Abstract: Transmitting a pre-recorded announcement to the user of an network interface unit (NIU) each time the user places a telephone call if an alarm is set because a battery in an uninterruptible power supply (UPS) is in a low power state. The pre-recorded announcement states that the battery needs to be replaced. The user is given a simple procedure for contacting service personnel at a service center to have the battery replaced in the UPS. In addition, this announcement is overridden if the user starts to dial the emergency telephone number (911). This allows the user to gain immediate access to the emergency telephone number without having to listen to the message stating that the battery in the UPS needs to be replaced. An indicator is also set on NIU upon the battery being in the low power state. If a call is completed to the service center, the alarm is reset for a predetermined amount of time to give the service personnel time to service the battery.

Abstract: An optical wavelength cross connect is provided to receive multiple input optical signals that each have multiple spectral bands and to transmit multiple output optical signals that each have one or more of those spectral bands. The optical wavelength cross connect includes multiple wavelength routing elements, which are optical components that selectively route wavelength components between one optical signal and multiple optical signals in either direction according to a configurable state. As used within the optical wavelength cross connect, each of the wavelength routing elements receives at least one optical signal corresponding to one of the input optical signals. A mapping of the spectral bands to the output optical signals is determined by the states of the wavelength routing elements.

Abstract: Methods are provided for upgrading a Ki1×Kj1 optical wavelength cross connect to a Kl2×Kj2 optical wavelength cross connect without taking the cross connect out of service. Each Kl×Kj cross connects has a working fabric with multiple optical components and has a protection fabric. The working fabric receives optical traffic from Kl input optical signals and transmits Kj output optical signals. The protection fabric is configured to bypass at least one of the optical components in the event of a fault. The upgrade of the Kl1×Kj1 optical wavelength cross connect proceeds by upgrading the protection fabric to accommodate at least Ki2 input optical signals. Sequentially, each of the optical components included on the working fabric is upgraded. The optical traffic received by that optical component is bypassed to the protection fabric. Thereafter, that optical component is upgraded to accommodate at least Kl2 input optical signals.

Abstract: An optical ring is provided for propagating optical signal pairs over wavelength connections between nodes. Each optical signal pair includes two signals at different wavelengths. At one or more of the nodes, one signal of the pair acts as a transmit signal and the other acts as a receive signal. If a failure is detected the optical signal pair is redirected over a protection path without changing the wavelengths of the transmit and receive signals. This may be achieved by reversing a propagation direction for each of the signals comprised by the redirected optical signal pair.

Abstract: The present invention provides a media terminal adaptor having an internal logical interface to permit communication connections to be established between ports of the MTA.

Abstract: The distributed broadband cable modem termination system centralizes the point to multi-point function of the downstream signaling while simultaneously localizing the multi-point to single point functions of the upstream signaling. The upstream broadband cable termination segment of the broadband cable modem termination system is located at a different layer of the broadband cable network from the downstream broadband cable modem termination segment of the broadband cable modem termination system. By splitting the broadband cable modem termination system functions into separable and independently operable upstream and downstream functions, network deployment is optimized for a number of reasons. The downstream and upstream functions scale independently so the system can selectively add capacity where needed in the direction needed independent of the capacity in the reverse direction.

Abstract: A switching network having a plurality of independent switching groups with each switching group capable of switching one bit of each group of data from external data links through a telecommunication switching system and port units interfacing the data links directly control which of the switching groups will be active. This allows extra switching groups to be utilized as replacement switching groups should a switching group actively switching a bit of the incoming data be disabled. This increases the overall reliability of the telecommunication switching system since a failure of a port unit will only effect the external data link that is connected to that unit. In addition, this eliminates complicated and centralized control for the switching units which would be needed to inform the switching units which units should be active and the bit a given switching unit should be communicating.

Abstract: A switching network having a plurality of independent switching units with each switching unit switching one bit of each group of data from external data links through a telecommunication switching system. The plurality of switching units is greater than the number of bits that must be switched which increases reliability. This allows the extra switching units to be utilized as replacement switching units should a switching unit actively switching a bit of the incoming data be disabled. The switching units provide full broadcast switching of data from any individual external link to any number of the other external links. A plurality of port units terminate the external links, and a plurality of control paths are provide from a central controller to each of the port units. Each of the switching units communicated one of the control paths. For control, each port unit determines a set of control information that is identical from a majority of the control paths.

Abstract: A control circuit for receiving clock signals from duplicated sources, such as a pair of Time Slot Interchanges (TSI) and for normally extending the clock signal of the on-line source to clock signal utilization devices, such as digital port boards. The control circuit contains circuitry which ensures that no spurious pulses are applied to the port boards when the TSIs interchange their on-line/off-line status.