Abstract: A transit device and system that include a first link configured to receive a plurality of packets, and a second link communicatively coupled to the first link via a slow protocol filter. The plurality of packets include a first type of packet (e.g., data packets) and a second type of packet (e.g., slow protocol control packets). The transit device also includes a slow protocol filter that couples the first link to the second link, with the slow protocol filter being coupled to a local slow protocol client (e.g., local host CPU). Moreover, the slow protocol filter is configured to receive the plurality of packets from the first link, and to determine whether each of the plurality of packets is of the first type or the second type. The slow protocol filter also is configured to transmit each of the plurality of packets that are of the first type to the second link, and to transmit each of the plurality of packets that are the second type to the local slow protocol client.

Abstract: Disclosed are an in-line monitoring apparatus, an optical receiver and a method for monitoring an input power of an optical signal in which one or more power monitoring stages, for example can measure the input power over an extended input power range. In one embodiment, an apparatus includes an avalanche photodiode (“APD”) configured to receive the optical signal and an input configured to bias the APD. It also includes one or more power monitoring stages coupled to the input in parallel with the APD for generating one or more measurement signals in-situ. In one embodiment, a range selector selects which one of the one or more power monitoring stages is to provide a measurement signal indicative of the input optical power. The power monitoring stages can provide for a wide range of linear current measurements as well as a range of measurable currents to monitor low-powered optical signals.

Abstract: Disclosed are an in-line monitoring apparatus with a temperature compensator, an optical receiver and a method for stabilizing gain of an avalanche photodiode (“APD”) over an extended range of input power values and across temperature variations. The apparatus can include one or more power monitoring stages coupled in parallel to the APD for generating one or more measurement signals in-situ. The apparatus also includes a temperature compensator configured to adjust an operational parameter for the APD as a function of temperature and the measurement signal. The temperature compensator adjusts the bias to maintain a substantially uniform gain across temperature variations to facilitate an increased sensitivity with which to monitor the input power at lower levels than if the temperature compensator did not adjust the bias in response to the temperature. One of the power monitoring stages can be configured to monitor the low-powered optical signals.

Abstract: An apparatus for pre-distorting a signal includes input nodes to receive an in-phase input signal and a quadrature input signal. Feedback nodes receive an in-phase feedback signal and a quadrature feedback signal. Output nodes transmit an in-phase pre-distorted signal and a quadrature pre-distorted signal. A Lagrange interpolation digital pre-distortion circuit is connected to the input nodes, the feedback nodes, and the output nodes. The Lagrange interpolation digital pre-distortion circuit is configured to perform a Lagrange interpolation on the in-phase input signal, the quadrature input signal, the in-phase feedback signal, and the quadrature feedback signal to produce the in-phase pre-distorted signal and the quadrature pre-distorted signal.

Abstract: The present invention is directed to an apparatus and a method of controlling a stacked switching system. The stacked switching system according to the present invention has a plurality of switches connected to each other through a network backplane. One of the switches in the stacked system is designated as the master unit, whereas the remaining switches are designated as the slave units. The present invention discloses two topology designs for assigning the master duties among the plurality of switches. The first topology design is termed as a fixed topology and the second topology design is termed as a dynamic topology. Both of these two topology designs assign the master control to the switch having the highest priority index. This master duties assignment is performed whenever there is a deletion or addition of switching unit to the system. For the fixed topology design, the master control assignment can only be performed after rebooting the system.