Method and apparatus for detecting attenuation of downlink channel in baseband epcn system

A Coax Line Terminal (CLT), comprising:

• an instruction sending unit, adapted to instruct a Coax Network Unit (CNU) in a downlink time period to measure a signal received by the CNU;
• and
• an attenuation obtaining unit, adapted to obtain attenuation of a downlink channel of the CNU according to a measuring result sent by the CNU.

A Coax Network Unit (CNU), comprising:

• a Media Access Control (MAC) layer chip, adapted to instruct a PHY chip to measure a signal received by the CNU when receiving an instruction sent by a Coax Line Terminal (CLT) in a downlink time period, and send a measuring result obtained by the PHY chip to the CLT;
• and
• the PHY chip, adapted to measure the signal received from the CLT according to the instruction received by the MAC layer chip and obtain the measuring result.