ratecontrol

Rate control is the process of regulating the rate at which data is transmitted or encoded to meet constraints such as bandwidth, latency, and quality of service. It encompasses techniques used across networking, multimedia, and control systems to avoid congestion, underflow, or waste.

In networking and wireless communications, rate control includes congestion control algorithms that adjust the sending rate in response to network feedback. In wireless 802.11 networks, rate adaptation selects a modulation and coding scheme to maximize throughput given channel conditions. Classic algorithms include ARF, AARF, Minstrel, and RAC.

Traffic shaping and policing use rate control to enforce an upper limit on sustained bandwidth. Mechanisms such as token bucket and leaky bucket regulate burstiness and enforce service policies.

In video and audio encoding, rate control determines the target bitrate based on bandwidth estimates and buffer status. Techniques range from constant bitrate to variable bitrate, with rate-distortion optimization guiding bit allocation.

In streaming, adaptive bitrate protocols (DASH, HLS) adjust the segment encoding rate in response to observed throughput and buffer occupancy.

In control theory and related domains, rate control refers to feedback loops that regulate input signals to achieve a desired output rate.

Goals and metrics commonly include efficient utilization of resources, fairness among users, stability of the transmission system, and quality of experience. Key metrics include throughput, latency, jitter, packet loss, and buffer occupancy.

Implementation considerations cover hardware and software constraints, latency sensitivity, and interoperability with other network traffic. Rate control remains essential for maintaining performance across diverse systems and applications.