Specifications

Standards ETSI 07.05 and 07.07 and 07.10, V.25ter command set supported

Data rates, Circuit Switched

download (up to) 28,800 bps for High Speed Data communication

upload (up to) 9,600 or 14,400 bps for GSM Data communication, no compression

with V.42bis compression up to four times higher transmission rates

Data rates, GPRS See ÒTechnical speciÞcations of GPRS in R520Ó on page 25.

This section outlines the AT commands supported by the R520. The information here can be of

use for advanced users, to indicate the possibilities they have to:

¥ develop new communications software

¥ add the R520 to an applicationÕs list of compatible modems

¥ adjust the settings of their mobile telephone and modem

The modem in the R520 supports the V.25ter command set, which is the standard communica-

tion set used by modems.

The R520 is compatible with industry de facto extensions, ETSI 07.05, 07.07 and 07.10.

You use AT commands to conÞgure your mobile telephone, to request information about the

current conÞguration or operational status of your mobile phone, and to test availability and

request the range of valid parameters, when applicable, for an AT command.

The built-in modem can be set in any one of three modes of operation. These are:

Off-line Command

Mode The built-in modem is placed in off-line command mode when Þrst

powered up and is ready for entry of AT commands.

On-line Data Mode Allows ÒnormalÓ operation of the built-in modem, exchanging data or

facsimile with the remote modem.

On-line Command

Mode You can switch to on-line command mode when you want to send AT

commands to the built-in modem while still remaining connected to

the remote modem.

The AT commands in the R520 are grouped as follows:

¥ Control and IdentiÞcation

¥ Call Control

¥ Interface Commands

¥ Data Compression

¥ Mode Management

¥ Fax Class 1

¥ Fax Class 2

¥ Audio Control

¥ Accessory Menus