I thought a whole load of things ran in the 2.4GHz band these days: garage door openers, wireless doorbells, etc.
At my previous place of work we had to get rid of a microwave as it would kill the wireless as soon as it was switched on.
A five-month project to map spectrum usage has yielded 200GBytes of data, which shows that hardly anyone in the Highlands is using wireless, but the rest of the country is swathed in electromagnetic radiation. The project report (pdf) includes snippets of information to demonstrate the validity of the project. The raw data …
Suggest you look at page 3 of the report. Their "coverage"of the Highlands consisted of driving up or down the Great Glen and driving up the east coast to Wick.
Given that there are some serious mountains around - that's why it's called the Highlands - it's no surprise that they didn't detect much.
I'll grant you that there is hardly anyone in the Highlands. But I would expect that the proportion of the population there using wireless devices is probably higher than in most other regions of the UK. In addition to the general population and the emergency services, the nature of the terrain and the uses to which it is put make the use of wireless essential for many people - farmers, forestry workers, gamekeepers, mountain rescue teams, etc etc.
Paris because everything she says is a mysterious emission.
Just North of Cambridge you'll find DB Technology where all the local high-tech startups take their new gadgets for EMC testing. If you drive past there on the wrong day you could find all sorts of bizarre emissions.
Oh, and Millom isn't a village. It's a dump. I mean, it's a town.
This is almost certainly a '1.2GHz' video sender, probably bought off ebay. They're quite common, and are nowhere near 1.2GHz in most cases. They can also be remarkably high power. Not legal for unlicensed use, even if they WERE on 1.2GHz. They're normally simple but robust transistor oscillators, not PLL based, and are usually just above 1GHz. The manufacturers often go to significant trouble to disguise how simple the things are, to the extent of soldering down a number of random dummy chips that aren't even connected to anything to make it look more complicated than it really is.
I had a very small (about the size of a sugarcube) transmitter of this type some years ago. It was a very simple, two-transistor, video only unit, but produced nearly 200mW of RF. It was tuned to 1.064GHz, very close to this 1.075GHz one. Surprisingly, for such a simple and cheap thing it produced very good video quality. However, when I measured it's output, I decided that transmitting on a military navigation beacon frequency wasn't a very good idea...
Would love to see the map for my house.
Aside from the dozen or so wireless transmitters I personally have, the place is swamped by at least a dozen neighbouring wifi signals, plus all their other wireless gadgets, the mobile signals passing through the place along with I suspect some transmissions from the nearby electricity substation (which appears to have a data connection judging by the massive sat dish on top). Not to mention the EM emissions from the substation and pylons.
If I haven't already got brain cancer, leukaemia and what-not, I probably will. Time to build a Faraday cage I think. Tinfoil hat might help too.
As google are already recording EM waves in the 400THz to 790THz frequency band and displaying them in map form, why not add some seperate detection equipment to the googlemobiles to detect in the 10Mhz to 10Ghz range at the same time and display them as an additional overlay on the map? Would give the tin hat brigade something to worry about and therefore the rest of us to laugh at.
Actually it doesn't show that hardly anyone in the Highlands is using wireless. If you look at Figure 1, "Track taken by survey vehicles across the UK" in the PDF you'll notice that readings are constant over the routes travelled. None of the islands were visited - that doesn't mean that there's no wireless there, just that they weren't measured.
No matter how many sensors it carries, the data collection vehicle is not going to detect anyone transmitting using a sat dish, too directional.
Plus, the incidence of WiFi usage is going to depend on how long people's front gardens are - long garden = no detection of WiFi signal = no WiFi in use?
Yup, they hardly touched the Highlands, did not even go up the A9 between Inverness and Perth. Around here (15 miles north of Inverness) there are plenty of domestic wireless networks and about 10 BT FON public networks within a mile. Loads of them around the Western Isles as well. The Western Isles also has a broadband wireless backbone (not sure of the technology). And plenty of BT microwave links all over. No 3G where I am though.
"Most interesting are the anomalies highlighted, such as high-powered transmissions being found around 863-870MHz. That spectrum is supposed to be for short-range devices: wireless light switches, remote key fobs, and the like."
The ETSI spec EN-302-208 RFID band is 865 MHz to 868 MHz with power levels up to 2 W.
I thought OFCOM had a remotely controlled monitoring network that was used for spectrum surveillance? It is not as comprehensive as vehicle driving around but would have thought they had got some useful data from that.
Then their is other RF surveillance network that is said to have been installed.
Be funny if the videosender was being used by the police to spy on someone!
An interesting excercise as a pilot, but their coverage is woeful for anything short range like 802.11g. To say that 65,000km of roads covers most of the population is somewhat disengenous. For short range stuff you need to be within a few meters of the source, lets be generous to them and say 10m. What percentage of properties in the UK did their detectors get within 10m of?
I can see about a dozen APs from my house. Even if they did come past on the nearest A road (about 15m from the house) fact that the road sits beyond a 2m high retaining wall a the end of our garden means that they are unlikely to have seen much of the signals emenating from our street. So anybody using their tool to check out 2.4GHz saturation would think there was little or no usage on our street. Useful.
>Would give the tin hat brigade something to worry about and therefore the rest of us to laugh at.
Laugh all you want but it may be no coincidence that as the level of electromagentic radiation increases in highly populated areas so does the level of stupidity among the general population. Historically every empire had it's new thing that eventually led to it's downfall more often than not as a result of turning the people into blithering idiots.
You're quite right. I've been surprised (appalled?) to see how many devices blat all over 2.4GHz. There are loads of (really cheap) wireless CCTV cameras that use that taking about 3-4 of the normal channels each! Doesn't leave much for WiFi. Whereas a proper IP camera running over WiFi costs quite a lot more.
"...the highest powers do not relate to wireless LAN activity, but rather that other technologies are being used in this band." - That'll be the poor unfortunate souls with leaky Microwave ovens... or perhaps one of those Radio Amateurs bouncing a few kilowatts off the moon near moonrise/moonset... with all the Radio Interference it takes a bit of power to reach the Clangers these days.
I'm going to get my tin foil microwave resistant coat out quick.
So now that tax money has been spent doing this survey, why aren't the results public? Instead they will bit-rot on a disk drive in some bozo's desk, rather than being useful to anybody. Does the UK not have a freedom-of-information law that can be used to get a copy and post the data? I'm sure OpenStreetMap would be happy to make maps with it.
I would certainly class lead piping as a technology advance but I hadn't heard the theory that it caused the decline of the Roman Empire. Very interesting, although I should note that most of my google search results linked to refutations of the theory or downplayings of the importance of the factor.
Any other examples? My macabre side would find a certain grim glee in the idea that humans keep crippling themselves by wanting more stuff
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