Selected Definitions of Managed Objects for
Public Transportation Vehicles (PTV)
Transit Communications Interface Protocols (TCIP)
White Paper 3
Prepared by
Xudong Jia
Paula Okunieff
Tom Buffkin
Karen Levine
Cambridge Systematics, Inc.
150 CambridgePark Drive, Suite 4000
Cambridge MA 02140
February 20, 1997
Preface
As part of soliciting input from the transit industry and the public, the Transit Communications Interface Protocols (TCIP) technical team is issuing a series of White Papers which
present assumptions, directions and methods we intend to use in the development of the
TCIP family of specifications.
This is the third paper in a series related to the family of specifications. In particular, the
purpose of this paper is to present an implementation of an object set whose format is
based on the NTCIP application structure (ASN.1) and the SAE J1708/J1587 message and
parameter identifiers (MID, PID). This object set describes the Automatic Vehicle
Location (AVL) subset of public transportation vehicle data. The last section deals with
conformance requirements for which we designated mandatory those parameters identified by SAE J1587. We welcome your comments on the paper, particularly, on requirements imposed on developers and product vendors.
The White Papers Series and related comments will be posted on the TCIP web site:
www.tcip.org. We invite interested parties to submit papers on issues concerning any
aspect of TCIP. Papers are subject to review by the TCIP Steering and Technical Advisory
Committees.
1.0 General
 1.1 Scope
The communications between components within a public transportation vehicle, transit
management centers, and other transit facilities are critical to public transportation
operations supported by a TCIP network. They are accomplished by using the TCIP
application layer services to exchange messages between PTV components resident in
heavy-duty vehicles and other transit facilities.
 1.2 References
There are a number of standards used to generate parts of this standard. These standards
are listed below.
[1]
SAE J1708 Serial Data Communications Between Microcomputer Systems in HeavyDuty vehicle applications, October 1990.
[2]
SAE J1587 Joint SAE/TMC Recommended Practice for Electronic Data Interchange
Between Microcomputer Systems in Heavy Duty Vehicle Applications, August
1992.
[3]
National Electrical Manufacturers Association, Draft Standard, National Transportation Control/ITS Communications Protocol (NTCIP),” September 12, 1995.
[4]
NEMA Standard Publication TS 3.1, NTCIP Overview, NEMA, March 1996.
As all standards are subject to revision, the latest issues of the above standards shall
apply.
Note: All references in the following sections are extracted from reference [2] (page
numbers are not included).
2.0 TCIP PTV-Object Definitions
This section defines those objects that are expected to be used in public transportation
vehicles (PTV). The OBJECT-TYPE macro defined in RFC 1212 is used to specify TCIP
PTV objects. The text provided from Clause 2.1 through the end of the section (except
clause headings) constitutes the TCIP standard for public transportation vehicles.
-3-
A family of TCIP standards will be adopted as portions of the NEMA standards.
In doing so, the subtrees under the transportation node should be reorganized as
shown below (subject to approval by the NTCIP steering committee). All the TCIP
standards are described under the TCIP node.
Transportation {1.3.6.1.4.1.1206}
NTCIP {1}
TCIP {2}
For the purpose of this section, the following OBJECT IDENTIFIERS are used:
nema OBJECT IDENTIFER::= {iso (1) org (3) dod (6) internet (1) private (4) enterprises
(1) 1206}
transportation OBJECT IDENTIFIER::= {nema 4}
tcip OBJECT IDENTIFER::= {transportation 2}
ptv OBJECT IDENTIFIER::= {tcip 1}
 2.1 Automatic Vehicle Location (AVL) Objects
ptvAVL
OBJECT-IDENTIFIER ::= {ptv 1}
--- The ptvAVL node contains objects that are used to provide current Automatic Vehicle
--- Location (AVL) data for various transit use.
2.1.1 Compass Bearing Parameter
ptvAVLCompassBearing
OBJECT-TYPE
SYNTAX
INTEGER(0 ... 65,535) UShort
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This object contains present compass bearing of a vehicle. The bit
resolution is 0.01. The value of the object ranges from 0.00 to 655.35
degree.”
::= { ptvAVL 1}
-4-
2.1.2 Current Time
[note: this definition is not consistent with NTCIP Current Time]
ptvAVLCurrentTime
OBJECT-IDENTIFIER ::= {ptvAVL 2}
--- This node indicates three objects are used to represent current time of an AVL device
--- in a public transportation vehicle.
ptvAVLCurrentSecond
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255) UByte
ACCESS
read-write
STATUS
mandatory
DESCRIPTION
Second of minute (defined in ptvAVLCurrentMinute) object that an
associated AVL device should experience. Maximum range of values
for this object is 0-255. It represents 0-63.75 s since the bit resolution is
0.25 s/bit. Valid range is 0-236 which represents 0-59 since there are
only 0-59 seconds in a minute”
::= {ptvAVLCurrentTime 1}
ptvAVLCurrentMinute
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255) UByte
ACCESS
read-write
STATUS
mandatory
DESCRIPTION
揗 inute of hour (defined in ptvAVLCurrentHour) object that an
associated AVL device should experience. Maximum range of values
for this object is 0-255. However, valid range is 0-59 since the bit
resolution is 1 min/bit and there are only 0-59 minutes in a hour.”
::= {ptvAVLCurrentTime 2}
ptvAVLCurrentHour
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255) UByte
ACCESS
read-write
STATUS
mandatory
DESCRIPTION
揌 our of day that an associated AVL device should experience
currently. Maximum range of values for this object is 0-255m.
However, valid range is 0-24 since the bit resolution is 1h/bit and
there are 0-24 hours in a day.”
::= {ptvAVLCurrentTime 3}
2.1.3 Current Date
ptvAVLCurrentDate
OBJECT-IDENTIFIER ::= {ptvAVL 3}
--- This defines a list of objects that specifies current date for an AVL device in a PTV.
ptvAVLCurrentDay
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255) UByte
ACCESS
read-write
STATUS
mandatory
-5-
DESCRIPTION
揇ay of the month (defined in ptvAVLCurrentMonth) object that an
associated AVL device should experience. Maximum range of values
for this object is 0-255. It represents 0-63.75 day since the bit resolution
is 0.25 day/bit. Valid range is 1-127 which represents 0.25-31.75 day
because there are only 1-30 days in a month. In detail, the values of
the object are defined as:
Value
Day of Month
0
1,2,3, and 4
5,6,7, and 8
!!
121, 122, 123, and 124
125,126, and 127
::= {ptvAVL
Null (Not Used)
Day 1
Day 2
Day 31
Not Used.”
CurrentDate 1}
ptvAVLCurrentMonth
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255) UByte
ACCESS
read-write
STATUS
mandatory
DESCRIPTION
揗 onth of the year (defined in ptvAVLCurrentYear) object that an
associated AVL device should experience. Maximum range of values
for this object is 0-255, however valid range is 1-12 since the bit
resolution is 1 month/bit and there are only 1-12 months in a year. In
detail, the values of the object are defined as:
Value
Month of Year
0
1
2
3
4
5
6
7
8
9
10
11
12
13-255
Null (Not Used)
January
February
March
April
May
June
July
August
September
October
November
December
Not Used.”
::= {ptvAVLCurrentDate 2}
-6-
ptvAVLCurrentYear
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255) UByte
ACCESS
read-write
STATUS
mandatory
DESCRIPTION
揧ear which an associated AVL device should experience currently.
The values for this object are 0-255. They represents the following
years:
Value
Year
0
1
!!
255
1985
1986
2240.”
::= {ptvAVLCurrentDate 3}
2.1.4 Trip Distance
ptvAVLTripDistance
OBJECT-TYPE
SYNTAX
INTEGER(0 ... 4,294,967,295) ULong
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
揟his object contains distance traveled during all or part of a journey.
The values of the object represent 0.0 to 691,207,984.6 km (0.0 to
429,496,729.5 mi) since the bit resolution is 0.16 km (0.1 mi).”
::= { ptvAVL 4}
2.1.5 Position
ptvAVLPosition
OBJECT-IDENTIFIER ::= {ptvAVL 5}
--- This node defines a list of objects that specifies current position of a vehicle in terms of
--- longitude, latitude, and altitude.
ptvAVLLatitude
OBJECT-TYPE
SYNTAX
INTEGER (-2,147,483,647 ... 2,147,483,647)Long
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This object contains location value of latitude of vehicle. Bit resolution
is 10-6 degree/bit.
Maximum range is from -2,147,483,647 to
+2,147,483,647 which represents the latitude value from -2,147.483648
to +2,147.483647. Positive value indicates NORTH, while negative
value indicates SOUTH.”
::= { ptvAVLPosition 1}
ptvAVLLongitude OBJECT-TYPE
SYNTAX
INTEGER (-2,147,483,647 ... 2,147,483,647)Long
ACCESS
read-only
STATUS
mandatory
-7-
DESCRIPTION
This object contains location value of longitude of vehicle. Bit
resolution is 10-6 degree/bit. Maximum range is from -2,147,483,647
to +2,147,483,647 which represents the longitude value
from -2,147.483648 to +2,147.483647. Positive value indicates EAST,
while negative value indicates WEST.”
::= { ptvAVLPosition 2}
ptvAVLAltitude
SYNTAX
ACCESS
STATUS
DESCRIPTION
OBJECT-TYPE
INTEGER (-32,767 ... 32,767) Short
read-only
mandatory
This object contains location value of altitude of vehicle. Bit resolution
is 0.15 m/bit (0.5 ft/bit). Maximum range is from -32,767 to +32,767
which represents the altitude value from -2,497 to +4,993.7 m
(from -16,384 to 16,383.5 ft). The altitude value is referenced to sea
level at standard atmospheric pressure and temperature.”
::= { ptvAVLPosition 3}
2.1.6 Velocity Vector
ptvAVLVelocityVector
OBJECT-IDENTIFER ::= {ptvAVL 6}
--- This node defines a list of objects that specifies current velocity, heading, and pitch of
--- vehicle.
ptvAVLVelocity
SYNTAX
ACCESS
STATUS
DESCRIPTION
OBJECT-TYPE
INTEGER (0 ... 255)UByte
read-only
mandatory
揟his object contains current calculated vehicle speed. Bit resolution is
0.805 km/h (0.5 mph). Maximum range is from -36.2 to +90.6 km/h
(-45 to +112.5 mph). The range is offset to acknowledge backward
motion. Value of 91 km/h (113 mph) indicates 揇ate Not Available”).”
::= { ptvAVLVelocityVector 1}
ptvAVLHeading
SYNTAX
ACCESS
STATUS
DESCRIPTION
OBJECT-TYPE
INTEGER (0 ... 65,534)UShort
read-only
mandatory
This object contains current heading of vehicle. Bit resolution is 0.01
degree/bit. Maximum range is 0-65,534 (0-655.34 degree). Degree of
655.35 indicates Data not Available.”
::= { ptvAVLVelocityVector 2}
ptvAVLPitch
SYNTAX
ACCESS
STATUS
DESCRIPTION
OBJECT-TYPE
INTEGER (-32,767 ... 32,767) Short
read-only
mandatory
This object contains current pitch of vehicle. Bit resolution is 0.01
degree/bit. Maximum range is from -32,767 to +32,767 which
-8-
represents the pitch value from -327.67 to +327.67 degree. The value
of -327.68 indicates Data Not Available.” Positive pitch value indicates
ASCENT, while negative value indicates DESCENT.”
::= { ptvAVLVelocityVector 3}
2.1.7 Acceleration
ptvAVLAccel
SYNTAX
ACCESS
STATUS
DESCRIPTION
::= { ptvAVL 7}
OBJECT-TYPE
INTEGER (-32,767 ... 32,767) Short
read-only
mandatory
This object contains scalar acceleration of vehicle. Bit resolution is
0.322 (km/h)/s (0.2 mph/s). Maximum range is from -32,767 to 32,767
(-41.216 to 40.894 (km/h)/s or -25.6 to 25.4 mph/s). Negative value
indicates deceleration.”
2.1.8 Total Vehicle Distance
ptvAVLTotalVehicleDistance
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 4,294,967,295)ULong
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This object contains accumulated distance traveled by vehicle during
its operation. Bit resolution is 0.161 (km/h)/s (0.1 mph/s). Maximum
range is from 0.0 to 691,207,984.6 km (0.0 to 429,496,729.5 mi).”
::= { ptvAVL 8}
2.1.9 Milepost Identification
ptvAVLMilePostIdentification
OBJECT-TYPE
SYNTAX
OCTET STRING
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This object contains information used to identify the milepost as
detected by a milepost sensor. Currently this object needs further
information regarding the size the octet string shall have.”
::= { ptvAVL 9}
2.1.10 Annunciator Voice Message
ptvAVLAnnunciator
OBJECT-IDENTIFER ::= {ptvAVL 10}
--- This node defines a list of objects that are used to identify the message to be announced
--- by annuciator(s).
-9-
ptvAVLAnnunciatorParameters OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255)UByte
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This object contains information of annunciator location and volume
level. Bit resolution is binary. Maximum range is 0-255. The
annunciator location and volume level are defined as follows:
Bit 8:
Front, Interior
1 = generate message
0 = do not generate message
Bit 7:
Middle, Interior
1 = generate message
0 = do not generate message
Bit 6:
Rear, Interior
1 = generate message
0 = do not generate message
Bit 5:
Front, External
1 = generate message
0 = do not generate message
Bit 4-1: Volume level
where 0 = minimum level available
and 15 = maximum level available.”
::= { ptvAVLAnnunciator 1}
ptvAVLAnnunciatorMessage OBJECT-TYPE
SYNTAX
INTEGER (0 ... 65,534)UShort
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
揟his object contains up to 65,536 preset messages generated by an
annunciator. Bit resolution is binary. Maximum range is 0-65,534.”
::= { ptvAVLAnnunciator 2}
2.1.11 Reporting Interval Request
ptvAVLIntervalRequest OBJECT-IDENTIFER ::= {ptvAVL 11}
--- This node defines a list of objects that are used to request a device to change the
--- specified transmission update period to a new interval.
ptvAVLRequestMID
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255)UByte
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
揟his object contains message ID (or device ID) of destination device.
Bit resolution is binary. Maximum range is 0-255.”
::= { ptvAVLIntervalRequest 1}
- 10 -
ptvAVLRequestPID
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255)UByte
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This object contains parameter ID (object ID or ID of a group of objects)
associated with the destination device defined by message ID in
ptvAVLRequestMID. Bit resolution is binary. Maximum range is 0255 which represents parameter ID from 256-511.”
::= { ptvAVLIntervalRequest 2}
ptvAVLRequestIntervalTime
OBJECT-TYPE
SYNTAX
INTEGER (0 ... 255)UByte
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This object contains desired transmission update period for the
object(s) defined in the parameter ID (in ptvAVLRequestPID). Bit
resolution is 1s/bit. Maximum range is 0-255 which represents the
update period from 0-255s.
For example, this object may be used to change the transit door status
reporting from 揳s needed” to “1 second” in an emergency situation.”
::= { ptvAVLIntervalRequest 3}
3.0 CONFORMANCE GROUP DEFINITIONS
A conformance group is defined as a basic unit of conformance (see TS 3.2爾 1996 Simple
Transportation Management Network (STMP) Section 3.3.5). It is used to specify a collection of ptv-related objects that are required to support a function in a component of a
public transportation vehicle.
The conformance group definitions for specific device-types of AVL, including dead reckoning-based, milepost-based, triangulation-based, and GPS-based AVLs are defined in
this section.
 3.1 Dead Reckoning Conformance Group
The Dead Reckoning Conformance group, which is used for Dead Reckoning-based AVL
devices (or components), consists of a variety of AVL-related objects. The conformance
group shall be mandatory and shall consist of the following objects:
- 11 -
Object Name
Reference
ptvAVLLatitude
ptvAVLLongitude
ptvAVLAltitude
ptvAVLVelocity
ptvAVLHeading
ptvAVLPitch
ptvAVLAccel
ptvAVLCompassBearing
ptvAVLTripDistance
ptvAVLTotalVehicleDistance
ptvAVLAnnunciator
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
 3.2 Milepost Conformance Group
The milepost Conformance group, which is used for Milepost-based AVL devices (or
components), consists of a variety of AVL-related objects. The conformance group shall
be mandatory and shall consist of the following objects:
Object Name
Reference
ptvAVLMilePostIdentifiation
ptvAVLLatitude
ptvAVLLongitude
ptvAVLAltitude
ptvAVLAnnunciator
ptvAVLRequestMID
ptvAVLRequestPID
ptvAVLRequestIntervalTime
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
 3.3 Triangulation Conformance Group
The triangulation Conformance group, which is used for triangulation-based AVL devices
(or components), consists of a variety of AVL-related objects. The conformance group
shall be mandatory and shall consist of the following objects:
Object Name
Reference
ptvAVLLatitude
ptvAVLLongitude
ptvAVLAltitude
ptvAVLVelocity
ptvAVLHeading
ptvAVLPitch
ptvAVLAccel
ptvAVLCompassBearing
ptvAVLCurrentSecond
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
- 12 -
ptvAVLCurrentMinute
ptvAVLCurrentHour
ptvAVLCurrentDay
ptvAVLCurrentMonth
ptvAVLCurrentYear
ptvAVLTripDistance
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
The object called ptvAVLAnnunciator in Section 2 is optional depending on whether the
navigation device is capable of triggering an annunciator message from the current location. If it can, the object should be included in the conformance group.
 3.4 Global Positioning System (GPS) Conformance Group
The GPS Conformance group, which is used for GPS-based AVL devices (or components),
consists of a variety of AVL-related objects. The conformance group shall be mandatory
and shall consist of the following objects:
Object Name
Reference
ptvAVLLatitude
ptvAVLLongitude
ptvAVLAltitude
ptvAVLVelocity
ptvAVLHeading
ptvAVLPitch
ptvAVLAccel
ptvAVLCompassBearing
ptvAVLCurrentSecond
ptvAVLCurrentMinute
ptvAVLCurrentHour
ptvAVLCurrentDay
ptvAVLCurrentMonth
ptvAVLCurrentYear
ptvAVLTripDistance
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
Section 2
The object called ptvAVLAnnunciator in Section 2 is optional depending on whether the
navigation device is capable of triggering annunciator a message from the current location. If it can, the object should be included in the conformance group.
- 13 -