Internet Engineering Task Force (IETF) H. Schulzrinne
Request for Comments: 5962 V. Singh
Category: Standards Track Columbia University
ISSN: 2070-1721 H. Tschofenig
Nokia Siemens Networks
M. Thomson
Andrew Corporation
September 2010
Internet Engineering Task Force (IETF) H. Schulzrinne
Request for Comments: 5962 V. Singh
Category: Standards Track Columbia University
ISSN: 2070-1721 H. Tschofenig
Nokia Siemens Networks
M. Thomson
Andrew Corporation
September 2010
Dynamic Extensions to the Presence Information Data Format Location Object (PIDF-LO)
状态信息数据格式位置对象（PIDF-LO）的动态扩展
Abstract
摘要
The Geopriv Location Object introduced by the Presence Information Data Format - Location Object (PIDF-LO), RFC 4119, defines a basic XML format for carrying geographical information of a presentity. This document defines PIDF-LO extensions to convey information about moving objects. Elements are defined that enable expression of spatial orientation, speed, and heading of the presentity.
由存在信息数据格式-位置对象（PIDF-LO）RFC 4119引入的Geopriv位置对象定义了用于承载存在实体的地理信息的基本XML格式。本文档定义了PIDF-LO扩展以传递有关移动对象的信息。元素被定义为能够表达存在实体的空间方向、速度和方向。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见RFC 5741第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc5962.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc5962.
Copyright Notice
版权公告
Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2010 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction ....................................................2
2. Terminology .....................................................3
3. Dynamic Elements ................................................3
3.1. Angular Measures and Coordinate Reference Systems ..........5
4. Dynamic Feature XML Schema ......................................6
5. Security Considerations .........................................7
6. IANA Considerations .............................................7
6.1. Dynamic Feature Extensions Namespace Registration ..........7
6.2. Dynamic Feature Extensions Schema Registration .............8
7. Acknowledgements ................................................8
8. References ......................................................9
8.1. Normative References .......................................9
8.2. Informative References .....................................9
Appendix A. Earth Centered, Earth Fixed Direction Vectors ........10
1. Introduction ....................................................2
2. Terminology .....................................................3
3. Dynamic Elements ................................................3
3.1. Angular Measures and Coordinate Reference Systems ..........5
4. Dynamic Feature XML Schema ......................................6
5. Security Considerations .........................................7
6. IANA Considerations .............................................7
6.1. Dynamic Feature Extensions Namespace Registration ..........7
6.2. Dynamic Feature Extensions Schema Registration .............8
7. Acknowledgements ................................................8
8. References ......................................................9
8.1. Normative References .......................................9
8.2. Informative References .....................................9
Appendix A. Earth Centered, Earth Fixed Direction Vectors ........10
The Presence Information Data Format - Location Object (PIDF-LO) (see RFC 4119 [RFC4119]) provides geographical location of a presentity. This corresponds to a physical location at a given instance of time. RFC 5491 [RFC5491] extends PIDF-LO and provides additional guidelines to implementers.
存在信息数据格式-位置对象（PIDF-LO）（参见RFC 4119[RFC4119]）提供存在实体的地理位置。这对应于给定时间实例的物理位置。RFC 5491[RFC5491]扩展了PIDF-LO，并为实现者提供了额外的指南。
This document extends PIDF-LO to convey spatial orientation, speed, and heading of a presentity. The addition of rate-of-change information to the PIDF-LO enables a range of use cases. These use cases either use dynamic information directly or use that information
本文档扩展了PIDF-LO，以传达实体的空间方向、速度和航向。将变化率信息添加到PIDF-LO中可以实现一系列用例。这些用例要么直接使用动态信息，要么使用该信息
for smoother tracking of a position over time. For example, an application that continuously tracks a presentity could use velocity information to extrapolate positions in between times that location information is measured. A shipping company could directly use speed to monitor delivery truck speed to ensure speed limits are observed.
用于随时间平滑跟踪位置。例如，连续跟踪存在实体的应用程序可以使用速度信息在测量位置信息的时间间隔内推断位置。航运公司可以直接使用速度来监控送货卡车的速度，以确保遵守速度限制。
In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中的说明进行解释。
This document uses the term "presentity", as defined in RFC 2778 [RFC2778], to refer to the device subject to location determination. The similarity to presence concepts and the abstract location privacy architecture, as described in RFC 4079 [RFC4079], led to re-use of the Presence Information Data Format (PIDF) (see RFC 3863 [RFC3863]), and its enhancement for location information (see RFC 4119 [RFC4119]). Note that this document does not differentiate between human and non-human objects, and hence both are in scope.
本文件使用RFC 2778[RFC2778]中定义的术语“存在实体”来指代需要进行位置确定的设备。如RFC 4079[RFC4079]所述，与状态概念和抽象位置隐私架构的相似性导致了状态信息数据格式（PIDF）的重复使用（参见RFC 3863[RFC3863]），以及对位置信息的增强（参见RFC 4119[RFC4119]）。请注意，本文档不区分人类对象和非人类对象，因此两者都在范围内。
This document defines a new element, <Dynamic>, for the conveyance of dynamic information.
本文档定义了一个新元素，<Dynamic>，用于传递动态信息。
Dynamic information MAY be included without any other location information being present. When dynamic information is associated with information about the instantaneous position of the presentity, the <Dynamic> element MUST be included in the same <location-info> element as the corresponding geodetic (or civic) location information.
可以包括动态信息，而不存在任何其他位置信息。当动态信息与存在实体的瞬时位置相关联时，<dynamic>元素必须与相应的大地测量（或公民）位置信息包含在相同的<location info>元素中。
Dynamic information can be safely ignored by a recipient that does not support this specification. The <Dynamic> element contains the following components:
不支持此规范的收件人可以安全地忽略动态信息。<Dynamic>元素包含以下组件：
orientation:
方向：
The <orientation> element describes the spatial orientation of the presentity -- the direction that the object is pointing. For a device, this orientation might depend on the type of device. See Section 3.1 for details.
<orientation>元素描述存在实体的空间方向——对象指向的方向。对于设备，此方向可能取决于设备的类型。详见第3.1节。
speed:
速度：
Speed is the time rate of change in position of a presentity without regard for direction: the scalar component of velocity. The value for the <speed> element is a measure that is defined in meters per second.
速度是一个实体位置变化的时间速率，不考虑方向：速度的标量分量。<speed>元素的值是以米/秒为单位定义的度量值。
heading:
标题：
Heading is the directional component of velocity. See Section 3.1 for details.
航向是速度的方向分量。详见第3.1节。
Each element can be omitted if no information is available. In the following example, the presentity is approximately oriented to the North at a slightly elevated angle. The presentity is travelling 24 meters per second to the West:
如果没有可用信息，则可以省略每个元素。在下面的示例中，实体大致以略微升高的角度朝向北方。该实体以每秒24米的速度向西移动：
<?xml version="1.0" encoding="UTF-8"?>
<presence
xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
xmlns:dyn="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:gml="http://www.opengis.net/gml"
entity="pres:alice@example.com">
<dm:device id="abc123">
<gp:geopriv>
<gp:location-info>
<dyn:Dynamic>
<dyn:orientation>-3 12</dyn:orientation>
<dyn:speed>24</dyn:speed>
<dyn:heading>278</dyn:heading>
</dyn:Dynamic>
</gp:location-info>
<gp:usage-rules/>
<method>gps</method>
</gp:geopriv>
<timestamp>2009-06-22T20:57:29Z</timestamp>
<dm:deviceID>mac:1234567890ab</dm:deviceID>
</dm:device>
</presence>
<?xml version="1.0" encoding="UTF-8"?>
<presence
xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
xmlns:dyn="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:gml="http://www.opengis.net/gml"
entity="pres:alice@example.com">
<dm:device id="abc123">
<gp:geopriv>
<gp:location-info>
<dyn:Dynamic>
<dyn:orientation>-3 12</dyn:orientation>
<dyn:speed>24</dyn:speed>
<dyn:heading>278</dyn:heading>
</dyn:Dynamic>
</gp:location-info>
<gp:usage-rules/>
<method>gps</method>
</gp:geopriv>
<timestamp>2009-06-22T20:57:29Z</timestamp>
<dm:deviceID>mac:1234567890ab</dm:deviceID>
</dm:device>
</presence>
Another example shows a PIDF-LO document of the presentity alice@example.com on a bike travelling 12 meters per second. Her position is indicated as a circle. The values for speed may be used by a receiver to adjust the uncertainty over time.
另一个示例显示了存在实体的PIDF-LO文档alice@example.com骑自行车以每秒12米的速度行驶。她的位置用圆圈表示。接收器可使用速度值来调整随时间变化的不确定性。
<?xml version="1.0" encoding="UTF-8"?>
<presence
xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
xmlns:dyn="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:gml="http://www.opengis.net/gml"
xmlns:gs="http://www.opengis.net/pidflo/1.0"
entity="pres:alice@example.com">
<dm:device id="abc123">
<gp:geopriv>
<gp:location-info>
<gs:Circle srsName="urn:ogc:def:crs:EPSG::4326">
<gml:pos>42.5463 -73.2512</gml:pos>
<gs:radius uom="urn:ogc:def:uom:EPSG::9001">
100
</gs:radius>
</gs:Circle>
<dyn:Dynamic>
<dyn:speed>12</dyn:speed>
</dyn:Dynamic>
</gp:location-info>
<gp:usage-rules/>
<method>gps</method>
</gp:geopriv>
<timestamp>2009-06-22T20:57:29Z</timestamp>
<dm:deviceID>mac:1234567890ab</dm:deviceID>
</dm:device>
</presence>
<?xml version="1.0" encoding="UTF-8"?>
<presence
xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
xmlns:dyn="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:gml="http://www.opengis.net/gml"
xmlns:gs="http://www.opengis.net/pidflo/1.0"
entity="pres:alice@example.com">
<dm:device id="abc123">
<gp:geopriv>
<gp:location-info>
<gs:Circle srsName="urn:ogc:def:crs:EPSG::4326">
<gml:pos>42.5463 -73.2512</gml:pos>
<gs:radius uom="urn:ogc:def:uom:EPSG::9001">
100
</gs:radius>
</gs:Circle>
<dyn:Dynamic>
<dyn:speed>12</dyn:speed>
</dyn:Dynamic>
</gp:location-info>
<gp:usage-rules/>
<method>gps</method>
</gp:geopriv>
<timestamp>2009-06-22T20:57:29Z</timestamp>
<dm:deviceID>mac:1234567890ab</dm:deviceID>
</dm:device>
</presence>
[RFC5491] constrains the coordinate reference system (CRS) used in PIDF-LO to World Geodetic System 1984 (WGS 84), using either the two-dimensional (latitude, longitude) CRS identified by "urn:ogc:def:crs:EPSG::4326" or the three-dimensional (latitude, longitude, altitude) CRS identified by "urn:ogc:def:crs:EPSG::4979". Dynamic locations similarly assume that either of these coordinate reference systems will be used.
[RFC5491]使用“urn:ogc:def:CRS:EPSG:：4326”标识的二维（纬度、经度）坐标系或“urn:ogc:def:CRS:EPSG:：4979”标识的三维（纬度、经度、高度）坐标系，将PIDF-LO中使用的坐标系（CRS）约束为1984年世界大地测量系统（WGS 84）。动态位置同样假设将使用这些坐标系中的任何一个。
The <orientation> and <heading> elements both describe a direction.
The <orientation> element describes the "direction of facing"; the
<heading> element describes the "direction of travel". Both measures
The <orientation> and <heading> elements both describe a direction.
The <orientation> element describes the "direction of facing"; the
<heading> element describes the "direction of travel". Both measures
contain one or two angular values that are expressed relative to the current position of the presentity (see Appendix A). Angular measures are expressed in degrees, and values can be negative. If two measures are present, the values MUST be separated by whitespace.
包含一个或两个相对于实体当前位置表示的角度值（见附录A）。角度度量以度表示，值可以为负值。如果存在两个度量值，则值必须用空格分隔。
The first measure specifies the horizontal direction from the current position of the presentity to a point that it is pointing towards (for <orientation>) or travelling towards (for <heading>). Horizontal angles are measured from Northing to Easting. Horizontal angles start from zero when pointing to or travelling towards the North and increase towards the East.
第一个度量值指定了从实体当前位置到其指向（对于<orientation>）或向（对于<heading>）移动的点的水平方向。水平角从北向东测量。当指向或向北移动时，水平角从零开始，向东增加。
The second measure, if present, specifies the vertical component of this angle. This angle is the elevation from the local horizontal plane. If the second angle value is omitted, the vertical component is unknown. If only one angle is present, <orientation> describes only the horizontal component. For <heading>, the associated <speed> measure contains only the horizontal component of speed.
第二个度量值（如果存在）指定此角度的垂直分量。该角度是从局部水平平面的高程。如果忽略第二个角度值，则垂直分量未知。如果仅存在一个角度，<orientation>仅描述水平分量。对于<heading>，相关的<speed>度量值仅包含速度的水平分量。
<?xml version="1.0"?>
<xs:schema
targetNamespace="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:dyn="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<?xml version="1.0"?>
<xs:schema
targetNamespace="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:dyn="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:element name="Dynamic" type="dyn:dynamicType"/>
<xs:element name="Dynamic" type="dyn:dynamicType"/>
<xs:complexType name="dynamicType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="orientation" minOccurs="0"
type="dyn:directionType"/>
<xs:element name="speed" minOccurs="0"
type="xs:double"/>
<xs:element name="heading" minOccurs="0"
type="dyn:directionType"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="dynamicType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="orientation" minOccurs="0"
type="dyn:directionType"/>
<xs:element name="speed" minOccurs="0"
type="xs:double"/>
<xs:element name="heading" minOccurs="0"
type="dyn:directionType"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:simpleType name="directionType">
<xs:restriction base="dyn:doubleListType">
<xs:minLength value="1"/>
<xs:maxLength value="2"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="directionType">
<xs:restriction base="dyn:doubleListType">
<xs:minLength value="1"/>
<xs:maxLength value="2"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="doubleListType">
<xs:list itemType="xs:double"/>
</xs:simpleType>
<xs:simpleType name="doubleListType">
<xs:list itemType="xs:double"/>
</xs:simpleType>
</xs:schema>
</xs:schema>
This document defines additional location elements carried by PIDF-LO. These additional elements provide greater reason to observe the privacy and security considerations described in RFC 4119 [RFC4119]. No further privacy or security measures are necessary.
本文件定义了PIDF-LO携带的其他位置元素。这些附加元素为遵守RFC 4119[RFC4119]中所述的隐私和安全注意事项提供了更大的理由。无需采取进一步的隐私或安全措施。
RFC 4119 points back to RFC 3694 [RFC3694] and RFC 3693 [RFC3693] to describe the threat model and the security requirements imposed on the GEOPRIV architecture for sharing location information as a result of the threat model. It is important to note that these two documents often refer to threats related to the current location information of a presentity, while this document introduces dynamic information that may be used by attackers to anticipate the future location of a presentity. While already a series of location snapshots is likely to offer information for guessing the future location of a presentity, it has to be said that including more information in a PIDF-LO does increase the severity of an information leak. Those who deploy location-based services are in general strongly advised to provide their users with ways to control the distribution of location information to those who have been authorized to see it.
RFC 4119指向RFC 3694[RFC3694]和RFC 3693[RFC3693]，以描述威胁模型和GEOPRIV体系结构因威胁模型而共享位置信息的安全要求。需要注意的是，这两个文档通常涉及与实体当前位置信息相关的威胁，而该文档引入了动态信息，攻击者可以利用这些信息预测实体的未来位置。虽然已经有一系列位置快照可能提供猜测实体未来位置的信息，但必须指出，在PIDF-LO中包含更多信息确实会增加信息泄漏的严重性。一般而言，强烈建议部署基于位置的服务的用户向其用户提供方法，以控制将位置信息分发给有权查看位置信息的用户。
This section registers a new XML namespace (as described in [RFC3688]) and a new XML schema.
本节注册一个新的XML名称空间（如[RFC3688]中所述）和一个新的XML模式。
URI: urn:ietf:params:xml:ns:pidf:geopriv10:dynamic
URI: urn:ietf:params:xml:ns:pidf:geopriv10:dynamic
Registrant Contact: IETF Geopriv Working Group, Hannes Tschofenig (hannes.tschofenig@gmx.net).
注册人联系人：IETF Geopriv工作组，Hannes Tschofenig（Hannes。tschofenig@gmx.net).
XML:
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
"http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Dynamic Feature Extensions Namespace</title>
</head>
<body>
<h1>Namespace for Dynamic Feature Extensions to PIDF-LO</h1>
<h2>urn:ietf:params:xml:ns:pidf:geopriv10:dynamic</h2>
<p>See <a href=
"http://www.rfc-editor.org/rfc/rfc5962.txt"> RFC5962</a>.</p>
</body>
</html>
END
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
"http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Dynamic Feature Extensions Namespace</title>
</head>
<body>
<h1>Namespace for Dynamic Feature Extensions to PIDF-LO</h1>
<h2>urn:ietf:params:xml:ns:pidf:geopriv10:dynamic</h2>
<p>See <a href=
"http://www.rfc-editor.org/rfc/rfc5962.txt"> RFC5962</a>.</p>
</body>
</html>
END
URI: urn:ietf:params:xml:schema:pidf:dynamic
URI: urn:ietf:params:xml:schema:pidf:dynamic
Registrant Contact: IETF Geopriv Working Group, Hannes Tschofenig (hannes.tschofenig@gmx.net)
注册人联系人：IETF Geopriv工作组，Hannes Tschofenig（Hannes。tschofenig@gmx.net)
XML: The XML schema registered is contained in Section 4. Its first line is
XML：注册的XML模式包含在第4节中。它的第一行是
<?xml version="1.0"?>
<?xml version="1.0"?>
and its last line is
最后一行是
</xs:schema>
</xs:schema>
We would like to thank Klaus Darilion, Cullen Jennings, Rohan Mahy, Carl Reed, and Brian Rosen for their comments. Furthermore, we would like to thank Alexey Melnikov, Adrian Farrel, Tim Polk, Dan Romascanu for his IESG review comments, Avshalom Houri for his GenArt review, Hilarie Orman for her SECDIR review, and Joel Jaeggli for his Operations Directorate review.
我们要感谢克劳斯·达里翁、卡伦·詹宁斯、罗汉·马希、卡尔·里德和布赖恩·罗森的评论。此外，我们还要感谢Alexey Melnikov、Adrian Farrel、Tim Polk和Dan Romascanu的IESG审查意见、Avshalom Houri的GenArt审查意见、Hilarie Orman的SECDIR审查意见以及Joel Jaeggli的运营董事会审查意见。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004.
[RFC3688]Mealling，M.“IETF XML注册表”，BCP 81，RFC 3688，2004年1月。
[RFC4119] Peterson, J., "A Presence-based GEOPRIV Location Object Format", RFC 4119, December 2005.
[RFC4119]Peterson，J.，“一种基于状态的GEOPRIV定位对象格式”，RFC41192005年12月。
[RFC2778] Day, M., Rosenberg, J., and H. Sugano, "A Model for Presence and Instant Messaging", RFC 2778, February 2000.
[RFC2778]Day，M.，Rosenberg，J.，和H.Sugano，“状态和即时信息模型”，RFC 27782000年2月。
[RFC3693] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and J. Polk, "Geopriv Requirements", RFC 3693, February 2004.
[RFC3693]Cuellar，J.，Morris，J.，Mulligan，D.，Peterson，J.，和J.Polk，“地质驱动要求”，RFC 3693，2004年2月。
[RFC3694] Danley, M., Mulligan, D., Morris, J., and J. Peterson, "Threat Analysis of the Geopriv Protocol", RFC 3694, February 2004.
[RFC3694]Danley，M.，Mulligan，D.，Morris，J.，和J.Peterson，“Geopriv协议的威胁分析”，RFC 3694，2004年2月。
[RFC3863] Sugano, H., Fujimoto, S., Klyne, G., Bateman, A., Carr, W., and J. Peterson, "Presence Information Data Format (PIDF)", RFC 3863, August 2004.
[RFC3863]Sugano，H.，Fujimoto，S.，Klyne，G.，Batman，A.，Carr，W.，和J.Peterson，“状态信息数据格式（PIDF）”，RFC 38632004年8月。
[RFC4079] Peterson, J., "A Presence Architecture for the Distribution of GEOPRIV Location Objects", RFC 4079, July 2005.
[RFC4079]Peterson，J.，“GEOPRIV定位对象分布的存在架构”，RFC 4079，2005年7月。
[RFC5491] Winterbottom, J., Thomson, M., and H. Tschofenig, "GEOPRIV Presence Information Data Format Location Object (PIDF-LO) Usage Clarification, Considerations, and Recommendations", RFC 5491, March 2009.
[RFC5491]Winterbottom，J.，Thomson，M.，和H.Tschofenig，“GEOPRIV存在信息数据格式位置对象（PIDF-LO）使用说明、注意事项和建议”，RFC 54912009年3月。
Appendix A. Earth Centered, Earth Fixed Direction Vectors
附录A.地球中心、地球固定方向矢量
The absolute orientation or heading of a presentity depends on its latitude and longitude. The following vectors can be used to determine the absolute direction in the WGS 84 Earth Centered, Earth Fixed (X, Y, Z) coordinate space.
一个实体的绝对方位或航向取决于它的纬度和经度。以下矢量可用于确定WGS 84地球中心、地球固定（X、Y、Z）坐标空间中的绝对方向。
The direction of North as a unit vector in Earth Centered, Earth Fixed (ECEF) coordinates is:
在以地球为中心的固定地球（ECEF）坐标系中，以北为单位矢量的方向为：
North = [ -1 * sin(latitude) * cos(longitude),
-1 * sin(latitude) * sin(longitude),
cos(latitude) ]
North = [ -1 * sin(latitude) * cos(longitude),
-1 * sin(latitude) * sin(longitude),
cos(latitude) ]
The direction of "up" (the upward normal of the horizontal plane) as a unit vector in ECEF coordinates is:
在ECEF坐标中，作为单位矢量的“向上”（水平面的向上法线）方向为：
Up = [ cos(latitude) * cos(longitude),
cos(latitude) * sin(longitude),
sin(latitude) ]
Up = [ cos(latitude) * cos(longitude),
cos(latitude) * sin(longitude),
sin(latitude) ]
Authors' Addresses
作者地址
Henning Schulzrinne Columbia University Department of Computer Science 450 Computer Science Building New York, NY 10027 US
美国纽约州纽约市哥伦比亚大学计算机科学系计算机科学大楼450号
Phone: +1 212 939 7004
EMail: hgs@cs.columbia.edu
URI: http://www.cs.columbia.edu/
Phone: +1 212 939 7004
EMail: hgs@cs.columbia.edu
URI: http://www.cs.columbia.edu/
Vishal Singh Columbia University Department of Computer Science 450 Computer Science Building New York, NY 10027 US
Vishal Singh哥伦比亚大学计算机科学系450美国纽约州纽约市计算机科学大楼10027
EMail: vs2140@cs.columbia.edu
URI: http://www.cs.columbia.edu/~vs2140
EMail: vs2140@cs.columbia.edu
URI: http://www.cs.columbia.edu/~vs2140
Hannes Tschofenig Nokia Siemens Networks Linnoitustie 6 Espoo 02600 Finland
Hannes Tschofenig诺基亚西门子网络公司芬兰Linnoitustie 6 Espoo 02600
Phone: +358 (50) 4871445
EMail: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at/
Phone: +358 (50) 4871445
EMail: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at/
Martin Thomson Andrew Corporation Wollongong NSW Australia
澳大利亚新南威尔士州卧龙岗马丁·汤姆森·安德鲁公司
EMail: martin.thomson@andrew.com
EMail: martin.thomson@andrew.com