1、 International Telecommunication Union ITU-T H.460.25TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (09/2010) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Supplementary services for multimedia Transport of geographic information in ITU-T H.323 systems Recommend
2、ation ITU-T H.460.25 ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS H.100H.199 INFRASTRUCTURE OF AUDIOVISUAL SERVICES General H.200H.219 Transmission multiplexing and synchronization H.220H.229 Systems aspects H.230H.239 Communication pr
3、ocedures H.240H.259 Coding of moving video H.260H.279 Related systems aspects H.280H.299 Systems and terminal equipment for audiovisual services H.300H.349 Directory services architecture for audiovisual and multimedia services H.350H.359 Quality of service architecture for audiovisual and multimedi
4、a services H.360H.369 Supplementary services for multimedia H.450H.499MOBILITY AND COLLABORATION PROCEDURES Overview of Mobility and Collaboration, definitions, protocols and procedures H.500H.509 Mobility for H-Series multimedia systems and services H.510H.519 Mobile multimedia collaboration applic
5、ations and services H.520H.529 Security for mobile multimedia systems and services H.530H.539 Security for mobile multimedia collaboration applications and services H.540H.549 Mobility interworking procedures H.550H.559 Mobile multimedia collaboration inter-working procedures H.560H.569 BROADBAND, T
6、RIPLE-PLAY AND ADVANCED MULTIMEDIA SERVICES Broadband multimedia services over VDSL H.610H.619 Advanced multimedia services and applications H.620H.629 IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV General aspects H.700H.719 IPTV terminal devices H.720H.729 IPTV middleware H.730H.739 IPTV appli
7、cation event handling H.740H.749 IPTV metadata H.750H.759 IPTV multimedia application frameworks H.760H.769 IPTV service discovery up to consumption H.770H.779 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T H.460.25 (09/2010) i Recommendation ITU-T H.460.25 Transp
8、ort of geographic information in ITU-T H.323 systems Summary Recommendation ITU-T H.460.25 defines a means of transmitting geographic information between two ITU-T H.323 entities. Geographic information may be either coordinate-based (i.e., longitude, latitude, and altitude) or civic addresses (e.g.
9、, country, city, and street address). History Edition Recommendation Approval Study Group 1.0 ITU-T H.460.25 2010-09-13 16 ii Rec. ITU-T H.460.25 (09/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, informatio
10、n and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwid
11、e basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA
12、Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administra
13、tion and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provision
14、s are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to th
15、e possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside o
16、f the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest
17、information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T H.460.25 (09/2010) iii CONTEN
18、TS Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations and acronyms 1 5 Conventions 2 6 General considerations 2 7 Capability advertisement 2 8 Encoding geographic information 3 9 Provision of geographic information by a gatekeeper 4 10 Provision of geographic information by an endpoint .
19、 5 11 Transmission of geographic information between endpoints . 5 Rec. ITU-T H.460.25 (09/2010) 1 Recommendation ITU-T H.460.25 Transport of geographic information in ITU-T H.323 systems 1 Scope This Recommendation defines a means of transmitting geographic information between two ITU-T H.323 entit
20、ies. Geographic information may be either coordinate-based (i.e., longitude, latitude, and altitude) or civic addresses (e.g., country, city, and street address). How an endpoint gets the coordinate or civic address information is not within the scope of this Recommendation. 2 References The followi
21、ng ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recomme
22、ndation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not gi
23、ve it, as a stand-alone document, the status of a Recommendation. ITU-T H.225.0 Recommendation ITU-T H.225.0 (2009), Call signalling protocols and media stream packetization for packet-based multimedia communication systems. ITU-T H.323 Recommendation ITU-T H.323 (2009), Packet-based multimedia comm
24、unications systems. IETF RFC 4119 IETF RFC 4119 (2005), A Presence-based GEOPRIV Location Object Format. IETF RFC 5139 IETF RFC 5139 (2008), Revised Civic Location Format for Presence Information Data Format Location Object (PIDF-LO). IETF RFC 5491 IETF RFC 5491 (2009), GEOPRIV Presence Information
25、Data Format Location Object (PIDF-LO) Usage Clarification, Considerations, and Recommendations. 3 Definitions None. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations: ACF Admissions Confirm ARQ Admissions Request GCF Gatekeeper Confirm GEF Generic Extensibility Framew
26、ork GPS Global Positioning System GRJ Gatekeeper Reject GRQ Gatekeeper Request LCF Location Confirm LRQ Location Request 2 Rec. ITU-T H.460.25 (09/2010) PIDF-LO Presence Information Data Format Location Object RAS Registration, Admission, and Status RCF Registration Confirm RRQ Registration Request
27、5 Conventions None. 6 General considerations Users of ITU-T H.323 multimedia communication systems might require transmission of geographic information to the called party or vice versa, or between an endpoint and its gatekeeper or any other ITU-T H.323 entity in the network. It might be used, as an
28、 example, by emergency personnel responding to a distress call or might be exchanged between friends in a social setting. The uses of geographic information are several and are not defined or constrained by this Recommendation. In some instances, a calling or called party may wish not to provide geo
29、graphic information to the other party or may wish to limit or restrict the use of that information. Such restrictions are taken care of by using the screening/presentation indicators. Transmission of geographic information to another entity is optional, and the user should be given some control ove
30、r when geographic information is conveyed. A device may advertise support for sending and receiving geographic information, but may choose not to transmit that information. A device may support the transmission of coordinate-based information, civic address information, or both. A gatekeeper may pro
31、vide an endpoint with geographic information via the RAS protocol. How the gatekeeper learns the user location information is outside the scope of this Recommendation. If the gatekeeper does not provide the endpoint with its geographic information, or if the endpoint prefers to override the informat
32、ion provided by the gatekeeper, the endpoint may use geographic information learned through user input, GPS input, or other sources. 7 Capability advertisement Endpoints capable of transmitting or receiving geographic information shall advertise that capability in the featureSet.supportedFeatures or
33、 supportedFeatures field of appropriate messages defined in ITU-T H.225.0, following the rules defined in clause 7.9 of ITU-T H.323, (“Generic Extensibility Framework“) and shall use this identifier when transmitting geographic information via the genericData parameter. Calling endpoint shall advert
34、ise this capability as a supported feature in call signalling messages, when needed or desired to transmit and/or receive the geographic information to/from called endpoint, respectively. Called endpoints that are capable of supporting geographic information shall advertise this capability in the re
35、sponse messages using the featureSet.supportedFeatures field. The geographic information capability is indicated with the feature identifier shown in Table 1. Rec. ITU-T H.460.25 (09/2010) 3 Table 1 Geographic Information feature Feature name: Geographic Information Feature description: This feature
36、 allows an ITU-T H.323 entity to transmit and/or receive geographic information to and/or from another ITU-T H.323 entity. Feature identifier type: Standard Feature identifier value: 25 Parameters associated with the advertisement of this capability are specified in the following clause. In consider
37、ation of backward compatibility with further revisions to this Recommendation, the recipient shall ignore any parameters received other than those specified in this Recommendation. 8 Encoding geographic information When transmitting geographic information, the ITU-T H.323 entity shall include the in
38、formation in a genericData SEQUENCE in any of the messages discussed in clauses 7, 8 and 9. The geographic information shall be encoded as per Tables 2 to 6. More than one location information element can be sent in a PIDF-LO. The guidelines to be followed when creating a PIDF-LO with multiple locat
39、ion information are the same as those specified in IETF RFC 5491. If an entity wishes to revoke the previously transmitted geographic information, it shall send a message containing the Location parameter having an absent content field. Table 2 Location Parameter name: Location Parameter description
40、: Indicates the geographic location in the form of an XML-defined PIDF-LO object, IETF RFC 4119 and IETF RFC 5139. Parameter identifier type: Standard Parameter identifier value: 1 Parameter type: raw Parameter cardinality: One or more. When the call is routed through an ITU-T H.323 entity (e.g., a
41、gatekeeper that routes call signalling), the ITU-T H.323 entity may provide a screening service that indicates whether the location details were provided by the user or the intermediate ITU-T H.323 entities along the signalling path and whether the location was screened by an ITU-T H.323 entity. Pre
42、sentation indicator allows the ITU-T H.323 entity to restrict or allow the presentation of the Location parameter to the other entity in a call. Table 3 Screening Indicator Parameter name: Screening Indicator Parameter description: Indicates whether the location details were provided by the user or
43、by the intermediate ITU-T H.323 entity and whether the location was screened by the entity. Parameter identifier type: Standard Parameter identifier value: 2 Parameter type: number8 Parameter cardinality: Once for every location parameter. 4 Rec. ITU-T H.460.25 (09/2010) Table 4 Screening Indicator
44、values Value Meaning 0 userProvidedNotScreened: Location info was provided by the user and has not been screened by any ITU-T H.323 entity. 1 userProvidedVerifiedAndPassed: Location info was provided by the user or by a remote network, it has been screened by an ITU-T H.323 entity and passed verific
45、ation. 2 userProvidedVerifiedAndFailed: Location info was provided by the user or by a remote network, but an ITU-T H.323 entity has determined that the information is incorrect. 3 networkProvided: Location info was provided by an ITU-T H.323 entity. Table 5 Presentation Indicator Parameter name: Pr
46、esentation Indicator Parameter description: Indicates whether presentation of the Location should be allowed or restricted. Parameter identifier type: Standard Parameter identifier value: 3 Parameter type: number8 Parameter cardinality: Once for every location parameter. Table 6 Presentation Indicat
47、or values Value Meaning 0 PresentationAllowed 1 PresentationRestricted 9 Provision of geographic information by a gatekeeper A gatekeeper may provide geographic information to an endpoint that has advertised support for this Recommendation by including the Location parameter in the RCF message. A ga
48、tekeeper may include the users geographic location information in the LRQ message. The gatekeeper may also provide the called entitys geographic information in the LCF. A gatekeeper that receives the location information in the LCF should provide the same in the ACF response to the user. A gatekeepe
49、r that resolves the called endpoint location by itself may include the geographic location in ACF. The endpoint may accept and use the provided geographic information, or it may override it using the geographic information it has learned through other sources, such as user input, GPS, or other input sources. The alternative input sources are outside the scope of this Recommendation. Rec. ITU-T H.460.25 (09/2010) 5 10 Provision of geographic information by an endpoint An endpoint willing to provide its location informat
