[IPP] Attributes needed for Cloud Printing and definition inconsistencies [typo in definition of "longitude": "south" should be "west"]

[IPP] Attributes needed for Cloud Printing and definition inconsistencies [typo in definition of "longitude": "south" should be "west"]

Tom Hastings tom.hastings at verizon.net
Sun Jul 25 22:00:34 UTC 2010


Pete,

 

I assume that there is a typo in the definition of "longitude".  The
sentence:

 

Values above that are east and below are south

should be:

Values above that are east and below are west

 

Here are the two descriptions of the two new attributes for "latitude" and
"longitude":

 

*new*

latitude (SM:Latitude):  The latitude of the center of the sphere described
by the size attribute.  Expressed in thousandths of a second of arc.  The
value 2147483648  (231) represents the equator.  Values above that are north
and below are south.   Datatype: abstract: int32, IPP:integer, SM:xs:int

 

*new*

longitude (SM:Latitude):  The longitude of the center of the sphere
described by the size attribute.  Expressed in thousandths of a second of
arc.  The value 2147483648  (231) represents the prime meridian.  Values
above that are east and below are south.  The value is rounded away from the
prime meridian   Datatype: abstract: int32, IPP:integer, SM:xs:int

 

Tom

 

  _____  

From: ipp-bounces at pwg.org [mailto:ipp-bounces at pwg.org] On Behalf Of Zehler,
Peter
Sent: Thursday, July 22, 2010 11:48
To: ipp at pwg.org; mfd at pwg.org
Subject: [IPP] Attributes needed for Cloud Printing and
definitioninconsistencies

 

Job Identifiers:

*existing*

job-id (SM: JobId): The identifier for a job with a local scope.  That is
the ID is unique within the service.  The ID may be reused in other instance
of a Printer (i.e. Print Service)  or for jobs in other types of services
(e.g. Copy Service).  Datatype: abstract:int32, IPP:integer, SM:xs:int

 

*new*

job-uuid (SM:JobUuid):  The identifier for a job with a global scope.  The
identifier is unique for a Job across all service instances of any service
type.    The UUID URN namespace is specified in rfc4122.  The format used
for "job-uuid" is the string representation of a UUID as a URN.  An example
is "urn:uuid:a6b90f34-d0b1-1956 -7dec-009c4386fe3".  The version (aka
subtype) used is implementation specific.  Version 1 (i.e. time based) is
recommended.   Datatype: abstract:char[64], IPP:uri MaxLength=64,
SM:xs:anyURI maxLen=64

 

Note:  I do not believe the IPP attribute "job-uri" is applicable as a
globally unique identifier.

1)      RFC2911 states "Since every URL is a specialized form of a URI, even
though the more generic term URI is used throughout the rest of this
document, its usage is intended to cover the more specific notion of URL as
well.".   All uses of the uri syntax is really a URL syntax.

2)      URL implies not only a specific protocol binding but also a
location.

3)      Locations can be specified using an IP address that need not be
locally unique (e.g. 192.168.1.1, localhost) 

4)      Regarding the "job-uri" RFC2911  further states that "This URI is
then used by clients as the target for subsequent Job operations.".  The
globally unique identifier for a job should not specify a transport endpoint
for a specific protocol.   

5)      The globally unique identifier for a Job, Printer or Service should
be a URN.  It should be protocol independent so that a product that supports
multiple protocols should have the same identifiers regardless of the
protocol mapping.

6)      The  globally unique identifier for a Job, Printer or Service should
require no central authority to administrate them.  Generation of a unique
identifier should be simple from an administrative point of view and
preferably automated.

 

Note: Both the local and global identifiers should be mandated.  For legacy
protocol mappings (e.g. IPP 1.1, WS-Print, LPR) the local identifier MUST
still be maintained.  It is possible to use the time_low portion of the
Timestamp in the version 1 UUID as the local identifier.  The implementation
may then keep only the 128 bit local representation of the UUID and use it
to create the appropriate protocol values.

 

Printer Identifiers:

*existing (Service Monitoring MIB)*

applIndex (SM: <service>Id i.e. PrinterId): The service identifier with a
local scope.  That is the ID is unique across the service instances
collocated on a host.  Datatype: abstract:int32, MIB:integer, SM:xs:int

 

*new*

printer-uuid (SM:ServiceUuid):  The identifier for a Printer with a global
scope.  The identifier is unique across all service instances of any service
type.    The UUID URN namespace is specified in rfc4122.  The format used
for "job-uuid" is the string representation of a UUID as a URN.  An example
is "urn:uuid:a6b90f34-d0b1-1956 -7dec-009c4386fe3".  The version (aka
subtype) used is implementation specific.  Version 1 (i.e. time based) is
recommended.   Datatype: abstract:char[64], IPP:uri, SM:xs:anyURI maxLen=64

 

Note:  I do not believe the IPP attribute "printer-uri" is applicable as a
globally unique identifier.  

1)      RFC2911 states "Since every URL is a specialized form of a URI, even
though the more generic term URI is used throughout the rest of this
document, its usage is intended to cover the more specific notion of URL as
well.".   All uses of the uri syntax is really a URL syntax.

2)      URL implies not only a specific protocol binding but also a
location.

3)      Locations can be specified using an IP address that need not be
locally unique (e.g. 192.168.1.1, localhost) 

4)      The printer may have multiple "printer-uri" values as enumerated in
the "printer-uris-supported" attribute.  There should be only a single
identifier for a printer.

5)      The globally unique identifier for a Job, Printer or Service should
be a URN.  It should be protocol independent so that a product that supports
multiple protocols should have the same identifiers regardless of the
protocol mapping.

6)      The  globally unique identifier for a Job, Printer or Service should
require no central authority to administrate them.  Generation of a unique
identifier should be simple from an administrative point of view and
preferably automated.

 

 

Note: The local instance id in the MIB and SM are artifacts of the model's
data binding and are insufficient for use as an identifier.  IPP's
printer-uri, the URL for Web Service bindings (e.g. WS-Print) and the IP
address for legacy protocols such as LPR and Port 9100 are also
insufficient.  They need not be globally unique.  Nonroutable IP addresses
may be used.  

 

Printer Location:

*existing*

printer-location (SM: ServiceLocation): Identifies the location of the
device that this Printer represents.  (Example: Pete's Office)  This is
helpful for a human but is pretty much useless for geolocation since the
content is implementation specific.   Datatype: abstract:char[127],
IPP:string MaxLength=127, SM:xs:int

 

*new*

printer-geo-location (SM:ServiceGeoLocation):  This identifies the location
of the associated device using the World Geodetic System 1984(WGS84).  The
means for expressing the location information is the same as used in DNS
(rfc1876)  Datatype: abstract:class, IPP:collection, SM:sequence

 

*new*

size (SM:Size):  Diameter of the bounding sphere containing the device
expressed in centimeters.    Datatype: abstract: int32, IPP:integer,
SM:xs:int

 

*new*

horizontal-precision (SM: HorizontalPrecision):  The horizontal precision
expressed as the diameter of the "circle of error" (i.e. twice the +- error
value)  The units are centimeters.    Datatype: abstract: int32,
IPP:integer, SM:xs:int

 

*new*

vertical-precision (SM: VerticalPrecision):  The vertical precision
expressed as the diameter of the "circle of error" (i.e. twice the +- error
value)  The units are centimeters.    Datatype: abstract:integer, IPP:
int32, SM:xs:int

 

*new*

latitude (SM:Latitude):  The latitude of the center of the sphere described
by the size attribute.  Expressed in thousandths of a second of arc.  The
value 2147483648  (231) represents the equator.  Values above that are north
and below are south.   Datatype: abstract: int32, IPP:integer, SM:xs:int

 

*new*

longitude (SM:Latitude):  The longitude of the center of the sphere
described by the size attribute.  Expressed in thousandths of a second of
arc.  The value 2147483648  (231) represents the prime meridian.  Values
above that are east and below are south.  The value is rounded away from the
prime meridian   Datatype: abstract: int32, IPP:integer, SM:xs:int

 

*new*

altitude (SM:Altitude):  The altitude of the center of the sphere described
by the size attribute.  Expressed in centimeters from a base of 100,000m
below the reference spheroid used by GPS [WGS 84].  Altitude above (or
below) sea level may be used as an approximation of altitude relative to the
[WGS 84] spheroid, though due to the Earth's surface not being a perfect
spheroid, there will be differences.    Datatype: abstract: int32,
IPP:integer, SM:xs:int

 

Note:  There is disagreement on the semantics for all the attributes between
what is posted on <http://pwg-wiki.wikispaces.com/Geolocation>  and what I
have in the definition above.  I took the definition directly from rfc1876
(I think).  See included text from rfc1876 and the location example below.  

 

 

 

Peter Zehler

Xerox Research Center Webster
Email:  <mailto:Peter.Zehler at Xerox.com> Peter.Zehler at Xerox.com
Voice: (585) 265-8755
FAX: (585) 265-7441
US Mail: Peter Zehler
Xerox Corp.
800 Phillips Rd.
M/S 128-25E
Webster NY, 14580-9701 

 

 

>From rfc1876 section 2 <http://www.rfc-editor.org/rfc/rfc1876.txt> 

 

SIZE         The diameter of a sphere enclosing the described entity, in

             centimeters, expressed as a pair of four-bit unsigned

             integers, each ranging from zero to nine, with the most

             significant four bits representing the base and the second

             number representing the power of ten by which to multiply

             the base.  This allows sizes from 0e0 (<1cm) to 9e9

             (90,000km) to be expressed.  This representation was chosen

             such that the hexadecimal representation can be read by

             eye; 0x15 = 1e5.  Four-bit values greater than 9 are

             undefined, as are values with a base of zero and a non-zero

             exponent.

 

             Since 20000000m (represented by the value 0x29) is greater

             than the equatorial diameter of the WGS 84 ellipsoid

             (12756274m), it is therefore suitable for use as a

             "worldwide" size.

 

HORIZ PRE    The horizontal precision of the data, in centimeters,

             expressed using the same representation as SIZE.  This is

             the diameter of the horizontal "circle of error", rather

             than a "plus or minus" value.  (This was chosen to match
             the interpretation of SIZE; to get a "plus or minus" value,
             divide by 2.)
 
VERT PRE     The vertical precision of the data, in centimeters,
             expressed using the sane representation as for SIZE.  This
             is the total potential vertical error, rather than a "plus
             or minus" value.  (This was chosen to match the
             interpretation of SIZE; to get a "plus or minus" value,
             divide by 2.)  Note that if altitude above or below sea
             level is used as an approximation for altitude relative to
             the [WGS 84] ellipsoid, the precision value should be
             adjusted.
 
LATITUDE     The latitude of the center of the sphere described by the
             SIZE field, expressed as a 32-bit integer, most significant
             octet first (network standard byte order), in thousandths
             of a second of arc.  2^31 represents the equator; numbers
             above that are north latitude.
 
LONGITUDE    The longitude of the center of the sphere described by the
             SIZE field, expressed as a 32-bit integer, most significant
             octet first (network standard byte order), in thousandths
             of a second of arc, rounded away from the prime meridian.
             2^31 represents the prime meridian; numbers above that are
             east longitude.
 
ALTITUDE     The altitude of the center of the sphere described by the
             SIZE field, expressed as a 32-bit integer, most significant
             octet first (network standard byte order), in centimeters,
             from a base of 100,000m below the [WGS 84] reference
             spheroid used by GPS (semimajor axis a=6378137.0,
             reciprocal flattening rf=298.257223563).  Altitude above
             (or below) sea level may be used as an approximation of
             altitude relative to the the [WGS 84] spheroid, though due
             to the Earth's surface not being a perfect spheroid, there
             will be differences.  (For example, the geoid (which sea
             level approximates) for the continental US ranges from 10
             meters to 50 meters below the [WGS 84] spheroid.
             Adjustments to ALTITUDE and/or VERT PRE will be necessary
             in most cases.  The Defense Mapping Agency publishes geoid
             height values relative to the [WGS 84] ellipsoid.
 

 

 

 

 

 

 

2-Dimmensional Location of my office printer

Google Map URL:

http://maps.google.com/maps?f=q
<http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=800+phillips+rd
+webster+ny+14580&sll=37.0625,-95.677068&sspn=62.226996,106.962891&ie=UTF8&h
q=&hnear=800+Phillips+Rd,+Webster,+Monroe,+New+York+14580&ll=43.220973,-77.4
17162&spn=0.001781,0.003264&t=h&z=19>
&source=s_q&hl=en&geocode=&q=800+phillips+rd+webster+ny+14580&sll=37.0625,-9
5.677068&sspn=62.226996,106.962891&ie=UTF8&hq=&hnear=800+Phillips+Rd,+Webste
r,+Monroe,+New+York+14580&ll=43.220973,-77.417162&spn=0.001781,0.003264&t=h&
z=19 

Location representations:

Decimal Degrees (WGS84)

Latitude Longitude 
43.220973 -77.417162 

Degrees, Minutes & Seconds

Latitude Longitude 
N43 13 15 W77 25 01 

GPS

Latitude Longitude 
N 43 13.258 W 77 25.030 

UTM

 X Y 

18N 303685 4788191 

 

My office elevation:

12800 centimeters (419 feet) above sea level

Size of Printer:

91 centimeter (3 feet)

Margin of error

183 centimeter (6 feet)

 

PrinterGeoLocation (RFC1876)

Size = 258 (0x0102) (encoded centimeter)
HorizontalPrecision = 514 (0x0202)  (encoded centimeter)
VerticalPrecision = 514 (0x0202)  (encoded centimeter)

Latitude = 2303079151 (thousandths of a second of arc, 231 represent
equater)  ( (DecimalDegreeLatitude*60*60*1000)+2147483648 )

Longitude = 1868781865 (thousandths of a second of arc, 231 represent prime
meridian) ( 2147483648-(DecimalDegreeLongitude*60*60*1000) )
Altitude = 10012800 (centimeter)  (OfficeElevation+10000000)

 

 


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