M. Linsner GeoPriv Cisco Systems Internet Draft A. Thomson Intended status: Standard Track Cisco Systems Expires: September 2009 March 6, 2009 Campus/Building Relative Location for Civic Location Format draft-linsner-geopriv-relativeloc-03.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. 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The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on September 7, 2009. Linsner & Thomson Expires September 7, 2009 [Page 1] Internet-Draft Civic Relative Location March 2009 Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract This document defines additional civic address parameters for use in Location Objects [1], [2], and [4]. The format is based on the civic address definition of PIDF-LO. These additional parameters allow expression of a relative location within a building or campus. Table of Contents 1. Introduction...................................................2 2. Conventions used in this document..............................3 3. Additions to PIDF-LO...........................................4 4. Additions to DHCP Civic Location Option........................4 5. Relative Location..............................................4 5.1. Examples of the relative location parameters..............5 6. Security Considerations........................................6 7. IANA Considerations............................................7 7.1. XML Schema Registration...................................7 7.2. CAType Registry Update....................................7 8. References.....................................................7 8.1. Normative References......................................7 8.2. Informative References....................................7 9. Acknowledgments................................................7 1. Introduction Campus wireless LAN technologies are adding capabilities to locate serving hosts via radio frequency measurement technologies. This new capability is able to provide additional and more accurate location information when used inside a building, or on a campus in conjunction with civic addressing. The data produced from these technologies is most useful if expressed as relative position as opposed to expressing as a globally anchored geo location (latitude, Linsner & Thomson Expires September 7, 2009 [Page 2] Internet-Draft Civic Relative Location March 2009 longitude). Relative position dictates the expression of a civic anchor point within the confines of the building or campus (a starting point for measurement) hence providing both the relative position and relative location offset from the relative position is provided. The data included within the relative position parameters is supplementary to, not exclusive of, the existing civic location data expressed in PIDF-LO [1], [2] and DHCP Civic Location option [4]. An example of this may be a popular wireless hotspot located at 234 N. Main St. It is reasonable to expect that 234 N. Main St. covers a geographic area that encompasses several hundred square meters. The wireless network architecture for this hotspot could include several wireless infrastructure access points. The supplementary data provided via relative location would enable a more granular location expression. In addition to providing 234 N. Main St., a relative position like "6 meters south and 9 meters east of the main entrance" could be added. It is expected this supplementary civic location data will be used within the confines of the associated civic location and SHOULD not purposely be used to represent locations that are off-campus, or outside the boundary of the expressed civic address. It is recognized that RF signals do not stop at the civic address boundaries and in some cases the resultant location may fall outside the confines of the civic address. To address such cases, the reference point MUST be contained within the civic address and the resultant location SHOULD fall inside the boundaries of the civic address. In other words, using the cited example, providing a street address of 234 N. Main St. and then provide this relative location data that result in the location residing at another street address SHOULD not be allowed. Although [1] and [4] currently supports additional elements, like CAtypes 28 (room), 32 (additional code), or 33 (seat), results from the radio frequency measurement technologies are alternatives to these existing elements and in some cases the resultant location can be more accurate. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119 [1]. Linsner & Thomson Expires September 7, 2009 [Page 3] Internet-Draft Civic Relative Location March 2009 3. Additions to PIDF-LO PIDF-LO, as updated by [2], includes a full set of parameters used to describe civic locations. The new parameters defined here are additional to the updated set and provide a means to describe a host's civic location with added granularity. 4. Additions to DHCP Civic Location Option The new parameters defined here are additional and will update DHCP Civic Location Option [4] 5. Relative Location Relative location is defined by 2 new parameters, reference point and relative position. Reference point, similar to geodetic datum, defines the anchor point (0,0 point) used for measurement of the relative position parameter. Measurement from the anchor point is provided in 3 dimensions, X, Y and Z. The east-west dimension is labeled X and north-south dimension is labeled Y. A positive Y value is considered north of the reference point, a negative Y value south of the reference point, a positive X value for east of the reference point and a negative X value for west of the reference point. The measurement value is in meters. The fourth, height or altitude parameter (Z) found in normal geodetic systems can be optionally expressed via these new parameters but might be more useful converted to floor values and expressed in via CAtype 27, the FLR or Floor parameter, previously defined for [1] and [4]. If the altitude (Z) parameter is expressed, it is assumed to utilize locally significant ground level (the ground directly below the relative location) as the reference point from which to measure. For this usage, defining the reference point of local significance is completely subjective, but utilizing intuitively obviously locations, like 'Elevator', 'Exit Door', 'Stairwell' is suggested. As this mechanism is not intended for millimeter accuracy, human judgment will play in defining the measurement start point. Measurements SHOULD start at the center of the declared reference point. Linsner & Thomson Expires September 7, 2009 [Page 4] Internet-Draft Civic Relative Location March 2009 New Civic CAtype Description Example Field REFPT 40 Reference Point Elevator RELPOS-X 41 Relative Position X -12 RELPOS-Y 42 Relative Position Y 35 RELPOS-Z 43 Relative Position Z 60 optional Table 1: New Civic CAtypes 5.1. Examples of the relative location parameters A location that is 20 meters west and 31 meters south of elevator-1 elevator-1 -20 -31 A location that is 51 feet north and 23 feet east of the corner office corner_office 23 51 feet 5.1 Example Schema (ED note: schema needs review) Linsner & Thomson Expires September 7, 2009 [Page 5] Internet-Draft Civic Relative Location March 2009 6. Security Considerations The XML parameters defined in the document are additions to the current PIDF-LO specification. Therefore the parameters defined here are subject to the same security considerations of [1]. Linsner & Thomson Expires September 7, 2009 [Page 6] Internet-Draft Civic Relative Location March 2009 7. IANA Considerations 7.1. XML Schema Registration IANA will update the registered XML schema with additions as shown in section 5 of this document. URI: urn:ietf:params:xml:schema:pidf:geopriv10:civicAddr 7.2. CAType Registry Update IANA will update the civic address type registry established by RFC4776. The additions to the registry are shown in Table 1 of the document. 8. References 8.1. Normative References [1] Petersen, J., "A Presence-based GEOPRIV Location Object Format", RFC 4119, December 2005. [2] Thomson, M. & Winterbottom, J., "Revised Civic Location Format for Presence Identifier Format Location Object (PIDF-LO)", RFC 5139, February 2008. [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [4] Schulzrinne, H., "Dynamic Host Configuration Protocol (DHCPv4 and DHCPv6) Option for Civic Addresses Configuration Information", RFC4776, November 2006 8.2. Informative References There are no informative references at this time. 9. Acknowledgments The authors would like to acknowledge Henning Schulzrinne and Gabor Bajko for their extensive contributions to the draft. Linsner & Thomson Expires September 7, 2009 [Page 7] Internet-Draft Civic Relative Location March 2009 The authors would also like to thank Martin Thomson for his contributions to this draft. This document was prepared using 2-Word-v2.0.template.dot. Authors' Addresses Marc Linsner Cisco Systems, Inc. Marco Island, Florida, USA Email: mlinsner@cisco.com Allan Thomson Cisco Systems, Inc. San Jose, California, USA Email: althomso@cisco.com Linsner & Thomson Expires September 7, 2009 [Page 8]