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Wireless uncompressed HDTV, which is often referred to "Wireless HDMI," will change the way video displays are connected to video sources.
In the past 10 years, many companies have been trying to solve the problem of wireless video connectivity with very limited success, mainly because the solutions could support only delivery of compressed video, which is typically not available at the output of most video sources.
The consumer electronics industry has come to realize that a wireless uncompressed video link is needed in order to provide a universal wireless HDTV interface.
A few upcoming startups have accepted the challenge of delivering the huge amounts of video data wirelessly (up to 3Gbps in 1080p) using very different approaches.
These include: WHDI technology in the 5GHz unlicensed band; Approaches based on an extended version of Ultra-Wide Band (UWB); A combination of compression and UWB: and; 60GHz spectrum solutions. This article will describe these options.
Wireless HDTV
Wireless HDTV continues to be a hot topic in the consumer electronics world. Flat- panel TVs offer consumers new placement opportunities that were not possible with the old bulky CRT TVs.
TVs can be hung on the wall, under the cabinet in the kitchen and in other in tight spaces.
In practice, the cumbersome audio/video wires limit where these TVs can be placed. Consumers have indicated in surveys that they would like to hang their new flat panel TVs on the wall, and yet most of them don't because of installation difficulties: namely the pain of running the audio/video wires to the display.
Posing even greater installation difficulties are consumer multimedia projectors.
Although quality is getting better and prices are dropping, the market has yet to take off. The main reason is the difficulty of running wires from video sources to the projector.
Wireless video will change all of this. It will facilitate installation of wall-hanging TV displays and projectors, and will make customers happy, which in turn will make manufacturers of wireless TVs and projectors happy.
Compressed vs. uncompressed
It is not surprising that TV and projector manufacturers have been struggling for several years to find a solution for a wireless video connection to displays. The success of 802.11 raised expectations that it could also solve the problem of wireless video.
The wide support for the emerging UWB standard also created expectations that the long-lasting wireless video problem would soon be solved by this new high-rate wireless modem technology.
However, these expectations have yet to be realized, as they are all based on one wrong assumption: that the video that needs to be delivered wirelessly is in compressed format.
Although typically distributed in compressed format HDTV content is rarely provided in compressed format at the output of most video sources.
CE manufacturers and semiconductor vendors in this market have come to realize that the only way to provide a universal wireless link to displays is to provide a wireless uncompressed HDTV link between sources to displays.
Approaches to wireless, uncompressed HDTV
The problem is that delivering uncompressed HDTV wirelessly is very difficult. Rates can be as high as 3Gbps for 1080p and 1.3-1.5Gbps for 720p and 1080i. Thus, both 802.11n and UWB fall far short of delivering these very high rates.
Several startups have taken the challenge of achieving the ambitious goal of delivering uncompressed HDTV, with first products in the market expected in 2007. Solutions include: a WHDI video-modem solution in the 5GHz unlicensed band; a proprietary/extended UWB approach; a UWB and compression combination; and, 60GHz-based solutions.
The advantages and disadvantages of the various solutions will be discussed in the remainder of this article.
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