Loading patent…
AssigneesNippon Telegraph & Telephone Public Corporation, NEC Corporation, Kabushiki Kaisha Toshiba
InventorsRyoji Kawasaki, Kazuhiro Yoshizawa, Akio Yotsutani, Noboru Saegusa, Koichi Ito, Syozi Huse
Estimating the term…
A portable unit that may be called from a base station through a radio control channel by a succession of terminating call signals that is sent through the control channel from the base station to the portable unit for a first or restricted time duration (T.sub.1), selected in consideration of a battery saving period of a battery saving operation carried out in the portable unit. Within the battery saving period, the portable unit is put into transient active and inactive states during a first time interval and a second time interval, respectively. Selection is made so that the first time duration is longer than the second time interval to receive at least one of the terminating call signals within the first time duration in the portable unit. The base station monitors an acknowledgement signal for a second time duration (T.sub.2) after the lapse of the first time duration and interrupts the control channel when the acknowledgement signal is not received within the first and the second time durations. In the portable unit, the battery saving operation is released when the presence of the terminating call signals is detected by a squelch circuit.
A method of calling a portable unit from a base station through a radio control channel, said method comprising the steps of repeatedly producing in said base station a terminating call signal as a call signal sequence, periodically putting said portable unit into transient active and inactive states during a first time interval and during a second time interval following said first time interval, respectively, and keeping said portable unit into a continuous active state when one of said terminating call signals is received during said first time interval, wherein the improvement comprises the steps of:
A base station responsive to an incoming call for calling a portable unit by the use of a sequence of terminating call signals, each being related to said incoming call, said portable unit being periodically put into transient active and inactive states during a first time interval and a second time interval following said first time interval, respectively, wherein the improvement comprises:
Dependencies are inferred from the claim text.