Abstract: An apparatus to test an Ethernet powered device includes a processor including a power negotiation supervisor, a DC power source, a first interface having an Ethernet medium dependent interface and a coupling circuit that inserts DC power onto one or more wire pairs of the first interface. The apparatus further includes a first bridging circuit, a measuring circuit to measure characteristics of DC power delivered to Ethernet powered device. The DC power source is configurable over a range of voltage levels including a plurality of operating voltages which are applied to the Ethernet powered device and the power negotiation supervisor processes power negotiation protocol messages.

Abstract: Systems to assess pair-to-pair unbalance characteristics of an Ethernet powered device (PD) and pair-to-pair unbalance characteristics of an Ethernet power source (PSE) include a controller, a pair of controlled electrical resistance circuits each having a DC current measurement circuit to measure pair-to-pair unbalance and a calibration circuit.

Abstract: Methods and apparatus provide for a system to measure transceiver parameters and test network interfaces at a physical layer without requiring specialized interface fixtures and excessive preparation and intervention.

Abstract: An apparatus for measuring characteristics of a at least one Power Over Ethernet (PoE) Power Sourcing Equipment (PSE) device (also referred to as a PSE test blade) is presented. The apparatus includes a port controller and a current loading circuit in communication with the port controller. The apparatus further includes a resistance loading circuit in communication with the port controller, a capacitance loading circuit in communication with the port controller, and a load current and voltage measuring circuit in communication with the port controller. The apparatus further includes a first network providing the power signals to at least one of the current loading circuit, the resistance loading circuit, the capacitance loading circuit, and the load current and voltage measuring circuit. The port controller utilizes a set of test primitives which are accessed in real time via a user interface to execute test sequences for characterizing PSE devices.

Abstract: A hydroacoustic communication system employs spread spectrum to mitigate multipath interference caused by acoustic reflections off underwater surfaces and other large boundaries or acoustic discontinuities. The system is particularly beneficial for mitigating errors due to surface reflections, and for mitigating interference due to unwanted signals having a delay ranging from tens of microseconds to hundreds of milliseconds.