Democratic Underground Latest Greatest Lobby Journals Search Options Help Login
Google

How come cell phones don't have dial tones?

Printer-friendly format Printer-friendly format
Printer-friendly format Email this thread to a friend
Printer-friendly format Bookmark this thread
This topic is archived.
Home » Discuss » The DU Lounge Donate to DU
 
underpants Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 11:56 AM
Original message
How come cell phones don't have dial tones?
Are dial tones to be a thing of the past some time soon?

Just wondering.
Printer Friendly | Permalink |  | Top
kay1864 Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:05 PM
Response to Original message
1. Dunno for sure, but I'm guessing it's because
with a landline phone, it's either working or it's not. With a cell phone, your signal strength varies, which a dial tone wouldn't tell you very well.

Plus with a cell, it was designed that you hit Send after you've dialed the number. I'm guessing that design was b/c it's easier to misdial with a cell, so you're supposed to look at the number you entered.
Printer Friendly | Permalink |  | Top
 
LaraMN Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:06 PM
Response to Original message
2. More importantly,
who's the weirdo who keeps texting me, "who this?"
Printer Friendly | Permalink |  | Top
 
underpants Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:08 PM
Response to Reply #2
3. Good question
and yet still we have no answers
Printer Friendly | Permalink |  | Top
 
LaraMN Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:10 PM
Response to Reply #3
4. Yeah- or the one who sent me
Edited on Mon Oct-30-06 12:10 PM by LaraMN
a "love-o-gram" at my school email addy.
I thought it was my husband.
Wrong.

:scared:
Printer Friendly | Permalink |  | Top
 
Deja Q Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:11 PM
Response to Original message
5. I'm hum in your ear when you whip out your big cell phone...
Will that help? O8)

Printer Friendly | Permalink |  | Top
 
tigereye Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:13 PM
Response to Original message
6. aren't dial tones a function of the old-school phone company
and it's hardware?

I would guess that cell phones aren't part of that, hence no dial tones.


Interesting question...
Printer Friendly | Permalink |  | Top
 
underpants Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:19 PM
Response to Reply #6
7. That's why I am here
ACtually now that you mention it (this comes from WAY back in the catacombs of the mind) I saw a guy with a tape recorder on TV a long time ago dialing a phone by playing a recording of the dialed numbers into the handset. Apparently phones just listen for the sound of each number and call from there. Okay maybe that isn't correct but it was fun while it lasted.
Printer Friendly | Permalink |  | Top
 
Solon Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:33 PM
Response to Reply #7
9. You're referring to Phreaking...
He wasn't dialing in the numbers, but rather the change for a public payphone. Payphones, if you listen while you insert change, make a series of beeps depending on the coin you insert into the phone. There's a sound for a Quarter, a Nickle, and a Dime. Anyways, you can record these tones, and play them back through the mouthpiece, and basically call anyone around the world for free. Granted, this depends on the quality of the recording/playback device, dictation machines suck, MP3 players are perfect, you can download the tones, and they are high quality.

The only problem is this, its illegal, and it best works on older phone systems. Nowadays, its almost impossible to do this technique, used to work in the past, but with digital switching, etc. its becoming much harder.
Printer Friendly | Permalink |  | Top
 
madinmaryland Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 12:21 PM
Response to Original message
8. It is a function of the telephone companies.
Basically it was a low voltage sent over the lines, which produces the the dial-tone hum you are familiar with. This was a quick way to tell if you had connectivity to the Central Office.

With cell-phone you can't send transmit in this fassion. To check for connectivity, most cell-phone indicate if they are receiving a signal via a bar-graph.
Printer Friendly | Permalink |  | Top
 
BigMcLargehuge Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-30-06 03:05 PM
Response to Original message
10. I can answer this!
Direct Connection between Home and Central Office

Dial tone is a service delivered over copper landlines from the Telco Central Office (CO). Dial Tone is a "switch based service". Modern wired phone systems routinely use both digital transmission and a mix of copper and fiber infrastructure so the act of "receiving dial tone" is a little different than in the past age of analog telephony. Modern dial tone over a wired system uses a series of digital signals to inform the switch that the telephone (station) is off-hook. These signals are carried "out of band" in the D-Channel in L-DAP/ISDN based implementation and "in-band" in DSL and FDM implementations.

Digital stations receive a "play dial tone" code from the CO rather than direct current from the CO in a digital system.

Indirect Connection between Home and Central Office via a Remote Digital Terminal

Signals are carried in analog format to the Remote Terminal (RT), where the actual request for service signal is sent on to the CO. However many manufacturers of Remote Terminal equipment make dial tone provision a feature of their products. Thus, receiving dial tone from the RT is the same as it would be if you were receiving dial tone from the CO itself.

Indirect Connection between Home and Central Office via Fiber to the Premesis/B-PON architecture

In Fiber To The Premesis implementations the request for dial tone is converted into a digital optical signal at the pump laser attached to the Terminal Box attached to the side of your house. And the battery in the Terminal Box equipment sends the low voltage signal to the station.

Connection between a Mobile Handset and the Base Station

Wireless networks, such as PCS or Digital Cellular do not maintain a physical connection to the switching offices (known as MCDs in Wireless). Instead of going "off-hook" like a landline phone, the handset powers up and begin exchanging messages with the base station over the control channel. These messages set up the connection between the handset and the MCD. Connection is signaled visually in CDMA systems, and both visually and with dial tone in TDMA systems (since TDMA systems use a specifically assigned timeslot within a channel for upstream and downstream traffic)
Printer Friendly | Permalink |  | Top
 
DU AdBot (1000+ posts) Click to send private message to this author Click to view 
this author's profile Click to add 
this author to your buddy list Click to add 
this author to your Ignore list Wed Jul 30th 2014, 05:24 PM
Response to Original message
Advertisements [?]
 Top

Home » Discuss » The DU Lounge Donate to DU

Powered by DCForum+ Version 1.1 Copyright 1997-2002 DCScripts.com
Software has been extensively modified by the DU administrators


Important Notices: By participating on this discussion board, visitors agree to abide by the rules outlined on our Rules page. Messages posted on the Democratic Underground Discussion Forums are the opinions of the individuals who post them, and do not necessarily represent the opinions of Democratic Underground, LLC.

Home  |  Discussion Forums  |  Journals |  Store  |  Donate

About DU  |  Contact Us  |  Privacy Policy

Got a message for Democratic Underground? Click here to send us a message.

© 2001 - 2011 Democratic Underground, LLC