The growing commercial interest in indoor location-based services (ILBS) has spurred recent development of many indoor positioning techniques. Due to the absence of global positioning system (GPS) signal, many other signals have been proposed for indoor usage. Among them, Wi-Fi (802.11) emerges as a promising one due to the pervasive deployment of wireless LANs (WLANs). In particular, Wi-Fi fingerprinting has been attracting much attention recently because it does not require line-of-sight measurement of access points (APs) and achieves high applicability in complex indoor environment. This survey overviews recent advances on two major areas of Wi-Fi fingerprint localization: advanced localization techniques and efficient system deployment. Regarding advanced techniques to localize users, we present how to make use of temporal or spatial signal patterns, user collaboration, and motion sensors. Regarding efficient system deployment, we discuss recent advances on reducing offline labor-intensive survey, adapting to fingerprint changes, calibrating heterogeneous devices for signal collection, and achieving energy efficiency for smartphones. We study and compare the approaches through our deployment experiences, and discuss some future directions.

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Wi-Fi Fingerprint-Based Indoor Positioning: Recent Advances and Comparisons

We propose UnLoc, an unsupervised indoor localization scheme that bypasses the need for war-driving. Our key observation is that certain locations in an indoor environment present identifiable signatures on one or more sensing dimensions. An elevator, for instance, imposes a distinct pattern on a smartphone's accelerometer; a corridor-corner may overhear a unique set of WiFi access points; a specific spot may experience an unusual magnetic fluctuation. We hypothesize that these kind of signatures naturally exist in the environment, and can be envisioned as internal landmarks of a building. Mobile devices that "sense" these landmarks can recalibrate their locations, while dead-reckoning schemes can track them between landmarks. Results from 3 different indoor settings, including a shopping mall, demonstrate median location errors of 1:69m. War-driving is not necessary, neither are floorplans the system simultaneously computes the locations of users and landmarks, in a manner that they converge reasonably quickly. We believe this is an unconventional approach to indoor localization, holding promise for real-world deployment.

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No need to war-drive: unsupervised indoor localization

A home control and automation system and method. The system generally includes one or more wireless remote controls, a plurality of appliances (including network enabled appliances and traditional legacy appliances in the exemplary system), associated control centric devices, and associated content centric devices. Various methods for control and operation of appliances in the networked home control and automation environment are disclosed. Specifically, methods are disclosed which enable advanced home control features such as location based control setup and operation, network enabled legacy appliances and system integration, save and recall capabilities for appliance and media states, generic command based appliance controls, dynamic/complex macro command generation, and Internet based control capabilities from remote locations are disclosed in conjunction with the system of the current invention.

System and methods for home appliance identification and control in a networked environment

This survey summarizes almost 50 years of research and development in the field of Augmented Reality AR. From early research in the1960's until widespread availability by the 2010's there has been steady progress towards the goal of being able to seamlessly combine real and virtual worlds. We provide an overview of the common definitions of AR, and show how AR fits into taxonomies of other related technologies. A history of important milestones in Augmented Reality is followed by sections on the key enabling technologies of tracking, display and input devices. We also review design guidelines and provide some examples of successful AR applications. Finally, we conclude with a summary of directions for future work and a review of some of the areas that are currently being researched.

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A Survey of Augmented Reality

Location-based services (LBS) have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR) have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified based on specific sensor patterns in the environment, and this will be exploited in our proposed approach. In this work, we propose a sensor fusion framework for combining WiFi, PDR and landmarks. Since the whole system is running on a smartphone, which is resource limited, we formulate the sensor fusion problem in a linear perspective, then a Kalman filter is applied instead of a particle filter, which is widely used in the literature. Furthermore, novel techniques to enhance the accuracy of individual approaches are adopted. In the experiments, an Android app is developed for real-time indoor localization and navigation. A comparison has been made between our proposed approach and individual approaches. The results show significant improvement using our proposed framework. Our proposed system can provide an average localization accuracy of 1 m.

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Fusion of WiFi, Smartphone Sensors and Landmarks Using the Kalman Filter for Indoor Localization

This paper presents an aided dead-reckoning navigation structure and signal processing algorithms for self localization of an autonomous mobile device by fusing pedestrian dead reckoning and WiFi signal strength measurements. WiFi and inertial navigation systems (INS) are used for positioning and attitude determination in a wide range of applications. Over the last few years, a number of low-cost inertial sensors have become available. Although they exhibit large errors, WiFi measurements can be used to correct the drift weakening the navigation based on this technology. On the other hand, INS sensors can interact with the WiFi positioning system as they provide high-accuracy real-time navigation. A structure based on a Kalman filter and a particle filter is proposed. It fuses the heterogeneous information coming from those two independent technologies. Finally, the benefits of the proposed architecture are evaluated and compared with the pure WiFi and INS positioning systems.

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Advanced integration of WIFI and inertial navigation systems for indoor mobile positioning

The invention relates to a method of measuring a distance between two radio-communication devices (1, 2), consisting in measuring a radio signal exchange delay. According to the invention, the time-of-flight of the signals is calculated from the exchange delay and subsequently corrected using an analysis of a single channel measuring frame that is transmitted between the two devices. The corrected time-of-flight corresponds to the shortest propagation path followed by the radio signals. In the majority of radio transmission medium configurations, the corrected time-of-flight is a straight line measurement of the distance separating the two devices (1, 2).

Method of measuring a distance between two radio-communication devices and device adapted to implement one such method

Autant le GPS tend a s'imposer pour la localisation a l'exterieur des bâtiments, autant la situation est beaucoup plus ouverte pour la localisation a l'interieur des bâtiments De nombreux reseaux WiFi sont deployes dans les bâtiments Ils diffusent des informations de puissance du signal permettant de remonter a la position d'un mobile La technique du fingerprinting par puissance WiFi permet de localiser le mobile Cependant, l'utilisation de cette technique de localisation requiere une base de donnees correspondant a la couverture radio WiFi dans l'environnement L'utilisation d'une technique de localisation basee sur des mesures temporelles est moins contraignante que le fingerprinting L'emission d'impulsions radio tres breves confere a la technologie 802154a un fort pouvoir separateur des multi-trajets Le phenomene de multi-trajets est la principale contrainte au deploiement d'une technologie de localisation par mesures temporelles La detection du premier trajet est tres importante Des estimateurs comme le filtre de Kalman ou le filtre particulaire sont necessaires pour limiter les effets des multi-trajets, des bruits de mesure, etc Ces filtres peuvent aussi integrer des informations de cartographie Bien souvent, l'exploitation d'une seule technologie est insuffisante La fusion d'informations de localisation est une etape supplementaire pour ameliorer la localisation Des architectures de fusion robustes permettent de corriger les defauts de chacune des technologies pour conduire a un systeme plus robuste et plus precis en toutes circonstances Ce travail presente une approche innovante pour la localisation WiFi avec l'exploitation de cartographie dans l'estimateur tout en gardant une faible complexite suivant la plate-forme de deploiement visee L'exploration des capacites de la localisation par ULB est proposee dans un second temps, avant d'aborder une reflexion sur les methodes de fusion multi-capteurs

Techniques et technologies de localisation avancées pour terminaux mobiles dans les environnements indoor

The invention concerns a method for locating a terminal (10), equipped with inertial measuring means, in an environment (B) equipped with a plurality of telecommunication bases (12, 14, 16, 18) of a wireless local area network. Said method includes the following steps: measuring, from the terminal, the power levels received from the telecommunication bases, and delivering as position result, an identification of the point whereat the terminal is located, using the measured power levels and a reference database. The invention is characterized in that the method further includes: a step of filtering the delivered position result, taking into account inertial navigation data, and a correcting step which consists in correcting an inertial drift taking into account an overall trajectory of the terminal provided by said means filtering the delivered position result.

Method and device for locating a terminal in a wireless local area network

We present a platform and a set of position-adaptive basic services for indoor ambient intelligence environments. This suite of TM-based services implement various instances of implicit interaction based on the user’s position, mediated by a handheld personal device. An indoor navigation system has been implemented as a prototype application for a structured location-management infrastructure that maintains information about all fixed, movable and mobile features of the ambient environment, according to complementary abstract models of this space. Location and navigation information is presented to the user’s handheld device as a fully scalable, dynamic SVG scene. 802.11 fingerprinting is used as a basis for location-estimation at an inter-room scale, while RFID is used for close-range (intra-room) position detection.

Frederic Evennou

Papers

Advanced integration of WIFI and inertial navigation systems for indoor mobile positioning

Method of measuring a distance between two radio-communication devices and device adapted to implement one such method

Techniques et technologies de localisation avancées pour terminaux mobiles dans les environnements indoor

Method and device for locating a terminal in a wireless local area network

Position-Based Interaction for Indoor Ambient Intelligence Environments