Link Wireless Camera System is New Equipment form New Manufactures

By Alexander Bogatkin, Maxim Fimstach, Anastasia Krasnova

Review contents:

Wireless Systems for Sound and Video Transfer from Camera Systems of Wireless Signal Transfer DynaPix Triad of DTC Communications Company Equipment of GMS Company Digital wireless system of receiving-transfer of sound and image signals of Grass Valley a Thomson Brand Company On-camera WRP20 System of IRTE Company (Italy) Wireless Transfer of Data from DY-DV5000 Camera with the Help of KA-DV 5000 Adapter Link Wireless Camera System is New Equipment form New Manufactures Swiss Wireless COFDM Systems Livetools in Russia Miniature Color Microdic Video Camera with Transceiver Wireless Systems of Video Transfer from Premiere Wireless Tandberg Wireless Operators’ Systems Reporter’s Radio Extender Teleview Reporter is Wireless Digital System of Video Signal Transfer “Camera-MTU” Transvideo wireless systems

Link Wireless Camera System (LWCS) of Link Research Company also represent the system of wireless transfer of video and sound and is one of the most popular products of this company. At first Link Research dealt with development of professional equipment in the sphere of digital television broadcasting since 2001. New products of the company presented on IBC 2001 became to be supplied to customers since October 2001 and became a direct reason of growth of busyness activity of Link Research in 2002. Among company’s customers are: BBC, BskyB, BT, CBC, ITN, and NTL.

LWCS, developed for covering of sports and news events, passed the new baptism of fire in Australia during recording by Channel 9 network TV channel of Rugby games of national league. This sports game is popular among Australian as soccer among Europeans.

First tests were conducted in three thousand audience, for their conduction double receiving system was used, which covered all its space with antennas situated in two different places on the sides of the field. That gave an opportunity for operators to move easily for covering of most interesting moments without a danger that wires might cross on the ground or worries about signal receiving by antennas. After the game with the help of LWCS were recorded interviews and quality of filmed material was so high that later it was give on the air for broadcasting. Use of such system overcame all expectations. Later it shown perfect faultless operative work during covering of 24-hour races Le-Mane (France) in 2002.

LWCS system in use

LWCS includes:

• build-in into the camera coder-transmitter (four models with different diapasons of signal frequencies: L1101 — 1,95…2,2 GHz; L1102 — 2,1…2,3 GHz; L1104 — 2,3…2,5 GHz; L1106 — 2,5…2,7 GHz);
• receiver: L3010 with elevating frequency reformer in diapasons from S to UHF and L2102 with minimal delay of signal receiving and also different model of demodulators (two-channeled L2002 and four-channeled L2004).

Main characteristics of LWCS are:

L1100 transmitter

• sizes of on-camera transmitter are 234×84×44 mm;
• weight is 1,05 kg;
• waterproof aluminum body;
• front rear side of transmitter has six 3 mm holes assigned for fastening to different types of batteries;
• temperature condition is -10…+70°C;
• power voltage is continuous, 10,5…14 V;
• consumed power is 18 Wt (depending on settings);
• SDI video entries with integrated sound;
• component digital entry 4:2:2 YCbCr;
• component analogous entry 526/625;
• positive video entry NTSC or PAL I;
• sound entries Audio1 and Audio 2: entry resistance is over 20 kOhm, one stereo couple or two mono channels;
• entry power of transmitter is 10…100 mW;
• modulation method is COFDM with choice of frequency band of 7, 8, and 9 MHz;
• MP@ML (4:0:0), 422P@ML (4:2:2) coding conditions.

Demodulator

Link XP of Link Research Company also represents a system of wireless video and sound transfer. In Link XP Link Research developers managed to combine two tasks: to provide news presentation of material (including an opportunity of qualified direct broadcasting) from wireless camera with smallest time delay of signal. Link XP product received Peter Wayne Award for “Best design and innovation” from international association of broadcasting equipment producers in 2002.

System’s remote control unit

During development of Link XP considered, that delay of signal coming through wireless system has to be so little in time that it was possible to operate with material filmed by wireless camera when combining it with usual material. For creation of Link XP specialists of the company applied technologies used during developing of other products, in particular, the base of new wireless system was L1000 coder. Models L1000 are used for coding/modulation in combination of news blocks and sports events. As a result of implementing of these technologies Link Research managed to create wireless transfer system with delay in one shot and qualified transmitting signal. Weight of the system is about 1.7 kg, consumed power is 18 Wt. The system is highly comfortable in use and virtually all parameters MPEG-2/DVB-T can be changed. CODFM modulation can be set in QPSK, 16 QAM, and 64 QAM conditions. Usually in majority of cases condition QPSK with FEC ½ and video flow of 5,7 Mbit/sec is used. Such “firm” condition is comfortable for providing of continuous signal transmitting. During covering of sports event it is more reasonable to use 16 QAM modulation condition, providing the flow of 11 Mbit/sec and continuous transfer almost the same as using QPSK. 64 QAM modulation condition is used rarely, it can be chosen for providing of qualified image but with significantly smaller viewing of space for filming. With different signal transfer the presence of two nearly situated receiving antennas is necessary what guarantees the receiving.

Simultaneous use of two LWCSsystems

Link XP also recommended itself on Le-Mane races.

In combination and characteristics Link XP system is in many things analogous to LWCS. The next improved model of wireless transfer system Link XP will be developed by Link Research together with Hitachi Denshi Europa. The new system will provide:

• full camera control;
• different receiving of signal;
• reversed video image in viewfinder window;
• compatibility with video equipment of other manufactures;
• video synchronization;
• elimination of delay (40 ms) of signal of the receiver.

Use of Link XP system in racing coverage

It is planned that in Link XP will be realized the opportunity of signal delivery of broadcasting quality in 4:2:2 format, system will have compact size and low power consumption. Link research hopes to present new two-directional Link XP on coming exhibition NAB 2003.

“Elogar” Company presented the material