Broadcast Algorithm Research Articles

A Fault-Tolerant Token-Based Atomic Broadcast Algorithm

Many atomic broadcast algorithms have been published in the last 20 years. Token-based algorithms represent a large class of these algorithms. Interestingly, all the token-based atomic broadcast algorithms rely on a group membership service and none of them uses unreliable failure detectors directly. This paper presents the first token-based atomic broadcast algorithm that uses an unreliable failure detector instead of a group membership service. It requires a system size that is quadratic in the number of supported failures. The special case of a single supported failure (f=1) requires n=3 processes. We experimentally evaluate the performance of this algorithm in local and wide area networks, in order to emphasize that atomic broadcast is efficiently implemented by combining a failure detector and a token-based mechanism. The evaluation shows that the new token-based algorithm surpasses the performance of the other algorithms in most small-system settings.

Synchronous multicast and broadcast service in multi-rate IEEE 802.16j WiMAX relay network

IEEE 802.16j Mobile Multihop Relay Standard defines multi-hop relay operation in a WiMAX system. It uses a novel synchronous multicast and broadcast transmission mechanism to achieve macro diversity. With the newly introduced synchronous delivery constraint, the multicast data delivery algorithm should be designed differently to enhance system performance. This paper provides Multi-Rate Selection Algorithm (MRSA) for multicast and broadcast (MBS) data delivery. It could reduce the data distribution delay from the BS to all the RSs. Besides, we also propose the path selection algorithm to further improve the effectiveness of MRSA. Our simulation results show that using MRSA with our shortest-path path selection algorithm, the delay for data delivery in 802.16j MBS system could be greatly reduced. The proposed scheme could achieve the performance closed to the optimal solutions. To the authors' best knowledge, this is the first research work to investigate the IEEE 802.16j multicast and broadcast problem.

Improved approximation algorithms for maximum lifetime problems in wireless networks

A wireless ad-hoc network consists of a collection of transceivers positioned in the plane. Each transceiver is equipped with a limited battery charge. The battery charge is reduced after each transmission, depending on the transmission distance. One of the major problems in wireless network design is to route network traffic efficiently, so as to maximize the network lifetime, i.e., the number of successful transmission rounds. In this paper, we consider Rooted Maximum Lifetime Broadcast/Convergecast problems in wireless settings. The instance consists of a directed graph G=(V,E) with edge-weight w(e) (the power needed to transmit a message along e) for every e∈E, node capacity b(v) (the battery charge of v) for every v∈V, and a root r. The goal is to find a maximum size collection {T1,…,Tk} of Broadcast/Convergecast trees rooted at r such that ∑i=1kw(δTi(v))≤b(v), where δT(v) is the set of edges leaving v in T. In the Single Topology version, the same tree is used to transmit all the messages, namely, all the Broadcast/Convergecast trees Ti are identical. Using recent work on degree constrained network design problems (Nutov, 2008) [26], we give constant ratio approximation algorithms for various broadcast and convergecast problems, improving the previously best known approximation Ω(⌊1/logn⌋) by Elkin et al. (2011) [12]. Similar results are shown for the more general Rooted Maximum Lifetime Mixedcast problem, where in addition we are given an integer γ≥0, and the goal is to find the maximum integer k so that k Broadcast and γk Convergecast rounds can be performed. We also consider the model with partial level aggregation.

Revisiting relative neighborhood graph-based broadcasting algorithms for multimedia ad hoc wireless networks

Multimedia broadcasting is a popular application in an ad hoc wireless network, itself composed of battery-operated nodes. Hence, energy conservation and avoidance of frequent re-construction of broadcast paths are crucial to ensure robust and uninterrupted service of multimedia broadcasting applications. This paper introduces a class of distributed broadcast algorithms based on variations of Relative Neighborhood Graphs (RNG). In contrast to the original RNG-based algorithms, the proposed algorithms consider the remaining battery energy of nodes and the distance between nodes as criteria for determining the relative neighborhood of a node. This approach is intended to boost the resiliency of the broadcast path by avoiding the choice of nodes with low remaining battery capacity as rebroadcast nodes. Extensive simulations are conducted, demonstrating that the proposed algorithms improve over the original RNG in several aspects, including the reduction of broadcast storms, longer path lifetime, and shorter broadcast latency.

Role-based Broadcasting Algorithm in Wireless Sensor Networks

In application-driven environment of wireless sensor networks, the role-based designing is a very important method to realize dynamic application, and role-packet broadcasting is a challenging problem. For large-capacity role-packet, the biggest problem is that there is too much cost in broadcasting. A role-based broadcast algorithm for wireless sensor networks (CRD algorithm) was presented, which use context information to calculate the relying cost function in order to reduce redundancy broadcast cost. On the basis of fully analyzing node's broadcast cost, the CRD algorithm optimizes the relaying cost function according to the requirements of application services and the around environment information of a node. Simulation and performance evaluations were down about broadcast rate, arrival rate, energy consumption. The results showed that the algorithm had high performance advantages in broadcasting the large-capacity role-packet.

Reliability-aware Algorithms of Multipoint Relay with Application Analysis in the Flooding Broadcast of Link-16

The multipoint relay (MPR) flooding broadcast in Link-16 is a multi-objective network programming problem with multi-constraints. Trying to obtain the fewest nodes in MPR set and the maximum reliability is seldom considered in existing flooding broadcast algorithms under the multiple QoS (Quality of Service) constraints. According to the different objectives considered preferentially, two reliability-aware heuristic algorithms of flooding broadcast RA-MPR-N and RA-MPR-R are proposed in this paper. Comparing with the paired-slot flooding relay, RA-MPR-N selects as few neighbor nodes as possible to cover all two-hop nodes, while RA-MPR-R guarantees the maximum reliability. Both theoretical analysis and simulation show that the number of nodes in MPR set obtained by RA-MPR-N and the average reliability obtained by RA-MPR-R are satisfactory.

Information dissemination in VANETs based upon a tree topology

In this work, we focus on vehicular ad hoc networks, also called VANETs, which are communication networks that devices (in this case vehicles) use to exchange messages in a decentralized fashion, i.e., using no preexisting infrastructure. We first assess the feasibility of relying on a tree-based topology management structure for mobile ad hoc networks and in particular for VANETs. Next, we enhance DAGRS, an existing decentralized model for enabling distributed tree management and build BODYF on it, an efficient broadcast algorithm. Several broadcasting algorithms of the state of the art are implemented in order to compare the performance of BODYF. The approach is validated by simulation through three realistic scenarios located in Luxembourg city: the city center for both pedestrian and vehicles, and a highway environment. The comparison is made in terms of the coverage achieved by the broadcasting process as well as the complexity of the messages. DAGRS/BODYF approach outperforms other existing protocols in terms of both the number of devices reached and the network use.

A Novel Broadcast Algorithm of Wireless Sensor Networks Based on Multiple Objective Programming and Genetic Algorithm

Considering the restriction of physical resource and the environment, we propose a new broadcast path algorithm based on genetic algorithm and ideal point model. The proposed algorithm combines multiple constrains and utilizes the advantages of genetic algorithm in multiple objective programming. Simulation results show that the proposed algorithm reveal better performance on efficiency resource utilization.

Going realistic and optimal: A distributed multi-hop broadcast algorithm for vehicular safety

A subject of great interest and important investments by governments, navigation system companies and street management authorities is highway safety. In this context, an important role is played by applications designed to warn drivers of upcoming dangers. An example is vehicular accident warning systems, which advertise accident events to approaching vehicles. The effectiveness of currently in use vehicular accident warning systems can be jeopardized by their: (a) inability to provide an accident warning to the closest approaching vehicles; and, (b) high delays in advertising an event. In fact, such systems are unable to reach the vehicles that are closest to an accident site due to the absence of any deployed automatic detection and broadcast mechanisms. The future deployment of Vehicular Ad hoc Networks (VANETs) can fill this gap. By leveraging on the distributed nature of ad hoc networks, accident warning systems can rapidly alert the vehicles which most risk their involvement in a crash. To reach this goal, VANET-based accident warning systems require the design of efficient broadcast algorithms. A number of solutions have been proposed in the past few years. However, no such proposals, to the best of our knowledge, assume realistic wireless propagation scenarios. The scope of this paper is to present an optimal distributed algorithm, working at the application layer, for the broadcast of safety messages in VANETs. Optimality, in terms of delay, is achieved in unidimensional highway scenarios and under realistic wireless propagation assumptions. This is the only algorithm, to this date, capable of reaching all vehicles with the minimum number of transmissions within a realistic setting.

A network coding based hybrid ARQ algorithm for wireless video broadcast

This paper proposes a network coding (NC) based hybrid ARQ (HARQ) algorithm for video broadcast over wireless networks. The sender applies NC technique to combine the lost packets of different terminals, so that multiple terminals can recover their lost packets via per transmission from the sender. The proposed algorithm combines the advantage of FEC scheme and NC based ARQ scheme so as to maximize not only wireless throughput but also video quality for broadcast communication. Simulation results show that our algorithm significantly improves both wireless throughput efficiency and video quality, compared with ARQ and HARQ schemes.

Evaluation of Selective Broadcast Algorithms for Safety Applications in Vehicular Ad Hoc Networks

Just as wireless communications develop further to achieve higher performance, new application areas emerge to challenge the limits. Vehicular ad hoc networks are one of these areas, and emergency situation warning is one of their most popular applications since traffic safety is a concern for everyone. Due to the life-critical nature of emergency applications, however, it is extremely important to ensure the solutions proposed meet the standards required, such as reliable and timely delivery of the safety warning in a situation like car collision avoidance. In order to put the candidate solutions to the test and evaluate their feasibility, we adopt the approach of computer simulation. We implement four different selective broadcast algorithms used for information dissemination in vehicular ad hoc networks, and compare their performance under identical realistic simulation conditions. Our goal is to provide an evaluation focussing on the performance with respect to safety, rather than to network aspects like throughput, loss, and delay. We define four new performance criteria to address the effectiveness, efficiency, timeliness, and overhead of the broadcast algorithms in safety warning delivery. The results we obtain using these criteria help us to understand better the design requirements of a high-performance selective broadcast algorithm.

Swarm Intelligence Approaches for Grid Load Balancing

With the rapid growth of data and computational needs, distributed systems and computational Grids are gaining more and more attention. The huge amount of computations a Grid can fulfill in a specific amount of time cannot be performed by the best supercomputers. However, Grid performance can still be improved by making sure all the resources available in the Grid are utilized optimally using a good load balancing algorithm. This research proposes two new distributed swarm intelligence inspired load balancing algorithms. One algorithm is based on ant colony optimization and the other algorithm is based on particle swarm optimization. A simulation of the proposed approaches using a Grid simulation toolkit (GridSim) is conducted. The performance of the algorithms are evaluated using performance criteria such as makespan and load balancing level. A comparison of our proposed approaches with a classical approach called State Broadcast Algorithm and two random approaches is provided. Experimental results show the proposed algorithms perform very well in a Grid environment. Especially the application of particle swarm optimization, can yield better performance results in many scenarios than the ant colony approach.

Analysis and simulation of a message dissemination algorithm for VANET

AbstractThis paper addresses the analytical evaluation of broadcast protocols in VANET. We focus on the most popular broadcast algorithm, which consists in the current emitter selecting the furthest receiver as the next forwarder. We propose a general framework based on point process to evaluate this protocol. The radio environment is modelled by a generic Frame Error Rate function. It enables us, through the same model, to assess the performances for different radio environments or radio technologies. We derive simple formulae for different quantities relative to the performance of the broadcast protocol: time to propagate the message, emitters' intensity, mean number of receptions for the same message, etc. Results based on the analytical model are compared with simulations using realistic vehicle traffic in order to determine the contexts for which the analytical model is relevant. Copyright © 2011 John Wiley & Sons, Ltd.

TMPR-scheme for reliably broadcast messages among peer processes

Nowadays information systems are being shifted to distributed architectures. The peer-to-peer (P2P) model as a fully distributed system, is composed of peer processes (peers). Here, peers have to efficiently and flexibly make an agreement on one common value which satisfies an agreement condition. In the agreement protocol, each peer has to deliver values to all the peers in a group. We take advantage of the multipoint relaying (MPR) mechanism to efficiently broadcast messages. Here, if a peer which forwards messages to other peers is faulty, the peers cannot receive messages. In this paper, we newly discuss a trustworthiness-based broadcast (TBB) algorithm where only the trustworthy peers forward messages. That is, untrustworthy peers, i.e., peers prone to faults and malicious behaviours do not forward messages. Here, the transmission fault implied by faulty peers can be reduced. We evaluate the TBB algorithm in terms of the number of messages compared with the pure flooding and MPR algorithms.

The impact of mobility on the time complexity for deterministic broadcasting in radio networks

We study the time complexity for deterministic broadcasting algorithms in mobile radio networks. The broadcast operation consists of a source node successfully communicating its message to every other node. In multi-hop radio networks such as MANETs, the message may traverse multiple other nodes. Nodes have no prior knowledge besides the number n of nodes in the network and its diameter D. The problem we address has been extensively studied for static networks. Our work quantifies the impact of mobility. We consider three families of graphs: undirected graphs of constant contention degree, undirected graphs of non-constant contention degree and directed graphs of non-constant contention degree. We prove the lower bounds of Ω(n log n) time slots for the first family, Ω(n²/D² log D + D) time slots for the second and Ω(n²/D² log D + n log D) for the third. At the time of writing, the corresponding tightest lower bounds derived in the static case are, respectively, Ω(D log n), Ω(n log/log n / D) and Ω(n log D).

Efficient broadcasting in multi-hop wireless networks with a realistic physical layer

Almost all existing broadcasting algorithms assume an ideal physical layer, in which a successful transmission is guaranteed if the distance between communicating nodes is less than a certain threshold, e.g., a transmission range. However, wireless communication links normally suffer from the characteristics of realistic physical layer, which significantly reduce the reliability of broadcasting among the nodes. This work addresses the minimal broadcasting problem in multi-hop wireless networks with a realistic physical layer. Given a probability p*, the problem is to design a distributed broadcasting algorithm such that each node in the network receives the broadcasting packet with probability no less than p* and the number of retransmissions is minimized. We show that this problem is NP-hard and propose a distributed greedy algorithm which maximizes the gain cost ratio at each node. We prove that the proposed algorithm guarantees that each node receives the broadcasting packet with probability no less than p*, and analyze upper bound on the number of total retransmissions in the network. Simulation results show that our algorithm can provide near 100% coverage to the wireless network with a realistic physical layer, and reduce the number of retransmissions compared with modified traditional flooding schemes k-Flooding (pure flooding with multiple times) and ACK-Flooding (pure flooding with acknowledgement). We believe our algorithmic solution is efficient and practical for general existing multi-hop wireless networks.

Realizing and benchmarking broadcast algorithms in wireless mesh networks

Broadcasting by flooding causes the broadcast storm problem in multi-hop wireless networks. This problem becomes more likely in a wireless mesh network (WMN) because WMNs can bridge wired LANs, increasing broadcast traffic and collision probability. Since the network control, routing, and topology maintenance of a WMN highly rely on layer-2 broadcasting, unreliable broadcast algorithms directly destabilize a WMN. Researchers have developed many algorithms for efficient and reliable broadcast in multi-hop wireless networks. However, real-world systems rarely verify or compare these approaches, especially in a WMN. This paper examines six representative broadcast algorithms: simple flooding, dynamic probabilistic, efficient counter-based broadcast, scalable broadcast, domain pruning, and connected-dominating-set based algorithms. This study addresses both common and algorithm-specific implementation in a real-world IEEE 802.11s WMN testbed. Experiments under various topologies and packet lengths reveal the reliability, forwarding ratio, and efficiency of these six algorithms. Quantitative survey results indicate that the scalable broadcast algorithm possesses the best reliability due to its lower collision probability. The domain-pruning algorithm is the most efficient algorithm when considering both reliability and the forwarding ratio.

Space-covered Broadcast Algorithm without Neighbor Information in Multi-hop Wireless Networks

Space-covered Broadcast Algorithm without Neighbor Information in Multi-hop Wireless Networks

The abstract MAC layer

A diversity of possible communication assumptions complicates the study of algorithms and lower bounds for radio networks. We address this problem by defining an abstract MAC layer. This service provides reliable local broadcast communication, with timing guarantees stated in terms of a collection of abstract delay functions applied to the relevant contention. Algorithm designers can analyze their algorithms in terms of these functions, independently of specific channel behavior. Concrete implementations of the abstract MAC layer over basic radio network models generate concrete definitions for these delay functions, automatically adapting bounds proven for the abstract service to bounds for the specific radio network under consideration. To illustrate this approach, we use the abstract MAC layer to study the new problem of Multi-Message Broadcast, a generalization of standard single-message broadcast in which multiple messages can originate at different times and locations in the network. We present and analyze two algorithms for Multi-Message Broadcast in static networks: a simple greedy algorithm and one that uses regional leaders. We then indicate how these results can be extended to mobile networks.

On the quality of broadcast services in vehicularad hocnetworks

AbstractWe investigate the broadcast problem in suburban and highway inter‐vehicular networks, aiming at providing a definitive comparison of two antipodean broadcast algorithm classes: the first one makes use of someinstantaneous informationlocally available at the vehicles (such as vehicle position and speed), while the second one relies onlong‐term knowledgegained through a beaconing procedure. Using a realistic microscopic model to represent the vehicular traffic flow, we investigate the performance of the above broadcast algorithm classes by simulation, considering different classes of network services (e.g., Critical, Normal, and Low‐priority). In order to explore a very large algorithmic design space, we devise a convex hull framework that allows us to effectively compare and compactly present the boundaries of the solution space for each algorithm class. By the use of such framework, we show that the beaconless performance encompasses a wider spectrum with respect to the beaconed one, with lower complexity and overhead. Copyright © 2010 John Wiley & Sons, Ltd.