Antennas for next generation mobile communications

In future mobile communications many antennas will coexist on the device. This creates a number of problems related to bandwidth, efficiency, and correlation. Remedies are discussed in the paper, and attention is called to the promising area of adaptive matching, which also can solve problems related to the user.     

Perspectives on next generation mobile

Employees in today’s enterprises are requesting their employers to allow them to work in a flexible manner. Work is no longer a place to go to but an activity to be undertaken. With developments in technology, the activity can be undertaken whenever and wherever it is convenient for the employees. Increasing demands by employees to be able to work in this way creates a tension within the enterprise as CIOs and finance officers strive to manage the costs and the infrastructure required to support this way of working. Over time, this situation will change as technology allows users to roam securely and seamlessly between networks accessing the required applications and information from a single suitably enabled device. This will tend to reduce the underlying costs as the best connection can be used. Service management will remain a challenge but become a better understood problem as the ’stove-pipe’ nature of current solutions is removed. For this change to be brought about, some enabling technologies have to be put in place. This paper considers issues surrounding next generation mobile solutions and shows how converged services can be used to deliver the vision of being able to work from any place, at any time. Consideration is given to how roaming from fixed to wireless networks can be achieved by reusing already established authentication principles that are now deployed in wide area wireless networks. In order to do this, open methods of managing user identity need to be devised and implemented and approaches to this are also discussed. The paper concludes with a consideration of some of the research challenges that remain to be solved. HP     

IIDWBA algorithm for integrated hybrid PON with wireless technologies for next generation broadband access networks

Optical and wireless technology integration has been proposed as one of the most promising nominees for the next-generation broadband access networks for quite some time. Integration scheme merges the high-speed and high-capacity of the optical networks with the low-cost, wide-coverage and mobility features of the wireless counterparts for the Subscriber Stations (SSs). It is also financially viable for the telecommunication service providers, particularly in the rural area where the development of optical infrastructure or expansion of the existing telecommunication solutions such as Digital Subscriber Line (DSL), Cable Modem (CM) or T-1/E-1 networks are either too costly or unreachable. In order to successfully integrate the two technologies, there are some technical concerns in terms of Architectural aspects, Physical Layer features and Media Access Control (MAC) related issues, which need to be addressed efficiently in order to provide the smooth end-to-end (e2e) integration. This paper is mainly focused upon the analysis of the key topics in MAC-related issues such as E2E wavelength/bandwidth requests and allocations over the converged scenario. It proposes an Inter-channel and Intra-channel Dynamic Wavelength/Bandwidth Allocation (IIDWBA) algorithm where the hybrid Passive Optical Network (PON) acts as a back haul technology for the wireless counterpart. The proposed algorithm works in three phases, namely, Initialisation, Intra-channel bandwidth allocations and Inter-channel bandwidth allocations and is capable of allocating wavelength/bandwidth efficiently and effectively over the converged scenario. Performance of the proposed algorithm is evaluated through conducted simulation scenarios under different simulation parameters, traffic patterns and load values. According to the captured results, IIDWBA algorithm shows a better performance when it is compared to the scenario in which it has not been employed.     

下一代手机用电源管理芯片

10多年前,当第一代蜂窝电话出现时,采用了许多分立功率器件.第一代手机显得很笨重,高功耗使得待机时间和通话时间都很短.为了响应客户对外形更小,性能更高的无线电子设备不断增长的需求,工程师发展了许多先进的设计技术.这些技术既可缩小印刷电路板(PCB)尺寸,又可以提供更快更高效的性能.     

面向新一代移动通信的智能天线技术

第三代移动通信系统,最重要的技术特征将是智能移动通信技术,即系统的各功能模块将由智能化处理单元来实现,作为智能化处理单元重要组成部分的智能天线,其在新一代移动通信系统中的开发和应用研究已成为当今移动通信界的热点。本文就其技术思想、研究成果及现有水平进行了讨论,并就其进一步的发展进行了简要论述。     

下一代无线接入基础设施的混合接口解决方案

宽带无线通信将会彻底改变人们生活的每一方面。它直接提供了到人们所需信息的高速连接,无论是在何时何地。新的无线技术,如WiMAX（微波存取全球互通）,允许服务供应商们在工业化国家和发展中国家内发展新的业务板块、触及新业务和新的个人用户。     

UMTS the next generation of mobile radio

Europe's third-generation mobile communication system will transform the capabilities of cellular networks. The authors describe some of the implications for users, network operators and would-be licence holders of UMTS (Universal Mobile Telephone System)     

Traffic aware cell selection algorithm for Tetra Trunk based professional mobile radio

Telecommunication Systems -     

UPTIME: an IMS-based mobility framework for next generation mobile networks

Seamless inter-technology mobility is one of the fundamental requirements of next generation mobile networks. For seamless mobility, handover delay and packet loss should be minimized. However, existing solutions suffer from a number of shortcomings in satisfying these requirements: first, handover preparation schemes fail to minimize the handover delay as much as possible. Second, minimizing packet loss which is usually using soft handover (SHO) schemes are excessively wasteful of scarce resources. In this paper, we propose the uninterrupted proactive connection transfer for IMS mobility enhancement (UPTIME) mobility framework which achieves seamless mobility while minimizing excessive power and radio resource consumption. UPTIME incorporates two mechanisms; a proactive handover preparation method and an optimized SHO technique for handover execution. We demonstrate the benefits of the proposed framework through both analysis and simulation. Our simulation results for typical LTE/WiMAX handovers show that the handover preparation delay can be reduced by 70 %, and good packet loss performance can be achieved whilst saving 43 % of radio resources and 48 % of battery power.     

A window random access algorithm for environments with capture

The authors propose and analyze a stable random access algorithm which is a modification of the two-cell algorithm proposed by M. Paterakis (1984). The authors assume ternary feedback broadcast per slot, and in the presence of capture, identification of the captured packet by all the users in the system. It is also assumed that a successfully received signal transmission cannot be distinguished from a capture in the presence of multiple transmission. The performance of the algorithm is compared to an appropriate modification of J.I Capetanakis' (1979) dynamic algorithm. The proposed algorithm, and in contrast to the latter, it can be easily modified to operate in limited feedback sensing environments     

Network-centric user assignment in the next generation mobile networks

This letter addresses the user assignment problem for multimedia streaming applications in heterogeneous multicast-enabled wireless networks using a network-centric strategy. The optimal problem is mathematically formulated and proven to be non-deterministic polynomial-time (NP)-hard. An efficient heuristic algorithm is then proposed to find sub-optimal solutions in practical systems. Simulation results demonstrate the improved performance of this heuristic in comparison to a conventional user-centric algorithm     

On designing issues of the next generation mobile network

Next generation mobile network (NGMN) is envisaged to support seamless mobility across disparate access technologies in a transparent manner. The success of NGMN design will depend on its ability to address key design issues, mainly architectural adaptation and modification of service continuity functions (i.e., mobility and resource management) that arise from such interoperability. The solutions presented in this article attempt to resolve these issues by considering an IP-based interworking framework that promotes evolution of individual networks and integration of new technologies     

Performance analysis of next generation web access via satellite

Responsiveness is a critical metric for web performance. Recent work in the Internet Engineering Task Force (IETF) and World Wide Web Consortium (W3C) has resulted in a new set of web protocols, including definition of the hypertext transfer protocol version 2 (HTTP/2) and a corresponding set of TCP updates. Together, these have been designed to reduce the web page download latency compared with HTTP/1.1. This paper describes the main features of the new protocols and discusses the impact of path delay on their expected performance. It then presents a set of tests to evaluate whether current implementations of the new protocols can offer benefit with an operational satellite access network and suggests how the specifications can evolve and be tuned to further enhance performance for long network paths. Copyright © 2016 John Wiley & Sons, Ltd.     

EPON:下一代宽带光接入网

介绍了EPON（以太网无源光网络）的体系结构，国内外的研究现状以及市场和应用，并对其前景进行了展望。     

Pervasive data access in wireless and mobile computing environments

The rapid advance of wireless and portable computing technology has brought a lot of research interests and momentum to the area of mobile computing. One of the research focus is on pervasive data access. With wireless connections, users can access information at any place at any time. However, various constraints such as limited client capability, limited bandwidth, weak connectivity, and client mobility impose many challenging technical issues. In the past years, tremendous research efforts have been put forth to address the issues related to pervasive data access. A number of interesting research results were reported in the literature. This survey paper reviews important works in two important dimensions of pervasive data access: data broadcast and client caching. In addition, data access techniques aiming at various application requirements (such as time, location, semantics and reliability) are covered. Copyright © 2006 John Wiley & Sons, Ltd.     

下一代无线移动通信LTE及LTE-Advanced的研究

长期演进项目(LTE)是第三代移动通信合作伙伴项目(3GPP)为下一代无线移动通信最新制定的一项标准.重点研究了LTE的关键技术,并且详细分析了3GPP定位于满足ITU提出的IMT-Advanced的LTE-Advanced标准,包括它的发展历程、演进目标、技术指标以及新的关键技术.     

Discovering the architecture of geo-located web services for next generation mobile networks

As many geo-located Web services will be deployed in the future, mobile clients will be interested in locating a specific application server based on requirements such as proximity, service cost per location area, bandwidth, and server utilization rates. This paper presents a middleware system called GLWSA (Geo-Located Web Services Architecture) that aims to satisfy these requirements in addition to providing a thematic factorization of common location functions in order to locate mobile clients. The GLWSA supports a set of GLWSMs (Geo-Located Web Services Manager) distributed over the mobile network. It defines protocols to discover and inform a Supplier Application Server (SAS) to migrate the service execution (from a specific client) to the nearest SAS based on the client's location. This architecture is suitable to assist mobile clients to discover the geo-located Web services and to maintain the service execution closest to their location.