Social functions of location in mobile telephony

Location appears to be one of the most important aspects of context in mobile communication. It is a complex piece of information involving several levels of detail. Location intertwines with other relevant aspects of context: the parties’ present activity, relative time and identities. The analysis of mobile conversations provides insights into the functions of “location” for mobile users. Most mobile calls involve a sequence in which location is reported. Location is made relevant by the parties’ activities. Location telling takes place in five different activity contexts during mobile calls. Location may be an index of interactional availability, a precursor for mutual activity, part of an ongoing activity, or it may bear emergent relevance for the activity or be presented as a social fact. Typically, joint activities make relevant spatio-temporal location such as distance in minutes from the meeting point via the vehicle used. For users, location does not appear to be relevant in purely geographical terms.     

Protecting location privacy in mobile geoservices using fuzzy inference systems

Mobile geoservices, especially location-based services (LBSs), are becoming more popular each day. The most important goal of these services is to use a user’s location to provide location-aware services. Because the user’s spatial information can be abused by organizations or advertisers, and sometimes for criminal purposes, the protection of this information is a necessary part of such services. There has been substantial research on privacy protection in LBSs and mobile geoservices; most studies have attempted to anonymize the user and hide his/her identity or to engage the user in the protection process. The major defects of these previous approaches include an increased complexity of system architecture, a decrease in service capabilities, undesirable processing times, and a failure to satisfy users. Additionally, anonymization is not a suitable solution for context-aware services. Therefore, in this paper, a new approach is proposed to locate users with different levels of spatial precision, based on his/her spatio-temporal context and a user’s group, through fuzzy inference systems. The user’s location and the time of the request determine the spatio-temporal context of the user. A fuzzy rule base is formed separately for each group of users and services. An interview is a simple method to extract the rules. The spatial precision of a user’s location, which is obtained from a fuzzy system, goes to a spatial function called the conceptualization function, to determine the user’s location based on one of the following five levels of qualitative precision: geometrical coordinates, streets, parish, region, and qualitative location, such as the eastern part of the city. Thus, there is no need to anonymize users in mobile geoservices or to turn the service off. The applicability and efficiency of the proposed method are shown for a group of taxi drivers.     

QoE prediction model for mobile video telephony

Interactive online video applications, such as video telephony, are known for their vulnerability to network condition. With the increasing usage of hand-held wireless mobile devices, which are capable of capturing and processing good quality videos, combined with the flexibility in an end-user movements have added new challenging factors for application providers and network operators. These factors affect the perceived video quality of mobile video telephony applications, unlike conventional video telephony over desktop computers. We investigate this impact on video quality of mobile video telephony in varying network conditions and end-users movement scenarios. Based on 312 live traces, we quantitatively derive the correlation between the perceived video quality and the network Quality of Service (QoS) and user mobility. With the results, we develop a Quality of Experience (QoE) prediction model for mobile video telephony using Support Vector Regression techniques. The prediction models display ≈ 0.8 pearson correlation with experimental data. Our methodology and findings can be used to guide the video telephony application providers and network operators to work towards satisfying end-user experience.     

Enhancing WLAN location privacy using mobile behavior

Recently wireless network is massively used in the daily life, but user’s location privacy can be threatened. In a wireless local area network (WLAN), an adversary can track a user through his/her unchanged MAC address. Many correlation researches have been proposed to combat this issue, but they have not included mobile behavior of neighboring nodes as a key factor; therefore, their solutions may miss the opportune moment to update MAC address to improve the user’s location privacy. In other words, the existing schemes in the opportune moment to update MAC address may not be the best one. Furthermore, they will have many unnecessary MAC addresses to be updated; it then causes the network throughput being reduced. In this paper, we are going to enhance user’s location privacy with the relative positioning scheme. We analyze the mobile behavior of neighboring nodes to decide which mobile nodes are going to update their MAC addresses. The experiment results show that our scheme can decrease the time of changing MAC address, and also to enhance the user’s location privacy, although the network throughput is a little decrease.     

MNPA: a mobile network privacy architecture

This paper presents a mobile network privacy architecture (MNPA) that enables the provision of very strong user privacy against external and internal threats within mobile networks. The MNPA extends the mobile networking model with two new components. The first, privacy routing capability, enables untraceable communications between hosts. The second, privacy token issuing authority, is a third party application that manages the flow of MNPA user authorisation tokens in the system. The operations of these two components are detailed.

We follow this by demonstrating how these components can be used to implement protocols for privacy enhanced network operations. New secure methods for location registration, remote host communication and billing are presented. We finish with a discussion of issues of collusion and trust within the architecture and look briefly at public key infrastructure requirements.     

面向移动社交网络的位置隐私保护方法

移动社交网络为人们的生活带来了极大的便利,但用户在享受这些服务带来便利的同时,个人位置隐私受到了严重威胁。首先对用户位置隐私保护需求进行了形式化描述,继而针对用户的敏感兴趣点泄露问题,提出了一种情景感知的隐私保护方法。该方法将位置信息、社交关系、个人信息引入到知识构建算法中以计算兴趣点间的相关性,并利用该相关性及时空情景实时判断发布当前位置是否会泄露用户隐私,进而实现了隐私保护与服务可用性间的平衡。最后通过仿真实验验证了该方法的有效性。     

移动社会性软件中的位置隐私研究

为了保护移动社会性软件中用户的位置隐私,以位置缸匿名模型为基础,基于分布式结构提出了一种移动社会性软件系统中的P2P位置匿名算法.用户在提出服务请求前,查找k-1个用户形成包含自己在内的一个组,覆盖整个组成员的最小区域就是用户匿名后的位置范围.在该算法中引入了复杂网络中度的概念.根据用户度的大小决定查找k-1个用户的方式(单跳/多跳),有效地减少了服务的平均响应时间.实验结果表明,与基于中心服务器结构的匿名算法相比,该算法有较强的可扩展性和有效性.     

Preserving location privacy without exact locations in mobile services

Privacy preservation has recently received considerable attention in location-based services (LBSs). A large number of location cloaking algorithms have been proposed for protecting the location privacy of mobile users. However, most existing cloaking approaches assume that mobile users are trusted. And exact locations are required to protect location privacy, which is exactly the information mobile users want to hide. In this paper, we propose a p-anti-conspiration privacy model to anonymize over semi-honest users. Furthermore, two k*NNG-based cloaking algorithms, vk*NNCA and ek*NNCA, are proposed to protect location privacy without exact locations. The efficiency and effectiveness of the proposed algorithms are validated by a series of carefully designed experiments. The experimental results show that the price paid for location privacy protection without exact locations is small.     

Modeling privacy control in context-aware systems

Significant complexity issues challenge designers of context-aware systems with privacy control. Information spaces provide a way to organize information, resources, and services around important privacy-relevant contextual factors. In this article, we describe a theoretical model for privacy control in context-aware systems based on a core abstraction of information spaces. We have previously focused on deriving socially based privacy objectives in pervasive computing environments. Building on Ravi Sandhu's four-layer OM-AM (objectives, models, architectures, and mechanisms) idea, we aim to use information spaces to construct a model for privacy control that supports our socially based privacy objectives. We also discuss how we can introduce decentralization, a desirable property for many pervasive computing systems, into our information space model, using unified privacy tagging.     

Treating data privacy in distributed systems

This papers describes and is primarily concerned with the security data definition and management in a distributed data base of aggregated type, although the approach described may be applied to any distributed system architecture. A multi-level logical security architecture is presented reflecting the logical architecture of the distributed system. In particular, three security logical schemata are proposed: the network security schema, the external security schemata, and the intermediate security schemata. For each schema data models are introduced, allowing the definition and the management of security information. Mapping rules between the logical levels are discussed. Finally security mechanisms are analyzed.     

Beyond 3G video mobile video telephony: The role of 3G-324M in mobile video services

3G-324M is a 3 ^rd Generation Partnership Project (3GPP) umbrella standard for wireless video communications, which was created to satisfy the stringent requirements of real-time, low-delay interactive conversational video services. However it is, in practice, employed today in 3G networks to enable also a variety of multimedia services including messaging, streaming video chat and portals. The unification of this variety of services under the same umbrella standard has significance for the design of the supporting architectures and the applications that run such services. In this paper we will discuss the current advantages and limitations of the 3G-324M standard in supporting such services     

Beyond 3G video mobile video telephony: The role of 3G-324M in mobile video services

3G-324M is a 3^rd Generation Partnership Project (3GPP) umbrella standard for wireless video communications, which was created to satisfy the stringent requirements of real-time, low-delay interactive conversational video services. However it is, in practice, employed today in 3G networks to enable also a variety of multimedia services including messaging, streaming video chat and portals. The unification of this variety of services under the same umbrella standard has significance for the design of the supporting architectures and the applications that run such services. In this paper we will discuss the current advantages and limitations of the 3G-324M standard in supporting such services     

E-MIIM: an ensemble-learning-based context-aware mobile telephony model for intelligent interruption management

AI & SOCIETY - Nowadays, mobile telephony interruptions in our daily life activities are common because of the inappropriate ringing notifications of incoming phone calls in different contexts....     

A social interaction system based on cloud computing for mobile video telephony

As the use of smartphones become popular,people heavily depend on smartphone applications to deal with their social activities.For this reason,traditional message texting between mobile applications does not fulfill the versatile requirements of social networking.Many mobile applications use multimodality to deliver multimedia messages including sticker,voice and photo message,video call,and snap movie to enhance the communicative capability.However,without face-to-face interaction,people may fail to detect the other side’s non-verbal social behavior such as fine-grain facial expressions,body movements,or hand gesture.During social interaction,non-verbal behavior conveys information about the involved individuals and help the speakers express their social emotion in an implicit way.It is so important for real-world face-to-face interaction but is often blocked on the mobile telephony.To cope with this problem,we propose an afective computing model to assist the representation of social emotion and then help the progress of social interaction on the mobile telephony.In this model,for the purpose of real-time afective analysis,we delegate the computing loading to the cloud side service and enhance the system’s scalability and availability.The result of this experiment approves the feasibility of our system design for the applications of social intelligent.Also,the system provides a research framework of the social intelligent system on the mobile telephony.     

Analysis of fading statistics in cellular mobile communication systems

Spatial channel models are often proposed for modeling the angular aspects of mobile radio channel in picocell, microcell, and macrocellular environments. These models are validated through comparison with available measurement results. The comparisons are usually based on the fitness of their pdfs of angle of arrival to the histogram of occurrences of the signals over an angular span, given in the measurement data. This paper presents a comparison of the notable scattering models with various spatial channel measurements. The paper suggests criteria for the comparative analysis of the previously proposed spatial channel models and measurements on the basis of their fading statistics. Quantitative analysis of the considered models and the field measurements is also presented using multipath shape factors i.e. angle spread, the angular constriction and direction of maximum fading. Based on the obtained shape factors, fading statistics like level crossing rates, average fade duration, auto-covariance and coherence distance are evaluated. Effect of increasing Doppler spread on the level crossing rates and average fade duration is also elaborated in detail.     

Motion vector refinement in a Wyner--Ziv to H.264 transcoder for mobile telephony

The authors develop a decoder/encoder system (transcoder) to solve the consumption constraint in the communications between end-user devices, when a new Wyner?Ziv (WZ)/H.264 framework is defined for being used in mobile-to-mobile environments. This approach is based on leaving to the devices only WZ video encoding and traditional video decoding; the lowest complexity algorithms in both paradigms. The system shifts the burden of complexity to the network, where an improved transcoder that reuses information between both paradigms is allocated. The WZ decoding motion vectors are used to reduce the H.264 motion estimation process. The proposed transcoder offers a complexity reduction up to 60% on average, without any rate distortion drop.