Helios® Multi-Band Digital In-Train Repeater

For Multi-Band & Multi-Operator & Multi-Technology

Universal Multi-Band, Multi-Service, Software-Based In-Train Repeater Platform


Train applications present extremely challenging RF environments. The complexities of different terrain combined with the rapidly changing outdoor signal levels of the various networks makes it difficult for operators to provide the coverage and service their customers demand while travelling from city to city or to another country. But the business travelers expect good coverage, without dropped calls, and data connections wherever they are, for constant access to the internet, e-mail, and various mobile device applications.

In addition, with the development of mobile communication technology, new communication technologies have been adopted especially in 4G or even 5G NR. Hence, telecom operators must handle multiple technologies / networks simultaneously, which will cover most cellular frequency band such as 700MHz, 800MHz, 900MHz, 1800MHz, 2100MHz and 2600MHz etc., it will also call out a critical challenge that is generally space limit inside train carriage for the In-train repeater installation.

Providing reliable cellular services inside High-speed Trains is challenging in many respects. High-speed Trains travel through dense deployed cellular base stations along trackside requiring the Cellular Multi-Band & Multi-Operator In-Train Repeater to seamless roaming among these cellular base stations along the trackside and quickly synchronized with them. The Repeater equipment is subject to constant vibration conditions and occasional high shock levels. Also, the Donor Antenna, usually located on the roof the Train Carriage, must have sufficient Isolation from the Service Antenna to ensure that a Self-Oscillation condition is not initiated. Many new Rolling Stock are delivered with Built-In 19” Rack Space to house In-Train Repeaters.

For these reasons, Helios has developed our rack mount Digital Multi Band In-Train Repeaters to resolve these issues. It provides a fully Digital software-based platform and enables on-the-fly filter Re-Tuning at Boundary Borders.


  • Support up to four frequency bands in a standard 19” 4HU IP-65 rated stackable chassis within LTE BAND 1, 3, 7, 8, 20 and 28
  • Full digital software and hardware platform with Ultra-wide RF front-end design and enables multiple bands/technologies/operators
  • Innovative Digital Filtering technology basis on DSP and SDR to provide excellent signal selectivity and minimum time delay
  • Support multiple tunable sub-bands and multiple technologies
  • Support upgrading in case of frequency re-farming by software
  • Unique max AGC60dB firmware to ensure stables operating on moving platforms such as ship or trains
  • Automatic Frequency & Bandwidth Reconfiguration based on Geofencing & positioning via option embedded GPS receiver
  • Automatically switch off repeater in case of too close to the BTS by built-in RS-AGC algorithm or option GPS positioning
  • High working gain as Min. 80dB.
  • Downlink RF Output power +23dBm per BAND and Uplink RF Output power +30dBm per BAND
  • RJ-45 Port as LAN port to support IP Web Browser GUI for Local Control
  • Additional RJ-45 Port as WAN port to support remotely access through Internet/Intranet/VPN
  • Support remote monitoring by SMS or Data Link via built-in 2G/3G/4G Cellular Modem (Option)
  • Details repeater parameters and status can be monitoring by built-in WEB GUI, such as RSSI, temperature, output power level, gain, ATT, VSWR, PA state etc.
  • iBwave VEX component files are available for your in-building wireless and fiber network design and deployment projects
  • SNMP V2 & V3 support with a MIB File

System Diagram

Technical Specifications

ItemsHelios® Digital Multi-Band In-Train Repeater
Frequency (Customized)800MHz & 900MHz & 1800MHz & 2100MHz & 2600MHz
Filter Design4 * (0.6~10MHz) + 4 * (0.2~5MHz)@ 800MHz, 4 * (0.6~10MHz) + 4 * (0.2~5MHz)@900MHz, 2 * (0.2~5MHz) + 2 * (0.6~10MHz) + 1 * (0.6~20MHz) + 2 * (0.2~20MHz) + 1 * (0.2~15MHz) + 1 * (0.2~10MHz) @ 1800MHz, 4 * (0.2~20MHz) + 2 * (0.2~15MHz) + 2 * (0.2~10MHz) @ 2100MHz, 4 * (0.2~20MHz) + 2 * (0.2~15MHz) + 2 * (0.2~10MHz) @ 2600MHz (Customized)
Instantaneous Bandwidth (IBW)Max 30MHz @ 800MHz, Max 35MHz @ 900MHz, Max 75MHz @ 1800MHz, Max 60MHz @ 2100MHz, Max 70MHz @ 2600MHz
Auto Frequency & Bandwidth ReconfigurationBased on Geofencing & positioning via option embedded GPS receiver
RF Composite Output PowerDL: 23±2dBm per BAND
UL: 30±2dBm per BAND
GainMin. 80dB (+/- 2dB)
AGC Control RangeMin. 40dB
Noise FigureTypical 8dB @ Max Gain
Local ControlIP Web Browser GUI via RJ-45 Port
I/O Impedance50 ohm
IP RatingIP-65
MTBFMin. 100,000 Hours
Power SupplyDC-24V or AC220V (+/-15%), 50Hz (Customized)
Dimension19" 4HU Depth 447mm Rack-mounted
WeightMax. 35Kgs
Standard ConformanceEN 301 908-11, EN 301 908-15, EN 303 609, EN 50155, EN 45545-2, EN 50121, EN 60529