Sony Ericsson P802 manual CS-1 05kbps CS-2 13.4kbps, 36.2 53.6

For Internal Use Only	P800 Smartphone
	White Paper, May 2002

P800 supports up to 4+1 timeslots receive + transmit. The GSM network will dynamically allocate timeslot resources depending on current network conditions.

The capacity of each timeslot depends on the network and four coding schemes are defined, CS- 1 to CS-4. These are different to the capacities in HSCSD due to the differences between circuit- switched and packet data operation. GPRS networks are typically launched using CS-1 and CS-2 only, limiting maximum speeds to those shown in bold below. The P800 supports CS-3 and CS-4 and will operate at the higher speeds where introduced by mobile operators.

	CS-1	9.05kbps	CS-2 13.4kbps	CS-3 15.6kbps	CS-4 21.4kbps
Rx		36.2	53.6	62.4	85.6
Tx		9.05	13.4	15.6	21.4

The diagram below shows how the P800 in GPRS mode will send data in packets, combining timeslots when extra bandwidth is required, up to a maximum of 4 for received data and 1 for transmitted data

Applications such as Messaging and the integrated browser will automatically initiate CSD, HSCSD and GPRS connections, warning you if your desired action requires another connection to be cut. Whilst a CSD/HSCSD connection is terminated after the transaction or a period of inactivity, the GPRS connection will be maintained. This means that, for example, Web and WAP pages may be browsed without any connect delay, and that the E-Mail client can automatically poll for new messages.

When using the P800 as a modem to a PC, the GPRS connection is initiated from the PC as usual by selecting a Windows DUN connection, either explicitly within the DUN folder or implicitly via the usual way that Windows enables applications to request connections. Where a GPRS connection is defined in the DUN entry, the P800 will initiate a GPRS attach and connect to the GPRS network.

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