In battery-powered applications, power consumption is a critical issue since it is desired to have the longest battery life possible. Surprisingly, the relationship between frequency and power consumption is often overlooked. Since propagation efficiency is reduced as frequency climbs, higher frequencies require more power to achieve a specific range. There are many ways of reducing power consumption. One of the most common methods is to cycle power to the radio at a low duty cycle. A duty cycle is a ratio of on time to off time. The lower the duty cycle, the more the radio is off. A 100% duty cycle means that the radio is always on. Usually the transmitter is turned off until it actually has something to send. This is typical of remote control systems like car keyfobs. The transmitter is off until a button is pressed to activate the system. The receiver frequently needs to be on all the time, but it can be cycled at the expense of response time. For example, the receiver can be activated for the length of time it takes to receive two packets and turned off for nine times that time and results in a 10% duty cycle. This increases the response time of the system by the length of the off time, but results in a 90% decrease in average current consumption. This method does not work for all applications but can be a huge benefit in many.