Back-Channel Protection

Carrier Protection Channel

Channel Protection

channel protection against seepage

Channel-Channel Alignment

electric power optical-fiber relay protection channel

multiplex protection channel

Non-channel protection

Optical Channel Protection

Optical Fiber Protection Channel

optical fiber relay protection channel

optical-fiber protection channel

optical-fiber relay protection channel

Protection Channel

Relay Protection Channel

Virtual Channel Link

Virtual Channel Link Termination

virtual channel link， VCL

Yang Link Channel