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1.
Wireless communications have developed rapidly and have been applied for many services. Cellular (the third-generation) mobile networks and wireless local area network (WLAN) are two important technologies for providing wireless communications. The third-generation (3G) networks provide wider service areas, and “always-o” and ubiquitous connectivity with low-speed data rate. WLAN networks offer higher data rate and the easy compatibility of wired Internet, but cover smaller areas. In fact, 3G and WLAN possess complementary properties. Integrating 3G and WLAN networks may offer subscribers high-speed wireless data services and ubiquitous connectivity. For integrating two heterogeneous networks, several issues should be involved, authentication, billing, quality of service, and seamless roaming between 3G and WLAN networks. In this paper, we address the authentication and billing problems and propose two protocols that provide both authentication and billing services. One protocol utilizes a one-time password approach to authenticate subscribers. This protocol is efficient in both computation time and authentication procedures. Because of the restrictions of the password-based approach, this protocol could not offer the non-repudiation property for the billing problem. Another protocol is constructed on a public-key-based system (i.e., certificates). Although it requires more computation time than the password-based approach, non-repudiation is guaranteed. Performance analysis simulation results are given to validate our two protocols.  相似文献   

2.
Mobile communications has seen an explosive growth in the past five years with the integration of communications devices and multimedia applications. Transport connections set up over wireless links are frequently plagued by such problems as a high bit error rate (BER), frequent disconnections of the mobile users, and low wireless bandwidth that may change dynamically. Proposed developments in B3G and 4G wireless services will further challenge researchers to come up with efficient devices that can handle the huge data transmission. Fast and low-power compression algorithms are greatly needed to accommodate the specification. This paper highlights and analyzes various next-generation image-compression algorithms developed on the basis of image transmission via a wireless channel. In addition, the performance comparisons between the proposed hardware implementations are shown. Two important findings are discovered: First, the high-speed reconfigurable devices called FPSoC are the best hardware implementation. Second, a vector-quantization-based VSPIHT algorithm offers the best solution of parallel processing in efficient hardware architecture. This article serves as a reference point for researchers developing image-compression algorithms for next-generation mobile-communications devices. Published in Russian in Radiotekhnika i Elektronika, 2008, Vol. 53, No. 8, pp. 950–963. The text was submitted by the authors in English.  相似文献   

3.
Services in interworking 3G and WLAN environments   总被引:3,自引:0,他引:3  
Interworking WLANs and 3G mobile networks are expected to provide ubiquitous wireless communications at high data rates and a large variety of services with variable bandwidth and QoS requirements, across a wide range of propagation environments and mobility conditions, using dual mode terminals. The interworking of the two networks is a major step toward a new generation of wireless networks in which other radio technologies are also be integrated. In this article we present possible architectures that enable the interworking of 3G and WLAN networks. We then address the capabilities of various terminal types and describe future services in the interworking environment. Finally, we present market forecasts on terminal and service demand growth.  相似文献   

4.
This paper analyzes the security architectures employed in the interworking model that integrates third-generation (3G) mobile networks and Wireless Local Area Networks (WLANs), materializing Beyond 3G (B3G) networks. Currently, B3G networks are deployed using two different access scenarios (i.e., WLAN Direct Access and WLAN 3GPP IP Access), each of which incorporates a specific security architecture that aims at protecting the involved parties and the data exchanged among them. These architectures consist of various security protocols that provide mutual authentication (i.e., user and network authentication), as well as confidentiality and integrity services to the data sent over the air interface of the deployed WLANs and specific parts of the core network. The strengths and weaknesses of the applied security measures are elaborated on the basis of the security services that they provide. In addition, some operational and performance issues that derives from the application of these measures in B3G networks are outlined. Finally, based on the analysis of the two access scenarios and the security architecture that each one employs, this paper presents a comparison of them, which aims at highlighting the deployment advantages of each scenario and classifying them in terms of: a) security, b) mobility, and c) reliability.  相似文献   

5.
Secure cellular data services have become more popular in the Japanese market. These services are based on 2G/3G cellular networks and are expected to move into the next-generation wireless networks, called Beyond 3G. In the Beyond 3G, wireless communication available at a user's location is selected based on the type of the service. The user downloads an application from one wireless network and executes it on another. Beyond 3G expects core and wireless operators and allows to plug-in new wireless access. A security model that can accommodate these requirements needs to be sufficiently flexible for end users to utilize with ease. In this paper, we explain the Mobile Ethernet architecture for all IP networks in terms of the Beyond 3G. We discuss usage scenario/operator models and identify entities for the security model. We separate a mobile device into a personal identity card (PIC) containing cryptographic information and a wireless communications device that offers security and flexibility. We propose a self-delegation protocol for device authentication and use a delegated credential for unified network- and service-level authentication. We also propose proactive handover authentication using the security context between different types of wireless access, such as Third Generation Partnership Project (3GPP) and WLAN, so that the secure end-to-end communication channels established by service software on the TCP/IP are not terminated. Lastly, we raise security issues regarding the next-generation platform.  相似文献   

6.
Global consensus on the next generation of wireless mobile communications, broadly termed “beyond 3G”, sketches a heterogeneous infrastructure comprising different wireless systems in a complementary manner and vested with reconfiguration capabilities, which support a flexible and dynamic adaptation of the wireless network and its spectrum resources to meet the ever-changing service requirements. For ubiquitous reconfiguration to become a practical capability of mobile communication systems, it is necessary to establish a global architecture for modeling, expressing, and circulating essential metadata related to reconfiguration, including reconfigurable device capabilities and semantic properties of protocol stacks. We outline the relevant standardization initiatives in the mobile domain, summarize existing work in reconfiguration-supporting architectures, and identify key shortcomings that may hinder the advent of ubiquitously reconfigurable systems. Further on, we point out some major limitations of current metadata standards in the mobile domain for the representation of capability information pertaining to reconfigurable protocol stacks. Next, we identify essential metadata classes in support of reconfigurable communication systems, introducing an associated object-oriented UML model. We elaborate on the design rationale of the UML model, presenting and discussing the alternative metadata representation standards and suitable encoding formats. Finally, we demonstrate the suitability of our UML model by applying our reconfiguration-supporting vocabulary in the cases of a standardized protocol stack of 3G mobile devices and stationary 3G cellular network elements. Vangelis Gazis received his B.Sc. and M.Sc. (Communication Networking) degrees from the Department of Informatics & Telecommunications of the University of Athens, Greece, in 1995, and 1998, respectively. He also received an M.B.A. degree from the Athens University of Economics and Business in 2001. Since 1996 until, he has been with the research staff of the Communication Networks Laboratory (CNL) of the University of Athens. He has participated in national and European research projects (MOBIVAS, ANWIRE) of the IST framework programme. He specializes in reconfigurable mobile systems and networks for beyond 3G, metadata and ontology languages, reflective and component middleware, adaptable services and open API frameworks for telecommunications. He is currently a Ph.D. candidate in the Department of Informatics & Telecommunications of the University of Athens. Nancy Alonistioti holds a B.Sc. degree and a Ph.D. degree in informatics and telecommunications from the University of Athens. Presently, she is a senior researcher in the Department of Informatics and Telecommunications of the University of Athens. In the past, she has held a research position with the Institute of Informatics and Telecommunications of NCSR “Demokritos” in the areas of protocol and service design and testing, mobile systems (UMTS), open architectures, and software defined radio systems and networks. Her current research interests are in reconfigurable mobile systems and networks beyond 3G, and adaptable services, pervasive computing and context awareness. She has participated in several national and European R&D projects, and has been the technical manager of the IST-MOBIVAS and IST-ANWIRE projects, which have had a focus on reconfigurable mobile systems, networks an respective service provision. She is currently a member of the management team and workpackage leader in the FP6 IST-E2R project on reconfigurability; she also serves as technical manager for the University of Athens in the FP6 IST-LIAISON project, which focuses on location based services in working environments. Dr Alonistioti is co-editor and co-author of the book entitled “Software defined radio, Architectures, Systems and Functions”, published by John Wiley in May 2003. She has authored over 55 publications in the area of mobile communications and reconfigurable systems and networks. Lazaros Merakos received the Diploma in electrical and mechanical engineering from the National Technical University of Athens, Athens, Greece, in 1978, and the M.S. and Ph.D. degrees in electrical engineering from the State University of New York, Buffalo, in 1981 and 1984, respectively. From 1983 to 1986, he was on the faculty of the Electrical Engineering and Computer Science Department, University of Connecticut, Storrs. From 1986 to 1994, he was on the faculty of the Electrical and Computer Engineering Department, Northeastern University, Boston, MA. During the period 1993D1994, he served as Director of the Communications and Digital Processing Research Center, Northeastern University. During the summers of 1990 and 1991, he was a Visiting Scientist at the IBM T. J. Watson Research Center, Yorktown Heights, NY. In 1994, he joined the faculty of the University of Athens, Athens, Greece, where he is presently a Professor in the Department of Informatics and Telecommunications, and Director of the Communication Networks Laboratory (UoA-CNL) and the Networks Operations and Management Center. Since 1995, he is leading the research activities of UoA-CNL in the area of mobile communications, in the framework of the Advanced Communication Technologies and Services (ACTS) and Information Society Technologies (IST) programs funded by the European Union (projects RAINBOW, Magic WAND, WINE, MOBIVAS, POLOS, ANWIRE, E2R, LIAISON). His research interests are in the design and performance analysis of communication networks, and wireless/mobile communication systems and services. He has authored more than 190 papers in the above areas. Dr. Merakos is Chairman of the Board of the Greek Universities Network, the Greek Schools Network, and Member of the Board of the Greek Research Network. In 1994, he received the Guanella Award for the Best Paper presented at the International Zurich Seminar on Mobile Communications.  相似文献   

7.
Due to the introduction of telecommunication technologies in telemedicine services, the expeditious development of wireless and mobile networks has stimulated wide applications of mobile electronic healthcare systems. However, security is an essential system requirement since many patients have privacy concerns when it comes to releasing their personal information over the open wireless channels. For this reason, this study discusses the characteristics and security issues with wireless and pervasive data communications for a ubiquitous and mobile healthcare system which consists of a number of mobile devices and sensors attached to a patient. These devices form a mobile ad hoc sensor network and collect data that are sent to a hospital or healthcare center for monitoring. Subsequently, this paper discusses the innovation and design of a novel trust evaluation model. We then propose a secure multicast strategy that employs trust in order to evaluate the behavior of each node, so that only trustworthy nodes are allowed to participate in communications, while the misbehavior of malicious nodes is effectively prevented. We analyze the security properties of our multicast scheme and evaluate its performance based on simulation experiments. Our experimental results demonstrate that our scheme not only achieves the necessary data transmission in mobile environments, but also provides more security with reasonably little additional overhead.  相似文献   

8.
现代移动通信中无线信道的随机性、不确定性和不可控性是影响通信质量的关键因素,往往会导致接收端信号质量降低,从而限制了信息传输的速率与范围。目前正兴起的6G技术研究中,智能超表面是被积极讨论的研究方向之一,其是由亚波长结构组成的超薄人工表面,具有现场可编程能力和时空信息调制能力,可精准、高效地操控电磁波,可被用于重塑无线传播环境。通过对智能超表面的概念、基于时空调制的波束调控方法、基于智能超表面的无线中继以及通信系统 4 个方面的综述和分析,展示了智能超表面在辅助移动通信中具有的应用潜力,为6G的发展提供了新的思路。  相似文献   

9.
通过将3G移动通信技术应用于智能交通指挥控制系统,并利用发展迅速的3G移动通信网组成3G无线局域网来传输各交通路口信号点的视频和控制信息,为智能交通指挥系统组网提供了一条新路。  相似文献   

10.
黄超 《通信技术》2011,44(3):90-92
第三代移动通信系统(3G)全球范围内有广泛的应用,因此,为了保证3G通信网络安全有序地运行,有必要深入研究3G通信网络的安全机制;在阐述了信息安全理论基础上,设计了3G通信网络的安全体系结构,然后对网络接入安全机制进行了重点分析,最后重点介绍了第三代移动通信系统的认证与协商机制;这种安全机制在实践中的大量应用表明这里分析的3G通信网络安全机制有效、可行。  相似文献   

11.
2009年初,科技部发布了《关于组织“新一代宽带无线移动通信网”国家科技重大专项2009年度TD-SCDMA研发与产业化项目新增课题申报的通知》。随着中国联通、中国移动3G业务的展开,宽带无线移动通信技术在我国有了大范围的应用,后3G时代的宽带无线移动通信中的安全问题,成为研究的热点。论文回顾了无线移动通信的发展历史,分析了无线移动通信、3G演进过程中可能出现的安全问题及其商用密码解决方案。  相似文献   

12.
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.  相似文献   

13.
Bandwidth-efficient wireless multimedia communications   总被引:1,自引:0,他引:1  
Commencing with a brief history of mobile communications and the portrayal of the basic concept of wireless multimedia communications, the implications of Shannon's theorems regarding joint source and channel coding for wireless communications are addressed. Following a brief introduction to speech, video, and graphical source coding as well as the cellular concept, a rudimentary overview of flexible, reconfigurable, mobile radio schemes is provided. We then summarize the fundamental concepts of modulation, introduce an adaptive modem scheme, and argue that third-generation transceivers might become adaptively reconfigurable under network control in order to meet backward compatibility requirements with existing systems and to achieve best compromise among a range of conflicting system requirements, complexity and power consumption, robustness against channel errors, etc  相似文献   

14.
Recently, more and more people have begun using mobile devices such as PDAs and notebooks. Our lives have been profoundly affected by such devices. A MANET, a mobile ad hoc network, is an effective networking system facilitating an exchange data between mobile devices, without the support of wireless access points and base stations. A MANET is not restricted to unicast or multicast communication, but can also provide "many-to-many" transmission, which can be treated as a group communication. Until recently, however, the way in which such groups are formed had not drawn much attention. Because communication in wireless networks is broadcast and a certain amount of devices can receive transmitted messages, the risk of unsecured sensitive information being intercepted by unintended recipients is a real concern. Consequently, efforts to ensure the security of group communications in MANETs are essential. This article proposes a virtual subnet model to construct secure group communication over a MANET. With the model, the composition of groups is established as the forming of group keys. Our results show that this approach can completely satisfy the needs for both security and efficiency.  相似文献   

15.
Wireless Networks - The evolving Fifth generation (5G) cellular wireless networks are envisioned to provide higher data rates, lower end-to-end latency, and lower energy consumption for devices. In...  相似文献   

16.
Wireless mobile communications at the start of the 21st century   总被引:8,自引:0,他引:8  
At the start of the 21st century, the wireless mobile markets are witnessing unprecedented growth fueled by an information explosion and a technology revolution. In the radio frequency arena, the trend is to move from narrowband to wideband with a family of standards tailored to a variety of application needs. Many enabling technologies including wideband code-division multiple access, software-defined radio, intelligent antennas, and digital processing devices are greatly improving the spectral efficiency of third-generation systems. In the mobile network area, the trend is to move from traditional circuit-switched systems to packet-switched programmable networks that integrate both voice and packet services, and eventually evolve toward an all-IP network. Furthermore, accompanied by wireless mobile location technology, wireless mobile Internet is expected to revolutionize the services that can be provided to consumers in the right place and at the right time. Wireless mobile communications may not only complement the well established wireline network; it may also become a serious competitor in years to come. We review the history of the wireless mobile communications, examine the current progress in standards and technologies, and discuss possible trends for wireless mobile solutions  相似文献   

17.
18.
本文针对当前3G尤其是TD—SCDMA移动通信网络建设的需求背景,分析了TD—SCDMA网络与GSM网络分布系统的差异,指出了当前应用中的室内分布覆盖技术在3G网络建设中存在的主要问题,分别从性能和应用方面简要介绍了特别适用于3G网络分布覆盖建设的无线光纤分布系统(WFDS),同时,给出了WFDS在移动通信网络建设中的几个典型试点应用案例简介。  相似文献   

19.
Wireless Technology is growing at an alarming rate with increased security being the main challenge for developers and end users. This study presents after tackling initial challenges and issues faced during the implementation of wireless technology, how security issues and wireless application were implemented at Sydney Airport – a highly mobile organization. The decision to deploy and manage the wireless spectrum throughout the Airport campus meant the wireless LAN will be a shared medium with public users, tenants and aircraft communications, sharing the same available bandwidth. Therefore to protect unintended users from breach of existing security policies adopted by their corporate network a comprehensive security solution needed to be established. This study focuses on how Sydney Airport undertook the WLAN architecture and security challenges of implementing a common use wireless infrastructure. Authentication and data privacy challenges are also presented. The complete WLAN connectivity for tenants, public and corporate usage is presented.  相似文献   

20.
Wireless telemedicine is a new and evolving area in telemedical and telecare systems. Healthcare personnel require realtime access to accurate patient data, including clinical histories, treatments, medication, tests, laboratory results and insurance information. With large-scale wireless networks and mobile computing solutions, such as cellular 3G, Wi-Fi mesh and WiMAX, healthcare personnal can tap into vital information anywhere and at any time within the healthcare networks. The recent introduction of pervasive computing, consisting of radio frequency identification (RFID), Bluetooth, ZigBee, and wireless sensor networks, further extends the potential for exploitation of wireless telecommunications and its integration into new mobile healthcare delivery systems. In this paper, snapshots of current uses and future trends of various wireless communications in the healthcare domain are highlighted. Special attention is given to the challenges of a telemedicine environment equipped with different wireless technologies and how the resulting issues might be addressed in medical services integration to provide flexible, convenient and economical medical monitoring, consultation and healthcare.  相似文献   

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