Patent ID: 7739502

Claim:
In a network of source and sink devices interconnected to a 1394 bus, a localization method comprising: a source device generating message content; the source device encrypting the message content; the source device sending the message with encrypted content to the sink device over the 1394 bus, and concurrently starting a timer; the sink device receiving the message and decrypting the content; the sink device generating reply content based on the decrypted content; the sink device encrypting the reply content; the sink device sending the reply message with encrypted reply content to the source device over the 1394 bus; the source device receiving the reply message and decrypting the content; the source device checking the decrypted reply content such that if the decrypted reply content meets certain criteria, the source device stops the timer, wherein the time measured by the timer indicates round trip time between the source device and sink device on the 1394 bus.