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1.
Wireless Personal Communications - Multipath data transfer enables a network host to send its data stream via multiple different network paths at the same time. In this research, we propose a novel...  相似文献   

2.
WiMAX is a wireless metropolitan area network (WMAN) specified by IEEE 802.16. It provides the broadband wireless access for mobile devices. In such a system, to enable the mobility, the handover is supported to maintain the connectivity of the mobile station (MS) when it moves from the coverage of the serving base station (BS) to the coverage of a neighbor BS. In the handover process, scanning is required to find a suitable target BS, and network re-entry is needed to establish the new connection. However, in the standard handover process, a long latency to data transmissions is caused resulting in the serious interruption to ongoing services. In this paper, an improved handover scheme is proposed to reduce the latency introduced in the handover process by shortening the scanning and enhancing the network re-entry. The proposed scanning strategy reduces the latency by reducing the number of neighbor BSs to be scanned through estimating the rough location of the MS. The enhanced network re-entry reduces the delay by updating transport connection identifiers (CIDs) early to allow the fast resumption of active applications. Simulations were conducted to evaluate the performance of the proposed handover scheme. The results show that the proposed handover scheme reduces the data transmission latency during handover significantly.  相似文献   

3.
Recent advances in hardware technology have made it possible for mobile devices to interface with multiple networks of different types. In this paper, an IEEE 802.21 Media Independent Handover (MIH) based handover management architecture containing four modules is proposed and the multihoming technology is adopted to achieve Make-Before-Break vertical handover. Then the paper presents the performance analysis of the architecture and simulation in ns-2. The results substantiate the effi cacy of the architecture in improving the handover performance signifi cantly compared with the traditional Mobile IPv6 (MIPv6) based vertical handover. Besides, we design and implement this handover management architecture in our test-bed. The experimental results in a real network environment show that our proposed architecture can not only support the Make-before-break handover, but also guarantee the scalability because of the modulized design.  相似文献   

4.
This paper presents a Computational Memory architecture for MPEG-4 applications with mobile devices. The proposed architecture is used for real-time block-based motion estimation, which is the most computational intensive task in the video encoder. It uses the exhaustive block-matching algorithm (EBMA) for motion estimation. The proposed architecture consists of embedded SRAMs and a number of block-matching units working in parallel to process video data while stored in the memory. The block-matching units access the embedded SRAMs simultaneously, which increases the speed of the architecture. The architecture processes CIF format video sequences (i.e., the frame size is 352 × 288 pixels) with block size of 16 × 16 pixels and ±15 pixels search range. The proposed architecture has been designed, prototyped, and simulated for 0.18 μm TSMC CMOS technology. The simulation shows that the proposed architectures processes up to 126 CIF frames per second with clock frequency 100 MHz. The synthesized prototype of the proposed architecture includes 200 KB memory and it has an area of 33.75 mm2 and consumes 986.96 mW @100 MHz. Mohammed Sayed received his B.Sc. degree from Zagazig University, Zagazig, Egypt, in 1997 and a postgraduate diploma in VLSI design from the Information Technology Institute (ITI), Cairo, Egypt, in 1998. In 2003 he received his M.Sc. degree from University of Calgary, Calgary, Canada. From 1998 to 2001 he was a research and teaching assistant at the Electronics & Communications Engineering Department, Zagazig University, Egypt. In 2001 he became a research assistant at the Department of Electrical and Computer Engineering, University of Calgary, Canada. His current research interests are System-on-Chip, Embedded Memories, and Digital Video Processing. Mr. Sayed received a number of scholarships and awards such as iCORE Scholarship from 2003 to 2005, SMC Industrial Collaboration Award in June 2003, and the Micronet Annual Workshop Best Paper Award in April 2002. He has a number of journal and conference publications and a number of contributions to the MPEG-4 standard (ISO/IEC JTC1/SC29/WG11 MPEG2002/ M8562 and M8563). Wael Badawy is an associate professor in the Department of Electrical and Computer Engineering. He holds an adjunct professor in the Department of Mechanical Engineering, University of Alberta. Dr. Badawy's research interests are in the areas of: Microelectronics, VLSI architectures for video applications with low-bit rate applications, digital video processing, low power design methodologies, and VLSI prototyping. His research involves designing new models, techniques, algorithms, architectures and low power prototype for novel system and consumer products. Dr. Badawy authored and co-authored more than 100 peer reviewed Journal and Conference papers and about 30 technical reports. He is the Guest Editor for the special issue on System on Chip for Real-Time Applications in the Canadian Journal on Electrical and Computer Engineering, the Technical Chair for the 2002 International Workshop on SoC for real-time applications, and a technical reviewer in several IEEE journals and conferences. He is currently a member of the IEEE-CAS Technical Committee on Communication. Dr. Badawy was honored with the “2002 Petro Canada Young Innovator Award”, “2001 Micralyne Microsystems Design Award” and the 1998 Upsilon Pi Epsilon Honor Society and IEEE Computer Society Award for Academic Excellence in Computer Disciplines. He is currently the Chairman of the Canadian Advisor Committee (CAC) and Head of the Canadian Delegation on ISO/IEC/JTC1/SC6 “Telecommunications and Information Exchange Between Systems”. Member, The Canadian Advisory Committee for the Standards Council of Canada—Subcommittee 29: Coding of Audio, Picture Multimedia and Hypermedia Information, and Canadian Delegate, The ISO/IEC MPEG standard committee. He is a voting Member on the VSI Alliance. He is also the Chair of the IEEE-Southern Alberta Society-Computer Chapter.  相似文献   

5.
贡越  程时昕 《电子学报》1997,25(11):49-53
本文提出了一种支持大型大学校园中移动通信的网络结构,设计允许每个移动宿主机在校园中自由漫游时保持传输连接性。设计结合了无线局域网和高速异步转移模式交换技术,提供了一个有处理大量移动宿主同时运动的有充足集合带宽的无线通信系统。  相似文献   

6.
从五个不同方面对移动通信网络的演进路线进行阐述,重点对无线通信关键技术、移动通信网络架构、网络设备形态、异构网络融合及移动终端的主要演进趋势进行分析,同时,以运营商的视角指出移动通信网络的演进需要兼顾现有网络站址及设备资源,应以优化网络资源配置、简化网络结构和便于网络运营及治理为主要目的。  相似文献   

7.
在研究移动无线传感器网络特性的基础上,借鉴蒙特卡洛算法思想,提出一种利用移动无线传感器网络特性进行定位的算法(EFL).EFL算法把移动无线传感器网络的移动特性和低秩特性作为节点定位的约束条件以提高节点定位的精度.仿真结果表明,采用EFI算法,节点的定位精度有较大提高.  相似文献   

8.
电子百科     
码分多址(CDMA);蜂窝式移动电话系统;手机TV-OUT;  相似文献   

9.
Network security for mobile devices is in high demand because of the increasing virus count. Since mobile devices have limited CPU power, dedicated hardware is essential to provide sufficient virus detection performance. A TCAM-based virus-detection unit provides high throughput, but also challenges for low power and low cost. In this paper, an adaptively dividable dual-port BiTCAM (unifying binary and ternary CAMs) is proposed to achieve a high-throughput, low-power, and low-cost virus-detection processor for mobile devices. The proposed dual-port BiTCAM is realized with the dual-port AND-type match-line scheme which is composed of dual-port dynamic AND gates. The dual-port designs reduce power consumption and increase storage efficiency due to shared storage spaces. In addition, the dividable BiTCAM provides high flexibility for regularly updating the virus-database. The BiTCAM achieves a 48% power reduction and a 40% transistor count reduction compared with the design using a conventional single-port TCAM. The implemented 0.13 mum processor performs up to 3 Gbps virus detection with an energy consumption of 0.44 fJ/pattern-byte/scan at peak throughput.  相似文献   

10.
每月新品     
MCU/DSP/CPU英特尔至强处理器5400系列/双核英特尔至强处理器5200系列英特尔宣布推出面向嵌入式市场的全新处理器(具有长达7年的生命周期支持)、芯片组及电信级服务器。新款处理器基于高k金属栅极晶体管技术,并采用先进的45nm制程工艺,具体产品包括四核英特尔至强处理器5400系列和双核英特尔至强处理器5200系列。  相似文献   

11.

Intrusion Detection System (IDS) is crucial to protect smartphones from imminent security breaches and ensure user privacy. Android is the most popular mobile Operating System (OS), holding above 85% market share. The traffic generated by smartphones is expected to exceed the one generated by personal computers by 2021. Consequently, this prevalent mobile OS will stay one of the most attractive targets for potential attacks on fifth generation mobile networks (5G). Although Android malware detection has received considerable attention, offered solutions mostly rely on performing resource intensive analysis on a server, assuming a continuous connection between the device and the server, or on employing supervised Machine Learning (ML) algorithms for profiling the malware’s behaviour, which essentially require a training dataset consisting of thousands of examples from both benign and malicious profiles. However, in practice, collecting malicious examples is tedious since it entails infecting the device and collecting thousands of samples in order to characterise the malware’s behaviour and the labelling has to be done manually. In this paper, we propose a novel Host-based IDS (HIDS) incorporating statistical and semi-supervised ML algorithms. The advantage of our proposed IDS is two folds. First, it is wholly autonomous and runs on the mobile device, without needing any connection to a server. Second, it requires only benign examples for tuning, with potentially a few malicious ones. The evaluation results show that the proposed IDS achieves a very promising accuracy of above 0.9983, reaching up to 1.

  相似文献   

12.
Multihomed, mobile wireless computing and communication devices can spontaneously form communities to logically combine and share the bandwidth of each other's wide-area communication links using inverse multiplexing. But, membership in such a community can be highly dynamic, as devices and their associated WWAN links randomly join and leave the community. We identify the issues and trade-offs faced in designing a decentralized inverse multiplexing system in this challenging setting and determine precisely how heterogeneous WWAN links should be characterized and when they should be added to, or deleted from, the shared pool. We then propose methods of choosing the appropriate channels on which to assign newly arriving application flows. Using video traffic as a motivating example, we demonstrate how significant performance gains can be realized by adapting allocation of the shared WWAN channels to specific application requirements. Our simulation and experimentation results show that collaborative bandwidth aggregation systems are, indeed, a practical and compelling means of achieving high-speed Internet access for groups of wireless computing devices beyond the reach of public or private access points  相似文献   

13.
14.
The evolution and the spreading of wireless access technology and the consequent increase of user mobility will make handover procedures critical for the provision of Quality of Service in the next generation wireless Internet. Often, layer 3 handovers are supposed to be driven by access layer procedures. In this way, the movement detection delay can be reduced, but at the expenses of making the Mobile IP protocol dependent of lower layer implementations. Furthermore, this approach may not be effective when users roam among heterogeneous networks. Nevertheless, movement detection algorithms, which operate at the Mobile IP layer, imply appreciable delays, usually intolerable for real time services.In this paper, we propose a Mobile IP handover scheme based on a novel movement detection algorithm at layer 3, able to timely manage migrations by exploiting advertisements losses, combined with a two-timers mechanism.We analyze the performance of our algorithm in terms of handover delay and throughput, and we show that our solution is able to decrease the movement detection delay as much as 47% with respect to other literature solutions that pursue similar approaches. In addition, this feature implies also higher values of the throughput seen by the TCP layer.This work has been carried out in the framework of the FIRB Project PRIMO, co-financed by the Italian Ministry for Education, Higher Education and Research (MIUR).Nicola Blefari Melazzi received his Laurea degree in Electrical Engineering in 1989, magna cum laude with publication of his thesis, and earned the Dottore di Ricerca (Ph.D.) in Information and Communication Engineering in 1994, both at the University of Roma La Sapienza, Italy. In 1993 he joined the University of Roma Tor Vergata, as an Assistant Professor. From 1998 to 2002 he has been an Associate Professor at the University of Perugia. In 2002 he came back to the University of Roma Tor Vergata as a Full Professor of Telecommunications.Dr. Blefari-Melazzi has been involved in consulting activities and research projects, including standardization and performance evaluation work. His research projects have been funded by the Italian Ministry of Education, University and Research, by the Italian National Research Council, by industries, by the European Union and by the European Space Agency. He also reviewed research proposals and research projects.Dr. Blefari-Melazzi served as reviewer, TPC member, session chair and guest-editor to IEEE conferences and journals.His research interests include the performance evaluation, design and control of broadband integrated networks, wireless LANs and satellite networks. He is also conducting research on multimedia traffic modeling, mobile and personal communications, quality of service guarantees and real time services support in the Internet.Mauro Femminella received his Laurea degree in Electronic Engineering in 1999, magna cum laude with publication of his thesis, and earned the Ph.D. degree in Electronic Engineering in 2003, both at the University of Perugia, Italy. He was Consulting Engineer for the University of Perugia, and for the consortia CoRiTel and RadioLabs. Actually he holds a position as contract researcher at the Department of Information and Electronic Engineering at the University of Perugia.He was involved in a number of research projects co-funded by the European Union (programs ACTS and IST), by the Italian Ministry for Education, Higher Education and Research (MIUR), and by the European Space Agency (ESA).He is co-author of a number of papers in international conferences and journals.His research interests focus on design and performance evaluation of satellite networks, content delivery networks, IP quality of service and IP mobility.Fabio Pugini received his laurea degree (M.S.) in Electronic Engineering (magna cum laude) in 2000 from University of Rome La Sapienza. He was with the INFOCOM Dept. of the same University during 2001 and 2002 as Ph.D. student in Computer Science. His main research interests regarded Mobility issues and QoS provision in IP networks. He was consulting engineer for the DIEI Department of the University of Perugia and was involved in the following European Projects: SUITED, WHYLESS.COM, FIFTH. In 2002 he received his M.B.A. degree from University of Rome Tor Vergata. He worked as a system analyst in MBDA Missile Defense Systems and currently he is with McKinsey & Company as a Junior Associate.  相似文献   

15.
本文介绍了如何为移动设备常用的不同处理器供电,以及在便携应用中的处理器专用电源芯片如何在提高效率的同时降低功耗。  相似文献   

16.
Digital Television for Mobile Devices   总被引:1,自引:0,他引:1  
A survey of mobile television technologies analyzes technical characteristics for each mobile TV solution, discusses specifications and standards, and presents possible future developments.  相似文献   

17.
引言 现有的接口技术如低电压差分信号传输(LVDS)、更低摆幅差分信号传输(RSDS)及CMADS虽然仍可满足上一代笔记本计算机的要求,在某种程度上节省用电,减少这类产品的互连线路,并减低其电磁干扰,但对于正在开发中的新一代蜂窝式移动电话及个人数字助理,现有的接口技术便无法满足其要求,因为新一代产品的设计要求更低的功率、更少互连线路以及更低的电磁干扰.  相似文献   

18.
In wireless mobile networks, group mem-bers join and leave the group frequently, a dynamic group key agreement protocol is required to provide a group of users with a shared secret key to achieve cryptographic goal. Most of previous group key agreement protocols for wireless mobile networks are static and employ traditional PKI. This paper presents an ID-based dynamic authen-ticated group key agreement protocol for wireless mobile networks. In Setup and Join algorithms, the protocol re-quires two rounds and each low-power node transmits con-stant size of messages. Furthermore, in Leave algorithm, only one round is required and none of low-power nodes is required to transmit any message, which improves the e?-ciency of the entire protocol. The protocol’s AKE-security with forward secrecy is proved under Decisional bilinear in-verse Di?e-Hellman (DBIDH) assumption. It is addition-ally proved to be contributory.  相似文献   

19.
In recent years, high?resolution video has developed rapidly and widescreen smart devices have become popular. We present an Android application called WeWatch that enables high?resolution video to be ...  相似文献   

20.
Mobile cloud computing combines wireless access service and cloud computing to improve the performance of mobile applications. Mobile cloud computing can balance the application distribution between the mobile device and the cloud, in order to achieve faster interactions, battery savings and better resource utilization. To support mobile cloud computing, the paper proposes a phased scheduling model of mobile cloud such that mobile device’s users experience lower interaction times and extended battery life. The phased scheduling optimization is solved by two subproblems: mobile device’s batch application optimization and mobile device’s job level optimization. At the first stage, the mobile cloud global scheduling optimization implements the allocation of the cloud resources to the mobile device’s batch applications. At the second stage, mobile device’s job level optimization adjusts the cloud resource usages to optimize the utility of single mobile device’s application. In the simulations, compared with other algorithm, our proposed mobile cloud phased scheduling algorithms achieve the better performance with acceptable overhead.  相似文献   

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