Version 1.0 of the Wireless Home Digital Interface (WHDI) specification announced today is expected to compete with WiFi for shuttling HDTV around the home. WHDI is backed by chipmaker Amimon, Motorola, Sony, LG, Samsung and Sharp. The first WHDI standard based products are targeted to be available to consumers in Q3 of 2010.
HDMI cables currently connect computers and Blue Ray players with televisions. Cables deliver uncompressed HDTV. Amimon hopes to replace HDMI cables with the new Wireless Home Digital Interface spec.
But why would consumers want to create an incompatible 5 GHz wireless HD network in their home? WHDI says Wi-Fi cannot send uncompressed HD video. That requires gigabit speeds and WiFi tops out at 100-600 Mbps. The 802.11ac standard may help in a couple of years. It will upgrade 802.11a to use 80MHz or even 160MHz channels for near Gbps speed.
Currently WiFi must use compressed HDTV which only requires 20 Mbit/s in the case of MPEG-2 compression and 12 Mbit/s for MPEG-4 compression. In order to superimpose information over video, an uncompressed channel is required. WHDI says their system has less latency and is more cost/effective than WiFi for connecting high definition televisions.
WHDI claims speeds that are “equivalent” up to 3 Gbit/s (including 1080p/60Hz), using a 40MHz channel in the 5GHz unlicensed band. What “equivalent” means is anyone’s guess. Instead of compression, WHDI’s secret sauce prioritizes the most visually significant bits of a video stream. It relegates any glitches to the parts of the picture that aren’t changing. WHDI uses HDCP revision 2.0 to provide Hollywood-approved digital content protection.
By using 5GHz spectrum, as opposed to the 60GHz range, “The performance is similar to WiFi: 100-plus feet through walls,” says Leslie Chard, vice president of marketing for Amimon and president of WHDI LLC, the Amimon subsidiary in charge of licensing the standard. Eventually, says Aminon, one 5GHz chip will handle both WHDI and WiFi, letting equipment use whichever standard is appropriate for a given task.
At least five major wireless standards are competing for Gbps home networking:
- WirelessHD at 60 GHz: Using the unlicensed 60GHz radio frequency band, WirelessHD can use 7GHz of continuous bandwidth to send uncompressed HD video. The 60 GHz band does not go through walls and usually requires line of sight between transmitter and receiver. The WirelessHD specification uses of beam forming to increase the signal’s effective radiated power.
- Wireless Gigabit Alliance at 60 GHz: WiGig is a different specification operating over the same unlicensed 60 GHz spectrum used by WirelessHD. WiGig 1.0 will automatically switch to 600 mbps, 802.11n for extended range and WiFi compatibility. They hope to incorporate next-generation known as 802.11ad at 60 GHz, although that spec isn’t due until 2012 or so. It’s backed by chip makers Atheros, Marvell and Broadcom, Dell, Intel, Panasonic and Samsung.
- Wireless Home Digital Interface at 5GHz: The WHDI Version 1.0 specification, also announced this week, is expected to compete with both WiFi and 60 GHz systems. WHDI claims speeds that are “equivalent” up to 3 Gbit/s (including 1080p/60Hz), using a 40MHz channel in the 5GHz unlicensed band. What “equivalent” means is anyone’s guess. Instead of compression, WHDI’s secret sauce prioritizes the most visually significant bits of a video stream. It relegates any glitches to the parts of the picture that aren’t changing. WHDI is backed by chipmaker Amimon, Motorola, Sony, LG, Samsung and Sharp. Amimon hopes to replace HDMI cables with the 5 GHz system. The first WHDI standard based products are targeted to be available to consumers in Q3 of 2010.
- Ruckus WiFi (at 5 GHz): Ruckus Wireless says it can reliably distribute High Definition IP-based video over Wi-Fi and has won support by European carriers and AT&T to make an option to connect U-verse boxes. Ruckus uses beamformed WiFi in the 5 GHz band, the 802.11n specification and compression.
- Quantenna at 5 GHz: Quantenna uses the Wi-Fi protocol 802.11n in the 5 GHz band and multiple antennas to transfer video. Quantenna combines 4×4 MIMO, transmit beamforming, vector mesh routing, and two or four concurrent bands for link rates up to 1 Gbps. Quantenna says compliance with Wi-Fi multimedia (WMM) 802.11e QoS standards allows for reliable handling of multimedia transmissions between various third-party Wi-Fi devices.
The wireless HDTV network battle looks to escalate at the Consumer Electronics Show next month in Las Vegas.
Related Dailywireless articles include; HomeNetworking: A Universal Spec?, Wireless HDTV: Battle of the Bands, WiGiG: WirelessHD + Wi-Fi?, Wireless HDTV Gets Amimon Chips, Ultrawideband Proponent Shuts Down.
