Mission-Critical Communications for Rail & Tunnel Environments
Millions of passengers travel through rail, subway and highway tunnels every day. Transit operators, maintenance teams and public safety agencies all depend on seamless, reliable radio coverage to maintain operations and ensure a safe environment.
Tunnel environments present unique challenges for distributed antenna system (DAS) deployments, including long distances, high optical link budgets, legacy or lossy radiating cable, limited fiber availability, multiband requirements and the number of remote units needed across the network.
Avari Wireless provides a high-performance digital DAS platform designed to support mission-critical communications in complex tunnel environments. The system can support a broad range of technologies and frequency bands, including GSM-R, FRMCS, TETRA, VHF, UHF, 700 MHz, 800 MHz, LTE and 5G, enabling rail operators and public safety agencies to use a common, scalable infrastructure for both existing and emerging communications requirements.
Designed for Long Tunnel Environments
Tunnel networks can span several miles, with remote units separated by significant distances. Avari’s digital transport architecture provides an industry-leading optical link budget, enabling signals to be distributed over long fiber distances while maintaining consistent performance.
Avari also incorporates Automatic Optical Delay Compensation, which measures the signal arrival time to each remote unit and automatically balances the network to synchronize the antenna system. This helps minimize time-delay interference (TDI), an important consideration for narrowband radio systems as well as LTE and 5G applications.
Flexible Fiber Architecture
Limited fiber availability is a common challenge in subway and rail systems, particularly when redundant headend locations are positioned at opposite ends of a tunnel or rail line.
Avari supports flexible star, daisy-chain and ring fiber architectures, giving network designers greater flexibility when working with existing fiber infrastructure while maintaining redundancy and system resilience.
Mission-Critical Rail and Public Safety Coverage
Avari’s high-reliability DAS platform provides a flexible network infrastructure capable of supporting multiple radio technologies and frequency bands across a single distributed system.
For rail applications, the platform can support technologies including GSM-R, FRMCS, TETRA, LTE and 5G, helping operators transition from legacy railway communications systems toward next-generation mission-critical networks.
For public safety applications, Avari supports VHF, UHF, 700 MHz, 800 MHz and other LMR frequency bands, enabling reliable first-responder communications throughout tunnels, stations and other challenging indoor environments.
The scalable architecture also allows additional technologies and frequency bands to be incorporated as network requirements evolve.
Built-In Redundancy and Self-Healing
Mission-critical communications demand high system availability. Avari supports end-to-end redundant configurations, including fiber diversity, redundant headend radio sources and automatic switchover.
Intelligent system algorithms can adapt, reroute channel traffic and reconfigure signal paths based on fault conditions, helping the network maintain coverage and recover automatically without manual intervention.
Centralized Network Management
The Avari VL Element Manager (VL-EM™) provides centralized monitoring and management across the entire distributed antenna network.
The platform supports fault, performance and configuration management, along with industry-standard Simple Network Management Protocol (SNMP) for integration with third-party network management systems.
Public Safety Alarm Integration
For public safety deployments, Avari digital DAS network elements support dry-contact alarm connections for both radio communications systems and battery backup units in accordance with applicable fire-code requirements.
Avari's flexible alarm architecture supports both centralized and distributed fire alarm panel configurations, giving system designers greater flexibility when integrating DAS infrastructure into complex facilities.
