Proposed Broadcast Algorithm Research Articles

Efficient Pipelined Broadcast with Monitoring Processing Node Status on a Multi-Core Processor

This paper presents an efficient pipelined broadcasting algorithm with the inter-node transmission order change technique considering the communication status of processing nodes. The proposed method changes the transmission order for the broadcast operation based on the communication status of processing nodes. When a broadcast operation is received, a local bus checks the remaining pre-existing transmission data size of each processing node; it then transmits data according to the changed transmission order using the status information. Therefore, the synchronization time can be hidden for the remaining time, until the pre-existing data transmissions finish; as a result, the overall broadcast completion time is reduced. The simulation results indicated that the speed-up ratio of the proposed algorithm was up to 1.423, compared to that of the previous algorithm. To demonstrate physical implementation feasibility, the message passing engine (MPE) with the proposed broadcast algorithm was designed by using Verilog-HDL, which supports four processing nodes. The logic synthesis results with TSMC 0.18 μm process cell libraries show that the logic area of the proposed MPE is 2288.1 equivalent NAND gates, which is approximately 2.1% of the entire chip area. Therefore, performance improvement in multi-core processors is expected with a small hardware area overhead.

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.

Density Based Routing Algorithm for Spare/Dense Topologies in Wireless Mobile Ad-Hoc Networks

Problem statement: A Mobile Ad-Hoc Networks (MANETs) operate in environments without infrastructures with an undefined network size. Most routing protocols of Mobile Ad-hoc Networks (MANETs) were studied using open space models where nodes were able to move throughput the entire simulation area. However, a more realistic topology should account for restricted mobility of nodes, such as in an urban city setting where there may be concentrations of nodes within specific areas (such as within buildings) and low density of nodes in other areas (such as in parks and roadways). Consequently, the simulation area should be partitioned into smaller sub-areas with varying densities to model such topologies, called spare/dense topologies. Approach: This study characterized the effect of spare/dense topologies on MANET routing performance and proposes an extension for an existing routing protocol to work in such topologies. Results: The proposed protocol improved the performance of MANETs by reducing the communication overhead incurred during the routing processes by implementing a new broadcast algorithm. The proposed broadcast algorithm was based on the density and connectivity of the nodes and not just the number of nodes. Conclusion: Compared with simple flooding, the proposed algorithm can improve the saved broadcast up to 50% without affecting reach ability, even under conditions of high mobility and density.

Localized Broadcasting with Guaranteed Delivery and Bounded Transmission Redundancy

The common belief is that localized broadcast algorithms are not able to guarantee both full delivery and a good bound on the number of transmissions. In this paper, we propose the first localized broadcast algorithm that guarantees full delivery and a constant approximation ratio to the minimum number of required transmissions in the worst case. The proposed broadcast algorithm is a self-pruning algorithm based on one round of information exchange. Using the proposed algorithm, each node determines its forwarding status in O(D logD), where D is the maximum node degree of the network. By extending the proposed algorithm, we show that localized broadcast algorithms can achieve both full delivery and a constant approximation ratio to the optimum solution with message complexity O(N), where N is the total number of nodes in the network and each message contains a constant number of bits. We also show how to save bandwidth by reducing the size of piggybacked information. Finally, we relax several system-model assumptions, or replace them with practical ones, in order to improve the practicality of the proposed broadcast algorithm.

Client-Side Caching Strategies and On-Demand Broadcast Algorithms for Real-Time Information Dispatch Systems

In this work, we propose a broadcast algorithm called Most Request Served (MRS) and its variants with caching strategies for on-time delivery of data in Real-Time Information Dispatch System. This family of algorithms consider request deadline, data object size and data popularity in making scheduling decisions. Although previous scheduling algorithms also base on some or all of these attributes to choose the most beneficial data to be broadcast, they did not consider the loss brought by their scheduling decisions. However, MRS considers both gain and loss in making a scheduling decision. We have performed a series of simulation experiments to compare the performance of various algorithms. Simulation results show that our proposed broadcast algorithm not only succeeds in providing good on-time delivery of data but at the same time provides 20% of improvement in response time over traditional scheduling algorithms like First-In-First-Out (FIFO) and Earliest-Deadline-First (EDF). Simulation results also show that our proposed caching strategy provides further improvement in terms of percentage of requests finished in time over traditional caching strategy like Least Recently Used (LRU).

Toward Broadcast Reliability in Mobile Ad Hoc Networks with Double Coverage

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 objective of reducing broadcast redundancy while still providing high delivery ratio under high transmission error rate is a major challenge in MANETs. In this paper, we propose a simple broadcast algorithm, called double-covered broadcast (DCB), which takes advantage of broadcast redundancy to improve the delivery ratio in an environment that has rather high transmission error rate. Among the 1-hop neighbors of the sender, only selected forwarding nodes retransmit the broadcast message. Forwarding nodes are selected in such a way that 1) the sender's 2-hop neighbors are covered and 2) the sender's 1-hop neighbors are either forwarding nodes or nonforwarding nodes covered by at least two forwarding neighbors. The retransmissions of the forwarding nodes are received by the sender as the confirmation of their reception of the packet. The nonforwarding 1-hop neighbors of the sender do not acknowledge the reception of the broadcast. If the sender does not detect all its forwarding nodes' retransmissions, it resends the packet until the maximum number of retries is reached. Simulation results show that the proposed broadcast algorithm provides good performance under a high transmission error rate environment