1、DRAFT FOR DEVELOPMENT DD ENV 12315-2:1997 Traffic and Traveller Information (TTI) TTI Messages via Dedicated Short-Range Communication Part 1: Data Specification Uplink (Vehicle to Roadside) ICS 35.240.60DDENV12315-2:1997 This Draft for Development, having been prepared under thedirection of the Ele
2、ctrotechnical Sector Board, waspublished underthe authorityof the Standards Boardand comes into effect on 15 April 1997 BSI 03-1999 The following BSI references relate to the work on this publication: Committee reference EPL/278 ISBN 0 580 27320 2 Committees responsible for this Draft for Developmen
3、t The preparation of this Draft for Development was entrusted to Technical Committee EPL/278, Road transport informatics, upon which the following bodies were represented: Automatic Identification Manufacturers Association (AIM UK) British Telecommunications plc Consumer Policy Committee of BSI Depa
4、rtment of Transport GAMBICA (BEAMA Ltd.) Road Signalling Development Association Society of Motor Manufacturers and Traders Limited Amendments issued since publication Amd. No. Date CommentsDDENV12315-2:1997 BSI 04-1999 i Contents Page Committees responsible Inside front cover National foreword ii F
5、oreword 2 Text of ENV 12315-2 3DDENV12315-2:1997 ii BSI 04-1999 National foreword This Part of DDENV 12315 has been prepared by Technical Committee EPL/278, and is the English language version of ENV12315-2:1996, published by the European Committee for Standardization (CEN). This Draft for Developme
6、nt is not to be reguarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature because the level of innovation on this subject is currently high. It should be applied on this provisional basis so that information and experience
7、of its practical application may be obtained. Comments arising from the use of this Draft for Development are requested so that the UK experience can be reported to the European organization responsible for its conversion to a European Standard. A review of this publication will be initiated 2 years
8、 after its publication by the European organization so that a decision can be taken on its status at the end of its three-year life. The commencement of the review period will be notified by an announcement in BSI Update. According to the replies received by the end of the review period, the respons
9、ible BSI Committee will decide whether to support the conversion into a European Standard, to extend the life of the prestandard or to withdraw it. Comments should be sent in writing to the Secretary of BSI Technical Committee EPL/278 at BSI, 389 Chiswick High Road, London, W4 4AL, giving the docume
10、nt reference and clause number and proposing, where possible, an appropriate revision of the text. Cross-references Publication referred to Corresponding British Standard ISO 8824 BS ISO/IEC 8824:1990 Information technology. Open systems interconnection. Specification of abstract syntax notation one
11、 (ASN.1) ISO 8825 BS ISO/IEC 8825:1990 Information technology. Open systems interconnection. Specification of basic encoding rules for abstract syntax notation one (ASN.1) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the ENV title page, pages 2 to 26
12、 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.EUROPEAN PRESTANDARD PRNORME EUROPENNE EUROPISCHE VORNORM ENV 12315-2 August 1996 ICS 35.240.60 Descriptors: Telepro
13、cessing, road transport, traffic, traffic control, information interchange, radiocommunications, open systems interconnection, data transmission, messages, data, specifications English version Traffic and Traveller Information (TTI) TTI Messages via Dedicated Short-Range Communication Part 2: Data S
14、pecification Uplink (Vehicle to Roadside) This European Prestandard (ENV) was approved by CEN on 1996-07-24 as a prospective standard for provisional application. The period of validity of this ENV is Limited initially to three years. After two years the members of CEN will be requested to submit th
15、eir comments, particularly on the question whether the ENV can be converted into an European Standard (EN). CEN members are required to announce the existance of this ENV in the same way as for an EN and to make the ENV available promptly at national level in an appropriate form. It is permissible t
16、o keep conflicting national standards in force (in parallel to the ENV) until the final decision about the possible conversion of the ENV into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxe
17、mbourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 Copyright reserved to CEN members Ref. No. ENV
18、12315-2:1996 EENV12315-2:1996 BSI 04-1999 2 Foreword (Informative) This Prestandard has been prepared by Working Group 4 (Sub-Working Group 4.2) of Technical Committee CEN/TC278 “Road transport and traffic telematics”, the secretariat of which is held by NNI to cover the Work Item 4.2.2. In the fiel
19、d of Traffic and Traveller Information, the innovative rate is high, with many research and development projects under way in many countries, and there is a need to establish prospective standards which allow competitive manufacturers to introduce products to the market in the knowledge that they ca
20、n accommodate the future issues of the standard(s) without fundamental change to equipment. It has been submitted as a first draft to TC278 for consideration and review by TC278 plenary meeting members, for initial comment, as CEN Stage 32. All comments have been reviewed and the document updated. I
21、t is hereby issued to CEN Central Secretariat for distribution in accordance with Internal Regulations (Part 2, Section 7) at CEN Stage 49, for formal voting. No known national standards (identical or conflicting) exist on this subject. This document constitutes: Part 1 of a two-part European Presta
22、ndard, being the data specification for one way (roadside to vehicle direction) of a two-way communications link. Part 2 of this Prestandard covers the reverse direction (vehicle to roadside). According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following co
23、untries are bound to announce this European Prestandard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents (Informative) Page Foreword (Informative) 2 Introducti
24、on (Informative) 3 1 Scope (Normative) 3 1.1 General 3 1.2 Embeddance in ISO-Layer model 3 2 Normative References (Normative) 3 3 Definitions (Normative) 4 3.1 Definitions 4 3.2 Symbols and Abbreviations 6 4 General Structure: Uplink Data Set (Normative) 6 4.1 Overall Structure 6 4.2 Format of the T
25、elegram 7 4.3 Contents of the Telegram 7 4.4 Autonomous Parts during a Journey 9 4.5 A Telegram cannot be sent 9 5 Data Organization Stucture (Telegram Format) (Normative) 10 6 General Data Table (ID 0) (Normative) 10 6.1 General 10 6.2 Data Coding 10 7 Route Description Table (ID 1) (Normative) 13
26、7.1 General 13 7.2 Data Coding 14 8 Measurements Table (ID 2) (Normative) 15 8.1 General 15 8.2 Data Coding 17 9 Maintenance Table (ID 3) (Normative) 19 9.1 General 19 9.2 Data Coding 20 10 Evaluation Table (ID 4) (Normative) 20 10.1 General 20 10.2 Data Coding 21 11 Checksum Table (ID 63) (Normativ
27、e) 22 11.1 General 22 11.2 Data Coding 22 11.3 Checksum Algorithm 22 Annex A Limitations (Normative) 24 Annex B Fixed Codings (Normative) 25 Annex C Summary of Tables (Normative) 26ENV12315-2:1996 BSI 04-1999 3 Introduction (INFORMATIVE) Traffic and Traveller Information may be disseminated through
28、a number of services or means of communication, covering static displays, interactive terminals and in-vehicle equipment. For all such services, the data to be disseminated and the message structures involved in the various interfaces require clear definition and standard formats, in order to allow
29、competitive products to operate with any received data. This pre-Standard focuses on the data specification for an air-interface via dedicated short-range communication, whereby information is produced at a central location (known as the in-station, central office or traffic information and control
30、centre) and disseminated via a network of roadside beacons (Part 1 of this pre-Standard) and information/data is transferred from in-vehicle units, via roadside beacons, to a central location (Part 2 of this pre-Standard). It enables messages to be exchanged between different systems and service pro
31、viders adopting a variety of applications specifications. Other pre-Standards are being produced by the CEN TC278 Working Group 4, to cover TTI dissemination via other means or services. It is anticipated that the uses of the data set(s) described in this document will be closely linked to the wides
32、pread use of in-vehicle equipment which utilises them known as “beacon data” in an efficient manner to guide drivers through the mad network accurately and safely. The principle of operation is to follow detailed guidance, step by step, from one beacon to another. The in-vehicle equipment is expecte
33、d to offer “fall-back” fascilities to assist the driver whenever he or she is travelling in an area unequipped with beacons or if the beacon data is unavailable, for whatever reason. 1 Scope (NORMATIVE) 1.1 GENERAL A Centrally Determined Route Guidance (CDRG) system using Dedicated Short Range Commu
34、nication (DSRC) is based on infrastructure and equipped vehicles. The Route Guidance Information (RGI) is generated by a Central Office (CO) and distributed via DSRC to the equipped vehicles. To enable dynamic RGI the Central Office needs real time traffic flow data. This data is provided through th
35、e system itself using vehicles as probes. This document is intended to specify the data telegram containing the measurement values transmitted from the vehicles to the beacons. The data described here corresponds to the downlink specification, application RGI. 1.2 EMBEDDANCE IN ISO-LAYER MODEL Figur
36、e 1 shows the inclusion of this standard with the seperate communication means supplementing the deliverables of other WGs, where the protocols and communications “data frame” structures are defined. For transmitting the telegrams the transportation services defined by WG 9 (Dedicated Short Range Co
37、mmunication) are used, which ensure the application handling. 2 Normative References (NORMATIVE) This document complements the “Data Specification RGI Downlink (Beacon to Vehicle)” specification prENV278/4/2/0016-1. Additional references: ISO/IEC 8824 Specification of Abstract Syntax Notation One (A
38、SN.1) ISO/IEC 8825 Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1) ISO/IEC DIS 8825-2 Information technology Open Systems Interconnection Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1) Part 2: Packed Encoding Rules prENV (WI: 00278051) D
39、SRC Application layer (OSI-Layer 7) prENV 278/9/#61 DSRC Communication ArchitectureENV12315-2:1996 4 BSI 04-1999 3 Definitions (NORMATIVE) 3.1 DEFINITIONS For the purpose of this standard, the following definitions apply: Figure 1 Dedicated Short Range Communication according to ISO-Layer model beac
40、on A roadside facility which is capable to communicate: Via “air interface” in a limited communication zone with IVU of passing vehicles. Via fixed network with centrally or decentrally located control units like central route guidance computer (optional). A beacon consists of a beacon controller an
41、d one or more connected beacon heads as transceivers for the air interface beacon exit This is the physical exit which a vehicle takes from a beacon equipped junction. It is important to be able to unambiguously identify the correct exit taken by a vehicle from a beacon site because, the route guida
42、nce information is referenced to this. beacon site A beacon installation location. There are several possible locations for beacon installation: beside the road left and/or right hand, above the road on gantries at intersections on entry and/or exit. central office The central computer centre respon
43、sible for origination and generation of transmitted information. dead reckoning Calculating a vehicles position by keeping track of the distances and directions travelled from a known starting point. departure point Is the point on the link chain near to the destination at which guidance is switched
44、 back to autonomous mode in vehicle system to direct drivers to their destination. destination region The destination coordinate used for the actual journey with a resolution decreased to about 100m. It is used for getting the origin-destination-relation.ENV12315-2:1996 BSI 04-1999 5 downlink Commun
45、ication directed from roadside to IVU. guidance information A guidance information is a chain of “links”, a vehicle has to follow from its actual position to the next beacon or directly to its destination zone, if nearer than neighbouring beacons. Both the sequence of those links and their exact geo
46、metrical representation are described here, together with attributes, to be displayed to the driver. journey A journey starts with choosing a new destination by the driver and ends with the beginning of the next journey. It is independent of the particular IVU mode (guided orautonomous). link A link
47、 is a road section between two junctions. The link is the smallest individual addressable network element. Unidirectional connection between two nodes, mostly representing a connection between two intersections, in traffic assignment one intersection can be dissolved into several turning links or on
48、e link can comprise a sequence of connections between intersections. link chain Complete chain of links describing the route to the next beacon or to an departure point for the destination area. maintenance data Data used to maintain the IVU. mapping information Is the information transmitted by the
49、 beacon which describes the network in the beacon region and allows the vehicle to track its position as it moves in the network. measurement point Several traffic measurements (such as queueing time, number of stops etc) are assigned to a measurement point. These measurements are taken between the last and the actual measurement point. At least a measurement point is defined at the end of each link by default, but it is possible to define additional measurement points at the end of the vectors the link is build with. modal cha
