Method for variable block scheduling indication by an uplink state flag in a packet data communication system

DETAILED DESCRIPTION The invention will now be described with respect to a GPRS system where a dynamic resource allocation method is provided for multiplexing mobile users by way of an USF transmission in the downlink.
Mobile users sharing a transmission resource listen to an USF transmission in the downlink in order to determine when uplink transmissions are permitted.
The uplink dynamic allocation method, according to conventional systems, is based on an USF granularity of one radio block, i.
e.
, a single USF appearance in a downlink radio block determines the uplink reservation for only one block.
This is illustrated in FIG.
4, where every downlink radio block includes an USF allocating the following uplink block to a mobile user.
The present invention recognizes that the USF granularity can be altered per single channel allocation from one to several consecutive blocks which means that a single appearance of the allocated USF is interpreted by a mobile station as an allocation of several sequential radio blocks for uplink transfer.
This technique slightly diminishes the flexibility of the dynamic allocation method, but provides advantages for other applications.
Because the reservation of a plurality of blocks on the uplink can start anywhere, it is advantageous to broadcast the proper USF only in the first block in the sequence, while in the rest of the radio blocks an unused value for USF is transmitted in order to prevent other users from transmitting in the uplink.
A mobile which earlier has received an allocation indication for a number of consecutive radio blocks will, upon receiving such an unused USF, ignore this for the period defined by the uplink allocation.
An unused USF value should be available on a packet data channel also for other purposes, e.
g.
, to have a way to keep MSs from transmitting on the uplink in certain cases, such as during certain control information transmissions.
By allocating, for example, four consecutive radio blocks on one uplink timeslot by one appearance of USF, it is possible to use the other 3 radio blocks more freely on the downlink