Broadcast Video Wireless - How to Choose the Right Technology - Part #2 - VidOvation Corporation
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Broadcast Video Wireless – How to Choose the Right Technology…

The Wireless Video Transmission Broadcast Guide covers:

Selection Criteria Supported Bit Rates Link Distance Video Interfaces Video Formats and Compression Initial and Recurring Costs License vs. Unlicensed Spectrum Portability Antenna Types Wireless Applications Sports News Gathering Grab-and-Go Anywhere Camera’s Television and Film Production Confidence Monitoring Video Assist and On-set Monitoring Wireless Technologies Traditional Private Microwave Unlicensed Wi-Fi 4G LTE/Bonded Cellular 60 GHz Uncompressed HDMI & HD SDI

Summary: New technologies have greatly expanded the number of choices available to broadcasters for transporting live video from venues to studios. For example, cell-phone circuit bonding has now made it possible to transmit live video from anywhere that has good cellular coverage. Recent advances in Wi-Fi standards have increased the bitrates available for transporting video in local areas. Today, even uncompressed HD video can now be transported wirelessly using 1.5 Gigabit radio links operating at 60 GHz. Each technology has benefits and drawbacks, relative to specific applications and user environments.

Wireless video transport has been a key part of television broadcasting since the rst over-the-air transmission tests were performed almost a century ago. The methods used to transport video signals from one location to another have continued to push the limits of each new technology that has come along, including coaxial cable, microwave, satellite, ber optics and cellular radios. With high bandwidth signals, demanding QoS (Quality of Service) requirements and sensitivity to excessive delay, video has often been at the leading (or bleeding) edge of the capabilities of many technologies.

Building on these past successes, television broadcasters today have an enormous range of wireless video transport options. These range from dedicated links that support 1.5 Gbps uncompressed HD video to highly compressed video streams that run over Wi-Fi infrastructure. In between are devices and systems to t virtually every application. With so many choices, it can be difficult to select a suitable product that offers the best combination of performance and reliability at a price point that makes sense for each project.

Modern modulation technologies can pack more bits into a given amount of channel bandwidth. Changing from a modulation technique that uses two bits per symbol (such as QPSK) to one that uses four bits per symbol (such as 16QAM) will double the bit rate on a wireless link without changing the channel bandwidth. There is, of course, a cost in doing this, with more processing power needed on both ends of the connection to generate and detect these more complex signals. Plus, there is another penalty associated with the more complex modulation schemes: they are more sensitive to noise and interference. This is why Wi-Fi signals, among others, will automatically adjust their modulation (and consequently bit rate) between more simple and more complex schemes to adapt to changing RF channel conditions.

Excerpt from 60GHz Section: New high-speed semiconductor technology has enabled the development of affordable, compact wireless systems that can operate in the unlicensed 60 GHz frequency range. 60 GHz systems on the market today are completely uncompressed HD-SDI operation at 1.5 Gbps, including any embedded audio channels, metadata, SMPTE time code, etc. Because the signals are uncompressed, no encoding/decoding delay is present in the system, making it ideal for sports, live interviews and other time-sensitive applications. Solutions are also available in the 70/80 GHz and the 90 GHz frequency bands, including high speed Ethernet links that can support bi-direction GigE speeds, which is great for high performance IP video and audio networking. Signals operating at these very high frequencies

Example Specifications: Fixed Portable Unlicensed Bonded 60 GHz COFDM Microwave Microwave Wi-Fi Cellular HDMI HD SDI Transmitters Receivers Uncompressed Bit Rates 20-50 Mbps 5-50 Mbps 5-200 Mbps 1-20 Mbps 1.5 Gbps Link Distance 1-50 km 1-10 km 0.1-5 km N/A 300-500m Video Interfaces ASI, SDI, HD-SDI ASI, SDI, HD-SDI SDI, HD-SDI, IP SDI, HD-SDI HD-SDI Video Compression Antenna Types Parabolic Parabolic Omni or Dish Omni (typical) Parabolic