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hakermania
June 5th, 2012, 02:00 PM
Ok, ok, don't call me stupid, it's just something random that came to my mind, I know that I am not the first one to think this (I've never heard of it before but, apparently, I am not the first one) but I don't know why something like this isn't being implemented!

Ok, think a bit the below things:
We have mobile phone A and mobile phone B, and phone A wants to call phone B.
So, phone A communicates with the center which tracks phone B. The center establishes the connection between the two phones and phone B rings. For this connection type to take place, both phone A and B communicate with the center by sending and receiving data. Also, phone A and B can be several kilometers away from the center and the connection will still be successful.
This means that mobile phones are capable of sending and receiving data from far far away, so, to the point now, why are we unable to make phone calls directly, phone-to-phone when phone A and B are close (some kilometers) to each other? Why there should always be a center in the middle of this communication type?

Wouldn't it be possible phones to have 2 modes, one for close calls and one for normal calls, just like the ones we know nowadays? I know that this pretty reminds walkie-talkies, but, why not? Who wouldn't like free calls? And, anyway, I bet that 60% of your total calls from your mobile are with persons no more than 10 kilometers away from you!


Thanks for any answers and sorry if this sounds very stupid :D

CrocoDuck
June 5th, 2012, 02:30 PM
Hi. Dunno how cell phones works in detail, but you know, isn't like walkie talkie. Walkie talkies (most of them) send analog signals and the information is given by modulating a sinusoidal wave of selected frequency. Another walkie talkie can receive your signal basing his receiver on risonance. Thus, everyone who has a receiver that works on that frequency can hear you (like radios). You see that things comes complicated if we have to menage nowadays traffic. For digital things is different, first of all because the signal is converted in bits. Also you make sure, with digital electronics and programs, that only the devices you want can exchange datas (dunno how). So for cellphones you need a lot of calculating for mange all the traffic that you want to pass trought your device. So you need centers that compute for you and the others gazillion devices.

Sorry for my bad english, hope i didn't write too much wrong things.

hakermania
June 5th, 2012, 02:42 PM
Hi. Dunno how cell phones works in detail, but you know, isn't like walkie talkie. Walkie talkies (most of them) send analog signals and the information is given by modulating a sinusoidal wave of selected frequency. Another walkie talkie can receive your signal basing his receiver on risonance. Thus, everyone who has a receiver that works on that frequency can hear you (like radios). You see that things comes complicated if we have to menage nowadays traffic. For digital things is different, first of all because the signal is converted in bits. Also you make sure, with digital electronics and programs, that only the devices you want can exchange datas (dunno how). So for cellphones you need a lot of calculating for mange all the traffic that you want to pass trought your device. So you need centers that compute for you and the others gazillion devices.

Sorry for my bad english, hope i didn't write too much wrong things.

Yes, I didn't actually said that mobile phones can work as walkie-talkies, but I questioned whether they can do something similar.

So, the answer is that the main problem is that there have to be done many calculations in order for this to work and mobile phones don't have the power for this?

CrocoDuck
June 5th, 2012, 02:56 PM
Yes... I think. Of course, maybe I'm wrong and I did not understand anything of cellphones tecnology (and/or analog too...)... But lefting even local traffic on the shoulders of isolated devices looks hard. Sorry for talking about analog devices, was just to frame the problem.

hakermania
June 5th, 2012, 02:59 PM
Yes... I think. Of course, maybe I'm wrong and I did not understand anything of cellphones tecnology (and/or analog too...)... But lefting even local traffic on the shoulders of isolated devices looks hard. Sorry for talking about analog devices, was just to frame the problem.

Well, then I guess that I have to expect someone more experienced to answer...
In my mind, the communication via the center was done with the sole purpose of calculating the speaking time so as to apply the corresponding fees!

HermanAB
June 5th, 2012, 07:12 PM
Some cell phones can actually do that. In some places it is known as Press To Talk. Old hat really and not much in demand.

hakermania
June 5th, 2012, 07:21 PM
Some cell phones can actually do that. In some places it is known as Press To Talk. Old hat really and not much in demand.

Why not much in demand? Which phones do they do it? I am asking because I (in my situation right now) could reduce the cost of my phone almost 100%!!!

skellat
June 5th, 2012, 09:59 PM
Ok, ok, don't call me stupid, it's just something random that came to my mind, I know that I am not the first one to think this (I've never heard of it before but, apparently, I am not the first one) but I don't know why something like this isn't being implemented!

Ok, think a bit the below things:
We have mobile phone A and mobile phone B, and phone A wants to call phone B.
So, phone A communicates with the center which tracks phone B. The center establishes the connection between the two phones and phone B rings. For this connection type to take place, both phone A and B communicate with the center by sending and receiving data. Also, phone A and B can be several kilometers away from the center and the connection will still be successful.
This means that mobile phones are capable of sending and receiving data from far far away, so, to the point now, why are we unable to make phone calls directly, phone-to-phone when phone A and B are close (some kilometers) to each other? Why there should always be a center in the middle of this communication type?

Wouldn't it be possible phones to have 2 modes, one for close calls and one for normal calls, just like the ones we know nowadays? I know that this pretty reminds walkie-talkies, but, why not? Who wouldn't like free calls? And, anyway, I bet that 60% of your total calls from your mobile are with persons no more than 10 kilometers away from you!


Thanks for any answers and sorry if this sounds very stupid :D

It does appear that you're thinking about the iDEN which was available on Nextel here in the United States. Wikipedia has an interesting round-up here (http://en.wikipedia.org/w/index.php?title=Integrated_Digital_Enhanced_Networ k&oldid=495132486).

Smilax
June 5th, 2012, 11:44 PM
Some cell phones can actually do that. In some places it is known as Press To Talk. Old hat really and not much in demand.


true, i saw this stuff in oz/new zealand when i was doing some farming some 10 years ago.

works great if there is a bunch of workers on the same patch of earth.

hakermania
June 6th, 2012, 08:32 AM
Can we expect this technology to be more used in the future?
Or the benefits of the Companies are too many and they don't want it??

shaikzubair
June 6th, 2012, 08:46 AM
When phone A dials number the Center looks in its records the address of phone B like
1. what was the last location he received calls and then
2. his home zone/ office location.


You cannot store all these information in the mobile phone also its much faster if someone looks for you.

The walkie talkie on the other hand uses a fixed frequency with a fixed channel and only one person can use it.


Can we expect this technology to be more used in the future?Absolutely not, It is difficult to make such a device even if it does then it wont be small and mobile anymore and the companies such as NOKIA, SAMSUNG etc wont let you do it.

lisati
June 6th, 2012, 08:57 AM
Some cell phones can actually do that. In some places it is known as Press To Talk. Old hat really and not much in demand.


true, i saw this stuff in oz/new zealand when i was doing some farming some 10 years ago.

works great if there is a bunch of workers on the same patch of earth.

Mrs Lisati and I have phones with the Press To Talk feature. We don't use it: one of the phones got lost, damaged, returned and subsequently replaced, and the other was misplaced, replaced and found. I don't see a point in getting them working again, as they're both CDMA phones, and our local CDMA mobile network is being turned off at the end of next month.

3rdalbum
June 6th, 2012, 09:13 AM
I don't see that it has much use, really. For $40 a month I can call anyone in the whole country, an unlimited number of times, for unlimited number of minutes, without having to pay anything more. They don't have to be within mobile phone range (which, BTW, is a LOT less than 10km)

You can't do conference calls like on a walkie-talkie, and you must still be within range of a tower - that's the only disadvantage of the unlimited phone plan.

Your other option is called Batphone, and it's a way of doing walkie-talkie-like communications with phones using an ad-hoc wifi network. It's made for emergency workers in disaster zones, but I think they'd just still use their existing equipment rather than a buy bunch of smartphones.

forrestcupp
June 6th, 2012, 05:37 PM
Why not much in demand? Which phones do they do it? I am asking because I (in my situation right now) could reduce the cost of my phone almost 100%!!!


Can we expect this technology to be more used in the future?
Or the benefits of the Companies are too many and they don't want it??No. Push-to-talk royally sucked. It's been done, and it sucked so bad that it has kind of disappeared. You didn't actually have to be near someone to use that feature. It just made your phone like a walkie talkie, where you push a button on the side, and you could talk and hear through your phone like a walkie. The quality was horrible, and it was kind of obtrusive to not know when someone was just going to start talking to you out of the blue.


When phone A dials number the Center looks in its records the address of phone B like
1. what was the last location he received calls and then
2. his home zone/ office location.


You cannot store all these information in the mobile phone also its much faster if someone looks for you.

The walkie talkie on the other hand uses a fixed frequency with a fixed channel and only one person can use it.

Absolutely not, It is difficult to make such a device even if it does then it wont be small and mobile anymore and the companies such as NOKIA, SAMSUNG etc wont let you do it.This is why the OP's suggestion won't work. The central location that your calls go through is not just a transmitting station. It's also like a switch board that routes your calls to the right phones. Your phone can send and receive signals, but there's no way it could act as a switchboard to determine where to route the call.

The best that would be possible is the Push-to-Talk feature, which has already been done, and it sucks. ;)