Video room service

EDN's Digital Den recently played host to one of the few shipping products that uses wireless technology to boldly send video to televisions in areas of a home where no wire has gone before. Although Belkin's PureAV RemoteTV system is impressive for its simplicity and solid performance, it also exhibits drawbacks that underscore a real-world reality: Much work remains before wireless technology becomes a standard component in the home-media-networking infrastructure (Picture).

The product allows a TV in one room to receive video content from a source device—such as a DVD player, PVR (personal video recorder), or set-top box—in another part of the house. RemoteTV is by no means the first product to wirelessly transmit TV signals within the home. However, it is the first to arrive in the Digital Den that combines in one unit a number of key features (see sidebar "Wireless-video menagerie" for a look at competing products).

First, RemoteTV delivers full standard-resolution video (720×480 pixels). Second, it can work with any source device and any monitor. And, finally, it relies on Air5, a wireless chip set from Magis Networks. Air5 uses a proprietary MAC (media-access-control) layer that supposedly ensures smooth video delivery. Meanwhile, the technology uses the 5-GHz 802.11a physical layer in order to avoid interference from 2.4-GHz Wi-Fi networks, cordless phones, and microwave ovens.

The RemoteTV box includes the lookalike transmitter and receiver units that make up the system, as well as twin power adapters, twin RCA cables, and an infrared remote-control extender.

Setup proved refreshingly mindless, requiring not even a glance at the included quick-start guide or manual. In the room where we intended to watch, we wired the receiver unit to a TV and stereo system. The receiver offers three video-output options: a composite-video jack, an S-Video connector, and a set of component outputs.

We stationed the transmitter unit in a room about 30 ft from the viewing room and wired it to the DVD player that would serve as our source device. The transmitter offers inputs in the same flavors as the receiver's outputs. It also includes wired outputs that allow the user to play video from the source device on two displays at once (one near the transmitter, fed through physical cables, and the second in the remote location, fed by the wireless link). Belkin suggests that parents working in the kitchen, for instance, might use this feature to monitor what their kids are watching in the family room.

The transmitter unit also includes a jack for the remote-control extender—simply a short cable with an infrared transmitter on the end. Positioning this infrared transmitter near the source device allows RemoteTV to spoof the source device into thinking its remote is still in the same room. When the user in the distant viewing location presses a button on the remote, the RemoteTV unit there picks up the signal and transmits it to its twin, which in turn feeds it to the source device via the extender. Presto: No need to run from room to room to pause a DVD or change channels.

Within seconds of powering up the receiver and then the transmitter, green "link" LEDs appeared on both units, signaling "all systems go."

The user experience with RemoteTV proved all but indistinguishable from a conventional wired setup. The DVD player responded rapidly to commands issued via the remote control. The sound and picture stayed in sync. And the system behaved in a rock-solid, crash-free fashion.

We paid particular attention to picture quality, swapping the DVD player back and forth from the RemoteTV connection to a direct, wired connection in an attempt to spot any anomalies. In both configurations, we repeatedly inspected specific sequences from two DVDs, a live rock-music performance and an animated feature film.

RemoteTV takes whatever input the user provides, encodes it into MPEG-2 format, transmits it, and then decodes it for presentation to the connected display. As a lossy-compression process, MPEG-2 by definition degrades the video stream at least a little. The question is whether the viewer will be able to perceive those changes.

Moreover, DVDs, many PVRs, and cable- and satellite-TV systems all use MPEG-2 for encoding. So, when a consumer employs one of these source devices in conjunction with RemoteTV, the video signal runs through two encoding/decoding cycles. If the consumer uses a stand-alone TiVo to record a show from, for example, a DirecTV feed, and then watches the program on a monitor connected via RemoteTV, that video stream runs through the MPEG-2 wringer three times. And, as experience with everything from cassette tapes to MP3 files attests, repeated runs through a lossy compression process can do appreciable damage.

Happily, despite considerable effort, we could not detect any loss of picture quality or any addition of compression artifacts. States Carrie Brown, a Belkin senior product manager: "Our encoder chip has a very high sampling rate, so the quality will not be degraded. It will be of the same quality as the source when it reaches the display." Although one might argue that this claim is not true in the strictest sense (because MPEG-2 does throw away some information), we agree that RemoteTV reproduces the source video faithfully enough to satisfy even discerning consumers.

Belkin claims that RemoteTV offers whole-house coverage. In our tests, the system worked perfectly at distances of 30 and 55 ft with both units on the same level of the building. It also performed flawlessly with the transmitter stationed about 25 lateral feet away and one floor below the receiver. However, the units failed to establish a connection during our most extreme test, when we placed the transmitter about 110 lateral feet away and one floor down.

Belkin's Brown admits to being a bit stumped by this result. The company has tested the system beyond 350 ft with line-of-sight between the units and has also achieved stable connections through multiple steel walls at distances up to 150 ft, she says.

The building in which we tested RemoteTV is an apartment building, and Brown speculates that it may have metal structural components that are wreaking havoc with the wireless link. She expresses confidence that the whole-house claim will hold up in homes featuring conventional wood framing. Nevertheless, the experience serves as a reminder that buyers of wireless products should save their receipts until they've got the products up and running in their own homes.

One other glitch happened a couple of times during our range tests, when we moved the source DVD player and the RemoteTV transmitter from one location to another. Upon powering up, the system provided crystal-clear video but no audio. Power-cycling both the transmitter and the receiver solved the problem. We consider this problem minor, because most users set up the system in one location and leave it there.

Belkin's RemoteTV did almost everything it promised with an assurance and ease that are sadly rare in tech products today. That said, the system is no bargain at $499.95—especially considering some of its inherent limitations.

First, the system offers little flexibility. It supports only analog audio, and the consumer can connect at most three video sources—one through S-Video, one through the component jacks, and one via the composite input. (A hardware button on the front of the receiver rotates among the three.)

More significantly, the device maxes out at 480i (480-line, interlaced) resolution; it cannot deliver the 480p signal that a progressive-scan DVD player provides. So, consumers who justifiably prefer the superior clarity of a 480p signal rendered on a digital monitor have to look at other options for networking those components. The system can't deliver an HDTV signal, either.

It's difficult to understand the omission of 480p and HDTV support, especially because the consumers likely to be interested in wireless-video networking (and able to afford $500 gadgets) are also likely to own HDTV monitors and be aware of the advantages of progressive-scan output.

One might expect Belkin to blame bandwidth constraints for the shortcomings. However, the Air5 system provides a healthy 40 Mbps—more than enough to transmit a 480p signal or a compressed HDTV stream. Instead, the issue lies with encoding horsepower, according to Brown. "It was an issue of market availability of the encoder components," she says. Adding, "480p support is being developed by the chip manufacturers, but at this time it is not available. To be able to do anything higher [than 480i] would require an extremely high sampling rate of the uncompressed data. Therefore, it is unlikely for 720p or 1080i to be supported."

Handling of such formats will have to wait for an all-digital approach that eliminates analog-digital-analog transitions and repeated encoding and decoding, she suggests. A wireless FireWire connection, perhaps using UWB (ultrawideband) wireless technology for transport, might do the trick. And in fact, the industry is hard at work on similar approaches. But it will take time to iron out technical and copyright issues, not to mention convince consumers to buy compatible TVs and video components.

Though it would be nice to see the RemoteTV system support 480p and HDTV, blaming it for failing to do so is a bit like chiding Lewis and Clark for not bringing along steam locomotives. As a pioneering product, RemoteTV does an admirable job of delivering the features that are practical today. As silicon advancements help reduce the price, it may find some success.

Eventually, advanced home-networking products will make any piece of content available at any location in the home with the highest possible resolution and umpteen-channel audio. For now, RemoteTV is a notable achievement along the path toward that grand goal.

You can contact special projects editor Matt Miller at 617-558-4714, or e-mail mdmiller@reedbusiness.com.