On the space reuse efficiency of TSI-free OTDM rings

Design of future OTDM (Optical Time-Division Multiplexing) rings may require the network nodes to perform the time-slot interchange (TSI) function of moving data from an incoming time-slot to different outgoing time-slots. An efficient optical buffer technology for optical TSI is not currently available. Our previous work [1] has shown that without TSIs, all slots in an OTDM rings will form equal-length cycles. In this letter, we derive a general formula that shows the relationship between the cycle length and the space reuse efficiency of a TSI-free OTDM bi-directional ring