8Telecommunications requirements#

The telecommunications requirements defined in MRTS201 General Equipment Requirements apply to work provided under this Technical Specification. Vehicles used for mounting TVMS shall comply with the communication requirements of the host vehicle specified in the Queensland MUTCD Part 3 and this Technical Specification in order of preference.

8.1Local site communications#

8.1.1Between CU and LED display#

Communication between the local CU and LED sign display shall be via a direct wired connection. The communications system shall be secure, tamperproof and fully-enclosed. Messages transmitted from the CU to the LED display shall be displayed within 50 ms of being sent.

8.1.2Between configuration software (locally, for example, on laptop) and CU#

Refer to Clause 8.4.

8.1.3Between CU(s) and handheld SRD(s)#

Provision shall be made for communication between the CU(s) and SRD(s) via a wired or wireless connection.

For wired connection between the CU and the SRD, the connecting lead shall be at least 15 m.

Wireless connection between the CU and the SRD shall use local encrypted wireless communication technology, such as ultra-high frequency (UHF) radio band or other reliable wireless technology. The wireless SRD shall be as specified in Clause 9.7 below.

The SRD and CU shall communicate reliably over wireless point to point ranges of at least 150 m.

Where an SRD has requested a change of message on a TVMS sign CU, the message change shall be completed within 250 ms of the request: that is, the respective CU's display shall energise the requested message LED pixels.

Any radio frequency communications antennas shall be positioned at the highest point on the TVMS sign to make effective use of available signal gain and avoid line of sight signal attenuation by objects such as concrete barriers and shrubs.

Wireless communication shall be compliant to Australian Communications and Media Authority (ACMA) requirements.

8.2Remote site communications#

The requirement for remote site communications may not be applicable to vehicle-mounted TVMS that comply with the Queensland MUTCD Part 3. The following apply to trailer mount and concrete block mount TVMS.

8.2.1Between CU and RSCS#

Communication between the CU and the RSCS software shall be via a secure wireless connection using a third-party 4G / 5G mobile service provider using secure interface and access protocols as detailed in Clause 10.1 below. All communication over third-party communications network shall provide adequate privacy and integrity of data to the satisfaction of the Principal.

The carrier selected shall have sufficient and reliable coverage at the project site.

Setup and ongoing provision of the mobile service required is the responsibility of the Contractor who owns the TVMS sign.

All messages transmitted from the RSCS software to and from CU embedded firmware shall not exceed 4.0 seconds.

8.2.2CU and SMS notification system#

Communication between the unit controller and a mobile phone for the purposes of the transmission of critical alert SMS notifications as defined in Clause 9.15 below shall be via a third-party SMS mobile service provider. The telecommunications carrier selected shall have sufficient and reliable coverage at the project site.

8.3Communications timeout#

For any SRD or RSCS to CU communications, periodic timeout check shall be ignored, and the display shall remain on indefinitely until requested otherwise.

For Blank / Maintenance mode, if the configuration software remains inactive for a period as defined in Appendix A, then the user session will be terminated, the sign display blanked and the user will need to logon again and establish another session.

All time-out periods shall be software configurable with ranges and default values stated in Appendix A.

8.4CU communications ports#

8.4.1Maintenance communication port#

It shall be possible to control and interrogate the TVMS via a 10/100 Base-T Ethernet maintenance communications port via the TVMS controller. The Ethernet port shall allow local and remote communications via a laptop computer installed with TVMS messaging and diagnostics software provided by the supplier. The maintenance communications port shall also allow remote connection of a similar computer via a modem.

A physical change of connection between remote and local operation shall not require further interaction from the user, nor in any way interrupt operation or require rebooting of TVMS control system or computer / software. The hardware handshaking lines of the Ethernet interface shall be used such that connection / disconnection of the maintenance PC (either locally or by modem) results in the immediate initiation / termination of the maintenance port communications session with the TVMS.

The TVMS control and diagnostics software shall be capable of operating at all possible modem connection speeds.

8.4.2Control communications port#

It shall be possible to control and interrogate the TVMS via either of EIA / RS-232 or 10/100 Base-T Ethernet or both control communications ports. The control communications port shall allow local connection of a field processor / modem for communications with STREAMS.

While a PC / laptop computer is connected to the TVMS via the maintenance communications port, control of the TVMS via the control ports shall be inhibited; however, status and diagnostic interrogation by STREAMS via the control ports shall be maintained.

Complete control and monitoring by STREAMS shall be maintained through either, and / or both control communications ports as determined by telecommunications infrastructure provided at each site. Where communications equipment is connected to both control communications ports, the primary port shall be used for control commands to / from the TVMS, and the secondary port shall be used for status-only communications with the TVMS. Where communications equipment is connected to only one control communications port (or in the case of failure of either communications port or attached equipment), the TVMS shall automatically revert to full control and status communications through the active port. TVMS communications software shall be capable of operating at all possible modem connection and/or serial / Ethernet port speeds.

8.5Labelling and identification#

The SRD and CU shall each have a configurable unique communications ID, for example, a 3-digit integer between 001 and 255. Communications messages between the CU and SRD shall include a checksum unique to each TVMS site and shall be computed based on the message information exchanged to ensure integrity of the communication is upheld. The checksum shall be available for confirmation by the RSCS that the message frames at each TVMS site are the same as those stored within the RSCS software. The checksum shall be verified periodically and recomputed each time the message frames is changed and/or that the CU is reset / rebooted.

8.5.1CU ID#

A TVMS CU unique ID shall be configured through RSCS or configuration software. Any communications messages transmitted by a CU shall embed the CU’s respective ID. A physical label displaying this ID must be clearly visible on the TVMS.

8.5.2SRD ID#

A unique SRD ID shall be configured on an SRD through a settable dipswitch or electronically configured using the RSCS or configuration software.