Engineers at a small British internet service provider have successfully made a broadband connection work over 2m (6ft 7in) of wet string. The connection reached speeds of 3.5 Mbps (megabits per second), according to the Andrews and Arnold engineer who conducted the experiment. The point of the experiment appears to have been purely to see if it was achievable.
The firm does not believe there is a way to exploit the finding. “To be honest it was a bit of fun, which one of our techies decided to try out – we have equipment we could test in the office, and why not?” Adrian Kennard, the internet provider’s director, told the BBC. “There is no commercial potential that we are aware of.”
“What it does show, though, is how adaptive ADSL really is. This can be important when it comes to faulty lines with bad (or even disconnected) joints still providing some level of broadband service.” An asymmetric digital subscriber line (ADSL) is used by nearly half of premises in the UK.
It works by splitting a single copper telephone line into separate voice and data channels. The string used in the experiment was first put in salty water – chosen because salt is a good conductor of electricity. Prof Jim Al-Khalili from the University of Surrey’s department of physics explained how it worked: “Although wet string is clearly not as good a conductor of electricity as copper wire, it’s not really about the flow of current.
“Here the string is acting as a waveguide to transmit an electromagnetic wave. And because the broadband signal in this case is very high frequency it doesn’t matter so much what the material is.” Matthew Howett, principal analyst at research firm Assembly said: “While we often get tied up in knots over whether it should be fibre to the street cabinet or fibre all the way to the home, one thing’s for certain and that’s that this isn’t going to make it into the mix of technologies companies like Openreach or Virgin Media will be using.”
Techies at UK ISP Andrews & Arnold have demonstrated that ADSL broadband can work over a wet string. An inquisitive engineer at the company this week decided to test whether wet string could work in place of twisted-pair copper for an ADSL connection. Using a two-meter (6ft 7in) length of wet string, the engineer was able to reach a downlink speed of 3.5Mbps, which is slow by today’s standards but way faster than yesteryear’s dial-up internet speeds, albeit over a short distance.
While the test was just a “fun” experiment, the engineer was testing a figure of speech probably only heard among network engineers. As the ISP’s boss explains in a blogpost, one of ADSL’s main qualities is that can adapt to function on a really poor line — so bad that it’s been said it will even work on a bit of wet string. The ‘fiber’ connection test failed using fresh water, but a second try with salty water did the trick thanks to salt’s better conductive properties.
Using a length of wet string, the engineer was able to achieve a downlink speed of 3.5Mbps.
Image: Andrews & Arnold
A pair of two-meter lengths of string were dunked into salty water and then connected side by side between two routers. Professor Jim Al-Khalili from the University of Surrey’s department of physics explained the science behind the experiment to the BBC. “Although wet string is clearly not as good a conductor of electricity as copper wire, it’s not really about the flow of current,” he said.
“Here the string is acting as a waveguide to transmit an electromagnetic wave.
And because the broadband signal in this case is very high frequency, it doesn’t matter so much what the material is.”
Previous and related coverage
Wi-Fi problems? You can boost signals with this £35 tinfoil 3D-printed reflector Researchers have created a cheap way to boost and secure your Wi-Fi network.
Scientists print mechanical objects that can communicate with Wi-Fi devices.
Read more on broadband
- ^ explains in a blogpost (www.revk.uk)
- ^ string of tweets yesterday (twitter.com)
- ^ explained the science behind the experiment (www.bbc.com)
- ^ Wi-Fi problems?
You can boost signals with this £35 tinfoil 3D-printed reflector(www.zdnet.com)
- ^ Now you can 3D-print things that connect to Wi-Fi without batteries or electronics (www.zdnet.com)
An experiment that created a 3.5 Mbps broadband internet connection won’t sound very impressive to most of us, especially since the average download speed in the US is about 75 megabits per second. But the surprising part is that it was established using a 6ft 7in piece of wet string. While broadband connections tend to rely on wires made of materials such as copper, engineers at a small British internet service provider called Andrews and Arnold wanted to see if it was possible to send data through something less conventional.
They soaked the long piece of twine in a salt water as it’s a good conductor of electricity, though it had to be re-soaked every half an hour, and used a pair of alligator clips to establish the connection. “The upkeep of these wet string connections is very hard; in our tests, we had to continually re-wet the string approximately every 30 minutes to avoid a complete loss of sync, and this process was always disruptive to the signals,” wrote Adrian Kennard, the ISP’s director, in a blog post. The entire experiment was just a bit of fun to see if such a thing was possible.
And while Kennard said it has no practical applications, it does give an idea of how adaptive asymmetric digital subscriber lines (ADSL) are. “This can be important when it comes to faulty lines with bad (or even disconnected) joints still providing some level of broadband service,” he added. Prof Jim Al-Khalili from the University of Surrey’s department of physics explained to the BBC that the experiment works as the string is acting as a waveguide to transmit an electromagnetic wave. He said that because the broadband signal is a very high frequency, the material used isn’t really important.
Share this article: