User location privacy protection mechanism for location-based services

With the rapid development of the Internet of Things (IoT), Location-Based Services (LBS) are becoming more and more popular. However, for the users being served, how to protect their location privacy has become a growing concern. This has led to great difficulty in establishing trust between the users and the service providers, hindering the development of LBS for more comprehensive functions. In this paper, we first establish a strong identity verification mechanism to ensure the authentication security of the system and then design a new location privacy protection mechanism based on the privacy proximity test problem. This mechanism not only guarantees the confidentiality of the user’s information during the subsequent information interaction and dynamic data transmission, but also meets the service provider’s requirements for related data.     

Privacy from Promises to Protection

Privacy issues are becoming more and more important especially since the cyber and the real world are converging up to certain extent when using mobile devices. Means that really protect privacy are still missing. The problem is, as soon as a user provides data to a service provider the user looses control over her data. The simple solution is not to provide any data but then many useful services, e.g. navigation applications, cannot be used. In order to solve this problem, we propose privacy guaranteeing execution containers (PGEC). Basically the concept is that the application obtains access to the user data in a specially protected and certified environment, the PGEC. PGECs enable applications to access private user data and guarantee that the user data is deleted as soon as the service is quit. The PGEC also restricts the communication between the application and the service provider to what is explicitly allowed by the service user. In addition to those means the PGEC also implements countermeasures against malicious attacks such as modified host systems and covert channel attacks, which might be misusing CPU load to signal data out of the PGEC. Thus, the PGEC guarantees a “one time use” of the provided private data.     

标准与远程医疗服务

远程医疗服务为人们提供了远程获得优质医疗服务的可能性.但远程医疗服务系统本身是一个复杂的系统,提供远程医疗服务,需要患者医疗记录等的数字化和标准化以及医疗设施的互操作性,这对标准工作提出了一些新的需求.本文将重要介绍远程医疗服务的种类、远程医疗服务系统对标准的需求、以及相关标准化工作的进展.     

移动网络中数据业务关键性能指标KPI探讨

移动网络的性能评估是网络规划和优化建设的前提，数据业务的迅速发展为移动网络的性能评估提出新的课题，当前评价数据业务网络的关键性能指标主要有吞吐量、时延等，从网络的容量和质量角度出发提出每用户平均吞吐量和网络资源利用率两个关键性能指标，并分别进行理论分析，为数据业务网络的性能评估提供参考依据。     

LMSS中的遮蔽衰落模式分析

本文对ＬＭＳＳ遮蔽环境中的衰落分布进行了分析，利用现有实验数据和ＥＲＳ模式的基本形式，重新确定了经验模式参数在不同遮蔽条件下与仰角和频率的关系；     

一种基于PLL的CBR业务时钟恢复方案

信元在 ATM 网内传输时,由于网内缓存的存在,造成了信元延时变化。信元延时变化对基于锁相环(PLL)的恒定比特率业务时钟的恢复有很大影响,即时钟的抖动和漂移比较明显。从而使这种基于 PLL 的CBR 业务时钟恢复方案在某些场合不能应用。本文提出了一种基于 PLL 的时钟恢复新方案,该方案可以明显地降低由于信元延时变化而造成的 CBR 业务时钟的抖动和漂移,同时不增加缓存的容量。     

二十一世纪通信发展走向

本文展望了２１世纪初社会、家庭、企业对通信的需求与通信在信息化社会中的重要地位，指出通信事业经营者应向社会提供什么样的通信业务（服务），应建设什么样的通信网来实现这些业务以及未来的网络需要哪些关键性通信技术来支持。     

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.     

Sojourn times in a processor sharing queue with service interruptions

We study the sojourn times of customers in an M/M/1 queue with the processor sharing service discipline and a server that is subject to breakdowns. The lengths of the breakdowns have a general distribution, whereas the on-periods are exponentially distributed. A branching process approach leads to a decomposition of the sojourn time, in which the components are independent of each other and can be investigated separately. We derive the Laplace–Stieltjes transform of the sojourn-time distribution in steady state, and show that the expected sojourn time is not proportional to the service requirement. In the heavy-traffic limit, the sojourn time conditioned on the service requirement and scaled by the traffic load is shown to be exponentially distributed. The results can be used for the performance analysis of elastic traffic in communication networks, in particular, the ABR service class in ATM networks, and best-effort services in IP networks.     

语义Web服务中的信誉度评估方法研究

参考日常生活中人们的交易行为,在网络服务中常用信誉度作为服务选取的依据,然而传统的信誉度评估方法不能全面揭示服务提供方的信誉本质,不能应用到语义Web服务的选取中。经过分析,提出了一个以本体为基础的语义Web服务信誉度评估过程及评估模型,深入研究了信誉度评估算法与具体实现,以提高在语义Web服务选择中的准确性和可靠性。