PHILIPS FISIO625 LEVEL2
Instrukcja Serwisowa

Départ. Technical support- CM640

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PHILIPS Consumer Communications Centre du Mans

Service Repair Support

VY-V-640-620-3 Page : 18 of 63 Language : EN Date : 11/02/03

With the GPRS, a transmission rate included between 40 and 115 kbit/s is available. Everything depends on the number of virtual canals or " time slots " used, and on coding scheme (CS1 to CS4). GPRS acts on the compression of the data as a multiplier of transmission rate. In 3+1 multislots mode (three slots for the network towards mobile, and a slot for the mobile towards network), it�s allows a transmission rate of 40 kbit/s with a CS2 coding scheme. With (8+1)multislots using the CS4 coding scheme, one achieves in practice 115 kbit/s (in theory 175 kbit/s). If, as it seems to be the current will of the operators, GPRS re-uses the existing GSM infrastructure, notably by keeping the network of current base stations ( BTS), upgrading the BTS software.

Average time to send an E-mail with a 10 pages attached document :

Standard Current GSM Standard Modems (V90) RNIS GPRS EDGE UMTS

Rate 9,6 kbit/s 57,6 kbit/s 128 kbit/s 144 bit/s * 384 kbit/s * 2 Mbit/s * : in optimal conditions

Time elapsed 7 min. 70 sec. 31 sec. 28 sec. 10 sec. 2 sec.

Three types of air terminals
Three types of air terminals were defined to meet the needs of the GPRS: the basic model (class B) is foreseen for the voice and the data in not simultaneous mode. The professional or industrial model (class C) is data exclusively (the air terminal is used as a modem). Finally the up-market (class A) is compatible voice/data simultaneously. This class A terminal is problematic. The power of calculation required at the moment has a strong incidence on its production cost and makes it dissuasive.

In the GPRS standard, three new types of mobile terminal have been defined: Class A terminal, which supports simultaneous circuit-switched and packed-switched traffic; Class B terminal, which supports either circuit-switched or packed-switched traffic (simultaneous network attachment) but does not support both kinds of traffic simultaneously; Class C terminal, which is attached either as a packed-switched or circuit-switched terminal. The terminal types are further differentiated by their ability to handle multislot operations. The terminal can use from 1 up to 8 time slots on the uplink and on the downlink channel. 18 services classes are defined in function on the number for support time slots.

� PHILIPS ELECTRONICS N.V. 1999 All rights reserved. Reproduction in whole or in part is prohibited without the written consent of the copyright owner.

VY-V-640-620-3