draft-ietf-core-senml-02.txt		draft-ietf-core-senml-03.txt
	Network Working Group C. Jennings		Network Working Group C. Jennings
	Internet-Draft Cisco		Internet-Draft Cisco
	Intended status: Standards Track Z. Shelby		Intended status: Standards Track Z. Shelby
	Expires: January 9, 2017 ARM		Expires: April 10, 2017 ARM
	J. Arkko		J. Arkko
	A. Keranen		A. Keranen
	Ericsson		Ericsson
	C. Bormann		C. Bormann
	Universitaet Bremen TZI		Universitaet Bremen TZI
	July 8, 2016		October 7, 2016
	Media Types for Sensor Markup Language (SenML)		Media Types for Sensor Markup Language (SenML)
	draft-ietf-core-senml-02		draft-ietf-core-senml-03
	Abstract		Abstract
	This specification defines media types for representing simple sensor		This specification defines media types for representing simple sensor
	measurements and device parameters in the Sensor Markup Language		measurements and device parameters in the Sensor Markup Language
	(SenML). Representations are defined in JavaScript Object Notation		(SenML). Representations are defined in JavaScript Object Notation
	(JSON), Concise Binary Object Representation (CBOR), eXtensible		(JSON), Concise Binary Object Representation (CBOR), eXtensible
	Markup Language (XML), and Efficient XML Interchange (EXI), which		Markup Language (XML), and Efficient XML Interchange (EXI), which
	share the common SenML data model. A simple sensor, such as a		share the common SenML data model. A simple sensor, such as a
	temperature sensor, could use this media type in protocols such as		temperature sensor, could use this media type in protocols such as
	skipping to change at page 1, line 44 ¶		skipping to change at page 1, line 44 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on January 9, 2017.		This Internet-Draft will expire on April 10, 2017.
	Copyright Notice		Copyright Notice
	Copyright (c) 2016 IETF Trust and the persons identified as the		Copyright (c) 2016 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 28 ¶		skipping to change at page 2, line 28 ¶
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Requirements and Design Goals . . . . . . . . . . . . . . . . 4		2. Requirements and Design Goals . . . . . . . . . . . . . . . . 4
	3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5		3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
	4. SenML Structure and Semantics . . . . . . . . . . . . . . . . 5		4. SenML Structure and Semantics . . . . . . . . . . . . . . . . 5
	4.1. Base attributes . . . . . . . . . . . . . . . . . . . . . 5		4.1. Base attributes . . . . . . . . . . . . . . . . . . . . . 5
	4.2. Regular attributes . . . . . . . . . . . . . . . . . . . 6		4.2. Regular attributes . . . . . . . . . . . . . . . . . . . 6
	4.3. Considerations . . . . . . . . . . . . . . . . . . . . . 6		4.3. Considerations . . . . . . . . . . . . . . . . . . . . . 7
	4.4. Associating Meta-data . . . . . . . . . . . . . . . . . . 8		4.4. Resolved Records . . . . . . . . . . . . . . . . . . . . 8
	5. JSON Representation (application/senml+json) . . . . . . . . 8		4.5. Associating Meta-data . . . . . . . . . . . . . . . . . . 8
	5.1. Examples . . . . . . . . . . . . . . . . . . . . . . . . 9		5. JSON Representation (application/senml+json) . . . . . . . . 9
	5.1.1. Single Datapoint . . . . . . . . . . . . . . . . . . 9		5.1. Examples . . . . . . . . . . . . . . . . . . . . . . . . 10
	5.1.2. Multiple Datapoints . . . . . . . . . . . . . . . . . 9		5.1.1. Single Datapoint . . . . . . . . . . . . . . . . . . 10
			5.1.2. Multiple Datapoints . . . . . . . . . . . . . . . . . 10
	5.1.3. Multiple Measurements . . . . . . . . . . . . . . . . 11		5.1.3. Multiple Measurements . . . . . . . . . . . . . . . . 11
	5.1.4. Collection of Resources . . . . . . . . . . . . . . . 12		5.1.4. Resolved Data . . . . . . . . . . . . . . . . . . . . 12
	6. CBOR Representation (application/senml+cbor) . . . . . . . . 12		5.1.5. Multiple Data Types . . . . . . . . . . . . . . . . . 12
	7. XML Representation (application/senml+xml) . . . . . . . . . 13		5.1.6. Collection of Resources . . . . . . . . . . . . . . . 13
	8. EXI Representation (application/senml-exi) . . . . . . . . . 15		6. CBOR Representation (application/senml+cbor) . . . . . . . . 13
	9. Usage Considerations . . . . . . . . . . . . . . . . . . . . 17		7. XML Representation (application/senml+xml) . . . . . . . . . 15
	10. CDDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18		8. EXI Representation (application/senml+exi) . . . . . . . . . 17
	11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20		9. Usage Considerations . . . . . . . . . . . . . . . . . . . . 20
	11.1. Units Registry . . . . . . . . . . . . . . . . . . . . . 20		10. CDDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
	11.2. SenML label registry . . . . . . . . . . . . . . . . . . 24		11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
	11.3. Media Type Registration . . . . . . . . . . . . . . . . 24		11.1. Units Registry . . . . . . . . . . . . . . . . . . . . . 23
	11.3.1. senml+json Media Type Registration . . . . . . . . . 24		11.2. SenML Label Registry . . . . . . . . . . . . . . . . . . 26
	11.3.2. senml+cbor Media Type Registration . . . . . . . . . 25		11.3. Media Type Registration . . . . . . . . . . . . . . . . 27
	11.3.3. senml+xml Media Type Registration . . . . . . . . . 26		11.3.1. senml+json Media Type Registration . . . . . . . . . 27
	11.3.4. senml-exi Media Type Registration . . . . . . . . . 27		11.3.2. senml+cbor Media Type Registration . . . . . . . . . 29
	11.4. XML Namespace Registration . . . . . . . . . . . . . . . 28		11.3.3. senml+xml Media Type Registration . . . . . . . . . 29
	11.5. CoAP Content-Format Registration . . . . . . . . . . . . 28		11.3.4. senml+exi Media Type Registration . . . . . . . . . 30
	12. Security Considerations . . . . . . . . . . . . . . . . . . . 28		11.4. XML Namespace Registration . . . . . . . . . . . . . . . 31
	13. Privacy Considerations . . . . . . . . . . . . . . . . . . . 28		11.5. CoAP Content-Format Registration . . . . . . . . . . . . 31
	14. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 29		12. Security Considerations . . . . . . . . . . . . . . . . . . . 32
	15. References . . . . . . . . . . . . . . . . . . . . . . . . . 29		13. Privacy Considerations . . . . . . . . . . . . . . . . . . . 32
	15.1. Normative References . . . . . . . . . . . . . . . . . . 29		14. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 32
	15.2. Informative References . . . . . . . . . . . . . . . . . 30		15. References . . . . . . . . . . . . . . . . . . . . . . . . . 32
	Appendix A. Links extension . . . . . . . . . . . . . . . . . . 31		15.1. Normative References . . . . . . . . . . . . . . . . . . 32
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31		15.2. Informative References . . . . . . . . . . . . . . . . . 34
			Appendix A. Links Extension . . . . . . . . . . . . . . . . . . 35
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 35
	1. Overview		1. Overview
	Connecting sensors to the Internet is not new, and there have been		Connecting sensors to the Internet is not new, and there have been
	many protocols designed to facilitate it. This specification defines		many protocols designed to facilitate it. This specification defines
	new media types for carrying simple sensor information in a protocol		new media types for carrying simple sensor information in a protocol
	such as HTTP or CoAP. This format was designed so that processors		such as HTTP or CoAP. This format was designed so that processors
	with very limited capabilities could easily encode a sensor		with very limited capabilities could easily encode a sensor
	measurement into the media type, while at the same time a server		measurement into the media type, while at the same time a server
	parsing the data could relatively efficiently collect a large number		parsing the data could relatively efficiently collect a large number
	skipping to change at page 3, line 47 ¶		skipping to change at page 4, line 5 ¶
	single array that contains a series of SenML Records which can each		single array that contains a series of SenML Records which can each
	contain attributes such as an unique identifier for the sensor, the		contain attributes such as an unique identifier for the sensor, the
	time the measurement was made, the unit the measurement is in, and		time the measurement was made, the unit the measurement is in, and
	the current value of the sensor. Serializations for this data model		the current value of the sensor. Serializations for this data model
	are defined for JSON [RFC7159], CBOR [RFC7049], XML, and Efficient		are defined for JSON [RFC7159], CBOR [RFC7049], XML, and Efficient
	XML Interchange (EXI) [W3C.REC-exi-20110310].		XML Interchange (EXI) [W3C.REC-exi-20110310].
	For example, the following shows a measurement from a temperature		For example, the following shows a measurement from a temperature
	gauge encoded in the JSON syntax.		gauge encoded in the JSON syntax.
	[{ "n": "urn:dev:ow:10e2073a01080063", "v":23.1, "u":"Cel" }]		[
			{"n":"urn:dev:ow:10e2073a01080063","u":"Cel","v":23.1}
			]
	In the example above, the array has a single SenML Record with a		In the example above, the array has a single SenML Record with a
	measurement for a sensor named "urn:dev:ow:10e2073a01080063" with a		measurement for a sensor named "urn:dev:ow:10e2073a01080063" with a
	current value of 23.1 degrees Celsius.		current value of 23.1 degrees Celsius.
	2. Requirements and Design Goals		2. Requirements and Design Goals
	The design goal is to be able to send simple sensor measurements in		The design goal is to be able to send simple sensor measurements in
	small packets on mesh networks from large numbers of constrained		small packets on mesh networks from large numbers of constrained
	devices. Keeping the total size of payload under 80 bytes makes this		devices. Keeping the total size of payload under 80 bytes makes this
	skipping to change at page 4, line 29 ¶		skipping to change at page 4, line 37 ¶
	where the sensor itself sends just a single data item at a time. The		where the sensor itself sends just a single data item at a time. The
	multiple measurements could be from multiple related sensors or from		multiple measurements could be from multiple related sensors or from
	the same sensor but at different times.		the same sensor but at different times.
	The basic design is an array with a series of measurements. The		The basic design is an array with a series of measurements. The
	following example shows two measurements made at different times.		following example shows two measurements made at different times.
	The value of a measurement is in the "v" tag, the time of a		The value of a measurement is in the "v" tag, the time of a
	measurement is in the "t" tag, the "n" tag has a unique sensor name,		measurement is in the "t" tag, the "n" tag has a unique sensor name,
	and the unit of the measurement is carried in the "u" tag.		and the unit of the measurement is carried in the "u" tag.
	[		[
	{ "n": "urn:dev:ow:10e2073a01080063",		{"n":"urn:dev:ow:10e2073a01080063","u":"Cel","t":1.276020076e+09,"v":23.5},
	"t": 1276020076, "v":23.5, "u":"Cel" },		{"n":"urn:dev:ow:10e2073a01080063","u":"Cel","t":1.276020091e+09,"v":23.6}
	{ "n": "urn:dev:ow:10e2073a01080063",		]
	"t": 1276020091, "v":23.6, "u":"Cel" }
	]
	To keep the messages small, it does not make sense to repeat the "n"		To keep the messages small, it does not make sense to repeat the "n"
	tag in each SenML Record so there is a concept of a Base Name which		tag in each SenML Record so there is a concept of a Base Name which
	is simply a string that is prepended to the Name field of all		is simply a string that is prepended to the Name field of all
	elements in that record and any records that follow it. So a more		elements in that record and any records that follow it. So a more
	compact form of the example above is the following.		compact form of the example above is the following.
	[		[
	{ "bn": "urn:dev:ow:10e2073a01080063",		{"bn":"urn:dev:ow:10e2073a01080063","u":"Cel","t":1.276020076e+09,"v":23.5},
	"t": 1276020076, "v":23.5, "u":"Cel" },		{"u":"Cel","t":1.276020091e+09,"v":23.6}
	{ "t": 1276020091, "v":23.6, "u":"Cel" }		]
	]
	In the above example the Base Name is in the "bn" tag and the "n"		In the above example the Base Name is in the "bn" tag and the "n"
	tags in each Record are the empty string so they are omitted.		tags in each Record are the empty string so they are omitted.
	Some devices have accurate time while others do not so SenML supports		Some devices have accurate time while others do not so SenML supports
	absolute and relative times. Time is represented in floating point		absolute and relative times. Time is represented in floating point
	as seconds and values greater than zero represent an absolute time		as seconds and values greater than zero represent an absolute time
	relative to the Unix epoch while values of 0 or less represent a		relative to the Unix epoch while values of 0 or less represent a
	relative time in the past from the current time. A simple sensor		relative time in the past from the current time. A simple sensor
	with no absolute wall clock time might take a measurement every		with no absolute wall clock time might take a measurement every
	second and batch up 60 of them then send it to a server. It would		second and batch up 60 of them then send it to a server. It would
	skipping to change at page 6, line 8 ¶		skipping to change at page 6, line 13 ¶
	Base Time: A base time that is added to the time found in an entry.		Base Time: A base time that is added to the time found in an entry.
	Base Unit: A base unit that is assumed for all entries, unless		Base Unit: A base unit that is assumed for all entries, unless
	otherwise indicated. If a record does not contain a Unit value,		otherwise indicated. If a record does not contain a Unit value,
	then the Base Unit is used. Otherwise the value found in the Unit		then the Base Unit is used. Otherwise the value found in the Unit
	(if any) is used.		(if any) is used.
	Base Value: A base value is added to the value found in an entry,		Base Value: A base value is added to the value found in an entry,
	similar to Base Time.		similar to Base Time.
			Base Sum: A base sum is added to the sum found in an entry, similar
			to Base Time.
	Version: Version number of media type format. This attribute is an		Version: Version number of media type format. This attribute is an
	optional positive integer and defaults to 5 if not present. [RFC		optional positive integer and defaults to 5 if not present. [RFC
	Editor: change the default value to 10 when this specification is		Editor: change the default value to 10 when this specification is
	published as an RFC and remove this note]		published as an RFC and remove this note]
	4.2. Regular attributes		4.2. Regular attributes
	Name: Name of the sensor or parameter. When appended to the Base		Name: Name of the sensor or parameter. When appended to the Base
	Name attribute, this must result in a globally unique identifier		Name attribute, this must result in a globally unique identifier
	for the resource. The name is optional, if the Base Name is		for the resource. The name is optional, if the Base Name is
	present. If the name is missing, Base Name must uniquely identify		present. If the name is missing, Base Name must uniquely identify
	the resource. This can be used to represent a large array of		the resource. This can be used to represent a large array of
	measurements from the same sensor without having to repeat its		measurements from the same sensor without having to repeat its
	identifier on every measurement.		identifier on every measurement.
	Unit: Units for a measurement value. Optional. If the Record has		Unit: Units for a measurement value. Optional. If the Record has
	no Unit, the Base Unit is used as the Unit. Having no Unit and no		no Unit, the Base Unit is used as the Unit. Having no Unit and no
	Base Unit is allowed.		Base Unit is allowed.
	Value Value of the entry. Optional if a Sum value is present,		Value Value of the entry. Optional if a Sum value is present,
	otherwise required. Values are represented using three basic data		otherwise required. Values are represented using basic data
	types, Floating point numbers ("v" field for "Value"), Booleans		types. This specification defines floating point numbers ("v"
	("vb" for "Boolean Value"), Strings ("vs" for "String Value") and		field for "Value"), booleans ("vb" for "Boolean Value"), strings
	Binary Data ("vd" for "Data Value") . Exactly one of these four		("vs" for "String Value") and binary data ("vd" for "Data Value").
	fields MUST appear unless there is Sum field in which case it is		Exactly one value field MUST appear unless there is Sum field in
	allowed to have no Value field or to have "v" field.		which case it is allowed to have no Value field.
	Sum: Integrated sum of the values over time. Optional. This		Sum: Integrated sum of the values over time. Optional. This
	attribute is in the units specified in the Unit value multiplied		attribute is in the units specified in the Unit value multiplied
	by seconds.		by seconds.
	Time: Time when value was recorded. Optional.		Time: Time when value was recorded. Optional.
	Update Time: An optional time in seconds that represents the maximum		Update Time: An optional time in seconds that represents the maximum
	time before this sensor will provide an updated reading for a		time before this sensor will provide an updated reading for a
	measurement. This can be used to detect the failure of sensors or		measurement. This can be used to detect the failure of sensors or
	skipping to change at page 7, line 50 ¶		skipping to change at page 8, line 8 ¶
	If either the Base Time or Time value is missing, the missing		If either the Base Time or Time value is missing, the missing
	attribute is considered to have a value of zero. The Base Time and		attribute is considered to have a value of zero. The Base Time and
	Time values are added together to get the time of measurement. A		Time values are added together to get the time of measurement. A
	time of zero indicates that the sensor does not know the absolute		time of zero indicates that the sensor does not know the absolute
	time and the measurement was made roughly "now". A negative value is		time and the measurement was made roughly "now". A negative value is
	used to indicate seconds in the past from roughly "now". A positive		used to indicate seconds in the past from roughly "now". A positive
	value is used to indicate the number of seconds, excluding leap		value is used to indicate the number of seconds, excluding leap
	seconds, since the start of the year 1970 in UTC.		seconds, since the start of the year 1970 in UTC.
			If only one of the Base Sum or Sum value is present, the missing
			attribute is considered to have a value of zero. The Base Sum and
			Sum values are added together to get the sum of measurement. If
			neither the Base Sum or Sum are present, then the measurement does
			not have a sum value.
	Representing the statistical characteristics of measurements, such as		Representing the statistical characteristics of measurements, such as
	accuracy, can be very complex. Future specification may add new		accuracy, can be very complex. Future specification may add new
	attributes to provide better information about the statistical		attributes to provide better information about the statistical
	properties of the measurement.		properties of the measurement.
	A SenML object is referred to as "expanded" if it does not contain		4.4. Resolved Records
	any base values and has no relative times.
	4.4. Associating Meta-data		Sometimes it is useful to be able to refer to a defined normalized
			format for SenML records. This normalized format tends to get used
			for big data applications and intermediate forms when converting to
			other formats.
			A SenML Record is referred to as "resolved" if it does not contain
			any base values and has no relative times, but the base values of the
			SenML Pack (if any) are applied to the Record. That is, name and
			base name are concatenated, base time is added to the time of the
			Record, if the Record did not contain Unit the Base Unit is applied
			to the record, etc. In addition the records need to be in
			chronological order. An example of this is show in Section 5.1.4.
			Future specification that defines new base attributes need to specify
			how the attribute is resolved.
			4.5. Associating Meta-data
	SenML is designed to carry the minimum dynamic information about		SenML is designed to carry the minimum dynamic information about
	measurements, and for efficiency reasons does not carry significant		measurements, and for efficiency reasons does not carry significant
	static meta-data about the device, object or sensors. Instead, it is		static meta-data about the device, object or sensors. Instead, it is
	assumed that this meta-data is carried out of band. For web		assumed that this meta-data is carried out of band. For web
	resources using SenML Packs, this meta-data can be made available		resources using SenML Packs, this meta-data can be made available
	using the CoRE Link Format [RFC6690]. The most obvious use of this		using the CoRE Link Format [RFC6690]. The most obvious use of this
	link format is to describe that a resource is available in a SenML		link format is to describe that a resource is available in a SenML
	format in the first place. The relevant media type indicator is		format in the first place. The relevant media type indicator is
	included in the Content-Type (ct=) attribute.		included in the Content-Type (ct=) attribute.
	skipping to change at page 8, line 34 ¶		skipping to change at page 9, line 17 ¶
	The SenML labels (JSON object member names) shown in Table 1 are used		The SenML labels (JSON object member names) shown in Table 1 are used
	in JSON SenML Record attributes.		in JSON SenML Record attributes.
	+---------------+-------+---------+		+---------------+-------+---------+
	| Name | label | Type |		| Name | label | Type |
	+---------------+-------+---------+		+---------------+-------+---------+
	| Base Name | bn | String |		| Base Name | bn | String |
	| Base Time | bt | Number |		| Base Time | bt | Number |
	| Base Unit | bu | String |		| Base Unit | bu | String |
	| Base Value | bv | Number |		| Base Value | bv | Number |
			| Base Sum | bs | Number |
	| Version | bver | Number |		| Version | bver | Number |
	| Name | n | String |		| Name | n | String |
	| Unit | u | String |		| Unit | u | String |
	| Value | v | Number |		| Value | v | Number |
	| String Value | vs | String |		| String Value | vs | String |
	| Boolean Value | vb | Boolean |		| Boolean Value | vb | Boolean |
	| Data Value | vd | String |		| Data Value | vd | String |
	| Value Sum | s | Number |		| Value Sum | s | Number |
	| Time | t | Number |		| Time | t | Number |
	| Update Time | ut | Number |		| Update Time | ut | Number |
			| Link | l | String |
	+---------------+-------+---------+		+---------------+-------+---------+
	Table 1: JSON SenML Labels		Table 1: JSON SenML Labels
	The root content consists of an array with one JSON object for each		The root content consists of an array with one JSON object for each
	SenML Record. All the fields in the above table MAY occur in the		SenML Record. All the fields in the above table MAY occur in the
	records with the type specified in the table.		records with the type specified in the table.
	Only the UTF-8 form of JSON is allowed. Characters in the String		Only the UTF-8 form of JSON is allowed. Characters in the String
	Value are encoded using the escape sequences defined in [RFC7159].		Value are encoded using the escape sequences defined in [RFC7159].
	Characters in the Data Value are base64 encoded with URL safe		Octets in the Data Value are base64 encoded with URL safe alphabet as
	alphabet as defined in Section 5 of [RFC4648].		defined in Section 5 of [RFC4648].
	Systems receiving measurements MUST be able to process the range of		Systems receiving measurements MUST be able to process the range of
	floating point numbers that are representable as an IEEE double-		floating point numbers that are representable as an IEEE double
	precision floating-point numbers [IEEE.754.1985]. The number of		precision floating point numbers [IEEE.754.1985]. The number of
	significant digits in any measurement is not relevant, so a reading		significant digits in any measurement is not relevant, so a reading
	of 1.1 has exactly the same semantic meaning as 1.10. If the value		of 1.1 has exactly the same semantic meaning as 1.10. If the value
	has an exponent, the "e" MUST be in lower case. The mantissa SHOULD		has an exponent, the "e" MUST be in lower case. The mantissa SHOULD
	be less than 19 characters long and the exponent SHOULD be less than		be less than 19 characters long and the exponent SHOULD be less than
	5 characters long. This allows time values to have better than micro		5 characters long. This allows time values to have better than micro
	second precision over the next 100 years.		second precision over the next 100 years.
	5.1. Examples		5.1. Examples
	TODO - Add example with string, data, boolean, and base value
	5.1.1. Single Datapoint		5.1.1. Single Datapoint
	The following shows a temperature reading taken approximately "now"		The following shows a temperature reading taken approximately "now"
	by a 1-wire sensor device that was assigned the unique 1-wire address		by a 1-wire sensor device that was assigned the unique 1-wire address
	of 10e2073a01080063:		of 10e2073a01080063:
	[{ "n": "urn:dev:ow:10e2073a01080063", "v":23.1, "u":"Cel" }]		[
			{"n":"urn:dev:ow:10e2073a01080063","u":"Cel","v":23.1}
			]
	5.1.2. Multiple Datapoints		5.1.2. Multiple Datapoints
	The following example shows voltage and current now, i.e., at an		The following example shows voltage and current now, i.e., at an
	unspecified time.		unspecified time.
	[ {"bn": "urn:dev:ow:10e2073a01080063",		[
	"n": "voltage", "t": 0, "u": "V", "v": 120.1 },		{"bn":"urn:dev:ow:10e2073a01080063","n":"voltage","u":"V","v":120.1},
	{"n": "current", "t": 0, "u": "A", "v": 1.2 }		{"n":"current","u":"A","v":1.2}
	]		]
	The next example is similar to the above one, but shows current at		The next example is similar to the above one, but shows current at
	Tue Jun 8 18:01:16.001 UTC 2010 and at each second for the previous 5		Tue Jun 8 18:01:16.001 UTC 2010 and at each second for the previous 5
	seconds.		seconds.
	[{"bn": "urn:dev:ow:10e2073a01080063/",		[
	"bt": 1276020076.001,		{"bn":"urn:dev:ow:10e2073a01080063/","bt":1.276020076001e+09,"bu":"A","bver":5,
	"bu": "A",		"n":"voltage","u":"V","v":120.1},
	"bver": 5,		{"n":"current","t":-5,"v":1.2},
	"n": "voltage", "u": "V", "v": 120.1 },		{"n":"current","t":-4,"v":1.3},
	{ "n": "current", "t": -5, "v": 1.2 },		{"n":"current","t":-3,"v":1.4},
	{ "n": "current", "t": -4, "v": 1.30 },		{"n":"current","t":-2,"v":1.5},
	{ "n": "current", "t": -3, "v": 0.14e1 },		{"n":"current","t":-1,"v":1.6},
	{ "n": "current", "t": -2, "v": 1.5 },		{"n":"current","v":1.7}
	{ "n": "current", "t": -1, "v": 1.6 },		]
	{ "n": "current", "t": 0, "v": 1.7 }
	]
	Note that in some usage scenarios of SenML the implementations MAY		Note that in some usage scenarios of SenML the implementations MAY
	store or transmit SenML in a stream-like fashion, where data is		store or transmit SenML in a stream-like fashion, where data is
	collected over time and continuously added to the object. This mode		collected over time and continuously added to the object. This mode
	of operation is optional, but systems or protocols using SenML in		of operation is optional, but systems or protocols using SenML in
	this fashion MUST specify that they are doing this. SenML defines a		this fashion MUST specify that they are doing this. SenML defines a
	separate media type to indicate Sensor Streaming Markup Language		separate media type to indicate Sensor Streaming Markup Language
	(SensML) for this usage (see Section 11.3.1). In this situation the		(SensML) for this usage (see Section 11.3.1). In this situation the
	SensML stream can be sent and received in a partial fashion, i.e., a		SensML stream can be sent and received in a partial fashion, i.e., a
	measurement entry can be read as soon as the SenML Record is received		measurement entry can be read as soon as the SenML Record is received
	and not have to wait for the full SensML Stream to be complete.		and not have to wait for the full SensML Stream to be complete.
	For instance, the following stream of measurements may be sent via a		For instance, the following stream of measurements may be sent via a
	long lived HTTP POST from the producer of a SensML to the consumer of		long lived HTTP POST from the producer of a SensML to the consumer of
	that, and each measurement object may be reported at the time it was		that, and each measurement object may be reported at the time it was
	measured:		measured:
	[ {"bn": "urn:dev:ow:10e2073a01080063",		[
	"bt": 1320067464,		{"bn":"urn:dev:ow:10e2073a01080063","bt":1.320067464e+09,"bu":"%RH","v":21.2},
	"bu": "%RH",		{"t":10,"v":21.3},
	"v": 21.2, "t": 0 },		{"t":20,"v":21.4},
	{ "v": 21.3, "t": 10 },		{"t":30,"v":21.4},
	{ "v": 21.4, "t": 20 },		{"t":40,"v":21.5},
	{ "v": 21.4, "t": 30 },		{"t":50,"v":21.5},
	{ "v": 21.5, "t": 40 },		{"t":60,"v":21.5},
	{ "v": 21.5, "t": 50 },		{"t":70,"v":21.6},
	{ "v": 21.5, "t": 60 },		{"t":80,"v":21.7},
	{ "v": 21.6, "t": 70 },		{"t":90,"v":21.5},
	{ "v": 21.7, "t": 80 },		...
	{ "v": 21.5, "t": 90 },
	...
	5.1.3. Multiple Measurements		5.1.3. Multiple Measurements
	The following example shows humidity measurements from a mobile		The following example shows humidity measurements from a mobile
	device with a 1-wire address 10e2073a01080063, starting at Mon Oct 31		device with a 1-wire address 10e2073a01080063, starting at Mon Oct 31
	13:24:24 UTC 2011. The device also provides position data, which is		13:24:24 UTC 2011. The device also provides position data, which is
	provided in the same measurement or parameter array as separate		provided in the same measurement or parameter array as separate
	entries. Note time is used to for correlating data that belongs		entries. Note time is used to for correlating data that belongs
	together, e.g., a measurement and a parameter associated with it.		together, e.g., a measurement and a parameter associated with it.
	Finally, the device also reports extra data about its battery status		Finally, the device also reports extra data about its battery status
	at a separate time.		at a separate time.
	[{"bn": "urn:dev:ow:10e2073a01080063",		[
	"bt": 1320067464,		{"bn":"urn:dev:ow:10e2073a01080063","bt":1.320067464e+09,"bu":"%RH","v":20},
	"bu": "%RH",		{"u":"lon","v":24.30621},
	"v": 20.0, "t": 0 },		{"u":"lat","v":60.07965},
	{ "v": 24.30621, "u": "lon", "t": 0 },		{"t":60,"v":20.3},
	{ "v": 60.07965, "u": "lat", "t": 0 },		{"u":"lon","t":60,"v":24.30622},
	{ "v": 20.3, "t": 60 },		{"u":"lat","t":60,"v":60.07965},
	{ "v": 24.30622, "u": "lon", "t": 60 },		{"t":120,"v":20.7},
	{ "v": 60.07965, "u": "lat", "t": 60 },		{"u":"lon","t":120,"v":24.30623},
	{ "v": 20.7, "t": 120 },		{"u":"lat","t":120,"v":60.07966},
	{ "v": 24.30623, "u": "lon", "t": 120 },		{"u":"%EL","t":150,"v":98},
	{ "v": 60.07966, "u": "lat", "t": 120 },		{"t":180,"v":21.2},
	{ "v": 98.0, "u": "%EL", "t": 150 },		{"u":"lon","t":180,"v":24.30628},
	{ "v": 21.2, "t": 180 },		{"u":"lat","t":180,"v":60.07967}
	{ "v": 24.30628, "u": "lon", "t": 180 },		]
	{ "v": 60.07967, "u": "lat", "t": 180 }
	]
	The size of this example represented in various forms, as well as		The size of this example represented in various forms, as well as
	that form compressed with gzip is given in the following table.		that form compressed with gzip is given in the following table.
	+----------+------+-----------------+		+----------+------+-----------------+
	| Encoding | Size | Compressed Size |		| Encoding | Size | Compressed Size |
	+----------+------+-----------------+		+----------+------+-----------------+
	| JSON | 573 | 206 |		| JSON | 573 | 206 |
	| XML | 649 | 235 |		| XML | 649 | 235 |
	| CBOR | 254 | 196 |		| CBOR | 254 | 196 |
	| EXI | 173 | 196 |		| EXI | 173 | 196 |
	+----------+------+-----------------+		+----------+------+-----------------+
	Table 2: Size Comparisons		Table 2: Size Comparisons
	Note the EXI sizes are not using the schema guidance so the EXI		Note the EXI sizes are not using the schema guidance so the EXI
	representation could be a bit smaller.		representation could be a bit smaller.
	5.1.4. Collection of Resources		5.1.4. Resolved Data
			The following shows the example from the previous section show in
			resolved format.
			[
			{"n":"urn:dev:ow:10e2073a01080063","u":"%RH","t":1.320067464e+09,"v":20},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lon","t":1.320067464e+09,"v":24.30621},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lat","t":1.320067464e+09,"v":60.07965},
			{"n":"urn:dev:ow:10e2073a01080063","u":"%RH","t":1.320067524e+09,"v":20.3},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lon","t":1.320067524e+09,"v":24.30622},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lat","t":1.320067524e+09,"v":60.07965},
			{"n":"urn:dev:ow:10e2073a01080063","u":"%RH","t":1.320067584e+09,"v":20.7},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lon","t":1.320067584e+09,"v":24.30623},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lat","t":1.320067584e+09,"v":60.07966},
			{"n":"urn:dev:ow:10e2073a01080063","u":"%EL","t":1.320067614e+09,"v":98},
			{"n":"urn:dev:ow:10e2073a01080063","u":"%RH","t":1.320067644e+09,"v":21.2},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lon","t":1.320067644e+09,"v":24.30628},
			{"n":"urn:dev:ow:10e2073a01080063","u":"lat","t":1.320067644e+09,"v":60.07967}
			]
			5.1.5. Multiple Data Types
			The following example shows a sensor that returns different data
			types.
			[
			{"bn":"urn:dev:ow:10e2073a01080063-","n":"temp","u":"Cel","v":23.1},
			{"n":"label","vs":"Machine Room"},
			{"n":"open","vb":false},
			{"n":"nfv-reader","vd":"aGkgCg=="}
			]
			5.1.6. Collection of Resources
	The following example shows how to query one device that can provide		The following example shows how to query one device that can provide
	multiple measurements. The example assumes that a client has fetched		multiple measurements. The example assumes that a client has fetched
	information from a device at 2001:db8::2 by performing a GET		information from a device at 2001:db8::2 by performing a GET
	operation on http://[2001:db8::2] at Mon Oct 31 16:27:09 UTC 2011,		operation on http://[2001:db8::2] at Mon Oct 31 16:27:09 UTC 2011,
	and has gotten two separate values as a result, a temperature and		and has gotten two separate values as a result, a temperature and
	humidity measurement.		humidity measurement.
	[{"bn": "http://[2001:db8::2]/",		[
	"bt": 1320078429,		{"bn":"http://[2001:db8::2]/","bt":1.320078429e+09,"bver":5,"n":"temperature",
	"bver": 5,		"u":"Cel","v":27.2},
	"n": "temperature", "v": 27.2, "u": "Cel" },		{"n":"humidity",
	{ "n": "humidity", "v": 80, "u": "%RH" }		"u":"%RH","v":80}
	]		]
	6. CBOR Representation (application/senml+cbor)		6. CBOR Representation (application/senml+cbor)
	The CBOR [RFC7049] representation is equivalent to the JSON		The CBOR [RFC7049] representation is equivalent to the JSON
	representation, with the following changes:		representation, with the following changes:
			o For JSON Numbers, the CBOR representation can use integers,
			floating point numbers, or decimal fractions (CBOR Tag 4); however
			a representation SHOULD be chosen such that when the CBOR value is
			converted back to an IEEE double precision floating point value,
			it has exactly the same value as the original Number. For the
			version number, only an unsigned integer is allowed.
			o Characters in the String Value are encoded using a definite length
			text string (type 3). Octets in the Data Value are encoded using
			a definite length byte string (type 2) .
	o For compactness, the CBOR representation uses integers for the map		o For compactness, the CBOR representation uses integers for the map
	keys defined in Table 3. This table is conclusive, i.e., there is		keys defined in Table 3. This table is conclusive, i.e., there is
	no intention to define any additional integer map keys; any		no intention to define any additional integer map keys; any
	extensions will use string map keys.		extensions will use string map keys.
	o For JSON Numbers, the CBOR representation can use integers,		+---------------+-------+------------+
	floating point numbers, or decimal fractions (CBOR Tag 4); the		| Name | Label | CBOR Label |
	common limitations of JSON implementations are not relevant for		+---------------+-------+------------+
	these. For the version number, however, only an unsigned integer		| Version | bver | -1 |
	is allowed.		| Base Name | bn | -2 |
			| Base Time | bt | -3 |
	+---------------+------------+------------+		| Base Units | bu | -4 |
	| Name | JSON label | CBOR label |		| Base Value | bv | -5 |
	+---------------+------------+------------+		| Base Sum | bs | -6 |
	| Version | bver | -1 |		| Name | n | 0 |
	| Base Name | bn | -2 |		| Units | u | 1 |
	| Base Time | bt | -3 |		| Value | v | 2 |
	| Base Units | bu | -4 |		| String Value | vs | 3 |
	| Base Value | bv | -5 |		| Boolean Value | vb | 4 |
	| Name | n | 0 |		| Value Sum | s | 5 |
	| Units | u | 1 |		| Time | t | 6 |
	| Value | v | 2 |		| Update Time | ut | 7 |
	| String Value | vs | 3 |		| Data Value | vd | 8 |
	| Boolean Value | vb | 4 |		| Link | l | 9 |
	| Value Sum | s | 5 |		+---------------+-------+------------+
	| Time | t | 6 |
	| Update Time | ut | 7 |
	| Data Value | vd | 8 |
	+---------------+------------+------------+
	Table 3: CBOR representation: integers for map keys		Table 3: CBOR representation: integers for map keys
			o For streaming SensML in CBOR representation, the array containing
			the records SHOULD be an CBOR indefinite length array while for
			non streaming SenML, a definite length array MUST be used.
	The following example shows a dump of the CBOR example for the same		The following example shows a dump of the CBOR example for the same
	sensor measurement as in Section 5.1.2.		sensor measurement as in Section 5.1.2.
	0000 87 a7 21 78 1c 75 72 6e 3a 64 65 76 3a 6f 77 3a |..!x.urn:dev:ow:|		0000 87 a7 21 78 1c 75 72 6e 3a 64 65 76 3a 6f 77 3a |..!x.urn:dev:ow:|
	0010 31 30 65 32 30 37 33 61 30 31 30 38 30 30 36 33 |10e2073a01080063|		0010 31 30 65 32 30 37 33 61 30 31 30 38 30 30 36 33 |10e2073a01080063|
	0020 2f 22 fb 41 d3 03 a1 5b 00 10 62 23 61 41 20 05 |/".A...[..b#aA .|		0020 2f 22 fb 41 d3 03 a1 5b 00 10 62 23 61 41 20 05 |/".A...[..b#aA .|
	0030 00 67 76 6f 6c 74 61 67 65 01 61 56 02 fb 40 5e |.gvoltage.aV..@^|		0030 00 67 76 6f 6c 74 61 67 65 01 61 56 02 fb 40 5e |.gvoltage.aV..@^|
	0040 06 66 66 66 66 66 a3 00 67 63 75 72 72 65 6e 74 |.fffff..gcurrent|		0040 06 66 66 66 66 66 a3 00 67 63 75 72 72 65 6e 74 |.fffff..gcurrent|
	0050 06 24 02 fb 3f f3 33 33 33 33 33 33 a3 00 67 63 |.$..?.333333..gc|		0050 06 24 02 fb 3f f3 33 33 33 33 33 33 a3 00 67 63 |.$..?.333333..gc|
	0060 75 72 72 65 6e 74 06 23 02 fb 3f f4 cc cc cc cc |urrent.#..?.....|		0060 75 72 72 65 6e 74 06 23 02 fb 3f f4 cc cc cc cc |urrent.#..?.....|
	skipping to change at page 13, line 47 ¶		skipping to change at page 15, line 8 ¶
	0080 3f f6 66 66 66 66 66 66 a3 00 67 63 75 72 72 65 |?.ffffff..gcurre|		0080 3f f6 66 66 66 66 66 66 a3 00 67 63 75 72 72 65 |?.ffffff..gcurre|
	0090 6e 74 06 21 02 f9 3e 00 a3 00 67 63 75 72 72 65 |nt.!..>...gcurre|		0090 6e 74 06 21 02 f9 3e 00 a3 00 67 63 75 72 72 65 |nt.!..>...gcurre|
	00a0 6e 74 06 20 02 fb 3f f9 99 99 99 99 99 9a a3 00 |nt. ..?.........|		00a0 6e 74 06 20 02 fb 3f f9 99 99 99 99 99 9a a3 00 |nt. ..?.........|
	00b0 67 63 75 72 72 65 6e 74 06 00 02 fb 3f fb 33 33 |gcurrent....?.33|		00b0 67 63 75 72 72 65 6e 74 06 00 02 fb 3f fb 33 33 |gcurrent....?.33|
	00c0 33 33 33 33 |3333|		00c0 33 33 33 33 |3333|
	00c4		00c4
	7. XML Representation (application/senml+xml)		7. XML Representation (application/senml+xml)
	A SenML Pack or Stream can also be represented in XML format as		A SenML Pack or Stream can also be represented in XML format as
	defined in this section. The following example shows an XML example		defined in this section.
	for the same sensor measurement as in Section 5.1.2.
			Only the UTF-8 form of XML is allowed. Characters in the String
			Value are encoded using the escape sequences defined in [RFC7159].
			Octets in the Data Value are base64 encoded with URL safe alphabet as
			defined in Section 5 of [RFC4648].
			The following example shows an XML example for the same sensor
			measurement as in Section 5.1.2.
	<sensml xmlns="urn:ietf:params:xml:ns:senml">		<sensml xmlns="urn:ietf:params:xml:ns:senml">
	<senml bn="urn:dev:ow:10e2073a01080063/" bt="1.276020076001e+09"		<senml bn="urn:dev:ow:10e2073a01080063/" bt="1.276020076001e+09"
	bu="A" bver="5" n="voltage" u="V" v="120.1"></senml>		bu="A" bver="5" n="voltage" u="V" v="120.1"></senml>
	<senml n="current" t="-5" v="1.2"></senml>		<senml n="current" t="-5" v="1.2"></senml>
	<senml n="current" t="-4" v="1.3"></senml>		<senml n="current" t="-4" v="1.3"></senml>
	<senml n="current" t="-3" v="1.4"></senml>		<senml n="current" t="-3" v="1.4"></senml>
	<senml n="current" t="-2" v="1.5"></senml>		<senml n="current" t="-2" v="1.5"></senml>
	<senml n="current" t="-1" v="1.6"></senml>		<senml n="current" t="-1" v="1.6"></senml>
	<senml n="current" v="1.7"></senml>		<senml n="current" v="1.7"></senml>
	</sensml>		</sensml>
	The SenML Stream is represented as a sensml tag that contains a		The SenML Stream is represented as a sensml tag that contains a
	series of senml tags for each SenML Record. The SenML Fields are		series of senml tags for each SenML Record. The SenML Fields are
	represents as XML attributes. The following table shows the mapping		represents as XML attributes. The following table shows the mapping
	of the SenML labels to the attribute names and types used in the XML		of the SenML labels, which are used for the attribute name, to the
	senml tags.		attribute types used in the XML senml tags.
	+---------------+------+---------+		+---------------+-------+---------+
	| Name | XML | Type |		| Name | Label | Type |
	+---------------+------+---------+		+---------------+-------+---------+
	| Base Name | bn | string |		| Base Name | bn | string |
	| Base Time | bt | double |		| Base Time | bt | double |
	| Base Unit | bu | string |		| Base Unit | bu | string |
	| Base Value | bv | double |		| Base Value | bv | double |
	| Base Version | bver | int |		| Base Sum | bs | double |
	| Name | n | string |		| Base Version | bver | int |
	| Unit | u | string |		| Name | n | string |
	| Value | v | double |		| Unit | u | string |
	| String Value | vs | string |		| Value | v | double |
	| Data Value | vd | string |		| String Value | vs | string |
	| Boolean Value | vb | boolean |		| Data Value | vd | string |
	| Value Sum | s | double |		| Boolean Value | vb | boolean |
	| Time | t | double |		| Value Sum | s | double |
	| Update Time | ut | double |		| Time | t | double |
	+---------------+------+---------+		| Update Time | ut | double |
			| Link | l | string |
			+---------------+-------+---------+
	Table 4: XML SenML Labels		Table 4: XML SenML Labels
	The RelaxNG schema for the XML is:		The RelaxNG schema for the XML is:
	default namespace = "urn:ietf:params:xml:ns:senml"		default namespace = "urn:ietf:params:xml:ns:senml"
	namespace rng = "http://relaxng.org/ns/structure/1.0"		namespace rng = "http://relaxng.org/ns/structure/1.0"
	senml = element senml {		senml = element senml {
	attribute bn { xsd:string }?,		attribute bn { xsd:string }?,
	attribute bt { xsd:double }?,		attribute bt { xsd:double }?,
	attribute bv { xsd:double }?,		attribute bv { xsd:double }?,
			attribute bs { xsd:double }?,
	attribute bu { xsd:string }?,		attribute bu { xsd:string }?,
	attribute bver { xsd:int }?,		attribute bver { xsd:int }?,
			attribute l { xsd:string }?,
	attribute n { xsd:string }?,		attribute n { xsd:string }?,
	attribute s { xsd:double }?,		attribute s { xsd:double }?,
	attribute t { xsd:double }?,		attribute t { xsd:double }?,
	attribute u { xsd:string }?,		attribute u { xsd:string }?,
	attribute ut { xsd:double }?,		attribute ut { xsd:double }?,
	attribute v { xsd:double }?,		attribute v { xsd:double }?,
	attribute vb { xsd:boolean }?,		attribute vb { xsd:boolean }?,
	attribute vs { xsd:string }?,		attribute vs { xsd:string }?,
	attribute vd { xsd:string }?		attribute vd { xsd:string }?
	}		}
	sensml =		sensml =
	element sensml {		element sensml {
	senml+		senml+
	}		}
	start = sensml		start = sensml
	8. EXI Representation (application/senml-exi)		8. EXI Representation (application/senml+exi)
	For efficient transmission of SenML over e.g. a constrained network,		For efficient transmission of SenML over e.g. a constrained network,
	Efficient XML Interchange (EXI) can be used. This encodes the XML		Efficient XML Interchange (EXI) can be used. This encodes the XML
	Schema structure of SenML into binary tags and values rather than		Schema structure of SenML into binary tags and values rather than
	ASCII text. An EXI representation of SenML SHOULD be made using the		ASCII text. An EXI representation of SenML SHOULD be made using the
	strict schema-mode of EXI. This mode however does not allow tag		strict schema-mode of EXI. This mode however does not allow tag
	extensions to the schema, and therefore any extensions will be lost		extensions to the schema, and therefore any extensions will be lost
	in the encoding. For uses where extensions need to be preserved in		in the encoding. For uses where extensions need to be preserved in
	EXI, the non-strict schema mode of EXI MAY be used.		EXI, the non-strict schema mode of EXI MAY be used.
	The EXI header option MUST be included. An EXI schemaID options MUST		The EXI header option MUST be included. An EXI schemaID options MUST
	be set to the value of "a" indicating the scheme provided in this		be set to the value of "a" indicating the scheme provided in this
	specification. Future revisions to the schema can change this		specification. Future revisions to the schema can change this
	schemaID to allow for backwards compatibility. When the data will be		schemaID to allow for backwards compatibility. When the data will be
	transported over CoAP or HTTP, an EXI Cookie SHOULD NOT be used as it		transported over CoAP or HTTP, an EXI Cookie SHOULD NOT be used as it
	simply makes things larger and is redundant to information provided		simply makes things larger and is redundant to information provided
	in the Content-Type header.		in the Content-Type header.
	TODO - examples probably have the wrong setting for the schemaID
	The following is the XSD Schema to be used for strict schema guided		The following is the XSD Schema to be used for strict schema guided
	EXI processing. It is generated from the RelaxNG.		EXI processing. It is generated from the RelaxNG.
	<?xml version="1.0" encoding="utf-8"?>		<?xml version="1.0" encoding="utf-8"?>
	<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"		<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
	elementFormDefault="qualified"		elementFormDefault="qualified"
	targetNamespace="urn:ietf:params:xml:ns:senml"		targetNamespace="urn:ietf:params:xml:ns:senml"
	xmlns:ns1="urn:ietf:params:xml:ns:senml">		xmlns:ns1="urn:ietf:params:xml:ns:senml">
	<xs:element name="senml">		<xs:element name="senml">
	<xs:complexType>		<xs:complexType>
	<xs:attribute name="bn" type="xs:string" />		<xs:attribute name="bn" type="xs:string" />
	<xs:attribute name="bt" type="xs:double" />		<xs:attribute name="bt" type="xs:double" />
	<xs:attribute name="bv" type="xs:double" />		<xs:attribute name="bv" type="xs:double" />
	<xs:attribute name="bu" type="xs:string" />		<xs:attribute name="bu" type="xs:string" />
	<xs:attribute name="bver" type="xs:int" />		<xs:attribute name="bver" type="xs:int" />
			<xs:attribute name="l" type="xs:string" />
	<xs:attribute name="n" type="xs:string" />		<xs:attribute name="n" type="xs:string" />
	<xs:attribute name="s" type="xs:double" />		<xs:attribute name="s" type="xs:double" />
	<xs:attribute name="t" type="xs:double" />		<xs:attribute name="t" type="xs:double" />
	<xs:attribute name="u" type="xs:string" />		<xs:attribute name="u" type="xs:string" />
	<xs:attribute name="ut" type="xs:double" />		<xs:attribute name="ut" type="xs:double" />
	<xs:attribute name="v" type="xs:double" />		<xs:attribute name="v" type="xs:double" />
	<xs:attribute name="vb" type="xs:boolean" />		<xs:attribute name="vb" type="xs:boolean" />
	<xs:attribute name="vs" type="xs:string" />		<xs:attribute name="vs" type="xs:string" />
	<xs:attribute name="vd" type="xs:string" />		<xs:attribute name="vd" type="xs:string" />
	</xs:complexType>		</xs:complexType>
	skipping to change at page 17, line 7 ¶		skipping to change at page 19, line 15 ¶
	<sensml xmlns="urn:ietf:params:xml:ns:senml">		<sensml xmlns="urn:ietf:params:xml:ns:senml">
	<senml bn="urn:dev:ow:10e2073a01080063" n="voltage" u="V"		<senml bn="urn:dev:ow:10e2073a01080063" n="voltage" u="V"
	v="120.1"></senml>		v="120.1"></senml>
	<senml n="current" u="A" v="1.2"></senml>		<senml n="current" u="A" v="1.2"></senml>
	</sensml>		</sensml>
	Which compresses with EXI to the following displayed in hexdump:		Which compresses with EXI to the following displayed in hexdump:
	0000 a0 30 3d cd 95 b9 b5 b0 b9 9d 95 b8 b9 e1 cd 90 |.0=.............|		0000 a0 30 3d cd 95 b9 b5 b0 b9 9d 95 b8 b9 e1 cd 90 |.0=.............|
	0010 80 eb ab 93 71 d3 23 2b b1 d3 7b b9 d1 89 83 29 |....q.#+..{....)|		0010 80 eb ab 93 71 d3 23 2b b1 d3 7b b9 d1 89 83 29 |....q.#+..{....)|
	0020 91 81 b9 9b 09 81 89 81 c1 81 81 b1 9a 84 bb 37 |...............7|		0020 91 81 b9 9b 09 81 89 81 c1 81 81 b1 9a 04 bb 37 |...............7|
	0030 b6 3a 30 b3 b2 90 1a b1 58 84 c0 33 04 b1 ba b9 |.:0.....X..3....|		0030 b6 3a 30 b3 b2 90 1a b1 58 84 c0 32 84 b1 ba b9 |.:0.....X..2....|
	0040 39 32 b7 3a 10 1a 09 06 40 38 |92.:....@8|		0040 39 32 b7 3a 10 1a 09 06 40 38 |92.:....@8|
	004a		004a
	The above example used the bit packed form of EXI but it is also		The above example used the bit packed form of EXI but it is also
	possible to use a byte packed form of EXI which can makes it easier		possible to use a byte packed form of EXI which can makes it easier
	for a simple sensor to produce valid EXI without really implementing		for a simple sensor to produce valid EXI without really implementing
	EXI. Consider the example of a temperature sensor that produces a		EXI. Consider the example of a temperature sensor that produces a
	value in tenths of degrees Celsius over a range of 0.0 to 55.0. It		value in tenths of degrees Celsius over a range of 0.0 to 55.0. It
	would produce an XML SenML file such as:		would produce an XML SenML file such as:
	<sensml xmlns="urn:ietf:params:xml:ns:senml">		<sensml xmlns="urn:ietf:params:xml:ns:senml">
	<senml n="urn:dev:ow:10e2073a01080063" u="Cel" v="23.1"></senml>		<senml n="urn:dev:ow:10e2073a01080063" u="Cel" v="23.1"></senml>
	</sensml>		</sensml>
	The compressed form, using the byte alignment option of EXI, for the		The compressed form, using the byte alignment option of EXI, for the
	above XML is the following:		above XML is the following:
	0000 a0 00 48 81 ee 6c ad cd ad 85 cc ec ad c5 cf 0e |..H..l..........|		0000 a0 00 48 81 ee 6c ad cd ad 85 cc ec ad c5 cf 0e |..H..l..........|
	0010 6c 80 01 06 1d 75 72 6e 3a 64 65 76 3a 6f 77 3a |l....urn:dev:ow:|		0010 6c 80 01 05 1d 75 72 6e 3a 64 65 76 3a 6f 77 3a |l....urn:dev:ow:|
	0020 31 30 65 32 30 37 33 61 30 31 30 38 30 30 36 33 |10e2073a01080063|		0020 31 30 65 32 30 37 33 61 30 31 30 38 30 30 36 33 |10e2073a01080063|
	0030 02 05 43 65 6c 01 00 e7 01 01 00 03 01 |..Cel........|		0030 02 05 43 65 6c 01 00 e7 01 01 00 03 01 |..Cel........|
	003d		003d
	A small temperature sensor devices that only generates this one EXI		A small temperature sensor devices that only generates this one EXI
	file does not really need an full EXI implementation. It can simply		file does not really need an full EXI implementation. It can simply
	hard code the output replacing the 1-wire device ID starting at byte		hard code the output replacing the 1-wire device ID starting at byte
	0x20 and going to byte 0x2F with it's device ID, and replacing the		0x20 and going to byte 0x2F with it's device ID, and replacing the
	value "0xe7 0x01" at location 0x37 and 0x38 with the current		value "0xe7 0x01" at location 0x37 and 0x38 with the current
	temperature. The EXI Specification [W3C.REC-exi-20110310] contains		temperature. The EXI Specification [W3C.REC-exi-20110310] contains
	skipping to change at page 20, line 18 ¶		skipping to change at page 22, line 27 ¶
	Figure 1: Common CDDL specification for CBOR and JSON SenML		Figure 1: Common CDDL specification for CBOR and JSON SenML
	For JSON, we use text labels and base64url-encoded binary data		For JSON, we use text labels and base64url-encoded binary data
	(Figure 2).		(Figure 2).
	bver = "bver" n = "n" s = "s"		bver = "bver" n = "n" s = "s"
	bn = "bn" u = "u" t = "t"		bn = "bn" u = "u" t = "t"
	bt = "bt" v = "v" ut = "ut"		bt = "bt" v = "v" ut = "ut"
	bu = "bu" vs = "vs" vd = "vd"		bu = "bu" vs = "vs" vd = "vd"
	bv = "bv" vb = "vb"		bv = "bv" vb = "vb" l = "l"
	binary-value = tstr ; base64url encoded		binary-value = tstr ; base64url encoded
	Figure 2: JSON-specific CDDL specification for SenML		Figure 2: JSON-specific CDDL specification for SenML
	For CBOR, we use integer labels and native binary data (Figure 3).		For CBOR, we use integer labels and native binary data (Figure 3).
	bver = -1 n = 0 s = 5		bver = -1 n = 0 s = 5
	bn = -2 u = 1 t = 6		bn = -2 u = 1 t = 6
	bt = -3 v = 2 ut = 7		bt = -3 v = 2 ut = 7
	bu = -4 vs = 3 vd = 8		bu = -4 vs = 3 vd = 8
	bv = -5 vb = 4		bv = -5 vb = 4 l = 9
	binary-value = bstr		binary-value = bstr
	Figure 3: CBOR-specific CDDL specification for SenML		Figure 3: CBOR-specific CDDL specification for SenML
	11. IANA Considerations		11. IANA Considerations
	Note to RFC Editor: Please replace all occurrences of "RFC-AAAA" with		Note to RFC Editor: Please replace all occurrences of "RFC-AAAA" with
	the RFC number of this specification.		the RFC number of this specification.
	skipping to change at page 24, line 5 ¶		skipping to change at page 26, line 13 ¶
	allocated.		allocated.
	10. A number after a unit typically indicates the previous unit		10. A number after a unit typically indicates the previous unit
	raised to that power, and the / indicates that the units that		raised to that power, and the / indicates that the units that
	follow are the reciprocal. A unit should have only one / in the		follow are the reciprocal. A unit should have only one / in the
	name.		name.
	11. A good list of common units can be found in the Unified Code for		11. A good list of common units can be found in the Unified Code for
	Units of Measure [UCUM].		Units of Measure [UCUM].
	11.2. SenML label registry		11.2. SenML Label Registry
	IANA will create a new registry for SenML labels. The initial		IANA will create a new registry for SenML labels. The initial
	content of the registry are shown in Table 1 and Table 4.		content of the registry is:
			+---------------+-------+------+----------+----+---------+
			| Name | Label | CBOR | XML Type | ID | Note |
			+---------------+-------+------+----------+----+---------+
			| Base Name | bn | -2 | string | a | RFCXXXX |
			| Base Sum | bs | -6 | double | a | RFCXXXX |
			| Base Time | bt | -3 | double | a | RFCXXXX |
			| Base Unit | bu | -4 | string | a | RFCXXXX |
			| Base Value | bv | -5 | double | a | RFCXXXX |
			| Base Version | bver | -1 | int | a | RFCXXXX |
			| Boolean Value | vb | 4 | boolean | a | RFCXXXX |
			| Data Value | vd | 8 | string | a | RFCXXXX |
			| Name | n | 0 | string | a | RFCXXXX |
			| String Value | vs | 3 | string | a | RFCXXXX |
			| Time | t | 6 | double | a | RFCXXXX |
			| Unit | u | 1 | string | a | RFCXXXX |
			| Update Time | ut | 7 | double | a | RFCXXXX |
			| Value | v | 2 | double | a | RFCXXXX |
			| Value Sum | s | 5 | double | a | RFCXXXX |
			| Link | l | 9 | string | a | RFCXXXX |
			+---------------+-------+------+----------+----+---------+
			Table 6: SenML Labels
			Note to RFC Editor. Please replace RFCXXXX with the number for this
			RFC.
			All new entries must define the Label Name, Label, and XML Type but
			the CBOR labels SHOULD be left empty as CBOR will use the string
			encoding for any new labels. The ID fields contains the EXI schemaID
			of the first Schema which includes this label or is empty if this
			label was not intended for use with EXI. The Note field SHOULD
			contain information about where to find out more information about
			this label.
			The JSON, CBOR, and EXI types are derived from the XML type. All XML
			numeric types such as double, float, integer and int become a JSON
			Number. XML boolean and string become a JSON Boolean and String
			respectively. CBOR represents numeric values with a CBOR type that
			does not loose any information from the JSON value. EXI uses the XML
			types.
	New entries can be added to the registration by either Expert Review		New entries can be added to the registration by either Expert Review
	or IESG Approval as defined in [RFC5226]. Experts should exercise		or IESG Approval as defined in [RFC5226]. Experts should exercise
	their own good judgment but need to consider that shorter labels		their own good judgment but need to consider that shorter labels
	should have more strict review.		should have more strict review.
	All new SenML labels that have "base" semantics (see Section 4.1)		All new SenML labels that have "base" semantics (see Section 4.1)
	must start with character 'b'. Regular labels must not start with		MUST start with character 'b'. Regular labels MUST NOT start with
	that character.		that character.
	All new entries must define the Label Name, Label, JSON Type, and XML		Extensions that add a label that is intended for use with XML need to
	Type.		create a new RelaxNG scheme that includes all the labels in the IANA
			registry.
			Extensions that add a label that is intended for use with EXI need to
			create a new XSD Schema that includes all the labels in the IANA
			registry then allocate a new EXI schemaID. Moving to the next letter
			in the alphabet is the suggested way to create the new EXI schemaID.
			Any labels with previously blank ID values SHOULD be updated in the
			IANA table to have their ID set to this new schemaID value.
	11.3. Media Type Registration		11.3. Media Type Registration
	The following registrations are done following the procedure		The following registrations are done following the procedure
	specified in [RFC6838] and [RFC7303].		specified in [RFC6838] and [RFC7303].
			Note to RFC Editor - please remove this paragraph. Note that a
			request for media type review for senml+json was sent to the media-
			types@iana.org on Sept 21, 2010. A second request for all the types
			was sent on TODO.
	11.3.1. senml+json Media Type Registration		11.3.1. senml+json Media Type Registration
	Type name: application		Type name: application
	Subtype name: senml+json and sensml+json		Subtype name: senml+json and sensml+json
	Required parameters: none		Required parameters: none
	Optional parameters: none		Optional parameters: none
	Encoding considerations: Must be encoded as using a subset of the		Encoding considerations: Must be encoded as using a subset of the
	encoding allowed in [RFC7159]. See RFC-AAAA for details. This		encoding allowed in [RFC7159]. See RFC-AAAA for details. This
	simplifies implementation of very simple system and does not impose		simplifies implementation of very simple system and does not impose
	any significant limitations as all this data is meant for machine to		any significant limitations as all this data is meant for machine to
	machine communications and is not meant to be human readable.		machine communications and is not meant to be human readable.
	Security considerations: Sensor data can contain a wide range of		Security considerations: Sensor data can contain a wide range of
	information ranging from information that is very public, such the		information ranging from information that is very public, such the
	outside temperature in a given city, to very private information that		outside temperature in a given city, to very private information that
	requires integrity and confidentiality protection, such as patient		requires integrity and confidentiality protection, such as patient
	skipping to change at page 27, line 17 ¶		skipping to change at page 30, line 33 ¶
	Jennings <fluffy@iii.ca>		Jennings <fluffy@iii.ca>
	Intended usage: COMMON		Intended usage: COMMON
	Restrictions on usage: None		Restrictions on usage: None
	Author: Cullen Jennings <fluffy@iii.ca>		Author: Cullen Jennings <fluffy@iii.ca>
	Change controller: IESG		Change controller: IESG
	11.3.4. senml-exi Media Type Registration		11.3.4. senml+exi Media Type Registration
	Type name: application		Type name: application
	Subtype name: senml-exi and sensml-exi		Subtype name: senml+exi and sensml+exi
	Required parameters: none		Required parameters: none
	Optional parameters: none		Optional parameters: none
	Encoding considerations: TBD		Encoding considerations: TBD
	Security considerations: TBD		Security considerations: TBD
	Interoperability considerations: TBD		Interoperability considerations: TBD
	skipping to change at page 28, line 24 ¶		skipping to change at page 31, line 39 ¶
	Registrant Contact: The IESG.		Registrant Contact: The IESG.
	XML: N/A, the requested URIs are XML namespaces		XML: N/A, the requested URIs are XML namespaces
	11.5. CoAP Content-Format Registration		11.5. CoAP Content-Format Registration
	IANA is requested to assign CoAP Content-Format IDs for the SenML		IANA is requested to assign CoAP Content-Format IDs for the SenML
	media types in the "CoAP Content-Formats" sub-registry, within the		media types in the "CoAP Content-Formats" sub-registry, within the
	"CoRE Parameters" registry [RFC7252]. All IDs are assigned from the		"CoRE Parameters" registry [RFC7252]. All IDs are assigned from the
	"Expert Review" (0-255) range. The assigned IDs are show in Table 6.		"Expert Review" (0-255) range. The assigned IDs are show in Table 7.
	+-------------------------+-----+		+-------------------------+-----+
	| Media type | ID |		| Media type | ID |
	+-------------------------+-----+		+-------------------------+-----+
	| application/senml+json | TBD |		| application/senml+json | TBD |
	| application/sensml+json | TBD |		| application/sensml+json | TBD |
	| application/senml+cbor | TBD |		| application/senml+cbor | TBD |
			| application/sensml+cbor | TBD |
	| application/senml+xml | TBD |		| application/senml+xml | TBD |
	| application/sensml+xml | TBD |		| application/sensml+xml | TBD |
	| application/senml-exi | TBD |		| application/senml+exi | TBD |
			| application/sensml+exi | TBD |
	+-------------------------+-----+		+-------------------------+-----+
	Table 6: CoAP Content-Format IDs		Table 7: CoAP Content-Format IDs
	12. Security Considerations		12. Security Considerations
	See Section 13. Further discussion of security properties can be		See Section 13. Further discussion of security properties can be
	found in Section 11.3.		found in Section 11.3.
	13. Privacy Considerations		13. Privacy Considerations
	Sensor data can range from information with almost no security		Sensor data can range from information with almost no security
	considerations, such as the current temperature in a given city, to		considerations, such as the current temperature in a given city, to
	highly sensitive medical or location data. This specification		highly sensitive medical or location data. This specification
	provides no security protection for the data but is meant to be used		provides no security protection for the data but is meant to be used
	inside another container or transport protocol such as S/MIME or HTTP		inside another container or transport protocol such as S/MIME or HTTP
	with TLS that can provide integrity, confidentiality, and		with TLS that can provide integrity, confidentiality, and
	authentication information about the source of the data.		authentication information about the source of the data.
	14. Acknowledgement		14. Acknowledgement
	We would like to thank Lisa Dusseault, Joe Hildebrand, Lyndsay		We would like to thank Lisa Dusseault, Joe Hildebrand, Lyndsay
	Campbell, Martin Thomson, John Klensin, Bjoern Hoehrmann, and		Campbell, Martin Thomson, John Klensin, Bjoern Hoehrmann, Christian
	Christian Amsuess for their review comments.		Groves, and Christian Amsuess, for their review comments.
	15. References		15. References
	15.1. Normative References		15.1. Normative References
	[BIPM] Bureau International des Poids et Mesures, "The		[BIPM] Bureau International des Poids et Mesures, "The
	International System of Units (SI)", 8th edition, 2006.		International System of Units (SI)", 8th edition, 2006.
	[IEEE.754.1985]		[IEEE.754.1985]
	Institute of Electrical and Electronics Engineers,		Institute of Electrical and Electronics Engineers,
	skipping to change at page 30, line 42 ¶		skipping to change at page 34, line 25 ¶
	Names for Device Identifiers", draft-arkko-core-dev-urn-03		Names for Device Identifiers", draft-arkko-core-dev-urn-03
	(work in progress), July 2012.		(work in progress), July 2012.
	[I-D.greevenbosch-appsawg-cbor-cddl]		[I-D.greevenbosch-appsawg-cbor-cddl]
	Vigano, C. and H. Birkholz, "CBOR data definition language		Vigano, C. and H. Birkholz, "CBOR data definition language
	(CDDL): a notational convention to express CBOR data		(CDDL): a notational convention to express CBOR data
	structures", draft-greevenbosch-appsawg-cbor-cddl-08 (work		structures", draft-greevenbosch-appsawg-cbor-cddl-08 (work
	in progress), March 2016.		in progress), March 2016.
	[I-D.ietf-core-links-json]		[I-D.ietf-core-links-json]
	Li, K., Rahman, A., and D. Bormann, "Representing CoRE		Li, K., Rahman, A., and C. Bormann, "Representing CoRE
	Formats in JSON and CBOR", draft-ietf-core-links-json-05		Formats in JSON and CBOR", draft-ietf-core-links-json-06
	(work in progress), April 2016.		(work in progress), July 2016.
	[RFC2141] Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141,		[RFC2141] Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141,
	May 1997, <http://www.rfc-editor.org/info/rfc2141>.		May 1997, <http://www.rfc-editor.org/info/rfc2141>.
	[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform		[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
	Resource Identifier (URI): Generic Syntax", STD 66, RFC		Resource Identifier (URI): Generic Syntax", STD 66, RFC
	3986, DOI 10.17487/RFC3986, January 2005,		3986, DOI 10.17487/RFC3986, January 2005,
	<http://www.rfc-editor.org/info/rfc3986>.		<http://www.rfc-editor.org/info/rfc3986>.
	[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally		[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
	skipping to change at page 31, line 29 ¶		skipping to change at page 35, line 15 ¶
	[RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy		[RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy
	Considerations for IPv6 Address Generation Mechanisms",		Considerations for IPv6 Address Generation Mechanisms",
	RFC 7721, DOI 10.17487/RFC7721, March 2016,		RFC 7721, DOI 10.17487/RFC7721, March 2016,
	<http://www.rfc-editor.org/info/rfc7721>.		<http://www.rfc-editor.org/info/rfc7721>.
	[UCUM] Schadow, G. and C. McDonald, "The Unified Code for Units		[UCUM] Schadow, G. and C. McDonald, "The Unified Code for Units
	of Measure (UCUM)", Regenstrief Institute and Indiana		of Measure (UCUM)", Regenstrief Institute and Indiana
	University School of Informatics, 2013,		University School of Informatics, 2013,
	<http://unitsofmeasure.org/ucum.html>.		<http://unitsofmeasure.org/ucum.html>.
	Appendix A. Links extension		Appendix A. Links Extension
	An extension to SenML to support links is expected to be registered		An attribute to support a link extension for SenML is defined as a
	and defined by [I-D.ietf-core-links-json].		string attribute by this specification. The link extension can be
			used for additional information about a SenML Record. The definition
			and usage of the contents of this value are specified in
			[I-D.ietf-core-links-json].
	The link extension can be an array of objects that can be used for		For JSON and XML the attribute has a label of "l" and a value that is
	additional information. Each object in the Link array is constrained		a string.
	to being a map of strings to strings with unique keys.
	The following shows an example of the links extension.		The following shows an example of the links extension.
	[{"bn": "urn:dev:ow:10e2073a01080063/",		[
	"bt": 1320078429,		{"bn":"urn:dev:ow:10e2073a01080063/","bt":1.320078429e+09,
	"l": "[{\"href\":\"humidity\",\"foo\":\"bar1\"}",		"l":"[{\"href\":\"humidity\",\"foo\":\"bar1\"}",
	"n": "temperature", "v": 27.2, "u": "Cel" },		"n":"temperature","u":"Cel","v":27.2},
	{ "n": "humidity", "v": 80, "u": "%RH" }		{"n":"humidity","u":"%RH","v":80}
	]		]
	Authors' Addresses		Authors' Addresses
	Cullen Jennings		Cullen Jennings
	Cisco		Cisco
	400 3rd Avenue SW		400 3rd Avenue SW
	Calgary, AB T2P 4H2		Calgary, AB T2P 4H2
	Canada		Canada
	Phone: +1 408 421-9990		Phone: +1 408 421-9990
	Email: fluffy@iii.ca		Email: fluffy@iii.ca
	Zach Shelby		Zach Shelby
	ARM		ARM
	150 Rose Orchard		150 Rose Orchard
	San Jose 95134		San Jose 95134
	USA		USA
	Phone: +1-408-203-9434		Phone: +1-408-203-9434
	Email: zach.shelby@arm.com		Email: zach.shelby@arm.com
	Jari Arkko		Jari Arkko
End of changes. 61 change blocks.
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