Q. Elucidate the working of broad band ISDN?

Ans:

BISDN Configuration: Figuredemonstrates how access to BISDN network is accomplished. Every peripheral device is interfaced to the access node of a BISDN network through a broadband distant terminal (BDT). BDT is responsible forelectrical to optical conversion, multiplexing of peripherals and maintenance of subscriber's local system. Excess nodes concentrate numerous BDT's into high speed optical fiber line directed through a feeder point into a service node. Most of the control function for system excess is managed by service node, like administrative function, call processing and switching as well as maintenance functions. Functional modules are interconnected in a star configuration and include administrative, switching, maintenance andgateway modules. Interconnection of the function module is displayed in Figure. Central control hub acts as end user interface for control signalling and data traffic maintenance. Essentially, it oversees the operation of modules.

Subscriber terminal near control office may bypass the excess nodes completely and directly connected to the BISDN network via a service node. BISDN nodes that used optical fiber cables can utilize much wider band width and therefore, have higher transmission rates and offer more channel handling capacity than ISDN systems.