| 摘要 |
<P>PROBLEM TO BE SOLVED: To ensure that, even when an encryption scheme which results in increased frame length is employed, station side and subscriber side devices are accurately synchronized in time. <P>SOLUTION: The present invention relates to as PON system station side device 1. The station side device 1 comprises: a write unit 110 which writes a timestamp into a prescribed downlink frame; an encryption unit 106 which applies encryption which results in increased frame length to a downlink frame requiring encryption; and a delay control unit 105 which executes a process to eliminate a fluctuation in the transmission delay of a first frame in (a) below attributable to encryption applied to a second frame in (b) below, or to restrict the fluctuation to within a prescribed range. (a) First frame: downlink frame into which a time stamp is written; (b) Second frame: downlink frame immediately preceding the first frame. <P>COPYRIGHT: (C)2013,JPO&INPIT |
