Channel Access In IEEE Research Articles

Study of an Adaptive Waiting Control Algorithm for Channel Access in IEEE 8012.11be Networks

Study of an Adaptive Waiting Control Algorithm for Channel Access in IEEE 8012.11be Networks

Multi-Link Operation with Enhanced Synchronous Channel Access in IEEE 802.11be Wireless LANs: Coexistence Issue and Solutions.

Multi-link operation is a new feature of IEEE 802.11be Extremely High Throughput (EHT) that enables the utilization of multiple links using individual frequency channels to transmit and receive between EHT devices. This paper aims to illustrate enhanced multi-link channel access schemes, identify the associated coexistence challenge, and propose solutions. First, we describe the multi-link operation of IEEE 802.11be and how the asynchronous and synchronous channel access schemes facilitate multi-link utilization. Next, we describe the design variants of the synchronous channel access scheme and demonstrate the associated coexistence challenge. Subsequently, we propose four features to address this challenge by assigning penalties to multi-link devices (repicking a backoff count, doubling the contention window size, switching to another contention window set, and compensating the backoff count) as well as five coexistence solutions derived from combinations of these features. Comparative simulation results are provided and analyzed for dense single-spot and indoor random deployment scenarios, demonstrating that the throughput and latency gains of multi-link operation differ between schemes. At the same time, we investigate the coexistence performance of multi-link operation with and without the capability of simultaneous transmission and reception and demonstrate that the proposed solutions mitigate the coexistence problem. In particular, compensating the backoff count achieves the highest coexistence performance among the proposed solutions, with a marginal throughput decrease of multi-link devices. A metric for evaluating both the throughput and latency gains and the coexistence performance of a multi-link channel access scheme using a single value is also proposed.

Performance analysis of randomized arbitration interframe space tuning algorithm for enhanced distributed channel access in IEEE 802.11p based vehicular network

AbstractThe Internet of Vehicle (IoV) aims to provide efficient vehicular communication by enhancing connectivity and user safety. IEEE 802.11p, a medium access control protocol, plays a vital role in the IoV protocol stack, which uses the enhanced distributed channel access (EDCA) method for channel contention. To deal with safety and nonsafety vehicular applications, EDCA adopts four access categories (AC), and each AC manages the channel access based on the priority of packets along with the contention window size and arbitration interframe spacing number (AIFSN). However, these contention parameters are fixed for each AC, and it does not account the real‐time network traffic. Hence, the fine‐tuning of AIFSN values and maintaining strict priority are challenging tasks for the highly dynamic vehicular network. To address these issues, this article proposes a novel probabilistic approach, namely, the randomized AIFSN tuning (RAT) algorithm for EDCA. It updates AIFSN value for every retransmission based on the vehicle density and contention intensity by preserving the strict priority behavior of the AC queues. A three‐dimensional Markov model is developed to analyze the proposed algorithm in terms of collision probability and throughput. The proposed RAT algorithm is simulated using the NS3 network simulator along with simulations for urban mobility (SUMO) for the real‐time traffic, and results are compared with other related algorithms in terms of packet loss, goodput, packet delivery ratio, and delay of each AC queue. These results reveal that the proposed RAT algorithm outperforms related algorithms under varying vehicle density.

Adaptive ternary timing covert channel inIEEE802.11

Covert channel is one of the most interesting topics in the computer networks security. Covert channel designers are seeking to discover weaknesses in the communications algorithms to use them as the medium for covert transmission. Broadcast nature of wireless channels has provided a favorable environment for the design of the hidden channels. CSMA/CA is used to control channel access in IEEE 802.11 network. Random features of this algorithm can be used to create timing covert channel. The statistical distribution of the free time intervals' duration is used in this paper for covert channel establishment. Hidden messages are sent via manipulating the timing of the overt packets' transmission. Hidden transceiver senses the wireless channel continuously to be adapted to the dynamic network condition and to be less detectable. To increase the covert channel's accuracy, some free interval durations are not used that leads to security degradation. This problem is also covered by a gap covering method that is based on the summation of the channel sensed free time interval distribution and a normal one. Hidden nodes also estimate the number of active nodes and adapt their behavior accordingly to keep their compatibility with the network. The statistical Kolmogorov-Smirnov and regularity tests are used to assess the security of the covert channel. Simulation results show that the proposed covert channel have a high bit rate along with high security. © 2016 The Authors Security and Communication Networks published by John Wiley & Sons Ltd

Differentiated service provisioning in the MAC layer of cognitive radio mesh networks

MAC protocols utilising the enhanced distributed channel access in IEEE 802.11-2007 can provide differentiated QoS in wireless networks. However, the performance of high priority traffic can be seriously degraded in the presence of strong noise over the wireless channels. Schemes utilising adaptive modulation and coding technique have also been proposed for QoS provisioning. They can provide limited protection in the presence of noise but are ineffective in a high noise scenario. Although multiple non-overlapped channels exist in the 2.4 GHz and 5 GHz spectrum, most IEEE 802.11-based multi-hop ad hoc networks today use only a single channel at anytime and cannot fully exploit the aggregate bandwidth available in the radio spectrum. By identifying vacant channels through the use of cognitive radios technique, the noise problem can be mitigated by distributing network traffic across multiple vacant channels to reduce the node density per transmission channel. In this paper, we propose the MAC-layer QoS provisioning protocol which combines adaptive modulation and coding with dynamic spectrum access. Simulation results demonstrate that MQPP can achieve better performance in terms of lower delay and higher throughput.

Spatial-Temporal relation-based Energy-Efficient Reliable routing protocol in wireless sensor networks

Delivering sensory data to the sink reliably in Wireless Sensor Networks (WSNs) calls for a scalable, energy-efficient and error-resilient routing solution. In this paper, a Spatial-Temporal relation-based Energy-Efficient Reliable (STEER) routing protocol is proposed to achieve the above goals. As opposed to the next-hop-selection-first, data-relay-next approach, which is typical in traditional routing protocols in WSNs, STEER reverses these two steps. In STEER, each data packet is relayed by broadcasting, and, among the neighbours (closer to the sink) that receive the data, one next-hop node will be elected. In so doing, eligibility as a next hop is evaluated by temporal gradient, which is similar to backoff for channel access in IEEE 802.11 systems. The value of temporal gradient is determined locally by the spatial information of each neighbour. To quantify the temporal gradient systematically, a spatial-temporal mapping function is proposed. Comprehensive simulations show that STEER performs well to provide efficient and robust routing in highly unreliable WSNs.