基于位置服务的研究综述

基于位置的服务是指移动终端利用各种定位技术获得当前位置信息,再通过无线通信将这些信息传输给服务提供商,服务提供商根据用户的位置信息以及用户的上下文信息提供个性化的服务。对位置服务按照不同的方面进行了分类,然后分析了基于位置服务中的关键技术,包括定位、信息传输以及位置索引,接着总结了基于位置服务的典型应用,最后指出了存在的一些问题。     

基于Wi-Fi室内定位的校园信息服务平台研究

基于Wi-Fi室内定位的校园信息服务平台是以云计算技术、物联网技术和移动互联网技术为基础,在智慧校园中提供楼宇内位置服务和信息发布服务的一套系统,校园用户可以通过智能终端获取校园信息位置服务。该平台主要是通过用户智能终端的APP设计和基于C/S模式的后台服务器"云"的搭建,从而实现在智慧校园中的定位信息服务。     

一种改进的位置信息服务方法

在许多情况下,移动主机需要获得网络中其他移动主机精确或概略的位置信息,即需要一种位置服务。在对目前现有的 5种位置服务即位置信息洪泛、DREAM位置服务、简单位置服务、反应式位置服务和GLS位置服务进行简单描述和性能比较的基础上,提出了一种新的位置服务,简单新位置更新服务(SNLUS)。它通过在位置信息表中增加“信息更新标识”对目前较好的简单位置服务协议(SLS)进行了改进。仿真结果说明,该算法可以用较少的开销获得较好的位置信息服务。     

LBS的一种隐私保护模型

移动位置服务(LBS)是一个分布式多方参与的系统,给移动商业应用带来了一个快速发展的时机,但由于其拥有访问私人信息的权利,以至于也给它们的用户隐私带来很大的风险.为此,通过对能够有效保护用户隐私的模型进行了研究,提出了一个体系结构和一个协议,协议中使用一个位置中间件把来自LBS供应商提供的用户关心的区域信息和来自移动运营商的用户位置信息进行匹配.结果表明,该协议使得隐私友好的服务成为可能,而且仍然是高效率.     

基于手机位置信息的实时路况信息服务

由于位置服务（LBS,Location Based Service）具有广阔的市场前景,特别是实时交通路况信息服务,更是国内外研究的一个热点。近几年来,研究人员已进行了一系列基于位置服务的研究,但通过手机定位信息来获取路况信息尚无研究提及。本文的主要贡献是首次提出基于手机的位置和移动速度为用户提供路况信息服务（LSBTIS,Location and Speed Based Traffic Information Service）。本文从国内外实时路况信息服务的研究现状、LSBTIS的实现原理、LSBTIS的优势以及LSBTIS的市场前景几个方面来探讨提出的基于手机位置和移动速度的实时交通路况信息服务。     

云计算时代的位置服务

位置服务将成为云计算的示范应用,有望成为移动互联标配,位置服务(LBS:location-based service)是指采用卫星定位技术获取的用户终端的位置信息,通过移动通信网络,在电子地图平台的支持下提供给用户本人或他人以及通信系统,实现定位、导航、查询、识别和事件检查等与空间位置相关的增值服务业务。     

基于移动互联网的智能化导游软件设计——以西溪湿地为例

杭州市贯彻落实十二五旅游发展规划过程中,大力推进数字化智能化景区的建设,通过信息技术提升公共服务能力成为智能化景区建设的重要建设内容。随着移动互联网的高速发展和智能终端的普及,越来越多的人们喜欢通过智能手机来获取相关的资讯信息。本文结合用户实际需求以及移动互联网技术设计了基于移动互联网的智能化导游软件,通过与手机位置服务的结合,提供了更加准确、更加针对游客需求、更具有随时随地性的个性化导游服务。     

移动位置服务应用平台研究与开发

提出了一种移动位置服务的体系结构,开发、设计了其中的关键部件移动位置服务网关和位置服务应用平台,给出了实现位置服务的应用程序设计流程。经过实际测试表明,系统能够应用于移动通信网络为用户提供位置服务。     

基于密文检索的位置服务用户隐私保护方案

在基于位置服务系统中,为用户提供高质量服务的同时如何很好地保护用户的隐私(身份、行踪以及偏好等)仍然是一个挑战.针对这一挑战,提出了基于密文检索的位置服务用户隐私保护方案.在本方案中,位置服务提供商将其服务数据以及数据向量索引以密文的形式外包给云端,移动用户通过密文查询请求向云端查询所需服务,云端通过用户的查询以及服务数据索引计算出匹配度高的服务数据并返回给用户,整个交互过程都是以密文形式进行,云端以及外界得不到任何明文信息.本方案不依赖集中匿名器和用户协作,最后通过理论以及实验分析表明,本方案以低的计算开销有效地保护了用户的身份、位置以及查询偏好隐私.     

移动终端位置服务系统的实现

分析了移动终端位置服务的必要性和可行性,阐述了移动终端服务系统的基本内容,设计出移动终端位置服务系统的结构框架,给出了移动终端位置服务系统中客户端、服务器端及第三方内容和地理移动服务3个关键部分的实现模式,最后展望了移动终端位置服务系统的应用前景.     

基于位置的手机博客系统设计与实现

随着移动产业发展和移动技术提高,基于用户位置的业务迅速发展,如:紧急援助、信息查询等,基于位置业务创新已经成为移动产业发展的巨大推动力。文中在ISG平台上设计和实现基于位置的手机博客系统。与传统的手机博客系统相比较,文中引入用户位置信息。用户写博客时,系统自动记录用户的位置信息,并把用户位置与其所写博客动态绑定存储;用户可以根据自己的位置动态搜索博客。     

An Ontology-Based Approach to Personalized Situation-Aware Mobile Service Supply

Mobile devices such as personal digital assistants (PDAs) and mobile phones are in widespread use already today and converging to mobile smart phones. They enable users to access a wide range of services and information without guidance through their actual demands. Especially during mass events like the Olympic Games 2008 in Beijing—which was initially the context of our work—a large service space is expected to support all mobile visitors, being athletes, journalists, or spectators. Current approaches tackling such problems are location based, meaning that a user's location is central to service provision, and even context-aware, meaning that, beyond location, characteristics of a user's environment are taken into account. Such information obviously helps to deliver relevant information at the right time to the mobile users. Going one step further, a situation-aware system abstracts from the context dimensions by translating specific contexts into logical situations. Knowing the situation end users are in allows the system to better identify the information to be delivered to them and to choose the appropriate services with regard to their scope, which is referred to as service roaming. Even though many context frameworks have been introduced in the past few years, what is usually missing is the notion of characteristic features of contexts that are invariant during certain time intervals. This paper presents these concepts in the context of a platform development, namely FLAME2008, which is able to support its mobile users with personalized situation-aware services in push and pull mode.     

基于位置信息的流式移动应用推送系统的研究

目前与位置相关的移动应用越来越多,传统应用分发模式中,用户需要手动对应用进行搜索、下载、安装以及卸载,不利于提升用户使用应用服务的体验。设计并实现了基于位置信息的流式移动应用推送系统,该系统中服务器利用移动终端位置信息将相关应用解析、安装,并推送到移动终端显示,移动终端根据用户的选择从服务器流式加载应用。该系统使得用户在切换位置时,不用下载、安装即可使用和当前位置相关的应用服务。实验表明,和传统应用分发模式相比,在3G网络环境下可以减少64.37%的应用获取时延,在4G网络环境下可以减少74.49%的应用获取时延。     

Look, Ma, My homepage is Mobile!

Much of the ongoing research in ubiquitous computing has concentrated on providing context information, e.g. location information, to the level of services and applications. Typically, mobile clients obtain location information from their environment which is used to provide “locally optimal” services. In contrast, it may be of interest to obtain information about the current context a mobile user or device is in, from a client somewhere on the Web, i.e. to use the mobile device as an information provider for Internet clients. As an instance of such services we propose the metaphor of a “location-aware” Web homepage of mobile users providing information about, e.g. the current location a mobile user is at. Requesting this homepage can be as easy as typing a URL containing the mobile user's phone number such ashttp://mhp.net/+49123456789 in an off-the-shelf browser. The homepage is dynamically constructed as Web users access it and it can be configured in various ways that are controlled by the mobile user. We present the architecture and implementation and discuss issues around this example of “inverse” ubiquitous computing.     

Trading privacy with incentives in mobile commerce: A game theoretic approach

In mobile commerce, companies provide location based services to mobile users, who report their locations with a certain level of granularity to maintain a degree of anonymity. This level of granularity depends on their perceived risk as well as the incentives they receive in the form of monetary benefits or improved mobile services. This paper formulates a quantitative model in which information theoretic metrics such as entropy, quantify the anonymity level of mobile users. The individual perceived risks of users and the benefits they obtain are defined as functions of their chosen location information granularity. The interaction between the mobile commerce company and its users is investigated using mechanism design techniques as a privacy game. The user best responses and optimal strategies for the company are derived under budgetary constraints on incentives, which are provided to users in order to convince them to share their private information at the desired level of granularity. Information limitations in the system are analyzed to capture more realistic scenarios where the companies do not have access to user utility functions. Iterative distributed algorithm and regression learning methods are investigated to design mechanisms that overcome these limitations. The results obtained are demonstrated with a numerical example and simulations based on real GPS data.     

Efficient mining and prediction of user behavior patterns in mobile web systems

The development of wireless and web technologies has allowed the mobile users to request various kinds of services by mobile devices at anytime and anywhere. Helping the users obtain needed information effectively is an important issue in the mobile web systems. Discovery of user behavior can highly benefit the enhancements on system performance and quality of services. Obviously, the mobile user's behavior patterns, in which the location and the service are inherently coexistent, become more complex than those of the traditional web systems. In this paper, we propose a novel data mining method, namely SMAP-Mine that can efficiently discover mobile users' sequential movement patterns associated with requested services. Moreover, the corresponding prediction strategies are also proposed. Through empirical evaluation under various simulation conditions, SMAP-Mine is shown to deliver excellent performance in terms of accuracy, execution efficiency and scalability. Meanwhile, the proposed prediction strategies are also verified to be effective in measurements of precision, hit ratio and applicability.     

基于基站的移动终端定位的研究及应用

随着移动终端、3G网络的快速发展与结合,公众对于获取位置信息的需求迅速增长.基于基站的定位系统的发展是非常有必要的.针对移动网络原理、Android技术进行研究后,提出通过定位软件获取GSM网络中移动终端用户的位置信息,在服务器端对数据保存及处理,最后在电子地图的支持下,为用户提供一种定位服务.经过测试,这种定位服务不仅能给普通群体提供定位和轨迹查询服务,更能免费为老人、孩子等弱势群体的人身安全提供保障.     

Spatial cloaking for anonymous location-based services in mobile peer-to-peer environments

This paper tackles a privacy breach in current location-based services (LBS) where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. For example, a user who wants to issue a query asking about her nearest gas station has to report her exact location to an LBS provider. However, many recent research efforts have indicated that revealing private location information to potentially untrusted LBS providers may lead to major privacy breaches. To preserve user location privacy, spatial cloaking is the most commonly used privacy-enhancing technique in LBS. The basic idea of the spatial cloaking technique is to blur a user’s exact location into a cloaked area that satisfies the user specified privacy requirements. Unfortunately, existing spatial cloaking algorithms designed for LBS rely on fixed communication infrastructure, e.g., base stations, and centralized/distributed servers. Thus, these algorithms cannot be applied to a mobile peer-to-peer (P2P) environment where mobile users can only communicate with other peers through P2P multi-hop routing without any support of fixed communication infrastructure or servers. In this paper, we propose a spatial cloaking algorithm for mobile P2P environments. As mobile P2P environments have many unique limitations, e.g., user mobility, limited transmission range, multi-hop communication, scarce communication resources, and network partitions, we propose three key features to enhance our algorithm: (1) An information sharing scheme enables mobile users to share their gathered peer location information to reduce communication overhead; (2) A historical location scheme allows mobile users to utilize stale peer location information to overcome the network partition problem; and (3) A cloaked area adjustment scheme guarantees that our spatial cloaking algorithm is free from a “center-of-cloaked-area” privacy attack. Experimental results show that our P2P spatial cloaking algorithm is scalable while guaranteeing the user’s location privacy protection.     

基于无线局域网的室内临近位置检测代理实现

传统基于网络的位置服务系统主要是为远程用户提供查询移动对象位置的信息服务。而现有基于移动终端的位置感知服务不能满足位置上下文应用的要求．为了达到系统自动自发的上下文交互目的。需要在应用中定义一个位置检测代理来捕获移动设备的位置变化事件．生成有效的上下文信息．本文使用简单贝叶斯分类算法实现了基于无线局域网的临近位置检测代理．在室内环境中进行实验表明。该方法可根据实际需要调整位置检测的范围与准确度。具有可行性与灵活性．     

Involving users early on in the design process: closing the gap between mobile information services and their users

Designing mobile information services, including mobile Internet services, mobile banking, interactive mobile television, location-based services etc. that capture a mass market has not been easy, and there have been many disappointments over the past years. There are still uncertainties with regard to the kinds of mobile services users want and need. We argue that users wants and needs depend on their context, which means that users should play an important role in the design process of mobile information services, through a structured approach in which developers and users work together. In this paper, we present a group-based approach to include the user early on in the design process in an efficient way. We have applied the group-based approach in three cases, i.e. mobile services for campus visitors, wireless applications for the process industry and services for crisis management. In all cases, involving users early on in the design process enabled the developers to gather useful information for designing mobile information services.