Home radio networks: One standard to rule them all?
Could a new one swim with the big fish?
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.
Fixed installation == wired networking
However not everyone can run structured cabling throughout. Homeplug is a winner because it's cheap, easy and works surprisingly well.
I take the point about HF interference but might be more sympathetic if, during the five years I held an amateur radio license, I came across a single ham who wasn't superior, obsessive, exclusive, perversely competitive and/or just generally unsavoury.
its all a crock of shit to me, until a wireless surroundsound system appears
A lot of Short Wave Listeners and Radio Amateurs are being affected by the interference that these Homeplug / Vision adaptors put out. Radio equipment is not cheap and why should someones hobby and interest be destroyed by some nasty, cheap technology that pollutes pretty much of the whole of the HF spectrum? Throwing wideband RF energy into mains cabling is such an ill-conceived idea and it's obviously going to cause widespread problems. As the author of the article mentions, there are many other technologies for moving data around the home. Why use PLT? Because of ease of use.
Many cases have been reported to Ofcom who are treating the matter as Spectrum Abuse.
Even the manufacturers of the chipsets (eg DS2) know that they cause interference to licensed users of the HF band because they incorporate notching into the devices. Its up to OEM's to implement the notching. In many cases the Amateur Bands are notched, but the International Broadcast bands arent.
Regarding "If some stone-age geeks who persist in communicating by CW shortwave rather than just picking up the phone like everyone else get buzzing in their earphones, then so be it, it is the price of progress" In the US the Amateur Radio service is an integral part in many disaster recovery plans and we have served in many times of need, for example on 9/11 to support the Red Cross and traffic between emergency services. There are also many other modes apart from CW which happens to be an extremely efficient mode of communication.