Showing papers on "Mobile telephony published in 2008"

Spectrum sensing in cognitive radio networks: requirements, challenges and design trade-offs

Abstract: Opportunistic unlicensed access to the (temporarily) unused frequency bands across the licensed radio spectrum is currently being investigated as a means to increase the efficiency of spectrum usage. Such opportunistic access calls for implementation of safeguards so that ongoing licensed operations are not compromised. Among different candidates, sensing-based access, where the unlicensed users transmit if they sense the licensed band to be free, is particularly appealing due to its low deployment cost and its compatibility with the legacy licensed systems. The ability to reliably and autonomously identify unused frequency bands is envisaged as one of the main functionalities of cognitive radios. In this article we provide an overview of the regulatory requirements and major challenges associated with the practical implementation of spectrum sensing functionality in cognitive radio systems. Furthermore, we outline different design trade-offs that have to be made in order to enhance various aspects of the system's performance.

The Rise of People-Centric Sensing

Abstract: Technological advances in sensing, computation, storage, and communications will turn the near-ubiquitous mobile phone into a global mobile sensing device. People-centric sensing will help drive this trend by enabling a different way to sense, learn, visualize, and share information about ourselves, friends, communities, the way we live, and the world we live in. It juxtaposes the traditional view of mesh sensor networks with one in which people, carrying mobile devices, enable opportunistic sensing coverage. In the MetroSense Project's vision of people-centric sensing, users are the key architectural system component, enabling a host of new application areas such as personal, public, and social sensing.

Digital Footprinting: Uncovering Tourists with User-Generated Content

Abstract: Novel methods and tools are being developed to explore the significance of the new types of user-related spatiotemporal data. This approach helps uncover the presence and movements of tourists from cell phone network data and the georeferenced photos they generate. A city's visitors have many ways of leaving voluntary or involuntary electronic trails: prior to their visits, tourists generate server log entries when they consult digital maps or travel Web sites; during their visit, they leave traces on wireless networks whenever they use their mobile phones; and after their visit, they might add online reviews and photos. Broadly speaking then, there are two types of footprint: active and passive. Passive tracks are left through interaction with an infrastructure, such as a mobile phone network, that produces entries in locational logs; active prints come from the users themselves when they expose locational data in photos, messages, and sensor measurements. In this article, we consider two types of digital traces from Rome, Italy: georeferenced photos made publicly available on the photo-sharing Web site Flickr and aggregate records of wireless network events generated by mobile phone users making calls and sending text messages on the Telecom Italia Mobile (TIM) system.

Geographical dispersal of mobile communication networks

Abstract: In this paper, we analyze statistical properties of a communication network constructed from the records of a mobile phone company. The network consists of 2.5 million customers that have placed 810 million communications (phone calls and text messages) over a period of 6 months and for whom we have geographical home localization information. It is shown that the degree distribution in this network has a power-law degree distribution k(-5) and that the probability that two customers are connected by a link follows a gravity model, i.e. decreases as d(-1). where d is the distance between the customers. We also consider the geographical extension of communication triangles and we show that communication triangles are not only composed of geographically adjacent nodes but that they may extend over large distances. This last property is not captured by the existing models of geographical networks and in a last section we propose a new model that reproduces the observed property. Our model, which is based on the migration and on the local adaptation of agents, is then studied analytically and the resulting predictions are confirmed by computer simulations. (C) 2008 Elsevier B.V. All rights reserved.

An overview of the femtocell concept

Abstract: The femtocell concept aims to combine fixed-line broadband access with cellular telephony using the deployment of ultra-low-cost, low-power third generation (3G) base stations in the subscribers' homes or premises. It enables operators to address new markets and introduce new high-speed services and disruptive pricing strategies to capture wireline voice minutes and to grow revenues. One of the main design challenges of the femtocell is that the hierarchical architecture and manual cell planning processes used in macrocell networks do not scale to support millions of femtocells. In this paper, a user-deployed femtocell solution based on the base station router (BSR) flat Internet Protocol (IP) cellular architecture is presented that addresses these problems, and several aspects of the proposed solution are discussed. The overall concept and key requirements are presented in detail. The auto-configuration and self-optimization process from purchase by the end user to the integration into an existing macrocellular network is described. Then the theoretical performance of a co-channel femtocell deployment is analyzed and its impact on the macrocell underlay is assessed. Finally, a financial analysis of a femtocellular home base station deployment in a macrocellular network is presented. It is shown that in urban areas, the deployment of publicly accessible home base stations with slightly increased coverage can significantly reduce the operator's annual network costs (up to 70 percent in the investigated scenario) compared to a pure macrocellular network.

Mobility management for all-IP mobile networks: mobile IPv6 vs. proxy mobile IPv6

Abstract: Recently, a network-based mobility management protocol called Proxy Mobile IPv6 (PMIPv6) is being actively standardized by the IETF NETLMM working group, and is starting to attract considerable attention among the telecommunication and Internet communities. Unlike the various existing protocols for IP mobility management such as Mobile IPv6 (MIPv6), which are host-based approaches, a network-based approach such as PMIPv6 has salient features and is expected to expedite the real deployment of IP mobility management. In this article, starting by showing the validity of a network-based approach, we present qualitative and quantitative analyses of the representative host-based and network-based mobility management approaches (i.e., MIPv6 and PMIPv6), which highlight the main desirable features and key strengths of PMIPv6. Furthermore, a comprehensive comparison among the various existing well-known mobility support protocols is investigated. Although the development of PMIPv6 is at an early stage yet, it is strongly expected that PMIPv6 will be a promising candidate solution for realizing the next-generation all-IP mobile networks.

Decentralized Environmental Modeling by Mobile Sensor Networks

Abstract: Cooperating mobile sensors can be used to model environmental functions such as the temperature or salinity of a region of ocean. In this paper, we adopt an optimal filtering approach to fusing local sensor data into a global model of the environment. Our approach is based on the use of proportional-integral (PI) average consensus estimators, whereby information from each mobile sensor diffuses through the communication network. As a result, this approach is scalable and fully decentralized, and allows changing network topologies and anonymous agents to be added and subtracted at any time. We also derive control laws for mobile sensors to move to maximize their sensory information relative to current uncertainties in the model. The approach is demonstrated by simulations including modeling ocean temperature.

Understanding the behavior of mobile data services consumers

Abstract: Due to rapid advances in the Internet and wireless technologies, a ubiquitous computing world is becoming a reality in the form of mobile computing. At the center of this phenomenon is mobile data services which arise from the convergence of advanced mobile communication technologies with data services. Despite the rapid growth in mobile data services, research into consumers' usage behavior is scarce. This study attempts to identify and empirically assess the factors that drive consumers' acceptance of mobile data services. A research model based on the decomposed theory of planned behavior and incorporating factors that represent personal needs and motivations in using mobile data services is presented. The model is tested via an online survey of 811 consumers of four categories of mobile data services (i.e., communications, information content, entertainment, and commercial transactions) associated with different usage contexts. We found that attitude, social influence, media influence, perceived mobility, and perceived monetary value influence consumers' intention to continue usage of mobile data services. In addition, perceived ease of use, perceived usefulness, and perceived enjoyment influence attitude toward continued usage of mobile data services. Finally, separate analysis of the different categories of mobile data services highlights the influence of individual usage context on consumers' behavior.

Method to sustain TCP connection

Abstract: The present invention relates to network communication systems for managing client/server connections in a wireless environment. In accordance with the invention, a mobile communication unit (ie., client), deploys keep alive packets at selected times in order to reset a keep idle timer of a server (e.g., host computer). By periodically resetting the keep idle timer a current connection between the mobile communication unit and server can be maintained as long as desired even when the mobile communication unit is in a power suspend mode. When in a power suspend mode, the mobile communication unit can briefly awake long enough to activate its transmitter and send a keep alive packet to the server to maintain the current connection. In this manner, the mobile communication unit can obtain the power savings of being in primarily a power suspend mode, but still prevent the current connection from timing out.

Handbook of Mobile Communication Studies

Abstract: Mobile communication has become mainstream and even omnipresent. It is arguably the most successful and certainly the most rapidly adopted new technology in the world: more than one of every three people worldwide possesses a mobile phone. This volume offers a comprehensive view of the cultural, family, and interpersonal consequences of mobile communication across the globe. Leading scholars analyze the effect of mobile communication on all parts of life, from the relationship between literacy and the textual features of mobile phones to the use of ringtones as a form of social exchange, from the "aspirational consumption" of middle class families in India to the belief in parts of Africa and Asia that mobile phones can communicate with the dead. The contributors explore the ways mobile communication profoundly affects the tempo, structure, and process of daily life around the world. They discuss the impact of mobile communication on social networks, other communication strategies, traditional forms of social organization, and political activities. They consider how quickly miraculous technologies come to seem ordinary and even necessary--and how ordinary technology comes to seem mysterious and even miraculous. The chapters cut across social issues and geographical regions; they highlight use by the elite and the masses, utilitarian and expressive functions, and political and operational consequences. Taken together, the chapters demonstrate how mobile communication has affected the quality of life in both exotic and humdrum settings, and how it increasingly occupies center stage in peoples lives around the world.

Wireless relays for broadband access [radio communications series]

Abstract: This article presents the outlook of the overall broadband market and operators' challenges in offering profitable mass market mobile data services. The concept of wireless relaying and its state of the art are then introduced, followed by a comprehensive description of a multihop relay system for WiMAX and related use cases. The article explains the impact of relays on network planning and presents an example of deployment cost analysis in different traffic scenarios and propagation conditions. Performance results show that multihop relaying is one of the most promising technologies that enables cost-effective enhancement of coverage, user throughput, and system capacity, and is especially suitable for the emerging markets and rural areas.

WiMAX femtocells: a perspective on network architecture, capacity, and coverage

Abstract: Femtocells are viewed as a promising option for mobile operators to improve coverage and provide high-data-rate services in a cost-effective manner. The idea is to overlay low-power and low-cost base station devices, Femto-APs, on the existing cellular network, where each Femto-AP provides high-speed wireless connection to subscribers within a small range. In particular, Femto-APs can be used to serve indoor users, resulting in a powerful solution for ubiquitous indoor and outdoor coverage, using a single access technology such as WiMAX. In this article we consider a WiMAX network deploying both macro BSs and Femto-APs, where it is assumed that Femto-APs have wired backhaul such as cable or DSL and operate on the same frequency band as macro BSs. Simulation results show that significant areal capacity (throughput per unit area) gain can be achieved via intense spatial reuse of the wireless spectrum. In addition, Femto-APs improve indoor coverage, where the macro BS signal may be weak. Motivated by the gains in capacity and coverage offered by femtocells, we review the state of the art of this "infant" technology, including use cases and network deployment scenarios, technical challenges that need to be addressed, and current standardization and industry activity.

On effective offloading services for resource-constrained mobile devices running heavier mobile Internet applications

Abstract: Rapid advances in wireless mobile network technologies and mobile handsets (MHs) facilitate ubiquitous infrastructure that can support a range of mobile services and applications in addition to conventional mobile Internet access. One recent trend is to effectively run desktop PC-oriented heavier applications on MHs. However, due to their miniature, portable size, MHs are resource-constrained and therefore, running these applications directly on an MH is not satisfactory given a user's expectations. To cope with this problem, this article proposes a novel offloading service that can seamlessly offload some of the tasks of a mobile application from an MH to nearby, resource-rich PCs (called surrogates). The system architecture and key components of the proposed offloading service are presented, prototyped, and evaluated. The results of experiments and simulations have demonstrated the effectiveness and efficiency of this offloading service for mobile applications.

Mobile WiMAX systems: performance and evolution

Abstract: Mobile WiMAX was successfully adopted by ITU as one of the IMT-2000 technologies in November 2007. Since then mobile WiMAX (a.k.a. IP-OFDMA) has officially become a major global cellular wireless standard along with 3GPP UMTS/HSPA and 3GPP2 CDMA/ EVDO. Mobile WiMAX is an OFDM-based technology available for deployment today, and new WIMAX devices come to market at much reduced cost than that of current 3G solutions. Currently over 260 service providers are deploying fixed, portable and mobile WiMAX networks in 110 countries. This article provides an overview of the mobile WiMAX system and its performance under various configurations, channel conditions, and types of data traffic. Furthermore, the article provides an overview of mobile WiMAX evolution.

Speech recognition of speech recorded by a mobile communication facility

Abstract: In embodiments of the present invention improved capabilities are described for a mobile environment speech processing facility. The present invention may provide for the entering of text into a software application resident on a mobile communication facility, where recorded speech may be presented by the user using the mobile communications facility's resident capture facility. Transmission of the recording may be provided through a wireless communication facility to a speech recognition facility, and may be accompanied by information related to the software application. Results may be generated utilizing the speech recognition facility that may be independent of structured grammar, and may be based at least in part on the information relating to the software application and the recording. The results may then be transmitted to the mobile communications facility, where they may be loaded into the software application.

Interactive locked state mobile communication device

Abstract: A mobile communication device receives current information while the mobile communication device is in one of a sleep state or a locked state, and associates one or more portions of the current information with one or more corresponding windows. The mobile communication device also displays, via a display associated with the mobile communication device, the one or more corresponding windows and the one or more associated portions of the current information while the mobile communication device is in the locked state. The mobile communication device further enables a user associated with the mobile communication device to manipulate the one or more displayed corresponding windows while the mobile communication device is in the locked state.

Overview of mobile WiMAX technology and evolution

Abstract: Mobile WiMAX is a fast growing broadband access technology that enables low-cost mobile Internet applications, and realizes the convergence of mobile and fixed broadband access in a single air interface and network architecture. Mobile WiMAX combines OFDMA and advanced MIMO schemes along with flexible bandwidth and fast link adaptation, creating a highly efficient air interface that exceeds the capacity of existing and evolving 3G radio access networks. WiMAX networks, built on all-IP network architecture for plug and play network deployments, can support a mix of different usage and service models. While some consider mobile WiMAX as a candidate for the fourth generation of mobile networks, others view it as the first generation of mobile Internet technologies emerging from a wider ecosystem targeting to extend the success of WiFi over wide area networks supporting mobility. This article provides a high-level overview of mobile WiMAX technology and its evolution roadmap from both radio and network perspectives.

The role of mobile phones in sustainable rural poverty reduction

Abstract: Many developing country governments and developing agencies are focusing on extending telecommunications services into rural areas, as they seek to alleviate poverty, encourage economic and social growth, and overcome a perceived 'digital divide'. However, relatively little is known about how rural communities benefit from modern telecommunications services and what impact it is having on their lives and livelihoods. This paper endeavors to redress the balance, by examining the role of mobile telephones in sustainable poverty reduction among the rural poor. In the first section, the authors ask three questions: (a) Why are the rural poor important?; (b) What is information and why is it important?; and (c) Is the mobile telephone the most appropriate delivery mechanism for that information? In the second section, the authors look at the current status of the mobile industry in both the developed and developing world: (a) the authors consider the 'explosive' growth in availability and affordability of mobile phone services, which has been high in the developed world, but is gaining speed in the developing world; and (b) the authors examine the role of the private sector in this impressive growth. In the third section, the authors drill down into the impact of mobile telephony. The authors begin by examining the perceived correlation between GDP per capita and mobile penetration. Then the authors turn their attention to the examination of channels through which mobile phones benefit the rural poor: (a) direct benefits; (b) indirect benefits; and (c) intangible benefits, which contains an overview of hard-to-measure, rarely discussed but relevant, benefits of mobile telephony: namely, disaster relief, dissemination of locally-generated and locally-relevant educational and health information, and social capital or social cohesion. In the fourth section, the authors review several emerging global trends that may change the use and impact of mobile telephony in rural areas. Finally, the fifth section summarizes and interprets the main conclusions.

Mobile communication device monitoring systems and methods

Abstract: Systems and methods are directed to monitoring the communications to and from a mobile communication device in accordance with some embodiments of the present invention. For example in accordance with an embodiment, each of the data services on a mobile communication device may be monitored against rules stored in a central data center repository. The data services may include all forms of communications between the mobile communication device and a third party along with changes to application or data within the mobile communication device. An alert may be provided to an administrator when unauthorized data service activity and/or a message may be sent to the mobile communication device to prevent the unauthorized data service activity.

The Meandering Current Mobility Model and its Impact on Underwater Mobile Sensor Networks

Abstract: Underwater mobile acoustic sensor networks are promising tools for the exploration of the oceans. These networks require new robust solutions for fundamental issues such as: localization service for data tagging and networking protocols for communication. All these tasks are closely related with connectivity, coverage and deployment of the network. A realistic mobility model that can capture the physical movement of the sensor nodes with ocean currents gives better understanding on the above problems. In this paper, we propose a novel physically-inspired mobility model which is representative of underwater environments. We study how the model affects a range-based localization protocol, and its impact on the coverage and connectivity of the network under different deployment scenarios.

Distributed Deployment Schemes for Mobile Wireless Sensor Networks to Ensure Multilevel Coverage

Abstract: One of the research issues in wireless sensor networks (WSNs) is how to efficiently deploy sensors to cover an area. In this paper, we solve the k-coverage sensor deployment problem to achieve multi-level coverage of an area I. We consider two sub-problems: k-coverage placement and distributed dispatch problems. The placement problem asks how to determine the minimum number of sensors required and their locations in I to guarantee that I is k-covered and the network is connected; the dispatch problem asks how to schedule mobile sensors to move to the designated locations according to the result computed by the placement strategy such that the energy consumption due to movement is minimized. Our solutions to the placement problem consider both the binary and probabilistic sensing models, and allow an arbitrary relationship between the communication distance and sensing distance of sensors. For the dispatch problem, we propose a competition-based and a pattern-based schemes. The former allows mobile sensors to bid for their closest locations, while the latter allows sensors to derive the target locations on their own. Our proposed schemes are efficient in terms of the number of sensors required and are distributed in nature. Simulation results are presented to verify their effectiveness.

Using results of unstructured language model based speech recognition to control a system-level function of a mobile communications facility

Abstract: A user may control a mobile communication facility through recognized speech provided to the mobile communication facility. Speech that is recorded by a user using a mobile communication facility resident capture facility. A speech recognition facility generates results of the recorded speech using an unstructured language model based at least in part on information relating to the recording. A function of the operating system of the mobile communication facility is controlled based on the results.

Cross-layer design proposals for wireless mobile networks: a survey and taxonomy

Abstract: Third-generation (3G) and beyond 3G mobile communication systems must provide interoperability with the Internet, increase throughput for mobile devices, and optimize their operation for multimedia applications. The limited ability of traditional layered architectures to exploit the unique nature of wireless communication has fostered the introduction of cross-layer design solutions that allow optimized operation for mobile devices in the modern heterogeneous wireless environment. In this article we present the major cross-layer design solutions that handle such problems, and discuss cross-layer implementations with a focus on functional entities that support cross-layer processes and the respective signaling. In addition, we consider the associated architectural complexity and communication overhead they introduce. Furthermore, we point out the major open technical challenges in the cross-layer design research area. Finally, we conclude our article with a summary of cross-layer approaches developed thus far and provide directions for future work.

Method and system of providing event content sharing by mobile communication devices

Abstract: An approach is disclosed for providing sharing of content relating to an event. Detection of a plurality of mobile communication devices within a predetermined location is performed. An event is identified corresponding to the predetermined location and a current time. The mobile communication devices are notified to enable exchange of content about the event. The content is received from one or more of the mobile communication devices, wherein the content is accessible by the mobile communication devices.

Smart Home Mobile RFID-Based Internet-of-Things Systems and Services

Abstract: Smart homes can apply new Internet-Of-Things concepts along with RFID technologies for creating ubiquitous services. This paper introduces a novel read-out method for a hierarchical wireless master-slave RFID reader architecture of multi standard NFC (Near Field Communication) and UHF (Ultra High Frequency) technologies to build a smart home service system that benefits in terms of cost, energy consumption and complexity. Various smart home service use cases such as washing programs, cooking, shopping and elderly health care are described as examples that make use of this system.

An Augmented Reality museum guide

Abstract: Recent years have seen advances in many enabling augmented reality technologies. Furthermore, much research has been carried out on how augmented reality can be used to enhance existing applications. This paper describes our experiences with an AR-museum guide that combines some of the latest technologies. Amongst other technologies, markerless tracking, hybrid tracking, and an ultra-mobile-PC were used. Like existing audio guides, the AR-guide can be used by any museum visitor, during a six-month exhibition on Islamic art. We provide a detailed description of the museumpsilas motivation for using AR, of our experiences in developing the system, and the initial results of user surveys. Taking this information into account, we can derive possible system improvements.

System and method for providing routing, mapping, and relative position information to users of a communication network

Abstract: The present invention is directed to a system and method for providing real-time position information of one party to another party by utilizing a conventional telecommunication network system such as the convention telephone network, a mobile telecommunications network, a computer network, or the Internet. More specifically, the preferred embodiments of the present invention allow a caller and a receiver of a telephone call to provide to and receive from each other position information related to the caller and/or receiver's physical location, including address information, GPS coordinates, nearby fixed locations such as a parking structure, etc. Additionally, the preferred embodiments of the present invention allow a caller and receiver to retrieve routing instructions or maps for traveling to or from each other. In another embodiment of the present invention, a party may locate the position of another party via the entry of the other party's unique identifier such as a phone number of the other party's mobile phone. In yet another embodiment of the present invention, the position information of a party may be concurrently delivered to another party's computer terminal whereby the other party can process the information in further detail.

The impact of mobile telephony on developing country micro-enterprise: A nigerian case study

Abstract: Informational challenges---absence, uncertainty, asymmetry---shape the working of markets and commerce in many developing countries. For developing country micro-enterprises, which form the bulk of all enterprises worldwide, these challenges shape the characteristics of their supply chains. They reduce the chances that business and trade will emerge. They keep supply chains localised and intermediated. They make trade within those supply chains slow, costly, and risky. Mobile telephony may provide an opportunity to address the informational challenges and, hence, to alter the characteristics of trade within micro-enterprise supply chains. However, mobile telephony has only recently penetrated. This paper, therefore, presents one of the first case studies of the impact of mobile telephony on the numerically-dominant form of enterprise, based around a case study of the cloth-weaving sector in Nigeria. It finds that there are ways in which costs and risks are being reduced and time is saved, often by substitution of journeys. But it also finds a continuing need for journeys and physical meetings due to issues of trust, design intensity, physical inspection and exchange, and interaction complexity. As a result, there are few signs of the de-localisation or disintermediation predicted by some commentators. An economising effect of mobile phones on supply chain processes may therefore co-exist with the entrenchment of supply chain structures and a growing “competitive divide” between those with and without access to telephony.

Using speech recognition results based on an unstructured language model in a mobile communication facility application

Abstract: A method and system for entering information into a software application resident on a mobile communication facility is provided. The method and system may include recording speech presented by a user using a mobile communication facility resident capture facility, transmitting the recording through a wireless communication facility to a speech recognition facility, transmitting information relating to the software application to the speech recognition facility, generating results utilizing the speech recognition facility using an unstructured language model based at least in part on the information relating to the software application and the recording, transmitting the results to the mobile communications facility, loading the results into the software application and simultaneously displaying the results as a set of words and as a set of application results based on those words.

A Traveling Distance Prediction Based Method to Minimize Unnecessary Handovers from Cellular Networks to WLANs

Abstract: We propose a handover decision method based on the prediction of traveling distance within an IEEE 802.11 wireless local area network (WLAN) cell. The method uses two thresholds which are calculated by the mobile terminal (MT) as it enters the WLAN cell. The predicted traveling distance is compared against these thresholds to make a handover decision in order to minimize the probability of handover failures or unnecessary handovers from a cellular network to a WLAN. Our analysis shows that the proposed method successfully keeps the number of failed or unnecessary handovers low.