Methods and media access controller for broadband wireless communications with variable data unit size and delayed data unit construction

This application is a continuation of U.S. patent application Ser. No. 11/005,841, filed Dec. 7, 2004, which is incorporated herein by reference in its entirety.

This patent application is related to U.S. patent application Ser. No. 11/005,801, entitled “MEDIA ACCESS CONTROLLER WITH ENHANCED DATA UNIT RETRANSMISSION FOR BROADBAND WIRELESS COMMUNICATION AND METHOD” and filed Jun. 6, 2005.

Embodiments of the present invention pertain to broadband wireless communications. Some embodiments of the present invention relate to media access control.

In some wireless communication systems, such as broadband and WiMax-type communication systems, data may be transmitted to receiving stations in bursts. Due to the volatile nature of the communication channel, the burst size of the physical layer frames may have to be changed frequently to help ensure successful transmissions. As a result, a media access controller of a conventional transmitting station may have to reconstruct previously constructed data units to fit into either smaller or larger burst size frames. This reconstruction is very time sensitive and any delay may result in a lost transmission opportunity leading to in-efficient spectrum usage.

Some embodiments are directed to a media access controller that includes a per-flow scheduler, a data unit constructor, and a physical layer. The per-flow scheduler generates a data unit payload from one or more service data units of an associated service flow of two or more service flows. The data unit constructor constructs an initial data unit from the data unit payload after the data unit payload enters a retransmission request window. The physical layer initially sets a physical-layer burst size based on channel conditions and to change the physical-layer burst size in response to changing channel conditions. The per-flow scheduler reduces a size of the data unit payload when the physical layer changes the physical-layer burst size at a rate greater than a nominal rate, and increases the size of the data unit payload when the physical layer changes the physical-layer burst size at a rate less than the nominal rate.

The following description and the drawings illustrate specific embodiments of the invention sufficiently to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. Embodiments of the invention set forth in the claims encompass all available equivalents of those claims. Embodiments of the invention may be referred to, individually or collectively, herein by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed.