Can it be true? Has wireless HDMI
finally arrived? For the past couple of years, manufacturers have teased us with demonstrations of wireless HD video transmission. Some of these demos even came with specific product release dates, but sadly, those dates always came and went with no products actually appearing on the retail shelf. I was beginning to give up hope on the wireless HD revolution, but it appears that 2009 is finally the year. Manufacturers like Sharp and Panasonic have introduced high-end TV models that incorporate wireless HD video transmission, and Sony's
proprietary Bravia Wireless Link Module is available for Bravia HDTV owners.
• Look at plasma HDTV and LCD HDTV options for Gefen's system.
• Find a Blu-ray player to integrate with this system.
What if you already own an HDTV (and it isn't a Sony)? Is wireless HDMI still an option? Thanks to Gefen, it is. The company has released not one but two standalone wireless HDMI systems: one for in-room applications and one for multiroom applications. Naturally, I jumped at the chance to see how well these new products deliver on the enticing promise of wireless HD.
A number of competing wireless HD transmission technologies are vying for the attention of manufacturers and consumers at this point, including 802.11n, UWB, WHDI and WirelessHD. What distinguishes them is the frequency band in which they operate and the type of compression they use or don't use, as the case may be. Gefen has opted to employ UWB, or ultra-wideband, for its in-room application and WHDI for its multi-room application. Both Gefen products support HD video resolutions up to 1080p/30, as well as compressed 5.1-channel audio soundtracks (Dolby Digital and DTS) and two-channel PCM up to 48kHz. The boxes include a sender unit that attaches to your sources, a receiver unit that attaches to your display device, power adapters and a single HDMI cable.
Wireless for HDMI UWB
The Wireless for HDMI UWB system (EXT-WHDMI, $999) uses a UWB platform developed by Tzero Technologies. Ultra-wideband is an RF technology that (as the name suggests) sends bursts of information over a wider frequency range, so it's less susceptible to interference. The Gefen product operates in the 3.1- to 4.8-GHz range and uses a compression technology called JPEG2000, which Gefen says offers a throughput of 65 Mbps. UWB is ideally suited for line-of-sight, short-range communication, around 30 feet, which is why this product is best used as an in-room solution. In my case, I sent the signal from an equipment rack located in the back of the room to a Samsung HDTV located in the front of the room, about 13 feet away.
Physical set-up is quite simple, requiring nary a peek at the owner's manual. The sender and receiver units are horizontally aligned boxes, about half the length of the average source component, with antennas sprouting from the top. The sender unit has two HDMI 1.2a inputs and one component video input, along with a stereo analog audio input, to accommodate a total of three high-def sources; the receiver unit has a single HDMI 1.2a output, plus a stereo analog audio output, for connection to your display device. I fed HDMI from my DirecTV HD DVR and Pioneer Blu-ray player directly into the sender unit. The sender unit's Select button allows you to switch between the three inputs, with blue LEDs that indicate which source you've selected. The package doesn't include a remote control to switch inputs; however, you can enable an Auto function that detects the first connected HDMI source and switches to a new HDMI source when you power it up.
If you need to connect more HD sources and/or want to remotely control the switching function, the better hookup option is to simply feed the HDMI output from an A/V receiver or external video processor into one of the sender unit's HDMI inputs and let that device handle the switching duties. I tried this approach using a DVDO scaler, and it worked fine. The UWB product incorporates an IR repeater system. The receiver unit can send IR commands from your remote back to the sender unit, which has an IR blaster port to connect to your gear.
The sender and receiver units sport LEDs for Link and Video, both of which should glow a steady blue when the handshake is established and video is transmitting properly. Happily, this is exactly what I got when I powered everything up.
Wireless for HDMI 5GHz
The Wireless for HDMI 5GHz system (GTW-WHDMI, $899) is designed to travel over a longer distance (up to 100 feet) and work more reliably through walls and other obstructions. The 5GHz model (it actually works over the 5.1- to 5.8-GHz band) is based on WHDI, a technology created by Amimon that allows for the transmission of uncompressed HD signals. The vertically-oriented sender and receiver units resemble modems and come with simple snap-on bases. The front panels contain just two LEDs: one for power and one for link. The latter flashes quickly when there's no link, flashes slowly when the handshake between sender and receiver is established, and glows solid blue when the A/V signal is transmitting properly. In terms of connections, the sender unit has just a single HDMI 1.2 input, while the receiver unit has one HDMI 1.2 output, plus a stereo analog audio output, to connect to your displace device. As with the UWB model, I experimented with direct connection of each source to the sender unit and also tried attaching the DVDO scaler to switch between multiple sources; I sent the signal wirelessly to a TV located on the second level of the house, with about 25 feet from source to display through the floor. Once again, after I connected everything and powered it up, the A/V signal appeared on the remote TV with no issues.
The 5GHz model has two modes, Unicast and Broadcast. The default Unicast mode lets you use only one receiver per sender; the Broadcast mode will send the signal to five receivers, but does not support HCDP material.
PerformanceRead more about the performance of the Wireless for HDMI system on Page 2.
When it comes to performance, the two key issues for any wireless HDMI product are signal reliability and video quality. In both of these areas, the Gefen products prove themselves up to the task. In regards to signal reliability, the 5GHz model never dropped the signal or exhibited even a minor interference hiccup. You'd never guess that the HD signal was being transmitted wirelessly from another room. I was most curious to see how the in-room model would perform, since UWB is more prone to interference if there are too many obstructions between the sender and receiver. Gefen recommends you place the sender unit at a height of at least five feet for optimal performance (the receiver unit's height does not matter), and indeed at this height I encountered no signal drop-outs, even when I parked myself directly between the sender and receiver antennas and tried to cause a disruption. Next I tried lowering both products to the floor, and still the link remained intact. I also tried moving the sender unit into the next room at about the maximum recommended distance of 30 feet, with one wall boundary in between, and the two devices still communicated just fine. Only when I moved the sender even further away and added a second wall boundary did the link finally break. So, even though Gefen recommends line-of-sight, the UWB system is stable enough to accommodate some obstructions.