Original URL: http://www.theregister.co.uk/2008/08/04/home_radio_1/

Home radio networks: One standard to rule them all?

Could a new one swim with the big fish?

By Bill Ray

Posted in Data Networking, 4th August 2008 11:53 GMT

Radio technologies are sneaking into our homes - from wireless doorbells to Wi-Fi media streams - but as with any new market there's a plethora of standards vying for a slice of the home-automation pie.

Before we can consider the various wireless technologies on offer it's necessary to understand the problems they are setting out to solve beyond the primary motivation of making money for their inventors. Very few of the standards being pushed into the wireless home can provide everything from volume-control commands to high-definition video streams, so it's far from clear if one standard will come to dominate, though it would be equally surprising if all the proposed standards live to see out the decade.

Wireless technology has been in the home longer than any office, in the form of the humble TV remote control which morphed through various guises before settling on the infrared technology with which we are all so familiar. Infrared is great for controlling a TV, where line of sight is a given, but not so useful for music systems, light switches, motorised curtains and all the other fun stuff science fiction has been promising us for decades. For that stuff you need radio communications, though not a lot of bandwidth is needed for basic command and control.

How many TVs are in your home?

But it's not just command and control signals that are flying around the home wirelessly these days. Proprietary systems operating on 2.4GHz, and increasingly 5.8GHz, have been resending TV pictures around houses for years and generally carrying command and control signals the other way to enable users to control their Sky TV boxes from the bedroom. Such systems offer a limited quality signal - good enough for most people, but also restricted to being point-to-point connections, while punters these days want more of their kit talking to each other. Sony reckons it'll have 90 per cent of its products wirelessly networked within the next two years, and those devices will all want to be talking to each other.

For many years the industry believed that the key to convergence was putting the web onto a TV screen - something that quality and usability have always made more of an ideal than a practical reality (though the Wii/Opera experience comes close). Computers are locked away in the spare room, and few people will put up with CAT-5 cable trailing around the house, so the idea was to put the intelligence into the set-top box and leave the computer for the geeks and teenagers. But wireless connectivity has changed all that and these days ordinary users are squeezing media players under their TVs, and streaming content from their computer hard discs as well as over the internet, reinventing the computer in the spare room as a media server of sorts.

Right now the dominant technology is Wi-Fi, the name given to the 802.11b/g/n standards, all of which operate in the 2.4GHz channel. 802.11a is starting to gain traction as 2.4GHz fills up - 802.11a uses 5.8GHz, which is also unlicensed and, for the moment at least, less crowded. But the dominance of Wi-Fi is far from unassailable in such a nascent market: Ultra Wide Band (UWB) offers much greater bandwidth, though at shorter range, and 3G technologies can also stream video around the house via a femtocell in frequencies owed by the cellular network operators, thus guaranteeing bandwidth. It's also worth noting that femtocells will be pushed hard by the operators, so the deciding factor may well not be technology or usability at all.

In command and control a plethora of new technologies are vying to take on the infrared zapper: Bluetooth Low Energy, Zigbee, Z-Wave, and Intel's Cliffside to name a few, and those are complimented by Near Field Communications and RFID devices which aim to provide some of the short-range functionality if not the interactivity.

We'll be looking in more detail at the options for high and low-capacity home wireless technologies in future articles, but for the moment we'll take a look at what's wrong with the primary consumer-radio technology in use today - Bluetooth.

Bluetooth owes its survival to the way it was developed: Engineers sat around and decided what they wanted to be able to do, then developed a standard that would do that. This made Bluetooth very capable, though the designed-by-engineers background still shows through when it comes to usability.

Picking holes in Bluetooth

The most popular radio standard fits right between the usage models we've defined for the home. It's unable to carry a decent video signal, though these days it can carry proper (albeit compressed) audio, and while it was designed for low power consumption the world has moved on and these days it consumes far more power than the competition.

But the criticism most often levelled at Bluetooth is the complexity of pairing - connecting devices together for the first time so they can communicate automatically in future. To the engineers who designed Bluetooth the idea of selecting a named device, then typing the same four-digit code at both ends, seemed a trivial process, but to today's Bluetooth user it's cumbersome and impractical - especially for headsets and other devices lacking a keyboard of any kind.

The Bluetooth SIG has addressed pairing in version 2.1, allowing devices to automatically advertise their presence when first powered up, though not a lot of devices support that process as yet.

So, for a wireless standard to find a place in the home it's going to have to resolve the pairing issue, and peg itself below Bluetooth in the low-power-low-bandwidth category, or above it in the high-power-high-capacity arena where Wi-Fi is currently dominating.

As for Bluetooth, the standard is trying to reinvent itself as an umbrella protocol - a channel over which other standards can be negotiated. It's a popular role, and one that Near Field Communication is targeting, but without it there's nothing to stop Bluetooth being squeezed from above and below as the needs of the wireless home coalesce into two distinct models, with Bluetooth falling squarely between them.

Over the next week or two we'll be taking a closer look at those models and the technologies hoping to serve them, to try and establish if the wireless home of the future is going to bear any resemblance to what we were promised when we were kids. ®