Location awareness

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Location awareness as a term in the context of topography has been extended to navigation using navigational instruments serving for the coordinates of the actual location of the bearer of a wireless communications entity in any wireless communications ambience.

Today the term applies to all kinds of navigating, real time locating and positioning support with global, regional or local scope of locating. Although it was originated as a communications technology term, it has also been applied to all fields of application of ubiquitous computing in business and consumer services especially in relation to traffic, logistics, business administration and leisure issues. Location awareness is supported by navigation systems, positioning systems and/or locating services.

Dey (2001) defines a context as any information that can be used to characterise the situation of entities. This definition may be specialised for location as a subset of context.[1]

History of terminology

The term has been originated for topology and configurations settings of network systems and sought to deal with of network entities. In this context network location awareness (NLA) service collects and stores network configuration and location information, and notifies applications when this information changes. The term has been newly redefined with mobile telecommunications of third generation (3GPP) of mobile networks, hence including both topologic and topographic context.

While the computer science community has initially perceived the context as a matter of user location, as Dey discussed in [1], in the last few years this notion has been considered not simply as a state, but part of a process in which users are involved. Thus, sophisticated and general context models have been proposed, always including location as a subset (see [2] for a updated survey), to support context-aware applications which use them to (a) adapt interfaces, (b) tailor the set of application-relevant data, (c) increase the precision of information retrieval, (d) discover services, (e) make the user interaction implicit, or (f) build smart environments. For example: A location aware mobile phone may know that it is currently in a building. This description is apart from the term of ‘’’context awareness’’’ as described in [3]

Cooperative and non cooperative locating

Location awareness is a term mainly in conjunction with cooperative locating systems. All qualities of non cooperative locating is generally understood as detection.

Quality assessment for cooperative locating systems

Locating becomes best effective with a qualified systems support and cooperation of a certain set of entities. There are certain qualities typical to each systems design. And there is a primary typization of class that applies to all systems:

  • Crisp locating offers a complete set of precisely measured distances, mainly with wireless or optical distance measurements or with additional phase angle measurements. Crisp locating is leading to a set of coordinates with best possible reference to a standardized system of coordinates, as e.g. WGS84 or just a plan of a building.
  • Real time locating offers a crisp locating with some requirements for timely delivery of results, especially for moving targets. Real time locating is defined with ISO/IEC 19762-5 and ISO/IEC 24730-1.[4]
  • Fuzzy locating offers an estimate for presence in qualified vicinity or in contiguity to a point of reference, mainly with wireless power level measurements to serve as a metrics for distance. Fuzzy locating does not claim for precision, but for distinction. Hence fuzzy locating is leading namely to a definition of membership in a local grouping or presence in a confinement or just existence in certain contiguity.
  • Various other locating offers an incomplete set of roughly measured distances, mainly with wireless distance measurements, leading to a set of coordinates primarily without exact reference to a standardized system of coordinates, but referring to a point of reference for example in polar coordinates (distance and direction).
  • Index locating just indicating the coincidence of a distinct label with a known location, as with fixed RFID readers and RFID tags. [5]

Quality of an offered system will frankly disclose its membership to one of these classes.

Location awareness and locating systems operation and usage

Location aware systems are concerned with the acquisition of coordinates in a well defined grid (for example using distance metrics and lateration algorithms to perceive a set of coordinates) or at least distances to reference points (for example discriminating presence at a certain choke point on a corridor or in a named room of a building). The abstraction and understanding of location (for example matching a set of measured distances to sufficient number of reference points as a defined location with a system of coordinates spanning a space or a surface), and application behaviour based on the recognized location (for example reporting measured location or guessed contiguity to points of control or surveillance)[6]

Navigation applications

Navigation and reckoning are key concerns for seafarers and pilots. The task is to dynamically determine the current location, the distance and direction to destination and the time to go. The inventing of RADAR served for ambient and regional demand and the NAVSTAR satellite systems for global demand. The current complacency with GPS and map based navigation aids (see for example Test Navigator [7]) in automobiles shows the persistent thrill of intelligence for locating on the move.

Surveying applications

Surveying is the static complement to navigating. This is the key concern for landownerss and architects and civil engineers since centuries. The current complacency with LASER triangulating aids (see for example Interessiert Sie weniger Aufwand? [8]) down to do-it-yourself qualities shows the persistent challenge for the intellect in locating perpendicluar and rectangular when constructing shelters of any quality.

Business process applications

Currently location awareness is applied to design innovative process controls, and is often used as an integral part of ubiquitous and wearable computing. It is also beginning to be felt in the Internet with the advent of location aware search results. However, location knowledge in itself does not generate benefit, but generally generates cost of communication. A wider scope of application must be envisaged, leading to context awareness. Schmidt, Beigl & Gellersen [9] define human factors and physical environment as two important aspects relating to computer science.

RTLS and RFID context

In the aftermath of the RFID hype (see for example Erste Ernüchterung[10]) reasonable assessing the operational needs led to the result, that identification of objects is necessary, but does not confirm availability of objects in the location of last identifying. In consequence, the determination of location is assessed as the additional need. However, it will take some time, to recognize that spontaneous locating is not the most economized approach. Instead, permanent location awareness provides the required status information [11]

Leisure and individuals context

Location awareness is regarded as an enabling technology for fostering sales of ubiquitous computing systems and 3GPP mobile phones. However, the presumed mandatory needs for such functionality long for proofing.

From a psychology point of view, location awareness carries the idea that individuals gain some additional self confidence with additional confirmation of current distinct whereabouts. Hence the individual should be aware of the origin or initial point and the destination or target location of current operation or motion. Social psychology, contexts of aging, and a contextual world view

Equipping for location awareness

Location awareness is enhanced with systems that provide location information. Generally, infrastructure may be required to obtain such information, but infrastructure is not mandatory

Location awareness without infrastructure

Such approach is logically limited to the cooperating entities in a contiguity. The longer the distance between the entities might be, the lesser informative will be the location information that is obtainable. The lack of references leads to relative metrics, which dissipates with increasing distances. In planar approaches the common use of artillery reckoning is required, for example with orienting North and referring to a known baseline.

Applications are known with avalanche rescue or emergency vacation and mountain rescue as well as with search and rescue, (SAR) and combat search and rescue, (CSAR). All approaches are combined with global positioning systems.

Examples for such solutions may apply concepts of RTLS and WPAN.

Location awareness with local infrastructure

This approach is equipped for example with local communications infrastructures, as WLAN or DECT. The location information obtained may be served in standardized coordinates as with floor plans or symbolic addresses, as room numbers. The information may be communicated in proprietary formats, as no standardization is yet available. The concepts mostly refer to cartesian coordinates bound to a chosen baseline or starting point. This approach applies for indoor usage and for short range outdoor usage limited with property confinements.

Location awareness with regional infrastructure

This approach is equipped with for example mobile phone systems, as 3GPP or GSM. The location information obtained may be served in standardized coordinates as with WGS84 and may be communicated in standardized formats, as with NMEA for outdoors usage of just in symbolic coordinates referring to built infrastructures of roads and buildings.

Location awareness with global infrastructure

This approach led to the current NAVSTAR and future Galileo deployments of satellite navigation support, or more generally, to the global positioning systems. The location information obtained is generally served in standardized coordinates as with WGS84 and communicated in statdardized formats, as with NMEA.

See also

  • Context adaptation
  • Context awareness
  • Context-aware pervasive systems
  • Differentiated service (design pattern)
  • Multilateration
  • Pager
  • Real time locating
  • Unilateration
  • LAMD


  1. 1.0 1.1 Dey, Anind K. (2001). "Understanding and Using Context". Personal Ubiquitous Computing 5 (1): 4–7. doi:10.1007/s007790170019. 
  2. Cristiana Bolchini and Carlo A. Curino and Elisa Quintarelli and Fabio A. Schreiber and Letizia Tanca (2007). "A data-oriented survey of context models" (PDF). SIGMOD Rec. (ACM) 36 (4): 19--26. doi:10.1145/1361348.1361353. ISSN 0163-5808. http://carlo.curino.us/documents/curino-context2007-survey.pdf. 
  3. Schmidt, A.; Aidoo, K.A.; Takaluoma, A.; Tuomela, U.; Van Laerhoven, K; Van de Velde W. (1999). "Advanced Interaction in Context" (PDF). 1st International Symposium on Handheld and Ubiquitous Computing (HUC99), Springer LNCS, Vol. 1707. pp. 89-101. 
  4. Malik, Ajay (2009), RTLS für Dummies, http://www.wiley-vch.de/publish/dt/books/forthcomingTitles/EE00/0-470-39868-X/?sID=2k2e8lg2r8ruf5ghork2ed46g1 
  5. Sweeney, Patrick (2006), RFID für Dummies, http://www.wiley-vch.de/publish/dt/books/bySubjectBA00/ISBN3-527-70263-6/?sID=lvkjcmj8ene7n5qci56q5gqsb3 
  6. Schmidt, Albrecht (2003). "Ubiquitous Computing - Computing in Context". PhD dissertation, Lancaster University.. 
  7. Test TomTom Navigator 6
  8. Das neue Messen
  9. Albrecht Schmidt, Michael Beigl and Hans-W. Gellersen (December 1999). "There is more to Context than Location" (PDF). Computers & Graphics Journal, Elsevier 23 (6): 893–902. http://www.teco.uni-karlsruhe.de/~albrecht/publication/draft_docs/context-is-more-than-location.pdf. 
  10. Fünf Jahre nach dem RFID-Hype erste Ernüchterung
  11. Rosemann, M., & Recker, J. (2006). "Context-aware process design: Exploring the extrinsic drivers for process flexibility". in T. Latour & M. Petit. 18th international conference on advanced information systems engineering. proceedings of workshops and doctoral consortium. Luxembourg: Namur University Press. pp. 149-158. 

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