Radio Access Network:Radio access for consists of a flatarchitecture in which the base stations, or eNodeBs, are connected directly tothe core network without the need for an intermediate radio network controller.The eNodeB contains Radio Frequency (RF) modules and a baseband processingmodule that has control and modem units. These can all be integrated into asingle cabinet.
Otherwise, the baseband unit and RF units, or remote radioheads (RRHs), can be deployed separately and linked by a cable. The RRHcontains the RF power amplifier and RF filter. To enable more flexible deployment options, basebandunits are located in station telecom rooms and RRHs are located in the outdoortrack area, for the current railway environment.
Upcoming Next generation radioaccess, offers further architecture flexibility by being able to take advantageof cloud technologies that offer enhanced reliability, flexibility, and easyscalability of capacity to meet actual demand. Radio functions can either be runin large centralized data centers or smaller distributed sites, or acombination of both with all components treated as a single cloud for easy and efficientmanagement.Due to its easier site acquisition, lowdeployment costs, and reduced site rentals, the mobile industry has adopted thedistributed base station architecture in the recent years. A distributedarchitecture also has the advantage of a better uplink (UL) budget because oflower RF cable losses.
Therefore, fewer sites would be needed compared to theintegrated cabinet option. While all railway operators can enjoy theseadvantages, the compact size of distributed deployments is particularlybeneficial for metro operators facing the challenge of deploying equipment inrestricted tunnel spaces that may not easily accommodate conventionalintegrated deployments. For metro railways, deployment of small cells can alsobe considered as they are generally easier to install in underground and otherlimited-space stations.Core Network:Core network solutions currently available aresuitable for a variety of network requirements – compact units to serve deployableand small networks, mid-sized core for full network deployments, and datacenter solutions for pan India networks. Further flexibility comes from virtualizationand cloud technology. Depending on the railway operator’s strategy,the core solution is constructed from various components: Compact Core, IMS,VoLTE/open TAS core, and HSS. Further enhancements are achieved by application serversthat provide railway-specific functionalities together with the missioncritical application server used in the public safety domain.
Solutions includeGroup Communication Server that is fully aligned with 3GPP.Backhaul Network:Backhaul network solutions with integratedpacket microwave and optical transport have shared services networkinfrastructure which can be deployed flexibly with no performance degradation.This helps meet diverse connectivity requirements and allows for future growth.Ready for software defined networks (SDN), they allow for future networkevolution.
In hybrid and commercial network deployments, these solutions supportQoS with prioritization of emergency calls and mission critical voice/ data overnon-mission critical and commercial voice/ data. The solutions also support policy management, trafficengineering, QoS-capable backhaul and radio networks, user differentiationbased on 3GPP standard QCIs, load balancing and admission control. Currentlyavailable backhaul solutions are complemented by comprehensive services tosimplify the evolution to high speed mission critical networks while assuringmission critical reliability and performance. Services include systemsintegration, network design and build, transformation consulting, managedservices and care.