The method and speed of transmission is an important and often overlooked factor in determining both the range and responsiveness of a link. Two of the most common methods of sending data are Pulse Width Modulation and serial bit stream. With Pulse Width Modulation the receiver will start a timer on the rising edge of the pulse and stop it on the falling edge, and interpret this time as either a 1 or a 0. With serial bit stream the receiver will look for a rising edge of the first bit, wait ½ bit time to get to the center of the bit, then wait 1 bit time to sample each bit in its center. In general, serial bit streams are more noise tolerant and result in better system range.