A location‐based service advertisement algorithm for pervasive service discovery in wireless mobile networks

The practical success of pervasive services running in mobile wireless networks relies largely on its flexibility in providing adaptive and cost‐effective services. Service discovery is an essential mechanism to achieve this goal. As an enhancement to our previous work for service discovery, that is, model‐based service discovery (MBSD), this paper proposes a location‐based service advertisement (SA) algorithm named as MBSD‐sa. MBSD‐sa advocates the importance of service location to the service availability and integrates the service location information together with the service semantic information into service information for advertisement. MBSD‐sa utilizes prediction to estimate the service location so as to reduce the number of SA messages (SAMs). Two complementary types of SA mechanisms (Types 1 and 2) are employed by MBSD‐sa to strike the balance between the SAM overhead and the accuracy of service information. The performance of MBSD‐sa is analyzed both numerically and using simulations. Copyright © 2008 John Wiley & Sons, Ltd.     

An eigenvalue‐based edge infrastructure for cloud‐based CDN

In today's dynamic video landscape, an end user needs services to be delivered to any devices anytime with less delay over the Internet. Now users' expectation has changed; they want faster time‐to‐market, cost reduction, and the ability to adjust according to the evolving requirements, which are a limit for the traditional server‐based approach. The explosive growth of the internet multimedia application needs a new approach to content delivery to overcome the limitations of server‐based techniques. Cloud‐based content delivery networks (CCDNs) have recently started to emerge where contents are cached from the cloud storage and delivered through the distribution service to meet quality of services (QoS) of requested services. In this paper, we dealt with CCDN deployment problem and proposed a new eigenvalue‐based edge infrastructure for a network service provider to serve the users with a variation on proximity interest concerning operational cost and user QoS satisfaction. The edge infrastructure designing is a two‐step process: (a) ideal location search for placing edge server and (b) edge server placement and capacity provisioning. The performance of the proposed approach is appraised via modeling and simulation. Performance evaluation outcomes are exhibited to manifest the effectiveness and competitiveness of our approach when compared with existing algorithms.     

Proficient selection of gateway and base station by adroit algorithm in cloud‐VMesh network

Cloud computing is alluring for the vehicular mesh (VMesh) network. Cloud computing stipulates the computing resources and services on demand using the Internet. The VMesh network is a type of networking where each vehicle must not only capture and disseminate its own data but also serve as a gateway for another vehicle. The cloud‐VMesh network is a convergent technology encompassed of three key technologies, namely, vehicular mesh network, cloud computing, and networking. In this paper, we propose a new routing algorithm for cloud‐VMesh network, dubbed as adroit algorithm. The proposed adroit algorithm addresses the choosing of an optimal gateway and base station in the network layer from and to the service requesters and cloud server. The simulation study shows that the adroit algorithm augments the routing issues such as delay, packet loss, congestion and deployment cost in the cloud‐VMesh network, and it is justified based on the packet delivery ratio, average response time, routing overhead ratio, and packet collision ratio. The simulation results demonstrate that the adroit algorithm outperforms the existing protocols. Copyright © 2016 John Wiley & Sons, Ltd.     

FIPA‐based reference architecture for efficient discovery and selection of appropriate cloud service using cloud ontology

Cloud computing is considered the latest emerging computing paradigm and has brought revolutionary changes in computing technology. With the advancement in this field, the number of cloud users and service providers is increasing continuously with more diversified services. Consequently, the selection of appropriate cloud service has become a difficult task for a new cloud customer. In case of inappropriate selection of a cloud services, a cloud customer may face the vendor locked‐in issue and data portability and interoperability problems. These are the major obstacles in the adoption of cloud services. To avoid these complexities, a cloud customer needs to select an appropriate cloud service at the initial stage of the migration to the cloud. Many researches have been proposed to overcome the issues, but problems still exist in intercommunication standards among clouds and vendor locked‐in issues. This research proposed an IEEE multiagent Foundation for Intelligent Physical Agent (FIPA) compliance multiagent reference architecture for cloud discovery and selection using cloud ontology. The proposed approach will mitigate the prevailing vendor locked‐in issue and also alleviate the portability and interoperability problems in cloud computing. To evaluate the proposed reference architecture and compare it with the state‐of‐the‐art approaches, several experiments have been performed by utilizing the commonly used performance measures. Analysis indicates that the proposed approach enables significant improvements in cloud service discovery and selection in terms of search efficiency, execution, and response time.     

A reliable quality of service aware fault tolerant gateway discovery protocol for vehicular networks

A great interest in vehicular ad‐hoc networks has been noticed by the research community. General goals of vehicular networks are to enhance safety on the road and to ensure the convenience of passengers by continuously providing them, in real time, with information and entertainment options such as routes to destinations, traffic conditions, facilities' information, and multimedia/Internet access. Indeed, time efficient systems that have high connectivity and low bandwidth usage are most needed to cope with realistic traffic mobility conditions. One foundation of such a system is the design of an efficient gateway discovery protocol that guarantees robust connectivity between vehicles, while assuring Internet access. Little work has been performed on how to concurrently integrate load balancing, quality of service (QoS), and fault tolerant mechanisms into these protocols. In this paper, we propose a reliable QoS‐aware and location aided gateway discovery protocol for vehicular networks by the name of fault tolerant location‐based gateway advertisement and discovery. One of the features of this protocol is its ability to tolerate gateway routers and/or road vehicle failure. Moreover, this protocol takes into consideration the aspects of the QoS requirements specified by the gateway requesters; furthermore, the protocol insures load balancing on the gateways as well as on the routes between gateways and gateway clients. We discuss its implementation and report on its performance in contrast with similar protocols through extensive simulation experiments using the ns‐2 simulator. Copyright © 2013 John Wiley & Sons, Ltd.     

Integrated service discovery architecture for heterogeneous networks

The discovery and management of desired network services present significant challenges for mobile networks. Based on the Service Location Protocol, this paper proposes an integrated service discovery architecture for vehicular ad hoc networks. The proposed approach divides the network into several logical zones. The zone structure is formed virtually based on position information. Each logical zone may have a zone directory agent to manage registered services from service providers. The proposed architecture considers both vehicle‐to‐infrastructure and vehicle‐to‐vehicle communication modes and introduces roadside directory agents and vehicle directory agents to reduce deployment costs. We also introduce a substitute query technique, cache mechanism, and backup mechanism to improve the request hit ratio and reduce the message overhead of the substitute query. Finally, we implement the proposed mechanisms in Network Simulator version 2, with simulation results showing that the proposed architecture can provide a high average data hit ratio and low message overhead. Copyright © 2016 John Wiley & Sons, Ltd.     

车联网移动云系统虚拟机迁移技术研究

智能交通车联网的发展面临着异构网络传输容量瓶颈、海量信息高效处理瓶颈等一系列具有挑战性的难题。针对该系列问题,本文提出一种层次化移动云系统参考模型,使车载移动终端根据其网络环境与通信能力择优接入相应层次的云服务,达到移动网络资源与云计算资源的最佳匹配。同时,由于车载单元的快速移动性,车联网中的信息传输随时可能中断,这就制约了车联网业务服务质量的提高,对云计算持续稳定的服务构成了很大的挑战,这一瓶颈问题可以通过虚拟机动态迁移技术得到改善,从而实现服务的不间断。     

A management architecture for client‐defined cloud storage services

Cloud service providers offer virtual resources to users, who then pay for as much as they use. High‐speed networks help to overcome the limitation of geographical distances between clients and cloud servers, which encourage users to adopt cloud storage services for data backup and sharing. However, users use only a few cloud storage services because of the complexity of managing multiple accounts and distributing data to store. In this paper, we propose the client‐defined management architecture (CLIMA) that redefines a storage service by coordinating multiple cloud storage services from clients. We address practical issues of coordinating multiple cloud service providers using a client‐based approach. We implement a prototype as a realization of CLIMA, which achieves both reliability and privacy protection using erasure code and higher performance by optimally scheduling data transmission. We use our prototype to evaluate the benefits of CLIMA on commercial cloud storage service providers. Finally, CLIMA empowers clients to increase the manageability and flexibility of cloud storage services. Copyright © 2015 John Wiley & Sons, Ltd.     

VANET: A novel service for predicting and disseminating vehicle traffic information

The arrival of cloud computing technology promises innovative solutions to the problems inherent in existing vehicular ad hoc network (VANET) networks. Because of the highly dynamic nature of these networks in crowded conditions, some network performance improvements are needed to anticipate and disseminate reliable traffic information. Although several approaches have been proposed for the dissemination of data in the vehicular clouds, these approaches rely on the dissemination of data from conventional clouds to vehicles, or vice versa. However, anticipating and delivering data, in a proactive way, based on query message or an event driven has not been defined so far by these approaches. Therefore, in this paper, a VANET‐Cloud layer is proposed for traffic management and network performance improvements during congested conditions. For the traffic management, the proposed layer integrates the benefits of the connected sensor network (CSN) to collect traffic data and the cloud infrastructure to provide on‐demand and automatic cloud services. In this work, traffic services use a data exchange mechanism to propagate the predicted data using a fuzzy aggregation technique. In the evaluation phase, simulation results demonstrate the effectiveness of the proposed VANET‐Cloud layer to dramatically improve traffic safety and network performance as compared with recent works.     

SOS: Self‐organized secure framework for VANET

While authentication is a necessary requirement to provide security in vehicular ad hoc networks, user's personal information such as identity and location must be kept private. The reliance on road side units or centralized trusted authority nodes to provide security services is critical because both are vulnerable, thus cannot be accessed by all users, which mean security absence. In this paper, we introduce a self‐organized secure framework, deployed in vehicular ad hoc networks. The proposed framework solution is designed not only to provide an effective, integrated security and privacy‐preserving mechanism but also to retain the availability of all security services even if there are no road side units at all and/or the trusted authority node is compromised. A decentralized tier‐based security framework that depends on both trusted authority and some fully trusted nodes cooperated to distribute security services is presented. Our approach combines the useful features of both Shamir secret sharing with a trust‐based technique to ensure continuity of achieving all security services. Mathematical analysis of security issues that the proposed framework achieves as well as the availability of offering security services is provided. Proposed framework examination was done to show the performance in terms of storage, computation complexity, and communication overhead as well as its resilience against various types of attacks. Comparisons with different types of security schemes showed that the protocol developed gave better results in most comparison parameters while being unique ensuring continuity of security services delivery.     

Intent‐based service management for heterogeneous software‐defined infrastructure domains

One of the main challenges in delivering end‐to‐end service chains across multiple software‐defined networking (SDN) and network function virtualization (NFV) domains is to achieve unified management and orchestration functions. A very critical aspect is the definition of an open, vendor‐agnostic, and interoperable northbound interface (NBI) that should be as abstract as possible and decoupled from domain‐specific data and control plane technologies. In this paper, we propose a reference architecture and an intent‐based NBI for end‐to‐end service management across multiple technological domains. The general approach is tested in a heterogeneous OpenFlow/Internet‐of‐Things (IoT) SDN test bed, where the proposed solution is applied to a rather complex service provisioning scenario spanning three different technological domains: an IoT infrastructure deployment, a cloud‐based data collection, processing, and publishing platform, and a transport domain over a geographic network interconnecting the IoT domain and the data center hosting the cloud services.     

Lagrangean relaxation for service location in large‐scale networks with QoS constraints

Current trends in computing indicate that there is a great potential for service‐oriented computing and similar technologies, such as application‐oriented networks (AONs), where services can relocate to adapt to the conditions of the underlying network. In such environments, providing and consuming services and establishing a relationship between consumers (users of services) and producers (providers of services) are still challenging and vastly researched aspects. Bearing this in mind, we define a service location and planning (SLP) problem that uniquely matches producers to consumers and accounts for realistic parameters such as, quality of service (QoS) constraints of throughput and delay, and network constraints of underlying link layer bandwidth capacities, and cost of meeting consumer requests. Our contribution lies in the mathematical formulation of the SLP problem as an integer linear programming (ILP) problem that can be solved optimally for small‐scale networks and extending this work using Lagrangean relaxation (LR) approximation techniques to solve the SLP problem for large‐scale networks. Copyright © 2009 John Wiley & Sons, Ltd.     

Video‐on‐Demand (VoD) deployment over hospitality networks

Video‐on‐Demand (VoD) deployment over existing IP networks has recently gained significant popularity. Typically, the deployment of VoD is done in an arbitrary manner, without utilizing a proper engineering approach. In this paper, we present an engineering approach to deploy VoD services over IP‐based hospitality networks, such as those networks seen in hotels and hospitals. In particular, our approach aims to determine the total number of VoD sessions that can be sustained by an existing hospitality network, while satisfying the QoS requirements of all network services, and at the same time leaving adequate capacity for future growth. We gauge the capacity of the hospitality network to sustain VoD services using both analysis and simulation. The capacity is gauged considering VoD quality of service requirements of throughput and delay constraints. Our analysis utilizes the principles of queuing theory, and our simulation is performed using OPNET simulation. Copyright © 2011 John Wiley & Sons, Ltd.     

Localizing non‐line‐of‐sight nodes in Vehicluar Adhoc Networks using gray wolf methodology

Vehicular ad hoc networks (VANETs) evolved by adopting the principles of mobile ad hoc networks. This network has been designed to deploy safety related application in vehicular node in the less chaotic environment in road scenarios. Vehicles exchange emergency messages through direct communication. In a practical situation, a direct communication between the vehicles is not possible, and it is prohibited by either static or dynamic obstacles. These obstacles prevent the direct communication between the vehicles and can craft a situation like non‐line of sight (NLOS). This NLOS becomes a perennial problem to the researchers as it creates localization and integrity issues which are considered to be important for road safety applications. Handling the moving obstacles is found to be a challenging one in the VANET environment as obstacles like truck are found to have similar characteristics of the vehicular nodes. This paper utilizes the merits of the meta‐heuristic approach and makes use of the improved gray wolf optimization algorithm for improving the localization and integrity services of the VANET by overcoming the NLOS conditions. The proposed methodology is found to have improved neighborhood awareness, reduced latency, improved emergency message delivery rate, and reduced mean square error rate.     

A system for providing load‐aware virtual network service in a software‐defined data center network

Virtual networks may be used in a cloud data center to provide personalized networking services for the applications running in the cloud. As the virtual networks come to the data center and leave it, the data center network load may become unbalanced where some parts of the data center has accommodated many virtual networks while a few virtual networks are mapped to other parts of the data center. This situation may lead to packet loss and service level agreement violations in an oversubscribed data center. This unbalanced state of the load in data center can be resolved by migration of virtual networks from overloaded parts of the data center to places where the load is in a lower level. This paper presents implementation details of the prototype of a system that provides virtual networking service in a cloud data center and focuses primarily on virtual network migration as a means for controlling the state of load in data center. Experimental results show that the system has an acceptable performance in reducing the packet loss ratio and keeping the load in a balanced state.     

Practical and analytical approaches for designing scalable on‐demand policy‐based resource allocation in stateless IP networks

Today the policy‐based management (PBM) approach is recognized as an efficient solution to simplify the complex task of managing and controlling networks. To this end, the Internet Engineering Task Force (IETF) has introduced a reference framework to build PBM systems. However, this framework only addresses the provisioning of relatively long validity period services based on predefined service‐level agreements. Furthermore, very little work addresses the scalability properties of the instantiation of this framework in a real network. This work aims to extend the IETF PBM framework in order to support dynamic provisioning of short‐term services (end‐system signalling) as well as an instantiation scheme that is scalable (distributed provisioning of edge routers). This instantiation scheme is based on the distribution of the provisioning process while keeping centralized only the parts that involve critical resources, namely bandwidth brokerage. The performance properties of the proposed scheme are then demonstrated throughout both extensive experimentation and an analytical study. The extension of this performance analysis to the case where multiple bandwidth brokers are used is also discussed. The results of this work are intended to be used as a guideline to help network operators to design a scalable PBM system in order to offer to their customers services with quality of service assurance on an on‐demand basis. Copyright © 2011 John Wiley & Sons, Ltd.     

Error repair for broadcast transmissions in DVB‐H systems

People travelling in public transportation vehicles are foreseen to be a relevant use case of future Digital Video Broadcast—Handhelds (DVB‐H) systems. However, it is also one of the critical user cases, since, besides the vehicle penetration loss, the received signal quality is strongly affected by the high mobility of the users, which is accompanied by temporary shadowing and fast fading. On the other hand, mobility can be also beneficial thanks to the bursty character of DVB‐H transmissions, as additional repair data can be sent in the time intervals between original service bursts in order to hide the coverage discontinuities from the users' perception. In this way, users which miss the original transmission have more chances to receive the information correctly. By managing the amount of repair data the network operator can trade system capacity and network latency for improved vehicular user satisfaction in a DVB‐H network with imperfect coverage of the service area (as perceived by the vehicular users). To illustrate the potential of this approach, we evaluate the mentioned trade‐off in a DVB‐H system dimensioned for pedestrian outdoor users, for both streaming and filecasting services. To enable an easy and efficient implementation of the repair mechanisms, we adopt application layer forward error correction (FEC), as it can provide a multi‐burst protection of the transmission. Copyright © 2008 John Wiley & Sons, Ltd.     

Link repair in managed multi‐domain connections with end‐to‐end quality guarantees

The Internet is a platform providing connection channels for various services. Whereas for services like email the best‐effort nature of the Internet can be considered sufficient, other services strongly depend on service‐specific connection quality parameters. This quality dependence has led to dedicated content distribution networks as a workaround solution for services like YouTube. Such workarounds are applicable to a small number of services only. With the global application of the Internet, the impact of quality of service varies from annoyance due to jitter in VoIP communication to endangering human lives in telemedicine applications. Thus network connections with end‐to‐end quality guarantees are indispensable for various existing and evolving services. In this paper we consider point‐to‐point multi‐domain network connections for which the end‐to‐end quality has to be assured. Our contribution includes the classification of fault cases in general and countermeasures against end‐to‐end performance degradation. By correlating events and reasonable countermeasures, this work provides the foundation for quality assurance during the operation phase of end‐to‐end connections. We put our contribution in the context of a vision of global‐goal‐aware self‐adaptation in computer networks and outline further research areas that require a similar classification to the work provided here. Copyright © 2012 John Wiley & Sons, Ltd.     

基于REST风格的混杂感知车载网信息服务设计

实时可靠地获得全面的车载感知服务信息是车载网络发展的"瓶颈"问题。混杂感知车载网(HSVN)兼有无线传感器网络(WSN)和车载自组网(VANET)的特点,为车载用户提供了大量车载信息,是车载网络的发展趋势。表述性状态转移(REST)架构统一了资源格式和交互形式,在服务器和客户端间进行无状态服务,有利于异构问题的解决。文章基于HSVN的信息服务特征,提出一种新型车载网络框架和服务模型,能提高车载感知信息的服务交互能力;基于REST架构理念,采用HSVN中信息服务资源设计方法,为异构网络下的信息交互系统提供一种轻量化的实现途径。     

A routing layer-based hierarchical service advertisement and discovery for MANETs

The implementation of mobile ad hoc networks (MANETs) is steadily increasing. MANETs are especially popular in locations that lack a fixed communication infrastructure. To achieve zero-configuration MANETs, as well as quick and easy access to network resources, resources must be well managed by the network. This paper proposes a hierarchical service discovery and advertisement protocol (HSDAP) implemented in the routing layer. HSDAP queries services by piggybacking service REQuest (SREQ) packets on routing packets to reduce overhead and energy consumption. We extend the cluster-based routing protocol (CBRP) to improve service management hierarchy. Simulation results show that adding service discovery and advertisement (SDA) functions to CBRP does not significantly affect overhead. SDA overhead, routing overhead, energy consumption, and SDA delay are significantly less than the extended zone routing protocol. Furthermore, SDA hit ratio of the proposed protocol is greater than 86% for various levels of mobility. The proposed HSDAP is robust and scalable.