Patent ID: 7920559

Claim:
A transponder for relaying a signal, comprising: a determination unit which discriminates kinds of a plurality of reception signals and outputs a control signal for selecting a clock signal according to a transmission mode of a reception signal based on a discrimination result of said reception signal; and, a selection unit which switches a transmission mode by selecting automatically a clock signal according to said reception signal discriminated by said determination unit from among a plurality of clock signals set for each said reception signal which is used in transmission of said reception signal based on said control signal from said determination unit, wherein a plurality of said reception signals are STM-64/OC-192 signals or 10 Gbit Ethernet signals, and said determination unit discriminates whether said reception signal is said STM-64/OC-192 signal or said 10 Gbit Ethernet signal by detecting an A1A2 byte or a 64B/66B code synchronization bit.