Page 31: of Marine Technology Magazine (September 2014)

of this will be discussed in more detail later.

More devices could be added to our system by using multiple circulators. A ring is constructed using circulators connecting port 3 of each to port 1 of the next in a daisy chain confi gura- tion. Each port 2 would be routed to port 2 of an additional circulator that would route signals to and from the transceiver module’s transmit and receive ports. Each device on the ring would have its own address and would retransmit any signal that was not addressed to it. This confi guration also makes it possible for the devices to communicate with one another as well as with the support vessel, all through a single fi ber con- nector or penetrator.

The drawback to this architecture is latency in the network.

The maximum data throughput rate is limited to that of the slowest transceiver in the system. This is acceptable if there is no requirement for simultaneous communications over the network. However, if there is such a requirement, or if one or more of the devices cannot cache its data for transmission when the network is available, then dense wavelength divi- sional multiplexing (DWDM) offers an approach that will al- low for simultaneous communications in the network.

With DWDM, multiple wavelengths, or colors, of light are (L-R) BIRNS Millennium 3O Dual O-ring Receptacle (OR) with four optical fi bers, 3T fl anged receptacle (FR) with two optical fi bers and 3O FR with four optical fi bers have a small footprint but offer sig- nifi cant versatility in data transference and spare capability for future subsea system upgrades.

Marine Technology Reporter 31 www.marinetechnologynews.com

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