Broadcast Operation Research Articles

PARP-S: A secure piggybacking-based ARP for IEEE 802.11s-based Smart Grid AMI networks

The Smart Grid is expected to utilize a wireless infrastructure for power data collection in its Advanced Metering Infrastructure (AMI) applications. One of the options to implement such a network infrastructure is to use a wireless mesh network based on IEEE 802.11s mesh standard. However, IEEE 802.11s standard relies on MAC-based routing and thus requires the availability of MAC addresses of destinations. Due to large size of AMI networks, this creates a broadcast storm problem when such information is to be obtained via Address Resolution Protocol (ARP) broadcast packets. In this paper, we propose a mechanism to significantly alleviate such broadcast storm problem in order to improve the scalability of 802.11s and thus make it better suited for Smart Grid AMI applications. Our contribution is adapting 802.11s standard for addressing ARP broadcast storm problem in a secure and efficient manner. Specifically, we utilize the proactive Path Request (PREQ) packet and Path Reply (PREP) of layer-2 path discovery protocol of 802.11s, namely HWMP, for piggybacking ARP information. In this way, the MAC address resolution is handled during routing tree creation/maintenance and hence the broadcasting of ARP requests by the smart meters (SMs) to learn the MAC address of the data collector (i.e., the gateway/root node) is completely eliminated. Furthermore, since piggybacking the ARP via PREQ may pose vulnerabilities for possible ARP cache poisoning attacks, the data collector also authenticates the messages it sends to SMs by using Elliptic Curve Digital Signature Algorithm (ECDSA). We have extensively analyzed the behavior and overhead of the proposed mechanism using implementation of IEEE 802.11s in ns-3 simulator. The evaluations for both UDP and TCP show that compared to the original ARP broadcast operations, our approach reduces the end-to-end delay significantly without negatively impacting the packet delivery ratio and throughput.

Benefits of Adding Hardware Support for Broadcast and Reduce Operations in MPSoC Applications

MPI has been used as a parallel programming model for supercomputers and clusters and recently in MultiProcessor Systems-on-Chip (MPSoC). One component of MPI is collective communication and its performance is key for certain parallel applications to achieve good speedups. Previous work showed that, with synthetic communication-only benchmarks, communication improvements of up to 11.4-fold and 22-fold for broadcast and reduce operations, respectively, can be achieved by providing hardware support at the network level in a Network-on-Chip (NoC). However, these numbers do not provide a good estimation of the advantage for actual applications, as there are other factors that affect performance besides communications, such as computation. To this end, we extend our previous work by evaluating the impact of hardware support over a set of five parallel application kernels of varying computation-to-communication ratios. By introducing some useful computation to the performance evaluation, we obtain more representative results of the benefits of adding hardware support for broadcast and reduce operations. The experiments show that applications with lower computation-to-communication ratios benefit the most from hardware support as they highly depend on efficient collective communications to achieve better scalability. We also extend our work by doing more analysis on clock frequency, resource usage, power, and energy. The results show reasonable scalability for resource utilization and power in the network interfaces as the number of channels increases and that, even though more power is dissipated in the network interfaces due to the added hardware, the total energy used can still be less if the actual speedup is sufficient. The application kernels are executed in a 24-embedded-processor system distributed across four FPGAs.

Tablet/Smart Phone Accelerated File-Based Broadcast Production

While there has been wide acceptance of file-based workflows in the consumer marketplace, professional production practices have been slow to follow. With an inherent distrust of all things computer-based, getting production companies to trust file-based acquisition and fully realize its potential has required a multifaceted solution to persuade people to embrace this new technology. This paper describes a real-world example of how these different facets of file-based acquisition can be brought together in a “perfect storm” with key new technologies to allow the broadcaster to fully embrace the file-based advantages. With metadata being key in realizing the full value of assets, the ability to put the creation of that metadata in the hands of operators who generate the asset is vital in ensuring that metadata is correct and comprehensive. By embracing new smartphone and tablet technology, we show how custom software allows the outside broadcast (OB) operator to quickly tag clips using Wi-Fi-based applications that fully integrate not only the onsite infrastructure, but also the end customers' archive and post-production facilities.

Energy-Efficient Algorithm for Broadcasting in Ad Hoc Wireless Sensor Networks

Broadcasting is a common and basic operation used to support various network protocols in wireless networks. To achieve energy-efficient broadcasting is especially important for ad hoc wireless sensor networks because sensors are generally powered by batteries with limited lifetimes. Energy consumption for broadcast operations can be reduced by minimizing the number of relay nodes based on the observation that data transmission processes consume more energy than data reception processes in the sensor nodes, and how to improve the network lifetime is always an interesting issue in sensor network research. The minimum-energy broadcast problem is then equivalent to the problem of finding the minimum Connected Dominating Set (CDS) for a connected graph that is proved NP-complete. In this paper, we introduce an Efficient Minimum CDS algorithm (EMCDS) with help of a proposed ordered sequence list. EMCDS does not concern itself with node energy and broadcast operations might fail if relay nodes are out of energy. Next we have proposed a Minimum Energy-consumption Broadcast Scheme (MEBS) with a modified version of EMCDS, and aimed at providing an efficient scheduling scheme with maximized network lifetime. The simulation results show that the proposed EMCDS algorithm can find smaller CDS compared with related works, and the MEBS can help to increase the network lifetime by efficiently balancing energy among nodes in the networks.

A Combined Approach for Implementation of Broadcast Operation in Grid Computing

In distributed computing, the collective communications scheduling is among the most important scheduling problems related to intensive applications executed over heterogeneous platforms. The optimization of collective operations allows the improvement of parallel and distributed applications performance by reducing the completion time of these operations. In this paper, the authors are particularly interested by the optimization of broadcast operation executed over large scale distributed environment such as grid computing. For this aim, we combined the two levels approach implemented in MagPIe library proposed for the hierarchical large scale systems with the ECEF (Earliest Completion Edge First) heuristic proposed for the IPG (Information Power Grid). Simulation results show the advantage of our proposed hybrid strategy compared to the classical ECEF heuristic.

Deadlock Recovery Technique in Bus Enhanced NOC Architecture

Increase in the speed of processors has led to crucial role of communication in the performance of systems. As a result, routing is taken into consideration as one of the most important subjects of the Network on Chip architecture. Routing algorithms to deadlock avoidance prevent packets route completely based on network traffic condition by means of restricting the route of packets. This action leads to less performance especially in non-uniform traffic patterns. On the other hand True Fully Adoptive Routing algorithm provides routing of packets completely based on traffic condition. However, deadlock detection and recovery mechanisms are needed to handle deadlocks. Use of global bus beside NoC as a parallel supportive environment, provide platform to offer advantages of both features of bus and NoC. This bus is useful for broadcast and multicast operations, sending delay sensitive signals, system management and other services. In this research, we use this bus as an escaping path for deadlock recovery technique. According to simulation results, this bus is suitable platform for deadlock recovery technique.

Enhancing Performance of Duo Coverage Broadcasting in MANET

In today’s developing environment in the field of Mobile Ad hoc Network, broadcast reliability plays vital role. In MANET when the forwarding nodes are not carefully designated, they are prone to the broadcast storm. To avoid the problem of broadcast storm, the Double Coverage Broadcasting (DCB) algorithm is introduced. The proposed scheme increases the delivery ratio though the redundancy is reduced. Other factors under consideration is that the proposed scheme has high delivery ratio, low forwarding ratio, low overhead and low end-to-end delay for a broadcast operation under a high transmission error rate. Among the 1-hop neighbours of the sender, only selected forwarding nodes retransmit the broadcasting the message. Forwarding nodes are selected in such a way that 1) the sender’s 2-hop neighbours are covered and 2) the sender’s 1-hop neighbours are either forwarding nodes or nonforwarding nodes covered by at least two forwarding neighbours. The retransmissions of the forwarding nodes are received by the sender as the confirmation of their reception of the packet. The nonforwarding 1-hop neighbours of the sender do not acknowledge the reception of the broadcast. If the sender does not detect all its forwarding nodes’ retransmissions, it will resend the packet until the maximum number of retries is reached.

무선 센서 네트워크에서 최소 전력 브로드캐스트 문제를 위한 최적화 알고리즘

무선 네트워크에서 최소 에너지 브로드캐스트 문제는 네트워크에 배치된 모든 노드가 브로드캐스팅과정에서 데이터 전송에 사용되는 에너지를 최소화하는 문제이다. 본 논문은 무선 센서 네트워크에서 최소 에너지 브로드캐스트 문제를 효과적으로 해결할 수 있는 메타휴리스틱 기법인 타부서치 알고리즘을 제안한다. 보다 효과적인 해 검색을 위해 제안된 알고리즘은 새로운 이웃해 생성방식과 복구함수를 적용한다. 제안된 알고리즘의 성능평가는 배치된 모든 노드로의 브로드캐스팅 시 전송 에너지와 알고리즘 실행시간 관점에서 기존의 알고리즘과 비교를 하였으며, 실험 결과에서 제안된 알고리즘이 최소 에너지 브로드캐스트 문제에 효과적으로 적용됨을 보여준다. The minimum energy broadcast problem is for all deployed nodes to minimize a total transmission energy for performing a broadcast operation in wireless networks. In this paper, we propose a Tabu search algorithm to solve efficiently the minimum energy broadcast problem on the basis of meta-heuristic approach in wireless sensor networks. In order to make a search more efficient, we propose a novel neighborhood generating method and a repair function of the proposed algorithm. We compare the performance of the proposed algorithm with other existing algorithms through some experiments in terms of the total transmission energy of nodes and algorithm computation time. Experimental results show that the proposed algorithm is efficient for the minimum energy broadcast problem in wireless sensor networks.

Fast Response PKC-Based Broadcast Authentication in Wireless Sensor Networks

Public Key-based (PKC) approaches have gained popularity in Wireless Sensor Network (WSN) broadcast authentication due to their simpler protocol operations, e.g., no synchronization and higher tolerance to node capture attack compared to symmetric key-based approaches. With PKC's security strength, a sensor node that authenticates messages before forwarding them can detect a bogus message within the first hop. While this prevents forged traffic from wasting the sensor nodes' energy, performing PKC operations in the limited computing-power sensor nodes can result in undesirably long message propagation time. At the other extreme, the sensor node can forward messages to other nodes prior to authenticating them. This approach diminishes propagation time with the trade-off of allowing forged messages to propagate through the network. To achieve swift and energy efficient broadcast operation, sensor nodes need to decide wisely when to forward first and when to authenticate first. In this paper, we present two new broadcast authentication schemes, called the key pool scheme and the key chain scheme, to solve this dilemma without any synchronization or periodic key redistribution. Both schemes utilize a Bloom filter and the distribution of secret keys among sensor nodes to create fast and capture-resistant PKC-based broadcast authentication protocols. Our NS-2 simulation results for a 3,000-node WSN confirm that broadcast delays of our protocol are only 46.7% and 39.4% slower than the forwarding-first scheme for the key pool and the key chain scheme respectively. At the same time, both protocols are an order of magnitude faster than the authentication-first scheme. The key pool scheme is able to keep forged message propagation to the minimal even when the majority of the nodes have been captured by the attacker. The key chain scheme has smaller transmission overhead than the key pool scheme at the expense of less resistance to node capturing. Two generic improvements to these schemes are also described. One reduces the marking limit on the Bloom filter vector (BFV), which makes it more difficult for an attacker to forge a BFV for a bogus message. The other limits broadcast forwarding to a spanning tree, which reduces the number of nodes forwarding bogus messages by one to two orders of magnitude depending on the percentage of compromised nodes. The first improvement can be applied to any BFV scheme, while the second is even more generally applicable.

Cache invalidation strategies for Internet-based vehicular ad hoc networks

Internet-based vehicular ad hoc network ( Ivanet) is an emerging technique that combines a wired Internet and a vehicular ad hoc network ( Vanet) for developing an ubiquitous communication infrastructure and improving universal information and service accessibility. A key design optimization technique in Ivanets is to cache the frequently accessed data items in a local storage of vehicles. Since vehicles are not critically limited by the storage/memory space and power consumption, selecting proper data items for caching is not very critical. Rather, an important design issue is how to keep the cached copies valid when the original data items are updated. This is essential to provide fast access to valid data for fast moving vehicles. In this paper, we propose a cooperative cache invalidation (CCI) scheme and its enhancement (ECCI) that take advantage of the underlying location management scheme to reduce the number of broadcast operations and the corresponding query delay. We develop an analytical model for CCI and ECCI techniques for fasthand estimate of performance trends and critical design parameters. Then, we modify two prior cache invalidation techniques to work in Ivanets: a poll-each-read (PER) scheme, and an extended asynchronous (EAS) scheme. We compare the performance of four cache invalidation schemes as a function of query interval, cache update interval, and data size through extensive simulation. Our simulation results indicate that the proposed schemes can reduce the query delay up to 69% and increase the cache hit rate up to 57%, and have the lowest communication overhead compared to the prior PER and EAS schemes.

Optimizing Method for Improving the Performance of MPI Broadcast under Unbalanced Process Arrival Patterns

PDF HTML阅读 XML下载 导出引用 引用提醒 非平衡进程到达模式下MPI广播的性能优化方法 DOI: 10.3724/SP.J.1001.2011.03915 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学创新群体基金(60621003) Optimizing Method for Improving the Performance of MPI Broadcast under Unbalanced Process Arrival Patterns Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了提高非平衡进程到达(unbalanced process arrival,简称UPA)模式下MPI广播的性能,对UPA模式下的广播问题进行了理论分析,证明了在多核集群环境中通过节点内多个MPI 进程的竞争可以有效减少UPA 对MPI广播性能的影响,并在此基础上提出了一种新的优化方法,即竞争式流水化方法(competitive and pipelined method,简称CP).CP方法通过一种节点内进程竞争机制在广过程中尽早启动节点间通信,经该方法优化的广播算法利用共享内存在节点内通信,利用由竞争机制产生的引导进程执行原算法在节点间通信.并且,该方法使节点间通信和节点内通信以流水方式重叠执行,能够有效利用集群系统各节点的多核优势,减少了MPI广播受UPA的影响,提高了性能.为了验证CP方法的有效性,基于此方法优化了3种典型的MPI广播算法,分别适用于不同消息长度的广播.在真实系统中,通过微基准测试和两个实际的应用程序对CP广播进行了性能评价,结果表明,该方法能够有效地提高传统广播算法在UPA模式下的性能.在应用程序的负载测试实验结果中,CP广播的性能较流水化广播的性能提高约16%,较MVAPICH2 1.2中广播的性能提高18%~24%. Abstract:This paper aims at improving the performance of MPI broadcasts under unbalanced process arrival (UPA) patterns. This paper analyzes this problem with a performance model and proves that the negative impact of UPA on MPI broadcast can be effectively reduced by the competition of intra-node MPI processes on a multicore cluster. Based on this theory, a new optimizing method, called competitive and pipelined method (CP), is proposed. The CP method can start inter-node communications during the broadcast process through an intra-node competitive mechanism. In a CP method based broadcast algorithm, intra-node communications overlap inter-node communications through a pipelined method, and intra-node communications are implemented through shared memory while inter-node communications are executed by a set of leader MPI processes, which is selected by the competitive mechanism. In order to verify the CP method, this paper improves three typical broadcast algorithms by using this method and evaluates these algorithms in a real platform by using a micro-benchmark case and two practical applications. The results show that the performance of the CP method can effectively improve the performance of broadcast algorithms in the condition of UPA patterns. In the experimental results of the performance of the practical applications, the performance of CP broadcasts is about 16% higher than the performance of P broadcasts and is 18% to 24% higher than the performance of broadcast operation in MVAPICH2 1.2. 参考文献 相似文献 引证文献

Darkness at the Heart of Recent Italian Literature

Darkness at the Heart of Recent Italian Literature

Evolutionary Neural Networks algorithm for the Dynamic Frequency Assignment Problem

Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, wireless LANs, and military operations. In each of these situations a frequency assignment problem arises with application-specific characteristics. Researchers have developed different modelling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This paper presents a new approach for solving the problem of frequency allocation based on using initially a partial solution respecting all constraints according to a greedy algorithm. This partial solution is then used for the construction of our stimulation in the form of a neural network. In a second step, the approach will use searching techniques used in conjunction with iterative algorithms for the optimization of the parameters and topology of the network. The iterative algorithms used are named hierarchical genetic algorithms (HGA). Our approach has been tested on standard benchmark problems called Philadelphia problems of frequency assignment. The results obtained are equivalent to those of current methods. Moreover, our approach shows more efficiency in terms of flexibility and autonomy.

Min-energy broadcast in mobile ad hoc networks with restricted motion

This paper concerns about energy-efficient broadcasts in mobile ad hoc networks, yet in a model where each station moves on the plane with uniform rectilinear motion. Such restriction is imposed to discern which issues arise from the introduction of movement in the wireless ad hoc networks. Given a transmission range assignment for a set of n stations S, we provide an polynomial O(n 2)-time algorithm to decide whether a broadcast operation from a source station could be performed or not. Additionally, we study the problem of computing a transmission range assignment for S that minimizes the energy required in a broadcast operation. An O(n 3log?n)-time algorithm for this problem is presented, under the assumption that all stations have equally sized transmission ranges. However, we prove that the general version of such problem is NP-hard and not approximable within a (1?o(1))ln?n factor (unless NP?DTIME(n O(log?log?n))). We then propose a polynomial time approximation algorithm for a restricted version of that problem.

Efficient and Scalable Routing Algorithms for Collective Communication Operations on 2D All-Port Torus Networks

Collective Communication Algorithms for 2D torus networks have been investigated quite extensively in the literature and two broad approaches, namely direct methods and indirect (message combining) methods are recognized in the field. While direct methods minimize the volume of data, the indirect methods reduce the number of message start-ups. Consequently, either a suite of algorithms must be employed for efficiency over a wide range of message lengths and communication operations or algorithms should be able to adapt themselves to the current case, possibly by switching between direct and indirect routing modes as appropriate. In this paper, we propose adaptive routing algorithms for all-port, wormhole routed, synchronous, 2D torus networks optimized for one-to-all broadcast, gossiping and complete exchange collective communication operations. The proposed algorithms employ completely-connected subnetworks where complete exchange amongst the nodes in the subnetwork can be accomplished in one step only. Combined with suitable 2D plane tiling techniques, the proposed algorithms share the same set of primitive operations and yield superior performance compared to previously proposed methods, either pure or hybridized.

Maximizing the Number of Broadcast Operations in Random Geometric Ad Hoc Wireless Networks

We consider static ad hoc wireless networks whose nodes, equipped with the same initial battery charge, may dynamically change their transmission range. When a node v transmits with range r(v), its battery charge is decreased by β r(v)2, where β > 0 is a fixed constant. The goal is to provide a range assignment schedule that maximizes the number of broadcast operations from a given source (this number is denoted by the length of the schedule). This maximization problem, denoted by Max LifeTime, is known to be NP-hard and the best algorithm yields worst-case approximation ratio Θ (log n), where n is the number of nodes of the network. We consider random geometric instances formed by selecting n points independently and uniformly at random from a square of side length √n in the euclidean plane. We present an efficient algorithm that constructs a range assignment schedule having length not smaller than 1/12 of the optimum with high probability. Then we design an efficient distributed version of the above algorithm, where nodes initially know n and their own position only. The resulting schedule guarantees the same approximation ratio achieved by the centralized version, thus, obtaining the first distributed algorithm having provably good performance for this problem.

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).

On the performance of scalable video coding for VBR TV channels transport in multiple resolutions and qualities

Video broadcast operators target a variety of receiving devices of different resolutions and processing capabilities. In such a heterogeneous TV network, the transport resource consumption is likely to increase. In this paper we estimate the required transport capacity for a broadcast TV network taking into account parameters as currently proposed in standardization bodies. We target constant video quality, hence the TV channel has variable bit rate (VBR). We consider a multicast-based transport system where only the required versions of a TV channel are transported; this leads to fluctuation of the consumed transport capacity over time. The main focus in this paper is on the comparison of a simulcast and a scalable video coding (SVC) transport scheme in several realistic examples with different encoding modes, including spatial and/or quality scalability. To estimate the required transport capacity for simulcast and SVC, we use a comprehensive toolkit based on a Gaussian approximation of the capacity demand. In order to obtain realistic input values for our calculation tools, we characterize the fluctuations of the bit rate associated with a TV channel by encoding a representative set of video clips. Based on the considered realistic examples, we explore under what conditions either the simulcast or the SVC transport scheme is more efficient.

Mobile TV services through IP Datacast over DVB-H: Dependability of the quality of experience on the IP-based distribution network quality of service

The Digital Video Broadcast-Handheld (DVB-H) is an international standard which offers broadcast data services to mobile handheld devices. Its main enhancements to conventional Digital Video Broadcast-Terrestrial (DVB-T) systems include the addition of time-slicing and an extra stage of error correction, referred to as Multi-Protocol Encapsulation-Forward Error Correction (MPE-FEC) at the link layer. The essential components required to deploy an IP-based mobile TV service on top of DVB-H are described by the DVB standard for IP DataCast specifications (DVB-IPDC). Since mobile TV services mostly consist of real-time video data, very stringent demands in terms of quality of service (QoS) are imposed to the broadcast operator's primary distribution network. In this article, the impact of packet loss, introduced in a IP-based distribution network, on the quality of experience (QoE), the video quality as perceived by the end user, is characterised. In recent work, a first analysis of the impact of random packet loss was reported upon. This paper describes a more profound analysis of both random and burst packet loss by taking into account several objective video quality metrics. It is shown that, although MPE-FEC is introduced for better reception between antenna and receiver, its use has a major impact on the effects of packet loss in the distribution network. The use of error-correction techniques in the distribution network only has a beneficial impact on the QoE when lower MPE-FEC code rates are used. Moreover, the impact of action scenes or scene switches on the perceived video quality is also characterised in detail. Based on the experimental results, an analytical model is presented which allows to predict the QoE detoriation as a function of the burst loss probability in the distribution network.

Reliable and Efficient Algorithm for Broadcasting in Asymmetric Mobile Ad hoc Networks

Network wide broadcasting is a fundamental operation in ad hoc networks. In broadcasting, a source node sends a message to all the other nodes in the network. Unlike in a wired network, a packet transmitted by a node in ad hoc wireless network can reach all neighbors. Therefore, the total number of transmissions (Forwarding nodes) used as the cost criterion for broadcasting. The broadcast operation, as a fundamental service in mobile ad hoc networks (MANETs), is prone to the broadcast storm problem if forwarding nodes are not carefully designated. The forward node selection has been studied extensively in undirected graphs in which each node has the same transmission range. In practice, the transmission ranges of all nodes are not necessarily equal. This thesis proposes a reliable and efficient localized broadcasting algorithm using 2-hop neighborhood information more effectively to reduce redundant transmissions in asymmetric Mobile Ad hoc networks that guarantees full delivery. Among the 1-hop neighbors of the sender, only selected forwarding nodes retransmit the broadcast message. Forwarding nodes are selected such a way that to cover the uncovered 2-hop neighbors. The retransmissions of the forwarding nodes are received by the sender as the confirmation of their reception of the packet. The non forwarding 1-hop neighbors of the sender only acknowledge the reception of the broadcast. If the sender does not detect all its forwarding nodes retransmissions and non forwarding nodes acknowledgements, it will resend the packet until the maximum number of retries is reached. Simulation results show that the proposed broadcast algorithm provides good broadcast delivery ratio with low overhead and minimum latency.