Issues with LCI Date: 2010-05-09 Authors: January, 2010 November 2005 doc.: IEEE 802.11-06/0499r1 January, 2010 Issues with LCI Date: 2010-05-09 Authors: Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair <stuart.kerry@philips.com> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. Gabor Bajko

Original use cases Describe the location of an AP November 2005 doc.: IEEE 802.11-06/0499r1 May, 2010 Original use cases Describe the location of an AP Usually fixed or portable, but may be mobile as well Describe the location of a STA Mobile Definition of mobile: operates while in motion (changes location) Gabor Bajko

Location Encoding … is always preceded by location determination January, 2010 Location Encoding … is always preceded by location determination Location determination is the process when the location of an entity is measured and approximated It is not a deterministic procedure Results in an area where the subject is probably located (with a confidence level=95%) The resulted location is then encoded LCI aims to encode the probable location of an 802.11 entity Gabor Bajko

LCI LCI has been copy-pasted from RFC3825 and azimuth appended to it November 2005 doc.: IEEE 802.11-06/0499r1 January, 2010 LCI LCI has been copy-pasted from RFC3825 and azimuth appended to it RFC3825 uses a 9+25 bit fixed point number for WGS84 coordinates It can only be used to describe circles/ellipses with specific radiuses (34 values for Radius is allowed – k*2x with x=0 … 34) It can not be used to specify custom location boundaries: eg, it can not specify a location having latitude values [15.999 to 16.034], a full or partial arcband, a polygon, etc. See http://www.ietf.org/mail-archive/web/geopriv/current/msg05482.html and related discussion for further details Gabor Bajko

When does location determination result in an irregular shape? January, 2010 When does location determination result in an irregular shape? Yellow: coverage of APs Blue: probable location of the STA Green: smallest circle containing the blue area Purple: contour of the circle which can be encoded with LCI Result: STA location is anywhere within the external contour of the purple circle; much bigger area than the blue one Gabor Bajko

January, 2010 Proposal Define a new Location Measurement Request and Report (in addition to LCI) which uses: the encoding defined in RFC3825bis (binary) RFC3825bis can be used to describe a rectangle, or The encoding defined in RFC5194 (XML) RFC5194 encoding can be used to describe multiple type of shapes An irregular shape can always be approximated with a polygon It may not fit into an MPDU, fragmentation may be necessary Can use the fragmentation defined in 802.11u for GAS Responses to describe the geodetic location of a STA Gabor Bajko

November 2005 doc.: IEEE 802.11-06/0499r1 January, 2010 RFC3825bis It was agreed in IETF to make an update of RFC3825, for a limited applicability: the update will provide a means to describe a location in a form of a rectangle, by mostly reusing the fields defined in RFC3825 point Uncertainty X Uncertainty Y Gabor Bajko

Location encoding with RFC3825bis November 2005 doc.: IEEE 802.11-06/0499r1 January, 2010 Location encoding with RFC3825bis