... equipment with ATPC functions, operation optimization;3. Rich user service interface, 4/8/16/24/32E1, LAN, E1+LAN ... of protection, 1+0 or 1+1backup and frequency diversity backup, stronger stability and reliability;9. Support analog service telephone call or ... frequencymeta-stable(ppm)±10Standby mode(1+0) No protection(1+1) Same frequency hot backup (1+1) Frequency diversity backupThe selection of ...