storing, by the service provider, power spectral density information of corresponding lines that is obtained in a process of receiving a service by each service receiving side device, generating a power spectral density template, and storing a service transmission rate and {TAIL ~ a topology scenario parameter} that are provided by each service receiving {HEAD ~ side device}; and 
storing , by the service provider , power spectral density information of corresponding lines that is obtained in a process of receiving a service by each service receiving side device , generating a power spectral density template , and storing a service transmission rate and { TAIL ~ a topology scenario parameter } that are provided by each service receiving { HEAD ~ side device } ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH