Classical Medium Access Control Research Articles

Investigating delay of the media access control protocols for IoT‐RoF using quantum entanglement

AbstractOne of the significant challenges of the Radio over fibre (RoF) Medium Access Control (MAC) protocol is the propagation delay. This delay can lead to serious issues, such as higher propagation delay resulting in collisions and unnecessary retransmissions. Quantum entanglement is an excellent candidate to overcome the propagation delay of the RoF MAC protocol. A new quantum MAC protocol is proposed, named the Quantum Entanglement‐based MAC protocol (QE‐MAC), in which Quantum Teleportation is utilised to address the propagation delay. Four entanglement states are employed to represent the control packets of the classical MAC protocol, and data is transmitted over the classical channel. Instead of using control packets such as acknowledgement, request to send, and Clear to send, state transitions are employed. This approach avoids the delay and collision issues associated with control packets, resulting in a significant improvement in network performance. The delay, duty cycle (DC), and power consumption of the proposed QE‐MAC protocol are formulated and derived. The protocol is evaluated in terms of delay, DC, and power consumption, demonstrating superior performance compared to the classical RoF MAC protocol. In comparison to published works, our proposed approach has successfully reduced both delay and power consumption by 35%.

Toward Semantic Communication Protocols: A Probabilistic Logic Perspective

Classical medium access control (MAC) protocols are interpretable, yet their task-agnostic control signaling messages (CMs) are ill-suited for emerging mission-critical applications. By contrast, neural network (NN) based protocol models (NPMs) learn to generate task-specific CMs, but their rationale and impact lack interpretability. To fill this void, in this article we propose, for the first time, a semantic protocol model (SPM) constructed by transforming an NPM into an interpretable symbolic graph written in the probabilistic logic programming language (ProbLog). This transformation is viable by extracting and merging common CMs and their connections, while treating the NPM as a CM generator. By extensive simulations, we corroborate that the SPM tightly approximates its original NPM while occupying only 0.02% memory. By leveraging its interpretability and memory-efficiency, we demonstrate several SPM-enabled applications such as SPM reconfiguration for collision-avoidance, as well as comparing different SPMs via semantic entropy calculation and storing multiple SPMs to cope with non-stationary environments.

Huffman Coding and Multi-Generation Mixing Assisted Network Coding Based MAC for QoS-Centric Secure Data Communication over MANETs

The exponential rise in wireless transmission has gained widespread attention to meet major mobile communication purposes including, Internet of Things (IoT) and Machine-to-Machine (M2M) communications. Mobile Ad-hoc Network (MANET) has emerged as one of the most viable solution to meet aforesaid mobile communication purposes; however, being decentralized and infrastructure-less network it undergoes adversaries including dynamic topology and security breaches due to malicious node attachment during routing. On the contrary, data security and allied Quality-of-Service (QoS) provision are inevitable in NextGen communication systems. Unlike routing-based security measures, Medium Access Control (MAC) based approaches are found more effective for MANETs. However, most of the classical MAC designs either address QoS or security as standalone objective. Unlike existing MAC solutions, in this paper a state-of-art novel Huffman Coding and Multi-Generation Mixing (MGM) assisted random linear network model-based MAC design (HM2-MAC) is proposed for MANET. Realizing the robustness of the network coding algorithms towards reliable, secure and error-free multicast transmission, we designed HM2-MAC in such manner that Huffman coding helps securing the source data packets, while MGM concept enables reduction in redundant packets to make overall communication resource efficient and secure. Unlike redundant packet-per-generation, MGM concept helps in reducing redundant transmission and hence achieves resource efficiency. Since, in HM2-MAC model the coefficient matrix used to encode the data is known only to the sink, no intermediate node can decode it or can pollute it. It makes multicast transmission more secure over MANET. Additionally, the use of iterative buffer flush technique preserves resources or buffer to accommodate more data for transmission and hence higher throughput. Noticeably, error sensitive packetization and MGM control strengthens our proposed model to retain optimal performance. HM2-MAC has been applied as a sub-layer of native IEEE 802.11 MAC and hence retains backward compatibility towards real-world implementation. MATLAB based simulation revealed that our proposed HM2-MAC protocol achieved almost 99.6% throughput even under varying link-loss patterns, which reveals its robustness to ensure QoS delivery with secure data transmission in MANET.

TDA-MAC: TDMA Without Clock Synchronization in Underwater Acoustic Networks

This paper investigates the application of underwater acoustic sensor networks for large scale monitoring of the ocean environment. The low propagation speed of acoustic signals presents a fundamental challenge in coordinating the access to the shared communication medium in such networks. In this paper, we propose two medium access control (MAC) protocols, namely, Transmit Delay Allocation MAC (TDA-MAC) and Accelerated TDA-MAC, that are capable of providing time division multiple access (TDMA) to sensor nodes without the need for centralized clock synchronization. A comprehensive simulation study of a network deployed on the sea bed shows that the proposed protocols are capable of closely matching the throughput and packet delay performance of ideal synchronized TDMA. The TDA-MAC protocols also significantly outperform T-Lohi, a classical contention-based MAC protocol for underwater acoustic networks, in terms of network throughput and, in many cases, end-to-end packet delay. Furthermore, the assumption of no clock synchronization among different devices in the network is a major advantage of TDA-MAC over other TDMA-based MAC protocols in the literature. Therefore, it is a feasible networking solution for real-world underwater sensor network deployments.

Survey on cooperative medium access control protocols

In the past decade, there has been ever-increasing research attention to user cooperation in the wireless communication networks. The unique challenges of wireless networks such as channel fading and variation can be addressed well by taking advantage of relaying among cooperating mobile terminals. There are many studies on cooperative communications at the physical layer to exploit spatial diversity for improving channel capacity. In recent years, user cooperation from the perspective of the medium access control (MAC) layer becomes a promising new research area. In this study, the authors present a comprehensive survey on the mainstream cooperative MAC protocols in the literature. Focusing on the contention-based solutions, the authors classify the well-known proposals according to how they address two fundamental questions for user cooperation, that is, when to cooperation and whom to cooperate with. In addition to analysing the essential features of classic cooperative MAC protocols, the authors also discuss the major research challenges and project future research directions for MAC-layer cooperation.

Layered Design of Hierarchical Exclusive Codebook and Its Capacity Regions for HDF Strategy in Parametric Wireless 2-WRC

This paper addresses a hierarchical decode-and-forward (HDF) strategy in the wireless two-way relay channel (2-WRC). This strategy uses a Hierarchical eXclusive Code (HXC) that allows full decoding of the hierarchical symbols at the relay. The HXC represents two data sources only through the exclusive law and requires side information on the complementary data at the destination (which naturally holds for the 2-WRC). The HDF strategy has the advantage over classical medium-access control (MAC) stage relaying with joint decoding in that its rate region extends beyond the classical MAC region. We present a layered design of the HXC codebook, which uses an arbitrary outer state-of-the-art capacity-approaching code [e.g., low density parity check (LDPC)] and an inner layer with an exclusive symbol alphabet. We provide basic theorems, showing that this scheme forms an HXC, and we also evaluate its alphabet-constrained rate regions. The rate regions depend on the relative channel phase parameters. Some channel rotation leads to catastrophic violation of the exclusive law. However, these values appear only in a limited range of phases and have only a mild impact on the mean capacity for some component symbol constellations.

Polling scheme for indoor LOS optical wireless LAN

A novel polling scheme, which uses beam blockage sensing and channel reassignment, is proposed. Compared to other classic medium access control (MAC) protocols, it has significant performance improvement in both system throughput and average transfer delay.