Abstract: According to the present invention, one antenna (10b) receives a signal, and a handoff determination means (100a) monitors Ec/Io obtained by a searcher (16a) and determines whether a handoff condition is met or not. When the handoff condition is met, a switching control means (100b) switches the antenna used for reception to the other remaining antenna (18) to receive a signal. When a further handoff condition is met or only when a handoff condition is met in response to signals received by the two antennas (10 and 18), handoff control is performed.

Abstract: In idle handover control, the reception quality of a synchronized pilot channel is classified into quality class “1” with which data can be received without any error, quality class “2” with which data can be received within an allowable error range, or quality class “3” with which data is difficult to receive with high quality, and different thresholds, i.e., 6 dB, 4 dB, and 2 dB, are respectively set for these quality classes. It is checked whether the reception quality of another pilot channel as a synchronization establishment candidate is higher than that of the synchronized pilot channel by a threshold corresponding to a quality class into which the synchronized pilot channel is classified or more. If it is determined that the reception quality of the synchronization establishment candidate is higher by the threshold or more, handover processing is performed. Otherwise, synchronization with the synchronized pilot channel is maintained without handover processing.

Abstract: In a cable network system of this invention, GSUs are installed in almost all subscriber residences. A G-STB or a G-MDM is set for a subscriber who wants to receive bidirectional services. Alternatively, an NGA is attached to an existing N-STB or N-MDM. The presence of an upward transmission signal from an in-home device is monitored in the G-STB, the G-MDM, or the NGA. While the upward transmission signal is detected, a transmission indication signal is supplied to the GSU. Only while the transmission indication signal is detected, the GSU sets a gate switch in an ON state. On the other hand, while no transmission indication signal is detected, the GSU keeps the gate switch in an OFF state.

Abstract: Two switches and a bypass line are provided to enable formation of a bypass route for transmitting a transmission signal bypassing a power amplifier. A configuration may be employed in which a first threshold value and a second threshold value that is a little bit lower than the first threshold value are set and the power amplifier is separated when the reception power exceeds the first threshold value and is connected when the reception power becomes lower than the second threshold value. That is, the power amplifier is connected and disconnected with hysteresis. This configuration can prevent the phenomenon that the power amplifier is connected and disconnected repeatedly and frequently in the above mentioned situation.

Abstract: In a cable network system of this invention, GSUs are installed in almost all subscriber residences. A G-STB or a G-MDM is set for a subscriber who wants to receive bidirectional services. Alternatively, an NGA is attached to an existing N-STB or N-MDM. The presence of an upward transmission signal from an in-home device is monitored in the G-STB, the G-MDM, or the NGA. While the upward transmission signal is detected, a transmission indication signal is supplied to the GSU. Only while the transmission indication signal is detected, the GSU sets a gate switch in an ON state. On the other hand, while no transmission indication signal is detected, the GSU keeps the gate switch in an OFF state.

Abstract: First and second diodes are formed on the same semiconductor substrate. Both the diodes are forward biased by a direct current power supply. An attenuator is connected to a positive terminal of the first diode to produce an output lower in level than a voltage on the positive terminal of the first diode. A comparator receives the output of the attenuator as a first input and a voltage on a positive terminal of said second diode as a second input. When the first input is smaller than the second input, the comparator produces an output "0." When the first diode is open-circuited and the first input becomes greater than the second input, the comparator produces an output "1" and detects the fault of the first diode.

Abstract: Apparatus in which a gas such as air, containing nitrogen oxides, is mixed with high temperature steam of 130.degree. to 150.degree.C in a reactor vessel to convert the nitrogen oxides to soluble substances and then dissolve said soluble substances in a liquid absorbent such as warm water or a weak alkaline warm aqueous solution, said liquid absorbent being collected thereafter, so that the nitrogen oxides are separately removed from the gas. The apparatus of the invention has an attainable efficiency of separately removing nitrogen oxides exceeding 95 percent, for gas having the nitrogen oxides content of 100 ppm to 10,000 ppm.