Access protocols for passive optical star networks

Through Wavelength Division Multiplexing (WDM), the huge bandwidth of optical fiber can be divided into a set of high-speed logical channels. A passive star coupler can be used to configure a multichannel network with these WDM channels. The users in these networks have access to one or more channels. Hence, one of the major issues in these networks is the channel access protocols users have to follow in order to transmit their packets to other users. This paper reviews many of the proposed protocols that appeared in the literature. These protocol are divided into three different categories: fixed assignment (or pre-allocation) protocols, random access protocols and hybrid protocols. The random access protocols are further divided into reservation, switching and collision avoidance protocols.