With the high-def disc war now firmly in its rearview mirror, the consumer electronics industry is girding for its next skirmish: the battle to see which of the various new wireless HDMI technologies will emerge as the de facto standard.
When HDMI broke out from the pack of new digital connections back in 2004, its ability to carry both digital audio and video signals on a single cable promised to rid homes of cable clutter caused by the various interconnects stretching between source components, receivers, and video displays. But with ultra-slim flat-panel TVs making an aesthetic statement as much as a technological one, apparently even a single cable is one too many. While companies have been playing with various wireless video technologies for half a decade, this past Consumer Electronics Show was jam-packed with announcements that products capable of wirelessly transmitting a high-def signal will be available starting this summer. Leading the charge are four technologies: Wireless Home Digital Interface (WHDI), WirelessHD (WiHD), Ultra-Wideband (UWB), and 802.11n.
The first wave of products will likely be add-on transmitters and receivers that can be plugged into source components and TVs, although some TVs might have embedded wireless chip sets later in the year. While no outright winners came out of CES, it appeared that the two newest approaches, WHDI and WiHD, had gained considerable momentum. (One clear sign of the current fluid state of wireless is that several leading companies, including LG, Samsung, and Sony, are members of several of the promotional groups formed around each of the four technologies.)
To be sure, all wireless technologies face challenges, ranging from cost to performance. To qualify as HDMI replacements, these technologies have to closely mimic the performance and reliability of wired connections despite working in a constantly changing environment. That means providing the consistent bandwidth and the transmission speeds required by high-def video, plus built-in error resiliency, low latency, and support for control protocols such as CEC (Consumer Electronics Control). Also, all have to include some form of Hollywood-approved copy protection, and many will have to conform to the interoperability requirements of various organizations, such as the Digital Living Network Alliance (DLNA), the High-definition Audio-video Network Alliance (HANA), and the Wi-Fi and WiMedia Alliances.
Here’s a look at what each of the four wireless approaches promises to deliver.
Developed by the Israeli company Amimom, WHDI is backed by a special-interest group that currently includes Hitachi, LG, Motorola, Samsung, Sharp, and Sony. WHDI delivers uncompressed video — including 1080p/60 — throughout the home using the unlicensed 5-GHz band, with data rates as high as 3 Gbps (1080p) by way of a 40-MHz channel or 1.5 Gbps (720p and 1080i) at 20 MHz. WHDI supports the CEC protocol and High-bandwidth Digital Content Protection (HDCP) v. 2.0 technology used in wired HDMI. Because 5 GHz moves easily through walls, WHDI is regarded as a whole-house, rather than in-room, wireless technology (like other 5-GHz technologies, such as 802.11a and 802.11n Wi-Fi), with a range exceeding 100 feet. Spectrum-management technology helps to avoid potential conflicts with other devices sharing that band.
While acknowledging that most source material comes into the home in compressed form, backers of WHDI say its ability to send uncompressed video most mimics wired connections. That’s because compressed video is rarely available at the output of most A/V, gear due to copy protection (compressed video is more susceptible to theft) and to interoperability issues caused by the use of different video codecs. Of course, the counter argument is that since source material is compressed, there’s no reason the compressed stream shouldn’t be carried all the way to the display.
WHDI’s key supporters include Sharp, which is using it in its ultra-slim TVs, and Sony, which incorporates Amimom’s chips in its Bravia Link DMX-WL1 wireless system ($800), though it’s limited to 1080i video. Non-TV offerings include Belkin’s FlyWire ($1,500) and Gefen’s GefenTV Wireless for HDMI 5-GHz extender ($900). FlyWire, with support for 1080p/24 video, includes a transmitter, receiver, remote control, and IR repeater. Gefen’s system supports 1080p/30 video, 5.1-channel digital surround sound, and 2-channel analog audio.
If CES had any wireless winner, our money’s on SiBeam’s 60-GHz WiHD, which got a boost when LG, Panasonic, and Toshiba all promised add-on WiHD wireless capability for TVs this year. The technology is backed by a consortium that, in addition to those three companies, includes Broadcom, Intel, NEC, Samsung, and Sony.
At the heart of WiHD is SiBeam’s OmniLink60, which sends uncompressed (or lossless) HD video by way of the unlicensed 60-GHz band, at rates up to 4 Gbps over a 30-foot range. Current chip sets support up to 1080p/60 video and 8-channel high-rez audio, but backers say the technology has a theoretical data rate as high as 25 Gbps, making it scalable for the higher resolutions and color depths that will come with next-generation panel technology (such as 4K displays). Like WHDI, it includes support for device control protocols (such as CEC), but it uses another Hollywood-approved copy-protection scheme called the Digital Transmission Content Protection (DTCP) protocol, originally developed for FireWire.
With its more limited range and its inability to pass signals through walls, WiHD is positioned as an in-room technology. (Devices can be hidden out of sight beyond a door, though.) While the 60-GHz spectrum has plenty of bandwidth to handle uncompressed high-def video, it’s highly directional, so products have typically required line-of-sight operation. Another sticking point: 60-GHz waves can’t pass through water, a major component of human bodies. That means that communication between devices can break down any time someone walks between a transmitter and receiver.
But OmniLink60 uses real-time adaptive “beam-steering” technology to provide non–line-of-sight operation. Employing tiny arrays of antennas, the system automatically surveys the room to find the best transmission path. If a direct path isn’t available, it will bounce signals off walls, ceilings, floors, or even other objects. And if a transmission path gets blocked — say, by someone who’s walking into the room — the system simply switches to the next best available path with no disruption of the video stream. It can also automatically detect new devices and add them to the in-room network.
Based on CES announcements, LG will offer separate WiHD media boxes for its 55-inch LHX and 47- and 55-inch LH-85 LCD models, as will Panasonic in its ultra-thin Z1 plasmas. Toshiba said it would have a WiHD adapter for its Regza LCD TVs later in the year, and Gefen will support the technology in its GefenTV Wireless for HDMI 60-GHz extender (price to be announced).
Although it’s had a few false starts (Philips, for example, announced a product in 2007 that still hasn’t seen the light of day), UWB also made a positive showing at CES, primarily in new wireless systems from Monster Cable and Gefen. UWB operates in the 3.1-GHz to 10.6-GHz spectrum, and so far has been limited to a maximum data rate of 480 Mbps at distances of less than 10 feet, or 110 Mbps at the end of its 30-foot range. As a result, it’s best suited for in-room applications, although it doesn’t require a direct line of sight, allowing components to be located in an adjacent room or closet.
A key selling point of UWB is that it’s a proven technology (the FCC gave it the okay back in 2002) with greater throughput and less susceptibility to interference or fading than Wi-Fi. UWB can handle 1080p video signals, but it requires compression (such as Analog Devices’ JPEG 2000 or H.264) to do so. Its backers, however, say technological enhancements — such as the use of multiple antennas in transmitters and receivers (multiple-input/multiple-output, or MIMO), which can send simultaneous data streams to pump up data rates, and “smart” (beam-forming) antennas — are helping push performance into gigabit territory. A UWB standard called WiMedia has been created by the nonprofit WiMedia Alliance to help ensure interoperability between all WiMedia-compliant devices in the home, regardless of brand.
Several companies, including Tzero, Radiospire, and Pulse-LINK, have developed UWB chip sets that are expanding the boundaries of the technology, including improvements in video quality, latency, and error resiliency caused by fluctuating channel bandwidth. Tzero’s first chip set, used in Gefen’s wireless UWB media extender, employs JPEG2000 video compression, but a newer version using the H.264 codec is said to deliver a maximum data rate of 480 Mbps, with full support for 1080p/60 video and 7.1-channel digital audio at a maximum range of about 60 feet. The chip sets also support CEC and include digital copy protection. Pulse-LINK, which gained attention by partnering with Westinghouse for commercial TVs with its CWave UWB technology, has a reference design that allows CWave to work both wirelessly and over coax simultaneously from the same chip set.
At CES, Monster Cable garnered attention with its Wireless Digital Express HD system ($999), which is based on a Sigma Design UWB chip set. The hybrid wireless/coax system uses an H.264-compliant decoder and Sigma’s UWB Over Coax chip set to send up to 1080p video wirelessly within a room, or up to 330 feet using existing coaxial cable. The system can upscale all content to 1080p and comes with three IR emitters. Gefen’s currently available Wireless for HDMI UWB Extender ($999) uses Tzero’s UWB chip set to support 1080p/30 HD video with 7.1-channel digital surround sound and 2-channel analog audio.
Working in the same 5-GHz band used by WHDI, 802.11n — a.k.a. Wi-Fi — is nothing if not ubiquitous, although it’s still used more for computer-based wireless broadband networks than for streaming high-def video. Like UWB, 802.11n employs compression to send high-def video between sources, but its 100-foot-plus range makes it suitable for A/V distribution throughout the entire house. Although “draft n”-compliant products have been available for well over a year, the 802.11n standard won’t be finalized until this June.
The 802.11n technology has a maximum data rate of about 150 Mbps (using MIMO, part of the 802.11n spec). Proponents argue that next-generation Wi-Fi is a proven technology capable of inexpensive high-def video delivery to all the rooms of a house. But critics worry that Wi-Fi’s lower data rate, higher latency, need to support legacy devices, and greater susceptibility to bandwidth fluctuations and fading make it a poorer choice than competing technologies for sending HD video. A few TV manufacturers, including LG (the LG71) and Samsung (FP-T5894W), have offered TVs with separate Wi-Fi-enabled media modules, but so far the technology hasn’t taken hold.
As things stand, 2009 could be the year that wireless HD technologies jump from promise to reality, although consumers could well be overwhelmed by the multitude of choices and technologies. In the near term, it’s likely that several technologies will coexist in the market to be used for specific applications.
Now if we could just do something about those power cords.