The number of allocated PDCHs in a cell can be increased or
decreased according to demand. In order to implement this
principle, a load supervision function, which monitors the
load of the PDCHs and the number of allocated PDCHs in a
cell can be increased or decreased, must be used in the
system. Upon resource demand for circuit switched services,
some PDCHs must be released as soon as soon as possible.
The release can have two alternatives:
1) immediate Release: the GPRS user is forced to stop its
transmission until resource is available for GPRS again
and the channel released by GPRS is allocated to circuit
switched services.
2) Delayed Release: the GPRS user can continue its
transmission up to some frames or until the ending of
packet transmission, before the channel is allocated to
circuit switched services.