A method for interference coordination, a network server, and a communication system are provided. The method includes the following steps. A first macrocell almost blank subframe (ABS) pattern is received from a first macrocell. A second macrocell ABS pattern is received from a second macrocell. A first small cell ABS pattern for a first small cell is determined according to the first macrocell ABS pattern and the second macrocell ABS pattern. The first small cell ABS pattern is transmitted to the first small cell. The first small cell is within a coverage of the first macrocell.