Abstract: A routing system and method for flows within a network provides multicast flow transport for one or more groups. Transit routers comprising processing units that run overlay processes route one or more flows based on overlay group identifiers. Access nodes issue requests for overlay groups in order to receive flows from the transit routers. The overlay processes utilize a mapping service that maps overlay group identifiers to native multicast group identifiers. A control channel between the access nodes and transit routers is used for communicating access nodes requests, overlay group identifiers, and native multicast group identifiers.

Abstract: A routing system and method for flows within a network provides multicast flow transport for one or more groups. Transit routers comprising processing units that run overlay processes route one or more flows based on overlay group identifiers. Access nodes issue requests for overlay groups in order to receive flows from the transit routers. The overlay processes utilize a mapping service that maps overlay group identifiers to native multicast group identifiers. A control channel between the access nodes and transit routers is used for communicating access nodes requests, overlay group identifiers, and native multicast group identifiers.

Abstract: As disclosed herein, a new and improved method and apparatus provide for fine tuning the position of a servomotor used to drive a transducer mounted on an ultrasound probe to a desired position. This improvement is accomplished by processing the analog quadrature output signals of an incremental optical encoder, coupled to the servomotor. The improvement uses the positional information derived from the analog quadrature output signals. The analog quadrature output signals, defined as sine and cosine, are converted to digital square waves. The digital square waves are decoded to produce digital position quadrants, wherein each quadrant represents a specific motor position. The corresponding digital square waves are also decoded by a logic array device and coupled to the select input of an analog switch.