Internet DRAFT - draft-wang-xmpp-extension
draft-wang-xmpp-extension
XMPP P. Wang
Internet Draft H. Wang
Interned status: Standards Track F. Lan
Expires: April 2, 2013 Chongqing University of
Posts and Telecommunicatis
C. Zhou
Cisco Systems
October 2, 2012
XMPP Extension Protocol for the Internet of Things
draft-wang-xmpp-extension-00.txt
Abstract
This document defines the xmpp extension protocol for wireless sensor
networks. Such as industrial automation process control and smart
home applications, etc. This protocol provided the methods of
interaction among applications.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute working
documents as Internet-Drafts. The list of current Internet-Drafts is
at http://datatracker.ietf.org/drafts/current/.
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."
This Internet-Draft will expire on April 2, 2013.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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
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Legal Provisions and are provided without warranty as described in
the Simplified BSD License.
Table of Contents
1. Introduction.................................................3
1.1. Overview................................................3
1.2. Terminology.............................................3
2. Requirements.................................................3
3. Object-oriented model........................................4
3.1. Overview................................................4
3.2. Object concept..........................................4
3.3. Object definition.......................................5
3.3.1. Device management object...........................5
3.3.2. Alarm object.......................................7
3.3.3. User object........................................8
3.4. Methods................................................13
3.4.1. Public methods....................................13
3.4.2. Private methods...................................14
3.4.3. Client/Server communication mode..................14
3.4.4. Publish/Subscribe communication mode..............15
3.4.5. Source/Sink communication mode....................16
4. Protocol....................................................16
4.1. Syntax.................................................16
4.2. Element................................................17
4.3. Communicated processing examples.......................19
5. Security Considerations.....................................26
6. IANA Considerations.........................................26
7. References..................................................26
7.1. Normative References...................................26
7.2. Informative References.................................27
Appendix A. XML Schema.........................................27
Authors' Addresses.............................................30
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1. Introduction
1.1. Overview
Wireless sensor network contains many kinds of applications, such as
intelligent transportation, industrial monitoring, green agriculture,
environmental monitoring or public safety. There are also many
protocols for the application of wireless sensor network, in which
there exists many problems, such as for compatibility or
interoperability. This document provides a generic protocol framework
which could be extended for the applications. Because of the
diversity of wireless sensor network, this document defined software
objects to model real-world objects with concept of object-oriented,
and defined the communication between object to object.
1.2. Terminology
Many important terms used in this document are defined in [FRAMEWORK],
[I18N-TERMS], [IDNA-DEFS], [UNICODE], and [XMPP].
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC 2119].
2. Requirements
This document shall reach the following requirements.
Transporting monitor data in real-time, which is the typical task of
WSN, protocol should submit the real-time data of data submit entity
(sensor node in general) to data handle entity (server, client which
is controlled by human or intelligent execute device).
Alarm, WSN should have ability to report the emergencies or abnormal
events to monitor device.
Portability, protocol should define general data format or basic data
type.
Lightweight, WSN node is resource limited node, RAM and ROM of node
are generally relatively small, and the process resource is limited,
so the protocol must have the lightweight characteristics.
Flexibility, protocol should have the function of flexible and
scalable.
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Compatibility, protocol should only define the extension of the
existing XMPP protocol, and it should be also compatible with
existing implementation.
3. Object-oriented model
3.1. Overview
An object model is a protocol, platform, and language-neutral means
of describing and distinguishing components (system elements) that
have a unique identity. Objects separate the world into meaningful
and manageable pieces. Not only do object definitions promote
modularity, but also promote component reusability. An object can
represent anything that has state and behavior. Object expose
attributes to represent state, and provide methods that operate on
the objects state to affect particular behaviors.
3.2. Object concept
An object encapsulates attributes and methods. Attribute presents the
characteristic of object, and method is an interface function or
functions module to access object. The definition of object can be
defined by different functions, functions module technology or other
methods.
From the user point of view, communication occurs from one object in
an application to another object in an application. Each of
application may contain multiple objects. It enables this protocol
can meet the need of specific market, such as for industries process
or factory automation. Figure 1 depicts the applications structure of
object-oriented.
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+----------------------------------------------+
| +-------------------------------+|
| | +----------+ +----------+ ||
| Application | | object 1 | ... | object n | ||
| | +----------+ +----------+ ||
| +-------------------------------+|
| / \ |
| | | |
| | | |
| \ / |
| +-------------------------------+|
| | ||
| Lower layer | Transport layer ||
| | ||
| +-------------------------------+|
+----------------------------------------------+
Figure 1 Applications structure of object-oriented
Object uses object ID to addressing, object ID should be unique in a
device. In this document, regard the object name as the unique
identifier. It enables lower layer can route messages to right
destination object. Parse of each message can be realized by
destination object, and take action to it according to the message.
This protocol defined the object name of standard.
3.3. Object definition
It uses the methods of object-oriented to defining object in this
document. Objects have their own attributes and methods, the content
of definition contains object name, attribute name, attribute data
type and supported methods.
3.3.1. Device management object
Device management object (DMO) provided management functions of local
device, it realized device management functions with accessing the
object' attribute and calling the methods of object. Attribute which
included in the object may be used in all practicable devices. Device
manufacturers may extend it based on existing status. Table 1
describes the device management object attributes. About the
supported methods, see 4.4.1.
Table 1 DMO attributes
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+-------------------------------------------------------------------+
| Attribute |Data type|Supported| Description |
| name | | methods | |
|-------------------------------------------------------------------|
| DMO | string | - | Object name |
|-------------------------------------------------------------------|
| Vender ID | string | read | Manufacturer name, |
| | | | designated by manufacturer |
|-------------------------------------------------------------------|
| Serial | string | read | Number, |
| Number | | | designated by manufacturer |
|-------------------------------------------------------------------|
|Power Supply|Unsigned8| Read, | Power supply status of device |
| Status | | alarm | 0-power supply directly |
| | | | 1-power supplied by battery |
| | | | than 75% |
| | | | 2-power supplied by battery |
| | | | between 25% to 75% |
| | | | 3-power supplied by battery |
| | | | than 25% |
|-------------------------------------------------------------------|
| Device |Unsigned32| read | Device memory, in Bytes |
|Memory Total| | | |
|-------------------------------------------------------------------|
| Device |Unsigned32| read | Have used device memory, |
| Memory Used| | in Bytes |
|-------------------------------------------------------------------|
| Objects |Unsigned16| read | The number of object that is |
| Count | | | supported by device |
|-------------------------------------------------------------------|
| Object | Array | read | Object list that is supported |
| List | | | by device |
+-------------------------------------------------------------------+
DMO should send alarm in order to reporting the change of device
power status. Table 2 describes the alarm which is provided by DMO.
Table 2 DMO alarm
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+-------------------------------------------------------------------+
| Alarm name | Alarm | Data type | Description |
| | scale | | |
|-------------------------------------------------------------------|
|Device Power| Device | Unsigned8 | The value of Power Supply |
| Status | | | Status in table 1 |
+-------------------------------------------------------------------+
3.3.2. Alarm object
Alarm object may be used to report or deal with singularity events.
It mainly contains alert reporting management object and alert
receiving object.
3.3.2.1. Alert reporting management object
Alert reporting management object (ARMO) may be used to manage all
alert, every device should have an alert reporting management object,
all singularity events use alert reporting management object to
report. Table 3 describes the alert reporting management object
attribute. About the supported methods, see 4.4.1.
Table 3 ARMO attribute
+-------------------------------------------------------------------+
| Attribute |Data type|Supported| Description |
| name | | methods | |
|-------------------------------------------------------------------|
| ARMO | string | - | Object name |
|-------------------------------------------------------------------|
|Alert Master| JID or | read, | Device that receives |
| Device | IP | write | device scale alarm |
|-------------------------------------------------------------------|
|Alert Disable| string | read, | Disable or enable device scale |
| Device | | write | alarm, either enable or disable |
|-------------------------------------------------------------------|
|Alert Master | JID or | read, | Device that receives |
| Process | IP | write | process scale alarm |
|-------------------------------------------------------------------|
|Alert Disable| string | read, | Disable or enable process scale |
| Process | | write | alarm, either enable or disable |
+-------------------------------------------------------------------+
3.3.2.2. Alert receiving object
An alert receiving object (ARO) may receive one or more alert which
come from alert report source. Table 4 describes the alert receiving
object attribute. About the supported methods, see 4.4.1.
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Table 4 ARO attribute
+-------------------------------------------------------------------+
| Attribute |Data type|Supported| Description |
| name | | methods | |
|-------------------------------------------------------------------|
| ARO | string | - | Object name |
|-------------------------------------------------------------------|
| | | | Alarm scale that is supported by |
| Categories | string | read | this object , either device or |
| | | | process |
|-------------------------------------------------------------------|
| | | | The data of errors alarm, which |
| Errors |Unsigned16| read | is not belongs to the alarm scale|
| | | | that is supported by this object |
+-------------------------------------------------------------------+
3.3.3. User object
User object is defined by practice applications. This document takes
industries process control object for example to explaining how to
define the user object.
3.3.3.1. Process industries control object
Industries process control object collects industries process data by
sensor, such as temperature, pressure, flow and so on, each of which
is process data in site, and deal with these data. The industries
process control object which is defined in this document contains
analog input object and analog output object.
The functions of industries process control object are described in
follow.
Range conversion(scaling)
Range conversion which is convert the site data from one unit range
into another unit range is a linear conversion, which is help to
measuring and calculating in next. As convert the signal data from
4~20mA into 0~10Kpa. Range conversion may convert the united data
into disunited data, such as percentage and so on. and vice versa.
Linearization
Because of the characteristic of many sensors is nonlinear, even it
is irregular, therefore, it is necessary to linear in dealing with
the site data.
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Compensation
Because of sensor may be affected by environment, which may cause the
measure values become linear offset, so it is necessary to compensate
the offset.
Filtering
Because of sensor may be interfaced by environment and make the
measure values occur relatively large skip, so it is necessary to
filter the measure data to eliminate the bad effects which is leaded
by skip signal.
Dump
Dump is copy the data to a temporary storage area, in order to
resending when data is lost.
Engineering unit conversion
Engineering unit conversion converts the engineering unit of input
signal into engineering unit which can be identified by I/O subsystem.
Measuring time stamp
When the data that is collected by module is input, it is necessary
to record the current system time, in order to determining the time
of sending data between the user application object.
3.3.3.2. Analog input object
Analog input object (AIO) is used to sample the industries process,
and convert the physical signal into data with physical dimension.
Table 5 describes the object attribute, About the supported methods,
see 4.4.1.
Table 5 AIO attribute
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+-------------------------------------------------------------------+
| Attribute |Data type| Supported | Description |
| name | | methods | |
|-------------------------------------------------------------------|
| AIO | string | - | Object name |
|-------------------------------------------------------------------|
| Process | Float | read | Process variables |
| Value | | | |
|-------------------------------------------------------------------|
| | | read, |Measure values that is presented|
| Out Value | Float | publish, | by engineering unit |
| | | alarm | |
|-------------------------------------------------------------------|
| | | |It could start/stop the measure |
| Action | string | read, |process of AIO by setting the |
| | | write |attribute of Action, the value |
| | | |may be stop or start |
|-------------------------------------------------------------------|
| Sample |Unsigned32| read, |Sample period, the unit may be |
| Period | | write | s, m, h |
|-------------------------------------------------------------------|
| High Limit | Float | read, | The high value of AIO |
| | | write | |
|-------------------------------------------------------------------|
| Low Limit | Float | read, | The low value of AIO |
| | | write | |
|-------------------------------------------------------------------|
| Alarm | string | read |Alarm status, only three values |
| | | |could be selected: normal, high |
| | | | alarm, low alarm |
+-------------------------------------------------------------------+
Table 6 AIO alarm
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+-------------------------------------------------------------------+
| Alarm name| Alarm | Data | Description |
| | scale | type | |
|-------------------------------------------------------------------|
| High Alarm|Process| Float| When object detected the attribute of |
| | | | supporting alarm methods exceed the |
| | | | highest value, reporting it to ARMO, |
| | | |and the attribute is the current value. |
|-------------------------------------------------------------------|
| | | |When object detected the attribute of |
| Low Alarm |process| Float|supporting alarm methods less than the |
| | | |highest value, reporting it to ARMO, |
| | | |and the attribute is the current value. |
+-------------------------------------------------------------------+
3.3.3.3. Analog output object
Analog output object (AOO) is used to convert the output value into
value which is needed by hardware channel. Table 7 describes the
attribute of object, About the supported methods, see 4.4.1.
Table 7 AOO object
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+-------------------------------------------------------------------+
| Attribute |Data type| Supported | Description |
| name | | methods | |
|-------------------------------------------------------------------|
| AOO | string | - | Object name |
|-------------------------------------------------------------------|
| Out Value | Float |read, write,|Output value calculated from |
| | | publish, | the input value |
| | | reporte | |
|-------------------------------------------------------------------|
| Read Back | Float | read | Feedback data obtained from |
| Value | | | the actuator |
|-------------------------------------------------------------------|
| | | read, | Input data or manually input |
| Input Value| Float | write | data from other user |
| | | | application object |
|-------------------------------------------------------------------|
| | | read, | Set AOO start/stop output data |
| Action | string | write | to actuator, the value may be |
| | | | stop or start |
|-------------------------------------------------------------------|
| Output |Unsigned32| read, |Output period, the unit may be |
| Period | | write |s, m, h |
|-------------------------------------------------------------------|
| High Limit | Float | read, | The highest value of alarm |
| | | write | |
|-------------------------------------------------------------------|
| Low Limit | Float | read, | The lowest value of alarm |
| | | write | |
|-------------------------------------------------------------------|
| | | |Alarm status, only three values |
| Alarm | string | read |could be selected: normal, high |
| | | |alarm, low alarm |
+-------------------------------------------------------------------+
AOO alert is the same as AIO alert.
3.3.3.4. System monitor object
System monitor object is used to monitor system. Table 8 describes
the attribute of object.
Table 8 System monitor object
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+-------------------------------------------------------------------+
| Attribute |Data type | Supported | Description |
| name | | methods | |
|-------------------------------------------------------------------|
| SMO | string | - | Object name |
|-------------------------------------------------------------------|
| Device |Unsigned32| read | The number of device in |
| count | | | monitoring |
|-------------------------------------------------------------------|
| Device | String | read | The list of device in |
| List | array | | monitoring |
+-------------------------------------------------------------------+
3.4. Methods
Methods represent specific interface (function) of object, which is
used to access the data in object. This document divided the methods
into two types: public methods and private methods. The public
methods can be used in all objects, but the private methods only can
be used in one or a few object that own it, if the methods which are
defined to be public methods or private methods can realize the same
function, then it is unnecessary to redefine it.
3.4.1. Public methods
Table 9 describes the public methods which are defined in this
document.
Table 9 public methods
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+-------------------------------------------------------------------+
| Methods | Description | Communication mode |
| name | | |
|-------------------------------------------------------------------|
| read | Read the attribute values from | Client/Server |
| read | one object | |
|-------------------------------------------------------------------|
| write |Write to the attribute of one object| Client/Server |
|-------------------------------------------------------------------|
| execute |Implementation the private methods | Client/Server |
| | of one object | |
|-------------------------------------------------------------------|
| publish |Publish one or more attribute data | Publish/Subscribe |
|-------------------------------------------------------------------|
| report |Reporting alarm data | Source/Sink |
+-------------------------------------------------------------------+
3.4.2. Private methods
This protocol may add private methods of object to the document in
future.
3.4.3. Client/Server communication mode
Client/Server communication mode supports non-period communication
that is one-to-one. In this communication mode, both the any
communication point could play the role of client or server. Client
may send request to server, while the server must send response to
client. It is similar to the communication mode that is request-
response mode. Figure 2 represents the client/serve communication
mode.
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+-------------------------------------------+
| usr usr |
| +-----+ +-----+ |
| | | | | |
| +-----+ +-----+ |
| | client/server | |
| | request | |
| |----------------------------->| |
| | | |
| | client/server | |
| | response | |
| |<-----------------------------| |
| | | |
| +-----+ +-----+ |
| | | | | |
| +-----+ +-----+ |
+-------------------------------------------+
Figure 2 Client/Serve communication mode
3.4.4. Publish/Subscribe communication mode
Publish/Subscribe communication mode supports pre-configured and
periodic communication, which is no ACK or response. Configuration is
either configured by configure tool or configured by human. Figure 3
describes the publish/Subscribe communication mode.
+-------------------------------------------+
| usr usr |
| +-----+ +-----+ |
| | | | | |
| +-----+ +-----+ |
| | publish/subscribe | |
| | request | |
| |----------------------------->| |
| | | |
| | publish/subscribe | |
| | request | |
| |----------------------------->| |
| | | |
| +-----+ +-----+ |
| | | | | |
| +-----+ +-----+ |
+-------------------------------------------+
Figure 3 publish/Subscribe communication mode
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3.4.5. Source/Sink communication mode
Source/Sink communication mode is similar with the "push"
communication mode, which is used to alarm. Figure 4 describes the
source/Sink communication mode.
+-------------------------------------------+
| usr usr |
| +-----+ +-----+ |
| | | | | |
| +-----+ +-----+ |
| | publish/subscribe | |
| | request | |
| |----------------------------->| |
| | | |
| +-----+ +-----+ |
| | | | | |
| +-----+ +-----+ |
+-------------------------------------------+
Figure 4 source/Sink communication mode.
4. Protocol
4.1. Syntax
One object in an application may communicate with another object in
another application. Information and operation in one object can be
realized by the element of <object/>, the name space of which is
'http://jabber.org/protocol/wsn-object'. The element of <object/>
which is limited in 'http://jabber.org/protocol/wsn-object' should be
considered as the one level sub-element of <message/>stanza or <iq/>.
The element of <object/>must contain the attribute of 'from' and 'to',
in order to representing source object and destination object. The
basic syntax is as follows.
The syntax of sending request
<object xmlns='http://jabber.org/protocol/wsn-object'from='source-obj' to='target-obj'>
<command var='public-method-name'>
<method var='private-method-name'>
<inargument var='argument_name'>input_argument_value</inargument >
</method>
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<attribute var='attribute_name'>attribute_value</attribute>
</command>
</object>
The syntax of sending response
<object xmlns='http://jabber.org/protocol/wsn-object'from='source-obj' to='target-obj'>
<response>
<method var='private-method-name'>
<outargument var='argument_name'>output_argument_value</outargument>
<method/>
<attribute var='attribute_name'>attribute_value</attribute>
<attribute var='attribute_name'>
<item var='item_name'>item_value</item>
</attribute>
<response>
</object>
Or
<object xmlns='http://jabber.org/protocol/wsn-object'from='source-obj' to='target-obj'>
<error>
text
</error>
</object>
4.2. Element
Except the element of <object/>, this protocol also defined other
elements.
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<command/>
The element of <command/> represents the operation of source object,
which must have the attribute of 'var', the attribute of 'var'
indicate public methods that need to be executed. Take the 'var'
= 'read' for example, which represent the source object need be
operated on read.
<method/>
If the element of <method/> value is "execute", then the element of
<command/> must contain an element of <method/>, and the element of
<method/> must contain the attribute of 'var'. It is used to indicate
private methods which need be executed. If the private methods that
need be executed defined input parameter, then the element of
<method/> should contain sub-element which is named by input
parameter name.
<attribute/>
The element of <attribute/> represent object attribute that need to
be read or wrote, which must contain an attribute of 'var' to
indicting detail object attribute.
<item/>
When one attribution data type is array or structure, then using the
element of <item/>, which must contain an attribute of 'var' to
indicting detail one in attribute. Such as the elements of object
list in DMO.
<detector/>
The element of <detector/> represent detected object of alarm events,
if the attribute value of 'var' which belongs to element of <command>
is "report", then the element of <command> must contain an element of
<detector/>, the element of <detector/> must have an attribute of
'var', which is used to represent detected object of alarm events.
<alert/>
The element of <alert/> represent alarm that is sent, if the
attribute value of 'var' which belongs to element of <command> is
"report", then the element of <command> must contain at least one
element of <alert/>, the element of <alert/> must have an attribute
of 'type' and 'var', which are used to represent scale of alarm
events and the detail alarm events.
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<response/>
If XML stanza is response message that is succeed request, then the
element of <object/> should contain the element of <response/>, the
element of <response/> shall contain result of executing request,
which including output parameter of executing private methods, read
attribute values and so on. If the operation of request is succeed,
but no content is return, then set the <response/> to null.
<error/>
If request operation is failed, then the element of <object/> in
response message should contain the element of <error/> to describe
error. The <error/> is also null, which is defined by application
process.
4.3. Communicated processing examples
Object operates attribute and private methods in object by public
methods. The communication modes of public methods are different from
one to one. The methods of reading, writing or executing are in
support of the Client/Server communication mode, which is similar to
the communication mode of Request/Response, therefore, when it is
necessary to use these three methods, it should use <iq/> stanza to
transmit, which is defined in the XMPP core protocol, it uses
<message/> stanza to transmit when it uses the methods of alarm or
alarm ACK, the methods of publisher uses the communication mode of
Publish/Subscribe, because of the publisher in this document
published not only presence status, so it should not use the
<presence/> stanza. The methods of publisher also use the <message/>
stanza to transmit.
Assuming the XMPP application of host contains SMO or ARO, and the
XMPP application of sensor which is included in industrial wireless
sensor networks contains DMO, AIO and ARMO, The following examples
describe the communication among them.
Example1. Reading single attribute data: system monitoring object of
host read sample values of sensor AIO.
Host sends the read request
<iq type='get'from='monitor@server' to='node@server' id='get_1'>
<object from='SMO' to='AIO'>
<command var='read'>
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<attribute var='ProcessValue'/>
</command>
</object>
</iq>
Sensor response the read request (success)
<iq type='result from='node@server' to='monitor@server' id='get_1'>
<object from='AIO' to='SMO'>
<response>
<attribute var='ProcessValue'>
2.56
</attribute>
</response>
</object>
</iq>
Sensor responding the read request (failed)
<iq type='result' from='node@server' to='monitor@server' id='get_1>
<object from='AIO' to='SMO'>
<error>
Read failed
</error>
</object>
</iq>
Example2. Read multiple attribute data: system monitoring object of
host reads sample values of sensor AIO and sample period.
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Host sends the read request
<iq type='get' from='monitor@server' to='node@server' id='get_1'>
<object from='SMO' to='AIO'>
<command var='read'>
<attribute var='ProcessValue'/>
<attribute var='SamplePeriod'/>
</command>
</object>
</iq>
Sensor response the read request (success)
<iq type='result' from='node@server' to='monitor@server' id='get_1'>
<object from='AIO' to='SMO'>
<response>
<attribute var='ProcessValue'>2.56<attribute/>
<attribute var='SamplePeriod'>2m<attribute/>
</response>
</object>
</iq>
Sensor response the read request (failed)
<iq type='result'from='node@server' to='monitor@server' id='get_1'>
<object from='AIO' to='SMO'>
<error>
Read failed
</error>
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</object>
<iq/>
When reading the multiple attribute data, if reading a part of
attribute data is success, but writing a part of attribute data is
failed, then deal with it by failed, and return the read operate with
failed.
Example3: system monitoring object of host read the Object List
attribute of sensor DMO.
Host sends the read request
<iq type='get' from='monitor@server' to='node@server' id='get_1'>
<object from='SMO' to='DMO'>
<command var='read'>
<attribute var='ObjectList'/>
</command>
</object>
</iq>
Sensor response the read request (success)
<iq type='result' from='node@server' to='monitor@server' id='get_1'>
<object from='DMO' to='SMO'>
<response>
<attribute var='ObjectList'>
<item var='DMO'/>
<item var='ARMO'/>
<item var='AIO'/>
</attribute>
</response>
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</object>
</iq>
Sensor response the read request (failed)
<iq type='result' from='node@server' to='monitor@server'id='get_1'>
<object from='AIO'to='SMO'>
<error>
Read failed
</error>
</object>
</iq>
Example4: Set single attribute data: system monitoring object of host
write sample period of sensor AIO.
Host sends write request
<iq type='set' from='monitor@server' to='node@server' id='get_1'>
<object from='SMO' to='AIO'>
<command var='write'>
<attribute var='SamplePeriod'>
3h
</attribute>
</command>
</object>
<iq/>
Sensor response write request (success)
<iq type='result' from='node@server' to='monitor@server' id='get_1'>
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<object from='AIO' to='SMO'>
<response/>
</object>
</iq>
Sensor response write request (failed)
<iq type='result'from='node@server' to='monitor@server' id='get_1'>
<object from='AIO' to='SMO'>
<error/>
</object>
</iq>
Example5: Set multiple attribute data: system monitoring object of
host write sample period and the highest value of alarm of sensor AIO.
Host sends write request
<iq type='set' from='monitor@server' <object from='SMO' to='AIO'>
<command var='write'>
<attribute var='SamplePeriod'>3h</attribute>
<attribute var='HighLimit'>20</attribute>
</command>
</object>
Sensor response write request (success)
<iq type='result' from='node@server' to='monitor@server' id='get_1'>
<object from='AIO' to='SMO'>
<response/>
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</object>
</iq>
Sensor response write request (failed)
<iq type='result' from='node@server' to='monitor@server'id='get_1'>
<object from='AIO' to='SMO'>
<error/>
</object>
</iq>
When writing multiple attribute data, if writing a part of attribute
data is success, but writing a part of attribute data is failed, then
deal with it by failed, and return the write operate with failed.
Example6: According to the pre-configured, sensor AIO sending measure
values to the system monitoring object of host on time.
<message from='node@server' to='monitor@server'>
<object from='AIO' to='SMO'>
<command var='publish'>
<attribute var='OutValue'>
2.56
</attribute>
</command>
</object>
</message>
Example7: When the measure values of sensor AIO exceeded the highest
value of alarm, sensor AIO shall report that to sensor ARMO, and set
the attribute of 'alarm' to 'high alarm'. Assuming the attribute
values of 'Alert Master Process' which are included in sensor ARMO
are initialized to 'monitor@server', and the attribute values of
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'Alert Disable Process' are initialized to 'enable', then sensor ARMO
send alert to host ARO.
<message from='node@server' to='monitor@server'>
<object from='ARMO' to='ARO'>
<command var='report'>
<detector var='AIO'/>
<alert var='HighAlarm' type='process'>
26
</alert>
</command>
</object>
</message>
5. Security Considerations
This document has no requirement for a change to the security models
within associated protocols.
6. IANA Considerations
This document defined the protocol name space, which is the
'http://jabber.org/protocol/wsn-object'.it should add the protocol
name space to 'http://xmpp.org/registrar/namespaces.html' according
to the definition of XMPP Registrar Function.
7. References
7.1. Normative References
[XMPP-CORE] Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Core", RFC 6120, March 2011
[KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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7.2. Informative References
[IMP-REQS] Day, M., Aggarwal, S., and J. Vincent, "Instant
Messaging/Presence Protocol Requirements", RFC 2779,
February 2000.
Appendix A. XML Schema
<?xml version='1.0'encoding='UTF-8'?>
<xs:schema
xmlns:xs='http://www.w3.org/2001/XMLSchema'
targetNamespace='http://jabber.org/protocol/wsn-object'
xmlns='http://jabber.org/protocol/wsn-object'
elementFormDefault='qualified'>
<xs:element name='object'>
<xs:complexType>
<xs:choice minOccurs='1'maxOccurs='1'/>
<xs:element name='command'minOccurs='0'/>
<xs:element name='response'minOccurs='0'/>
<xs:element name='error'minOccurs='0'/>
</xs:choice>
<xs:attribute name='from' type='xs:string' use='required'/>'
<xs:attribute name='to' type='xs:string' use='required'/>
</xs:complexType>
</xs:element>
<xs:element name='command'>
<xs:complexType>
<xs:choice minOccurs='1' maxOccurs='unbounded >
<xs:element name='attribute' minOccurs='0' maxOccurs='1'/>
<xs:element name='method' minOccurs='0' maxOccurs='1'/>
<xs:element name='alert' minOccurs= '0' maxOccurs='1'/>
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</xs:choice>
<xs:attribute name='var' type='xs:string' use='required'/>
<xs:simpleType>
<xs: restriction base='xs:string'>
<xs:enumeration value='read'/>
<xs:enumeration value='write'/>
<xs:enumeration value='execute'/>
<xs:enumeration value='publish'/>
<xs:enumeration value='report'/>
</xs:restriction>
</xs:simpleType>
</xs:complexType>
</xs:element>
<xs:element name='response'>
<xs:complexType>
<xs:choice minOccurs='1'maxOccurs='unbounded >
<xs:element name='attribute' minOccurs='0'maxOccurs='unbounded/>
<xs:element name='method' minOccurs='0'/>
</xs:choice>
</xs:complexType>
</xs:element>
<xs:element name='error'>
<xs:complexType>
<xs:simpleContent>
<xs:extension base='xs:string'/>
</xs:simpleContent>
</xs:complexType>
</xs:element>
<xs:element name='attribute'>
<xs:attribute name='var' type='xs:string' use='required'/>
</xs:element>
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<xs:element name='method'>
<xs:complexType>
<xs:sequence>
<xs:element ref='inargment'/>
<xs:element ref='outargment'/>
</xs:sequence>
<xs:attribute name='var' type='xs:string' use='required'/>
</xs:complexType>
</xs:element>
<xs:element name='alert'>
<xs:attribute name='var' type='xs:string' use='required'/>
</xs:element>
</xs:schema>
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Authors' Addresses
Ping Wang
Chongqing University of Posts and Telecommunications
Administrative Building, Chongqing University of Posts and
Telecommunications
Chongqing, 400065
China
Phone: (86) -23- 6246- 1061
Email: wangping@cqupt.edu.cn
Heng Wang
Chongqing University of Posts and Telecommunications
Administrative Building, Chongqing University of Posts and
Telecommunications
Chongqing, 400065
China
Phone: (86) -23- 6248- 7845
Email: wangheng@cqupt.edu.cn
Chao Zhou
Cisco Systems (China)
Research and Development Co., Ltd.
8Floor, Xinsi Mansion
926 Yinshan Lu, Caohejing Hi-Tech Park,
Shanghai, 200233
China
Phone: (86) -21- 2407- 3419
Email: czhou@cisco.com
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