Service-oriented broadband wireless network architecture - [Guest editorial]

In the past few years, broadband wireless networks have been very attractive as a key technology for providing Internet access because of quick and cost-effective deployments. In addition to the features of high data rate and large coverage, broadband wireless networks also promise to rapidly provide access to locations in the world?s rural and developing areas where broadband is currently unavailable, as well as compete for urban market shares. Till now, most existing efforts have been focused on basic access capability. However, to successfully operate broadband wireless networks, a crucial issue must be addressed: how to support a variety of services and applications within the broadband wireless networks? As an example, there is an increasing need to efficiently support applications such as voice over IP (VoIP), video streaming, music downloading, IP TV, and many others.     

Topology control for service-oriented wireless mesh networks - [Service-oriented broadband wireless network architecture]

Topology control is one of the most critical design issues in multihop wireless networks. Topology control has been investigated extensively in the literature. Nevertheless, it is noted that most existing studies do not consider the requirements on upper layer applications or services. In this article we address the topology control issues on service-oriented wireless mesh networks. In particular, we provide a comprehensive survey of existing works on topology control from a service- oriented perspective. We then propose a general framework for topology control in service- oriented WMNs. To demonstrate the effectiveness of the framework, we conduct a case study in which the main objective is to maximize the overall throughput in a network with random unicast traffic. The performance of this topology control scheme is evaluated by numerical results. In addition, it is illustrated that the generated topology can support advanced technologies, including network coding and physical-layer network coding, which can significantly improve the throughput capacity of a network.     

Security in service-oriented vehicular networks - [Service-oriented broadband wireless network architecture]

Service-oriented vehicular networks support diverse infrastructure-based commercial services including Internet access, real-time traffic concerns, video streaming, and content distribution. The success of service delivery in vehicular networks depends on the underlying communication system to enable the user devices to connect to a large number of communicating peers and even to the Internet. This poses many new research challenges, especially in the aspects of security, user privacy, and billing. In this article we first identify the key requirements of authentication, privacy preservation, and billing for service delivery in vehicular networks. We then review the existing industrial and academic efforts on service- oriented vehicular networks. We also point out two security challenges, minimizing vehicleto- infrastructure authentication latency and distributed public key revocation, which are considered among the most challenging design objectives in service-oriented vehicular networks. A novel fast vehicle-to-infrastructure authentication based on a vehicle mobility prediction scheme and an infrastructure-based short-time certificate management scheme are then proposed to address these two challenges.     

Network-coding-based scheduling and routing schemes for service-oriented wireless mesh networks - [Service-oriented broadband wireless network architecture]

Service-oriented wireless mesh networks have recently been receiving intensive attention as a pivotal component to implement the concept of ubiquitous computing due to their easy and cost-effective deployment. To deliver a variety of services to subscriber stations, a large volume of traffic is exchanged via mesh routers in the mesh backbone network. One of the critical problems in service-oriented wireless mesh networks is to improve the network throughput. Wireless network coding is a key technology to improve network throughput in multihop wireless networks since it can exploit not only the broadcast nature of the wireless channel, but also the native physical-layer coding ability by mixing simultaneously arriving radio waves at relay nodes. We first analyze the throughput improvement obtained by wireless network coding schemes in wireless mesh networks. Then we develop a heuristic joint link scheduling, channel assignment, and routing algorithm that can improve the network throughput for service-oriented wireless mesh networks. Our extensive simulations show that wireless network coding schemes can improve network throughput by 34 percent.     

A quality-driven decision engine for live video transmission under service-oriented architecture - [Service-oriented broadband wireless network architecture]

Service-oriented architecture provides a solution to the increasing network complexity due to ever-growing heterogeneous networks. As the most significant component of SOA, the decision engine is to create a workflow, defined as a sequence of individual data processing entities, for providing end-to-end QoS of a given task. Although the workflow of video transmission is generally known, existing solutions are often monolithic. Furthermore, there is no decision engine to select a workflow based on the best user-perceived quality. In this article we propose a service-oriented decision engine framework, which consists of a decision engine, a performance evaluation component, and other major SOA components to support real-time video transmission over wireless multihop networks, aiming to provide the best user-perceived video quality under application-centric QoS constraints. Based on the investigation of the state of- the-art research efforts on SOA, some key issues for wireless live video transmission are discussed, and a case study for live video transmission is given to illustrate the proposed scheme. The superior performance of the proposed service-oriented decision engine is validated by experimental results.     

Using P2P overlays to provide QoS in service-oriented wireless networks - [Service-oriented broadband wireless network architecture]

An increasing number of applications require some form of guarantees from the network, in terms of bandwidth or access and transfer delay. This demand for quality of service can be met by means of different mechanisms, depending on the networks being traversed, as well as the degree of integration of the services with the communication infrastructure. Whereas end-to-end QoS provision is still an open problem, several possibilities now exist in local environments. The article investigates the capabilities offered by a P2P overlay for distributed bandwidth management in a controlled ad hoc deployment, to support specific requirements in service-oriented wireless networks. The mechanism proposed allows complementing the core functionalities of the IEEE 802.11e protocol, and enhancing them to handle local mobility and dynamic requests for bandwidth. The performance evaluation is provided in an emulated environment to show the effectiveness of the presented approach.     

Downlink scheduling for multimedia multicast/broadcast over mobile wimax: connection-oriented multistate adaptation - [Service-oriented broadband wireless network architecture]

With its comprehensive QoS support and ubiquitous coverage, the mobile WiMAX network offers promising opportunities for unwiring the last mile connectivity to Internet. However, stringent QoS demands of multimedia applications entail studies on service-oriented radio resource management. This article systematically examines the design issues and the state of the art of multimedia downlink scheduling in the multicast/broadcast-based WiMAX system. We propose a viable end-to-end framework, connection-oriented multistate adaptation, by considering cross-layer adaptations in source coding, queue prioritization, flow queuing, and scheduling. Its performance is confirmed by simulations on important metrics, showing that the framework can effectively accommodate heterogeneity in link variations, queue fluctuations, and reception diversities.     

A radio bypass [wireless broadband]

This paper explains why Malaysian Internet service provider, Jaring, is creating a 1-megabit per second wireless service in an attempt to compete better with the national carrier, Telekom Malaysia Berhad. Jaring aims to provide a wireless equivalent to DSL that can also carry high-quality telephone calls. While Jaring's transformation from mere service provider to network operator comes with considerable risks, the potential rewards are too great to ignore and the risks of doing nothing are greater still. To mitigate the risks, however, Jaring chose equipment that can operate on a variety of spectral bands and should be able to weather the storms of technological change.     

海上无线宽带网络架构研究现状及相关技术展望

近年来,国家智慧海洋战略的实施对海上无线通信网络全方位覆盖、海上应急管理水平和信息服务能力等提出更高的要求。从部署海上无线宽带网络的实际需求出发,总结了海上无线宽带网络架构的国内外研究现状,概括了海上无线宽带技术的特点,最后展望了海上无线宽带网络技术的研究前景。在广阔的海洋上部署高速低成本的无线宽带网络定会为海洋产业的发展提供有力的通信保障和技术支持。     

业务驱动的临近空间光信息栅格体系结构

结合空间信息栅格和光网络技术,提出了业务驱动的临近空间光信息栅格的概念,并从栅格资源、栅格服务和栅格应用3个层面深入研究了临近空间光信息栅格的体系结构。该临近空间光信息栅格可根据任务需要进行信息的快速收集、处理、存储、分发、管理和对抗,对其体系结构的研究可为进一步研究临近空间信息栅格提供有益的参考。     

Viva mesh Vegas [mesh wireless network]

In this paper, the mesh wireless network established by Cheetah Wireless Technologies Inc. is discussed. Cheetah's mobile wireless network is one of the first municipal installations to use mesh wireless technology, which allows users to access the Internet anywhere within the coverage area even if they're driving at 100 kph. Mesh networks have several key advantages over traditional wireless solutions, such as Wi-Fi or cellphones. Benefits include higher speeds, less susceptibility to radio interference, and greater resistance to network congestion. These networks also offer better coverage, the ability to prioritize different types of users, geolocation capabilities, tighter security, faster deployment, and a degree of immunity to catastrophic network failures.