TBFN: Trust Based Friend Network Design by Analyzing User’s Voice Call and SMS Pattern

Due to rapid development of Web 2.0 Technology social networking have gained explosive growth. This paper proposes a comparatively new approach to build a trust based social network named Trust Based Friend Net (TBFN) for smartphone users. In TBFN, call log and sms log extracted from user’s smartphone are outsourced into the corresponding social network cloud. Analyzing those real datasets the cloud service provider determines trust values of different direct and indirect friends of smartphone users. Global analysis of everyone’s data results in forming a trusted global social network that is free from fake profiles and that minimizes unscrupulous activities.     

Cloud-assisted Computing for Event-driven Mobile Services

Today, software developers for desktop computing build request and respond applications to do what end users tell them to do and answer what they ask. In mobile computing, software developers will need to develop sense and response applications that will interact with the end user. These applications will notify or ask users what they want based on what they have sensed or on a personal profile. Mobile cloud computing has the potential to empower mobile users with capabilities not found in mobile devices, combining different and heterogeneous data sets. In this work, we discuss the importance and challenges in designing event-driven mobile services that will detect conditions of interest to users and notify them accordingly.     

Database Correlation Method with Error Correction for Emergency Location

The constantly growing number of mobile terminal users increases also the number of mobile originated emergency calls. In the United States mobile terminal location in case of an emergency call was mandated with stringent accuracy requirements by Federal Communications Commission (FCC) in 1996. Since July 2003 emergency call location is required also in the European Union (EU), but contrary to the US, without accuracy limits. The global positioning system (GPS) offers high location accuracy, but the density of GPS-capable terminals is very low. Thus, to be able to provide location estimations for all mobile originated emergency calls nationwide, techniques based on cellular network are preferred. In many cases, however, conventional techniques cannot provide sufficient accuracy. This is typical especially for urban areas, where obstacles in signal propagation path degrade location estimation. In urban areas the mobile terminal user density is high and a substantial part of urban emergency calls are mobile originated requiring accurate location estimation. In this paper, we propose a method for emergency call location in urban areas. This database correlation method (DCM) is complemented by error correction method (ECM) developed in the frame of the EU IST project cellular network optimization based on mobile location (CELLO) [http://www.telecom.ntua.gr/cello/]. In performance evaluations DCM has proven to offer sufficient urban accuracy of 44 m in GSM field trial and 25 m in UMTS simulations. The ECM has been tested and proven to ease the implementation of DCM.     

Hybrid model for dynamic evaluation of trust in cloud services

Cloud computing, a new paradigm in distributed computing, has gained wide popularity in a relatively short span of time. With the increase in the number, functionality and features of cloud services, it is more and more mind-boggling for the cloud users to find a trustworthy provider. Cloud users need to have confidence in cloud providers to migrate their critical data to cloud computing. There must be some means to determine reliability of service providers so that users can choose services with the assurance that the provider will not act malignantly. An effort has been made in this paper to formulate a hybrid model to calculate the trustworthiness of service providers. Cloud services are evaluated and trust value is calculated based on compliance and reputation. Service logs based compliance reflects dynamic trust. The reputation has been computed from collective user feedback. Feedback rating is the view of each user about the invoked services. The discovered services that fulfill the user requirements are ranked based on their trust values and top-k cloud services are recommended to the user. The proposed approach is efficient and considerably improves service-selection process in cloud applications.     

Research on cloud computing users’ public safety trust model based on scorecard-random forest

Traditional cloud computing trust models mainly focused on the calculation of the trust of users’ behavior.In the process of classification and evaluation,there were some problems such as ignorance of content security and lack of trust division verification.Aiming to solve these problems,cloud computing users’ public safety trust model based on scorecard-random forest was proposed.Firstly,the text was processed using Word2Vec in the data preprocessing stage.The convolution neural network (CNN) was used to extract the sentence features for user content tag classification.Then,scorecard method was used to filter the strong correlation index.Meanwhile,in order to establish the users’ public safety trust evaluation model in cloud computing,a random forest method was applied.Experimental results show that the proposed users’ public safety trust evaluation model outperforms the general trust evaluation model.The proposed model can effectively distinguish malicious users from normal users,and it can improve the efficiency of the cloud computing users management.     

移动云计算安全问题及安全度量方法浅析

移动云计算安全度量是云计算安全中的一个研究领域,主要是研究采用手机等移动终端设备,通过移动互联网使用云计算服务过程中的安全问题及安全度量方法。本文分析了目前移动云计算行业发展过程中存在的安全问题,指出了这些安全问题是阻碍用户使用云计算服务的关键,分析了传统的安全度量方法在移动云计算中的应用的优缺点,并在此基础上提出了一种基于场景的移动云计算安全度量方法,该方法可以有效度量和展示用户正在使用的云计算服务的安全情况,可以解除用户对于安全的顾虑,让用户放心使用。     

Comparison of signaling loads for PCS systems

We present a comparison of the control signaling load of two vastly different architectures for providing personal communication services (PCSs). One architecture is based on current cellular networks. The other architecture, called the wireless distributed call processing architecture (WDCPA), distributes processing from the mobile switching centers and cell sites and executes new procedures for tracking mobile users and locating mobile users to deliver calls. We determine the signaling load generated within each system to support mobility management and call control based on standard assumptions about the operating parameters of a cellular network. Our results show that, when compared to current cellular systems, for simple single-connection services, WDCPA has marginally reduced cross-network signaling loads. For multiconnection calls, WDCPA incurs 35% less total signaling load for mobility management, has reduced cross-network signaling load for mobility management by up to 65%, and depending on the user model (e.g., data or telecommunication), has reduced total cross-network signaling load, including procedures for call/connection and mobility management, by up to 55% when compared to current cellular systems, while more flexibly supporting services     

个性化搜索中一种基于位置服务的隐私保护方法

在基于位置服务的个性化搜索中,利用可信第三方服务器以及对等节点是保护用户隐私的主要方法,但在现实生活中,它们却是不完全可信的。为了解决这一问题,该文提出一种个性化搜索中基于位置服务的隐私保护方法。该方法通过转换用户的位置信息,并根据用户的查询类型生成用户模型,进而形成带有用户位置信息的查询矩阵,然后利用矩阵加密用户的查询,隐藏查询矩阵中的用户信息,最后根据安全内积计算返回相关性得分最高的前K个查询文件给用户。安全性分析表明该方法能有效地保护用户的查询隐私和位置隐私,通过分析与实验表明,该方法大幅度地缩短了索引构建时间,降低了通信开销,同时为用户提供了基于位置的个性化搜索结果,一定程度上解决了移动设备屏幕小带来的弊端。     

一种公网集群系统的资源预留和接纳控制策略

主要研究了资源预留策略(RR)和接纳控制策略(CAC),提出了一种适合于公网集群环境下基于预测的资源预留和接纳控制策略PRR-CAC。主要目标是减少呼叫掉话率和呼叫阻塞率,同时最大化带宽利用率。通过分析用户移动的历史信息进行数据挖掘,生成该用户的本地配置文件和全局配置文件,通过配置文件来反应用户的真实移动习惯,去预测他们将来的移动路径。通过与FR-CAT2和PR-CAT4的仿真比较,结果表明提出的策略明显优于其他的2种策略。     

New call blocking versus handoff blocking in cellular networks

In cellular networks, blocking occurs when a base station has no free channel to allocate to a mobile user. One distinguishes between two kinds of blocking, the first is called new call blocking and refers to blocking of new calls, the second is called handoff blocking and refers to blocking of ongoing calls due to the mobility of the users. In this paper, we first provide explicit analytic expressions for the two kinds of blocking probabilities in two asymptotic regimes, i.e., for very slow mobile users and for very fast mobile users, and show the fundamental differences between these blocking probabilities. Next, an approximation is introduced in order to capture the system behavior for moderate mobility. The approximation is based on the idea of isolating a set of cells and having a simplifying assumption regarding the handoff traffic into this set of cells, while keeping the exact behavior of the traffic between cells in the set. It is shown that a group of 3 cells is enough to capture the difference between the blocking probabilities of handoff call attempts and new call attempts. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cloud-Assisted Mood Fatigue Detection System

This paper introduces basic concept of mood fatigue detection and existing solutions as well as some typical solutions, such as mobile sensing and cloud computing technology. In the first place, we sum up main challenges of mood fatigue detection and the direction of future study. Then one type of system implementation is put forward, such system consists of: 1) Wearable devices used to detect the users’ mood fatigue; 2) Clouds data center; 3) Application and service manager. We take overall consideration of many factors like the user’s physiological information, external environment conditions and user behavior, evaluate accurately through big data analytic technology the users’ state of mood fatigue and to what extent shall one keeps vigilant as well as what measures shall be adopted to improve the users’ working performance and alert the users to keep themselves away from the danger. Finally a real system is established in this paper, it is composed of the smart clothing, cloud platform and mobile terminal application.     

Performance of MIMO-UWB for LOS and N-LOS Propagation

Mobile cloud computing (MCC) enables ubiquitous access to a diverse range of Internet multimedia services in a pay-as-you-go economic model. In an MCC environment with highly mobile users, the migration of service requests from one cloud server to another due to user movement may frequently occur. We note that when the load offered to the cloud server is increased beyond the capacity limit, particularly when migrated traffic due to user movement suddenly appears, the probability to disrupt existing services gets higher, consequently resulting in the degradation of user quality of experience (QoE). To keep the service disruption probability at an acceptable level so as to maintain a high user-perceived QoE for different classes of multimedia services, this paper proposes a QoE-aware service continuity strategy for the cloud server in an MCC environment. The strategy is based on the buffer-occupancy threshold policy that differentiates newly arriving service requests coming from the mobile users and offers effective protection for migrated service requests against traffic fluctuation in newly arriving service requests. With the proposed strategy, the cloud server can dynamically change the buffer thresholds for different classes of service requests based on the offered traffic load and the user mobility to improve resource utilization, and, most importantly, to keep the service disruption probability at an acceptable level. Besides, by taking the effect of migrated traffic into account, we develop an analytical model to study the performance of the cloud server using the proposed strategy. With the analytical model, we propose an iterative method to determine the optimal buffer thresholds that maximize resource utilization while keeping an acceptable user QoE for different classes of services.

     

Modeap: Moving Desktop Application to Mobile Cloud Service

Thanks to the availability of various mobile applications, lots of users shift from desktop environments, e.g., PCs and laptops, to mobile devices, e.g., smartphones and tablets. However, there are still some desktop applications without counterparts on mobile devices, such as some integrated development environments (e.g., eclipse) and automatic industry control systems. In this paper, we propose Modeap, a platform-independent mobile cloud service that can push all desktop applications developed for various operating systems from cloud servers to mobile devices. Modeap follows a design principle of complete detachment and regeneration of desktop user interface, i.e., the essential graphical primitives of the original desktop applications will be intercepted and then translated into standard web-based graphical primitives such that the interactions between users and remote cloud applications become possible via mobile web browsers. In this way, all desktop applications built upon the same set of graphical primitives can be used on mobile devices in great flexibility without installing any new software. We have developed a proof-of-concept prototype that provides Windows applications from cloud server to mobile web browsers. The results of extensive experiments show that the proposed framework can achieve our design goals with low latency and bandwidth consumption.     

Modeling and performance evaluation of a cellular mobile network

An analytic model of cellular mobile communications networks with instantaneous movement is investigated in this paper. This cellular mobile network is showed to be equivalent to a queueing network and furthermore the equilibrium distribution of this cellular mobile network is proved to have a product form. The explicit expressions for handoff rates of calls from one cell to another, the blocking probability of new calls and handoff calls are then obtained. Actual call connection time (ACCT) of a call in this cellular mobile network is characterized in detail, which is the total time a mobile user engages in communications over the network during a call connection and can be used to design appropriate charging schemes. The average ACCT for both complete call and incomplete call, as well as the probability for a call to be incomplete or complete, are derived. Our numerical results show how the above measures depend on the new call arrival process for some specific reserved channels numbers in each cell. The results presented in this paper are expected to be useful for the cost analysis for updating location and paging in cellular mobile network.     

基于用户兴趣集的在线垃圾邮件快速识别新方法

为在不显著降低垃圾邮件识别精度的同时有效提高邮件识别速度,提出了一种在线垃圾邮件快速识别新方法.首先引入用户正、负兴趣集的概念,结合用户兴趣集及支持向量机对邮件进行分类;然后根据主动学习理论,结合训练集样本密度及改进角度差异方法寻找分类最不确定的样本并推荐给用户进行类别标注;最后将标注后样本及分类最确定性样本加入训练集,并使用样本价值评价新函数淘汰冗余样本以生成新的训练集.实验表明,本文方法的用户标注负担小,垃圾邮件识别精度高、速度快,具有较高的在线应用价值.     

一种分层蜂窝网中基于用户分类的建模分析方法

随着无线网中用户需求的业务量持续增大,且用户具有不同移动性,分层蜂窝结构(HCS)被提出。该文研究一种微小区/宏小区的双层蜂窝结构的网络性能,此系统采用双向溢出策略,呼叫用户根据其速度选择合适的接入层(慢用户接入微小区,快用户接入宏小区)。该文提出一种用户分类建模分析方法(分为快用户和慢用户)来估计分层蜂窝网络性能,它不同于以往的蜂窝层分类(分为微小区层和宏小区层)建模方法。此用户分类模型包括一个快用户模型和一个慢用户模型,两个模型都是简单的一维马尔可夫过程。理论分析和仿真结果都证明了用户分类分析模型的正确性。随后利用此模型分析了为速度阈值的作用和被阻用户重复呼叫情况下的网络性能。     

A Dynamic Reservation-Based Call Admission Control Algorithm for Wireless Networks Using the Concept of Influence Curve

In this paper a dynamic channel reservation and call admission control scheme is proposed to provide QoS guarantees in a mobile wireless network using the concept of influence curve. The basic idea behind the proposed scheme is that a moving user, in addition to its requirements in the current cell, exerts some influence on the channel allocation in neighboring cells. Such an influence is related to the moving pattern of the users and is calculated statistically. Furthermore we developed a general analytical model to calculate the corresponding blocking probabilities for wireless networks with multiple platforms, which removes the commonly used assumption that new calls and handoff calls have same channel holding time. The numerical results demonstrate that our scheme outperforms traditional channel reservation schemes and can effectively adapt to the real time network conditions.     

Enhancing localization accuracy of collaborative cognitive radio users by internal noise mitigation

Location information of mobile primary users is one of the essential requirements for an underlay cognitive radio user to utilize the licensed spectrum efficiently. The performance of various location-based applications such as global navigation satellite system, device to device communication in dense urban 5G network also depends on the localization accuracy. In this paper, a collaborative localization scheme based on received signal strength has been proposed. The weighted centroid localization algorithm has been applied in the proposed network scenario to compute location coordinates of the mobile primary user. Since the channel noise effects are random and unavoidable, this paper has focused on the mitigation of the internal noise by designing a suitable reconfigurable FIR filter after the demodulator stage of a cognitive radio receiver circuit to improve precision of signal measurement during primary user localization. The localization error rate has come down to (1.3–1.62) % after internal noise mitigation. The enhancement in the localization accuracy improves the overall spectrum utilization efficiency and reduces the miss detection and false detection probabilities in the proposed underlay network.

     

A demand assignment system for mobile users in a community ofinterest

The paper presents a high performance wireless access and switching system for interconnecting mobile users in a community of interest. Radio channel and time slot assignments are made on user demand, while the switch operations are controlled by a scheduling algorithm designed to maximize utilization of system resources and optimize performance. User requests and assignments are carried over a low-capacity control channel, while user information is transmitted over the traffic channels. The proposed system resolves both the multiple access and the switching problems and allows a direct connection between the mobile end users. The system also provides integration of voice and data traffic in both the access link and the switching equipment. The “movable boundary” approach is used to achieve dynamic sharing of the channel capacity between the voice calls and the data packets. Performance analysis based on a discrete time Markov model, carried out for the case of optimum scheduling yields call blocking probabilities and data packet delays. Performance results indicate that data packets may be routed via the exchange node with limited delays, even with heavy load of voice calls. Also the authors have proposed scheduling algorithms that may be used in implementing this system     

Mobile Payment Based on Transaction Certificate Using Cloud Self‐Proxy Server

Recently, mobile phones have been recognized as the most convenient type of mobile payment device. However, they have some security problems; therefore, mobile devices cannot be used for unauthorized transactions using anonymous data by unauthenticated users in a cloud environment. This paper suggests a mobile payment system that uses a certificate mode in which a user receives a paperless receipt of a product purchase in a cloud environment. To address mobile payment system security, we propose the transaction certificate mode (TCM), which supports mutual authentication and key management for transaction parties. TCM provides a software token, the transaction certificate token (TCT), which interacts with a cloud self‐proxy server (CSPS). The CSPS shares key management with the TCT and provides simple data authentication without complex encryption. The proposed self‐creating protocol supports TCM, which can interactively communicate with the transaction parties without accessing a user's personal information. Therefore, the system can support verification for anonymous data and transaction parties and provides user‐based mobile payments with a paperless receipt.