Abstract: Lower bandwidth technology is used to determine whether a communication channel can support higher bandwidth technology. A signal generator generates a series of test signals that are associated with the higher bandwidth technology. The test signals are sampled to produce aliases that can be analyzed with lower bandwidth technology. Modem parameters are accessed from a modem's memory. The modem parameters are compared with a database containing information about whether a set of modem parameters indicates that a telephone local can support broadband devices.

Abstract: Lower bandwidth technology is used to determine whether a communication channel can support higher bandwidth technology. A signal generator generates a series of test signals that are associated with the higher bandwidth technology. The test signals are sampled to produce aliases that can be analyzed with lower bandwidth technology. Modem parameters are accessed from a modem's memory. The modem parameters are compared with a database containing information about whether a set of modem parameters indicates that a telephone local can support broadband devices.

Abstract: A high speed processor for a digital modem which transmits and receives data over voice grade telephone lines, for performing logical addition and subtraction operations during encoding and decoding of data as phase shift keyed modulation. A quarter square multiplying circuit is provided which executes multiplying operations at high speed. A discrete-input multiplexer is provided and controlled to bring single-bit variables into the processor as word variables permitting logic operations to be performed rapidly and efficiently. A bitwise logic circuit is provided in conjunction with the multiplexer and the processor to perform logic operations on bit pairs within the same word or on pairs of bits from different locations in two different operands. An interrupt subsystem includes a toggle circuit which alternately monitors for transmit and receive interrupts.

Abstract: A memory device is constructed having a plurality of output ports, each output port being one word wide, such that a plurality of words may be accessed from the memory simultaneously.

Abstract: A digital modem comprising a discrete analog/digital converter and digital processor for high-speed digital data transmission by means of analog signals over analog transmission facilities. The analog/digital converter comprises a transmitter section including a digital-to-analog converter and an analog matching interface, and a receiver section including an analog matching interface and analog-to-digital converter. The digital processor comprises a signal processor set, a processor control set and a multiplier/memory set capable of digital manipulation and computation of digitized data signals to accomplish the required encoding, filtering, modulation, demodulation, equalization, decoding and control function.