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5. GSM

GSM Features That Aren't Widely Known

I don't think anyone deliberately withheld this information from us, I think they just didn't think of it when they put together their information packages. The following are standard GSM codes and procedures, so you aren't learning anything "Top Secret" here. Just the same, you might find this information extremely valuable.

SMS Delivery Reports

As many of you know, GSM is the only technology that supports the SENDING of SMS from the handset. You can use this feature to send SMS to another handset, or to a gateway. But how do you find out if the person you sent the message to has picked it up? On the menu of most GSM phones you'll find an option for "Delivery Reports", but this doesn't seem to work on Microcell Connexions in Canada, nor on some other GSM networks in North America.

But here's something that DOES WORK. Add a string of three 1's to the beginning of your message, something like this:

111Hi Joe, are you coming to the meeting?

Your recipient won't get the "111" at the beginning of the message, but you will be sent a confirmation message immediately after your recipient's phone downloads the message from the switch. This doesn't guarantee he's read your message, but it does guarantee that it is now IN his phone. If the message "goes stale" and is deleted from the carrier's system before it is picked up, you will also receive a confirmation of this.

I can't guarantee this will work on ALL GSM networks, but it should.

Call Forwarding

GSM supports FOUR types of Call Forwarding:

Forward All Calls: This mode forwards each and every call that comes into your GSM number, unconditionally. This is what most people traditionally think of when you mention call forwarding.

Forward if Busy: This mode forwards calls that come into you GSM number when your phone is busy. This means that instead of getting a busy signal, the caller is deflected to a different phone number.

Forward if Not Answered: This mode forwards calls that come into your GSM number when you fail to answer them. This normally occurs after 15 seconds, but you can change this duration (as you will see later).

Forward if Out of Reach: This mode forwards calls that come into your GSM number when your phone is either turned off, or out of the service area (showing No Service).

Each of these four modes operate independently of the others, which means you can set a completely different number for each, or choose to forward under some circumstances and not others. Most people choose to set Forward if Out of Reach to their Voice Mail, thus insuring that calls go there when the phone is off or out of the service area.

To turn your phone into a pager, you need only Forward All Calls to your Voice Mail, but leave the phone switched on. No one can call you, since their calls go directly to the Voice Mail, but once a message has been left, the phone will still beep to inform you of this fact. Numeric and Text Messages also arrive uninterrupted.

And did you know that you don't have to use the menu options to set, clear, or check these four forwarding options? The following is a list of the strings you can type into your phone to to access these features. After typing in the string, press the TALK button.

Forward All Calls
- Activate
- Cancel & De-register
- Cancel & Retain
- Status
- Re-establish
*21*[Phone Number]#
##21#
#21#
*#21#
*21#
Forward if Busy
- Activate
- Cancel & De-register
- Cancel & Retain
- Status
- Re-establish
*67*[Phone Number]#
##67#
#67#
*#67#
*67#
Forward if Not Answered
- Activate
- Cancel & De-register
- Cancel & Retain
- Status
- Re-establish
*61*[Phone Number]#
##61#
#61#
*#61#
*61#
Forward if Out of Reach
- Activate
- Cancel & De-register
- Cancel & Retain
- Status
- Re-establish
*62*[Phone Number]
##62#
#62#
*#62#
*62#
Simultaneously perform ALL
FOUR forwards:
- Activate
- Cancel & De-register
- Cancel & Retain
- Re-establish

*002*[Phone Number]#
##002#
#002#
*002#
Simultaneously perform ALL
Conditional Forwards:
- Activate
- Cancel & De-register
- Cancel & Retain
- Re-establish

*004*[Phone Number]#
##004#
#004#
*004#

For example, to forward calls to 416-867-5309 when you are out of reach, you enter:

*62*4168675309#

Note: The cancellation feature actually has TWO different modes of operation. By prefacing the operation with two pound symbols instead of one, you instruct the network not only to cancel the forwarding operation, but to completely de-register this service. So what's the difference? If you use just a single pound symbol, this does turn off the selected call forwarding option, but the network retains a memory of the last number used. This allows you to turn the forwarding option back on, with the same number as before, by simply entering the "Re-establish" code noted in the chart. Re-establish will FAIL if you try to use it after performing a "Cancel & De-register" operation.

Being able to enter these functions as strings means you can store them in memory locations and speed-dial them whenever you need to. Be careful when attempting to set or clear Forward if Busy, Forward if Not Answered,. and Forward if Out of Reach, as these features will NOT change if you presently have Forward All Calls active. Turn off this latter feature first, or you may receive a "Not Done" error message from the network.

Earlier I said that you could set how long the network would wait before assuming you had not answered your phone. To do this, use the following string to activate Forward if Not Answered (it cannot be done from the menus):

*61*[Phone Number]*11*[Time]#

For example, to forward to 416-867-5309 after allowing your phone to ring for 25 seconds, you would enter:

*61*4168675309*11*25#

The Time parameter may be 5, 10, 15, 20, 25, or 30. These are the only valid entries you may use. The "11" in this code refers to "Voice Calls", but since Fido only handles voice calls at this time, there's no point telling you what the other codes mean. Besides, I'd have to run off and look them up. This timing instruction can also be added to the *002 and *004 codes.

When forwarding to your voice mail, Fido gives you an additional short cut so that you don't have to remember the actual phone number to forward to. Instead of setting the forward to the actual phone number, forward to 3436 (that spells FIDO). For example, to forward all calls unconditionally to your Fido voice mail, you would enter:

*21*3436#

The Fido system recognizes 3634 and converts it to the correct phone number for you. If you use the status code *#21# right after you do this, you will find your phone forwarded to the correct voice mail phone number.

And here's another thing that can come in really handy if you wish to screen calls. Most of you probably guessed that if you set Forward if Not Answered, you can check the call display and ignore calls you don't wish to take. After the phone has rung 5 or 6 times, it will forward to the designated number (mostly likely your Voice Mail). Having the phone ring and ring like that is hardly a great solution if you're at a meeting, and changing the forwarding wait time to 5 seconds (the minimum allowed) means you may not have sufficient time to answer those calls you do wish to receive.

Here's how you can handle this situation using your GSM phone. Instead of setting the Forward if Not Answered feature to the desired phone number, set the Forward if Busy feature instead (or as well). Now when your phone rings, check the incoming number and if isn't someone you wish to speak with, press the END key. This tells the GSM to immediately forward your call. Nifty eh? And by the way, if you press END while a call is coming in, and you haven't set a phone number to forward to, then the caller starts getting a busy signal.

Call Waiting

Suppose you have just called a phone number where you end up on hold. While listening to the annoying music in the background you receive a second call via call waiting. You don't really want to answer that call, since it would put your first call on hold. Someone might answer while you were away, and besides, you don't want to run up the airtime if you can no longer service that call. All you need to do to terminate the first call before answering the second call is to press the END key. This will tell the GSM network to end your current call, but right away the phone will start to ring. To answer this call, just press the TALK button.

Did you know that you can take a call waiting party and allow them to join in your current conversation? When the second call comes in, answer it as usual by pressing the TALK button (or by selecting the answer option on the appropriate soft key). After confirming with the caller that he or she wishes to join your current conversation, choose the Join (or Conference) option on your phone. For a Nokia 2190, this entails pressing the Menu key and holding it for a half second. On the 6190, just press the Options soft key. You'll find the Join (Conference) option in the list that appears on your screen. I don't own either the Ericsson or Nortel phones, so I don't for sure how to get to the Join option on those phones.

You can quickly disable Call Waiting by entering #43# then pressing TALK. You can re-activate Call Waiting by entering *43# and then pressing TALK. You can check the Call Waiting status by entering *#43# and pressing TALK.

Text Messaging

When you first signed up for Text Messaging, your phone was automatically programmed with the Fido Message Center Number (or SMSC for short). This would be fine if it were possible to send text messages to any other GSM phone in the world through this number, but it isn't. Some GSM providers, such as PacBell in California, will not accept text messages sent to its subscribers from the Fido SMSC.

All is not lost however, since you can change the SMSC in your phone to that of PacBell's (or most other SMSCs in North America), and both Fido will allow this. By changing your SMSC to +12099042010, you can freely send text messages to any subscriber on the PacBell network. Don't forget to change it back to +15149931123 once you are finished.

Fido seems to disable the multiple "Message Sets" provided by the 6190. This would have allowed you to enter different SMSC numbers in each of the 5 groups and select the one you wanted. You can still change the SMSC easily enough on the 6190, but it's a shame you are denied an even easier way to do it.

I'm still experimenting with this to see what is and is not possible. Someone did post a message with a web site containing all the SMSCs for GSM providers around the world. Unfortunately I have been unable to find that address, but as soon as I do, I will post it here. Some SMSCs in other countries will send messages to your GSM phone. I recently tried a web page gateway in Austria and I received my message from that system within seconds. In the future, once the GSM providers stop screwing us around, we will be able to send and receive text messages from any GSM phone in the world WITHOUT changing the SMSC in our phones.

Showing Your Number

As you may already know, there is a menu item available on GSM phones that determines whether your phone number will be shown on the call display units of people you contact. However, did you know that you can override this setting on a per-call basis?

Say you normally display your phone number, but once in a while you want to hide it. To do that, put #31# in front of the number you are dialing. For example:

#31#4165551212

You could also store some of your phone book entries with #31# in front of them. This is handy if you have someone you call regularly who you don't want to send your number to. Let's face it, some people won't answer their phone if they know it is you calling.

Now suppose you normally didn't like your number displayed, but once in a while you did want to show it. To do that, put *31# in front of the number you are dialing. For example:

*31#4165551212

NOTE: Microcell Connexions also supports the use of the landline standard *67 for suppressing your number. If you can't remember the GSM codes, you can always remember that one.

Call Timer

On all other cellular and PCS technologies, the call timer runs whenever you press the TALK (or SEND) button. In other words, the timer is basically stupid, and doesn't really know when you are being charged and when you aren't. GSM on the other hand has full control over your timer. Calls are billed from the time the called party picks up his phone, and NOT from the time you press TALK. Next time you play with your phone, try calling your home number and let it ring 5 or 6 times before you answer. Note that the timer doesn't begin until you pick up the phone. Also check your next bill, and you'll find that the service provider only charged you for the time you were ACTUALLY CONNECTED.

Since the network has control of your timer, it can decided whether your timer should even run. Try calling a phone number that doesn't exist, so that you'll get the recording that says "We're sorry, but your call cannot be completed as dialed". You'll find that your timer doesn't run AT ALL under these circumstances, even though you are on the air.

This fine timer control was built in as part of a feature set that lets users see how much a phone call is costing him. Many North American GSM providers (including Fido) disable this call cost feature since they basically expect you to do most (if not all) your calling within the free minutes they provide each month. If your GSM provider charges you airtime for most calls, they might very well have activated the call cost feature.

Feedback received on this FAQ entry:
  • what about the use of the "*31#" option and text messaging? specifically with an android phone associated with gmail. the "*31#" option prevents text messaging, i have had limited success with adding a number without the "*31#" prefix and adding a "+1" prefix any thoughts?

    2012-04-06 18:47:49



by elusion See Profile

GSM (Global System for Mobile) is a digital cellular radio network used in over 200 countries worldwide. It is the dominant standard in Western Europe with nearly complete coverage and is growing in the Americas, Asia and other areas too.

GSM uses three frequency bands.

GSM 900 - operates in the 900 MHz frequency range and is the most common in Europe and most of the world.
GSM 1800 - operates in the 1800 MHz frequency range and is found in a growing number of countries already using GSM 900.
GSM 1900 (also called PCS (Personal Communication Services) 1900) - is used in the United States and Canada.

A significant feature of GSM is roaming; this allows cellular subscribers to use their services in any GSM service area in the world in which their provider has a roaming agreement.

by elusion See Profile

On a GSM cellular phone you can key in the following command **61*phone number#send to divert calls when your cellular phone is switched off, out of coverage or if you choose not to answer it. The "phone number" referred to is the access number (including the area code) for your pager operator service. For all other types of mobile phone you should consult the handbook supplied with the phone or the Phone Company providing you with cellular service.

by elusion See Profile
last modified: 2003-05-27 22:33:36