Packet controllers come in several types. Some have on boar controllers and you simply interface to then via UART with framing you establish inside your 8051. Others have full protocol inside and handle full packet generation and reception. And finally there are the simplest types that are just a transmitter and the 8051 has to format the modulation signal (usually manchester encoding is required) and decode it. This latter type was discussed in this thread posted a day or so ago.... Re: whats the best chip to use

Michael Karas