The rules for transmitters operating in the 260MHz- 470MHz band are governed by Part 15.231. In some bands the FCC specifies only the fundamental power, harmonic levels, and allowed bandwidth. However, in the case of the 260MHz-470MHz band, the FCC also considers factors such as the intended application and transmission duration. Given the rules’ complexity and application-dependent nature, they are best illustrated by the flowchart shown on this slide. The primary intent for this band is for remote control applications.There is a distinction between manual transmissions where a person presses a button and automatic transmissions where an event triggers a transmission without any input from a person. This operation is specified in paragraphs A-D in Part 15.231. The output power, harmonic power, and bandwidth of the radio signal are also specified in these paragraphs. Paragraph E outlines operation that is not remote control, such as real-time data transmissions which are subject to strict requirements on output power and transmission duration. Many applications try to sneak into this band since the radios typically used are less expensive, so it is critical to understand the rules and be sure that the intended application is allowed in this band. Typical applications in this band include car keyfobs, garage door openers, security systems and alarms, and short range sensor systems.