Through this RFI process, Sydney Trains intend to obtain market insight to inform its future strategy in relation to:
•Technical solutions for upgrading the GSM-R packet core to address capacity
•Potential options for maintenance support of the system
•Managing technology obsolescence issues
Sydney Trains has a Digital Train Radio System (DTRS) for meeting its train radio communication requirements. The DTRS is a GSM-R based system. DTRS is the primary train radio system providing voice and data services to all Sydney Trains electric and diesel passenger fleet for day-to-day train operations.
The current DTRS consists of the following:
•2 x Critical Core Sites
•1 x Non-critical Core Sites
•360 (approx.) x base sites located across the Sydney Train electrified network
•100 (approx.) x dispatcher terminals located across the network
•800 (approx.) x cab radios
•700 (approx.) x hand portables
Further details have been provided in Appendix A, Sydney Trains DTRS System Architecture. The DTRS operates in the DSC1800 band and supporting GPRS and EDGE packet switched data services, compliant to EIRENE SRS (15.0.0) /FRS (7.0.0) and 3GPP rel.4 standards. The current packet core (i.e. SGSN, GGSN) is configured in geographically distributed redundant configuration to achieve the availability target as per the DTRS Technical specification. The DTRS packet core has a pair of SGSNs in a pool setup and a pair of GGSN. The pair of GGSN nodes work in an active-active configuration. The Radio Access Network (RAN) operates in active/standby mode which points the subscriber traffic to SGSN pool. In addition there is a SGSN and GGSN in the DTRS test environment (i.e. Basic Configuration Test System - BCTS). There are currently approximately 800 standard DTRS Cab Radios and 700 DTRS handhelds in service. Due to planned projects, this number is likely to increase gradually in next few years and reach 10,000 radio terminals.
The DTRS packet switched data services are used predominantly for maintenance and incident investigation purposes. The current capacity limitation of the GGSN/SGSN nodes as defined by the software license is at 1Mbps. Sydney Trains are looking to upgrade the DTRS packet core to address the capacity and hardware obsolescence. Sydney Trains is also seeking to identify support and maintenance options for the DTRS network post the current support contract expiry in July 2021.
