Dynamic traffic congestion pricing and electric vehicle charging management system for the internet of vehicles in smart cities

The integration of the Internet of Vehicles(IoV)in future smart cities could help solve many traffic-related challenges,such as reducing traffic congestion and traffic accidents.Various congestion pricing and electric vehicle charging policies have been introduced in recent years.Nonetheless,the majority of these schemes emphasize penalizing the vehicles that opt to take the congested roads or charge in the crowded charging station and do not reward the vehicles that cooperate with the traffic management system.In this paper,we propose a novel dynamic traffic congestion pricing and electric vehicle charging management system for the internet of vehicles in an urban smart city environment.The proposed system rewards the drivers that opt to take alternative congested-free ways and congested-free charging stations.We propose a token management system that serves as a virtual currency,where the vehicles earn these tokens if they take alternative non-congested ways and charging stations and use the tokens to pay for the charging fees.The proposed system is designed for Vehicular Ad-hoc Networks(VANETs)in the context of a smart city environment without the need to set up any expensive toll collection stations.Through large-scale traffic simulation in different smart city scenarios,it is proved that the system can reduce the traffic congestion and the total charging time at the charging stations.

Incentive-Driven Approach for Misbehavior Avoidance in Vehicular Networks

For efficient and robust information exchange in the vehicular adhoc network,a secure and trusted incentive reward is needed to avoid and reduce the intensity of misbehaving nodes and congestion especially in the case where the periodic beacons exploit the channel.In addition,we cannot be sure that all vehicular nodes eagerly share their communication assets to the system for message dissemination without any rewards.Unfortunately,there may be some misbehaving nodes and due to their selfish and greedy approach,these nodes may not help others on the network.To deal with this challenge,trust-based misbehavior avoidance schemes are generally reflected as the capable resolution.In this paper,we employed a fair incentive mechanism for cooperation aware vehicular communication systems.In order to deploy a comprehensive credit based rewarding scheme,the proposed rewardbased scheme fully depends on secure and reliable cryptographic procedures.In order to achieve the security goals,we used the cryptographic scheme to generate a certified public key for the authenticity of every message exchange over the network.We evaluated the friction of misbehaving vehicles and the effect of rewarding schemes in context with honest messages dissemination over the network.

Load Balancing Routing Algorithm Based on Extended Link States in LEO Constellation Network

As an important part of satellite communication network,LEO satellite constellation network is one of the hot research directions.Since the nonuniform distribution of terrestrial services may cause inter-satellite link congestion,improving network load balancing performance has become one of the key issues that need to be solved for routing algorithms in LEO network.Therefore,by expanding the range of available paths and combining the congestion avoidance mechanism,a load balancing routing algorithm based on extended link states in LEO constellation network is proposed.Simulation results show that the algorithm achieves a balanced distribution of traffic load,reduces link congestion and packet loss rate,and improves throughput of LEO satellite network.

Explicit Rate Based Transmission Control Scheme in Vehicle-to-lnfrastructure Communication Networks

In Vehicle-to-infrastructure(V2I)communication networks,mobile users are able to access Internet services,such as video streaming,digital map downloading,database access,online gaming,and even safety services like accident alarm,traffic condition broadcast,etc.,through fixed roadside units.However,the dynamics of communication environment and frequent changing topology critically challenge the design of an efficient transport layer protocol,which makes it difficult to guarantee diverse Quality of Service(QoS) requirements for various applications.In this paper,we present a novel transport layer scheme in infrastructure based vehicular networks,and aim to resolve some challenging issues such as source transfer rate adjustment,congestion avoidance,and fairness.By precisely detecting packet losses and identifying various causes of these losses(for example,link disconnection,channel error,packet collision,buffer overflow),the proposed scheme adopts different reacting mechanisms to deal with each of the losses.Moreover,it timely monitors the buffer size of the bottleneck Road-Side Unit(RSU),and dynamically makes transfer rate feedbacks to source nodes to avoid buffer overflow or vacancy.Finally,analysis and simulation results show that the proposed scheme not only successfully reduces packet losses because of buffer overflow and link disconnection but also improves the utilization efficiency of channel resource.

Scheduling Scheme for Cellular-Based Machine-Type Communication

Cellular-based Machine-Type Communication (MTC) will become more and more important in the near future for the advantage of the long-distance wireless communication.However,a large number of MTC applications introduce heavy load to cellular network.MTC traffic scheduling schemes are proposed to avoid congestion in this paper.Our approaches are based on the delay-tolerance of MTC traffic.Some MTC traffic is postponed until the network load becomes light.Moreover,our scheme efficiently utilizes the bandwidth resources reserved for handover in traditional cellular network.Simulation results show that the utility usage of radio resources is improved and the congestion probability is reduced.

End-to-End Rate Adaptation to Support Heterogeneous Services for Infrastructure-Based Vehicular Networks

Vehicle to Infrastructure （V2I） communications aim to provide mobile users on the road low-cost Internet and driver safety services. However, to meet Quality of Service （QoS） requirements of various applications and officiently utilize limited wireless channel resourc- es, the transport layer protocol has to perform effective rate control in low channel quality and frequent changing topology communica- tion environment. In this paper, we propose a novel rate-control scheme in infrastructure based vehicular networks that avoids conges- tion and starvation and promotes fairness in end-to-end V2I communications. In vehicular networks, a bottleneck roadside unit （RSU） keeps track of its buffer size, aggregate incoming rate, and link throughput, and appropriately allocates bandwidth to traversing flows. With feedback information from the RSU, source nodes dynamically adjust their sending rates to avoid buffer overflow or starvation at the bottleneck RSU. Simulation results show that the proposed scheme can reduce not only packet losses owing to buffer overflow but also buffer starvation time, which improves the utilization efficiency of wireless channel resource.

Achieving high throughput and TCP Reno fairness in delay-based TCP over large networks

The transport control protocol （TCP） has been widely used in wired and wireless Intemet applications such as FTP, email and HTTP. Numerous congestion avoidance algorithms have been proposed to improve the performance of TCP in various scenarios, especially for high speed and wireless networks. Although different algorithms may achieve different performance improvements under different network conditions, designing a congestion algorithm that can perform well across a wide spectrum of network conditions remains a great challenge. Delay-based TCP has a potential to overcome above challenges. However, the unfairness problem of delay-based TCP with TCP Reno blocks widely the deployment of delay-based TCP over wide area networks. In this paper, we proposed a novel delay-based congestion control algorithm, named FAST-FIT, which could perform gracefully in both ultra high speed networks and wide area networks, as well as keep graceful faimess with widely deployed TCP Reno hosts. FAST-FIT uses queuing delay as a primary input for controlling TCP congestion window. Packet loss is used as a secondary signal to adaptively adjust parameters of primary control process. Theoretical analysis and experimental results show that the performance of the algorithm is significantly improved as compared to other state-of-the-art algorithms, while maintaining good faimess.

S-Mesh: a Mesh-based on-chip network with separation of control and transmission

The current network-on-chip （NoC） topology cannot predict subsequent switch node status promptly. Switch nodes have to perform various functions such as routing decision, data forwarding, packet buffering, congestion control and properties of an NoC system. Therefore, these make switch architecture far more complex. This article puts forward a separating on-chip network architecture based on Mesh （S-Mesh）, S-Mesh is an on-chip network that separates routing decision flow from the switches. It consists of two types of networks： datapath network （DN） and control network （CN）. The CN establishes data paths for data transferring in DN. Meanwhile, the CN also transfers instructions between different resources. This property makes switch architecture simple, and eliminates conflicts in network interface units between the resource and switch. Compared with 2D-Mesh, Toms Mesh, Fat-tree and Butterfly, the average packet latency in S-Mesh is the shortest when the packet length is more than 53 B. Compared with 2D-Mesh, the areas savings of S-Mesh is about 3%-7/% and the power dissipation is decreased by approximate 2%.