Balanced association algorithm for IEEE 802.11 extended service areas

Most wireless local area network performance estimations are done with the assumption of uniformly distributed (UD) users. In practice, however, stations (STAs) are distributed unevenly among access points (APs) in an extended service area, causing congested hot‐spots (HS) and under‐utilized APs. Considering a typical network is made up of multiple APs, having some nodes carrying excessive loads degrades the overall network performance. The system performance can be improved by associating STAs efficiently throughout the network, in a sense sharing the network resources fairly among APs and thus relieving congestion. The association algorithm currently employed in IEEE 802.11 systems, that is specifically designed for residential and small office environments, takes into account signal strength as the only parameter and associates STAs to the closest (in signal strength sense) AP, ignoring its load. Novel user association algorithms are required to solve the problems commonly seen in corporate network environments spanning multiple APs, namely congestion relief and resource sharing. In this work, a distributed and online association algorithm is proposed that demonstrates improved average throughput performance, a balanced load distribution as well as fairness across the network compared to the conventional algorithm. Copyright © 2008 John Wiley & Sons, Ltd.     

Protection Management for Guaranteed User‐Driven Virtual Circuit Services in Dynamic Multi‐domain Environments: Design Issues and Challenges

Fault management of virtualized network environments using user‐driven network provisioning systems (NPSs) is crucial for guaranteeing seamless virtual network services irrespective of physical infrastructure impairment. The network service interface (NSI) of the Open Grid Forum reflects the need for a common standard management API for the reservation and provisioning of user‐driven virtual circuits (VCs) across global networks. NSI‐based NPSs (that is, network service agents) can be used to compose user‐driven VCs for mission‐critical applications in a dynamic multi‐domain. In this article, we first attempt to outline the design issues and challenges faced when attempting to provide mission‐critical applications using dynamic VCs with a protection that is both user‐driven and trustworthy in a dynamic multi‐domain environment, to motivate work in this area of research. We also survey representative works that address inter‐domain VC protection and qualitatively evaluate them and current NSI against the issues and challenges.     

A new charging scheme for ATM based on QoS

This paper describes a new approach to charging for ATM called the ‘quality of service (QoS)‐based charging scheme’. In this scheme, traffic resources are distributed among buffers established to support combinations of ATM transfer capabilities and qualities of service. The buffers are dimensioned according to M/D/1/K and ND/D/1 queuing analysis to determine the buffer efficiency and quality of service requirements. This dimensioning provides the basis for fixing the price per unit of resource and time. The actual resource used by a connection is based on the volume of cells transmitted or peak cell rate allocation in combination with traffic shapers if appropriate. Shapers are also dimensioned using the quality of service parameters. Since the buffer efficiency is dependent on the quality of service requirements, customers of ATM networks buy quality of service. The actual price of a connection is also related to the amount of the resource purchased as well as the time of the day at which a connection is made, and the geographical location of the destination switch. The QoS‐based charging scheme meets the requirements of customers and of network operators. Its performance compares very favourably with that of a number of well‐known existing ATM charging schemes. Copyright © 2002 John Wiley & Sons, Ltd.     

Radio resource management schemes for combined GSM/GPRS mobile systems

Data services like Web browsing, e‐mail and file transfer are becoming more and more popular in cellular systems. In contemporary systems like Global System for Mobile communications (GSM), data transfer has been circuit‐switched, that is, physical resources are allocated to a user for the entire call/session duration. However, this is inefficient in case of bursty traffic, where bursts are separated by long intervals of inactivity. This has been the main reason for the introduction of General Packet Radio Service (GPRS), which on the one hand acts as a mobile access network to the Internet, while on the other hand it enables the operator to offer a wide variety of value‐added services [Wireless Access Protocol (WAP) over GPRS, e/m‐banking, e/m‐commerce, push services, etc.] efficiently. However, in contemporary commercial implementations of GPRS the radio resource allocation algorithm does not take into account the Quality of Service (QoS)‐related service characteristics—although such information is exchanged between the terminal and the network—and consequently all service requests are treated the same way (‘best effort’). In this paper, we propose and evaluate via a simulation platform various Radio Resource Management (RRM) schemes capable of differentiating the handling of ‘service requests’ (in uplink and downlink), taking into account the GPRS‐related QoS parameters (precedence, reliability, delay, mean and peak throughput). The evaluation is performed for a range of voice (circuit‐switched) traffic loads, number of Transmit Receive eXchange (TRXs), offered data (packet‐switched) services characteristics, number of dedicated Packet Data Channels (PDCHs), and so on, taking into account the respective QoS requirements for both service types (circuit‐ and packet‐switched). Copyright © 2003 John Wiley & Sons, Ltd.     

The user profile for the virtual home environment

This article addresses user data issues for virtual home environment (VHE) management among heterogeneous networks and service applications. User data represent all information describing the network and personalized service environments related to a roaming user. After analyzing user data accessed by identified VHE functions and roles, a modular and flexible information model called a user profile has been designed. Various architecture scenarios are then addressed for the implementation of this user profile. Among them, the best one fits the needs and constraints due to existing network architectures, and eventually provides a global federating solution for VHE management.     

An IP-based QoS architecture for 4G operator scenarios

This article describes a global QoS architecture for multimedia traffic in mobile heterogeneous environments. This architecture supports both multiple access networks and multiple service provider scenarios. The architecture is able to provide QoS per user and per service, implementing the notion of a user profile associated network management in the case of heterogeneous and mobile network access is presented based on cooperative association between QoS brokers and authentication, authorization, accounting, and charging systems. The overall exchange of messages is exemplified for the case of a field test with specific optimizations for voice traffic.     

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.     

P2P文件共享系统中基于用户行为的搭便车抑制机制

In order to inhibit Free Riding in Peer-to-Peer (P2P) file-sharing systems, the Free Riding In-hibition Mechanism Based on User Behavior (IM-BUB) is proposed. IMBUB considers the regularity of user behavior and models user behavior by ana-lyzing many definitions and formulas. In IMBUB, Bandwidth Allocated Ratio, Incentive Mechanism Based on User Online Time, Double Reward Mech-anism, Incentive Mechanism of Sharing for Permis-sion and Inhibition Mechanism of White-washing Behavior are put forward to inhibit Free Riding and encourage user sharing. A P2P file system BITShare is designed and realized under the conditions of a campus network environment. The test results show that BITShare's Query Hit Ratio has a significant increase from 22% to 99% , and the sharing process in BITShare is very optimistic. Most users opt to use online time to exchange service quality instead of white-washing behavior, and the real white-ish-ing ratio in BITShare is lower than 1% . We confirm that IMBUB can effectively inhibit Free Riding be-havior in P2P file-sharing systems.     

Design and analysis of a bandwidth management framework forATM-based broadband ISDN

When designing and configuring an ATM-based B-ISDN, it remains difficult to guarantee the quality of service (QoS) for different service classes, while still allowing enough statistical sharing of bandwidth so that the network is efficiently utilized. These two goals are often conflicting. Guaranteeing QoS requires traffic isolation, as well as allocation of enough network resources (e.g., buffer space and bandwidth) to each call. However, statistical bandwidth sharing means the network resources should be occupied on demand, leading to less traffic isolation and minimal resource allocation. The authors address this problem by proposing and evaluating a network-wide bandwidth management framework in which an appropriate compromise between the two conflicting goals is achieved. Specifically, the bandwidth management framework consists of a network model and a network-wide bandwidth allocation and sharing strategy. Implementation issues related to the framework are discussed. For real-time applications the authors obtain maximum queuing delay and queue length, which are important in buffer design and VP (virtual path) routing     

The TINA initiative [intelligent networks]

The telecommunications information networking architecture (TINA), which builds on the current advances in broadband communication and distributed computing technologies, specifying a software-based architecture for future information networks that are required to transport multimedia information and manage multimedia communication, is described. An important aspect of the architecture is that service segment functions are separated from delivery segment functions. Another key aspect is the elimination of the rigid division between network applications and operations applications that exists in current-day networks. In the TINA architecture, both kinds of applications execute on a common distributed processing platform that hides from applications the effects and complexities introduced by distribution. The architecture supports application interoperability enabling flexible construction of services, composed of service components distributed across network domains, allowing network operators and service providers to cooperatively meet the needs of the user     

确保通信客户不停机的在线自动充和网络重定向技术研究

面向5G和大连接的发展,阐述了实现通信客户永不停机的在线自动充和网络重定向两大技术。在线自动充基于便捷的第三方支付体系和实时的线上信用体系实现前置不停机;网络重定向基于专属“APN+SAEGW”网元改造和智能页面改造实现后置不停机,保证通信业务的持续性和稳定性,有效提升客户感知。     

基于用户行为认知的在线社交网络协同推荐

近年来,在线社交网络成为人们工作、生活不可或缺的信息共享与交流工具,如何对海量庞杂、大范围时空关联的用户行为信息进行认知并据此提供个性化的推荐服务,已成为在线社交网络发展重点关注的问题。为此,提出了一种基于用户行为认知的在线社交网络协同推荐框架,在对用户特征、文本信息及兴趣偏好等行为进行认知的基础上,利用协同过滤算法,实现个性化的推荐服务。实验结果验证了提出的基于用户行为认知的协同推荐策略具有较好的稳定性和实际应用效果。     

BPR-UserRec:a personalized user recommendation method in social tagging systems

Social tagging is one of the most important characteristics of Web 2.0 services, and social tagging systems (STS) are becoming more and more popular for users to annotate, organize and share items on the Web. Moreover, online social network has been incorporated into social tagging systems. As more and more users tend to interact with real friends on the Web, personalized user recommendation service provided in social tagging systems is very appealing. In this paper, we propose a personalized user recommendation method, and our method handles not only the users’ interest networks, but also the social network information. We empirically show that our method outperforms a state-of-the-art method on real dataset from Last.fm dataset and Douban.     

Maximized achievable rate of SINR‐measurement‐based spectrum sharing with binary feedback

Motivated by the difficulty in measuring channel state information between heterogeneous primary and secondary systems, we propose a signal‐to‐interference‐noise ratio (SINR)‐based spectrum sharing policy. In the proposed spectrum sharing policy, a secondary user who does not cause SINR outage at the primary receiver is admitted to share the primary user's spectrum. In this article, we analyze the achievable rate of a secondary user and for whom the achievable rate is maximized in the SINR‐constrained spectrum sharing. The maximized achievable rate is determined by the ratio of the distance between the secondary transmitter and the primary receiver to the distance between the secondary transmitter and receiver, and it is proportional to the distance ratio. In conclusion, secondary links with large distance ratio can support high data rate applications so long as SINR constraint of the primary user is guaranteed. Copyright © 2011 John Wiley & Sons, Ltd.     

智能网中的安全机制

安全机制是智能网的核心问题之一，也是智能网实现互连的主要问题。本文从智能网所面临的威胁入手，提出了解决问题的策略，可变证码算法，互相认证算法和信息加密算法等，并对这些算法进行了分析和说明。     

A Bayesian approach for user aware peer-to-peer video streaming systems

Peer-to-Peer (P2P) architectures for live video streaming has attracted a significant attention from both academia and industry. P2P design enables end-hosts to relay streams to each other overcoming the scalability issue of centralized architectures. However, these systems struggle to provide a service of comparable quality to that of traditional television. Since end-hosts are controlled by users, their behavior has a strong impact on the performance of P2P streaming systems, leading to potential service disruption and low streaming quality. Thus, considering the user behavior in these systems could bring significant performance improvements. Toward this end, we propose a Bayesian network that captures all the elements making part of the user behavior or related to it. This network is built from the information found in a cross-analysis of numerous large-scale measurement campaigns, analyzing the user behavior in video streaming systems. We validate our model through intensive simulations showing that our model can learn a user behavior and is able to predict several activities helping thus in optimizing these systems for a better performance. We also propose a method based on traces collection of the same user type that accelerates the learning process of this network. Furthermore, we evaluate the performance of this model through exploring its applications and comparison with non-contextual models.     

基于Gy接口的分组域实时计费系统

本文首先分析了分组域离线计费方式在运营中存在的局限性,随后介绍了3GPP基于Gy接口的分组域在线计费的基本原理。然后提出了适用于移动运营商的分组域实时计费系统架构,最后提出了分组域实时计费系统在实际部署中应重点关注的问题,并提出了解决方案。     

梦网业务欠费风险控制系统研究

针对移动通信领域梦网业务的恶意欠费占比日趋严重的现状,本文描述了一种梦网业务欠费风险控制系统的建设方案。实现对用户使用梦网业务进行实时控制,降低BOSS系统预付费业务的用户欠费风险,提高收入保障水平。     

Charging Information Collection Modeling and Analysis of GPRS Networks

Charging is one of the most important functionalities in a telecommunication service system. In a general packet radio service (GPRS) wireless network, the load of charging information flow depends on the intensity of call traffic and the size of charging records. During busy hours, the GPRS network might not be able to transfer charging records on a timely basis if new charging records are generated too fast. On the other hand, when a call happens, the related charging information must be collected and transferred to the billing system. If a failure of the data link occurs, a secondary data link must be employed to transfer the charging information. However, this redundant operation might result in charging information duplication. This paper formally addresses these two issues. A timed Petri net model is built to support the analysis of the charging system performance versus various factors when the system works in the normal status, which, in particular, gives the maximum supportable busy hour call attempts of the GPRS network. The Petri net approach is also used to model and verify the correctness of the redundancy operation in case a connection failure occurs.     

The design and implementation of an extensible, user-management service for communications applications - [topics in design & implentation]

Many network administration organizations, including communication service providers, are faced with the problem of managing a growing number of applications with fewer administrators. Administrators are required to provision and administer application-specific data in order for users (e.g., subscribers) to access and use communication applications. Although there are several approaches for solving the problem of sharing identity data across applications, a general solution for provisioning and sharing the complete user or subscriber profile has not been defined. This article describes the design and implementation of an extensible, user-management service that solves the problem of the redundant data entry required in provisioning and maintaining multiple communication applications. An important aspect of the design is the capability of the user-management service to be extended at run time without requiring an upgrade of the service and without impacting already deployed applications. Key lessons that can be applied to reduce the time and cost for other organizations faced with implementing user- or subscriber-management projects also are described.