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Advantages of RADIUS CTR.GSM900

RADIUSRADIUS system is designed to provide GSM 900 mobile network coverage (supports HSCSD, GPRS, EDGE) for remote rural areas, roads and railways where the installation of common GSM base transceiver stations is not economically feasible due to small mobile traffic.

The system is comprised of a number of units including capacity transfer radios (CTR) which retransmit radio signal sequentially from a base station to users' mobile terminals, and provide network coverage over an area.

The system is to be connected to the equipment of a common GSM-site (compatible with the equipment of any vendor), and designed to retransmit and distribute up to 6 GSM carriers of a base station (from 1 to 3 hops without installation of radio relay systems) over a target territory.

System benefits

  • Significant reduction of CAPEX and OPEX costs (comparing to the use of traditional base stations) for GSM coverage over a specific territory
  • Reduction of power consumption of a site from 1.5—2 kW (for a traditional equipment) down to 0.36 kW with the same coverage area and network capacity
  • Increase of the length of a GSM connection zone of one base station equipped with the system by 4—6 times
  • Reduction of costs of mobile operators due to simultaneous operation of the system by 2 operators (RAN-sharing) without loss in quality of services and network coverage over a target territory.

Main components of the system

  1. Converter unit (CNV) is designed to convert BTS GSM carriers (from 1 to 6) to retransmission bandwidth
  2. Capacity transfer radio (CTR1) is an intermediate unit with two-way duplex retransmission
  3. Capacity transfer radio (CTR1) is an end unit with one-way duplex retransmission

The system is designed for operation in GSM 900 mobile networks and provides two-way serial retransmission of BTS signals — up to 6 carries via the CNV and CTR units to subscribers’ mobile stations (MS). The system provides Tx/Rx modes for GSM signals by mobile station in a retransmission zone.

Advantages of RADIUS CTR.GSM900

  • replaces BTS, radio relay system, and BTS power supply subsystem
  • compatible with BTS of any vendor (Ericsson, Nokia, Huawei, and others)
  • no need to update system software when BTS’ software is updated

Operation principle

CNV is mounted at the site of a BTS. The unit converts GSM carrier frequencies of BTS (separate sectors of BTS) to retransmission bandwidth, and then transmits them to a remote area.

CTR1 at the remote area receives, amplifies, and retransmits the received signal further along the link, as well as converts two signals back to GSM bandwidth providing a coverage of 2 sectors similar to a BTS (one GSM carrier in each sector). CTR2 end unit receives and amplifies the signal received from CTR1 and down converts them to two GSM signals providing two sectors of coverage. The schematic diagram of the system configuration is shown in Figure 1 (3 retransmission sectors with GSM carriers).

Figure 1


Operating frequency:
— GSM channel UL 880—915 MHz
DL 925—960 MHz
— retransmission channel 5925—6425 MHz
TRX output power:
— GSM channel (per carrier) up to 40 dBm (adjustable)
— retransmission channel (total) up to 27 dBm (adjustable)
Number of retransmitted GSM carriers up to 6
Number of GSM transceivers per CTR 2
Number of inputs/output in CNV for connection of GSM carriers from BTS 1 Rx port and 1 Tx port (up to 6 carriers to 1 port) 
Number of hops up to 3
Signal delay per unit less 5.5 µsec
Operating temperature minus 40…+55 °С
Power consumption (at output powers of 40 dBm) less 360 W (CTR1)
less 250 W (CTR2)
less 100 W (CNV)
Housing protection rating IP67
Overall dimensions 520х400х260 mm (CTR)
320х400х260 mm (CNV)
Power supply ~220/110 (CTR)
minus 48 (CNV)
Weight ≤ 47 kg (CTR1)
≤ 42 kg (CTR2)
≤ 35 kg (CNV)
Antenna connectors — DIN 7/16 socket (GSM channel)
— N-type socket (retransmission channel)
Connectors for Rx, Tx connection of CNV GSM channel to BTS N-type socket
Compliance to international standards TS 145 005 v13.3.3.0 (2017-01)
ITU-R F.383-8
Local / remote control  — LAN local control (Ethernet, Wi-Fi)
— remote control via built-in modem (GSM/UMTS)
Management system CTR, CNV units are managed with the help of CTR Management System (CMS)
CMS functions — remote control of settings including increase/decrease of output power of channels, carrier frequency of retransmission channel, GSM channel number, etc.
— remote monitoring of output/input power of retransmission and GSM channels, UL/DL amplification, channel frequency spectra, and other statuses of the units

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