Professional and wireless cameras
broadcast are one of the great novelties in the area of technology and
video streaming. To achieve with them multiple applications, everything that
it is necessary to place a transmitter and antenna at the exit of the camera and a
antenna with receiver at the site where it is required to monitor or retransmit the
signal.
Until the beginning of the twenty-first century, wireless signal transmission
of the camera was only achieved using microwaves with analog technology in
FM. In 2001, the manufacturer Broadcast Microwave Services, BMS, launched the market
COFDM digital technology products for wireless cameras, which
make them a pioneer of this technology. Carry Coder, Truck Coder products
and Heli Coder, all Generation I, were introduced during NAB and started
thus its commercialization in the television market.
The output power of up to 1 watt of the Carry Coder I, and 10 watts both
of the Truck Coder I and the Heli Coder I, it continues to be the largest
of the market and is decisive for its great reliability and signal range.
The magic of COFDM digital technology in microwave propagation,
combined with this BMS transmitter output power level of up to 1
watt, allows to reach distances of up to one mile in urban environments, without
line of sight between the camera transmitter and the receiver. Antennas
used in both equipment are omnidirectional of 2 dBi gain, which
additionally it allows a total mobility of both equipment.
For longer distances it is required to have a line of sight between the transmitter and
the receiver, but there is always the advantage that the reflections that can
existing in the link will contribute to a better reception of the signal, eliminated
the traditional problem of ghosting and fading.
At NAB 2004, BMS launched the Generation II Coder family, which maintains the
same power levels and manages to optimize certain parameters of the signal of
MPEG2 video, such as both 4:2:0 and 4:2:2 compression and the low delay figure.
The use of COFDM digital technology facilitates the mobility of a
camera during the transmission of live video images, with the use
of omnidirectional antennas at both ends on short-range links (20
miles).
Wireless camera applications with medium-range links (50
miles) require an omnidirectional transmitting antenna on the camera and
directional at the image reception site. BMS achieves, through a
automatic GPS tracking, motion camera reception apps
in ships, planes, helicopters and even land mobile units.
On the other hand, the use of wireless cameras in long-range links
(100 miles), not only will it depend on the power of the transmitter, the direction of
the antennas and the tracking system, but also the curvature of the Earth
develops a decisive role in the reception, so they must be taken
forecasts such as placing the receiving antenna as high as possible from a
tower and preferably said tower on the top of a mountain that allows
line of sight at all times with the mobile camera that transmits the signal.
BMS microwave systems are coupled and also transmit signals from
cameras with Night Vision, thermoimages and infrared. Many of these
Applications are currently used by the air force and police in
several Latin American countries.
Watch interviews in a stadium dressing room, shot details and angles of
live plays at a baseball, football or basketball game, perhaps power
have access to places where the news originates with a cameraman in a
urban center or public institution, as well as the use of a helicopter of
news on a highway or event site, or
police and military use in the persecution or monitoring of a region, constitute
the most common applications of wireless cameras, where the signal
received live is decisive to gain audience, obtain information to the
moment and make immediate decisions at a distance.
Leave your comment