Multi-hop Broadcast Communication Research Articles

Analysis and Optimization of Multihop Broadcast Communication in the Internet of Vehicles Based on C-V2X Mode 4

Cellular Vehicle-to-Everything (C-V2X) Mode 4, developed by 3GPP, supports vehicle-to-vehicle communication without a cellular base station via LTE sidelink. The messages transmitted in the Internet of Vehicles (IoV) include periodic single-hop broadcast Beacon messages and multi-hop broadcast Emergency messages triggered by events. In this paper, we analyze the impact of multi-hop broadcast of Emergency messages in C-V2X Mode 4 on the performance of Beacon messages and propose collision probability models for Beacon messages and Emergency messages. The non-periodicity nature and lower broadcast latency requirement of the multi-hop Emergency messages may cause resource allocation conflicts in the resource selection process of C-V2X Mode 4, thus result in forwarding collision of Emergency messages and collision of subsequent Beacon messages. Therefore, we propose several multi-hop broadcast schemes for Emergency messages to reduce the collision probability by assigning independent resource grants for Emergency messages and adjusting the number of forwarding nodes. The performance of Beacon messages and Emergency messages of several different forwarding schemes proposed are simulated. The simulation results show that the proposed broadcasting schemes significantly improve the performance of Beacon messages and Emergency messages.

Volunteers Dilemma Game Inspired Broadcast Scheme for Vehicular Ad Hoc Networks

Multi-hop broadcast communication is one of the main schemes for supporting message dissemination in vehicular ad hoc networks. In this paper, we propose an efficient receiver-oriented broadcast scheme in which the receiving vehicles' probability of forwarding is modeled by the symmetric volunteer's dilemma game. Based on this game, the vehicles that receive the broadcast message are players. At least one of the players should pay a cost and be a volunteer to rebroadcast the message, and then all will benefit from this volunteering. Utilizing fuzzy logic techniques and considering information from the network layer about local density and probability of transmission, the contention window size at the MAC layer will be adjusted. We develop ns-3 simulations to evaluate the performance of the proposed volunteer's dilemma inspired broadcast (VDIB) scheme in terms of reachability, number of rebroadcasts per covered vehicle, number of bytes sent per covered vehicle, and per-hop delay. VDIB performance is compared with that of the distance-to-mean broadcast method, broadcast component of contention-based forwarding, distribution-adaptive distance with channel quality, statistical location assisted broadcast, fuzzy logic-based broadcast, bandwidth efficient fuzzy logic assisted broadcast, and intelligent hybrid adaptive broadcast protocols in both highway and urban environments.

Integrating Licensed and Unlicensed Spectrum in the Internet of Vehicles with Mobile Edge Computing

In order to satisfy the application requirements in Internet of Vehicles scenarios, it is important to efficiently utilize different wireless spectrums while considering the dynamic features of network environments. In this article, we propose a context-aware communication approach to efficiently integrate different licensed and unlicensed spectrums leveraging the edge computing technologies. In addition, a joint aggregation, caching, and decentralization scheme is proposed to efficiently combine route aggregation, data caching, and decentralized computing approaches to compensate for the limited wireless resources. Asynchronous multihop broadcast and asynchronous multihop unicast schemes are introduced to improve the routing performance in multihop broadcast and multihop unicast communications, respectively. We conduct computer simulations to evaluate the effects of the proposed scheme by comparing it with other baseline approaches.

SDN-enabled hybrid emergency message transmission architecture in internet-of-vehicles

ABSTRACTWith the increasing number of vehicles connected to the Internet-of-Things (IoT), Internet-of-Vehicles (IoV) is becoming a hot research topic. It can improve traffic safety and efficiency and promote the development of the intelligent transportation that is a very important element in Smart Cities. As an important part of the safety application in IoV, the emergency message transmission is designed to inform all the vehicles in the relevant area timely of the accident information through the multi-hop broadcast communication. In this paper, we propose a hybrid emergency message transmission (HEMT), which introduces the SDN technology into the vehicular network environment and utilizes the flexibility of inter-vehicle communication. By deploying SDN-enabled central controller and RSU switches, we can obtain reliable and fast emergency message dissemination. Moreover, considering the space between the coverages of RSUs caused by the sparse deployment, we also use inter-vehicle multi-hop broadcast communication to improve the message coverage ratio by adding the packet modification module on the RSU switch. Simulation results show the feasibility and effectiveness of our proposed scheme.

DiSIF: A Distance-Based Silencing Technique for Multi-Hop Broadcast Communications in Pedestrian Ad-Hoc Networks

In this paper, we focus on a particular type of opportunistic ad-hoc networks, namely Pedestrian Ad-hoc NETworks (PANETs). In PANETs, nodes are densely distributed and each node may transmit information to all other nodes in the network via multi-hop broadcasting. Even though flooding is the simplest technique to broadcast information with multi-hop communications, it can be very inefficient because of redundant transmissions which may induce collisions. This problem is known, in the literature, as the “broadcast storm problem.” In this work, we present a novel probabilistic forwarding technique, denoted as Distance-based Silencing IF (DiSIF), which is derived from the probabilistic broadcasting protocol Irresponsible Forwarding (IF) and one of its extensions, denotes Silencing IF (SIF). The performance of the DiSIF protocol is analyzed and compared with those of other existing protocols, investigating the impact of fundamental network parameters. Lower bounds (exact and approximate) on the average number of hops, expedient to evaluate the propagation efficiency of DiSIF, are also derived. Finally, under the assumption that each node (e.g., a smartphone) relies on Global Positioning System (GPS) to estimate its position, the robustness of DiSIF against a GPS positioning error is investigated.

Performance modeling and analysis of emergency message propagation in vehicular ad hoc networks

ABSTRACTReliability and timeliness are two critical requirements of vehicle safety‐related communication services in VANETs. In this paper, we develop an analytical model to analyze the packet reception rate and end‐to‐end delay of emergency message delivery operation in a VANET environment when multihop broadcast communications are used. The model is applied to derive closed‐form expressions of the end‐to‐end delay of two popular multihop message propagation methods, that is, the farthest‐distance method and the counter‐based method. Extensive simulations are conducted to validate the correctness of the theoretic results and compare the performance of the two message propagation methods. Observations are provided for the design of efficient and robust emergency message propagation methods for vehicular wireless communication networks. Copyright © 2012 John Wiley & Sons, Ltd.

Simulation studies of the behavior of multihop broadcast networks

The performance (throughput and delay) of the multihop broadcast communication networks is studied via a simulation model that includes channel access, transmission scheduling, buffer, management, and hop-by-hop acknowledgment protocols. The parameters considered are the data and acknowledgment packets transmission probabilities, timeout periods, and buffer sizes. The performance of echo acknowledgment, all-active acknowledgment, and a mixed acknowledgment scheme based on nodes connectivities are also studied. Systems parameters that yield best performance for each configuration are given. Our studies reveal that the string configuration yielded better throughput than the star configuration; further, echo acknowledgment yield better performance than active acknowledgment in a string multihop broadcast network.