Wireless ATM metropolitan area network

A subscriber terminal (ST) for a wireless ATM metropolitan area network including:

• subscriber interfaces;
• a MAC framing and timing processor for transmission of ATM cells;
• forward error correction circuits;
• and
• a radio unit having an enclosure, mounting and alignment hardware, and an attached lens horn antenna,
• wherein the ST transmits one ATM-cell burst per ATM-type grant received from a base station, said grant information including a grant type, and said ATM-cell burst is received by the base station at a fixed time interval from the transmission of a corresponding grant from the base station to the ST.

A method for scheduling transmission of ATM cells for CBR services from subscriber terminals to a base station over a point-to-multipoint network over a shared medium wherein said base station can grant the time slot of said transmission to any CBR virtual circuit, the method including the steps of:

• (a) creating grants for multiple CBR virtual circuits at the base station, wherein each grant is first scheduled for a time slot that minimizes cell delay variation for a corresponding virtual circuit;
• and
• (b) if two or more grants are scheduled for a first time slot, re-scheduling at least one of said grants to a second time slot;
• wherein each ST transmits one ATM-cell burst per ATM-type grant received from the base station, said grant information including a grant type, and said ATM-cell burst is received by the base station at a fixed time interval from the transmission of a corresponding grant from the base station to the ST.