Contact-Docsis Digital radio relay station
* It is intended for arrangement of a remote CATV network
with a CMTS (for example, Motorola BSR-1000,
BSR-2000), delivering Internet to the subscribers of
cable networks and operating in the DOCSIS** standard
* Communication arrangement is effected according to the
* Plug-in design
| Forward channel transmission signal frequency
|| 11,605 GHz
| Reverse channel transmission signal frequency
|| 11,075 GHz
| Forward channel transmission output power not less/Modulation kind in forward channel
|| 2 mW / QAM64
| Data transmission rate in forward channel
|| 25 Mbit/s
| Reverse channel transmission output power not less/Modulation kind in reverse channel
|| 10 mW / QPSK
| Data transmission rate in reverse channel
|| ~3.4 Mbit/s
| Out-of-band and side emission level
|| -50 dB
| Guaranteed operation distance when using combined paraboloid antennas of 1,2m diameter
|| ≥ 20 km
| Forward channel IF frequency
|| 1855 MHz
| Reverse channel IF frequency
|| 1325 MHz
Radio relay station "Contact-DOCSIS" operation is seen from the structure scheme specified in the picture.
*CMTS (Cable Modem Termination System) is a head cable modem.
** The DOCSIS standard (Data Over Cable Service Interface Specification) presupposes data transmission over a CATV network to a subscriber with the maximum rate of not less than 42 Mbit/s (while using of a 256 QAM multiposition amplitude modulation) and data reception from the subscriber with the maximum rate of 5,12 Mbit/s and use of a QPSK modulation.
Worsening of "Contact-Docsis" SNR in a forward channel of ~4dB (37dB instead of 41dB for QAM 256; 41dB - SNR with the system "CMTS head modem-subscriber modem").