DEMAND ASSIGN WAVELENGTH-DIVISION MULTIPLE-ACCESS (DA-WDMA) HYBRID OPTICAL LOCAL-AREA NETWORK USING OPTICAL ADD-DROP MULTIPLEXERS

A new kind of optical local area network (LAN), using a demand assign wavelength division multiple access (DA-WDMA) scheme, has been propose d. The proposed LAN consists of two parts; an ordinary standardized LA N and an overlaid network using wavelength division (WD) channels. The proposed network can provide bit-rate independent communication chann els on the ordinary LAN without limiting the capacities for the other channels. It also exhibits upgrade possibilities from present.standard ized networks. An access controller, which consists of software in add ition to the ordinary LAN controller, a digital signal processor (DSP) etc., was developed for DA-WDMA control. The network node operation h as been demonstrated using guided-wave acousto-optic (AO) mode convert ers as a tunable wavelength add-drop multiplexer (ADM).