Location-based Systems Research Articles

TransportML platform for collaborative location-based services

Currently, each geographical area benefits from a set of wide range of local services, usually provided by several local entities, such as snow clearance, road works, public transportation, waste collection, fire fighting, emergency rescue authorities, etc. Despite each service fulfilling its own assigned task, they often suffer from a lack of communication and cooperation among them. Indeed, each service collects road-related information that may be useful to other services. Sharing information collected by each service would allow the acquisition of more knowledge about the driving context that may help drivers making appropriate decisions and, therefore, increase and improve road safety. Recently, wireless communication technologies associated with global navigation satellite systems and location-based information systems are among the powerful technologies used to develop interoperable intelligent transportation systems applications. Furthermore, the evolution of service-oriented infrastructures enables information sharing between applications over the network. In this paper, a distributed platform, called TransportML, for services interaction and cooperation is presented. It is an extended XML platform based on service-oriented architecture principles to recognize, monitor, and collect service information and description over a network. A prototype is developed and tested in urban and highway areas and results are reported to show the benefit of using this platform for sharing road information as well as services’ interactions.

Improving the Performance of a Topological Map-Matching Algorithm Through Error Detection and Correction

Map-matching algorithms integrate data from positioning sensors with a digital map in order, first, to identify the road link on which a vehicle is traveling, and second, to determine the vehicle's location on that link. Due to errors in positioning sensors, digital maps, and the map-matching (MM) process, MM algorithms sometimes fail to identify the correct road segment from the candidate segments. This phenomenon is known as mismatching. Identification of the wrong road link may mislead users and degrade the performance of a location-based intelligent transportation system (ITS) and services. The main objective of this article is to improve a topological map-matching (tMM) algorithm by error detection, correction, and performance re-evaluation. Errors in a tMM algorithm were determined using data comprising 62,887 positioning points collected in three different countries (the United Kingdom, the United States, and India). After map-matching, each mismatched case was examined to identify the primary causes of the mismatches. A number of strategies were developed and applied to reduce the risk of mismatching thus enhancing the tMM algorithm. An independent data set of 5,256 positioning points collected in and around Nottingham, UK, was employed to re-evaluate the performance of the enhanced tMM algorithm. The original tMM algorithm correctly identified the vehicle's position 96.5% of the time; after enhancement this increased to 97.8%. This compares very well with the performance of tMM algorithms reported in the literature. The enhanced tMM algorithm developed in this research is simple, fast, efficient, and easy to implement. Since the accuracy offered by the enhanced algorithm is found to be high, the developed algorithm has potential to be implemented in real-time location-based ITS applications.

실내 위치 인식 시스템에서 RF와 초음파 간섭 축소 기법

유비쿼터스 컴퓨팅 시대로 진입하면서 사물의 위치 정보가 더욱 중요시 되고 있다. 대표적인 실내 위치 인식 시스템인 크리켓은 노드 간의 거리를 인식하기 위해서 RF 신호와 초음파 신호를 주기적으로 전송한다. 하지만 배치되어 있는 센서 노드 수가 증가할수록 신호간의 간섭 및 충돌 횟수가 증가하여 위치 인식 시스템의 정확도를 떨어뜨린다. 본 논문에서는 초음파 위치인식 시스템을 구성하기 위해, 무선 센서 네트워크 표준인 IEEE 802.15.4 MAC 프로토콜을 사용하였다. 신호간의 간섭과 충돌 횟수를 감소시키기 위해, 노드 번호와 이동통신에서 사용하는 주파수 재사용 방식을 변형하여 오차율을 감소시키는 알고리즘을 제안하였다. 성능평가 결과 제안한 알고리즘이 기존의 크리켓시스템보다 수율과 에너지 효율 면에서 더 좋은 성능을 보였다. Location information is a critical element of ubiquitous computing. Cricket is an indoor location-based system that transmits radio and ultrasonic signals in regular intervals to calculate the distance between nodes. However, the amount of signal interference and collisions increases in proportion with the number of nodes, losing the accuracy of the location-based system. This study proposes an algorithm based on the 802.15.2 MAC protocol for the wireless sensor network to reduce signal interference and collision by employing node numbers and the frequency reuse approach used in mobile telecommunication. We analyzed the performance of our algorithm. The obtained results showed that the algorithm is an effective for throughput and energy compared to the Cricket system.

Development of Location-based Mobile Language Learning System to Support Geolearners

Supporting collaborative learning in relation to geographical location is becoming more prevalent for learners who are geographically connected (Geolearners). The advancement of mobile and ubiquitous computing enables determination of geographical location, supporting geolearners to collaborate and participate through Web 2.0 technologies. In this paper we describe the design and development of a system that facilitates location-based, situated and collaborative language learning, incorporating the potential of Internet-based television and mobile phones. We present TAMALLE+ (Television and Mobile phone Assisted Language Learning Environment), based on the requirements that were captured from multiple sources. Finally, we discuss results of multi-method evaluation studies together with further direction to our research.

Mobility-supporting data management for location-based mobile systems: the special case of single category location repositories

Location-based mobile applications require timely generation of user-centric proximities from application-relevant repositories of business locations. The proximity generation requirement is poorly served by conventional query resolution methods which are prone to response time degradation as repositories experience growth. This article reports research on a location-aware method (LAM) specifically devised to resolve queries for rapid proximity generation. Three operational concerns performance, scalability, and manageability provide a basis on which a specific form of LAM, linkcell-based LAM, is examined. Previous evaluative work on linkcell-based LAM focused on multiple category repositories (MCRs) in which business locations are explicitly classified using a predefined set of business categories. The research reported here concerns single category repositories (SCRs), an important special case in which no predefined set of business categories is used. Results show how a reformulated location-aware method may be used to manage SCRs and suggest the means by which scalability is achieved and proximity generation performance is optimised.

Exploiting Location and Contextual Information to Develop a Comprehensive Framework for Proactive Handover in Heterogeneous Environments

The development and deployment of several wireless and cellular networks mean that users will demand to be always connected as they move around. Mobile nodes will therefore have several interfaces and connections will be seamlessly switched among available networks using vertical handover techniques. Proactive handover mechanisms can be combined with the deployment of a number of location-based systems that provide location information to a very high degree of accuracy in different contexts. Furthermore, this new environment will also allow contextual information such as user profiles as well as the availability of using location and contextual information to provide efficient handover mechanisms. Using location-based techniques, it is possible to demonstrate that the Time Before Vertical Handover as well as the Network Dwell Time can be accurately estimated. These techniques are dependent on accurately estimating the handover radius. This paper investigates how location and context awareness can be used to estimate the best handover radius. The paper also explores how such techniques may be integrated into the Y-Comm architecture which is being used to explore the development of future mobile networks. Finally, the paper highlights the use of ontological techniques as a mechanism for specifying and prototyping such systems.

ITOHealth: a multimodal middleware-oriented integrated architecture for discovering medical entities

Emergency healthcare is one of the emerging application domains for information services, which requires highly multimodal information services. The time of consuming pre-hospital emergency process is critical. Therefore, the minimization of required time for providing primary care and consultation to patients is one of the crucial factors when trying to improve the healthcare delivery in emergency situations. In this sense, dynamic location of medical entities is a complex process that needs time and it can be critical when a person requires medical attention. This work presents a multimodal location-based system for locating and assigning medical entities called ITOHealth. ITOHealth provides a multimodal middleware-oriented integrated architecture using a service-oriented architecture in order to provide information of medical entities in mobile devices and web browsers with enriched interfaces providing multimodality support. ITOHealth's multimodality is based on the use of Microsoft Agent Characters, the integration of natural language voice to the characters, and multi-language and multi-characters support providing an advantage for users with visual impairments.

You are where you’ve been: the privacy implications of location and tracking technologies

A decade ago, technologies that could provide information about the location of a motor vehicle, or a computer or a person, were in their infancy. A wide range of tools, processes and systems are now in use and in prospect, which threaten to strip away another layer of the limited protections that individuals enjoy. An understanding of the landscape of location and tracking technologies, and of the issues that they give rise to, depends on establishing a specialist language that enables meaningful and reasonably unambiguous discussion to take place. An outline of the familiar case of mobile phones, complemented by deeper assessments of road tolling and the surveillance of individual motor vehicles on the road, provides a basis for appreciation of the substantial threats that location technologies represent to free society. This investigation describes location-based systems’ generic privacy threats, and identifies such specific threats as psychological harm, social harm, behavioural profiling, political harm and actual repression. Controls and protections are identified to counter these threats to privacy.

Pervasive Computer Games and Processes of Spatialization: Informational Territories and Mobile Technologies

Pervasive computer games (PCGs) combine digital mobile technologies and location-based systems by creating an interface between electronic and physical spaces for playing. PCG is a general name for mobile games such as hybrid reality games (HRGs), location-based mobile games (LBMGs), and urban games. Our goal here is to show how these games, along with new digital mobile technologies, have the potential to produce “spatialization,” i.e., to socially produce the space in which they are embedded. I suggest that spatialization is achieved through the use of technology such as sensors and digital mobile networks (smartphones, PDAs, global positioning systems [GPSs], and augmented reality [AR] devices; radio frequency identification [RFID] tags and global system for mobile communications/general packet radio service [GSM/GPRS]; Wi-Fi and Bluetooth). The goal of this article is to examine the forms of spatialization created by the use of location-based services and location-based technologies.

QuesTInSitu: From tests to routes for assessment in situ activities

Test-based assessment tools are mostly focused on the use of computers. However, advanced Information and Communication Technologies, such as handheld devices, opens up the possibilities of creating new assessment scenarios, increasing the teachers' choices to design more appropriate tests for their subject areas. In this paper we use the term Computing-Based Testing (CBT) instead of Computer-Based Testing, as it captures better the emerging trends. Within the CBT context, the paper is centered on proposing an approach for ''Assessment in situ'' activities, where questions have to be answered in front of a real space/location (situ). In particular, we present the QuesTInSitu software implementation that includes both an editor and a player based on the IMS Question and Test Interoperability specification and GoogleMaps. With QuesTInSitu teachers can create geolocated questions and tests (routes), and students can answer the tests using mobile devices with GPS when following a route. Three illustrating scenarios and the results from the implementation of one of them in a real educational situation show that QuesTInSitu enables the creation of innovative, enriched and context-aware assessment activities. The results also indicate that the use of mobile devices and location-based systems in assessment activities facilitates students to put explorative and spatial skills into practice and fosters their motivation, reflection and personal observation.

Accountabilities of Presence: Reframing Location-Based Systems

How do mobility and presence feature as aspects of social life? Using a case study of paroled offenders tracked via Global Positioning System (GPS), we explore the ways that location-based technologies frame people’s everyday experiences of space. In particular, we focus on how access and presence are negotiated outside of traditional conceptions of “privacy.” We introduce the notion of accountabilities of presence and suggest that it is a more useful concept than “privacy” for understanding the relationship between presence and sociality.

Robust road-to-car communications by means of an active Ku-band RF Self-IDentification (RFSID) system

This paper deals with a robust RFSID (Radio Frequency Self IDentification) system for road-to-car communications. The RFSID-based system operates in Ku-band and consists of a fixed transmitter, located at the road side, and of a receiver unit placed on the moving target, i.e. a car in its first proposed application. A slotted waveguide antenna array is used to illuminate the moving object at the desired position, whereas a four-patch array antenna is adopted at the receiver side. Both the antennas have been designed using numerical simulations based on a Finite Difference Time Domain (FDTD) algorithm. When the moving object crosses the antenna beam a triggering pulse is generated by the receiver; such a pulse can be used to reset or update the electronics aboard the vehicle and to log specific information coming from location-based systems (LBSs), into the car equipments. A digital transmission of gold sequences and a post-processing unit have been exploited so far to increase the robustness and the accuracy of the system. At this stage of the development the system benefit of extensive field tests, being adopted for some years by many top Formula 1 racing teams as a lap trigger system, used to reset the on-board electronics when the car crosses either the finishing line and peculiar path reference points. The temporal accuracy exhibited is better than 1 ms with a coverage of about 90 m.

Location-based push service system of tourism information

A push service system for location based tourism information was proposed by the combination of linear quad-tree,wireless network,Geographic Information System (GIS) and cross media techniques. GIS data was used as the spatial index in the interactive tourism information platform and guide subsystem. Other data such as text,image,audio and video were also used to model the scene at the same time. All types of those data were organized and managed through a cross-media model,thus the semantic relations among them were fully mined. This system obtains tourism information easily and pushes it in time,and is far more practical than other guide systems.

Location-based dynamic route guidance system of Korea: System design, algorithms and initial results

Over the last two years, the Korean Expressway Corporation (KEC) has developed a location-based dynamic route guidance system. The targets of the new system are the users of mobile-phones, the internet, and PDAs (Personal Digital Assistant), etc. Spatially the system covers 2,804 km of expressway and 484 km of national highway where the travel time collection systems are installed. The developed routing system is in many aspects different from the existing telematics-related services in Korea. It is based on predicted traffic information rather than real-time traffic information, and provides web and location based in-vehicle route guidance system. It utilizes GML (Geographical Markup Language) and GIS (Geographical Information System) in order to create GML DB (Data Base), and follows the standard format of the ISO (International Standard Organization) for GDF (Geographic Data File). Initial results of the proposed system including the accuracy of route travel time forecasts and the soundness of suggested routes were found to be acceptable. After development, the KEC has successfully tested a pilot service of the new system and is currently preparing for a full-scale implementation.

Enabling affordable and efficiently deployed location based smart home systems

With the obvious eldercare capabilities of smart environments it is a question of "when", rather than "if", these technologies will be routinely integrated into the design of future houses. In the meantime, health monitoring applications must be integrated into already complete home environments. However, there is significant effort involved in installing the hardware necessary to monitor the movements of an elder throughout an environment. Our work seeks to address the high infrastructure requirements of traditional location-based smart home systems by developing an extremely low infrastructure localisation technique. A study of the most efficient method of obtaining calibration data for an environment is conducted and different mobile devices are compared for localisation accuracy and cost trade-off. It is believed that these developments will contribute towards more efficiently deployed location-based smart home systems.

A context-aware computing methodology and development for mobile handhelds

This study discusses the design and implementation of a mobile handheld, which is applied to context-aware methodology of the location-based services (LBS) and global position system (GPS). During the analysis of the mobile handheld, an effective method was identified for the real-time processing of geographic information acquired by a camera attached to a personal data assistant (PDA) which is a newly developed mobile handheld. This study also discusses an experiment with a size of 320 times 240 pixels image, taken by an iPaq 3660 PDA, which has WinCE5.0 operating system and 512 MB RAM along with StrongARM 206 MHz.

Natural language processing for a location-based services system

A method and system for providing natural language processing in a communication system is disclosed. A voice request is generated with a remote terminal that is transmitted to a base station. A voice recognition application is then used to identify a plurality of words that are contained in the voice request. After the words are identified, a grammar associated with each word is also identified. Once the grammars have been identified, each word is categorized into a respective grammar category. A structured response is then generated to the voice request with a response generation application.

PhotoMap: from location and time to context-aware photo annotations

Despite the growth of geotagged multimedia data on the Web, spatial and temporal metadata are still poorly exploited by Web search engines and multimedia systems. Interpretation and inference processes can enlarge these metadata towards high quality information that are useful for annotating multimedia automatically. In this article, we propose a semi-automatic approach for annotating personal photos based on the use of OWL-DL ontologies together with the next generation of mobile devices. We present an ontology called ContextPhoto and a contextual photo annotation approach which improve the development of more efficient personal image management tools. ContextPhoto provides concepts for representing captured and inferred context information reusing Web standards that describe spatial, temporal and social networking data. In order to validate the context annotation process we propose, we have also designed and developed a mobile and Web location-based system. This new system, called PhotoMap, is an evolution of the related mobile annotation systems since it provides automatic annotation about the spatial, temporal and social contexts of a photo. We also present a demonstration of the PhotoMap application during a tourist tour in the city of Rome.

Comparative study of Extended Kalman Filter, Linearised Kalman Filter and Particle Filter applied to low-cost GPS-based hybrid positioning system for land vehicles

International research is very active in the topic of data fusion between GNSS and proprioceptive sensors to improve basic GNSS performances for advanced location-based aiding systems. In this frame, recursive Bayesian estimation methods, still are the most efficient and the most popular tools for measurement data fusion. This paper is to present comparisons, on the one hand between two very popular forms of the Kalman Filter: the so-called Linearized Kalman Filter (LKF), and the Extended Kalman Filter (EKF), and on the other hand between the Kalman Filter and one of its most promising challengers: the Particle Filter (PF). Experimental tests performed in two different circuits and discussion about comparative results are presented.

Implementation of a Prototype Positioning System for LBS on U-campus

Location-based service is one of the most popular buzzwords in the field of U-cities. Positioning a user is an essential ingredient of a location-based system in a U-city. For outdoor positioning, GPS based practical solutions have been introduced. However, the measurement error of GPS is too big for it to be used for U-campus services, because the size of a campus is smaller than that of a city. We propose the Relative-Interpolation Method to improve the accuracy of outdoor positioning. However, indoor positioning is also necessary for a U-campus because the GPS signal is not available inside buildings. For indoor positioning, various systems including Cricket, Active Badge, and so on have been introduced. These methods require special equipment dedicated to positioning. Our method does not require such equipment because it determines the user's position based on the received signal strength indicators (RSSIs) from access points (AP) which are already installed for WLAN. The algorithm we use for indoor positioning is a kind of fingerprinting method. However, our algorithm builds a decision tree instead of a look-up table in the off-line phase. Therefore, the proposed method is faster than the existing indoor positioning methods in the real-time phase. We integrated our indoor and outdoor positioning methods and implemented a prototype indoor-outdoor positioning system on a laptop. The experimental results are discussed in this paper. In implementing the prototype, we also implemented a C# library function which can be used to read the RSSIs from the APs.