Scalable Fractional Lambda Switching: A Testbed

Synchronization in a Random Length Ring Network for SDN-Controlled Optical TDM Switching

“…If the clock is distributed along the same fiber infrastructure used for data transmission, then the clock received at each node will be delayed exactly by the propagation delay between the node that distributes the clock and the receiving node. Another way is to distribute the same clock to all nodes by for example using local network for clock distribution [6] or the Global Positioning System (GPS) [7] allowing for the same time reference to exist in each node, however not accounting for the link propagation delay among nodes in the network.…”

“…Other examples exploit global synchronization with preengineered fiber link lengths and use either GPS [7] or a master clock reference [6,9] that is distributed in the network, without accounting for the propagation delay among nodes. Even though theoretically this enables accurate operation, in practice it introduces severe limitations on the network flexibility, planning and maintenance as fiber lengths must be accurately controlled.…”

Cognitive Routing in Converged Access-Metro Environment via $\lambda$-Selective SOA-MZI Switch

“…The cross-phase modulation between the data signal and a control pulse is thereby used to switch the data to one of the two interferometer ports. A variety of SOA-or SOA-MZI based switches has been presented in earlier works, including label switching with headers or signalling at auxiliary wavelengths [4]- [7], showing also cascaded operation at high data rate [8].…”

Contention avoidance in bufferless slotted optical packet switched networks with egress switch coordination

“…Our objective is to reduce overall PLR in core switches by using optical slot reservation in buffer-less slotted-OPS network while controlling buffer size and buffering delay in ingress switches. Fractional lambda switching (FλS) [23,24] is a dynamic all-optical switching technique where fractions of wavelengths called time frames are dynamically switched in core switches based on reservation tables in them. In FλS, a common-time-reference such as global positioning system (GPS) is used in all core switches to synchronize their time frames.…”

“…This lets the FλS to reserve resources for each flow at the network. However, FλS has been designed for circuit based traffic and it needs common-timereference in all core/edge switches [23,24]. We want to reserve optical slots in buffer-less OPS network without using common-time-reference.…”