Core performance indicators show that the new LTE-R solution offers significant performance improvements compared to existing GSM-R rail communication systems and upper-layer LTE applications. The full call setup delay is less than 350 milliseconds, while the ground connection delay is less than 200 milliseconds.
The LTE-R solution comprises video surveillance and passenger information systems, developed with Test Access Unit (TAU) technology, offering enhanced railway security. Video surveillance is used in hazardous areas and train cars to improve railway operations, maintenance, and emergency response, providing passengers with up-to-date 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 wheeled suitcase to provide on-site assistance during railway emergencies.
ZTE's LTE-R solution comprises both Frequency Division Duplex (FDD) and Time Division Duplex (TDD). The FDD solution is based on the industry-leading Software Defined Radio (SDR) platform, where a single base station supports both GSM-R and LTE-R services. The TDD solution supports the existing 900 MHz GSM-R spectrum, as well as the extended European GSM-R spectrum. Neither GSM-R nor LTE-R requires a shielded band in the spectrum, so the FDD solution provides greater frequency efficiency. The TDD solution supports dedicated spectrum in low-frequency bands below 1 GHz, thus providing improved transmission characteristics and high-speed performance. Taking advantage of the flexible uplink/downlink ratio feature of TDD LTE mode, the TDD solution can also provide users with time-slot options, such as 1:3, 2:2, and 3:1, based on service characteristics.
The LTE-R system offers flexible network designs, such as dual-network and interleaved network layouts, and can also support active standby for all Baseband Unit (BBU) boards and active standby hardware for the Remote Radio Unit (RRU). ZTE's self-adaptive frequency compensation algorithm, based on scenario characteristics, ensures virtually no performance loss at speeds up to 300 km/h. ZTE's super-cell algorithm reduces the number of handovers between adjacent cells, guaranteeing quality of service. Cloud Radio, a ZTE-patented technology, reduces inter-cell interference and improves throughput.
ZTE adds advanced technologies and services that protect customer investments by designing LTE-R to absorb and incorporate GSM-R technology. The core network can easily switch from a 2G to a 4G wrapped packet core (EPC) network, as both share a hardware platform and service deployment. The radio access network meets the design requirements for the shared G/L platform and shared module. Based on the advanced and reliable SDR platform and Advanced Telecommunications Computing Architecture (ATCA), ZTE's new solution supports multi-layer backup mechanisms, such as network layer backup, data link layer backup, and top-layer backup. These technologies ensure high reliability for a single device and prevent single-point failures in the network, creating a reliable and seamless rail network.
