GSM device incompatibilities

Known bugs and incompatibilities of GSM devices

FALCOM A1 does not reply OK after AT+CPIN? command as any other devices do.

FALCOM A2 does not reply OK after AT+S0? command.

I've tested two different Siemens M1-s Ver.04.003 01.04.97, and I found some differences between them. (See command table.) This means, that the version number has no significance. :-(

Siemens M1 (Ver.04.003 01.04.97) accepts +CNMI mode 0 and 2 settings but always works as in mode 1.

FALCOM A2 (firmware 01.7f.02) is reported to have a bug. It does not accept the following command: ATS4=13 . As far as I know FALCOM A1 has the same problem.

Bosch 909 (and probably Bosch 908 also) requires SCA when sending a message but SCA is not displayed while listing stored messages.

Bosch 909 (and probably Bosch 908 also) replies commands AT+CGMI, AT+CGMM, AT+CGMR, AT+CGSN with incorrect syntax.

When executing AT+CMGL command FALCOM A2 sends an extra ASCII NUL character after each displayed PDU.

Siemens M20 sends an unsolicited OK after power-on.

TelItal GM360 is a real mess. At least ME versions v. 5.12 03/09/99 DATA-BLOCK and v. 5.13 b 11/01/01 DATA-BLOCK.

When a SM received GM360 sends unsolicited report

	+CMTI: "SM",26

or so, where the memory index has no relation to the place where message is actually stored. The number must be in range 1-10 inclusive. However the indicated index is an increasing number up to the infinity. This "feature" prevents any attempts to receive messages without polling.

If two messages arrive at the same time GM360 sends only one +CMTI report.

If you deletes a message from the memory all other messages at higher memory index shift down a position.

AT+CMGS and AT+CMGW command requires not the length of TPDU but length of SCA+TPDU. Similarly the AT+CMGL includes the SCA in the PDU length. However section 4.3 of GSM 07.05 writes that <length> must indicate the number of octets coded in the TP layer data unit to be given (i.e. SMSC address octets are excluded).

If you issue an AT+CMGS or AT+CMGW command GM360 raises DCD when it receives the <CR>. At the moment the <ESC> or <ctrl-Z> is arrived the DCD is dropped. This behavior cannot be influenced with AT&Cn command. Section 4.3 of document GSM 07.05 just requires that the DCD signal shall be ON state while PDU is given. Forcing it to OFF state after entering the PDU is not required.

After sending a stored message with AT+CMSS its state remains "unsent".

I found that all the six messages stored in SIM memory have index "1" when I listed messages with AT+CMGL=4. None of them can be deleted.

Motorola T260 (and probably P260 also) indicates stored (un)sent messages as received unread.

Anonym user reported a Nokia problem:

Subject: Nokia modem HEX bug
We talked about bugs in the modem modules, her is own from my Nokia 7110 (but it seems to be a general one, the 6090 Test Unit I have here, has it, too). That is Nokia Hex:
Only while writing, reading works fine.
Terminal -> Mobile UI
"x A"    -> "x+1 1"
"x a"    -> "x+2 A"
"A x"    -> "1 x"
"a x"    -> "A x"
Nice isn't it, that makes the HEX alphabet (which should be the best and easiest) near to USELESS. "*:JZjz" and many other do not work correctly. Now I have to check, if it is a Nokia and then map all "xA" characters to "x-2 a" ones. And "Ax" gets "ax" within my tool.
Subject: Re: Nokia modem HEX bug
You could even add a FIX for that bug: All Hex Values which contain an A must to be remapped or changed: "xA" has to get "(x-2)a" and it works than in the mobile: "xA" "Ax" has to get "ax". I would not recommend to use all lowercase, we do not what to know what else is broken in lowercase area! For example: "AA" -> "8a".
That works now. Luckily no one else uses HEX, so I do not have to check that.. But I am really curious if it is only 7110/6090. I have to test a 62xx and a 8xxx. Do not include the "6090". Officially I do not have it.
Subject: Re: Nokia modem HEX bug
Just checked: 8210 has it, too.
It seems really a overall bug in that "standard" modem software module.
I have to check an 6210.....
Subject: Re: Nokia modem HEX bug
6210 (FW 4.27) has it, too. It is a "standard" bug in all Hex Nokias.

A Motorola 260 problem is reported by Alex Traud:
This device denies +CPBR command until you select a preferred memory by +CPBS=memory.

Nokia Premicell gets crazy if &D2 settings enabled ("reset if DTR goes off"). Vital S registers get filled with garbage. Set &D0 manually then save this configuration.

Some versions of Wavecom WMOD2 have a hardware bug. RS-232 signals DCD and DSR are swapped. It is probably due to a bug in internal PCB design. So a firmware working well within previous models now crashes your application that listens to DCD. No upgraded firmware available as of April 2004.

The hardware solution: fabricate a DCD/DSR line swapper adapter yourself. Here is the "documentation":