Ericsson T39 Modem and AT Commands, GSM Data Communication, High Speed Data Gives a Faster Speed

MODEM AND AT COMMANDS

The T39 contains a complete GSM modem. This provides data and e-mail communication, as well as internet/Intranet access, for a connected PC, PDA or handheld device. Once the PC/ PDA is connected to the phone using Bluetooth wireless technology, infrared or a cable, and the appropriate software is installed, the modem in the phone works in a similar way to a PC Card modem, or an external modem.

In the T39, AT commands are used both for:

•controlling the data communication between the PC and the remote service

•configuring and requesting settings and behaviours in the phone, from a connected PC or

PDA

GSM Data Communication

The built-in data capability turns the phone into a modem when connected to a PC/PDA. The T39 offers the user data connection anytime, anywhere, unmatched by fixed telephone net- works. Each GSM channel is divided into eight repeating time slots.

A normal GSM call only uses one of eight repeating time slots in the GSM channel, giving a data speed of 9,600 bps. The T39 supports a more efficient coding scheme, giving data speeds of up to 14,400 bps (providing the network supports this).

9,600/14,400

9,600/14,400

9,600/14,400

9,600/13,200

9,600/13,200

9,600/13,200

9,600/13,200

1

GSM 9,600 bps

14,400, 19,200 or 28,800 bps (HSCSD)

2

GPRS

9,600, 13,200, 19,200, 26,400, 28,800 or 39,600 bps

High Speed Data Gives A Faster Speed

High Speed Circuit Switched Data (HSCSD) gives the possibility to use two time slots for receiving data. In combination with a more efficient coding scheme, this can increase the receiving data speed up to 28,800 bps (network-dependent). Additionally, by using Data Com- pression (V 42bis) the experienced data rate can be increased up to four times.

GPRS Enables Constant Connection And High Speed

With GPRS, the connection is maintained “constantly”, and data is transmitted in packets. Pric- ing of GPRS can be dependent on the actual use of bandwidth, which means very low cost when no data is sent or received, while the phone remains connected. When transmitting large amounts of data, bandwidth can be increased automatically to allow faster transmission speed, up to 39,600 bps download speed.

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