A CSMA Mechanism with Variable Collision Control and Priority Provision in Multichannel Mobile Ad Hoc Networks

Toward making the conventional carrier sense multiple access (CSMA) protocol transmit and control mobile ad hoc network systems, as well as reducing energy consumption, an adaptive multichannel multipriority two-dimensional probability detection and 1-stick joint control strategy carrier sense multiple access with variable collision duration and three-way handshake mechanisms (iCSMA for short) is proposed. Based on the conventional two-slot model of the CSMA protocol, iCSMA introduces a concept of collision duration (b), which divides the system’s timeslot into the duration of successful packet transmission (1 + a), the duration of collision (b + a), and the duration of the idle state (a) of the system. By employing iCSMA, the loss of the system could be reduced with a fine-tuned collision duration (b), which leads to improved performance compared to the conventional 1P-persistent CSMA protocol. Furthermore, a three-way handshake mechanism is introduced for monitoring the entire network system at a minimal cost of throughput. Toward a higher channel utilization rate, a multichannel and multipriority function is employed in the implementation of multiservice communication for the system. Besides, with an adaptive mechanism, the transmission probabilities p 1 and p 2 are reasonably set so that the system will not produce a complete collision under the condition of high load, and the throughput can also be stabilized. Based on the battery model, the lifetime of the system nodes (T) is extended. Both theoretical analysis and experimental results confirm the accuracy of the theoretical derivation.

Stochastic Network Calculus Model for Delay Distribution of Time Division Multiple Access and Carrier Sense Multiple Access in Underwater Acoustic Wireless Communication

Underwater Acoustic wireless communication becomes a popular research area for transmitting and receiving data between the communicators in the ocean environment. High accuracy in data communication can be succeeded by proficient modeling of carrier sense multiple access and time division access. For such innovations, the system has to proceed with an appropriate framework to make constant data traffic and limitations on start to finish data traffic delays. There are two major wireless communication multiple access methods that can be utilized in real-time underwater networks. One of the multiple access schemes is TDMA and another one is CSMA/CA. This paper concentrated on the modeling of TDMA and CSMA/CA also proposes the comparison of delay (end-end) of both multiple access protocols. The results using SNC to obtain delay bounds and are associated with simulation. The results show TDMA has a lesser efficiency than CSMA/CA in the acoustic environment.

Sparse Backbone and Optimal Distributed SINR Algorithms

We develop randomized distributed algorithms for many of the most fundamental communication problems in wireless networks under the Signal to Interference and Noise Ratio (SINR) model of communication, including (multi-message) broadcast, local broadcast, coloring, Maximal Independent Set, and aggregation. The complexity of our algorithms is optimal up to polylogarithmic preprocessing time. It shows—contrary to expectation—that the plain vanilla SINR model is just as powerful and fast (modulo the preprocessing) as various extensions studied, including power control, carrier sense, collision detection, free acknowledgements, and geolocation knowledge. Central to these results is an efficient construction of a constant-density backbone structure over the network, which is of independent interest. This is achieved using an indirect sensing technique, where message non-reception is used to deduce information about relative node-distances.

IEEE 802.11 based Medium Access Design for Wireless IoT-Blockchain Networks

Communication is a very basic essence of the blockchain network and must be carefully planned while integrating with IoT, where an extremely large number of devices are interconnected. In this work, blockchain nodes are assumed to use wireless channels to communicate among themselves and other elements of the IoT setup. These communications can be in unicast and broadcast manner where transmission latency and throughput are significant metrics that might jeopardize the overall system. This work is proposing a Medium Access Control (MAC) mechanism addressing these performance metrics and best suitable for wireless IoT-Blockchain system. The proposed MAC protocol is based on the widely used IEEE 802.11 protocol, Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) basic access.

CSNOMA: Carrier Sense Non-Orthogonal Multiple Access

In this paper, we investigate the possibility of the cross-layer design of a distributed random access scheme with considering physical (PHY) and multiple access control (MAC) layers, which utilizes the interference cancellation technique. In this regard, we propose a new multiple access protocol, named carrier sense non-orthogonal multiple access (CSNOMA). We consider the spatially randomly distributed interferers to realistically capture the effect of interference. The proposed protocol shows better area spectral efficiency than carrier sense multiple access (CSMA), as the node density increases. We also present a practical signaling design compatible with IEEE 802.11 DCF mode.

A LoRa-Based Linear Sensor Network for Location Data in Underground Mining

In this paper, we describe a LoRa (from “Long Range”)-based, linear sensor network we have developed for transmitting location information of personnel and equipment in an underground mine. The system is intended to be used during emergencies when existing communications infrastructure has failed. Linear networks comprise a sequence of relays that forward data to a common destination, the headend. Relays forward location information transmitted from tags carried by personnel or equipment. Relays will usually be put in place as investigators or rescuers enter the mine. LoRa is used both by the tags to communicate to the relays and by the relays to forward messages to the headend. We have implemented and tested this system, and have carried out simulations and analyses to determine its scalability, reliability and fairness. The need for robustness and reliability has led us to use flooding rather than unicast communication. We also use message sequence numbers and time-to-live fields to prevent broadcast storms. Contention is managed using a simplified Carrier Sense Multiple Access (CSMA) scheme. We also address fairness. When the network is under load messages may be dropped by relays making messages generated more hops from the headend more likely to be dropped than messages nearer the headend. We explore the relationship between unfairness, traffic load and number of relays. We also observe that a network of larger numbers of lightly loaded relays performs more effectively than smaller numbers of heavily loaded relays.