| 摘要 |
The invention relates to a method for establishing a communication channel, preferably an embedded control channel, between a central network node (3) and at least one network unit (7) to be integrated in a communication network (1) comprising the central network node (3) and an arbitrary but limited number of network units (7), the central network node (3) being adapted to create and output a WDM downstream signal (SD WDM ) comprising downstream channel signals to be transmitted to the network units (7) and to receive a WDM upstream signal (SU WDM ) comprising upstream channel signals (SU i ) created by the network units (7). The method is characterized by the steps of:
€¢ in a setup mode, creating a setup channel signal at the at least one network unit (7), the frequency spectrum of which comprises, as a modulation component, a setup label which is selected from a predetermined set of at least two setup labels, a predetermined setup address label being associated with each setup label, and transmitting the setup channel signal in the direction of the central network node (3);
€¢ detecting the presence of a new upstream channel signal created by the at least one network unit (7) within the WDM upstream signal (SU WDM ) by detecting a respective new setup label and determining the setup address label associated with the setup label detected, and creating a downstream channel signal (SD i ) receivable by the at least one network unit (7) by modulating the WDM downstream signal (SD WDM ) according to a downstream modulation signal (S mod ) comprising, as information to be transmitted to the at least one network unit (7), a setup information and an address information comprising the setup address label associated with the setup label detected; and
€¢ at the at least one network unit (7), receiving the respective downstream channel signal (SD i ) and extracting and further processing the setup information in case the setup address label included within the respective downstream channel signal (SD i ) equals the setup address label associated with the setup label of the setup channel signal that has been sent by the at least one network unit (7). |
