Power consumption control method of a communication system and related communication system

A communication system capable of controlling power consumption, comprising:

• a first network device, comprising:
• a first receiver;
• a first transmitter;
• a first checking module, for checking a receiving capability of the first receiver of the first network device to generate a first checking result;
• and
• a first signal transmitting module, for selectively generating a notice signal according to the first checking result;
• a first idle sequence voltage level adjusting module for lowering a voltage level of an idle sequence during idle mode to a predetermined voltage level such that a voltage range of the idle sequence is less than a voltage range for transmitting data under a normal mode;
• and
• a second network device, comprising:
• a second receiver;
• a second transmitter;
• and
• a second transmitting capability adjusting module, for adjusting a transmitting capability of the second transmitter of the second network device according to the notice signal,
• wherein the first signal transmitting module is further configured for transmitting a first notice signal to notify the second network device when the first checking result indicates that the receiving capability of the first receiver of the first network device is greater than a first threshold, and
• wherein the second transmitting capability adjusting module is further configured for lowering the transmitting capability of the second transmitter of the second network device when the first notice signal is received.