This paper outlines the developments of two kinds of Local Networks: the subscriber network for public communication and local area network for private communication It describes three kinds of network topologies: star

bus and ring. It explains

for the sake of ever-increasing capacity

optical fiber is the sole choice for transmission medium

although the optoelectronic devices set the limit of power and the electronics act as bottleneck for bit rate. The frequency devision multiple access using fiber star coupler has proven successful. both the tunable laser-heterodyne detection and the tunable filter-direct detection may be used. For data transmission

the packet switching would be more efficient than the circuit switching. In supplement to the synchronous optical fiber network

asynchronous transfer mode must be used for variable bit rate and burst data.