Liu Y,Yang Z,Wang X et al.Location,localization,and localizability.JOURNAL OF COMPUTER SCIENCE AND TECHNOL0GY25(2):274-297Mar.2010 Location,Localization,and Localizability Yunhao Liu(刘云浩)，Member,.ACM,Senior Member,IEEE.Zheng Yang(杨铮)，Student Member,.ACM.IEEE Xiaoping Wang(王小平)，Student Member,IEEE,and Lirong Jian(简丽荣)，Student Member,,IEEE Department of Computer Science and Engineering,Hong Kong University of Science and Technology,Hong Kong,China E-mail:fliu,yangzh,xiaopingwang,jlrphx@cse.ust.hk Received October 28,2009;revised January 6,2010. Abstract Location-aware technology spawns numerous unforeseen pervasive applications in a wide range of living,pro- duction,commence,and public services.This article provides an overview of the location,localization,and localizability issues of wireless ad-hoc and sensor networks.Making data geographically meaningful,location information is essential for many applications,and it deeply aids a number of network functions,such as network routing,topology control,coverage, boundary detection,clustering,etc.We investigate a large body of existing localization approaches with focuses on error control and network localizability,the two rising aspects that attract significant research interests in recent years.Error control aims to alleviate the negative impact of noisy ranging measurement and the error accumulation effect during coope- rative localization process.Network localizability provides theoretical analysis on the performance of localization approaches, providing guidance on network configuration and adjustment.We emphasize the basic principles of localization to under- stand the state-of-the-art and to address directions of future research in the new and largely open areas of location-aware technologies. Keywords location-based services (LBS),localization,error control,localizability,wireless ad-hoc and sensor networks Location Indoor (Local) Indoor/Outdoor Outdoor(Global) Bluetooth GSM (2G) The proliferation of wireless and mobile devices has UWB WiFi ZigBee GPS fostered the demand for context-aware applications,in Intrared UMTS(3G) which location is viewed as one of the most signifi- Personal Wireless Wireles Telecommu Area Satellite cant contexts.For example,pervasive medical care WLAN Ad-H 15 nication Based Networks Nerwork Networks Nenworks is designed to accurately record and manage patient movements1-21;smart space enables the interaction be- Location-Based Services (LBS) tween physical space and human activities3-4;mod- ern logistics has major concerns on goods transporta- Fig.1.Location-based services for a wide range of wireless net- tion,inventory,and warehousing-6;environmental works. monitoring networks sense air,water,and soil quality and detect the source of pollutants in real timel7-11j. becomes critically essential and indispensable.The and mobile peer-to-peer computing encourages content overwhelming reason is that WSNs are fundamentally sharing and contributing among mobile hosts in the intended to provide information on spatial-temporal vicinity[12-13).In brief,location-based service (LBS) characteristics of the physical world;hence,it is impor- is a key enabling technology of these applications and tant to associate sensed data with locations,making widely exists in nowadays wireless communication net- data geographically meaningful.For example,a num- works from the short-range Bluetooth to the long-range ber of applications,such as object tracking and environ- telecommunication networks,as illustrated in Fig.1. ment monitoring,inherently rely on location informa- Recent technological advances have enabled the de- tion.A detailed survey on location-based applications velopment of low-cost,low-power,and multifunctional can be found in14-15. sensor devices.These nodes are autonomous devices Location information also supports many fundamen- with integrated sensing,processing,and communi- tal network services,including network routing,topol- cation capabilities.With the rapid development of ogy control,coverage,boundary detection,clustering, wireless sensor networks (WSNs).location information etc.We give a brief overview as follows. Survey C)2010 Springer Science+Business Media,LLC Science Press,ChinaLiu Y, Yang Z, Wang X et al. Location, localization, and localizability. JOURNAL OF COMPUTER SCIENCE AND TECHNOLOGY 25(2): 274–297 Mar. 2010 Location, Localization, and Localizability Yunhao Liu (刘云浩), Member, ACM, Senior Member, IEEE, Zheng Yang (杨 铮), Student Member, ACM, IEEE Xiaoping Wang (王小平), Student Member, IEEE, and Lirong Jian (简丽荣), Student Member, IEEE Department of Computer Science and Engineering, Hong Kong University of Science and Technology, Hong Kong, China E-mail: {liu, yangzh, xiaopingwang, jlrphx}@cse.ust.hk Received October 28, 2009; revised January 6, 2010. Abstract Location-aware technology spawns numerous unforeseen pervasive applications in a wide range of living, pro￾duction, commence, and public services. This article provides an overview of the location, localization, and localizability issues of wireless ad-hoc and sensor networks. Making data geographically meaningful, location information is essential for many applications, and it deeply aids a number of network functions, such as network routing, topology control, coverage, boundary detection, clustering, etc. We investigate a large body of existing localization approaches with focuses on error control and network localizability, the two rising aspects that attract significant research interests in recent years. Error control aims to alleviate the negative impact of noisy ranging measurement and the error accumulation effect during coope￾rative localization process. Network localizability provides theoretical analysis on the performance of localization approaches, providing guidance on network configuration and adjustment. We emphasize the basic principles of localization to under￾stand the state-of-the-art and to address directions of future research in the new and largely open areas of location-aware technologies. Keywords location-based services (LBS), localization, error control, localizability, wireless ad-hoc and sensor networks 1 Location The proliferation of wireless and mobile devices has fostered the demand for context-aware applications, in which location is viewed as one of the most signifi- cant contexts. For example, pervasive medical care is designed to accurately record and manage patient movements[1-2]; smart space enables the interaction be￾tween physical space and human activities[3-4]; mod￾ern logistics has major concerns on goods transporta￾tion, inventory, and warehousing[5-6]; environmental monitoring networks sense air, water, and soil quality and detect the source of pollutants in real time[7-11]; and mobile peer-to-peer computing encourages content sharing and contributing among mobile hosts in the vicinity[12-13]. In brief, location-based service (LBS) is a key enabling technology of these applications and widely exists in nowadays wireless communication net￾works from the short-range Bluetooth to the long-range telecommunication networks, as illustrated in Fig.1. Recent technological advances have enabled the de￾velopment of low-cost, low-power, and multifunctional sensor devices. These nodes are autonomous devices with integrated sensing, processing, and communi￾cation capabilities. With the rapid development of wireless sensor networks (WSNs), location information Fig.1. Location-based services for a wide range of wireless net￾works. becomes critically essential and indispensable. The overwhelming reason is that WSNs are fundamentally intended to provide information on spatial-temporal characteristics of the physical world; hence, it is impor￾tant to associate sensed data with locations, making data geographically meaningful. For example, a num￾ber of applications, such as object tracking and environ￾ment monitoring, inherently rely on location informa￾tion. A detailed survey on location-based applications can be found in [14-15]. Location information also supports many fundamen￾tal network services, including network routing, topol￾ogy control, coverage, boundary detection, clustering, etc. We give a brief overview as follows. Survey ©2010 Springer Science + Business Media, LLC & Science Press, China