The Gigabit Millimeter-wave Superhighway
The 60 GHz band is limited to short distance transmissions because of oxygen absorption in the atmosphere. This makes 60 GHz exciting for indoor, residential use, especially since low cost silicon CMOS devices are now available at such speeds. Innovation has recently sprouted with high speed mm-wave LANs, driven in particular by the desire to stream uncompressed high definition TV (HDTV) signals around a residence. Groups such as WirelessHD formed to exploit both the high data rate carrying capacity of the 60 GHz bands and the cost effective availability of chip sets. LG, Panasonic and Toshiba have all announced that they plan to ship commercial WirelessHD products in 2009. These will transmit uncompressed 1080p HDTV signals at 1.5 Gbps across a 10 m living room. Complex adaptive beam steering algorithms and phased-array antennas are employed to bounce signals off walls around obstructions such as moving persons blocking the main signal between transmitter and receiver. Line of sight transmission is a requirement for all mm-wave systems.
Battling for streaming wireless HD dominance in the living room is Wireless Home Digital Interface (WHDI), a technology physically similar to 5.8 GHz WiFi but specifically modified for video, audio and AV control. Although claims to the contrary, WHDI delivers only compressed HDTV with data rates to several hundred Mbps. However it is able to deliver this across a whole house rather than just a living room. Although later to emerge than WirelessHD, WHDI also has traction with big name consumer electronic vendors, and claims to have shipped over 100,000 chipsets in 2008. Dominance between WirelessHD and WHDI will not be determined by one technology being better than another. History has continually shown us that the technology that gains earliest traction with the consumer electronic vendors at acceptable consumer price points will dominate (For more information, read the July technical feature on Wireless HDTV).
With the availability of low cost chip sets at 60 GHz, there is much excitement for adoption of these bands for a wide array of high data rate consumer applications. The higher 70/80 GHz bands has almost global adoption of similar 70/80 GHz rules and regulations, verses a more fragmented availability of 60 GHz. Together with its higher data rate carrying potential, 70/80 GHz will continue to dominate industrial gigabit per second applications. In the longer terms, moves are already afoot to petition the FCC to open 50 GHz channels at 140 GHz and 240 GHz, opening the potential for 100-gigabit per second (100GbE) transmission speeds – truly opening the gigabit wireless superhighway.
If you are involved in the design or manufacturing of these types of components, please let us know what you are working on in the this area. Other questions and comments are also welcome.