* ``packet`` - the [packet](/reference/radio/packet) that was received by the radio. The packet has the following properties:
*`receivedNumber` - The [number](/reference/types/number) that was sent in this packet or `0` if this packet did not contain a number. See [send number](/reference/radio/send-number) and [send value](/reference/radio/send-value)
*`receivedString` - The [string](/reference/types/string) that was sent in this packet or the empty string if this packet did not contain a string. See [send string](/reference/radio/send-string) and [send value](/reference/radio/send-value)
*`time` - The system time of the micro:bit that sent this packet at the time the packet was sent.
*`serial` - The serial number of the micro:bit that sent this packet or `0` if the micro:bit did not include its serial number.
*`signal` - How strong the radio signal is from `255` (weak) to `0` (strong).