Link-Layer Buffering Requirements and Optimization of Gb/s Infrared Enabled Devices

We present an analytical model for dimensioning the buffering requirements of the link-layer in half-duplex Gb/s infrared links. Our model takes into account both physical layer parameters, including the bit-error-rate and the turnaround time of the link, and link-layer parameters, including the protocol window and frame size, in order to calculate the utilization efficiency of the infrared link as a function of the buffer size. We utilize the model to establish the buffer size that is required to achieve acceptable efficiencies for a broad range of standardized infrared link and link-layer protocol configurations. Our analysis shows that it is possible to optimize the link-layer window and frame size in order to achieve maximum efficiency for any given buffer size and link configuration, and we provide analytical relations for the buffer-constrained optimal window and frame size.