Abstract: An apparatus or corresponding method of managing Plain Old Telephone Service (POTS) lines in a Passive Optical Network (PON) to prevent an alarm system from generating an alarm during a software upgrade or maintenance of an Optical Network Terminal (ONT), Optical Line Terminal (OLT), or PON while maintaining the effectiveness of the alarm system. The ONT may store data related to a POTS line in nonvolatile memory. The ONT may activate the POTS line based on the data from the nonvolatile memory in an event of interruption in communications with an OLT prior to reestablishing communications with the OLT. The interruption in communications may be caused by an ONT reboot to complete an installation of a software upgrade. The ONT may energize the POTS line with a voltage in response to activating the POTS line to prevent the alarm system from generating the alarm.

Abstract: An apparatus for controlling access to a time division multiplexed (TDM) bus includes a frame address register having a plurality of storage registers for storing a plurality of frame addresses designated for use in communicating over said TDM bus. A frame address latch stores a current frame address. A frame comparator, coupled to the frame address register and the frame address latch, compares the designated frame addresses with the current frame address and produces a first signal indicative of the storage register containing a frame address matching the current frame address. A time slot register has a plurality of storage registers for storing a time slot number designated for use in communicating over said TDM bus. A time slot generator generates a current time slot number.

Abstract: A multi-port (multiplexed) modem for implementing automatic reconfiguration of the ports so that transmission bandwidth can be optimized. The modem utilizes a sequence of communications and acknowledgments transmitted over the donor port donating the bandwidth and the recipient port receiving the bandwidth. This allows reconfiguration of the modem ports without need for interruption of the unaffected ports and requires no secondary channel to implement. Only the port going idle and the port receiving the bandwidth are affected so that communication channel throughput is maximized and unaffected ports are not interrupted.

Abstract: A method for changing the data transmission rates in a synchronous data communication system including a first modem and a second modem coupled together through a transmission channel, the transmission channel including a first path for transmissions from the first modem to the second modem and a second path for transmission from the second modem to the first modem, includes the steps of determining, at the first modem, that the second path of the transmission channel is adequately high in quality to support an increase in transmission rate. Next it is determined, at the second modem, that the first path of the transmission channel is adequately high in quality to support an increase in transmission rate. A training sequence is then transmitted at an increased transmission rate from the second modem to the first modem. Next, a training sequence is transmitted at the increased transmission rate from the first modem to the second modem.

Abstract: Disclosed is a modulation-demodulation system and method for transmitting a plurality of sequentially received information bit sequences, the system including a transmitter having a state machine for expanding by a coding process each information bit sequence into an expanded bit sequence with a coded bit group portion and, in some cases, an uncoded bit group portion. The transmitter further includes a modulator for modulating a carrier signal by one of a plurality of multilevel symbols in a two-dimensional complex plane in response to each sequentially applied expanded bit sequence, with the coded bit group portion being used to specify a subset of the multilevel symbols which when rotated in the complex plane maps upon another subset for each adverse angular rotation and the uncoded bit group portion being used to specify for a selected multiple symbol subset the transmitted multilevel symbol of the carrier signal.

Abstract: Disclosed is a modulation-demodulation system and method for transmitting a plurality of sequentially received information bit sequences, the system including a transmitter having a state machine for expanding by a coding process each information bit sequence into an expanded bit sequence with a coded bit group portion and, in some cases, an uncoded bit group portion. The transmitter further includes a modulator for modulating a carrier signal by one of a plurality of multilevel symbols in a two-dimensional complex plane in response to each sequentially applied expanded bit sequence, with the coded bit group portion being used to specify a subset of the multilevel symbols which when rotated in the complex plane maps upon another subset for each adverse angular rotation and the uncoded bit group portion being used to specify for a selected multiple symbol subset the transmitted multilevel symbol of the carrier signal.