一种基于差异化服务的MEC应用实例智能迁移机制

基于ETSI提出的MEC系统移动用户应用实例智能迁移机制,提出了一种增强的基于差异化服务的应用实例智能迁移机制。根据需要迁移的用户数量和业务数量定义了 4 种状态消息同步模式,使得运营商可以对具有不同服务性能优先级请求的用户和业务的处理具有更大的灵活性,为实现差异化服务和计费提供了更多的选择。     

A robust omnidirectional vision sensor for soccer robots

How to make robot vision work robustly under varying lighting conditions and without the constraint of the current color-coded environment are two of the most challenging issues in the RoboCup community. In this paper, we present a robust omnidirectional vision sensor to deal with these issues for the RoboCup Middle Size League soccer robots, in which two novel algorithms are applied. The first one is a camera parameters auto-adjusting algorithm based on image entropy. The relationship between image entropy and camera parameters is verified by experiments, and camera parameters are optimized by maximizing image entropy to adapt the output of the omnidirectional vision to the varying illumination. The second one is a ball recognition method based on the omnidirectional vision without color classification. The conclusion is derived that the ball on the field can be imaged to be an ellipse approximately in our omnidirectional vision, and the arbitrary FIFA ball can be recognized by detecting the ellipse imaged by the ball. The experimental results show that a robust omnidirectional vision sensor can be realized by using the two algorithms mentioned above.     

移动通信中的安全策略

在移动通信中 ,安全对用户和运营者都是至关重要的。与其它通信系统相比 ,移动通信有其特殊需要和固有的缺陷 ,因此应特别关注。本文通过对 2G和 3G中的安全隐患及防护策略来讲述移动通信中的安全策略。     

The AROUND Architecture for Dynamic Location-Based Services

This paper presents a generic concept of location-based service as an abstraction for supporting the association between computational resources and location. The objective is to extend the advantages of service-based architectures to the development of location-based systems, thus providing a more open and extensible alternative to the vertical approaches typically used in this type of system. The novel AROUND architecture is proposed as an approach for supporting location-based services in the Internet environment. AROUND provides a service location infrastructure that allows applications to select services that are specifically associated with their current location. The architecture includes a flexible scope model that defines the association between services and location, and a service location infrastructure organised by spatial criteria and optimised for location-based queries. Based on a prototype implementation of this architecture, we have developed two case studies that illustrate the use of this approach for developing location-based systems. The overall results provide a valuable insight into the applicability of the architecture, and suggest that this model of location-based services can provide a useful approach for the development of a wide range of location-based applications.     

Object Request Brokers in Mobile Computing

The widespread use of wireless and mobile networks and devices requiresspecial programming techniques and solutions. The object request brokers ofmobile environments have to adopt these techniques and offer servicesdealing with the problems of mobility. Most of the existing object request brokers however were developed for fixed networks assuming reliable transport protocols (mostly TCP), while the mobile networks cannot offer high qualitytransport.In this paper we give an overview of the challenges and solutions in mobilecomputing and present our ORB(M) framework implementing services based onthe solutions. Extending the framework doesn't require the assistance of itsdevelopers, the user can implement application-specific semantic elementsand deploy various new methods bound to the process of remote invocation.The user can form arbitrary new invocation semantics based on these elementsand customise the invocation semantics used by a given method. Our newmobility-related semantic elements offer solutions to the challengesof mobility allowing the user to concentrate on theessential problems of the application and handling.     

Which One Should be Chosen for the Mobile Geographic Information Service Now, WAP vs. i-mode vs. J2ME?

The concepts of MGIS (Mobile Geographic Information System), LBS (Location Based Service) and MGI Service (Mobile Geographic Information Service) were introduced first. Then the consistency of the three wireless Internet access technology, WAP (Wireless Application Protocol), i-mode and J2ME (Java^™ 2 Micro Edition) were proposed not only from the surfaces, but also from the architectures. Based on the analysis of the WAP, i-mode and J2ME, the suggested suitable field of each technology was discussed. WAP and i-mode are adapted to fields of public services in wireless Internet field with Browser/Server structures, and J2ME is adapted to the fields of private services in wireless Internet field with Client/Server structure. There are no competitions among these three technologies, and each of the three is a tactical technology. They will coexist for a long period, and now we should focus more on how to use a new integrated architecture of different technologies to solve more complex spatial-related questions in the mobile service field than discussing which one is the best. And maybe all three will be replaced in the future when a brand-new direct-connected way to browse the Internet Geographic Information Web Service is developed.

Spectral properties of signal fading and Doppler spectra distribution in urban mobile communication links

In this work, we continue the analysis of a probabilistic approach and the corresponding stochastic multi‐parametric model of wave propagation, in built‐up areas with randomly distributed buildings. We have concentrated on the spectral properties of signal strength spatial variations and on Doppler spread spectrum distribution of signal power. The analysis is based on a unified stochastic approach of radio wave propagation above the built‐up terrain with applications to mobile communications. We analyze the signal power spectrum of spatial frequencies and the signal power distribution in the Doppler domain for moving vehicles, taking into account a Doppler shift proportional to the vehicle antenna speed relative to the base station. The comparison between the theoretical prediction and experimental data was motivated by the proposed stochastic model and other existing statistical models to verify the signal power distribution in the Doppler domain for various urban environments and terminal heights with respect to building rooftops. New effects of terrain features on signal spectrum are obtained, examined and compared with existing models. Copyright © 2006 John Wiley & Sons, Ltd.     

基于智能手机平台高清语音的设计与实现

MT6572平台是由联发科公司推出的双核Cortex-A7主频1.0GHz的智能手机平台。该平台支持AMR-NB和AMR-WB语音编解码,支持双麦克风噪声消除算法等等。文章介绍了MT6572平台的语音性能特点和高清语音的具体要求,并提出了手机实现高清语音的设计要点。     

基于OMA标准的FOTA技术研究

本文介绍了近年来出现的以FOTA(固件更新)技术为代表的MDM(移动设备管理)发展现状,主要研究了基于OMA(开放移动联盟)标准的FOTA技术框架和一些关键技术特征,最后对FOTA在中国移动市场所面临的问题进行了分析.     

基于RFID专用读写模块和IC卡的手机支付新方案的研究

本文首先研究了移动支付业务需求、业务模式、技术背景与实现方式,然后描述了将RFID技术与移动通信技术相结合实现移动支付业务的技术方案,最后针对国内移动支付的发展现状,详细介绍了基于RFID专用读写模块和IC卡的手机移动支付新方案.