User guide

Developers guidelines | AT commands
344 June 2010
Short message service (SMS)
A text messaging service permitting the transmission of up to 160 characters to a
facsimile, X400, telex and voice services or mobile phone.
SIM card
Subscriber Identity Module card. It is a card that must be inserted in any GSM-based
mobile phone. It contains subscriber details, security information and memory for a
personal directory of numbers. The card can be a small plug-in type or credit card-
sized but both types have the same functions. Your phone uses the small plug-in card.
SIR
Serial Infrared
SM
1. Short Message
2. SIM message storage.
Synchronous Communication:
V.2 2b is
ITU-T standard for 2400 bps.
V.2 7t er
ITU-T standard for 4800 bps full-duplex modems connected to switched telephone
networks.
V.29
ITU-T standard for 9600 bps half-duplex modems included in FAX machines.
V.4 2b is
ITU-T standard for the compression of asynchronous data. V.42bis is based on a
dictionary that looks up common strings and replaces the strings with code words.
This reduces the amount of characters actually being transmitted. V.42bis has been
found to be most effective for file transfers that contain long strings of repetitive
information and least effective for short strings of unique data. It requires LAPM,
MNP2, MNP3 or MNP4 as error correcting.
TA
Terminal Adaptor, which in most cases is a PCMCIA (Personal Computer Memory
Card International Association) card.
TAE
Terminal Adaptor Equipment
TCP/IP
Transmission Control Protocol/Internet Protocol
TE
Terminal Equipment, which in most cases is a computer.
Unsolicited result code
A message sent from the modem to the PC that is not a response to an executed AT
command. For example RING.