Abstract

This paper addresses the issue of pricing-based distributed resource allocation via scheduling in a communication network. Introducing the temporal aspect in the resource allocation problem presents new challenges e.g. in accounting for the durations and deadlines of the resource requests. Dynamic real-time pricing concepts are discussed for the decentralized sharing of network resources. A numerical example illustrates the benefit of congestion based pricing in a dynamic communication network. The quality of service that results from decentralized resource allocation is studied from the point of view of a power-controlled wireless network. The model is based on a dynamic noncooperative game and is related to recent work on centrally optimal (Pareto-optimal) distributed dynamic resource allocation. Document type: Part of book or chapter of book

Abstract

Recent advances in wireless communication technologies are making it possible for automobiles to be integrated into the global network. Intelligent Transportation Systems with vehicles in the loop are expected to significantly improve road safety, reduce traffic congestion and cut greenhouse gas emissions. This is made possible in the USA by Dedicated Short Range Communications (DSRC), which employs the IEEE 802.11p standard over the 75MHz of spectrum in the 5.9 GHz band allocated by the FCC for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. DSRC is expected to revolutionize road transportation by making possible many real-time safety applications. However, global deployment of DSRC is not expected to materialize in the near term due to regulatory and financial challenges. In the meantime, vehicles and their passengers are increasingly equipped with different forms of wireless networking capabilities, e.g., cellular, WiFi and WiMAX. Thus there is also a growing interest in supporting applications like infotainment, travel advisory, route planning, etc., using heterogeneous wireless networks. In this presentation, I shall describe several applications that leverage the wireless communications to put vehicles in the loop. Different applicants impose different requirements on the wireless network for data routing, transfer latency, etc. I shall review the technical challenges that need to be overcome to meet some of these requirements, and describe solutions developed in our recent research to meet these challenges. I shall conclude the presentation by discussing some future research directions. Document type: Part of book or chapter of book

Abstract

In order to meet a tremendous amount of data storage requirement in next-generation wireless networks, an increasing number of cloud data centers has been deployed around the world. The underlying core networks are expected to provide the ability to store data in a dynamic and scalable computing environment. The traditional Internet Protocol (IP) has shown to be restricted due to its static architecture, which accordingly motivates the development of Software-Defined Networks (SDNs). In the SDNs, Traffic Engineering (TE) is simpler and programmable with a controller without the requirement of reconfiguration for all network devices. However, the existing TE algorithm of the SDNs rejects a number of requested flows caused by their undetermined routing paths where only flow bandwidth is considered in path determination. This paper proposes a Quality-of-Service (QoS) based Flow Assignment algorithm which enables the computation of end-to-end path for traffic flows guaranteeing the QoS requirements including bandwidth, end-to-end delay and packet loss probability. Through the Open Source Hybrid IP/SDNs platform, the proposed algorithm is validated and shown to significantly reduce flow rejection rate of up to 50% compared to the conventional approach, and therefore can be used to implement an effective DiffServ mechanism for flow allocation in the SDNs. Document type: Part of book or chapter of book

Abstract

International audience We introduce a continuous time stochastic broadcast calculus for mobile and wireless networks. The mobility between nodes in a network is modeled by a stochastic mobility function which allows to change part of a network topology depending on an exponentially distributed delay and a network topology constraint. We allow continuous time stochastic behavior of processes running at network nodes, e.g. in order to be able to model randomized protocols. The introduction of group broadcast and an operator to help avoid flooding allows us to define a novel notion of broadcast abstraction. Finally, we define a weak bisimulation congruence and apply our theory on a leader election protocol. Document type: Part of book or chapter of book

Abstract

We present a new approach for seamless congestion control over heterogeneous networks containing wired and wireless IEEE 802.11 links. The approach uses ECN (Explicit Congestion Notification) as a common signalling mechanism for conveying congestion information from both wired and wireless links. Two additional novel aspects of the approach are that ECN marking for a wireless link, due to the way resources are shared, is performed for both the uplink and the downlink based on measurements of the aggregate traffic in both directions, and the marking mechanism dynamically adapts to varying traffic and load conditions. Simulation results demonstrate that our approach achieves higher fairness compared to drop-tail queueing, and can effectively control the average packet delay over the wireless link. Document type: Part of book or chapter of book