INTERNET-DRAFT SPIRITS WG May 2002 Vijay K. Gurbani Expires: November 2002 Lucent Technologies, Inc. Daniel Moreno Vodafone Spain John Voelker Lucent Technologies, Inc. Document: draft-gurbani-spirits-location-00.txt SPIRITS Location Services STATUS OF THIS MEMO This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." 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. Abstract This document describes location- and mobility-related services as they are enabled by SPIRITS. SPIRITS services originate from certain actions occurring in the PSTN (wireline and wireless) and involve interactions with Internet hosts. The services described in this document pertain to location- and mobility-related events detected by the PSTN and reported to an Internet host which requested them for subsequent service execution. 1.0 Introduction The IETF SPIRITS WG is chartered with investigating how services supported by Internet hosts can be started from the Public Switched Telephone Network (PSTN). To that extent, the WG has produced an informational RFC [1] which details the SPIRITS architecture. Other draft-gurbani-spirits-location-00.txt [Page 1] SPIRITS Location Services. May 2002 relevant I-Ds to this I-D include the requirements of the SPIRITS protocol [2], the SPIRITS protocol itself [3], and mobility event management in SPIRITS [4] are under development. This document describes location-related services which are made possible by SPIRITS. For the remaining of the discussion in this I- D, we will assume that the term "PSTN" encompasses the wireless aspects of the circuit-switched network. Since the currently deployed worldwide wireless networks are based on circuit switching, they are considered PSTN networks for the SPIRITS purposes. Adding SPIRITS type of services to wireless networks can allow novel services to be developed. In the next section we define location-related events and discuss mobility- related events for Internet services. We note that mobility-related events can be considered as a subclass of location- related events. Section 3 provides some examples of services in the Internet domain which can be executed based on these events. Finally, section 4 identifies security and privacy concerns inherent in location services. 2.0 Location services Location services report or utilize the geographic location of the mobile station (MS). In typical wireless PSTN networks, a MS is associated with several PSTN entities. The cell site serving the MS contains a Mobile Switching Center (MSC), the wireless equivalent of a wireline Service Switching Point (SSP). The MSC is responsible for call processing and feature application. Associated with the MSC is a Home Location Register (HLR) and a Visitor Location Register (VLR). The HLR contains pertinent information about the user, including address, account status and feature preference. The VLR maintains temporary subscriber information (such as current location) to manage requests from subscribers who are visiting a foreign cellular network. Location of a MS can be obtained using Cell of Origin (COO) mobile positioning technique to identify a particular cell site that the MS is located in. However, since COO is not as precise, it can be augmented by other positioning technologies like Global Positioning System (GPS), Angle of Arrival (AOA) method, Time of Arrival Method (TOA), or a hybrid of any of these technolgies. Mobility-management events allow for an Internet host to be notified of changes in the location of a MS. Thus, we will consider these as a subset of location-related events. A mobility-management event occurs when a MS enters (or exits) a cell area being served by a particular MSC/VLR, or when an International Mobile Subscriber draft-gurbani-spirits-location-00.txt [Page 2] SPIRITS Location Services. May 2002 Identity (IMSI) attachment (or detachment) is detected. 3.0 Service examples This section contains SPIRITS service examples based on location and mobility- related events. This list is by no means exhaustive, but it is representative of such services and serves to catalog the ways in which such services are used. This I-D, in conjunction with [4] can be used as input to the SPIRITS protocol [3] for location- and mobility-based services. Readers are assumed to be familiar with [1,2,3] since the terms and concepts used in the examples are defined therein. (1) Short Message Service (SMS) and Instant Messaging: To use SMS as a SPIRITS service, an Internet host will subscribe to the appropriate DP in the PSTN that gets fired when an SMS event occurs. When the DP does get fired, an Instant Message will be sent out to the Internet host using the SIP MESSAGE extension [5]. (2) Mobility and Presence: A presence based system keeps track of presence- related attributes of a set of entities and disseminates this information to interested parties. The presence-related attributes may be quite coarse, as in "present", "not present"; or they may be fine grained, as in "away for 5 minutes", "away for the day", "present, but busy elsewhere", "invisible", etc. For a detailed treatment of presence, the interested reader is referred to [7, 8]. To use presence as a SPIRITS service, an Internet host will subscribe to a wireless registration event of a tel URL [9]. Whenever the wireless phone registers with the PSTN, the Internet host will be notified of this event. The presence system on the Internet host can update the presence status of the tel URL in a granularity defined by the application service provider. (3) Presence/3PCC services: Mobility and presence can be combined to provide a "callback" service to a mobile user from an Internet host in the following manner: Alice subscribes to the presence event of Bob with the intention of establishing a voice communication session with B. When the Internet host associated with Alice gets Bob's presence status, it uses SIP 3PCC [6] to establish a voice communication session with Bob. (4) Location-notification services: Many SPIRITS services can be triggered based on the location of a mobile station. For instance, a mobility event can be generated under all of the following conditions: draft-gurbani-spirits-location-00.txt [Page 3] SPIRITS Location Services. May 2002 (a) Location update in the same VLR service area (b) Location update in another VLR service area (c) IMSI attach (d) MS-initiated IMSI detach (e) Network-initiated IMSI detach Every time such a mobility event occurs, an Internet host can be notified. Some examples of SPIRITS services based on these events include: (a) Sending an Instant Message to an Internet host informing it of the location of the MS. This is extremely useful for tracking services, such as tracking the location of a delivery truck. (b) Updating geo-location presence status; for example, Alice is expecting Bob to arrive at her office for a conference. To that extent, she has subscribed to events in the wireless network that track Bob's MS as he travels towards Alice's office. When Alice notices that Bob is a short distance away from her office, she prepares to meet him at the front door. (c) Reporting the identity of every MS entering and leaving a service area. (d) Periodically receiving a count of MS entering and leaving a particular specified geographic area. 4.0 Security considerations Security and privacy concerns for SPIRITS related services are provided in [2,4]. This I-D does not present any other security threats besides those enumerated in [2,4]. AUTHORS' ADDRESSES Vijay K. Gurbani John Voelker Lucent Technologies, Inc. Lucent Technologies, Inc. 2000 Lucent Lane, Rm 6G-440 2000 Lucent Lane, Rm 2A-318 Naperville, Illinois 60566 Naperville, Illinois 60566 vkg@lucent.com jvoelker@lucent.com Daniel Moreno Buendia Vodafone Spain C/ Trespaderne, 29 Barajas-1 Building, 1st Floor 28042 MADRID SPAIN draft-gurbani-spirits-location-00.txt [Page 4] SPIRITS Location Services. May 2002 dmoreno@airtel.es ACRONYMS AOA Angle of Arrival COO Cell of Origin GPS Global Positioning System HLR Home Location Register IMSI International Mobile Subscriber Identity MS Mobile Station MSC Mobile Switching Center SMS Short Message Service SPIRITS Services in the PSTN/IN Requesting InTernet Services SSP Service Switching Point TOA Time of Arrival VLR Visitor Location Register Normative References: [1] L. Slutsman (Ed.), I. Faynberg, H-L. Lu, and M. Weissman, "The SPIRITS Architecture", IETF RFC 3136, June 2001, [2] I. Faynberg (Ed.), J. Gato, H-L. Lu, L. Slutsman, "SPIRITS Protocol Requirements", IETF Internet-Draft, Expires August 2002, Work in Progress, [3] V. Gurbani (Ed.), A. Brusilovsky, I. Faynberg, H-L. Lu, M. Unmehopa, K. Vemuri, and J. Gato, "The SPIRITS Protocol", IETF Internet-Draft, Expires October 2002, Work in Progress, [4] D. Moreno, "Mobility Event Management in SPIRITS", IETF Internet-Draft, Expires October 2002, Work in Progress, [5] B. Campbell, J. Rosenberg, H. Schulzrinne, C. Huitema, and D. Gurle, "Session Initiation Protocol Extension for Instant Messaging", IETF Internet-Draft, Expires November 2002, Work in Progress. [6] J. Rosenberg, J. Peterson, H. Schulzrinne, and G. Camarillo, "Best Current Practices for Third Party Call Control in the draft-gurbani-spirits-location-00.txt [Page 5] SPIRITS Location Services. May 2002 Session Initiation Protocol", IETF Internet-Draft, Expires November 2002, Work in Progress. Informative References [7] M. Day, J. Rosenberg, and H. Sugano, "A Model for Presence and Instant Messaging", IETF RFC 2778, February 2000. [8] J. Rosenberg, D. Willis, R. Sparks, B. Campbell, H. Schulzrinne, J. Lennox, C. Huitema, B. Aboba, D. Gurle, and D. Oran, "Session Initiation Protocol (SIP) Extensions for Presence", IETF Internet-Draft, Expires October 2002, Work in Progress. [9] A. Vaha-Sipila, "URLs for Telephone Calls", IETF RFC 2806, April 2000, FULL COPYRIGHT STATEMENT "Copyright (C) The Internet Society (date). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. 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