How Mobile Phones Work Behind the Scenes 220
adamengst writes "We seldom think about how our mobile phones actually work, but in this TidBITS article, Rich Mogull pulls back the covers and peels away the jargon to explain why text messages work when voice calls are dropped, why your battery lasts longer in some places than in others, why you're not allowed to use phones on airplanes, why you can be notified of a voicemail message when your phone never rang, and more."
Re:wrong audience, buddy (Score:5, Interesting)
Whilst that may be a perfectly valid reason to you, the real reason is that the airlines just haven't figured out how to charge for it yet.
They will soon:
http://www.guardian.co.uk/news/blog/2008/sep/25/ryanair.mobilephones [guardian.co.uk]
which includes a classic quote from Ryanair boss Michael O'Leary:
"If you want a quiet flight, use another airline."
I don't understand this about mobile networks .. (Score:3, Interesting)
Re:Already slashdotted! (Score:5, Interesting)
And yet still cost more than an actual call...
served by a Mac (the Emperor is ill) (Score:3, Interesting)
Dual 1.33 GHz Xserve G4 - [Our server, sic]Emperor runs on a normal dual 1.33 GHz Xserve G4 (2 GB of RAM). Emperor is still running Mac OS X Server 10.2.8, which came with it and handles the load just fine, so we haven't had any reason to upgrade.
Web Crossing - The server software that powers all of our Internet services is Web Crossing, from the company of the same name. Web Crossing can do just about anything, since it backs up its built-in Web, FTP, email, and NNTP service with plug-ins that add mailing lists (also accessible via the Web and NNTP), RSS support, weblogs, wikis, and much more. A lot of this is possible becuase at its heart, Web Crossing includes a high-performance object-oriented database and not one but two programming languages for creating dynamic sites. Web Crossing is the software that Apple uses to host their discussions.
Re:wrong audience, buddy (Score:2, Interesting)
why you're not allowed to use phones on airplanes
"The Economist" explained a while back that mobile phones interfere with ground networks.
They went on to say, that if mobile phones where really dangerous for avionics, then we all would be anal-probed for the things before entering the plane, because some dickhead always forgets to turn it off.
How about "You're a loud-talking asshole and you're enclosed in a tight, cylindrical object for several hours with a couple of hundred other people who don't want to hear about your stupid business plan."
And "The Economist" also mentioned in another article, that the airlines were really afraid off riots on the plane caused by the asshole that you mentioned.
Do you work at "The Economist?"
Working link (Score:3, Interesting)
http://db.tidbits.com/article/9796?print_version=1 [tidbits.com]
Odd that the print version on the same site works.
Re:wrong audience, buddy (Score:3, Interesting)
Actually no they didn't. The plane that crashed after the passengers learned what was up didn't have reliable communication with the cell phones if the stories I recall are correct. They DID manage to get through but I do not believe that the calls were for long or that they weren't suffering from drops. It was enough though to tell folks what was going on though at least.
Re:wrong audience, buddy (Score:4, Interesting)
Providers Will Sometimes Kill Your Battery Life (Score:3, Interesting)
I heard this second-hand, so take with a grain of salt.
When a CDMA phone is idle, and the network supports it, the phone enters "slotted mode". Slotted mode is where the phone sleeps for a period of time (potentially quite long time -- several seconds), then wakes up to determine if anyone is calling it, then goes back to sleep until the next slot. Obviously, this feature is a key to very long battery life.
Apparently a certain CDMA carrier with quite sparse network capacity in the rural areas, switches off slotted mode on long weekends. They found out that when everyone goes out of town, their network can't handle it. So they force all the cell phones to drain their batteries by switching off slotted mode. They found their customers are very upset when calls do not go through, but not upset if they have a dead battery.
Sneaky if you ask me.