The formulation of a test format to certify WirelessHD, a video transmission technology for home regarded as a wireless version of HDMI, has begun, but it turned out that a number of challenges need to be overcome before starting the test.
Challenges seem to be concentrated on tests concerning smart antennas used to realize stable transmission in particular. WirelessHD is a technology that transmits digital data of videos at 3 to 4 Gbps using the 60 GHz millimeter-wave wireless band.
In a lecture titled "Display Interface - the Latest Trend and Measurement Solutions" at CEATEC Japan 2007, Tetsuo Ogawa, ADSC senior application engineer for Technical Sales Support ADSC of Tektronix Japan Ltd., explained characteristics of the latest display interfaces and the trend in the development of specifications including WirelessHD. Nikkei Electronics has summarized the part concerning WirelessHD in the lecture below.
As HDMI, WirelessHD will be featured with TVs and other home appliances that general consumers use. For this reason, the specification must be authenticated through strict tests and it always must be made easy for anybody to connect compatible devices to each other.
Nevertheless, challenges that have not been taken seriously before arise one after another because WirelessHD uses millimeter-wave wireless communication technology, for which there has been no test format to certify the specification.
For example, it uses millimeter-wave, which has high directivity. Therefore, WirelssHD uses a smart antenna that has a capability of creating a bypass using reflected wave and other measures, when there is an obstacle in the pass between the transmitter and the receiver.
To certify other wireless communication technologies, tests have been conducted in a radio anechoic room, an environment with no radio reflections. However, no guideline has been indicated regarding in what surrounding environments standard tests should be conducted when testing technologies assuming such bypass use.
In addition, WirelessHD developers are also considering a specification that separately transmits video data and audio data to two different receiver devices. Tests in view of such use conditions have not been formulated, either.
As for the specification of WirelessHD technology, it will not be long before the initial specification is formulated. On the other hand, when it comes to the specification of the certificate test format for the technology, "I suppose it will take at least a year before it is formulated," said Ogawa.