Periodic attachment in future mobile telecommunications

In mobile telecommunications the network needs to monitor the terminal status, i.e., switched on, switched off, busy, idle. Once a mobile terminal is switched on, it automatically informs the network accordingly (attachment action). Regarding the way that the network identifies that a terminal is switched off (detachment), a procedure called periodic attachment is proposed: the terminal (when switched on) periodically reports to the network its active status. If the network detects silence for more than an agreed time period it considers the terminal switched off. Paging signalling savings can be achieved if the network is informed early that a mobile terminal is switched off. However, periodic attachment requires access to the network database system, which might cause a bottleneck. In this paper the performance characteristics of periodic attachment and the induced signalling load are evaluated as influenced by the selection of the time-out period. A constant time-out period for the whole day can cause a large amount of database transactions especially during low traffic hours. A method for dynamic time-out period selection to fit the varying conditions during the day is proposed and evaluated