Wouldn't it be nice if you could listen to music streamed from the Internet over a good sound system while lying on a comfy couch, untethered from the PC at your desk? And while we are dreaming, wouldn't it be great if regular, nontechnical folks could watch movies-whether played back from a DVD player, downloaded from a personal video recorder or streamed from broadband media-in any room of the house?
Both visions should be doable today, but they're not. You have to be an engineering whiz to set up a home network on your own, especially if you need to mix and match home entertainment equipment you already own-most likely wired-with a couple of brand-new AV systems or PCs featuring a wireless technology.
After overcoming the primary hurdle of getting everything connected, an even bigger issue is likely to haunt both consumers and those who hope to sell them home-networking technologies: namely, the quality of audio and video. Could Dad in his den, for instance, send his favorite Stephen Seagal movie over to Mom in another room, streaming it glitch-free with no visible degradation of the original DVD picture quality? Would the whole thing crash and burn the minute Junior, up in his room, added one more device to the home net, interfering with other functions or even ruining the network for everybody by hogging all the available bandwidth?
No single consumer electronics company has the answers to all these questions. But the engineering community is beginning to get nightmares about consumers demanding their money back from retailers, insisting that "something must be wrong with your system because it doesn't work in my home network."
Testifying to just that concern are many of the engineering developments detailed in technical papers submitted to the International Conference on Consumer Electronics, to be held this week in Los Angeles. The topics to be covered at this year's ICCE are diverse, ranging from wireless multimedia networks and still and video cameras to watermarking and encryption technologies. But a recurrent theme in multiple sessions is the technical challenge of implementing home nets.
In this week's In Focus, contributors-most of them researchers who will also present these articles at ICCE-outline their solutions to these and other implementation issues surrounding home networking.
Many engineers in the CE industry are pondering the technical issues anticipated when multitudes of network technologies-both wired and wireless-are asked to coexist harmoniously in the complicated home of the future. Any number of consumer boxes-PCs, TVs, set-top boxes, home servers-are expected to hook into these networks, running several applications that may have different network requirements.
"As long as you're connected to a DSL [digital subscriber line] and all you want to do is Web surfing, 802.11b wireless Ethernet works great. No problems," says contributor Glen Stone, director of strategy, standards and architecture in the Network and Systems Architecture Division of Sony Corp.'s Platform Technology Center of America. But once you start putting video over Ethernet, he said, you find that Ethernet has no quality-of-service (QoS) features, that wireless tends to lose packets and that you can't resend those lost packets in streaming applications. "Not enough bandwidth and not enough reliability are two issues you need to face up to," Stone notes.
Peter Chow, CTO at Texas Instruments Inc.'s DSL Technology Center, describes the development of next-generation DSL by folding new techniques like ADSL2+ and reach-extended ADSL into a single chip. Calling DSL "the most promising broadband delivery mechanism," Chow and co-author William A. Santini promise a new single-chip ADSL customer-premises modem/router that is capable of delivering up to 20 Mbits/second of data to the home network.
Beyond the issue of establishing a broadband connection, Sony's Stone and his co-author, Virginia Williams, director of technology and standards at the Consumer Electronics Association, take a further step into the future, describing how 1394 and Ethernet networks will be bridged within one home net. Their joint article outlines the industry organization's ongoing efforts in developing QoS priority groups for Ethernet and an adapter that connects dissimilar networks-such as 1394 and Ethernet-by converting protocols.
In an exclusive online contribution, Richard Chen and Mihaela van der Schaar at Philips Research delve into the development of bandwidth- and complexity-scalable video-coding technologies that enable adaptive video transmission. Their premise is that in the future, multimedia data will be streamed over a variety of access networks, such as GPRS, UMTS and wireless LANs, to a multitude of devices including PCs, digital TVs, PDAs and cellular phones. Their piece defines a solution that facilitates access to multimedia data by a large number of users (or client boxes) at any time, from anywhere.
Also online, Korea University's Jae-Young Pyun reviews QoS provisioning for video streaming over IEEE 802.11 wireless LANs, while Arun Arumugam and Andrew Nix at the University of Bristol, England, outline evolution technologies they have developed for enhanced Bluetooth-enabled devices. "In order to achieve reliable performance, particularly for time-bounded applications such as video and audio streaming, interference issues need to be addressed and suitable interference mitigation techniques must be deployed at the Bluetooth device," they write.
Their initial investigations focused on co-located piconets containing enhanced data rate Bluetooth devices. "Results suggest that enhanced data rate Bluetooth-enabled devices are only capable of handling mutual interference provided the number of interferers are low," they write. In a more recent study, antenna diversity was exploited using a method called space time block codes (STBC) with maximum-likelihood (ML) decoding. "Results showed that the reliability of both time-bounded and non-time-bounded Bluetooth-enabled devices in the presence of interferers were enhanced by using STBC coupled with suitable interference cancellation techniques," they note. "The improvement was significant, particularly when a high number of interferers were present in the environment."
As the number of networked appliances proliferates within the home, the user interface becomes a larger issue. For consumers already burdened with too many remote control units, even selecting the right appliance for playback is a looming nightmare, let alone dealing with a different user interface for each of them. On top of that are questions involving support for multiuse operation, user identification and differentiated services for each user. On this front, Yoshihiro Kawahara at the University of Tokyo and Masateru Minami at the Shibaura Institute of Technology introduce in their online exclusive a "smart-baton system" to clarify what the user interface device should be like in the home of the future.
They explain that pointer-based manipulation techniques "make it possible for users to download a user interface to their handheld devices via wireless nets as well as to select the appliances with a laser pointer. The system modulates user's ID onto the laser beam, the target appliances are able to recognize multiple users' operation to provide differentiated services to different users."
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