OPTICAL ROUTER FOR REMOVAL/ADD CHANNEL AND OPTICAL FIBER CROSS CONNECT

摘要

PROBLEM TO BE SOLVED: To provide protection for network security for a wireless subscriber channel system in order to avoid illegal use of the network by an unapproved user. SOLUTION: Assuming that a propagation delay between a base station 1 and a subscriber terminal 3 is kept constant and the propagation delay can sufficiently accurately be measured, the distance from the subscriber terminal 3 to the base station 1 can be determined. This means that this distance can be used for auxiliary information to authentication of a subscriber. Other signal characteristics denoting an actual position of an opposite party pretending the subscriber such as range finding information may also be used. In a system for other object such as orthogonal CDMA code synchronization or a TDM system needing to supervise the propagation delay in any case can obtain furthermore security protection without an expensive additional charge.