Internet-Draft Daniel Moreno Document: draft-ietf-spirits-mobility-00.txt VODAFONE SPAIN April 2002 Expires: October 2002 Mobility Events Management in SPIRITS 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. This particular draft is intended to be discussed in the SPIRITS Working Group. Discussion of it therefore belongs on that list. The charter for SPIRITS working group may be found at http://www1.ietf.org/html.charters/spirits-charter.html. Abstract This document describes the management of the mobility events considered in SPIRITS protocol and the definition of their related parameters. The mobility events management will allow a SPIRITS server to subscribe to and to be notified of location changes of a mobile user. The events would only be applicable to mobile users reachable through a CS network. The sending of these events must be allowed by setting the related marks in the HLR. Besides, the SPIRITS protocol must be able to translate the CAMEL operations involving mobility information into events that can be transferred to the SPIRITS client. Moreno [Page 1]
Mobility Events Management in SPIRITS April 2002 Table of contents Status of this Memo...............................................1 Abstract..........................................................1 1. INTRODUCTION...................................................2 2. LIST OF MOBILITY EVENTS........................................2 3. LOCATION INFORMATION DESCRIPTION...............................3 3.1 CODING OF LOCATION INFORMATION ELEMENTS.......................4 3.1.1 Geographical Information....................................4 3.1.2 Age Of Location Information.................................5 3.1.3 CellId Or LAI...............................................5 3.1.4 location Number.............................................5 4. WIRELESS-SPECIFIC SECURITY CONSIDERATIONS ON MOBILITY MANAGEMENT ..................................................................5 5. XML DTDS FOR MOBILITY EVENTS...................................6 5.1 XML DTDS FOR NOTIFY...........................................6 5.2 XML DTDS FOR SUBSCRIBE.......................................11 6. REFERENCES....................................................11 7. AUTHOR'S ADRESS...............................................12 1. INTRODUCTION The mobility events management will allow a SPIRITS server to subscribe to and to be notified of location changes of a mobile user. The events would only be applicable to mobile users reachable through a CS network. The sending of these events must be allowed by setting the related marks in the HLR. Besides, the SPIRITS protocol must be able to translate the CAMEL operations involving mobility information into events that can be transferred to the SPIRITS client. The inclusion of mobility events into SPIRITS protocol provides user location information and allows the smart use of mobile phones in services like Internet Call Waiting. 2. LIST OF MOBILITY EVENTS The events considered in this document are: - Location Update in the same VLR service area - Location Update in another VLR service area - IMSI attach - MS initiated IMSI detach - Network initiated IMSI detach Moreno Expires - October 2002 [Page 2]
Mobility Events Management in SPIRITS April 2002 Every time a mobility event occurs, the subscribed SPIRITS servers will be notified about it, and they will receive the following information elements: - Event type. This IE indicates the type of Mobility Management that lead to the notification - Basic MSISDN of the mobile user. This IE identifies the mobile subscriber to whom the Mobility Event applies. - Location information. This IE indicates the current location of the MS. The first two parameters will be mandatory, and the last one will be optional, depending on the network capabilities. 3. LOCATION INFORMATION DESCRIPTION The Location information provided to the SPIRITS client would be very different depending on the mobile network capabilities, as not all the networks are able to supply detailed location information about its users. Therefore all the possible information elements considered into the location information must be marked as optional, and each network will try to make available as much information as possible. The compound information element Location information consists of the following subordinate information elements, all of them optional: - Location number This parameter is used to convey the geographical area address for mobility services. It is used when the calling Party Number does not contain any information about the geographical location of the calling party (for example, origin dependent routing when the calling party is a mobile subscriber). It can be present if the wireless network VLR can derive it from the stored service area identity (for UMTS) or cell global identity (for GSM) or location area identity; otherwise shall be absent. The mapping from service area identity or cell ID and location area to location number is network-specific, and the format is left open to final implementations. For a definition of this information element, see [1]. - Cell Id or Location Area ID Location area identity or Cell global identity of the cell in which the mobile user is currently in radio contact or in which the mobile user was last in radio contact. Will be present if the mobile user uses radio access and the subscriber record is marked as confirmed by radio contact; otherwise shall be absent. Moreno Expires - October 2002 [Page 3]
Mobility Events Management in SPIRITS April 2002 - Geographical information Will be present if the VLR can derive it from the stored cell global identity or location area identity; otherwise shall be absent (for a definition of this information element, see 3G TS 23.032). - Geodetic information Can be present if the VLR can derive it from the stored cell global identity or location area identity; otherwise shall be absent. (This information element corresponds to the Calling Geodetic Location defined in ITU-T Q.763). - Age of location information This parameter represents the elapsed time in minutes since the last network contact with the mobile user (i.e. the actuality of the location information). Will be present if available in the MSC/VLR; otherwise shall be absent. - Selected LSA Identity The IE shall only be sent, if SoLSA is supported. It indicates the LSA identity associated with the current position of the mobile user. Will be Sent if the LSA ID of subscription and LSA ID of the used cell matches. In the case of multiple matches the one with the highest priority is sent. See 3G TS 23.073. 3.1 CODING OF LOCATION INFORMATION ELEMENTS 3.1.1 Geographical Information The GeographicalInformation parameter refers to Geographical Information defined in GSM 03.32 Version 5.0.0. Only the description of an ellipsoid point with uncertainty circle as specified in GSM 03.32 is allowed to be used. The GeographicalInformation parameter contains the following sub- parameters: - TypeofShape Type of shape can only have the value of an ellipsoid point with uncertainty circle. - SignLAT: Sign of latitude 0 = North 1 = South - LAT is the latitude expressed in degrees (0-90) - LONG is the longitude expressed in degrees (0-360) Moreno Expires - October 2002 [Page 4]
Mobility Events Management in SPIRITS April 2002 - UncertaintyCode: K (exponent), defines the numerical representation of the radius R expressed in meters, where: K R = 10 ((1.1) - 1) 0 <= K <= 127 3.1.2 Age Of Location Information Usually coded as an integer (0..32767). The value represents the elapsed time in minutes since the last network contact of the mobile station. Some implementations define two special values: - value "0" indicates that the MS is currently in contact with the network - value "32767" indicates that the location information is at least 32767 minutes old 3.1.3 CellId Or LAI It is usually coded as a string. The Cell Global Identification is defined in TS GSM 03.03. The internal structure is not described here (Octets are coded according to TS GSM 04.08). 3.1.4 location Number It is usually coded as a string (length : 2 - 10 octets). The internal structure is not described here. 4. WIRELESS-SPECIFIC SECURITY CONSIDERATIONS ON MOBILITY MANAGEMENT The inclusion of mobility events management in SPIRITS protocol allows locating a mobile user and using this information into new services which can provide several advantages for IP users. But this feature can become also a security problem if a mobile user's location information is provided to non-authenticated applications or users. The location information must be treated with maximum care, and it must be guaranteed that no external parties will be able to get it in any way. For example, if an enterprise has a set of mobile users and an application over SPIRITS, which periodically provides their location information, there must be a way to authenticate the subscribing IP users (enterprise), in order to provide the information only to the right ones. On the other hand, the enterprise (SPIRITS server) will only be able to access to the information related to their own phones, and not to any other one that is not included into a related list of accessible phones. Moreno Expires - October 2002 [Page 5]
Mobility Events Management in SPIRITS April 2002 It is better to consider authentication and securing as matters to be implemented in the final applications. The security requirements must ensure that an IP user will not be allowed to subscribe to any notifications on mobile phones that are out of its control. This can be carried out by managing access control lists, whose definition is out the scope of this document. Another difficulty appears in case of connections from users that employ non-fixed IP addresses (i.e. GPRS connections from a mobile user), because those IP addresses couldn't be checked against a list of profiles. A possible alternative could be the inclusion of secret key-codes into every subscription request. These key-codes would be checked by the SPIRITS application before enabling notifications of mobility events about a certain mobile phone. This case is not included into this document, and it would imply adding a new parameter (access-code) into the "Subscribe XML DTD". This point is left open for future discussing. 5. XML DTDS FOR MOBILITY EVENTS This section presents XML DTDs for managing the mobility events and their related parameters. 5.1 XML DTDS FOR NOTIFY The next lines comprehend the DTD's for notifying a mobility event. The Event_met parameter can be considered as a subset of the complete events list. <!-- # Author: Daniel Moreno # Version: 1 # Organization: VODAFONE Spain # Date: 5/3/2002 --> <!-- ******************************************************************** ELEMENT: MM_event_notify COMMENT: root element that contains all the necessary parameters ******************************************************************** --> Moreno Expires - October 2002 [Page 6]
Mobility Events Management in SPIRITS April 2002 <!ELEMENT MM_event_notify ( Event_met , Basic_MSISDN , LocationInformation?) > <!-- ******************************************************************** ELEMENT: LocationInformation COMMENT: contains all the location parameters ******************************************************************** --> <!ELEMENT LocationInformation (LocationNumber?, CellIdOrLAI?, GeographicalInformation?, GeodeticInformation?, AgeOfLocationInformation?, LSAIdentity?) > <!-- ******************************************************************** ELEMENT: LSAIdentity COMMENT: content undefined ******************************************************************** --> <!ELEMENT LSAIdentity (#PCDATA) > <!-- ******************************************************************** ELEMENT: AgeOfLocationInformation COMMENT: USUALLY INTEGER (0..32767).Measured in minutes ******************************************************************** --> <!ELEMENT AgeOfLocationInformation (#PCDATA) > <!-- ******************************************************************** ELEMENT: GeodeticInformation COMMENT: This information element corresponds to the Calling Geodetic Location defined in ITU-T Q.763 ******************************************************************** --> <!ELEMENT GeodeticInformation (#PCDATA) > <!-- ******************************************************************** ELEMENT: GeographicalInformation COMMENT: For a definition of this information element, see 3G TS 23.032 ******************************************************************** --> Moreno Expires - October 2002 [Page 7]
Mobility Events Management in SPIRITS April 2002 <!ELEMENT GeographicalInformation (TypeOfShape, signLAT, LAT, LON, UncertaintyCode) > <!-- ******************************************************************** ELEMENT: UncertaintyCode COMMENT: values (0..127) ******************************************************************** --> <!ELEMENT UncertaintyCode (#PCDATA) > <!-- ******************************************************************** ELEMENT: LON COMMENT: In degrees (0..360) ******************************************************************** --> <!ELEMENT LON (#PCDATA) > <!-- ******************************************************************** ELEMENT: LAT COMMENT: In degrees (0..90) ******************************************************************** --> <!ELEMENT LAT (#PCDATA) > <!-- ******************************************************************** ELEMENT: signLAT COMMENT: ******************************************************************** --> <!ELEMENT signLAT (North|South) > <!-- ******************************************************************** ELEMENT: South COMMENT: ******************************************************************** --> <!ELEMENT South EMPTY > <!ATTLIST South South CDATA #FIXED "1" > Moreno Expires - October 2002 [Page 8]
Mobility Events Management in SPIRITS April 2002 <!-- ******************************************************************** ELEMENT: North COMMENT: ******************************************************************** --> <!ELEMENT North EMPTY > <!ATTLIST North North CDATA #FIXED "0" > <!-- ******************************************************************** ELEMENT: TypeOfShape COMMENT: 1 integer ******************************************************************** --> <!ELEMENT TypeOfShape (#PCDATA) > <!-- ******************************************************************** ELEMENT: CellIdOrLAI COMMENT: ******************************************************************** --> <!ELEMENT CellIdOrLAI (#PCDATA)> <!-- ******************************************************************** ELEMENT: LocationNumber COMMENT: length: 2-10 octets. Content will be passed unchanged. For a definition of this information element, see ITU-T Q.763 ******************************************************************** --> <!ELEMENT LocationNumber ( #PCDATA ) > <!-- ******************************************************************** ELEMENT: Basic_MSISDN COMMENT: MSISDN of the mobile user ******************************************************************** --> <!ELEMENT Basic_MSISDN (#PCDATA) > <!-- Moreno Expires - October 2002 [Page 9]
Mobility Events Management in SPIRITS April 2002 ******************************************************************** ELEMENT: Event_met COMMENT: Event type from list of possible values ******************************************************************** --> <!ELEMENT Event_met (LUS | LUA | IA | MSID | NID) > <!-- ******************************************************************** ELEMENT: NID COMMENT: Network initiated IMSI detach (implicit detach) ******************************************************************** --> <!ELEMENT NID EMPTY > <!-- ******************************************************************** ELEMENT: MSID COMMENT: MS initiated IMSI detach (explicit detach) ******************************************************************** --> <!ELEMENT MSID EMPTY > <!-- ******************************************************************** ELEMENT: IA COMMENT: IMSI attach ******************************************************************** --> <!ELEMENT IA EMPTY > <!-- ******************************************************************** ELEMENT: LUA COMMENT: Location update to another VLR service area ******************************************************************** --> <!ELEMENT LUA EMPTY > <!-- ******************************************************************** ELEMENT: LUS COMMENT: Location update in the same VLR service area ******************************************************************** Moreno Expires - October 2002 [Page 10]
Mobility Events Management in SPIRITS April 2002 --> <!ELEMENT LUS EMPTY > 5.2 XML DTDS FOR SUBSCRIBE The DTDs for subscribing to a mobility event could be like this (some of its elements are already defined in the notify section): <!-- # Author: Daniel Moreno # Version: 1 # Organisation: VODAFONE Spain # Date: 5/3/2002 --> <!-- ******************************************************************** ELEMENT: MM_event_subscribe COMMENT: root element that contains all the necessary parameters ******************************************************************** --> <!ELEMENT MM_event_ subscribe ( Event_met , Basic_MSISDN) > The DTDs for Event_met and Basic_MSISDN are the same as defined in section 5.1, so they are not included here. 6. REFERENCES [1] ITU-T Q.763, December 1999: "Specifications of Signalling System No. 7 û Formats and codes of the ISDN user part". [2] 3G TS 23.032, "Universal Geographical Area Description (GAD)". [3] 3G TS 23.073, "Support of Localised Service Area (SoLSA); Stage 2" [4] GSM 03.32 Version 5.0.0, " Digital cellular telecommunications system (Phase 2+) (GSM); Universal Geographical Area Description (GAD) " [5] TS GSM 03.03, " Digital cellular telecommunications system (Phase 2+) (GSM); Numbering, addressing and identification" [6] TS GSM 04.08, " Digital cellular telecommunications system (Phase 2+) (GSM); Mobile radio interface; Layer 3 specification" Moreno Expires - October 2002 [Page 11]
Mobility Events Management in SPIRITS April 2002 7. AUTHOR'S ADRESS Daniel Moreno Buendia Vodafone Spain C/ Trespaderne, 29 Barajas-1 Building, 1st Floor 28042 MADRID SPAIN email: dmoreno@airtel.es Phone number: +34610513410 Moreno Expires - October 2002 [Page 12]
