Autonomous Driverless Train Systems

One APN connection, with the associated IP address, means that the public, private and critical network data flows over a single IP connection.

Multiple PDN’s allow for enhanced network security as they are explicitly designed to separate public, private, or critical data over multiple connections, with each PDN having a unique IP Address.

Each PDN is configured independently by the 4G-LTE network. For example, allocate the first PDN for private communication network data and the second for critical train control systems.

Traditional 4G networks offer best-effort IP connectivity for voice, video, and other real-time critical application data.

Railway 4G networks need to distinguish different kinds of traffic, thereby ensuring the performance of critical applications, guaranteeing enough bandwidth for their correct operation.

Dedicated bearers provide dedicated tunnels to one or more specific traffic and include quality-of-service (QoS) for particular service flows.

The router can establish dedicated bearers, based on quality-of-service (QoS) requirements. Total of 11 dedicates bearers can be supported simultaneously per PDN.

GBR resource type means the bandwidth of the bearer is guaranteed. For instance, critical network communication and voice traffic could be assigned a guaranteed bit rate.

Having a non-GBR resource type means that the bearer is a best effort type bearer and its bandwidth is not guaranteed. Security CCTV and non-essential communication cloud be assigned with no bandwidth guarantee.

A failed router in the network can cause loss of service to data and train control systems. Therefore, it is critical for the network to implement redundancy in the network and the onboard systems so that a loss of a link or node does not result in loss of service.

All onboard communication hardware has active and standby 4G interfaces. If the active link fails, the standby can take over with limited packet drops in the network. Both links can be configured to load-balance increasing network access capacity.

Mobile Router Multipath (MRM) support has increasingly become important because railway and public transportation are likely to adopt multiple wireless technologies to support their mission-critical applications.

Support for multiple paths, and thus numerous wireless technologies, between the railway router and automatic train control (ATC) system and allows traffic to be load-balanced over all available interfaces.

When there are multiple paths, the traffic from the mobile networks that goes toward the router is generally load-balanced. Policy-based application routing allows you to identify a particular type of traffic from the mobile networks and then select the tunnel for routing this traffic.