Technical data

96 Theoretical and general applications www.westermo.com
GPRS classes
GPRS equipment is available in three categories, these are defined
as Class A, B and C.
Class A Supports simultaneous GSM and GPRS operations
Class B Supports GSM and GPRS operations, but not simultaneously.
Class C The connection only supports GPRS or GSM data. When switching is necessary
between GPRS and GSM you must reconnect the connection.
Maximum slots
GPRS Multislot class RX “downlink” TX “uplink” Max
Class 1 1 1 2
Class 2 2 1 3
Class 4 3 1 4
Class 6 3 2 4
Class 8 4 1 5
Class 10 4 2 5
Class 11 4 3 5
Class 12 4 4 5
Multislot classes with 1 to 4 time slots.
RX: Maximum number of received time slots that MS can support per GSM TDMA-frame.
TX: Maximum number of time slots that MS can send per GSM TDMA-frame.
Max: Total number of time slots on the uplink and downlink that can be used simultaneously by
the MS in the TDMA-frame.
UMTS (3G)
3G is the everyday name of a standard known as UMTS (Universal Mobile Tele-
communications System) in many countries, that describes the technology behind the
third generation telephone system. In some countries 3G may imply other correspon-
ding standards. The expression 3G comes from the fact that it is the third generation
of mobile telephony, the first generation was analogue, followed by GSM , which is the
most common system at present and now 3G has been launched.
The main difference between 3G and GSM is the transfer capacity, that is to say,
how fast data can be sent and received by the telephone. The higher the transfer rate,
the more the mobile network can be used for. The speed is about 40 times faster
using 3G, which means you can use advanced services such as: Send and receive
images, transfer moving pictures and utilise services based on the user’s position.
This is why 3G is known to many as mobile broadband.
B A C K