Collision-free Protocol Research Articles

FSE2R: An Improved Collision-Avoidance-based Energy Efficient Route Selection Protocol in USN

The 3D Underwater Sensor Network (USNs) has become the most optimistic medium for tracking and monitoring underwater environment. Energy and collision are two most critical factors in USNs for both sparse and dense regions. Due to harsh ocean environment, it is a challenge to design a reliable energy efficient with collision free protocol. Diversity in link qualities may cause collision and frequent communication lead to energy loss; that effects the network performance. To overcome these challenges a novel protocol Forwarder Selection Energy Efficient Routing (FSE2R) is proposed. Our proposal’s key idea is based on computation of node distance from the sink, Residual Energy (RE) of each node and Signal to Interference Noise Ratio (SINR). The node distance from sink and RE is computed for reliable forwarder node selection and SINR is used for analysis of collision. The novel proposal compares with existing protocols like H2AB, DEEP, and E2LR to achieve Quality of Service (QoS) in terms of throughput, packet delivery ratio and energy consumption. The comparative analysis shows that FSE2R gives on an average 30% less energy consumption, 24.62% better PDR and 48.31% less end-to-end delay compared to other protocols.

To Analyze Energy Aware MAC Protocols for Wireless Sensor Networks

Sensors are used in many fields to collect the information and send it to the central location;the role of energy conservation is more important in Media Access Protocol. This paper presents the limitation and description of MAC protocols with different techniques used in BMAC, LMAC, XMAC protocols and we implement BMAC, LMAC, XMAC protocol in Omnetpp5.5.1 simulator as per default configuration and values to run the protocols in omnetpp5.5.1 simulator and compare these three protocols as per energy parameters and find out the energy efficientMAC protocol. Our simulation result shows that the XMAC protocol is a more energy efficient, collision free protocol, the no of packets loss is also reduced in the XMAC protocol.

Beamforming Galvanic Coupling Signals for IoMT Implant-to-Relay Communication

Implants are poised to revolutionize personalized healthcare by monitoring and actuating physiological functions. Such implants operate under challenging constraints of the limited battery energy, heterogeneous tissue-dependent channel conditions, and human-safety regulations. To address these issues, we propose a new cross-layer protocol for galvanic coupled implants, wherein the weak electrical currents are used in place of classical radio frequency links. As the first step, we devise a method that allows multiple implants to communicate individual sensed data to each other through code division multiple access, combined with compressive sensing method to lower the transmission time and save energy, as well as delegates the computational burden of dispreading and decoding only to the on-body surface relays. Then, we devise a distributed beamforming approach that allows coordinated transmissions from the implants to the relays by considering the specific tissue path chosen and tissue heating-related safety constraints. We then proceed to implement distributed beamforming on a phantom of human tissue and prove an increase in received signal strength and a decrease in BER due to constructive interference of the signals of each implant. Our contributions are twofold: First, we devise a collision-free protocol that prevents undue interference at neighboring implants, especially for multiple deployments. Second, this is the first application of near-field distributed beamforming in human tissue. Simulation results reveal significant improvement in the network lifetime for implants of up to 79% compared to the galvanic coupled links without beamforming. In addition, the implementation of phantom tissue proves improved communication metrics when beamforming is used.

Medium access control schemes for flat mobile wireless sensor networks

One aspect of Mobile Wireless Sensor Networks (MWSNs) is the MAC protocol, which is critical in terms of reliability, delay and energy consumption. This work begins with a literature review, showing that the majority of MWSN MACs are designed for hierarchical architectures, demonstrating that there is a lack of MACs intended for flat architecture MWSNs. Subsequently, we propose three new MAC protocols, uniquely designed for flat MWSNs. Explicitly, the proposed MACs are Carrier Sense Multiple Access with Dedicated Slots, Network Division Multiple Access with Collision Avoidance and Network Division Multiple Access with Dedicated Slots, which are specifically designed to work with the state-of-the-art Location Aware Sensor Routing protocol. Extensive modelling and simulation is done in dense and sparse scenarios with varying traffic levels to evaluate the impact of the proposed from the perspective of both the link and network layers. Given the uniqueness of the proposed protocols, four well-known MACs are also included to give a performance reference to the results. The MAC results show that the collision-free protocols give the best reliability and that Global-TDMA consistently yields the highest level of throughput. This highlights the importance of taking into account both MAC and routing during the design process.

Large and Dense Swarms: Simulation of a Shortest Path Alarm Propagation

This paper deals with the transmission of alarm messages in large and dense underwater swarms of Autonomous Underwater Vehicles (AUVs) and describes the verification process of the derived algorithm results by means of two simulation tools realized by the authors. A collision-free communication protocol has been developed, tailored to a case where a single AUV needs to send a message to a specific subset of swarm members regarding a perceived danger. The protocol includes a handshaking procedure that creates a silence region before the transmission of the message obtained through specific acoustic tones out of the normal transmission frequencies or through optical signals. This region will include all members of the swarm involved in the alarm message and their neighbours, preventing collisions between them. The AUV sending messages to a target area computes a delay function on appropriate arcs and runs a Dijkstra-like algorithm obtaining a multicast tree. After an explanation of the whole building of this collision-free multicast tree, a simulation has been carried out assuming different scenarios relevant to swarm density, signal power of the modem and the geometrical configuration of the nodes.

On the distributed construction of a collision-free schedule in multi-hop packet radio networks

This paper introduces a protocol that distributively constructs a collision-free schedule for multi-hop packet radio networks in the presence of hidden terminals. As a preliminary step, each wireless station computes the schedule length after gathering information about the number of flows in its neighbourhood. Then, a combination of deterministic and random backoffs are used to reach a collision-free schedule. A deterministic backoff is used after successful transmissions and a random backoff is used otherwise. It is explained that the short acknowledgement control packets can easily result in channel time fragmentation and, to avoid this, the use of link layer delayed acknowledgements is advocated and implemented. The performance results show that a collision-free protocol easily outperforms a collision-prone protocol such as Aloha. The time that is required for the network to converge to a collision-free schedule is assessed by means of simulation.

Collision-free arbitration protocol for active RFID systems

Collisions between tags greatly reduce the identification speed in radio frequency identification (RFID) systems and increase communication overhead. In particular for an active RFID system, tags are powered by small batteries, and a large number of re-transmissions caused by collisions can deteriorate and exhaust the tag energy which may result in missing tags. An efficient collision-free arbitration protocol for active RFID systems is proposed in this paper. In this protocol, a new mechanism involving collision detection, collision avoidance, and fast tag access is introduced. Specifically, the pulse burst duration and busy-tone- detection delay are introduced between the preamble and data portion of a tag-to-reader (T-R) frame. The reader identifies tag collision by detecting pulses and transmits a busy tone to avoid unnecessary transmission when collision occurs. A polling process is then designed to quickly access the collided tags. It is shown that the use of the proposed protocol results in a system throughput of 0.612, which is an obvious improvement when compared to the framed- slotted ALOHA (FSA) arbitration protocol for ISO/IEC 18000- 7 standard. Furthermore, the proposed protocol greatly reduces communication overhead, which leads to energy conservation.

Spatio-temporal sampling rates and energy efficiency in wireless sensor networks

A multi-hop network of wireless sensors can be used to gather spatio-temporal samples of a physical phenomenon and transmit these samples to a processing center. This paper addresses an important issue in the design of such networks: determining the spatio-temporal sampling rate of the network under conditions of minimum energy usage. A new collision-free protocol for gathering sensor data is used to obtain analytical results that characterize the tradeoffs among sensor density, energy usage, throughput, delay, temporal sampling rates and spatial sampling rates in wireless sensor networks. We also show that the lower bound on the delay incurred in gathering data is O(k/sup 2/n) in a clustered network of n sensors with at most k hops between any sensor and its clusterhead (CH). Simulation results on the tradeoff between the achievable spatial sampling rates and the achievable temporal sampling rates when IEEE 802.11 distributed coordination function (DCF) is used as the media access scheme are provided and compared with the analytical results obtained in this paper.

On achieving fairness and efficiency in high-speed shared medium access

Channel access has been an active research area for the past two decades. Several protocols have been proposed in literature to efficiently utilize the channel bandwidth. Some of the recently proposed protocols achieve a near-ideal channel utilization. However, the efficiency in utilization comes at the expense of certain unfairness in delay characteristics. In this paper, a new channel-access protocol, called access mechanism for efficient sharing in broadcast medium networks (AMES-BM), is developed based on a deterministic binary tree-splitting technique to achieve efficient sharing of bandwidth. In AMES-BM, the stations are dynamically mapped to leaf nodes of a binary tree. The stations are then divided into smaller groups that mimic the behavior of an ideal transmission queue. Collisions are allowed to occur within these groups and are resolved using a variation of the conventional binary tree-splitting technique.The performance of AMES-BM is similar to that of a collisionbased protocol under low loads and to that of a collision-free protocol under high loads. Besides achieving a near-optimal channel utilization, the proposed protocol also guarantees fairness with respect to delay for messages of varying lengths. The deterministic nature of the protocol makes it more attractive for real-time applications.

A Collision-Free Reservation Protocol for WDM Optical Star Networks

WDM single-hop networks allow a pair of nodes to exchange data packets directly and require an efficient protocol that coordinates the process of data transmission. However, the network performance with such protocols can be deteriorated by collisions that occur on control channel, data channel, destination node and source node. We present a Collision-Free Reservation Protocol (CFRP) for WDM single-hop networks with a passive optical star coupler. To eliminate all causes of collision, the CFRP properly distributes the transmission schedule both in time (position of data channel on the time axis) and space (wavelength of data channel to be used). Compared with the previous reservation-based protocols, the proposed CFRP enhances the overall network performance. This improvement in terms of network throughput and delay is verified by simulation.

On two modified ethernets

The paper presents two variations of a Local Area Network based on a modified concept of Ethernet. Unlike many other concepts (e.g. collision-free protocols) the proposed modifications are simple, realistic and inexpensive. In particular, the essence of the CSMA-CD protocol is retained. The performance of the new networks is demonstrated to be superior to the performance of standard Ethernet. The second network (DCS) seems to be particularly interesting, as (despite the collision protocol) its asymptotic effective throughput turns out to be equal to the theoretical maximum. The presented networks are used to demonstrate a certain approach to investigating and eliminating the unfairness of a bus protocol in which stations can transmit spontaneously.

A lower bound on the period length of a distributed scheduler

Ad-scheduling of a graphG is a sequence of rounds, each consisting of some of the nodes of the graph, such that the distance between any two nodes participating in the same round is greater thand. Ad-scheduler is a protocol that determines ad-scheduling ofG. A 1-scheduler is applicable to process scheduling in a resource-sharing system, and to proper communication scheduling of the half-duplex model in communication networks. A 2-scheduler can be used as a collision-free protocol for radio networks.

On two collision protocols for high speed bus LANs

It is commonly believed that collision protocols are impractical for very fast bus networks, owing to the constraints on the minimum packet length. In this paper, we present two collision protocols that contradict this opinion. These protocols are two representatives of the so-called Piggyback Ethernet family. They incur no synchronisation overhead under very light load, and under heavy traffic conditions they perform no worse than collision-free protocols. Piggyback ethernets are implementable on the basis of a simple, unsegmented, bidirectional, broadcast-type medium. Thus, they can be viewed as refinements of commercial Ethernet aimed at providing high-performance service in the environments when the packet length is small in comparison to the propagation length of the bus.

A Virtual Token Protocol For Bus Networks: Correctness and Performance

AbstractWe propose a MAC-level protocol with bounded packet delay time for Ethernet-type networks. The proposed protocol, named Virtual Token, aims at improving the performance of CSMA/CD under heavy load, retaining its good characteristics for light and moderate traffic conditions. The improvement is achieved by passing an implicit token. Collision-free protocols based on passing explicit tokens are known to perform well under heavy traffic conditions, but they are outperformed by collision protocols for lighter loads. Unfortunately, the maximum packet delay in pure collision protocols is not bounded which is unacceptable in certain applications. We prove that the Virtual Token protocol guarantees packet delivery in a bounded time, and report results of numerous simulation experiments carried out to investigate its performance.

A Hybrid Multiple-Access Protocol for Data and Voice-Packet Over Local Area Networks

This correspondence presents HYMAP, a hybrid multiple access protocol for local area networks. The protocol combines features of both CSMA/CD and a collision-free protocol. Control is transferred from one protocol to the other according to state information sensed on the channel. The performance of HYMAP is evaluated by computer simulation for both data and voice packets. It compares favorably to other well-known multiple-access protocols. The number of packet-voice terminals that can be supported by HYMAP is higher than that obtained by using other protocols. Statistical analysis of the simulation results is also given.

An efficient collision-free protocol for prioritized access-control of cable or radio channels

We describe and analyze an efficient collision-free channel-access protocol for cable or radio networks with an arbitrary spatial (one-, two- or three-dimensional) fixed node configuration. The protocol is robust and provides distributed access-control under a myriad of possible priority disciplines, including Fixed, Fair Round-Robin and Prioritized Round-Robin disciplines. The protocol optimally employs available information on network topology, to provide performance characteristics (throughput and delay) that are at least as good as and in most cases much better than those of other published protocols that employ less information. The performance advantage is especially significant for networks with a large number of nodes.