Abstract: A cost-effective continuous phase logic-based modulator and demodulator are provided to allow communications using binary frequency shift keying (BFSK) as well as M-ary FSK techniques. The modulator of the 1-bit precision modem architecture is based on a 1-bit precision numerically controlled oscillator (NCO), which provides complete programmability with respect to a frequency of the 1-bit precision logic-based modulator and/or demodulator. The 1-bit precision NCO includes an adder and a phase accumulator register which is clocked by a master clock signal. A two-input multiplexer has a single bit symbol value to generate BFSK, or larger input multiplexers can be implemented to provide M-ary FSK. The output of the 1-bit precision NCO is upconverted to an intermediate frequency using a simple logic function, i.e., XNOR logic. Alternatively, the intermediate frequency may be arrived at without the need for upconversion by directly utilizing a harmonic alias at a desired IF frequency.

Abstract: A line powered data access arrangement (DAA) is disclosed which adaptively allows proper operation with power supplied from a telephone line as conditions warrant, while at the same time satisfying the relevant requirements of many countries. In the line powered codec, a startup procedure for the international line powered codec uses register settings, e.g., country-specific register settings, which are powered and maintained from the low voltage side (e.g., from the PC or modem side) of the line powered codec. In this way, even during low line power conditions the programmed state of the line powered codec can be maintained, thus a default condition will not necessarily returned to by the line powered codec upon reset due to a power loss in the telephone line. In another aspect, a charge storage device such as a charge capacitor is charged from a charge pump formed from a differential clock signal from the low voltage side.

Abstract: A communications system includes a first device comprising a plurality of electrical-to-transmission medium converters, and a second device comprising a plurality of transmission medium-to-electrical converters to be connected to respective ones of the electrical-to-transmission medium converters via at least one transmission medium and defining parallel communications channels between the first and second devices, and wherein deskewing is provided. More particularly, the first device may include a string-based framing coder for determining and appending a string-based framing code to each information symbol string of information symbol strings to be transmitted in parallel over respective parallel communications channels. Each string-based framing code is based upon at least some of the information symbols in the respective information symbol string. The second device preferably comprises a deskewer for aligning received information symbol strings based upon the string-based framing codes.

Abstract: Apparatus and methods for adaptively, reliably, and accurately measuring the duration of an alerting or other signaling tone. A tone detector in accordance with the principles of the present invention accurately measures a duration of a tone burst (i.e., tone pulse) using a long frame length DFT and a short frame length DFT. Based on information obtained by the short frame length DFT, the long (i.e., standard) frame length DFT may be interrupted and reset to begin a new frame of data synchronized with the start of the next short frame corresponding to the processing by the short frame length DFT to minimize noise in the processing by the long frame length DFT and to greatly improve the resolution of the measurement of the duration of a particular tone to correspond to the lengths of the short frames used by the short frame length DFT.

Abstract: A phone number only messaging experience is provided in an Inter-Carrier Short Messaging System (IC-SMS) service. Subscriber to subscriber messages are routed between carrier's networks using an Inter-Carrier messaging module with appropriate MIN/carrier/carrier routing look-up capabilities. Short messages may be sent to a subscriber in another carrier's network addressed only with a phone number. If the recipient is outside of the sender's carrier network, the Inter-Carrier messaging module of the Inter-Carrier service provider (ICSP) determines the appropriate carrier for the recipient, appends the appropriate syntax to the short message to allow internet protocol (IP) or other standardized communication techniques between SMSCs of the two carriers, and routes the short message to the destination carrier. The recipient in the other carrier's network may reply back to the ICSP's sender using only the subscriber's directory number.

Abstract: Cordless telephone technology provides a long range and highly sophisticated wireless extension between a plurality of wireless piconet networks. In one embodiment, base units of separate cordless telephones include respective piconet front ends (e.g., Bluetooth protocol bearing RF front ends) in addition to the otherwise conventional RF front end. The piconet-capable base units are placed and made members of separate piconet networks, but within conventional cordless telephone range of one another, e.g., within one mile of one another. To allow communications between piconet devices on the separate wireless piconet networks, the cordless telephone base units pass piconet content information (i.e., the messages passed by a piconet device on a first piconet network including a first cordless telephone base unit intended for receipt by another piconet device on a second piconet network serviced by the other cordless telephone base unit.

Abstract: A digital phase locked loop (PLL) frequency synthesizer includes a 1-bit numerically controlled oscillator (NCO) to negate the requirement that a VCO frequency be an integer multiple of its reference frequency. Thus, in accordance with the principles of the present invention, a direct digital synthesizer (DDS) or numerically controlled oscillator (NCO) is used to form a frequency divider in a feedback path of a PLL. Thus, a synthesizer with fine frequency control and very fast settling time is disclosed. The conventional integer-ratio relationship between the reference frequency fREF and the synthesized output frequency signal fVCO is overcome by replacement of a conventional VCO divider in a feedback path of a digital PLL with a 1-bit NCO. This allows the reference frequency fREF to be greater than the channel spacing, i.e., the channel spacing can be smaller than the reference frequency fREF.

Abstract: A method and apparatus to perform a real-time drift correction of a remote handset's local oscillator in a digital cordless telephone. The remote handset begins in a standby (sniff) mode. The remote handset periodically wakes from a sleep mode and goes into a normal link verification mode. Once in the link verification mode, the remote handset enters a time division duplexing (TDD) mode and attempts to establish a link with a base unit based on the timing of the TDD data frame. After the remote handset establishes a link with the base unit, the remote handset requests a security word from the base unit. Upon receiving the requested security word, the remote handset determines if the requested security word matches a security word of the remote handset. The remote handset implements a software frequency adjustment of its local oscillator. Once per frame, the remote handset enters a timing recovery state where the current state of the frame is compared with a previous state.

Abstract: GPS satellites are culled into a minimum, preferred group having a longest dwell time within a cone of space, and communicated to mobile devices or subscribers within a particular region (e.g., serviced by a particular base station). The culling may initially be a list of GPS satellites visible to a particular base station at a particular time. As a preferred culling, only those GPS satellites currently within a cone of space above the relevant base station are selected for communication by a mobile device within the service area of the relevant base station. As an ultimate culling, a minimum set of GPS satellites may be selected based on, e.g., being not only within an arbitrary cone of space normal to the base station, but also projected to remain within that cone of space for the longest period of time, i.e., having the longest dwell time.

Abstract: An improved automatic frequency compensation (AFC) technique and apparatus is provided for piconet applications, e.g., BLUETOOTH™ applications. In particular, the present invention provides an offset normalizer which normalizes frequency offset against maximum deviations. By normalizing the frequency offset, before determination of an adjustment of a local oscillator, the local oscillator adjustment becomes uncorrelated with respect to gain along the receiving path (including in a demodulator). Thus, extremely precise adjustments can be made to the local oscillator in a piconet device to provide extremely precise automatic frequency compensation.

Abstract: An audible signal associated with an event is provided as part of the audio path of a telephone. In particular, a telephone according to one embodiment of the invention includes a microphone adapted to receive audible signals from a user and to convert the audible signals to electrical signals for transmission to a distant party, and a speaker adapted to receive electrical signals associated with input from the distant party and to convert the electrical signals to audible signals. According to the invention, the telephone also includes a processor adapted to produce electrical signals associated with an external event, and to integrate these electrical signals with the received electrical signals. In an alternative embodiment according to the invention, a method of alerting a party to a telephone conversation of an external event includes the step of providing an indication of the external event to the party from a speaker of the telephone during the telephone conversation.

Abstract: An AC impedance matching architecture which provides programmable AC impedance matching in a given range using a digital filter to filter a signal fed back from the impedance matched line to generate an AC impedance emulation control signal. The AC impedance emulation control signal is combined with a transmit signal (if desired) and drives a voltage controlled current source, which is in parallel with a reference impedance. A voltage is developed across the reference impedance to drive, e.g., the telephone line. The reference impedance is chosen based on a desired maximum AC impedance. The gain of the digital filter, a first order sigma delta filter in the disclosed embodiment, is chosen based on the desired value of the AC impedance. The transfer function of the digital filter is derived based on a desired AC impedance.

Abstract: Apparatus and method to transmit a speakerphone active indication signal to another party over a telephone line upon use of a speakerphone feature, and to transmit a speakerphone inactive indication signal upon cessation of the speakerphone feature. A speakerphone indication transmit module provides an audible or data signal relating to the activation or inactivation of a speakerphone feature to a receiving party's telephone system, which either audibly confirms use of the speakerphone at the opposite end, and/or displays a speakerphone active indication, e.g., on an LED or LCD display. The speakerphone indication active and inactive signals can be, e.g., a single tone, a DTMF tone, FSK signaling, or ADSL signaling.

Abstract: A method and apparatus for transferring convenience feature data (e.g., speed dial numbers, etc.) from one telephone to another local telephone within the same home or small office. In particular, the telephone includes a memory located within a corded or cordless telephone configured for storing data, and a transfer module configured to transfer requested data between the memory and a target device in response to a transfer request. The corded telephone utilizes a DTMF generator/receiver, a demodulation/modulation module, or a Bluetooth module to establish a communication path between the corded telephone and the target device. The cordless telephone utilizes a DTMF generator/receiver, a demodulation/modulation module, a radio frequency (RF) transceiver, or a Bluetooth module to establish a communication path between the cordless telephone and the target device.

Abstract: The present invention provides a circuit arrangement and technique for detecting any of a plurality of positions of a multi-position switch using a single input pin of a digital input/output device. Two specific embodiments are described relating to the use of a multi-position switch using a single digital input/output (DIO). In the first embodiment, a multi-position switch switches between various clock signals (e.g., pre-existing clock signals) on a circuit board, and inputs the same to the relevant pin of the. DIO device. In a variation of this embodiment, a second multi-position switch is connected in series with the first multi-position switch and varies the selected signal in a detectable and distinguishable way, e.g., by inverting or not inverting the signal selected by the first multi-position switch.

Abstract: An on-hook EOH indicating telephone includes a parallel set detector, an EOH signal detector, and an indication module to activate a configurable audible and/or visual alert indicating that another telephone is off-hook and should be hung up. The audible alert may be a unique ringing of the otherwise conventional ringer (e.g., every 5 minutes, at a unique cadence or frequency, etc.), or may be an audible tone output from the speaker of the on-hook EOH indicating telephone. The visible alert may be, e.g., a text message on a display of the on-hook EOH indicating telephone, a blinking, flashing, etc. of an LED, or other visible attention getting technique. When the central office presents the extended off-hook (EOH) notification signal to the desired telephone line, the invention-equipped telephone detects a parallel set in use, and then listens for the EOH signal.

Abstract: The present invention provides an architecture for a peripheral device to activate a breakpoint in a processor or other device under emulation. A peripheral breakpoint active signaler allows the peripheral to signal the occurrence of a breakpoint to the processor using a halt or trap line to the processor. This invention provides developers with increased code development capabilities by allowing them to set breakpoints in a peripheral device for the benefit of a processor interfaced with the peripheral to detect when a certain external event has occurred based on the perspective of a peripheral. A breakpoint control register individually enables breakpointing capability of each peripheral with respect to having the capability to halt the processor. Each peripheral has the capability to output a breakpoint request signal to set a bit in a breakpoint status register for readback by the processor, through an external port such as a JTAG test port, or other device.

Abstract: Clocks between at least two wireless devices are synchronized to reduce the need to transmit synchronization signals over a wireless communication channel therebetween. Two wireless devices synchronize their respective clocks with each other when each are electrically coupled, e.g., during a cradle time when brought into physical contact with each other through charge contacts, e.g., to recharge a remote portable unit. The charge signal appearing at the charge contacts is driven to create a time duration marked by a start transition and an end transition in the charge signal. The number of clock pulses of each of the two wireless devices during the time duration is counted, and compared to determine the difference in clock speeds of the wireless devices. The frequency of the clock of at least one of the wireless devices is adjusted to bring the difference in the clock speeds within a predetermined threshold tolerance level.

Abstract: A method to handle an incoming call to a target telephone that is engaged in a present call. A first signal to the target telephone indicates an incoming call, and a second signal to the calling telephone indicates that the target telephone is busy. Another method issues a first signal to a target telephone to indicate an incoming call. A ringback tone is issued to the calling telephone causing a speaker of the calling telephone to provide a ringing sound to the caller. A switch-hook signal from the target telephone indicates a desire of a user of the target telephone to place a party to the present call on hold, and to connect to the incoming call. A busy signal, is issued to the calling telephone causing its speaker to provide a busy sound if the switch-hook signal is not received by the time a variable reaches a predetermined limit.

Abstract: A networking device includes a legacy preamble injector that inserts a legacy preamble based on an indication that a legacy device is coupled to a common network. The legacy preamble injector inserts the legacy preamble if a legacy device is a target device for communication from a network appliance. Alternately, a device may be adapted to output a payload portion at a native rate, for example, if a legacy device is not a target. A Home Phone Line Network Alliance (HomePNA) system includes a telephone line network and a plurality of devices couple to the telephone line network. The plurality of devices may include at least one V2.x device and at least one V1.x device. The at least one V2.x device is adapted to recognize a presence on the telephone line network of at least one V1.x device, and to modify a transmission frame format based on this recognition.