My father and I finally got our cell phones a couple of years ago. And there is something I have been wondering for the longest time now.
When you are recharging your cell phones, there is a little battery flashing in the upper corner while it is recharging (it might be different with other cell phones). Thus while you are recharging, the cell phone is clearly in recharging mode. Does your cell phone company receive a signal from your cell phone telling them you are recharging it? In other words, do they know whenever you are recharging it? After all they know when you have your cell phone on, don’t they?
No they don’t. If your cell phone is on it will emit a locator signal every so often - this will tell the cell-phone service where you are, by locating the nearest service broadcast beacon.
If your phone is off it won’t broadcast anything and the company has no idea where you are or what you’re doing. If you recharge with your phone on, the cell phone just gives out the same locator signal - so the company can direct calls to you. No extra info is broadcast if you are recharging, hence the company no nothing extra.
The flashing battery icon (or whatever your phone displays) is just to let you know that your phone is not finished recharging. When it is finished, the icon will not flash any more…
There’s no technical reason a phone couldn’t say it’s charging when it send out the periodic “Hey, I’m over here!” locator signal. Would just take one more bit in the datastream - 1=charging, 0=not charging. A fancy phone could use two bits, with the extra to say it’s on a home charger or on a car charger.
But why would the cellular service care? Thery’re certainly not going to give you credit on the bill for keeping the battery fully-charged. Their computers are busy enough with calculating how to get away with adding a minute to each call to more rapidly deplete your montlhy allowance. :dubious:
Even if the service provider cared and the phone was transmitting such information, that’s not necessarily enough. In most cases, the manufacturers of the phones are different organisations from the network operators. To get things to work at all, the industry can’t rely on things being sorted out on a one-by-one basis between these two sides, particularly once you’re considering systems that are meant to be used in multiple countries. The solution is to have standards organisations solicit input on how the systems will work and then produce a specification that everybody has to adhere to. Basically, the specification mandates what the transmitted signal has to be. Most of what the phone’s sending out is thus tightly constrained. The advantage is that the receiver (here a basestation) can assume lots of stuff about the signal in decoding it. And, unless the feature is supported in the spec, one of those assumptions in most receivers is that the recharging information isn’t being sent.
You can try to subvert the spec, but that’s not a good idea in general.
The question is then whether the standards authorities support a recharging alert feature. Can’t say in general, but at least as far as CDMA is concerned, I’m fairly sure the 3GPP don’t.
