Random early detection over wireless links

Abstract

Random early detection (RED) controlled loss (i.e., discarding data packets) is determined as a function of change in processing gain assigned by a resource management system in a data network having a communications link between first and second network nodes. Rather than triggering RED controlled loss as a function of buffer levels, triggering is determined as a function of change in processing gain caused by, for example, a change in code rate, modulation technique, error (e.g., bit error rate or frame error rate), signal-to-noise ratio (SNR) or carrier-to-interference (C / I) level, or a number of traffic code channels or TDMA slots assigned to the nodes. In a wireless data network, this technique may be deployed in a base station or access terminal. A tight coupling between the physical layer and link layer is provided using this technique.

Description

CROSS REFERENCE TO RELATED APPLICATION(S)[0001]This application is a continuation of U.S. patent application Ser. No. 10 / 302,797, filed Nov. 21, 2002, which is incorporated by reference as if fully set forth.BACKGROUND OF THE INVENTION[0002]Random Early Detection (RED) is a buffering technique that allows a controlled level of loss to occur in packet buffers within routers when congestion is perceived. This controlled loss allows flow control processes within the transport control protocol (TCP) to scale back sending of data on a particular link or flow.[0003]Controlled loss may also be performed on real time and near real time streams according to loss profiles that limit degradation to a level acceptable to end users. The controlled loss in an RED implementation is performed on a weighted basis, with flows occupying larger portions of the aggregate traffic flow having a higher probability of loss in the case of congestion.[0004]In RED controlled loss techniques, the deciding facto...

AI Technical Summary

Problems solved by technology

Using the breaching of buffer levels to trigger Random Early Detection (RED) controlled loss can result in the communications link going into either ‘congestion avoidance’ or ‘slow start’ modes simultaneously.

For wireless systems, these two phases of TCP are extremely inefficient because data is sent in small amounts instead of attempting to fully utilize the capacity of the assigned RF data link.

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