UWDS Multimedia Head-End

* A multimedia head-end operating in the frequency range of 10,15 - 10,3 GHz, 10,5 - 10,65GHz, 11,7 - 12,5 GHz is intended for   arrangement of digital TV broadcasting, providing subscribers with a high-quality over-the-air Internet and IP telephony (in coverage   area radius 20...40 km and subscribers quantity to 2000).
* It is manufactured in four versions: UWDS 10/12M, UWDS-12M, UWDS-10M, UWDS 10/12M (see table 1).
* The manufacturer of these products is "Topaz" OJSC, Donetsk (tel.: 8-0622-53-13-42, fax: 8-0622-53-68-67,
  e-mail: postmaster@topaz.donbass.com)

An UWDS-10M head-end provides high-density data transmission form 4 to 5 bit/s/Hz in comparison to an UWDS 9/10M, an UWDS 10/12M and an UWDS-12M having the data transmission density of about 2 bit/s/Hz. The abbreviation 10М, 9/12М, 10/12М, 12М corresponds to operating frequency range of the head-ends of 10GHz, 9-12GHz, 10-12GHz, 12 GHz respectively.

The appearance of the UWDS-12M, the UWDS-9/12M and the UWDS-10/12M is analogous to the UWDS-10M appearance. The difference is in the unit change from the CON-100 production line to the CON-200 production line (correspondently A/D, D/D, R/D) shaping signal with a QPSK modulation on the IF frequency (as a result there are no MCD-110/4-19'' units in the head-ends UWDS-12M and UWDS-10/12M). Television and Internet transmitters are also constructed for their range. Subscriber sets are manufactured using two antennas. A tuner SRD-200M is used for digital TV reception (a CRD-200M in the UWDS-10M).

The coding system used in the UWDS head-ends is intended for operation not only with the subscriber receivers SRD-200M and CRD-200M having no card bin (it increases cryptographic robustness) bit also with receivers produced by other manufacturers supplied with card bins. Currently the system is tested on Samsung (DTB 94012, DCB 9401V), Openbox (X-800) and Startrack receivers. The company sells SMART-cards to accompany the receivers and a programmer with the help of which an operator carries out a presale installation. The system is registered by a consortium DVB Project and has an ID 0x4AF7 (www.dvb.org).

Let us consider application of a subscriber set for TV+Internet with use of 2 antennas for different systems: UWDS-9/12M, UWDS-10M, UWDS-10/12M and UWDS-12M.

A standard satellite head with a heterodyne oscillator frequency of 10,6GHz is used for digital TV and Internet transmission (of a forward channel) for the UWDS-9/12M. The satellite head needs some overpatching. Critical wave length for waveguides with a circular section is deducted from the expression ?cr =3,41R, where R is the waveguide radius amounting to 8,75mm in a satellite converter. Thus the critical length for the waveguide is the frequency of 10,067GHz. As far as data transmission is effected in the frequency range of 9,8-9,9GHz dielectric loading of the waveguide with ПС1-200/PS1-200 material with the dielectric constant e=1,3 (plastic foam) was effected to use the waveguide in the frequency range without a labour-intensive mechanical overpatching. Waveguide dielectric loading of the waveguide with plastic foam enabled providing the waveguide operating frequency range from 9,8 to 12,2 GHz. A bandpass filter was excluded from the standard satellite converter board (its operating range was 10,7-12,5GHz) in addition of the waveguide overpatching. An IF amplifier output stage was excluded to avoid overloading of the receiving converter with reverse channel transmitter signal. Internet transmission is effected by a separate transmitter constructed in the case of a standard satellite converter the waveguide of which has also dielectric loading (heterodyne oscillator frequency is fhet=10,022GHz).

A standard satellite head with a heterodyne oscillator frequency of 9,790GHz is used for digital TV and Internet transmission (of a forward channel) for the UWDS-10M. It is achieved by the second heterodyne oscillator frequency adjustment (by a plunger piston) (the standard frequency of the first heterodyne oscillator is 10,6GHz, the standard frequency of the second heterodyne oscillator is 9,750GHz). Internet reverse channel transmission is effected by a separate transmitter with a separate antenna (heterodyne oscillator frequency is 10,2525 GHz).

A standard satellite head with a heterodyne oscillator frequency of 10,4GHz is used for digital TV and Internet transmission (of a forward channel) for the UWDS-10/12M. It is achieved by replacement of a dielectric resonator in the first heterodyne oscillator (the standard frequency of the first heterodyne oscillator is 10,6GHz, the standard frequency of the second heterodyne oscillator is 9,750GHz). A reverse channel transmitter is used for Internet reverse channel transmission. The transmitter is analogous to the reverse channel transmitter used in the UWDS-10M.

A standard satellite head with a heterodyne oscillator frequency of 10,876GHz is used for digital TV and Internet transmission (of a forward channel) for the UWDS-12M. It is achieved by the first heterodyne oscillator frequency adjustment (by a plunger piston) (the standard frequency of the first heterodyne oscillator is 10,6GHz, the standard frequency of the second heterodyne oscillator is 9,750GHz). A reverse channel transmitter is used for Internet reverse channel transmission. The transmitter is analogous to the reverse channel transmitter used in the UWDS-10M but with a heterodyne oscillator frequency of 12,46GHz.

Thus all the four systems (UWDS-10M, UWDS-9/12M, UWDS-10/12M, UWDS-12M) have very similar subscriber sets. Reference frequency stability for digital TV and Internet reception is +500kHz, operating temperature range is -30...+50^оС. Reference frequency stability for Internet reverse channel transmission in the operating temperature range is ±20kHz.

• UWDS Multimedia Head-End
• UWDS 9/12M Multimedia Head-End
• UWDS 10/12M Multimedia Head-End
• UWDS 12M Multimedia Head-End
• UWDS 10M Multimedia Head-End
• TV transmission:
  6.1-6.5 GHz
  RASTR System
• DVB-C Subscriber signal receiver for RASTR-15 system (6,17-6,425 GHz)
• DOCSIS subscriber signal transmitter 10,2105-10,2945 GHz