A British company has developed a 'wireless' transceiver for short-range computer serial data communications
                    operating on 433.92 MHz for use where cabling is difficult or impossible.

                    Developed by Low Power Radio Solutions (LPRS), the equipment is made in different versions, using different
                    frequencies, to suit the domestic UK and European markets.

                    Models destined for the European market operate on either 418 MHz or 433.92 MHz, which are European
                    industrial-scientific-medical (ISM) bands not requiring equipment licensing, while the UK product operates on 458
                    MHz, a UK ISM band.

                    The European units have an output power of 0.25 mW, while the UK units have a much higher output of 10 mW.
                    RS232 data at the standard 9-pin D-type transceiver input socket is transmitted in packets with a header and
                    checksum. The receiver verifies the checksum and removes the header. Narrowband modulation is used and the
                    maximum data rate is 1200 baud, said LPRS, but this means they are less prone to noise than higher speed,
                    wideband units.

                    The line-of-sight range of the transceivers is about 120 metres, which falls to 30-50 m inside buildings, according
                    to LPRS. Suggested applications include data communications from sensors, such as temperature and pressure,
                    or data from swipe card readers.

                    The Australian Communications Authority has recently Class-licensed the 433.05-434.79 MHz band in Australia for
                    such applications, upgrading the original 1993 Class licence. The LPRS wireless data link units are not presently
                    available in Australia, but represents the sort of equipment for which the "low interference potential devices" (LIPD)
                    Class licence was created.