User Manual

XT55/56 Hardware Interface Description
Confidential / Preliminary
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XT55/56_hd_v02.96 Page 41 of 125 18.08.2005
3.4 Automatic GPRS Multislot Class Change
Temperature control is also effective for operation in GPRS Multislot Class 10. If the board
temperature increases to the limit specified for restricted operation
1)
while data are
transmitted over GPRS, the module automatically reverts from GPRS Multislot Class 10 (2
Tx) to Class 8 (1Tx). This reduces the power consumption and, consequently, causes the
board’s temperature to decrease. Once the temperature drops to a value of 5 degrees below
the limit of restricted operation, XT55/56 returns to the higher Multislot Class. If the
temperature stays at the critical level or even continues to rise, XT55/56 will not switch back
to the higher class.
After a transition from Multislot Class 10 to Multislot 8 a possible switchback to Multislot
Class 10 is blocked for one minute.
Please note that there is not one single cause of switching over to a lower GPRS Multislot
Class. Rather it is the result of an interaction of several factors, such as the board
temperature that depends largely on the ambient temperature, the operating mode and the
transmit power. Furthermore, take into account that there is a delay until the network
proceeds to a lower or, accordingly, higher Multislot Class. The delay time is network
dependent. In extreme cases, if it takes too much time for the network and the temperature
cannot drop due to this delay, the module may even switch off as described in Chapter
3.3.3.1.
1)
See Table 26 for temperature limits known as restricted operation.