Abstract: A wireless communication apparatus includes a memory, and a processor coupled to the memory and configured to calculate a variation amount based on a frequency difference between a first clock signal in a first synchronous processing apparatus and a second clock signal in the wireless communication apparatus according to a first message exchanged between the first synchronous processing apparatus and the wireless communication apparatus, calculate a correction amount based on a phase difference between a first time in a second synchronous processing apparatus and a second time in the wireless communication apparatus according to a second message exchanged between the second synchronous processing apparatus and the wireless communication apparatus, and when a failure is detected in the first synchronous processing apparatus based on the variation amount and the correction amount, switch an object for synchronization from the first synchronous processing apparatus to the second synchronous processing apparatus.

Abstract: A two-wire termination impedance generation circuit of a subscriber circuit including differential amplifiers, which is provided with a network circuit including capacitors and resistors, an input point, and current sources, the capacitor being comprised of series connected first and second capacitors, the resistor being comprised of series connected first and second resistors and having a high band bypass capacitor connected at the intermediate connecting point of the same, and the resistor being comprised of a complex termination resistor forming an internal termination impedance and a series connected complex termination resistor and complex termination capacitor being connected directly to the telephone line as an external termination impedance, wherein the frequency characteristics can be improved in three ways.