Resource-Cardinality Based Scheme to Reduce Resource Lookup Cost in Structured P2P Networks

A P2P (peer-to-peer) network is a distributed system dependent on the IP-based networks, where independent nodes join and leave the network at their drive. The files (resource) are shared in distributed manner and each participating node ought to share its resources. Some files in P2P networks are accessed frequently by many users and such files are called popular files. Replication of popular files at different nodes in structured P2P networks provides significant reduction in resource lookup cost. Most of the schemes for resource access in the structured P2P networks are governed by DHT (Distributed Hash Table) or DHT-based protocols like Chord. Chord protocol is well accepted protocol among structured P2P networks due to its simple notion and robust characteristics. But Chord or other resource access protocols in structured P2P networks do not consider the cardinality of replicated files to enhance the lookup performance of replicated files. In this paper, we have exploited the cardinality of the replicated files and proposed a resource cardinality-based scheme to enhance the resource lookup performance in the structured P2P networks. We have also proposed the notion of trustworthiness factor to judge the reliability of a donor node. The analytical modelling and simulation analysis indicate that the proposed scheme performs better than the existing Chord and PCache protocols.

     

Practical Routing in Delay-Tolerant Networks

Delay-tolerant networks (DTNs) have the potential to interconnect devices in regions that current networking technology cannot reach. To realize the DTN vision, routes must be found over multiple unreliable, intermittently-connected hops. In this paper we present a practical routing protocol that uses only observed information about the network. We designed a metric that estimates the average waiting time for each potential next hop. This learned topology information is distributed using a link-state routing protocol, where the link-state packets are "flooded" using epidemic routing. The routing is recomputed each time connections are established, allowing messages to take advantage of unpredictable contacts. A message is forwarded if the topology suggests that the connected node is "closer" to the destination than the current node. We demonstrate through simulation that our protocol provides performance similar to that of schemes that have global knowledge of the network topology, yet without requiring that knowledge. Further, it requires significantly less resources than the alternative, epidemic routing, suggesting that our approach scales better with the number of messages in the network. This performance is achieved with minimal protocol overhead for networks of approximately 100 nodes.     

Distributed resource allocation for DS-CDMA-based multimedia ad hocwireless LANs

Power control in direct sequence code division multiple access (DS-CDMA) systems and power/rate allocation in multirate DS-CDMA based networks is an open and interesting research area which has attracted much attention. However, with a few exceptions, most researchers have emphasized centralized resource allocation algorithms for cellular systems where the base station keeps track of the requirements of the various users and is thus responsible for the management of network resources. Ad hoc wireless local area networks (WLANs), on the other hand, are generally configured as peer-to-peer networks with no centralized hub or controller. Thus resource allocation has to be conducted in a distributed fashion. We address the issue of distributed resource management for multirate DS-CDMA based multimedia WLANs by (1) presenting a distributed resource allocation protocol, known as distributed resource negotiation protocol (DRNP) that builds on the RTS/CTS bandwidth reservation mechanism provided by IEEE 802.111, and provides quality of service (QoS) guarantees through distributed control of resources in DS-CDMA based multimedia WLANs and (2) investigating the performance of various resource allocation schemes within the context of DRNP, in terms of network wide metrics such as overall throughput and blocking rates     

An agent-based incentive mechanism for P2P systems

1 Introduction P2P systems differ from the traditional distributed computing systems. They are self-organizing, distributed resource-sharing networks. In P2P systems, there is no central authority that controls or manages the various components. Nodes can…     

Provably Secure On-Demand Source Routing in Mobile Ad Hoc Networks

Routing is one of the most basic networking functions in mobile ad hoc networks. Hence, an adversary can easily paralyze the operation of the network by attacking the routing protocol. This has been realized by many researchers and several "secure" routing protocols have been proposed for ad hoc networks. However, the security of those protocols has mainly been analyzed by informal means only. In this paper, we argue that flaws in ad hoc routing protocols can be very subtle, and we advocate a more systematic way of analysis. We propose a mathematical framework in which security can be precisely defined and routing protocols for mobile ad hoc networks can be proved to be secure in a rigorous manner. Our framework is tailored for on-demand source routing protocols, but the general principles are applicable to other types of protocols too. Our approach is based on the simulation paradigm, which has already been used extensively for the analysis of key establishment protocols, but, to the best of our knowledge, it has not been applied in the context of ad hoc routing so far. We also propose a new on-demand source routing protocol, called endairA, and we demonstrate the use of our framework by proving that it is secure in our model     

The Emergence of Industrial Control Networks for Manufacturing Control, Diagnostics, and Safety Data

The most notable trend in manufacturing over the past five years is probably the move towards networks at all levels. At lower levels in the factory infrastructure, networks provide higher reliability, visibility, and diagnosability, and enable capabilities such as distributed control, diagnostics, safety, and device interoperability. At higher levels, networks can leverage internet services to enable factory-wide automated scheduling, control, and diagnostics; improve data storage and visibility; and open the door to e-manufacturing. This paper explores current trends in the use of networks for distributed, multilevel control, diagnostics, and safety. Network performance characteristics such as delay, delay variability, and determinism are evaluated in the context of networked control applications. This paper also discusses future networking trends in each of these categories and describes the actual application of all three categories of networks on a reconfigurable factory testbed (RFT) at the University of Michigan. Control, diagnostics, and safety systems are all enabled in the RFT utilizing multitier networked technology including DeviceNet, PROFIBUS, OPC, wired and wireless Ethernet, and SafetyBUS p. This paper concludes with a discussion of trends in industrial networking, including the move to wireless for all categories, and the issues that must be addressed to realize these trends     

Location-Aware Services over Vehicular Ad-Hoc Networks using Car-to-Car Communication

Recent advances in wireless inter-vehicle communication systems enable the establishment of vehicular ad-hoc networks (VANET) and create significant opportunities for the deployment of a wide variety of applications and services to vehicles. In this work, we investigate the problem of developing services that can provide car drivers with time-sensitive information about traffic conditions and roadside facilities. We introduce the vehicular information transfer protocol (VITP), a location- aware, application-layer, communication protocol designed to support a distributed service infrastructure over vehicular ad- hoc networks. We describe the key design concepts of the VITP protocol and infrastructure. We provide an extensive simulation study of VITP performance on large-scale vehicular networks under realistic highway and city traffic conditions. Our results demonstrate the viability and effectiveness of VITP in providing location-aware services over VANETs.     

Enforcing Cooperative Resource Sharing in Untrusted P2P Computing Environments

Peer-to-Peer (P2P) computing is widely recognized as a promising paradigm for building next generation distributed applications. However, the autonomous, heterogeneous, and decentralized nature of participating peers introduces the following challenge for resource sharing: how to make peers profitable in the untrusted P2P environment? To address the problem, we present a self-policing and distributed approach by combining two models: PET, a personalized trust model, and M-CUBE, a multiple-currency based economic model, to lay a foundation for resource sharing in untrusted P2P computing environments. PET is a flexible trust model that can adapt to different requirements, and provides the solid support for the currency management in M-CUBE. M-CUBE provides a novel self-policing and quality-aware framework for the sharing of multiple resources, including both homogeneous and heterogeneous resources. We evaluate the efficacy and performance of this approach in the context of a real application, a peer-to-peer Web server sharing. Our results show that our approach is flexible enough to adapt to different situations and effective to make the system profitable, especially for systems with large scale.     

PACMAN: passive autoconfiguration for mobile ad hoc networks

Mobile ad hoc networks (MANETs) enable the communication between mobile nodes via multihop wireless routes without depending on a communication infrastructure. In contrast to infrastructure-based networks, MANET's support autonomous and spontaneous networking and, thus, should be capable of self-organization and -configuration. This paper presents passive autoconfiguration for mobile ad hoc network (PACMAN), a novel approach for the efficient distributed address autoconfiguration of mobile ad hoc networks. Special features of PACMAN are the support for frequent network partitioning and merging, and very low protocol overhead. This is accomplished by using cross-layer information derived from ongoing routing protocol traffic, e.g., address conflicts are detected in a passive manner based on anomalies in routing protocol traffic. Furthermore, PACMAN assigns Internet protocol (IP) addresses in a way that enables their compression, which can significantly reduce the routing protocol overhead. The performance of PACMAN is analyzed in detail based on various simulation results.     

Accelerating peer-to-peer networks for video streaming using multipoint-to-point communication

Existing transport layer protocols such as TCP and UDP are designed specifically for point-to-point communication. The increased popularity of peer-to-peer networking has brought changes in the Internet that provided users with potentially multiple replicated sources for content retrieval. However, applications that leverage such parallelism have thus far been limited to non-real-time file downloads. In this article we consider the problem of multipoint-to-point video streaming over peer-to-peer networks. We present a transport layer protocol called R/sup 2/CP that effectively enables real-time multipoint-to-point video streaming. R/sup 2/CP is a receiver-driven multistate transport protocol. It requires no coordination between multiple sources, accommodates flexible application layer reliability semantics, uses TCP-friendly congestion control, and delivers to the video stream the aggregate of the bandwidths available on the individual paths. Simulation results show great performance benefits using R/sup 2/CP in peer-to-peer networks.     

Packet sequencing: a deterministic protocol for QoS in IP networks

We describe a deterministic protocol for routing delay and loss-sensitive traffic through an IP network. Unlike traditional approaches, the method described here - packet sequencing - does not rely on queue management. Instead, it uses a temporally-based deterministic protocol to coordinate and switch IP packets on a systemwide basis. As a result, end-to-end throughput is guaranteed, without packet loss, loss variance, or accumulated performance impairment; additionally, end-to-end delay is minimized, and jitter is essentially eliminated. We also show that packet sequencing can complement conventional IP networks: sequencing does not negate the use of queue management QoS methods that are the subject of considerable ongoing study. This article describes the fundamental approach, issues associated with scalability, illustrative performance in the context of storage networking, and attributes related to the security and reliability of IP networks.     

Cognitive Radio and Networking Research at Virginia Tech

More than a dozen Wireless @ Virginia Tech faculty are working to address the broad research agenda of cognitive radio and cognitive networks. Our core research team spans the protocol stack from radio and reconfigurable hardware to communications theory to the networking layer. Our work includes new analysis methods and the development of new software architectures and applications, in addition to work on the core concepts and architectures underlying cognitive radios and cognitive networks. This paper describes these contributions and points towards critical future work that remains to fulfill the promise of cognitive radio. We briefly describe the history of work on cognitive radios and networks at Virginia Tech and then discuss our contributions to the core cognitive processing underlying these systems, focusing on our cognitive engine. We also describe developments that support the cognitive engine and advances in radio technology that provide the flexibility desired in a cognitive radio node. We consider securing and verifying cognitive systems and examine the challenges of expanding the cognitive paradigm up the protocol stack to optimize end-to-end network performance. Lastly, we consider the analysis of cognitive systems using game theory and the application of cognitive techniques to problems in dynamic spectrum sharing and control of multiple-input multiple-output radios.     

A scheme for high-performance LAN interconnection across publicMAN's

The proliferation of local area networks (LANs) and the emergence of high-bandwidth public networks will create an environment in which it will become increasingly simple and attractive to communicate among different organizations across a common public networking infrastructure. The open bridging scheme proposed, which employs inherent features of forthcoming cell-based metropolitan area networks (MANs) in order to achieve efficient interenterprise communications is introduced. It uses enhanced remote LAN bridging techniques to ensure router-level functionality with bridge-level simplicity and performance. The practicality of open bridging is shown by describing how it can be incorporated in networks using current standard protocol stacks, such as open systems interconnnection (OSI) and transmission control protocol/internet protocol (TCP/IP)     

Extending P2PMesh: topology‐aware schemes for efficient peer‐to‐peer data sharing in wireless mesh networks

Wireless mesh networks (WMNs) have emerged as a promising technology that provides low‐cost broadband access to the Internet for fixed and mobile wireless end users. An orthogonal evolution in computer networking has been the rise of peer‐to‐peer (P2P) applications such as P2P data sharing. It is of interest to enable effective P2P data sharing in this type of networks. Conventional P2P data sharing systems are not cognizant of the underlying network topology and therefore suffer from inefficiency. We argue for dual‐layer mesh network architecture with support from wireless mesh routers for P2P applications. The main contribution of this paper is P2PMesh: a topology‐aware system that provides combined architecture and efficient schemes for enabling efficient P2P data sharing in WMNs. The P2PMesh architecture utilizes three schemes: (i) an efficient content lookup that mitigates traffic load imbalance at mesh routers; (ii) an efficient establishment of download paths; and (iii) a data transfer protocol for multi‐hop wireless networks with limited capacity. We note here that the path establishment and data transfer schemes are specific to P2P traffic and that other traffic would use routes determined by the default routing protocol in the WMN. Simulation results suggest that P2PMesh has the potential to improve the performance of P2P applications in a wireless multi‐hop setting; specifically, we focused on data sharing, but other P2P applications can also be supported by this approach. Copyright © 2011 John Wiley & Sons, Ltd.     

Distributed Nonlinear Integer Optimization for Data-Optical Internetworking

We present a novel approach for joint optical network provisioning and Internet protocol (IP) traffic engineering, in which the IP and optical networks collaboratively optimize a combined objective of network performance and lightpath provisioning cost. We develop a framework for distributed multilayer optimization. Our framework is built upon the IP-over-optical (IPO) overlay model, where each network domain has a limited view of the other. Our formulation allows the two domains to communicate and coordinate their decisions through minimal information exchange. Our solution is based on a novel application of Generalized Bender's Decomposition, which divides a difficult global optimization problem into tractable subproblems, each solved by a different domain. The procedure is iterative and converges to the global optimum. We present case studies to demonstrate the efficiency and applicability of our approach in various networking scenarios. Our work builds a foundation for “multilayer” grooming, which extends traditional grooming in the optical domain to include data networks. The data networks are active participants in the grooming process with intelligent homing of data traffic to optical gateways.     

A case for end system multicast

The conventional wisdom has been that Internet protocol (IP) is the natural protocol layer for implementing multicast related functionality. However, more than a decade after its initial proposal, IP multicast is still plagued with concerns pertaining to scalability, network management, deployment, and support for higher layer functionality such as error, flow, and congestion control. We explore an alternative architecture that we term end system multicast, where end systems implement all multicast related functionality including membership management and packet replication. This shifting of multicast support from routers to end systems has the potential to address most problems associated with IP multicast. However, the key concern is the performance penalty associated with such a model. In particular, end system multicast introduces duplicate packets on physical links and incurs larger end-to-end delays than IP multicast. We study these performance concerns in the context of the Narada protocol. In Narada, end systems self-organize into an overlay structure using a fully distributed protocol. Further, end systems attempt to optimize the efficiency of the overlay by adapting to network dynamics and by considering application level performance. We present details of Narada and evaluate it using both simulation and Internet experiments. Our results indicate that the performance penalties are low both from the application and the network perspectives. We believe the potential benefits of transferring multicast functionality from end systems to routers significantly outweigh the performance penalty incurred.     

Time-sensitive software-defined networking (Ts-SDN) control architecture for flexi-grid optical networks with data center application

Data center interconnected by flexi-grid optical networks is a promising scenario to meet the high burstiness and high bandwidth requirement of data center application, because flexi-grid optical networks can allocate spectral resources for applications in a dynamic, tunable and efficient control manner. Meanwhile, as centralized control architecture, the software-defined networking (SDN) enabled by OpenFlow protocol can provide maximum flexibility for the networks and make a unified control over various resources for the joint optimization of data center and network resources. Time factor is firstly introduced into SDN-based control architecture for flexi-grid optical networks supporting data center application. A traffic model considering time factor is proposed, and a requirement parameter, i.e., bandwidth-period product is adopted for the service requirement measurement. Then, time-sensitive software-defined networking (Ts-SDN)-based control architecture is designed with OpenFlow protocol extension. A novel deadline-driven PCE algorithm is proposed for the deadline-driven service under Ts-SDN-based control architecture, which can complete data center selection, path computation and bandwidth resource allocation. Finally, simulation results shows that our proposed Ts-SDN control architecture and deadline-driven PCE algorithm can improve the application and network performance to a large extent in blocking probability.     

A New Access Control Solution for a Multi-Provider Wireless Environment

The fundamental goal in future 4G mobile multi-service networks is to provide an efficient mobile computing environment. We presume that future terminals will be equipped with multiple heterogeneous wireless interfaces. We want to enable each user to seamlessly move between different providers networks. Besides seamless roaming, a key consideration is also devoted to quality-of-service provision. In this article, we propose a model and an architectural framework for supporting quality of service in the context of interconnected multi-provider wireless systems. The proposed integrated COPS-based management and RADIUS-based access control architecture will allow providers to offer multimedia services while optimizing the use of the underlying network resources. We suggest new concepts and protocols to provide solutions to these challenges and describe the French national research project named MMQoS aiming on building such future networks.     

Call admission control in mobile cellular networks: a comprehensive survey

Call admission control (CAC) is a key element in the provision of guaranteed quality of service (QoS) in wireless networks. The design of CAC algorithms for mobile cellular networks is especially challenging given the limited and highly variable resources, and the mobility of users encountered in such networks. This article provides a survey of admission control schemes for cellular networks and the research in this area. Our goal is to provide a broad classification and thorough discussion of existing CAC schemes. We classify these schemes based on factors such as deterministic/stochastic guarantees, distributed/local control and adaptivity to traffic conditions. In addition to this, we present some modeling and analysis basics to help in better understanding the performance and efficiency of admission control schemes in cellular networks. We describe several admission control schemes and compare them in terms of performance and complexity. Handoff prioritization is the common characteristic of these schemes. We survey different approaches proposed for achieving handoff prioritization with a focus on reservation schemes. Moreover, optimal and near‐optimal reservation schemes are presented and discussed. Also, we overview other important schemes such as those designed for multi‐service networks and hierarchical systems as well as complete knowledge schemes and those using pricing for CAC. Finally, the paper concludes on the state of current research and points out some of the key issues that need to be addressed in the context of CAC for future cellular networks. Copyright © 2005 John Wiley & Sons, Ltd.