56 posts • joined 13 Nov 2011
Re: And how the hell is there an electrical current in fibre optic lines?
Power feeding is the answer you are looking for.
There are optical amplifiers fitted to each fibre every 60~70km which require DC power to operate (50V per amplifier), so a positive voltage is fed from one end and negative from the other - a long cable may have 25kV or more applied across its ends. The power is carried by the copper tube surrounding the fibres. This tube is interrupted at each amplifier with 50V being dropped across each of the series connected amps - kind of like xmas tree lights.
One of the interesting side effects of this is that somewhere near the mid-point of the cable the voltage on the power conductor is zero relative to the seawater outside the cable. This means that if a shark or other agency does expose the conductor to sea it is sometimes possible to move the zero volts point by adjusting the power feeding voltage at each end. This stops (or minimizes) current leakage at the fault point, allows the cable to keep working until a repair ship is on-site and reduces galvanic erosion of the copper tube at the fault point, which can ruin km of otherwise good cable in fairly short order.
Unamplified (hence no power feed) cables are possible - personally I've worked on one of 235km - but require the use of Raman pumps at the end points and are likely to have capacity restrictions due to signal to noise compromises imposed by the lack of intermediate amplification. My understanding is that the maximum length for this type of installation is under 400km.
Sorry, no I wasn't there on the Apollo mission - just work for a company that does submarine cables amongst other things.
I don't think so.
So what they've actually developed is a coffee capsule machine that works in zero gravity - not really got a lot to do with espresso, quality or otherwise, has it?
"Sorry, voice just isn't there. It wasn't there 20 years ago, it's not there now."
How true - I fully agree with you, no-one should put any R&D effort into anything until it's been fully perfected.
Meanwhile, here in NZ
"...you will never find a native Australian cockroach in your home - "
That's all very well in Australia, but here in NZ I have a constant stream of large Australia cockroachs parading through the house - big sods, with a yellow stripe down each side - from Western Oz I believe.
Re: Get a life...
"Feet and fathoms are much better than metres for nautical (and aviation) purposes."
Back in the days when I could still afford flying lessons, I seem to remember that weight was in measured in kilograms, visibility was measured in metres and kilometres, height was in feet and fuel and oil quantities were in US gallons and quarts (Cessna 152).
I seem to recollect a number of years ago that a commercial flight in the US, using one of Boeing's fine products, had to make an emergency landing because one of the pilots had mistakenly assumed the recorded fuel load was in Kg, whereas it was actually in pounds.
Incredible as it may seem, given the stakes involved, aviation appears to be the one field of human endeavor that attempts to cater for all measuring system preferences.
Re: Good while it lasted
Ye gods! - what sort of a backward system do you have over there?
When I changed from Vodafone to Telecom NZ last year I signed the paper work at lunch time and my new phone was up and running by 10 that night (and it wasn't my job to seek any sort of code from VF, either) - you've still got all of Friday to get that number ported, should be more than enough time.
They just need to release some pythons into the area.
I was able to see a Mosquito in the air during an Armistice Day fly-past in Nov., 2012 - an impressive aircraft, but for my money the best looking aircraft of WW2 would be the ME262.
The world's first operational combat jet, the only jet to see squadron service during the war, and as an additional plus it had a healthy speed advantage of the Mosquito, which would have probably seen the Mosquito become just another old aircraft if the war had continued.
Or you can root your device and sort the mess out yourself.
Running Android 4.3.1 (KatKiss 028 ROM) with Apps Advanced Permissons control, Adblocker to sort out those pesky ad-funded apps and Droidwall to sort any app that thinks it knows better than myself who gets to access the net from my tablet.
I once read a book on the subject of commercial whaling, back in the days when real men stuck a sharp stick into the whale from a rowboat and then held on to the string with a firm grip.
It seems that sometimes the whale got away, only to die later from the wounds and, if it felt so inclined, at this point it would float around on the surface - often for many days. Occasionally a whaling ship would come across one of these 'stinkers', as they were known, and haul it in to reap someone else's just rewards.
The phenomena of a stinker exploding when poked at carelessly with a flensing knife was not exactly unknown, but it appears the crews were normally just too busy at the time to video it and post on Youtube.
Re: Easy fix.
You do realise that there are repositories of legitimate Android apps other than the Play store, don't you? - or perhaps not.
This isn't an Apple-like situation, where there is only one source allowed - downloading apps from somewhere other than Play doesn't automatically place an individual in the " retards that "shop" for warez" category.
Re: A neat trick
Not necessarily true - last week I got a new phone.
On free phone plan, phone = $0, contract = 24 months x $49.00, total cost = $1176.00.
Buy phone outright = $299.00, same calling plan over 24 months @ $39.00/month, total cost = $1235.00.
Conclusion: do the maths - sometimes the obvious answer is not the correct one.
"Make it so"
I suspect that the phrase that so many associate with Captain Picard, "Make it so", doesn't actually originate with Star Trek TNG.
The author Patrick O'Brian (1914~2000) puts it into the mouth of his Napoleonic era character, Royal Navy captain Jack Aubrey. The historical detail in the books of this series appears to be well researched, so I'm going to suggest the the writers of Star Trek adopted this from RN tradition, rather than inventing it.
@ J G Harston
FFS! - did you even bother reading the article?
Repeat after me - "The student's issues have nothing what so ever to do with Apple, who are just one of their employer's many clients."
Re James 51
"Do submarine optical cables have repeaters? I can see how land based systems could be upgraded to take advantage of this but there might be a bit of a lag in adding it to global networks."
Modern submarine cables have analogue amplifiers as their submerged plant - they are protocol agnostic and so long as the signal fits within the amplifier's gain band they will work.
What this means is that in order to increase a cable's capacity you just need to replace the landing station equipment - and if you're lucky this might mean no more than replacing a transponder with a higher capacity one working on the same grid spacing (50GHz between lambdas) eg., replace a 2.5Gb/s transponder with a 10, 40 or 100Gb/s one.
@ Oliver Jones
"This won't stop with Cyprus, either - New Zealand is already considering taking similar action, and you can bet more countries will follow - especially when they can justify prior usage - and yet the frog still doesn't leap from the boiling water to save himself."
No NZ is not considering taking similar action - what is being considered is the possibility of putting legislation in place that would allow the action to be taken as a last resort should it ever be required - not quite the same thing.
Please do you research
The Alcatel One Touch brand is owned by TCL Communications - it is not part of the Alcatel-Lucent group.
Yep - works for me - and it'll work for my wife too, once her Nexus 7 is out of warranty and rooted.
Re: You still have landlines in England???
"But, yeah, "I ain't Spartacus" we had the same when I was a kid, about 50 years ago. I seem to remember having to press a button on the top of the phone for some reason to make a call...Often picked up to hear the other party talking."
If memory serves me correctly, what you had there was specifically an "R-party" line - two subscribers per line, each of whom obtained dial tone by pressing the button, which placed an earth on one leg of the line to obtain dial tone. The call was then held by the loop in the normal manner.
By ensuring each party drew dial tone by earthing a different leg of the line it was possible for the exchange equipment to determine which of the two subscribers had initiated the call, ie., each party on the line had their own line circuit relays in the exchange - this allowed automatic metering for the call to take place.
I think (conventional) ringing was applied one leg to earth, so you only heard ringing for calls directed to you.
The other party line type was the "M-party" line - 5 or 10 subscribers per line, dial tone pulled by a loop on the line, a single line circuit so no identification of who the call was initiated by, coded rings (morse coded letters) and every subscriber received every ring.
It's been a while (40 years last December) and those days seem a long time ago - but yesterday a 40 year service award fronted up on my desk, so I guess I'm luckier than most of the people I started with back in '72.
The tricky part
I can see one potential problem with this whole scheme - when does ownership pass to the end user when you buy a cell phone on contract?
Obviously there is the potential for each country to have its own rules about this, but I can see that if ownership remains with the service provider until the contract is completed and the subsidy repaid (a common sense idea?) then the pawnbroker is potentially not holding any form of security for the loan at all.
Re: Don't buy locked phones....
Actually, as far as I'm aware here in New Zealand any phone you buy is unlocked, even if it is on a subsidized contract - although personally I've always bought from non-carrier sources so I can't confirm that for sure.
Interestingly enough a friend has recently bought an unlocked, AT&T branded, Samsung from some on-line source.
Re: "West Island"?
Stop complaining - many NZers consider there are three islands making up our country - North Island, South Island and Mouth Island.
Not only has this been done on some small islands off the coast of New Zealand, but just a few km from where I live there is an "inland island" - part of a mountain which has been surrounded with a predator proof fence and all introduced mammals within the area have been eliminated - rats, cats, stoats, goats, possums, pigs, dogs, etc. - in fact the only remaining mammals in the area should be two very small bats.
This area has recently had kiwi and other ground dwelling birds reintroduced to it - it can be done.
The problem with impedance matching
It's all very well to match the impedance of an antenna to a radio's input/output stages, but anything less than a resonant antenna of the correct length for the frequency in use will waste power in the matching system.
I can easily match the output of my 100W HF transmitter to one of my VHF whip antennas, but all I'm likely to get for my efforts is a hot antenna tuning unit.
If only we could
"you would have to kill every hedgehog, rabbit"
That way we'd only be left with wild goats, wild pigs, wild deer, stoats, possums and a few other small mammals to eliminate from the wild, after which our native bird life might start to recover.
Mine's the one with two small bats and no other mammals in the pocket.
"That means you could plonk them down on a Kiwi bar and demand a nice cold Tui* in return. You'd be mad to do so, however, as the coins sell for well above their face value."
If you're daft enough to order a Tui then you'd probably be daft enough to buy these coins - most beers produced by NZ's two big brewing companies are flavourless crap, probably because the use of hops and malt in their makeup has been cut to the absolute minimum.
Re: Dave 126
"I'm with you, Conel... RP was my dissertation subject more than ten years ago, and I still can't think of a convincing end-use that justifies the hype it has attracted in the last few years (with no real advance in technology).
Objects are usually better if mass produced (the tolerances of injection-moulded parts are incredible) and if you want to customise an object for a person (a hearing-aid, for example) taking a direct cast of the body part is usually the better option."
What I'm thinking of is a combination of the two - some have commented on how fast their dentist can produce a new crown - what I'm hoping for is a complete 'while you wait' set of new gnashers, rather than having to wait a week or so and make repeated visits.
What about the rights of
those of us who live in countries where prostitution is legal - shouldn't we be able to access an app that makes it easier for us to locate businesses we want to deal with?
"But using a physical USB connector for supplying a non-standard voltage and current is just asking for trouble."
Not really - the PSU supplied with the Asus Transformer range of tablets has a USB 3 socket on the wall wart - if it detects a Transformer it supplies 15V, fails to detect a Transformer the same socket supplies 5V.
The only trap for young players is that if you want to insert a USB extension lead in the middle it needs to be a USB 3 cable to support the Transformer detection process, otherwise you just get 5V out.
"If you really want to terrify yourself look up Single Wire Earth Return for mains power distribution. I lost patience looking up what I am sure is the same technique used for early submarine telegraph cables, which I am sure used one conductor and an earth return. "
Power feeding for submarine cables is still done this way - DC positive fed from one landing station, negative DC from the other end of the cable and the cct completed via earth.
@ Chris Miller
"I can't think of the incident you describe, but I can easily think of two recent incidents (the landing in the Hudson and the BA 777 into Heathrow) where the presence of a human pilot led to the survival of all on board, when pure automatics would undoubtedly have left everyone dead."
It's even easier to think of a much bigger number of incidents where the presence of a human pilot, particularly one who refused to believe what their instruments were telling them, has lead to the unnecessary deaths of all on board.
Re: Monday, US time
"Is that like Tuesday everywhere else?"
Certainly would be where I live - for most of the day, anyway.
Re: £22 K?
Having early this morning had the opportunity to observe at first hand exactly how much wee a 7 week old kitten can contain, I have every confidence that an 11 year old child could quite easily contain enough to destroy an entire container load of laptops if he so desired.
Re: I'd give anything to go back to Honeycomb
"Mines fine, but then I'm running the official Asus update, not some romantic from XDA with added extra sauce/spyware."
I'm running the official version too - but it doesn't alter the fact that many people (including myself) are experiencing issues such as random reboots, shutdowns and the inability for the device to have an uptime greater than 72 hours.
I suggest you actually go and read some of the relevant forums before making uneducated guesses as to what the actual situation might be.
Re: Could someone explain to me...
The wire doesn't necessarily have to be thicker - the same overall diameter of high strand count cable could achieve the same lowering of resistance as a thicker wire with fewer strands.
It's a 1/R(total) = 1/R1+1/R2+ ......... +1/Rn thing.
An unsuspecting child
The most likely thing for a child, either unsuspecting or suspecting, to be hit from above by is a chuck of 'blue ice', should they be foolish enough to be playing outside under the approach path at most of the world's airports.
And the impact on Foxconn will be?
Foxconn is a Taiwanese company, not a Chinese one - if all the publicity results in electronics assembly becoming uneconomic in China, Foxconn are perfectly free to open plants in the Phillipines (or any other country) to carry out the work.
Re: There's nothing new here
Attenuation can be overcome with amplifiers - the noise introduced by the amplifiers and the fibre itself is a limiting factor though - as are Chromatic Dispertion (can be compensated for at terminals), Polarisation Mode Dispertion (can be compensated for at terminals), non-linear effects as channel count (and hence launch power) increase eg., SBS, inter-channel modulation effects, Raman Scattering.
You've never worked on any system that uses EDFAs, have you?
The amplifier pump lasers are slightly more sophisticated than a "green LED light" and the amplification is by no means "noiseless" - or so says the Alcatel-Lucent DWDM technical manuals I'm looking at, but hey, what would they know about it compared to you?
Never mind the fancy name -
why not focus on making it work properly?
So far I am considerably unimpressed with the stability of ICS.
Re: 650 feet is shallow waters?
The record for retrieving and repairing a cable is from a depth of 10km - work out how much trailing rope that would take, and then contemplate the difficulty of finding and cutting the cable initially, and then having to hook and retrieve each side of the cut to effect the repair.
A waterproof, floating, phone has its uses - my daughter-in-law has a habit of dropping her phone when entering and leaving home, which is an expensive hobby when you live on a boat.
@ Next the Terrorist crazy USA will be demanding their extradition
"Perhaps these guys have inadvertently discovered a chink in the American security fence that protects it from real or imagined terrorists. What a hoot, that should make the Pentagon start a whole new multi-billion dollar program to detect and eliminate meteorological balloons."
Been done, I think you'll find, by the Japanese during WW2 - sending balloons to drop explosives on the US, that is.
@ Levente Szileszky
Your ravings might make more sense if it wasn't for the fact that Adobe have announced that the version of Flash they produced for Android ICS is the end - the next version of Android will not have Flash either.
"Yes, that is my hat and coat. Why do you a..oh, you want me to take it and leave, got it"
Only if you're in NZ - if you're in Oz they will have been stolen by now anyway, so just focus on the leaving part.
The essential difference between NZ and OZ is that being a Kiwi my ancestors actually bought tickets to get here, as opposed to being given a free overseas holiday.
"Busses will be quicker to board! But, not usable by visitors, tourists or casual users that might feel like taking the bus instead of using their car. Oh and big brother will no where everyone has been."
I have contactless passes for buses in 3 different cities, only one of which I live in and use buses regularly.
The passes in the other two (and my home city) were cheap and easy to obtain for casual use, and in no case was I asked for any personal details when getting the pass - give us some money, here's your pass, enjoy. Big brother knows where the passes go, they have no idea who is using the pass.
Charity begins at home
It would be a good start if Google used this money to sort out the slavery conditions under which undocumented migrants labour in the southern US before sticking their noses into other countries.
At least with Apple products it's fairly easy to kill the kill switch - just jailbreak and modify the hosts file to stop it happening.
@ I Call BS
No, even normal beer is about 95% water, I'd hate to thick how little alcohol is in Coors Light - and normal beer will happily freeze in a domestic freezer.
So, how many of these tethered bugs will be required to power a medium sized town?
- JLaw, Kate Upton exposed in celeb nude pics hack
- Google flushes out users of old browsers by serving up CLUNKY, AGED version of search
- China: You, Microsoft. Office-Windows 'compatibility'. You have 20 days to explain
- GCHQ protesters stick it to British spooks ... by drinking urine
- Twitter declines to deny JLaw tweet scrubdown after alleged iCloud NAKED PHOTOS hack