations, leads to tighter control on access delays, and can thus effectively support traffic classes with different QoS requirements.