Running cellular/PWLAN services: practical considerations for cellular/PWLAN architecture supporting interoperator roaming

To offer wireless data access services that are more efficient than GPRS or UMTS networks, public WLANs are in a predominant position to embrace the wireless broadband era. Reusing the existing mechanisms for user authentication, access control, billing, and roaming handling procedures in mobile territory to construct a complementary network, public WLAN (PWLAN) has drawn the attention of cellular operators such as Vodafone and T-Mobile. In this article we aim to investigate a practical end-to-end PWLAN architecture capable of using GPRS/UMTS SIM-based authentication for current mobile users and carrying out Web-based authentication for occasional users without SIM modules simultaneously. Additionally, we consider a confederation of various PWLAN service providers by a RADIUS-based roaming mechanism to leverage the existing resources of cellular operators. The proposed considerations and guidelines provide a baseline skeleton to build an extendable environment and successfully construct a flexible cellular/PWLAN hotspot in mobeeLAN service.     

Wireless in-building network architecture and protocols

The topology, protocols and architecture for an 18-GHz wireless in-building network (WIN) aimed at office environments are described. The problems of controlling an array of directional antennas, using half-duplex radios and compensating for channel errors are addressed. The protocols provide robustness in the face of changing radio environment that requires no user intervention and provides low user delay and high system throughput     

无线城市应用平台建设方案

文章介绍了无线城市的发展历程,分析了无线城市业务及应用平台建设思路,提出了无线城市运营思路,并对无线城市的发展进行了探讨.     

NCIH services, architecture, and implementation

The telecommunications planners for the North Carolina State Government recognising the potential of asynchronous transfer mode and synchronous optical network, asked BellSouth, Carolina Telephone, and GTE to develop a proposal for a network based on ATM and SONET to enable a multitude of high-speed data and video applications throughout the state. This B-ISDN, now known as the North Carolina Information Highway (NCIH), has become widely recognized as a model for the National Information Infrastructure (NII). The services provided by the NCIH are designed to be able to support numerous emerging applications that are expected to provide significant benefits in the areas of education, health care, crime control, economic development, and government     

Broadband networks and services: architecture and control

Broadband networks to support a diverse combination of media and services present two interrelated challenges to the designers: how to devise the proper network architectures to efficiently deliver information, and how to realize the control and software infrastructure for end-to-end support of broadband applications. The new networks and applications that represent the future of interactive digital broadband are not driven by technology alone. We should recognize that the true foundation of the future information networking business involves the uses and benefits that it produces. The applications that are driving the information age are numerous, coming from the areas of entertainment, enterprise systems, telecommunications, education, health, etc. The use of client-server distributed object computing technologies is at the foundation of all the software systems that have been designed and implemented. There are still many Issues to he resolved in the application of this software technology, but it is clear that we must rely on distributed software designs to support the features of interactive broadband services. Concerns over the ability to manage complexity and scalability in these large distributed software systems are a common thread and an indication that the technology still needs to mature     

Wireless Internet over LMDS: architecture and experimentalimplementation

LMDS is currently a promising emerging technology in broadband fixed wireless communications. The cellular structure, high data rates, and flexibility make it perfect for multimedia, digital television, and interactive services. These high-bandwidth multimedia services received most of the research attention until lately. There has been a clear gap when considering UDP/TCP/IP and other data services over LMDS. We examine the ramifications of using standard TCP/IP data communication over a two-layer LMDS system. We argue that the former emphasis only on multimedia and ATM-based communication over LMDS was a mistake. The most exciting prospect for LMDS should be in the role of enabling Internet and data services together with multimedia. We introduce a basic architecture for two-layer IP-LMDS based on a trial network built between 1996 and 2000     

A multilayer differentiated protection services architecture

Metropolitan area and long-haul networks are migrating toward the deployment of optical mesh technologies. This requires, among other things, a new generation of highly intelligent protection and restoration mechanisms to perform functions of protection and bandwidth management. We introduce an architecture that provides differentiated protection services across multiple layers of network hierarchy. A connection at any client layer can request a protection against resource failures at any lower layer. A key aspect of the architecture is the hierarchical tree organization of shared risk link group (SRLG) resources. They represent routing-related failures across all layers of protocol stack. The architecture is very scalable in terms of communicating link-state and bandwidth information between adjacent layers. SRLG trees are used to aggregate this information and provide a summary to the client layer. We discuss the requirements and challenges for routing and signaling mechanisms in order to support the proposed architecture. The complexity of this architecture is evaluated and compared with the complexity of a nonhierarchical alternative.     

A scale database architecture for network services

A radical technology for databases, called the Datacycle architecture, which implements a relational model for network services and scales to support throughput of thousands of transactions per second is proposed. A set of data manipulation primitives useful in describing the logic network services is described. The use of the relational model together with an extended structured-query-language-like query language to describe 800 service, network automatic call distribution, and directory-assisted call completion services, is examined. The architectural constraints on the scalability of traditional database systems is reviewed, and an alternative, the Datacycle architecture is presented. The Datacycle approach exploits the bandwidth of fiber optics to circulate database contents among processing nodes (e.g. switching offices or other network elements) in a network, providing highly flexible access to data and controlling the administrative and processing overhead of coordinating changes to database contents. A prototype system operating in the laboratory is described. The feasibility of the Datacycle approach for both existing and future applications is considered     

未来移动通信网的位置服务体系结构

引 言位置服务(LCS)是未来无线移动通信网的一个组成部分。无论移动终端用户处于空闲或通话状态,这种新型的网络服务都能够将其地理定位。未来系统包括第三代(3G)系统(如UTRAN和IS-2000)以及现有系统(GSM,IS-95和IS-136)的增强型。此服务最初是为满足公共安全部门的规定。安全部门在其权限范围内,需     

Distributed servers architecture for networked video services

In an on-demand video system, the video repository generally has limited streaming capacities and may be far from the users. In order to achieve higher user capacity and lower network transmission cost, distributed servers architecture can be used, in which multiple local servers are placed close to user pools and, according to their local demands, dynamically cache the contents streamed from the repository. We study a number of caching schemes as applied in the local servers depending on whether the repository is able to multicast movie contents to the local servers or not, and whether the local servers can exchange their cached contents among themselves or not. Our caching schemes keep a circular buffer of data for the movie requested, and hence movies are partially cached. By adjusting the size of the buffer, such caching is able to achieve better tradeoff between network channels and local storage as compared to the traditional caching in which a movie is treated as an entity. For each caching scheme, we study the tradeoff between the local storage and the network channels, and address how the total cost of the system can be minimized by appropriately sizing the buffer. As compared to a number of traditional operations (request batching and multicasting, true-VOD, etc.), we show that distributed servers architecture is able to achieve much lower system cost to offer on-demand video services     

A control and management architecture supporting autonomic NFV services

Photonic Network Communications - The proposed control, orchestration and management (COM) architecture is presented from a high-level point of view; it enables the dynamic provisioning of services...     

Hardware-software architecture of the SWAN Wireless ATM network

The SWAN (Seamless Wireless ATM Network) system provides end-to-end ATM connectivity to mobile end-points equipped with RF transceivers for wireless access. Users carrying laptops and multimedia terminals can seamlessly access multimedia data over a backbone wired network while roaming among room-sized cells that are equipped with basestations. The research focus on how to make ATM mobile and wireless distinguishes SWAN from present day mobile-IP based wireless LANs. This paper describes the design and implementation of the ATM-based wireless last-hop, the primary components of which are the air-interface control, the medium access control, and the low-level ATM transport and signalling.The design is made interesting by its interplay with ATM; in particular, by the need to meaningfully extend over the wireless last-hop the service quality guarantees made by the higher level ATM layers. The implementation, on the other hand, is an example of hardware-software co-design and partitioning. A key component of the wireless hop implementation is a custom designed reconfigurable wireless adapter card called FAWN (Flexible Adapter for Wireless Networking) which is used at the mobiles as well as at the basestations. The functionality is partitioned three-way amongst dedicated reconfigurable hardware on FAWN, embedded firmware on FAWN, and device driver software on a host processor. Using an off-the-shelf 625 Kbps per channel radio, several of which can be supported by a single FAWN adapter to provide multiple channels, per-channel unidirectional TCP data throughput of 227 Kbps (or, 454 Kbps bidirectional) and per-channel unidirectional native ATM data throughput of 210 Kbps (or, 420 Kbps bidirectional) have been obtained.     

Wireless LAN access network architecture for mobile operators

The evolution of IP-based office applications has created a strong demand for public wireless broadband access technology offering capacity far beyond current cellular systems. Wireless LAN access technology provides a perfect broadband complement for the operators' existing GSM and GPRS services in an indoor environment. Most commercial public wireless LAN solutions have only modest authentication and roaming capability compared to traditional cellular networks. This article describes a new wireless LAN system architecture that combines the WLAN radio access technology with mobile operators' SIM-based subscriber management functions and roaming infrastructure. In the defined system the WLAN access is authenticated and charged using GSM SIM. This solution supports roaming between cellular and WLAN access networks and is the first step toward an all-IP network architecture. The proto-type has been implemented and publicly verified in a real mobile operator network     

Wireless personal area networks architecture and protocols for multimedia applications

Wireless Personal Area Networks (WPANs) are an emerging technology for future short-range indoor and outdoor multimedia and data centric applications. Two types of WPANs have been standardized by the IEEE 802.15 working group; namely: High data Rate WPANs (HR-WPANs) and Low data Rate WPANs (LR-WPANs). These standards define the network architecture, the physical layer and the medium access control sublayer for these systems. A tremendous number of performance studies through mathematical analysis and simulation have been published. Also, many products have appeared in the market which indicate a clear sign of a quick acceptance to the published standards. An organized review of the network architecture, the physical layer specifications, the Medium Access Control (MAC) protocols and the general network operation concepts of the WPAN systems deserves time and effort to be presented in a collective manner. In this paper we describe the concept of WPANs and its applications. Then, the communication architecture and the allocated frequency spectrum for WPAN operation are explained. The developed MAC sublayer protocols in the literature are explored.     

A routing architecture for mobile integrated services networks

A drawback of the conventional Internet routing architecture is that its route computation and packet forwarding mechanisms are poorly integrated with congestion control mechanisms. Any datagram offered to the network is accepted; routers forward packets on a best-effort basis and react to congestion only after the network resources have already been wasted. A number of proposals improve on this to support multimedia applications; a promising example is the Integrated Services Packet Network (ISPN) architecture. However, these proposals are oriented to networks with fairly static topologies and rely on the same conventional Internet routing protocols to operate. This paper presents a routing architecture for mobile integrated services networks in which network nodes (routers) can move constantly while providing end-to-end performance guarantees. In the proposed connectionless routing architecture, packets are individually routed towards their destinations on a hop by hop basis. A packet intended for a given destination is allowed to enter the network if and only if there is at least one path of routers with enough resources to ensure its delivery within a finite time. Once a packet is accepted into the network, it is delivered to its destination, unless resource failures prevent it. Each router reserves resources for each active destination, rather than for each source–destination session, and forwards a received packet along one of multiple loop-free paths towards the destination. The resources and available paths for each destination are updated to adapt to congestion and topology changes. This mechanism could be extended to aggregate dissimilar flows as well. This revised version was published online in June 2006 with corrections to the Cover Date.     

UVoD: An unified architecture for video-on-demand services

Existing video-on-demand (VoD) systems can be classified into two categories: true-VoD (TVoD) and near-VoD (NVoD). TVoD systems allocate a dedicated channel for every user to achieve short latency. NVoD systems make use of multicast technologies to enable multiple users to share a single channel to reduce system cost. This paper proposes a VoD architecture called UVoD that unifies the existing TVoD and NVoD architectures by integrating unicast with multicast transmissions. A performance model of the system is derived and numerical results show that one can achieve significant performance gain over TVoD (over 500%) under the same latency constraints     

A unified wireless LAN architecture for real-time and non-real-timecommunication services

This paper addresses how to support both real-time and non-real-time communication services in a wireless LAN with dynamic time-division duplexed (D-TDD) transmission. With D-TDD, a frequency channel is time-shared for both downlink and uplink transmissions under the dynamic access control of the base station. The base station (1) handles uplink transmissions by polling mobiles in a certain order determined on a per-connection (per-message) basis for transmitting real-time (non-real-time) traffic from mobiles and (2) schedules the transmission of downlink packets. To handle location-dependent, time-varying, and bursty errors, we adopt the channel-state prediction, transmission deferment, and retransmission. We consider the problems of scheduling and multiplexing downlink packet transmissions, and polling mobiles for uplink transmissions depending on the channel state. We also establish conditions necessary to admit each new real-time connection by checking if the connection's delivery-delay bound can be guaranteed as long as the channel stays in good condition without compromising any of the existing guarantees. Last, the performance of the proposed protocol is evaluated to demonstrate how the protocol works and to study the effects of various parameters of the protocol     

Integration of Internet and telecommunications: an architecture forhybrid services

We propose an architecture for hybrid services, i.e., services that span many network technologies, such as the public switched telephone network (PSTN), cellular networks, and networks based on IP. These services will play an important role in the future because they leverage on the existing infrastructures rather than requiring new and sophisticated mechanisms to be deployed. We explore a few issues related to hybrid services and propose a platform as well as a set of components to facilitate their creation and deployment. The existing infrastructure is only required to generate specific events when requests for hybrid services are detected. We present the design of a service layer, based on Java, that handles the treatment of these special requests. Our service layer is provided with a set of generic components realized according to the JavaBeans model. We illustrate the strength of our architecture by discussing two hybrid-service examples: a calendar service and a call forwarding service     

Generic signaling protocol: architecture, model, and services

The functional architecture, connection model, and services of the generic signaling protocol (GSP) are described. GSP is a simple, yet powerful, connection management protocol for ISDN. The semantics and structure of GSP support call suspension and resumption, symmetric and asymmetric bridging, third-party `proxy' call setup, and multiple-connection multimedia calling. GSP can function as a network access, interswitch, computer-to-switch, or network configuration protocol, and it has applications in circuit-switching and packet-switching networks. An example message flow demonstrating how GSP can be used to perform third-party call setup is provided