PRINCIPLES OF THERESOURCE ALLOCATION FORGPRS
GPRS is designed to support from intermittent and burst data
transfers to occasional transmission of large volume of data.
The GPRS and GSM circuit switched services share the same
radio resource. Whenever a channel is not used by circuit
switched services, it may be utilized by GPRS. The allocation
of physical channels for GPRS can be based on the needs for
actual packed transfers which is referred to as “capacity on
demand” principle. When the packet data channels (PDCHs)
shared by all GPRS users are congested due to the GPRS
traffic load and more resource available in the cell, the
network can allocate more physical channels as PDCHs.
The GPRS does not require permanently allocated PDCHs.
The operator can decide to dedicate permanently or
temporarily some physical channels for GPRS traffic.
However, the high speed circuit switched data (HSCSD)
service supports as well multiple slot services and has higher
priority to access the physical channels. As the introduction of
HSCSD service into the GSM system, it might be difficult to
guarantee the quality of service of GPRS if no channel is
dedicated to GPRS.