A method for dividing, into a plurality of sub-periods all having the same size, a Contention Access Period (CAP) of a superframe in regard to a Medium (or Media) Access Control (MAC) layer using a beacon-enabled mode in IEEE 802.15.4 standard, and then distributing contention among terminals by using the sub-periods, the method comprising the steps of:
- g) checking the number of terminals per sub-period, thereby determining if an imbalance among sub-periods related to the number of terminals exists;
- and
- h) giving a relevant terminal notice of the existence of the imbalance among sub-periods related to the number of terminals through a beacon frame if it is determined in step (g) that an imbalance among sub-periods related to the number of terminals exists.