Commission Implementing Regulation (EU) 2016/799Show full title

5. REMOTE COMMUNICATION DESIGN AND PROTOCOLS

5.1 Design

The design of the remote communication function in the Smart Tachograph is shown as described in Figure 14.3.

Figure 14.3

Design of the remote communication function

DSC_19 The following functions are located in the VU:

• Security Module (VUSM). This function present in the VU is responsible for securing the Data which is to be transmitted from the DSRC-VU to the agent of the competent control authorities via remote communication.

• The secured data is stored in the VUSM memory. At intervals determined in 4.1.1.1 (DSC_12), the VU encrypts and replenishes the RTMdata concept (which comprises payload data and security data concept values determined below in this Appendix) held in the memory of the DSRC-VU. The operation of the security module is defined in Appendix 11 Common Security Mechanisms and outwith the scope of this Appendix, save that it shall be required to provide updates to the VU Communication facility each time the VUSM data changes.

• The communication between the VU and the DSRC-VU may be a wired communication or a Bluetooth Low Energy (BLE) communication, and the physical location of the DSRC-VU may be integral with the antenna on the windshield of the vehicle, may be internal to the VU, or located somewhere between.

• The DSRC-VU shall have a reliable source of power available at all times. The means by which it is provided with its power is a design decision.

• The memory of the DSRC-VU shall be non-volatile in order to maintain the Data in the DSRC-VU even when the vehicle ignition is switched off.

• If the communication between the VU and the DSRC-VU is made via BLE and the power source is a non-recharging battery, the power source of the DSRC-VU shall be replaced at every Periodic Inspection, and the manufacturer of the DSRC-VU equipment shall be responsible to ensure that the power supply is adequate to last from one Periodic Inspection to the next Periodic Inspection, maintaining normal access to the data by an REDCR throughout the period without failure or interruption.

• VU RTM ‘payload memory’ facility (VUPM). This function present in the VU is responsible for providing and updating the Data. The content of The Data. (‘TachographPayload’) is defined in 5.4.4/5.4.5 below and is updated at the interval determined in 4.1.1.1 (DSC_12).

• DSRC-VU. This is the function, within or connected to the antenna and in communication with the VU through a wired or wireless (BLE) connection, which holds the current data (VUPM-data) and manages the response to an interrogation across the 5.8 GHz DSRC medium. Disconnection of the DSRC facility or interference during normal vehicle operation with the functioning of the DSRC facility shall be construed as a violation of Regulation (EU) No 165/2014.

• Security module (REDCR) (SM-REDCR) is the function used to decrypt and check integrity of the data originating from the VU. The means by which this is achieved is determined in Appendix 11 Common Security Mechanisms, and is not defined in this Appendix.

• The DSRC facility (REDCR) (DSRC-REDCR) function comprises a 5.8 GHz transceiver and associated firmware and software which manages the Communication with the DSRC-VU according to this Appendix.

• The DSRC-REDCR interrogates the DSRC-VU of the targeted vehicle and obtains the Data (the targeted vehicle's current VUPM-data) via the DSRC link and processes and stores the received data in its SM-REDCR.

• The DSRC-VU antenna shall be positioned at a location where it optimizes the DSRC communication between the vehicle and the roadside antenna (in general in or close to the centre of the vehicle windshield …). For light vehicles an installation corresponding to the upper part of the windscreen is suitable.

  • There shall be no metal objects (e.g. name badges, stickers, foil anti reflection (tinting) strips, sun visors, windshield wiper at rest) in front of, or close to the antenna, that can interfere with the communication.

  • The antenna shall be mounted so that its boresight approximately is parallel with the surface of the road.

DSC_20 The Antenna and The Communication shall operate within ERC 70-03, tested against the appropriate parameters of EN 300 674-1 as described in section 5. The Antenna and the Communication can implement mitigation techniques against the risk of wireless interference as described in ECC report 228 using e.g., filters in the CEN DSRC 5.8 GHz communication.

DSC_21 The DSRC antenna shall be connected to the DSRC-VU facility either directly within the module mounted to or close to the windshield, or through a dedicated cable constructed in a manner to make illegal disconnection difficult. Disconnection of or interference with the functioning of Antenna shall be a violation of Regulation (EU) No 165/2014. Deliberate masking or otherwise detrimentally affecting the operational performance of the Antenna shall be construed as a violation of Regulation (EU) No 165/2014.

DSC_22 The form factor of the antenna is not defined and shall be a commercial decision, so long as the fitted DSRC-VU meets the conformance requirements defined in section 5 below. The antenna shall be positioned as determined in DSC_19 and shown in figure 14.4 (oval line) and it efficiently supports the use cases described in in 4.1.2 and 4.1.3.

Figure 14.4

Example of positioning of the 5,8 GHz DSRC antenna in the windshield of regulated vehicles

The form factor of the REDCR and its antenna may vary according to the circumstances of the reader (tripod mounted, hand held, vehicle mounted, etc.) and the modus operandi employed by the agent of the competent control authorities.

A display and/or notification function is used to present the results of the remote communication function to the agent of the competent control authorities. A display may be provided on a screen, as a printed output, an audio signal, or a combination of such notifications. The form of such display and/or notification is a matter of the requirements of the agents of the competent control authorities and equipment design and is not specified within this Appendix.

DSC_23 The design and form factor of the REDCR shall be a function of commercial design, operating within ERC 70-03, and the design and performance specifications defined in this Appendix, (section 5.3.2), thus providing the marketplace maximum flexibility to design and provide equipment to cover the specific interrogation scenarios of any particular competent control authority.

DSC_24 The design and form factor of the DSRC-VU and its positioning inside or outside the VU shall be a function of commercial design, operating within ERC 70-03 and the design and performance specifications defined in this Appendix (section 5.3.2) and within this Clause (5.1).

DSC_25 However, the DSRC-VU shall be reasonably capable to accept data concept values from other intelligent vehicle equipment by means of an open industry standard connection and protocols. (For example from weigh on board equipment), so long as such data concepts are identified by unique and known application identifiers/file names, and the instructions to operate such protocols shall be made available to the European Commission, and available without charge to manufacturers of relevant equipment.

5.2 Workflow

5.2.1 Operations

The workflow of operations is represented in Figure 14.5.

Figure 14.5

Workflow for remote communication function

The steps are described below:

a.

Whenever the vehicle is in operation (ignition ON) the tachograph is providing data to the VU function. The VU function prepares the Data for the remote communication function (encrypted) and updates the VUPM held in the memory of the DSRC-VU (as defined in 4.1.1.1 — 4.1.1.2). The Data collected shall be formatted as determined in 5.4.4 — 5.4.5 below.

b.

On every occasion that the Data is updated, the timestamp defined in the security data concept shall be updated.

c.

The VUSM function secures the data in accordance with the procedures determined in Appendix 11.

d.

On every occasion that the Data is updated (see 4.1.1.1 — 4.1.1.2), the Data shall be transferred to the DSRC-VU, where it replaces any previous data, in order that updated current data (the Data) shall always be available to be provided in the event of an interrogation by an REDCR. When supplied by the VU to the DSRC-VU the Data shall be identifiable by the filename RTMData or by ApplicationID and Attribute identifiers.

e.

If an agent of the competent control authorities wishes to target a vehicle and collect the Data from the targeted vehicle, the agent of the competent control authorities shall first insert his/her smartcard in the REDCR to enable the Communication and to allow the SM-REDCR to verify its authenticity and decrypt the data.

f.

The agent of the competent control authority then targets a vehicle and requests the data through remote communication. The REDCR opens a 5.8 GHz DSRC interface session with the DSRC-VU of the targeted vehicle, and requests the Data. The Data is transferred to the REDCR through the wireless communication system as a DSRC Attribute using the Application service GET as defined in 5.4. The Attribute contains the encrypted payload data values and the DSRC security data.

g.

The data is analyzed by the REDCR equipment and provided to the agent of the competent control authority.

h.

The agent of the competent control authority uses the data to assist in a decision of whether or not to stop for a detailed inspection, or ask another agent of the competent control authority to stop the vehicle.

5.2.2 Interpretation of the Data received via the DSRC communication

DSC_26 Data received across the 5.8 GHz interface shall carry the meaning and import defined in 5.4.4 and 5.4.5 below and only that meaning and import, and shall be understood within the objectives defined therein. In accordance with the provisions of Regulation (EU) No 165/2014, the Data shall be used only to provide relevant information to a competent control authority to assist them to determine which vehicle should be stopped for physical inspection, and shall be subsequently destroyed in accordance with Article 9 of Regulation (EU) No 165/2014.

5.3 DSRC Physical interface parameters for remote communication

5.3.1 Location constraints

DSC_27 The remote interrogation of vehicles using a 5.8GHz DSRC interface should not be used within 200 metres of an operational 5.8 GHz DSRC gantry.

5.3.2 Downlink and uplink parameters

DSC_28 The equipment used for remote tachograph monitoring shall conform to and operate within ERC70-03 and the parameters defined in Tables 14.1 and 14.2 below.

DSC_29 Further, to ensure compatibility with the operational parameters of other standardised 5.8 GHz DSRC systems, the equipment used for remote tachograph monitoring shall conform to parameters from EN 12253 and EN 13372.

Namely:

Table 14.1

Downlink parameters

a – Downlink parameters subject to conformance testing in accordance with relevant parameter test from EN 300 674-1.
Item No	Parameter	Value(s)	Remark
D1	Downlink Carrier Frequencies	There are four alternatives which may be used by an REDCR: 5,7975 GHz 5,8025 GHz 5,8075 GHz 5,8125 GHz	Within ERC 70-03. Carrier Frequencies may be selected by the implementer of the roadside system and need not be known in the DSRC-VU (Consistent with EN 12253, EN 13372)
D1a a	Tolerance of Carrier Frequencies	within ± 5 ppm	(Consistent with EN 12253)
D2 a	RSU (REDCR) Transmitter Spectrum Mask	Within ERC 70-03. REDCR shall be according to Class B,C as defined in EN 12253. No other specific requirement within this Annex	Parameter used for controlling interference between interrogators in proximity (as defined in EN 12253 and EN 13372).
D3	OBU(DSRC-VU) Minimum Frequency Range	5,795 — 5,815 GHz	(Consistent with EN 12253)
D4 a	Maximum E.I.R.P.	Within ERC 70-03 (unlicensed) and within National Regulation Maximum + 33 dBm	(Consistent with EN 12253)
D4a	Angular E.I.R.P. mask	According to declared and published specification of interrogator designer	(Consistent with EN 12253)
D5	Polarisation	Left hand circular	(Consistent with EN 12253)
D5a	Cross-Polarisation	XPD: In bore sight: (REDCR) RSU t ≥ 15 dB (DSRC-VU) OBU r ≥ 10 dB At -3 dB area: (REDCR) RSU t ≥ 10 dB (DSRC-VU) OBU r ≥ 6 dB	(Consistent with EN 12253)
D6 a	Modulation	Two level amplitude modulation.	(Consistent with EN 12253)
D6a a	Modulation Index	0,5 ... 0,9	(Consistent with EN 12253)
D6b	Eye Pattern	≥ 90 % (time) / ≥ 85 % (amplitude)
D7 a	Data Coding	FM0 ‘1’ bit has transitions only at the beginning and end of the bit interval. ‘0’ bit has an additional transition in the middle of the bit interval compared to the ‘1’ bit.	(Consistent with EN 12253)
D8 a	Bit rate	500 kBit/s	(Consistent with EN 12253)
D8a	Tolerance of Bit Clock	better than ± 100 ppm	(Consistent with EN 12253)
D9 a	Bit Error Rate (B.E.R.) for communication	≤ 10– 6 when incident power at OBU (DSRC-VU) is in the range given by [D11a to D11b].	(Consistent with EN 12253)
D10	Wake-up trigger for OBU (DSRC-VU)	OBU (DSRC-VU) shall wake up on receiving any frame with 11 or more octets (including preamble)	No special wake-up pattern is necessary. DSRC-VU may wake up on receiving a frame with less than 11 octets (Consistent with EN 12253)
D10a	Maximum Start Time	≤ 5 ms	(Consistent with EN 12253)
D11	Communication zone	Spatial region within which a B.E.R. according to D9a is achieved	(Consistent with EN 12253)
D11a a	Power Limit for communication (upper).	– 24dBm	(Consistent with EN 12253)
D11b a	Power Limit for communication (lower).	Incident power: – 43 dBm (boresight) – 41 dBm (within – 45° ± 45°Corresponding to the plane parallel to the road surface when the DSRC-VU later is installed in the vehicle (Azimuth))	(Consistent with EN 12253) Extended requirement for horizontal angles up to ±45°, due to the use cases defined in this annex.
D12 a	Cut-off power level of (DSRC-VU)	– 60 dBm	(Consistent with EN 12253)
D13	Preamble	Preamble is mandatory.	(Consistent with EN 12253)
D13a	Preamble Length and Pattern	16 bits ± 1 bit of FM0 coded ‘1’ bits	(Consistent with EN 12253)
D13b	Preamble Wave form	An alternating sequence of low level and high level with pulse duration of 2 μs. The tolerance is given byD8a	(Consistent with EN 12253)
D13c	Trailing Bits	The RSU (REDCR) is permitted to transmit a maximum of 8 bits after the end flag. An OBU (DSRC-VU) is not required to take these additional bits into account.	(Consistent with EN 12253)

Table 14.2

Uplink parameters

a – Uplink parameters subject to conformance testing in accordance with relevant parameter test from EN 300 674-1
Item No.	Parameter	Value(s)	Remark
U1 a	Sub-carrier Frequencies	A OBU (DSRC-VU) shall support 1,5 MHz and 2,0 MHz An RSU (REDCR) shall support 1,5 MHz or 2,0 MHz or both. U1-0: 1,5 MHz U1-1: 2,0 MHz	Selection of sub-carrier frequency (1,5 MHz or 2,0 MHz) depends on the EN 13372 profile selected.
U1a a	Tolerance of Sub- carrier Frequencies	within ± 0,1 %	(Consistent with EN 12253)
U1b	Use of Side Bands	Same data on both sides	(Consistent with EN 12253)
U2 a	OBU (DSRC-VU) Transmitter Spectrum Mask	According to EN12253 1) Out band power: see ETSI EN 300674-1 2) In band power: [U4a] dBm in 500 kHz 3) Emission in any other uplink channel: U2(3)-1 = – 35 dBm in 500 kHz	(Consistent with EN 12253)
U4a a	Maximum Single Side Band E.I.R.P. (boresight)	Two options: U4a-0: – 14 dBm U4a-1: – 21 dBm	According to declared and published specification of equipment designer
U4b a	Maximum Single Side Band E.I.R.P. (35°)	Two options: Not applicable – 17dBm	According to declared and published specification of equipment designer
U5	Polarisation	Left hand circular	(Consistent with EN 12253)
U5a	Cross Polarisation	XPD: In bore sight: (REDCR) RSU r ≥ 15 dB (DSRC-VU) OBU t ≥ 10 dB At – 3 dB: (REDCR) RSU r ≥ 10 dB (DSRC-VU) OBU t ≥ 6 dB	(Consistent with EN 12253)
U6	Sub-Carrier Modulation	2-PSK Encoded data synchronised with sub-carrier: Transitions of encoded data coincide with transitions of sub- carrier.	(Consistent with EN 12253)
U6b	Duty Cycle	Duty Cycle: 50 % ± α, α ≤ 5 %	(Consistent with EN 12253)
U6c	Modulation on Carrier	Multiplication of modulated sub- carrier with carrier.	(Consistent with EN 12253)
U7 a	Data Coding	NRZI (No transition at beginning of ‘1’ bit, transition at beginning of ‘0’ bit, no transition within bit)	(Consistent with EN 12253)
U8 a	Bit Rate	250 kbit/s	(Consistent with EN 12253)
U8a	Tolerance of Bit Clock	Within ± 1 000 ppm	(Consistent with EN 12253)
U9	Bit Error Rate (B.E.R.) for communication	≤10– 6	(Consistent with EN 12253)
U11	Communication Zone	The spatial region within which the DSRC-VU is situated such that its transmissions are received by the REDCR with a B.E.R. of less than that given by U9a.	(Consistent with EN 12253)
U12a a	Conversion Gain (lower limit)	1 dB for each side band Range of angle: Circularly symmetric between bore sight and ± 35° and
		within – 45° ± 45° Corresponding to the plane parallel to the road surface when the DSRC-VU later is installed in the vehicle (Azimuth)	Greater that the specified value range for horizontal angles up to ± 45°, due to the use cases defined in this annex.
U12b a	Conversion Gain (upper limit)	10 dB for each side band	Less than the specified value range for each side band within a circular cone around boresight of ± 45° opening angle
U13	Preamble	Preamble is mandatory.	(Consistent with EN 12253)
U13a	Preamble Length and Pattern	32 to 36 μs modulated with sub- carrier only, then 8 bits of NRZI coded ‘0’ bits.	(Consistent with EN 12253)
U13b	Trailing Bits	The DSRC-VU is permitted to transmit a maximum of 8 bits after the end flag. A RSU (REDCR) is not required to take these additional bits into account.	(Consistent with EN 12253)

5.3.3 Antenna design

5.3.3.1 REDCR antenna

DSC_30 The design of the REDCR antenna shall be a function of commercial design, operating within the limits defined in 5.3.2 which is adapted to optimise the reading performance of the DSRC-REDCR for the specific purpose and read circumstances in which the REDCR has been designed to operate.

5.3.3.2 VU antenna

DSC_31 The design of the DSRC-VU antenna shall be a function of commercial design, operating within the limits defined in 5.3.2 which is adapted to optimise the reading performance of the DSRC-REDCR for the specific purpose and read circumstances in which the REDCR has been designed to operate.

DSC_32 The VU antenna shall be fixed to, or close to, the front windshield of the vehicle as specified in 5.1 above.

DSC_33 In the test environment in a workshop (see section 6.3), a DSRC-VU antenna, affixed according to 5.1 above, shall successfully connect with a standard test communication and successfully provide an RTM transaction as defined within this Appendix, at a distance between 2 and 10 meters, better than 99 % of the time, averaged over 1 000 read interrogations.

5.4 DSRC Protocol requirements for RTM

5.4.1 Overview

DSC_34 The transaction protocol to download the Data across the 5.8 GHz DSRC interface link shall be according to the following steps. This section describes a transaction flow under ideal conditions without retransmissions or communication interrupts.

NOTE The purpose of the initialisation phase (Step 1) is to set up the communication between the REDCR and DSRC-VUs that have entered the 5.8 GHz DSRC (master-slave) transaction zone but have not yet established communication with the REDCR, and to notify the application processes.

— Step 1

Initialisation. The REDCR sends a frame containing a ‘beacon service table’ (BST) that includes the application identifiers (AIDs) in the service list that it supports. In the RTM application this will simply be the service with the AID value = 2 (Freight&Fleet). The DSRC-VU evaluates the received BST, and shall respond (see below) with the list of the supported applications within the Freight&Fleet domain, or shall not respond if none are supported. If the REDCR does not offer AID=2, the DSRC-VU shall not answer to the REDCR.

— Step 2

The DSRC-VU sends a frame containing a request for a private window allocation.

— Step 3

The REDCR sends a frame containing a private window allocation.

— Step 4

The DSRC-VU uses the allocated private window to send a frame containing its vehicle service table (VST). This VST includes a list of all the different application instantiations that this DSRC-VU supports in the framework of AID=2. The different instantiations shall be identified by means of uniquely generated EIDs, each associated with an Application Context Mark parameter value indicating the application and standard supported.

— Step 5

Next the REDCR analyses the offered VST, and either terminates the connection (RELEASE) since it is not interested in anything the VST has to offer (i.e. it is receiving a VST from a DSRC-VU that is not supporting the RTM transaction), or, if it receives an appropriate VST it starts an app instantiation.

— Step 6

To bring this about, the REDCR shall send a frame containing a command to retrieve the RTM data, identifying the RTM application instantiation by specifying the identifier corresponding to the RTM application instantiation (as specified by the DSRC-VU in the VST), and shall allocate a private window.

— Step 7

The DSRC-VU uses the newly allocated private window to send a frame that contains the addressed identifier corresponding to the RTM application instantiation as provided in the VST, followed by the attribute RtmData (payload element + security element).

— Step 8

If there are multiple services requested, the value ‘n’ is changed to the next service reference number and the process repeated.

— Step 9

The REDCR confirms receipt of the data by sending a frame containing a RELEASE command to the DSRC-VU to terminate the session OR if it has failed to validate a successful receipt of the LDPU goes back to step 6.

See Figure 14.6 for a pictorial description of the transaction protocol.

Figure 14.6

RTM over 5,8 GHz DSRC process flow

5.4.2 Commands

DSC_35 The following commands are the only functions used in an RTM transaction phase

— INITIALISATION.request

:

A command, issued from the REDCR in the form of a broadcast with definition of applications that the REDCR supports.

— INITIALISATION.response

:

An answer from the DSRC-VU confirming the connection and containing a list of supported application instances with characteristics and information how to address them (EID).

— GET.request

:

A command, issued from the REDCR to the DSRC-VU, that specifies the application instantiation to be addressed by means of a defined EID, as received in the VST, instructing the DSRC-VU to send the selected attribute(s) with the Data. The objective of the GET command is for the REDCR to obtain the Data from the DSRC-VU.

— GET.response

:

An answer from the DSRC-VU that contains the Data requested.

— ACTION.request ECHO

:

A command, instructing the DSRC-VU to send back data from the DSRC-VU to the REDCR. The objective of the ECHO command is to enable workshops or type approval test facilities to test that the DSRC link is working without needing access to security credentials.

— ACTION.response ECHO

:

An answer from the DSRC VU on the ECHO command.

— EVENT_REPORT.request RELEASE

:

A command, instructing the DSRC-VU that the transaction is ended. The objective of the RELEASE command is to end the session with the DSRC-VU. On receipt of the RELEASE the DSRC-VU shall not respond to any further interrogations under the current connection. Note that according to EN 12834 a DSRC-VU will not connect twice to the same interrogator unless it has been out of the communication zone for 255 seconds or if the Beacon ID of the interrogator is changed.

5.4.3 Interrogation command sequence

DSC_36 From the perspective of the command and response sequence, the transaction is described as follows:

Sequence	Sender		Receiver	Description	Action
1	REDCR	>	DSRC-VU	Initialisation of the communication link — Request	REDCR broadcasts BST
2	DSRC-VU	>	REDCR	Initialisation of the communication link — Response	If BST supports AID=2 then DSRC-VU Requests a private window
3	REDCR	>	DSRC-VU	Grants a private window	Sends Frame containing private window allocation
4	DSRC-VU	>	REDCR	Sends VST	Sends Frame comprising VST
5	REDCR	>	DSRC-VU	Sends GET.request for data in Attribute for specific EID
6	DSRC-VU	>	REDCR	Sends GET.response with requested Attribute for specific EID	Sends Attribute (RTMData, OWSData….) with data for specific EID
7	REDCR	>	DSRC-VU	Sends GET.request for data other Attribute (if appropriate)
8	DSRC-VU	>	REDCR	Sends GET.response with requested Attribute	Sends Attribute with data for specific EID
9	REDCR	>	DSRC-VU	Acknowledges successful receipt of data	Sends RELEASE command which closes transaction
10	DSRC-VU			Closes transaction

An example of the transaction sequence and contents of the exchanged frames is defined in clauses 5.4.7 and 5.4.8

5.4.4 Data structures

DSC_37 The semantic structure of the Data when passed across the 5.8 GHz DSRC interface shall be consistent with what described in this Appendix. The way these data are structured is specified in this clause.

DSC_38 The payload (RTM data) consists of the concatenation of

1.

EncryptedTachographPayload data, which is the encryption of the TachographPayload defined in ASN.1 in section 5.4.5. The method of encryption is described in Appendix 11

2.

DSRCSecurityData, specified in Appendix 11.

DSC_39 The RTM Data is being addressed as RTM Attribute=1 and is transferred in the RTM container = 10.

DSC_40 The RTM Context Mark shall identify the supported standard part in the TARV series of standards (RTM corresponds to Part 9)

The ASN.1 module definition for the DSRC data within the RTM application is defined as follows:

5.4.5 Elements of RtmData, actions performed and definitions

DSC_41 The data values to be calculated by the VU and used to update the secured data in the DSRC-VU shall be calculated according to the rules defined in Table 14.3:

Table 14.3
Elements of RtmData, actions performed and definitions
(1) RTM Data Element	(2) Action performed by the VU		(3) ASN.1 definition of data
RTM1 Vehicle Registration Plate	The VU shall set the value of the tp15638VehicleRegistrationPlate data element RTM1 from the recorded value of the data type VehicleRegistrationIdentification as defined in Appendix 1 VehicleRegistrationIdentification	Vehicle Registration Plate expressed as a string of characters
RTM2 Speeding Event	The VU shall generate a boolean value for data element RTM2 tp15638SpeedingEvent. The tp15638SpeedingEvent value shall be calculated by the VU from the number of Over Speeding Events recorded in the VU in the last 10 days of occurrence, as defined in Annex 1C. If there is at least one tp15638SpeedingEvent in the last 10 days of occurrence, the tp15638SpeedingEvent value shall be set to TRUE. ELSE if there are no events in the last 10 days of occurrence, the tp15638SpeedingEvent shall be set to FALSE.	1 (TRUE) — Indicates irregularities in speed within last 10 days of occurrence
RTM3 Driving Without Valid Card	The VU shall generate a boolean value for data element RTM3 tp15638DrivingWithoutValidCard. The VU shall assign a value of True to the tp15638DrivingWithoutValidCard variable if the VU data has recorded at least one event in the last 10 days of occurrence of type ‘Driving without an appropriate card’ event as defined in Annex 1C. ELSE if there are no events in the last 10 days of occurrence, the tp15638DrivingWithoutValidCard variable shall be set to FALSE.	1 (TRUE) = Indicates invalid card usage
RTM4 Valid Driver Card	The VU shall generate a boolean value for data element RTM4 tp15638DriverCard on the basis of the data stored in the VU and defined in Appendix 1. If no valid driver card is present the VU shall set the variable to TRUE ELSE if a valid driver card is present the VU shall set the variable to FALSE	0 (FALSE) = Indicates a valid driver card
RTM5 Card Insertion while Driving	The VU shall generate a boolean value for data element RTM5. The VU shall assign a value of TRUE to the tp15638CardInsertion variable if the VU data has recorded in the last 10 days of occurrence at least one event of type ‘Card insertion while driving.’ as defined in Annex 1C. ELSE if there are no such events in the last 10 days of occurrence, the tp15638CardInsertion variable shall be set to FALSE.	1 (TRUE) = Indicates card insertion while driving within last 10 days of occurrence
RTM6 Motion Data Error	The VU shall generate a boolean value for data element RTM6. The VU shall assign a value of TRUE to the tp15638MotionDataError variable if the VU data has in the last 10 days of occurrence recorded at least one event of type ‘Motion data error’ as defined in Annex 1C. ELSE if there are no such events in the last 10 days of occurrence, the tp15638MotionDataError variable shall be set to FALSE.	1 (TRUE) = Indicates motion data error within last 10 days of occurrence
RTM7 Vehicle Motion Conflict	The VU shall generate a boolean value for data element RTM7. The VU shall assign a value of TRUE to the tp15638vehicleMotionConflict variable if the VU data has in the last 10 days recorded at least one event of type Vehicle Motion Conflict (value ‘0A’H ). ELSE if there are no events in the last 10 days of occurrence, the tp15638vehicleMotionConflict variable shall be set to FALSE.	1 (TRUE) = Indicates motion conflict within last 10 days of occurrence
RTM8 2nd Driver Card	The VU shall generate a boolean value for data element RTM8 on the basis of Annex 1C (‘Driver Activity Data’ CREW and CO-DRIVER). If a 2nd valid driver card is present the VU shall set the variable to TRUE ELSE if a 2nd valid driver card is not present the VU shall set the variable to FALSE	1 (TRUE) = Indicates a second driver card inserted
RTM9 Current Activity	The VU shall generate a boolean value for data element RTM9. If the current activity is recorded in the VU as any activity other than ‘DRIVING’ as defined in Annex 1C the VU shall set the variable to TRUE ELSE if the current activity is recorded in the VU as ‘DRIVING’ the VU shall set the variable to FALSE	1 (TRUE) = other activity selected; 0 (FALSE) = driving selected
RTM10 Last Session Closed	The VU shall generate a boolean value for data element RTM10. If the last card session was not properly closed as defined in Annex 1C the VU shall set the variable to TRUE. ELSE if the last card session was properly closed the VU shall set the variable to FALSE	1 (TRUE) = improperly closed 0 (FALSE) = properly closed
RTM11 Power Supply Interruption	The VU shall generate an integer value for data element RTM11. The VU shall assign a value for the tp15638PowerSupplyInterruption variable equal to the longest power supply interruption according to Article 9, Reg (EU) 165/2014 of type ‘Power supply interruption’ as defined in Annex 1C. ELSE if in the last 10 days of occurrence there are have been no Power supply interruption events the value of the integer shall be set to 0.	— Number of power supply interruptions in last 10 days of occurrence
RTM12 Sensor Fault	The VU shall generate an integer value for data element RTM12. The VU shall assign to the variable sensorFault a value of: 1 if an event of type ‘35’H Sensor fault has been recorded in the last 10 days, 2 if an event of type GNSS receiver fault (either internal or external with enum values ‘51’H or ‘52’H) has been recorded in the last 10 days. 3 if an event of type ‘53’H External GNSS communication fault has been recorded in the last 10 days of occurrence. 4 If both Sensor Fault and GNSS receiver faults have been recorded in the last 10 days of occurrence 5 If both Sensor Fault and External GNSS communication faults have been recorded in the last 10 days of occurrence 6 If both GNSS receiver fault and External GNSS communication fault have been recorded in the last 10 days of occurrence 7 If all three sensor faults, have been recorded in the last 10 days of occurrence ELSE it shall assign a value of 0 if no events have been recorded in the last 10 days of occurrence	— sensor fault one octet as per data dictionary
RTM13 Time Adjustment	The VU shall generate an integer value (timeReal from Appendix 1) for data element RTM13 on the basis of the presence of Time Adjustment data as defined in Annex 1C. The VU shall assign the value of time at which the last time adjustment data event has occurred. ELSE if no ‘Time Adjustment’ event. as defined in Annex 1C is present in the VU data it shall set a value of 0	Time of the last time adjustment
RTM14 Security Breach Attempt	The VU shall generate an integer value (timeReal from Appendix 1) for data element RTM14 on the basis of the presence of a Security breach attempt event as defined in Annex 1C. The VU shall set the value of the time of the latest security breach attempt event recorded by the VU. ELSE if no ‘security breach attempt’ event as defined in Annex 1C is present in the VU data it shall set a value of 0x00FF.	Time of last breach attempt — Default value =0x00FF
RTM15 Last Calibration	The VU shall generate an integer value (timeReal from Appendix 1) for data element RTM15 on the basis of the presence of Last Calibration data as defined in Annex 1C. The VU shall set the value of time of the latest two calibrations (RTM15 and RTM16), which are set in VuCalibrationData defined in Appendix 1. The VU shall set the value for RTM15 to the timeReal of the latest calibration record.	Time of last calibration data
RTM16 Previous Calibration	The VU shall generate an integer value (timeReal from Appendix 1) for data element RTM16 of the calibration record preceding that of the last calibration ELSE if there has been no previous calibration the VU shall set the value of RTM16 to 0.	Time of previous calibration data
RTM17 Date Tachograph Connected	For data element RTM17 the VU shall generate an integer value (timeReal from Appendix 1). The VU shall set the value of the time of the initial installation of the VU. The VU shall extract this data from the VuCalibrationData (Appendix 1) from the vuCalibrationRecords with CalibrationPurpose equal to: ‘03’H	Date tachograph connected
RTM18 Current Speed	The VU shall generate an integer value for data element RTM18. The VU shall set the value for RTM16 to the last current recorded speed at the time of the latest update of the RtmData.	Last current recorded speed
RTM19 Timestamp	For data element RTM19 the VU shall generate an integer value (timeReal from Appendix 1). The VU shall set the value for RTM19 to the time of the latest update of the RtmData.	Timestamp of current TachographPayload record

5.4.6 Data transfer mechanism

DSC_42 Payload data defined previously are requested by the REDCR after initialisation phase, and consequently transmitted by the DSRC-VU in the allocated window. The command GET is used by the REDCR to retrieve data.

DSC_43 For all DSRC exchanges, data shall be encoded using PER (Packed Encoding Rules).

5.4.7 Detailed DSRC transaction description

DSC_44 Initialisation is performed according to DSC_44 — DSC_48 and Tables 14.4 — 14.9. In the initialisation phase, the REDCR starts sending a frame containing a BST (Beacon Service Table) according to EN 12834 and EN 13372, 6.2, 6.3, 6.4 and 7.1 with settings as specified in the following Table 14.4.

Table 14.4
Initialisation — BST frame settings
Field	Settings
Link Identifier	Broadcast address
BeaconId	As per EN 12834
Time	As per EN 12834
Profile	No extension, 0 or 1 to be used
MandApplications	No extension, EID not present, Parameter not present, AID= 2 Freight&Fleet
NonMandApplications	Not present
ProfileList	No extension, number of profiles in list = 0
Fragmentation header	No fragmentation
Layer 2 settings	Command PDU, UI command

A practical example of the settings specified in Table 14.4, with an indication of bit encodings, is given in the following Table 14.5.

Table 14.5
Initialisation — BST frame contents example
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Broadcast ID		Broadcast address
3	MAC Control Field		Command PDU
4	LLC Control field		UI command
5	Fragmentation header		No fragmentation
6	BST		Initialisation request
	SEQUENCE {
	OPTION indicator BeaconID SEQUENCE { ManufacturerId INTEGER (0..65535)		NonMand applications not present
			Manufacturer Identifier
7
8
	IndividualID INTEGER (0..134217727) }		27 bit ID available for manufacturer
9
10
11
12	Time INTEGER (0..4294967295)		32 bit UNIX real time
13
14
15
16	Profile INTEGER (0..127,...)		No extension. Example profile 0
17	MandApplications SEQUENCE (SIZE(0..127,...)) OF {		No extension, Number of mandApplications = 1
18	SEQUENCE {
	OPTION indicator		EID not present
	OPTION indicator		Parameter not present
	AID DSRCApplicationEntityID } }		No extension. AID= 2 Freight&Fleet
19	ProfileList SEQUENCE (0..127,...) OF Profile }		No extension, number of profiles in list = 0
20	FCS		Frame check sequence
21
22	Flag		End Flag

DSC_45 A DSRC-VU, when receiving a BST, requires the allocation of a private window, as specified by EN 12795 and EN 13372, 7.1.1, with no specific RTM settings. Table 14.6 provides an example of bit encoding.

Table 14.6
Initialisation — Private window allocation request frame contents
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of specific DSRC-VU
3
4
5
6	MAC Control field		Private window request
7	FCS		Frame check sequence
8
9	Flag		End Flag

DSC_46 The REDCR then answers by allocating a private window, as specified by EN 12795 and EN 13372, 7.1.1 with no specific RTM settings.

Table 14.7 provides an example of bit encoding.

Table 14.7
Initialisation — Private window allocation frame contents
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of the specific DSRC-VU
3
4
5
6	MAC Control field		Private window allocation
7	FCS		Frame check sequence
8
9	Flag		End Flag

DSC_47 The DSRC-VU, when receiving the private window allocation, sends its VST (Vehicle Service Table) as defined in EN 12834 and EN 13372, 6.2, 6.3, 6.4 and 7.1 with settings as specified Table 14.8, using the allocated transmission window.

Table 14.8
Initialisation — VST frame settings
Field	Settings
Private LID	As per EN 12834
VST parameters	Fill=0, then for each supported application: EID present, parameter present, AID=2, EID as generated by the OBU
Parameter	No extension, Contains the RTM Context Mark
ObeConfiguration	The optional ObeStatus field may be present, but shall not be used by the REDCR
Fragmentation header	No fragmentation
Layer 2 settings	Command PDU, UI command

DSC_48 The DSRC-VU shall support the ‘Freight and Fleet’ application, identified by the Application Identifier ‘2’. Other Application Identifiers may be supported, but shall not be present in this VST, as the BST only requires AID=2. The ‘Applications’ field contains a list of the supported application instances in the DSRC-VU. For each supported application instantiation, a reference to the appropriate standard is given, made of an Rtm Context mark, which is composed of an OBJECT IDENTIFIER representing the related standard, its part (9 for RTM) and possibly its version, plus an EID that is generated by the DSRC-VU, and associated to that application instance.

A practical example of the settings specified in Table 14.8, with an indication of bit encodings, is given in Table 14.9.

Table 14.9
Initialisation — VST frame contents example
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of the specific DSRC-VU
3
4
5
6	MAC Control field		Command PDU
7	LLC Control field		UI command
8	Fragmentation header		No fragmentation
9	VST SEQUENCE {		Initialisation response
	Fill BIT STRING (SIZE(4))		Unused and set to 0
10	Profile INTEGER (0..127,...) Applications SEQUENCE OF {		No extension. Example profile 0
11			No extension, 1 application
12	SEQUENCE {
	OPTION indicator		EID present
	OPTION indicator		Parameter present
	AID DSRCApplicationEntityID		No extension. AID= 2 Freight&Fleet
13	EID Dsrc-EID		Defined within the OBU and identifying the application instance.
14	Parameter Container {		No extension, Container Choice = 02, Octet string
15			No extension, Rtm Context Mark length = 8
16	Rtm-ContextMark::= SEQUENCE { StandardIdentifier standardIdentifier		Object Identifier of the supported standard, part, and version. Example: ISO (1) Standard (0) TARV (15638) part9(9) Version1 (1). First octet is 06H, which is the Object Identifier Second octet is 06H, which is its length. Subsequent 6 octets encode the example Object Identifier Note that only one element of the sequence is present (the optional RtmCommProfile element is omitted)
17
18
19
20
21
22
23
24	ObeConfiguration Sequence {
	OPTION indicator		ObeStatus not present
	EquipmentClass INTEGER (0..32767)
25
26	ManufacturerId INTEGER (0..65535)		Manufacturer identifier for the DSRC-VU as described in ISO 14816 Register
27
28	FCS		Frame check sequence
29
30	Flag		End Flag

DCS_49 The REDCR then reads the data by issuing a GET command, conforming to the GET command defined in EN 13372, 6.2, 6.3, 6.4 and EN 12834, with settings as specified in Table 14.10.

Table 14.10
Presentation — GET request frame settings
Field	Settings
Invoker Identifier (IID)	Not present
Link Identifier (LID)	Link address of the specific DSRC-VU
Chaining	No
Element Identifier (EID)	As specified in the VST. No extension
Access Credentials	No
AttributeIdList	No extension, 1 attribute, AttributeID = 1 (RtmData)
Fragmentation	No
Layer2 settings	Command PDU, Polled ACn command

Table 14.11 shows an example of reading the RTM data.

Table 14.11
Presentation — Get Request frame example
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of the specific DSRC-VU
3
4
5
6	MAC Control field		Command PDU
7	LLC Control field		Polled ACn command, n bit
8	Fragmentation header		No fragmentation
9	Get.request SEQUENCE {		Get request
	OPTION indicator		Access Credentials not present
	OPTION indicator		IID not present
	OPTION indicator		AttributeIdList present
	Fill BIT STRING(SIZE(1))		Set to 0.
10	EID INTEGER(0..127,…)		The EID of the RTM application instance, as specified in the VST. No extension
11	AttributeIdList SEQUENCE OF { AttributeId }}		No extension, number of attributes = 1
12			AttributeId=1, RtmData. No extension
13	FCS		Frame check sequence
14
15	Flag		End Flag

DSC_50 The DSRC-VU, when receiving the GET request, sends a GET response with the requested data conforming to the GET response defined in EN 13372, 6.2, 6.3, 6.4 and EN 12834, with settings as specified in Table 14.12.

Table 14.12
Presentation — GET response frame settings
Field	Settings
Invoker Identifier (IID)	Not present
Link Identifier (LID)	As per EN 12834
Chaining	No
Element Identifier (EID)	As specified in the VST.
Access Credentials	No
Fragmentation	No
Layer2 settings	Response PDU, Response available and command accepted, ACn command

Table 14.13 shows an example of reading the RTM data.

Table 14.13
Presentation — Response frame contents example
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of the specific DSRC-VU
3
4
5
6	MAC Control field		Response PDU
7	LLC Control field		Response available, ACn command n bit
8	LLC Status field		Response available and command accepted
9	Fragmentation header		No fragmentation
10	Get.response SEQUENCE {		Get response
	OPTION indicator		IID not present
	OPTION indicator		Attribute List present
	OPTION indicator		Return status not present
	Fill BIT STRING(SIZE(1))		Not used
11	EID INTEGER(0..127,…)		Responding from the RTM application Instance. No extension,
12	AttributeList SEQUENCE OF {		No extension, number of attributes = 1
13	Attributes SEQUENCE { AttributeId		No extension, AttributeId=1 (RtmData)
14	AttributeValue CONTAINER {		No extension, Container Choice = 1010.
15			RtmData
16
17
…		…
n	}}}}
n+1	FCS		Frame check sequence
n+2
n+3	Flag		End Flag

DSC_51 The REDCR then closes the connection by issuing a EVENT_REPORT, RELEASE command conforming to EN 13372, 6.2, 6.3, 6.4 and EN 12834,7.3.8, with no specific RTM settings. Table 14.14 shows a bit encoding example of the RELEASE command.

Table 14.14
Termination. EVENT_REPORT Release frame contents
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of the specific DSRC-VU
3
4
5
6	MAC Control field		The frame contains a command LPDU
7	LLC Control field		UI command
8	Fragmentation header		No fragmentation
9	EVENT_REPORT.request SEQUENCE {		EVENT_REPORT (Release)
	OPTION indicator		Access Credentials not present
	OPTION indicator		Event parameter not present
	OPTION indicator		IID not present
	Mode BOOLEAN		No response expected
10	EID INTEGER (0..127,…)		No extension, EID = 0 (System)
11	EventType INTEGER (0..127,…) }		Event type 0 = Release
12	FCS		Frame check sequence
13
14	Flag		End Flag

DSC_52 The DSRC-VU is not expected to answer to the Release command. The communication is then closed.

5.4.8 DSRC Test transaction description

DSC_53 Full tests that include securing the data, need to be carried out as defined in Appendix 11 Common Security Mechanisms, by authorised persons with access to security procedures, using the normal GET command as defined above.

DSC_54 Commissioning and periodic inspection tests that require decrypting and comprehension of the decrypted data content shall be undertaken as specified in Appendix 11 Common Security Mechanisms and Appendix 9, Type Approval List of Minimum required tests.

However, the basic DSRC communication can be tested by the command ECHO. Such tests may be required on commissioning, at periodic inspection, or otherwise to the requirement of the competent control authority or Regulation (EU) No 165/2014 (See 6 below)

DSC_55 In order to effect this basic communication test, the ECHO command is issued by the REDCR during a session, i.e., after an initialisation phase has been completed successfully. The sequence of interactions is thus similar to that of an interrogation:

— Step 1

The REDCR sends a ‘beacon service table’ (BST) that includes the application identifiers (AIDs) in the service list that it supports. In the RTM applications this will simply be the service with the AID value = 2.

The DSRC-VU evaluates the received BST, and where it identifies that the BST is requesting Freight&Fleet (AID = 2), the DSRC-VU shall respond. If the REDCR does not offer AID=2, the DSRC-VU shall shut down its transaction with the REDCR.

— Step 2

The DSRC-VU sends a request for a private window allocation.

— Step 3

The REDCR sends a private window allocation.

— Step 4

The DSRC-VU uses the allocated private window to send its vehicle service table (VST). This VST includes a list of all the different application instantiations that this DSRC-VU supports in the framework of AID=2. The different instantiations shall be identified by means of uniquely EIDs, each associated with a parameter value indicating the instance of the application that is supported.

— Step 5

Next the REDCR analyses the offered VST, and either terminates the connection (RELEASE) since it is not interested in anything the VST has to offer (i.e., it is receiving a VST from a DSRC-VU that is not an RTM VU, or, if it receives an appropriate VST it starts an app instantiation.

— Step 6

The REDCR shall issue a command (ECHO) to the specific DSRC-VU, and allocates a private window.

— Step 7

The DSRC-VU uses the newly allocated private window to send an ECHO response frame.

The following tables give a practical example of an ECHO exchange session.

DSC_56 Initialisation is performed according to 5.4.7 (DSC_44 — DSC_48) and Tables 14.4 — 14.9

DSC_57 The REDCR then issues an ACTION, ECHO command conforming to ISO 14906, containing 100 octets of data and with no specific settings for RTM. Table 14.15 shows the contents of the frame sent by the REDCR.

Table 14.15
ACTION, ECHO request frame example
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of the specific DSRC-VU
3
4
5
6	MAC Control field		Command PDU
7	LLC Control field		Polled ACn command, n bit
8	Fragmentation header		No fragmentation
9	ACTION.request SEQUENCE {		Action request (ECHO)
	OPTION indicator		Access Credentials not present
	OPTION indicator		Action parameter present
	OPTION indicator		IID not present
	Mode BOOLEAN		Response expected
10	EID INTEGER (0..127,…)		No extension, EID = 0 (System)
11	ActionType INTEGER (0..127,…)		No extension, Action type ECHO request
12	ActionParameter CONTAINER {		No extension, Container Choice = 2
13			No extension. String length = 100 octets
14			Data to be echoed
…		…
113	}}
114	FCS		Frame check sequence
115
116	Flag		End Flag

DSC_58 The DSRC-VU, when receiving the ECHO request, sends an ECHO response of 100 octets of data by reflecting the received command, according to ISO 14906, with no specific settings for RTM. Table 14.16 shows a bit level encoding example.

Table 14.16
ACTION, ECHO response frame example
Octet #	Attribute/Field	Bits in octet	Description
1	FLAG		Start flag
2	Private LID		Link address of the specific VU
3
4
5
6	MAC Control field		Response PDU
7	LLC Control field		ACn command n bit
8	LLC status field		Response available
9	Fragmentation header		No fragmentation
10	ACTION.response SEQUENCE {		ACTION response (ECHO)
	OPTION indicator		IID not present
	OPTION indicator		Response parameter present
	OPTION indicator		Return status not present
	Fill BIT STRING (SIZE (1))		Not used
11	EID INTEGER (0..127,…)		No extension, EID = 0 (System)
12	ResponseParameter CONTAINER {		No extension, Container Choice = 2
13			No extension. String length = 100 octets
14			Echoed data
…		…
113	}}
114	FCS		Frame check sequence
115
116	Flag		End Flag

5.5 Support for Directive 2015/71/EC

5.5.1 Overview

DSC_59 To support the Directive 2015/719/EC on the maximal weights and dimensions for heavy goods vehicles, the transaction protocol to download OWS data across the 5.8 GHz DSRC interface link will be the same as that used for the RTM data (see 5.4.1), the only difference being that the Object Identifier that relates to the TARV standard will be addressing the ISO 15638 standard (TARV) Part 20 related to WOB/OWS.

5.5.2 Commands

DSC_60 The commands used for an OWS transaction will be the same as those used for an RTM transaction.

5.5.3 Interrogation command sequence

DSC_61 The interrogation command sequence for OWS data will be the same as for RTM data.

5.5.4 Data structures

DSC_62 The payload (OWS data) consists of the concatenation of

1.

EncryptedOwsPayload data, which is the encryption of the OwsPayload defined in ASN.1 in section 5.5.5. The method of encryption shall be the same adopted for the RtmData, which is specified in Appendix 11

2.

DSRCSecurityData, calculated with the same algorithms adopted for the RtmData, which is specified in Appendix 11.

5.5.5 ASN.1 module for the OWS DSRC transaction

DSC_63. The ASN.1 module definition for the DSRC data within the RTM application is defined as follows:

5.5.6 Elements of OwsData, actions performed and definitions

The elements of OwsData are defined to support Directive 2015/719/EC on the maximal weights and dimensions for heavy goods vehicles. Their meaning is:

• recordedWeight represents the total measured weight of the heavy goods vehicle with a resolution of 10 Kg as defined in EN ISO 14906. For example, a value of 2500, represent a weight of 25 tons.

• axlesConfiguration represents the configuration of the heavy goods vehicle as number of axles. The configuration is defined with the bit mask of 20 bits (extended from EN ISO 14906).

  A bit mask of 2 bits represents the configuration of an axle with the following format:

  • Value 00B means that value is ‘non available’ because the vehicle does not have equipment to collect the weight on the axle.

  • Value 01B means that the axle is not present.

  • Value 10B means that the axle is present and the weight has been calculated and collected and it is provided in the axlesRecordedWeight field.

  • Value 11B is reserved for future uses.

  The last 4 bits are reserved for future uses.

  Number of Axles
  Number of axles on tractor unit			Number of axles on trailer
  00/01/10/11	00/01/10/11	00/01/10/11	00/01/10/11	00/01/10/11	00/01/10/11	00/01/10/11	00/01/10/11	00/01/10/11	00/01/10/11	RFU (4 bits)

• axlesRecordedWeight represent the specific weight recorded for each axle with a resolution of 10 Kg. Two octets are used for each axle. For example, a value of 150, represent a weight of 1 500 Kgs.

The other data types are defined in 5.4.5.

5.5.7 Data transfer mechanisms

DSC_64 The Data transfer mechanism for OWS data between the Interrogator and the DSRC facility in the vehicle shall be the same as for RTM data (see 5.4.6).

DSC_65 The Data transfer between the platform collecting the maximal weights data and the DSRC facility in the vehicle shall be based on the physical connection and interfaces and protocol defined in section 5.6.

5.6 Data transfer between the DSRC-VU and VU

5.6.1 Physical Connection and interfaces

DSC_66 The connection between the VU and the DSRC-VU can be either by physical cable or short range wireless communication based on Bluetooth v4.0 BLE.

DSC_67 Regardless of the choice of the physical connection and interface, the following requirements shall be satisfied:

DSC_68

a) In order that different suppliers may be contracted to supply the VU and the DSRC-VU, and indeed different batches of DSRC-VU, the connection between the VU and the DSRC-VU shall be an open standard connection. The VU shall connect with the DSRC-VU either

i)

using fixed cable of at least 2 meters, using a Straight DIN 41612 H11 Connector — 11 pin approved male connector from the DSRC-VU to match a similar DIN/ISO approved female connector from the VU device,

ii)

using Bluetooth Low Energy (BLE)

iii)

using a standard ISO 11898 or SAE J1939 connection

DSC_69

b) the definition of the interfaces and connection between the VU and DSRC-VU must support the application protocol commands defined in 5.6.2. and

DSC_70

c) the VU and DSRC-VU must support the operation of the data transfer via the connection in regard to performance and power supply.

5.6.2 Application Protocol

DSC_71 The application protocol between the VU Remote Communication facility and DSRC-VU is responsible for periodically transferring the remote communication data from the VU to the DSRC.

DSC_72 The following main commands are identified:

1.

Initialisation of the communication link — Request

2.

Initialisation of the communication link — Response

3.

Send Data with Identifier of the RTM application and Payload defined by RTM Data

4.

Acknowledgment of the data

5.

Termination of the communication link — Request

6.

Termination of the communication link — Response

DSC_73 In ASN1.0, the previous commands may be defined as:

DSC_74 The description of the commands and parameters is following:

• is used to initialize the communication link. The command is sent by the VU to the DSRC-VU. The LinkIdentifier is set by the VU and communicated to the DSRC-VU to track a specific communication link.

  (Note: this is to support future links and other application/modules like Weighing on board).

• is used by the DSRC-VU to provide the response of the request to initialize the communication link. The command is sent by the DSRC-VU to the VU. The command provides the result of the initialisation as answer = 1 (Success) or =0 (Failure).

DSC_75 The initialization of the communication link shall be done only after installation, calibration, and start of the engine/VU is switched on.

• is used to by the VU to send the signed RCDTData (i.e., the remote communication Data) to the DSRC-VU. The data will be sent every 60 seconds. The DataTransactionId parameter identifies the specific transmission of data. The LinkIdentifier is also used to ensure that the appropriate link is correct.

• is sent by the DSRC-VU to provide the feedback to the VU on the reception of the data from a command identified by the DataTransactionId parameter. The Answer parameter is 1 (Success) or =0 (Failure). If a VU receives more than three answers equal to 0 or if the VU does not receive a RCDT Data Acknowledgment for a specific previously sent RCDT- Send Data with a specific DataTransactionId, the VU will generate and record an event.

• is sent by the VU to DSRC-VU to terminate a link for a specific LinkIdentifier.

DSC_76 At the restart of the DSRC-VU or a VU, all the existing Communication Links should be removed as there could be ‘dangling’ Links due to the sudden shutdown of a VU.

• is sent by the DSRC-VU to the VU to confirm the request of termination of the link by the VU for the specific LinkIdentifier.

5.7 Error handling

5.7.1 Recording and communication of the Data in the DSRC-VU

DSC_77 The Data shall be provided, already secured, by the VUSM function to the DSRC-VU. The VUSM shall verify that data recorded in the DSRC-VU has been recorded correctly. The recording and reporting of any errors in the transfer of data from the VU to the memory of the DSRC-VU shall be recorded with type EventFaultType and enum value set to ‘62’H Remote Communication Facility communication fault together with the timestamp.

DSC_78 The VU shall maintain a file identified by a unique name that is easily identifiable by inspectors for the purpose of recording ‘VU internal communication failures’.

DSC_79 If the VUPM attempts to obtain VU data from the security module (to pass to the VU-DSRC), but fails to do so, it shall record that failure with type EventFaultType and enum value set to ‘62’H Remote Communication Facility' communication fault together with the timestamp. The failure of the communication is detected when a message is not received for the related (i.e., with the same DataTransactionId messages) for more than three consecutive times.

5.7.2 Wireless Communication errors

DSC_80 Communication error handling shall be consistent with the related DSRC standards, namely EN 300 674-1, EN 12253, EN 12795, EN 12834 and the appropriate parameters of EN 13372.

5.7.2.1 Encryption and signature errors

DSC_81 Encryption and signature errors shall be handled as defined in Appendix 11 Common Security Mechanisms and are not present in any error messages associated with the DSRC transfer of data.

5.7.2.2 Recording of errors

The DSRC medium is a dynamic wireless communication in an environment of uncertain atmospheric and interference conditions, particularly in the ‘portable REDCR’ and ‘moving vehicle’ combinations involved in this application. It is therefore necessary to ascertain the difference between a ‘read failure’ and an ‘error’ condition. In a transaction across a wireless interface, read failure is common and the consequence is usually to retry, i.e. rebroadcast the BST and reattempt the sequence, which will in most circumstances lead to a successful communication connection and transfer of data, unless the target vehicle moves out of range during the time required to retransmit. (A ‘successful’ instance of a ‘read’ may have involved several attempts and retries).

Read failure may be because the antennas were not paired properly (failure of ‘aiming’); because one of the antennas is shielded — this may be deliberate, but also can be caused by the physical presence of another vehicle; radio interference, especially from circa 5.8 GHz WIFI or other public access wireless communications, or may be caused by radar interference, or difficult atmospheric conditions (e.g. during a thunderstorm); or simply by moving out of the range of the DSRC communication. Individual instances of read failures, by their nature, cannot be recorded, simply because the communication simply did not occur.

However, if the agent of the competent control authority targets a vehicle and attempts to interrogate its DSRC-VU, but no successful transfer of data ensues, this failure could have occurred because of deliberate tampering, and therefore the agent of the competent control authority needs a means to log the failure, and alert colleagues downstream that there may be a violation. The colleagues can then stop the vehicle and carry out a physical inspection. However, as no successful communication has taken place, the DSRC-VU cannot provide data concerning the failure. Such reporting shall therefore be a function of REDCR equipment design.

‘Failure to read’ is technically different to an ‘error’. In this context an ‘error’ is the acquisition of a wrong value.

Data transferred to the DSRC-VU is supplied already secured, therefore must be verified by the supplier of the data (see 5.4).

Data subsequently transferred across the air interface is checked by cyclic redundancy checks at the communications level. If the CRC validates, then the data is correct. If the CRC does not validate, the data is retransmitted. The probability that data could successfully pass through a CRC incorrectly is statistically so highly improbable that it may be discounted.

If the CRC does not validate and there is no time to retransmit and receive the correct data, then the result will not be an error, but an instantiation of a specific type of read failure.

The only meaningful ‘failure’ data that can be recorded is that of the number of successful initiations of transactions that occur, that do not result in a successful transfer of data to the REDCR.

DSC_82 The REDCR shall therefore record, time-stamped, the number of occasions where the ‘initialisation’ phase of a DSRC interrogation is successful, but the transaction terminated before the Data was successfully retrieved by the REDCR. This data shall be available to agent of the competent control authority and shall be stored in the memory of the REDCR equipment. The means by which this is achieved shall be a matter of product design or the specification of a competent control authority.

The only meaningful ‘error’ data that can be recorded is the number of occasions where the REDCR fails to decrypt the Data received. However, it should be noted that this will only relate to the efficiency of the REDCR software. Data may be technically decrypted, but make no semantic sense.

DSC_83 The REDCR shall therefore record, time-stamped, the number of occasions where it has attempted but failed to decipher data received across the DSRC interface.