Broadcast Problem Research Articles

Minimum energy broadcast on rectangular grid wireless networks

The minimum energy broadcast problem is to assign a transmission range to each node in an ad hoc wireless network to construct a spanning tree rooted at a given source node such that any non-root node resides within the transmission range of its parent. The objective is to minimize the total energy consumption, i.e., the sum of the δ th powers of a transmission range ( δ ≥ 1 ). In this paper, we consider the case that δ = 2 , and that nodes are located on a 2-dimensional rectangular grid. We prove that the minimum energy consumption for an n -node k × l -grid with n = k l and k ≤ l is at most n π + O ( n k 0.68 ) and at least n π + Ω ( n k ) − O ( k ) . Our bounds close the previously known gap of upper and lower bounds for square grids. Moreover, our lower bound is n 3 − O ( 1 ) for 3 ≤ k ≤ 18 , which matches a naive upper bound within a constant term for k ≡ 0 ( mod 3 ) .

Mobility and Load aware Routing protocol for ad hoc networks

Mobile ad hoc networks (MANETs) are very promising wireless technology and they offer wide range of possibilities for the future in terms of applications and coverage. Due to the complex nature of MANETS, their development processes face several challenges such as routing. Many routing algorithms have been proposed for MANETs. Reactive routing protocols are favored and popular in MANETs because they are more scalable and generate fewer overhead on the network. But, these protocols suffer from the broadcast storm problem due to the flooding strategy that is used in the route discovery process which causes redundancy, contention and collision problems. In order to reduce the effects of the broadcast problem, a Mobility and Load aware Routing scheme (MLR) is proposed in this paper. MLR controls the flooding process by restricting the rebroadcast messages on the slow speed and low loaded nodes. Each node decides whether to forward or drop the received request message based on several factors (such as speed and routing load) using Markovian Decision Process tool. Simulation results show that MLR scheme outperforms the original AODV protocol in terms of normalized routing load and average end-to-end delay.

Minimum energy broadcasting in wireless sensor networks: An ant colony optimization approach for a realistic antenna model

Abstract The classical minimum energy broadcast (MEB) problem in wireless adhoc networks, which is well-studied in the scientific literature, considers an antenna model that allows the adjustment of the transmission power to any desired real value from zero up to the maximum transmission power. However, when specifically considering sensor networks, a look at the currently available hardware shows that this antenna model is not very realistic. A first contribution of this work is therefore the re-formulation of the MEB problem for an antenna model that is realistic for sensor networks. In this antenna model transmission power levels are chosen from a finite set of possible ones. The second contribution concerns the adaptation of ant colony optimization, a current state-of-the-art algorithm for the classical MEB problem, to the more realistic problem version. The obtained results show that the advantage of ant colony optimization over classical heuristics even grows when the number of possible transmission power levels decreases.

Latent Capacity Region: A Case Study on Symmetric Broadcast With Common Messages

We consider the problem of broadcast with common messages, and focus on the case that the common message rate <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RA</i> , i.e., the rate of the message intended for all the receivers in the set <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">A</i> , is the same for all the set <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">A</i> of the same cardinality. Instead of attempting to characterize the capacity region of general broadcast channels, we only consider the structure of the capacity region that any broadcast channel should bear. The concept of latent capacity region is useful in capturing these underlying constraints, and we provide a complete characterization of the latent capacity region for the symmetric broadcast problem. The converse proof of this tight characterization relies on a deterministic broadcast channel model. The achievability proof generalizes the familiar rate transfer argument to include more involved erasure correction coding among messages, thus revealing an inherent connection between broadcast with common message and erasure correction codes.

Improved lower bound for deterministic broadcasting in radio networks

We consider the problem of deterministic broadcasting in radio networks when the nodes have limited knowledge about the topology of the network. We show that for every deterministic broadcasting protocol there exists a network, of radius 2, for which the protocol takes at least Ω ( n 1 2 ) rounds for completing the broadcast. Our argument can be extended to prove a lower bound of Ω ( ( n D ) 1 2 ) rounds for broadcasting in radio networks of radius D . This resolves one of the open problems posed in Kowalski and Pelc (2004) [24], where the authors proved a lower bound of Ω ( n 1 4 ) rounds for broadcasting in constant diameter networks. We prove the new lower bound for a special family of radius 2 networks. Each network of this family consists of O ( n ) components which are connected to each other via only the source node. At the heart of the proof is a novel simulation argument, which essentially says that any arbitrarily complicated strategy of the source node can be simulated by the nodes of the networks, if the source node just transmits partial topological knowledge about some component instead of arbitrary complicated messages. To the best of our knowledge this type of simulation argument is novel and may be useful in further improving the lower bound or may find use in other applications.

On-line genetic programming of multi-hop broadcast protocols in ad hoc networks

From the family of ad hoc communication protocols the most challenging ones are those, that are designed to disseminate messages to all, or most of the nodes in the system. By their nature, these kinds of protocols use significant network resources, as the communication must involve a large fraction of the network nodes. Reducing the network load can be achieved by using the available local broadcast medium (radio channel), but it is not trivial how to select the set of nodes that should participate in the dissemination process. Previous attempts delivered algorithms that can provide reasonable performance and reliability but mostly for specific cases of ad hoc networks. In this paper a new way of tackling the broadcast problem is presented that takes no assumptions about the nature of the underlying network. Instead of using hand-optimizing protocols, we propose a framework for a self-optimizing and self-managing system inspired by natural selection and evolution. A generic distributed feed-forward performance evaluation criterion based on natural selection is presented along with an implementation of a virtual machine and a corresponding language for Genetic Programming to be used in tandem with the natural selection process.

TLDP: A New Broadcast Scheduling Scheme for Multiple Broadcast-Channel Environments

Broadcast-based data dissemination has become a widely accepted approach of communication in the mobile computing environment. However, with a large set of data items, the expected delay of receiving a desired data increases due to the sequential nature of the broadcast channel. With the objective of minimizing this wait time, this paper explores the problem of data broadcast over multiple channels. In traditional approaches, data items are partitioned based on their access probabilities and allocated on multiple channels, assuming flat data scheduling per channel. If the data items allocated on the same channel are broadcast in different frequencies based on their access probabilities, the performance will be enhanced further. In this respect, this paper proposes a new broadcast scheduling scheme named two level dynamic programming(TLDP) which can reflect a variation of access probabilities among data items allocated on the same channel.

A Linear Programming-based Evolutionary Algorithm for the Minimum Power Broadcast Problem in Wireless Sensor Networks

A matheuristic approach, where concepts from linear programming are integrated into an evolutionary algorithm, is proposed. It is tested on a problem arising in wireless sensor networks: a topology with minimum total power expenditure, that connects a source node to all the other nodes of the network, has to be identified. Experimental results are presented.

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.

Extreme value FEC for reliable broadcasting in wireless networks

The advent of practical rateless codes enables implementation of highly efficient packet-level forward error correction (FEC) strategies for reliable data broadcasting in loss-prone wireless networks, such as sensor networks. Yet, the critical question of accurately quantifying the proper amount of redundancy has remained largely unsolved. In this paper, we exploit advances in extreme value theory to rigorously address this problem. Under the asymptotic regime of a large number of receivers, we derive a closed-form expression for the cumulative distribution function (CDF) of the completion time of file distribution. We show the existence of a phase transition associated with this CDF and accurately locate the transition point. We derive tight convergence bounds demonstrating the accuracy of the asymptotic estimate for the practical case of a finite number of receivers. Further, we asymptotically characterize the CDF of the completion time under heterogeneous packet loss, by establishing a close relationship between the data broadcasting and multi-set coupon collector problems. We demonstrate the benefits of our approach through simulation and through real experiments on a Tmote Sky sensor testbed. Specifically, we augment the existing Rateless Deluge software dissemination protocol with an extreme value FEC strategy. The experimental results reveal reduction by a factor of five in retransmission request messages and by a factor of two in total dissemination time, at the cost of a marginally higher number of data packet transmissions in the order of 5%.

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 &amp; Sons, Ltd.

DNA algorithm employing temperature gradient for Freeze-Tag Problem in swarm robotics

The biological deoxyribonucleic acid (DNA) strand is found to be a promising computing unit. An attempt has been made to solve Freeze-Tag Problem (FTP) using DNA. In this paper, the thermodynamic properties of DNA have been utilized along with other biochemical operations to obtain the optimal awakening schedule. Actual distance values are represented using the thermodynamic properties of DNA. The proposed method also finds the minimum spanning tree (MST) of the FTP to obtain the optimal awakening schedule. All possible Euler cycles of the different spanning trees of the problem are first generated. From this generated Euler cycle, the MST is obtained, which is the optimal awakening schedule to the problem. Moreover, the proposed approach can be adopted to solve many real-life applications like broadcasting and scheduling problems, with necessary modifications. In this work, an instance with seven robots is solved using DNA computing.

Minimum-Outage Broadcast in Wireless Networks with Fading Channels

We consider the problem of cooperative broadcasting for minimum outage in wireless networks. We consider wireless multihop broadcast as a set of transmitters that transmit in a certain order. The receiving nodes are able to combine all the previous transmissions and achieve better received SNR. We consider the problem of finding the optimal set and order of (fixed-power) transmitters that minimizes the overall outage probability in a wireless fading channel. We found the optimal solution using a Branch-and-Bound approach and proposed some suboptimal algorithms. The numerical results show that a simple algorithm that we propose performs surprisingly well.

Reliable Broadcast in Radio Networks with Locally Bounded Failures

This paper studies the reliable broadcast problem in a radio network with locally bounded failures. We present a sufficient condition for achievability of reliable broadcast in a general graph subject to Byzantine/crash-stop failures. We then consider the problem of reliable broadcast in an infinite grid (or finite toroidal) radio network under Byzantine and crash-stop failures. We present bounds on the maximum number of failures that may occur in any given neighborhood without rendering reliable broadcast impossible. For the Byzantine failure model, we describe an algorithm which is optimal for the grid network model, as it tolerates faults up to a previously established upper bound for this model. Our results indicate that it is possible to achieve reliable broadcast if slightly less than one-fourth fraction of nodes in any neighborhood are faulty. We also show that reliable broadcast is achievable with crash-stop failures if slightly less than half the nodes in any given neighborhood may be faulty.

An efficient approximation for minimum latency broadcast in multi-channel multi-hop wireless networks

In this paper, we discuss the minimum latency broadcast problem (MLB) in multi-channel multi-hop wireless networks (MLB-MC). This problem is NP-hard since its special version, MLB in single-channel network (MLB-SC) is proved to be NP-hard . We design an efficient approximation for MLB-MC, analyze its approximation ratio, and evaluate its performance via numerical experiments. Furthermore, we give a general theorem as an upper bound to compare the performance between approximations for MLB-MC and MLB-SC.

Efficient multi-hop scheduling algorithms for packet transmissions in WDM optical star networks

This paper proposes multi-hop scheduling algorithms for the All-to-All Broadcast (AAB) problem in Wavelength Division Multiplexed (WDM) optical star networks. The multi-hop AAB problem can be split into two subproblems: Logical Topologies Construction (LTC) problem, and Transmission Scheduling (TS) problem. For improving the efficiency of multi-hop scheduling, we focus on a new multi-hop transmission model and transfer the LTC problem to a special case of the Round Robin Tournament (RRT) problem. In the proposed logical topologies, our multi-hop scheduling algorithms can easily overlap the tuning latency and reduce the number of tuning operations on each node. We compare our results with previous research in terms of schedule length. Overall results indicate that our multi-hop scheduling algorithms have better performance than previous algorithms.

Minimum-Transmission Broadcast in Uncoordinated Duty-Cycled Wireless Ad Hoc Networks

Broadcast is a fundamental operation of wireless ad hoc networks (WANETs) and has widely been studied over the past few decades. However, most existing broadcasting strategies assume nonsleeping wireless nodes and thus are not suitable for uncoordinated duty-cycled WANETs, in which each node periodically switches on and off to save energy. In this paper, we study the minimum-transmission broadcast problem in uncoordinated duty-cycled WANETs (MTB-UD problem) and prove its NP-hardness. We show that modifications of existing broadcast approaches can only provide a linear approximation ratio of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> ) (where <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> is the number of nodes in the network). We propose a novel set-cover-based approximation (SCA) scheme with both centralized and distributed approximation algorithms. The centralized SCA (CSCA) algorithm has a logarithmic approximation ratio of 3(ln ¿ + 1) and time complexity of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ) (¿ is the maximum degree of the network). The distributed SCA (DSCA) algorithm has a constant approximation ratio of at most 20 while keeping both linear time and message complexities. We have conducted both theoretical analysis and simulations to evaluate the performance of the proposed algorithms. Results show that both the CSCA and DSCA algorithms outperform the modified versions of existing broadcast approaches by at least 50%.

Integer Programming Formulations for Maximum Lifetime Broadcasting Problems in Wireless Sensor Networks

Approaches based on integer linear programming have been recently proposed for topology optimization in wireless sensor networks. They are, however, based on over-theoretical, unrealistic models. Our aim is to show that it is possible to accommodate realistic models for energy consumption and communication protocols into integer linear programming. We analyze the maximum lifetime broadcasting topology problem and we present realistic models that are also shown to provide efficient and practical solving tools. We present a strategy to substantially speed up the convergence of the solving process of our algorithm. This strategy introduces a practical drawback, however, in the characteristics of the optimal solutions retrieved. A method to overcome this drawback is discussed. Computational experiments are reported.

A hybrid genetic algorithm for the minimum energy broadcast problem in wireless ad hoc networks

Given a wireless ad hoc network with a specified source node that has to broadcast messages to all other nodes in the network, the minimum energy broadcast (MEB) problem seeks a broadcast scheme for this network with minimum energy consumption. The MEB problem is NP-Hard. This paper describes a hybrid approach to the MEB problem combining a genetic algorithm with a local search heuristic. We have compared our hybrid approach against the best heuristic approaches known for this problem. Our approach outperformed all these approaches and emerged as the best.

Efficient secret broadcast in the broadcasting networks

One of the basic problems in the broadcasting networks is a secret broadcast problem. The problem is how to securely send a message to the receivers while guaranteeing consistency. Consistency means that each receiver can assure that all of the receivers have received the same message. In other words, secret broadcast guarantees that a sender cannot broadcast a secret message to the receivers in a way that each receiver receives a different secret message. In the paper, we suggest an efficient secret broadcast scheme using binding encryption in the broadcasting networks.