IMPROVED CONGESTION CONTROL USING ACCESS CLASSES

摘要

In order to control traffic congestion in a cellular satellite telecommunications network, user terminals are grouped together in different predetermined access classes which can be controlled individually in order to restrict access to the network. Cell broadcast messages are transmitted from SAN 1 via satellite (3a) to user terminal UT1 in a particular cell to provide coarse access class data corresponding to sub-groups of a plurality of the individual access classes permitted or denied access to the network. This coarse data is supplied in response to a predicted call traffic demand produced by a traffic planning model, exceeding the capacity of the network. Additionally, if the demand exceeds the levels predicted by the traffic planning model due to an unpredicted demand, fine access class information is transmitted to control the individual access in the sub-groups. The fine access class information, when it is transmitted is detected at a higher rate than the coarse access class information.