In preparation for a new generation of 4K Ultra HDTVs, the HDMI forum today announced its first major upgrade to the popular audio/video interface since version 1.4 was released four years ago.

With up to 18Gbps throughput, HDMI 2.0 can support 3840 x 2160 resolution video at up to 60 frames per second (fps), which is four times the clarity of today's 1080pm video resolution. The new specification, the first to be developed by the HDMI Forum, also offers up to 32 uncompressed digital audio channels (1.4 supports eight channels), as well as dynamic auto lip-sync and extensions to the Consumer Electronics Control (CEC) connection.

The HDMI 2.0 connector and cable are unchanged from the previous 1.4 specification and is backward compatible for audio/visual equipment supporting that previous iteration.

Version 2.0 of the HDMI specification does not define new cables or new connectors. Current high speed cables (category 2 cables) are capable of carrying the increased bandwidth. The HDMI 2.0 Compliance Test Specification (CTS) is expected to be released before the end of 2013.

The HDMI Forum, which consists of 88 member companies, could not say when HDMI 2.0 compatible products would be available. When the previous version, HDMI 1.4, was released in May 2009, the first television and audio products with the new interface became available in the second half of that year.

"The introduction of the HDMI 2.0 Specification represents a major milestone for the HDMI Forum. Our members collaborated closely to take the highly successful HDMI Specification to the next level by expanding audio and video features for consumer electronics applications," Robert Blanchard, president of the HDMI Forum, said in a statement.

Ultra High Definition TV technology offers resolution measuring 3840 x 2160 pixels, or 8 megapixels -- four times that of 1080p televisions, which offer 2 megapixels of resolution. Besides far higher resolution, one advantage pointed out by industry pundits is that 4K TV can show passive 3D better than today's 1080p sets.

Earlier this year, the world's third-largest television maker, China-based TCL, announced that it will sell a 4K resolution, 50-in. ultra high definition (UHD) TV starting this fall for $999.

The complete Version 2.0 of the HDMI Specification is available to equipment makers on the HDMI Adopter Extranet.

HDMI Licensing, LLC will hold a press conference to discuss the new features of the HDMI 2.0 Specification at the IFA 2013 consumer electronics show in Berlin on Friday at the TecWatch Forum.