ZTE has launched a 4G LTE broadband solution for the railway industry. The solution is based on ZTE’s B-TrunC standard and is also compatible with existing GSM-R system. It also supports the false answer supervision (FAS) system, multimedia dispatching and the public land mobile network (PLMN)/public switched telephone network (PSTN) networks.
The system supports video group calls, group, private, emergency and broadcast calls and call priority functions. It also offers multimedia trunked dispatching, video phones, real-time video surveillance and release of comprehensive passenger information.
ZTE argues that trunking performance indicators show that the new LTE-R solution delivers significant performance improvements compared to existing GSM-R railway communication systems and LTE upper-layer applications. End-to-end call setup delay is less than 350 milliseconds, while floor seizure delay is less than 200 milliseconds.
The LTE-R solution comprises systems for video surveillance and passenger information, developed with test access unit (TAU) technology, offering enhanced railway security. Video surveillance is used in dangerous railway areas and on train carriages to improve rail operations, maintenance and emergency response, providing passengers with updated travel information, news and online resources.
Additionally, ZTE’s innovative portable railway emergency equipment integrates the BaseBand Unit, Remote Radio Unit and core network equipment into a 20-inch trolley case to provide on-site relief during railway emergencies.
ZTE’s LTE-R solution comprises of a frequency-division duplex (FDD) and a time-division duplex (TDD) solution. The FDD solution is based on its software defined radio (SDR) platform, in which one base station supports both GSM-R and LTE-R services.
The TDD solution supports the existing GSM-R 900 MHz spectrum, as well as the European GSM-R extended spectrum. Neither the GSM-R system nor the LTE-R system require a protection band on the spectrum, so the FDD solution provides higher frequency efficiency.
The TDD solution supports dedicated spectrums on low frequency bands below 1 GHz, thus providing better broadcast features and high-speed performance. Taking advantage of the flexible uplink/downlink proportion feature of the LTE TDD mode, the TDD solution can also provide users with timeslot proportion choices, such as 1:3, 2:2, and 3:1, based on service features.
LTE-R provides flexible network architectures, such as shared-site dual-network architecture and interweaving network architecture, and can also support hot standby of all boards on the baseband unit (BBU) and hot standby of remote radio unit (RRU) hardware.
The self-adaptability frequency compensation algorithm developed by ZTE based on scenario features ensures that there is basically no performance loss at the speed of 300km/H.
The super-cell algorithm developed by ZTE reduces the number of handovers between adjacent cells, thus guaranteeing the level of quality of service. Cloud Radio, a patented ZTE technology, reduces inter-cell interference and improves the boundary throughput.