The arrival of 4G LTE is an important development for the rail industry because it answers the challenges and allows the consolidation of multiple radio systems into one unified ground-to-train communication solution. LTE — a commercial off-the-shelf technology — presents several key advantages for the transportation industry. The primary characteristics of LTE – namely high speed, high security, and high bandwidth capacity – allow it to carry voice and data for train control, on-board video surveillance, and infotainment services for passengers – all on a single IP network and all at the same time. LTE has low latency (down to 10 ms), meaning it can support highly time-sensitive applications and provide high levels of QoS7 management. It can be deployed in many different frequency bands and has multiple features related to encryption and authentication, rendering this technology secure by default.
The Nokia LTE Ground-to-Train for Railways solution is composed of a core network: Evolved Packet Core (EPC) and an access radio network UMTS Terrestrial Radio Access Network (E-UTRAN). EPC is a native «all-IP» based and multi-access network that enables the deployment and operation of a common network for every kind of 3GPP access network (2G, 3G and LTE), and even non 3GPP (WLAN). E-UTRAN LTE is connected to the EPC core network in packet mode.
E-UTRAN is composed of eNodeB (LTE base stations)
- EPC is composed of a service gateway (SGW), packet gateway (PGW), mobility manager (MME), policy and charging rules function (PCRF), home subscriber server (HSS) and IP multimedia subsystem (IMS).