DAWN: A Density Adaptive Routing for Deadline-Based Data Collection in Vehicular Delay Tolerant Networks

Vehicular Delay Tolerant Networks （DTN） use moving vehicles to sample and relay sensory data for urban areas, making it a promising low-cost solution for the urban sensing and infotainment applications. However, routing in the DTN in real vehicle fleet is a great challenge due to uneven and fluctuant node density caused by vehicle mobility patterns. Moreover, the high vehicle density in urban areas makes the wireless channel capacity an impactful factor to network performance. In this paper, we propose a local capacity constrained density adaptive routing algorithm for large scale vehicular DTN in urban areas which targets to increase the packet delivery ratio within deadline, namely Density Adaptive routing With Node deadline awareness （DAWN）. DAWN enables the mobile nodes awareness of their neighbor density, to which the nodes＇ transmission manners are adapted so as to better utilize the limited capacity and increase the data delivery probability within delay constraint based only on local information. Through simulations on Manhattan Grid Mobility Model and the real GPS traces of 4960 taxi cabs for 30 days in the Beijing city, DAWN is demonstrated to outperform other classical DTN routing schemes in performance of delivery ratio and coverage within delay constraint. These simulations suggest that DAWN is practically useful for the vehicular DTN in urban areas.

Adaptive Multi-Cost Routing Protocol to Enhance Lifetime for Wireless Body Area Network

Wireless Body Area Network(WBAN)technologies are emerging with extensive applications in several domains.Health is a fascinating domain of WBAN for smart monitoring of a patient’s condition.An important factor to consider in WBAN is a node’s lifetime.Improving the lifetime of nodes is critical to address many issues,such as utility and reliability.Existing routing protocols have addressed the energy conservation problem but considered only a few parameters,thus affecting their performance.Moreover,most of the existing schemes did not consider traffic prioritization which is critical in WBANs.In this paper,an adaptive multi-cost routing protocol is proposed with a multi-objective cost function considering minimum distance from sink,temperature of sensor nodes,priority of sensed data,and maximum residual energy on sensor nodes.The performance of the proposed protocol is compared with the existing schemes for the parameters:network lifetime,stability period,throughput,energy consumption,and path loss.It is evident from the obtained results that the proposed protocol improves network lifetime and stability period by 30%and 15%,respectively,as well as outperforms the existing protocols in terms of throughput,energy consumption,and path loss.

Adaptive Route Sink Relocation Using Cluster Head Chain Cycling Model in WSN

Wireless Sensor Networks(WSN)have revolutionized the processes involved in industrial communication.However,the most important challenge faced by WSN sensors is the presence of limited energy.Multiple research inves-tigations have been conducted so far on how to prolong the energy in WSN.This phenomenon is a result of inability of the network to have battery powered-sensor terminal.Energy-efficient routing on packetflow is a parallel phenomenon to delay nature,whereas the primary energy gets wasted as a result of WSN holes.Energy holes are present in the vicinity of sink and it is an important efficient-routing protocol for WSNs.In order to solve the issues discussed above,an energy-efficient routing protocol is proposed in this study named as Adaptive Route Decision Sink Relocation Protocol using Cluster Head Chain Cycling approach(ARDSR-CHC2H).The proposed method aims at improved communica-tion at sink-inviting routes.At this point,Cluster Head Node(CHN)is selected,since it consumes low energy and permits one node to communicate with others in two groups.The main purpose of the proposed model is to reduce energy con-sumption and define new interchange technology.A comparison of simulation results demonstrates that the proposed algorithm achieved low cluster creation time,better network error and high Packet Delivery Rate with less network failure.

PERFORMANCE ANALYSIS OF MINIMAL PATH FAULT TOLERANT ROUTING IN NOC

Occurrence of faults in Network on Chip(NoC) is inevitable as the feature size is con-tinuously decreasing and processing elements are increasing in numbers.Faults can be revocable if it is transient.Transient fault may occur inside router,or in the core or in communication wires.Examples of transient faults are overflow of buffers in router,clock skew,cross talk,etc..Revocation of transient faults can be done by retransmission of faulty packets using oblivious or adaptive routing algorithms.Irrevocable faults causes non-functionality of segment and mainly occurs during fabrication process.NoC reliability increases with the efficient routing algorithms,which can handle the maximum faults without deadlock in network.As transient faults are temporary and can be easily revoked using re-transmission of packet,permanent faults require efficient routing to route the packet by bypassing the nonfunctional segments.Thus,our focus is on the analysis of adaptive minimal path fault tolerant routing to handle the permanent faults.Comparative analysis between partial adaptive fault tolerance routing West-First,North-Last,Negative-First,Odd Even,and Minimal path Fault Tolerant routing(MinFT) algorithms with the nodes and links failure is performed using NoC Interconnect RoutinG and Application Modeling simulator(NIRGAM) for the 2D Mesh topology.Result suggests that MinFT ensures data transmission under worst conditions as compared to other adaptive routing algorithms.

Energy Efficient On-Chip Communications Implementation Based on Power Slacks

The quest for energy efficiency has growing importance in high performance many-core systems. However, in current practices, the power slacks, which are the differences observed between the input power budget and the actual power consumed in the many-core systems, are typically ignored, thus leading to poor energy efficiency. In this paper, we propose a scheme to effectively power the on-chip communications by exploiting the available power slack that is totally wasted in current many-core systems. As so, the demand for extra energy from external power sources （e.g., batteries） is minimized, which helps improve the overall energy efficiency. In essence, the power slack is stored at each node and the proposed routing algorithm uses a dynamic programming network to find the globally optimal path, along which the total energy stored on the nodes is the maximum. Experimental results have confirmed that the proposed scheme, with low hardware overhead, can reduce latency and extra energy consumption by 44% and 48%, respectively, compared with the two competing routing methods.

A survey of routing algorithm for mesh Network-on-Chip

With the rapid development of semiconductor in- dustry, the number of cores integrated on chip increases quickly, which brings tough challenges such as bandwidth, scalability and power into on-chip interconnection. Under such background, Network-on-Chip （NoC） is proposed and gradually replacing the traditional on-chip interconnections such as sharing bus and crossbar. For the convenience of physical layout, mesh is the most used topology in NoC design. Routing algorithm, which decides the paths of pack- ets, has significant impact on the latency and throughput of network. Thus routing algorithm plays a vital role in a wellperformed network. This study mainly ：focuses on the routing algorithms of mesh NoC. By whether taking network information into consideration in routing decision, routing algorithms of NoC can be roughly classified into oblivious routing and adaptive routing. Oblivious routing costs less without adaptiveness while adaptive routing is on the contrary. To combine the advantages of oblivious and adaptive routing algorithm, half-adaptive algorithms were proposed. In this paper, the concepts, taxonomy and features of routing algorithms of NoC are introduced. Then the importance of routing algorithms in mesh NoC is highlighted, and representative routing algorithms with respective features are reviewed and summarized. Finally, we try to shed light upon the future work of NoC routing algorithms.

Heuristics of node selection criteria to assess robustness of world airport network

The world airport network（WAN） is one of the networked infrastructures that shape today＇s economic and social activity, so its resilience against incidents affecting the WAN is an important problem. In this paper, the robustness of air route networks is extended by defining and testing several heuristics to define selection criteria to detect the critical nodes of the WAN.In addition to heuristics based on genetic algorithms and simulated annealing, custom heuristics based on node damage and node betweenness are defined. The most effective heuristic is a multiattack heuristic combining both custom heuristics. Results obtained are of importance not only for advance in the understanding of the structure of complex networks, but also for critical node detection.