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.     

Maximizing service availability for secure satellite broadcasting

Cryptography is the most suitable technique to protect the access to subscribed value‐added services for mobile applications provided through satellite broadcasting (e.g. localization and mobile TV). However, if a temporary loss of signal is experienced by receivers, not only the data streaming is compromised, but also the key management‐related messages. Hence, when the signal is received again, it is impossible for the receivers to decrypt it. One way to overcome this issue is the re‐transmission of keys to guarantee that the largest set of legitimate receivers has the updated (set of) keys. In this paper we analyze the problem of key update in a mobile user context in order to maximize the service availability. In particular, we provide the following contributions: we propose a mathematical model that captures all the relevant features of mobile users. Then, we formally prove a few novel results on the structure of the admissible rekeying sequence. These results are used to design a scheduling algorithm for key broadcasting that, according to our model, minimizes the number of mobile users that are prevented from updating their crypto keys, hence continuing accessing the service. Finally, simulation results support our theoretical findings. Copyright © 2008 John Wiley & Sons, Ltd.     

A fault‐tolerant group key agreement protocol exploiting dynamic setting

A fault‐tolerant group key agreement is an essential infrastructure for Internet communication among all involved participants; it can establish a secure session key no matter how many malicious participants exit simultaneously in an effort to disrupt the key agreement process. Recently, Zhao et al. proposed an efficient fault‐tolerant group key agreement protocol named efficient group key agreement that can resist denial‐of‐service attacks, reply attacks, man‐in‐middle attacks, and common modulus attacks; it can also preserve forward secrecy with lower computational cost than previous protocols. We show that it is still vulnerable to active attacks by malicious participants and modify the corresponding security weakness adaptively. Furthermore, we propose an efficient fault‐tolerant group key agreement based on a binary tree structure and enhance it to a dynamic setting where participants can leave or join the group arbitrarily according to their preferences with instant session key refreshment. Additionally, our session key refreshment is based on secure key updating to protect forward/backward confidentiality and is resistant to active/passive attacks. The performance analysis shows that our proposed protocol has lower computational cost and little additional communication cost exploiting dynamic setting. Copyright © 2013 John Wiley & Sons, Ltd.     

Using group mobility and multihomed mobile gateways to connect mobile ad hoc networks to the global IP Internet

Connecting multihop mobile ad hoc wireless networks (MANETs) to the Internet would enable MANET nodes to share wireless Internet access with mobile hosts that are one‐hop away from their foreign networks. The integration of MANETs and the global Internet, however, faces an obstacle due to their network architectural mismatches regarding their infrastructure, topology, and mobility management mechanisms. Solutions to the integration problem should introduce an intermediate facility with hybrid mechanism, enabling it to connect to both networks. The quality of the multihop wireless Internet access service provided to MANET nodes depends on the design quality of this facility in order for MANET nodes to enjoy their Internet connectivity anywhere and anytime without much disconnections. In this paper, we propose hierarchical architecture that uses group mobility and multihomed mobile gateways, and present and analyse different simulations results. A multihomed mobile gateway can simultaneously connect to multiple Mobile IP foreign agents, provided it is located within their overlapping coverage area. It runs updated versions of the destination‐sequenced distance vector (DSDV) and Mobile IP protocols, and is responsible for providing MANET nodes with wireless Internet access though they are multiple wireless hops away from the edge of the Internet. The rationale behind using multihoming is to increase reliability of the Internet access service and enhance performance of the integrated network. Copyright © 2006 John Wiley & Sons, Ltd.     

Predicting group partitions in mobile ad hoc networks

Group mobility is prevalent in many mobile ad hoc network applications such as disaster recovery, military actions, etc., and group partitions are unavoidable in such kinds of dynamic networks. Group partition may occur when mobile nodes move in diverse mobility patterns and causes the network to be partitioned into disconnected components. It may result in severe link disconnections, which then interrupt intergroup communications. By examining the group mobility pattern, we can predict the possibility of network partitions, and thus minimize the amount of communication disruptions. In this paper, we introduce a system for predicting potential group partitions in mobile ad hoc networks. On the basis of historical group mobility information, a quadratic regression model is formulated to predict the direction and speed of a group's movement. A group's micromovement is ignored and is replaced by significant linear displacement to measure its mobility to improve the prediction accuracy. We also discuss the notion of safe distance between adjacent groups, based on which the time duration before the occurrence of group partitioning can be measured. Experimental results show that our proposed prediction method demonstrates its effectiveness and efficiency in group partition predictions such that remedial actions can be taken in advance to avoid network disconnection. Copyright © 2011 John Wiley & Sons, Ltd.     

Fusion of digital television,broadband Internet and mobile communications—Part II: Future service scenarios

This is the second part of the tutorial paper following the previous tutorial paper describing enabling technologies in digital video broadcasting (DVB) system. The paper presents the current and future operational scenarios for DVB via satellite (DVB‐S) system. Review of the current state‐of‐the‐art technologies consisting of integration of broadband Internet and mobile communications and integration of broadband Internet and DVB are given. The future operational scenarios emphasize the fusion of DVB systems with other technologies in terms of network fusion and terminal fusion. For satellite service scenarios, it also takes into consideration mobility management and standard quality‐of‐service mechanism issues, such as integrated services and differentiated services. Several research directions for providing seamless services regardless of network, access technology and terminal in the fusion network are also highlighted in this paper. Copyright © 2007 John Wiley & Sons, Ltd.     

Adaptive paging schemes for group calls in mobile broadband cellular systems

In this paper, we analyze the problem of efficient paging for group call searches under realistic mobility patterns. Taking as a basis a location update scheme, based on the definition of an adaptive macro‐location area, adapted to the mobility pattern of the terminals, we characterize the residence probabilities in each location area of a generic macro‐area. With this information, we propose and evaluate different sequential group paging strategies, also taking into account their computational cost. Results show the suitability of some of the proposals (semiadaptive and hybrid schemes) and its applicability to new packet‐based broadband cellular systems. Copyright © 2010 John Wiley & Sons, Ltd.     

中国移动互联网应用服务领域发展研究

近些年移动互联网各领域快速发展.在用户方面,移动用户规模快速增长,2016年移动互联网用户总数达到20亿.在终端方面,2016年,全球移动智能终端总共出货量达到15亿台,同比增长约5％.在应用方面,移动应用规模超过1000万款,累计下载规模超过万亿.与此同时,移动应用产业飞速发展,其不断融入新型能力,在传感、识别等方向均有突破,并快速融入到人们日常生活的方方面面.随着移动应用服务的发展,其同样出现了诸多问题,危害用户合法权益,影响产业健康持续发展.重点阐述当前移动应用领域发展现状,解析其特点与存在问题,并探索保障行业健康持续发展的相关措施.     

A secure and efficient password‐authenticated group key exchange protocol for mobile ad hoc networks

Password‐authenticated group key exchange protocols enable communication parties to establish a common secret key (a session key) by only using short secret passwords. Such protocols have been receiving significant attention. This paper shows some security weaknesses in some recently proposed password‐authenticated group key exchange protocols. Furthermore, a secure and efficient password‐authenticated group key exchange protocol in mobile ad hoc networks is proposed. It only requires constant round to generate a group session key under the dynamic scenario. In other words, the overhead of key generation is independent of the size of a total group. Further, the security properties of our protocol are formally validated by a model checking tool called AVISPA. Security and performance analyses show that, compared with other related group key exchange schemes, the proposed protocol is also efficient for real‐world applications in enhancing the security over wireless communications. Copyright © 2011 John Wiley & Sons, Ltd.     

A secure group key management scheme for hierarchical mobile ad hoc networks

In this paper, we present a secure group key management scheme for hierarchical mobile ad hoc networks. Our approach aims to improve both scalability and survivability of group key management for large-scale wireless ad hoc networks. To achieve our goal, we propose the following approaches: (1) a multi-level security model, which follows a modified Bell-La Padula security model that is suitable in a hierarchical mobile ad hoc networking environment, and (2) a decentralized group key management infrastructure to achieve such a multi-level security model. Our approaches reduce the key management overhead and improve resilience to any single point failure problem. In addition, we have developed a roaming protocol that is able to provide secure group communication involving group members from different groups without requiring new keys; an advantage of this protocol is that it is able to provide continuous group communication even when the group manager fails.     

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.     

Mobility assessment on‐demand (MAOD) routing protocol for mobile ad hoc networks

In ad hoc wireless networks, the high mobility of hosts is usually a major reason for link failures. The general ‘shortest path’ based routing protocols may not lead to stable routes. In this paper, we propose a mobility assessment on‐demand (MAOD) routing protocol to select a stable route in order to enhance system throughput and performance. An error count parameter is used to judge whether a host is highly mobile. The proposed MAOD routing protocol is an on‐demand routing protocol similar to dynamic source routing (DSR). The difference between MAOD and DSR is in the path selection method. Because MAOD takes the mobility of hosts into consideration, it will select a more stable and reliable path than DSR. In comparison, DSR only considers whether this route is a shortest path or not. Finally, the system performance is analyzed by using the global mobile simulation (GloMoSim) simulator. We can observe that MAOD routing protocol outperforms DSR routing protocol especially in the high mobility environment. Copyright © 2004 John Wiley & Sons, Ltd.     

A novel batch-based group key management protocol applied to the Internet of Things

Many applications for ad hoc networks are based on a point-to-multipoint (multicast) communication paradigm, where a single source sends common data to many receivers, or, inversely, on a multipoint-to-point communication paradigm, where multiple sources send data to a single receiver. In such scenarios, communication can be secured by adopting a common secret key, denoted as “group key”, shared by multiple communication endpoints. In this work, we propose a novel centralized approach to efficiently distribute and manage a group key in generic ad hoc networks and Internet of Things, while reducing the computational overhead and network traffic due to group membership changes caused by users’ joins and leaves. In particular, the proposed protocol takes advantage of two possible leave strategies: (i) at a pre-determined time selected when the user joins the group or (ii) at an unpredictable time, as in the case of membership revocation. The proposed protocol is applied to two following relevant scenarios: (i) secure data aggregation in Internet of Things (IoT) and (ii) Vehicle-to-Vehicle (V2V) communications in Vehicular Ad hoc Networks (VANETs).     

A lightweight convergent personal mobile service delivery approach based on phone book

Mobile phone users are demanding an efficient convergent communication approach for efficient communication and information sharing with their real life social circles. Unfortunately, the existing telecom services and the popular Internet services are not organically integrated to provide convenient convergent services. To overcome this issue, one of the promising convergent communication services considered by telecom carriers is RCS (Rich Communication Suite). However, existing issues, such as insufficient interoperability among different operators, shortage of terminals and heavy dependence on large‐scale IP multimedia subsystem (IMS) network deployment, mean that it will take time to implement RCS across worldwide networks and for it to become a service equally universal as voice and short message. Instead of a heavyweight RCS solution, in this paper, we propose a lightweight, quick deployment mobile phone book application system based on cloud computing without a fully deployed IP multimedia subsystem infrastructure, which seamlessly integrates traditional telecommunication services, instant messaging services, social networking services and automatic contact information management. Based on this, ‘Telco‐OTT’ service provision approach, telecom carriers can allow their subscribers to enjoy conveniently the rich convergent personal service experience quickly without a large initial investment. Thus, it is a low‐risk opportunity for telecom carriers to meet subscriber demand for advanced user‐centric convergent service features. Copyright © 2013 John Wiley & Sons, Ltd.     

一种基于用户行为预测的群移动性管理模型

移动性管理是未来5G移动的重要组成部分,如何均衡寻呼负载和位置更新开销,从而合理利用无线资源是当前的研究重点.提出了一种新的群移动性管理(GMM)方案,可以针对具有相同运动特征的用户进行集中式管理,从而可以减少单个用户移动性管理(SMM)时存在的重复开销.仿真结果表明,GMM比SMM可以获得更佳的运行开销.     

A routing layer based approach for energy efficient service discovery in mobile ad hoc networks

Service discovery can be greatly enhanced in terms of efficiency, both regarding service discoverability and energy consumption, by piggybacking service information into routing messages. Thus, service discovery does not generate additional messages and a node requesting a service, in addition to discovering that service, it is simultaneously informed of the route to the service provider. We extended the Zone Routing Protocol in order to encapsulate service information in its routing messages. Our extended protocol, E‐ZRP, may be seen as a representative of routing layer protocols providing service discovery functionality. Simulations demonstrate the superiority of this routing layer‐based service discovery scheme over that of a similar, but application layer based service discovery scheme. In order to have a thorough evaluation of our approach we introduced a new metric, called Service Availability Duration (SAD), which characterizes the ‘quality’ of discovered services and experimentally examines the implications of network density and node mobility on the availability of services discovered with E‐ZRP, as a typical representative of routing layer based service discovery protocols. Copyright © 2008 John Wiley & Sons, Ltd.     

IP组播组管理协议及其在二层的实现

介绍了IP网络组播相关知识与协议体系 ,详细解析了互联网组管理协议 ,并提出该协议以太网二层的实现机制。     

A multi‐anchoring approach in mobile IP networks

Many recent mobility solutions, including derivatives of the well‐known Mobile IP as well as emerging protocols employed by future Internet architectures, propose to realize mobility management by distributing anchoring nodes (Home Agents or other indirection agents) over the Internet. One of their main goals is to address triangle routing by optimizing routes between mobile nodes and correspondent nodes. Thus, a key component of such proposals is the algorithm to select proper mobility anchoring nodes for mobile nodes. However, most current solutions adopt a single‐anchoring approach, which means each mobile node attaches to a sole mobility anchor at one time. In this paper, “we argue that the single‐anchoring approach has drawbacks when facing various mobility scenarios. Then, we offer a novel multi‐anchoring approach that allows each mobile node to select an independent mobility anchor for each correspondent node. We show that in most cases our proposal gains more performance benefits with an acceptable additional cost by evaluation based on real network topologies. For the cases that lead to potential high cost, we also provide a lightweight version of our solution which aims to preserve most performance benefits while keeping a lower cost. At last, we demonstrate how our proposal can be integrated into current Mobile IP networks. Copyright © 2017 John Wiley & Sons, Ltd.     

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.     

基于移动代理的OBS网络的信令协议方案

文章提出一种基于移动代理和光突发交换(OBS)的光链路信令建立方法和协议方案.将主动包的结构应用于移动代理,使信令消息和数据流概括到一个突发包头(BHP)中,以此来缩短一个光路的建立时间.该方案可以实现分布式处理链路,以减轻网络中一个节点的工作量和加强每个网络节点的并行运算能力.