摘要:
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. When the cumulative timing slip is greater than a designated threshold, a frequency adjustment is made. During this exchange of commands between the remote handset and base unit, the remote handset continuously adjusts its local oscillator to achieve frequency alignment within, e.g., 1 part per million (ppm). Alternatively, frequency alignment may be achieved to a specified value.
摘要:
When a plurality of cordless telephones (e.g., digital cordless telephones) are used within range of one another, base units of one or more of the digital cordless telephones may receive transmissions from others of the digital cordless telephones. Conventionally, the base unit would simply ignore information relating to that received from an unintended remote handset, i.e., a remote handset having a security code which fails to match that of the receiving base unit. However, in accordance with the principles of the present invention, information regarding the unique security code received with respect to other remote handsets (i.e., those having security codes which do not match that of the receiving base unit), are logged and used in a way which provides a unique best available channel list to each of the digital cordless telephones so that similar digital cordless telephones operating in a similar environment do not attempt selection of channels in a similar way (causing channel inclarity and/or interference). In a first embodiment, the list of best available channels is randomized based on the unique security code of the relevant digital cordless telephone. In a second embodiment, the list of best available channels is randomized only when another digital cordless telephone becomes within transmission range of the relevant digital cordless telephone. In a third embodiment, a list of best available channels is uniquely indexed for each digital cordless telephone based on a ranking of the digital cordless telephones within transmission range of one another. For instance, the highest ranking digital telephone in an environment with three digital cordless telephones attempts use of, preferably in order, the 1st, 4th, 7th, 10th, etc. channels.
摘要:
The present invention provides a device for connecting a power supply to a rechargeable device, in which a detection unit is adapted to detect power levels of a battery to output a first signal when a low power level of the battery is detected, and a second signal when a sufficient power level of the battery is detected. A power control unit is adapted to receive the first and second signals, and to disconnect circuitry in the rechargeable device from the battery when the first signal is asserted, and to connect the circuitry in the rechargeable device to the battery when the second signal is asserted.
摘要:
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. In another embodiment, a multi-position switch switches between nodes of a series chain of resistors to produce a change to an RC circuit that will respond differently to a step change to the input depending upon the position of the multi-position switch. In either case, the positions of a multi-position (i.e., at least two position) switch can be detected using only one input pin of a digital input/output device.
摘要:
A system for, and method of, determining a condition of a battery and telecommunications equipment incorporating the system or the method. In one embodiment, the system includes: (1) a load controller, having a memory, that couples a load of a known magnitude to the battery and (2) a voltage monitor, coupled to the load controller, that measures voltages of the battery at first and second times and provides the voltages to the load controller, the load controller comparing a slope defined by the voltages to a model stored in the memory and regarding the battery to determine a condition thereof.
摘要:
Proximity regulation systems for use with a portable cell phone and portable cell phones are disclosed. In one embodiment, the portable cell phone includes: (1) an operation mode input or circuit and (2) means for determining a transmit power level of the portable cell phone based on the operation mode input or circuit.
摘要:
Proximity regulation systems for use with a portable cell phone and portable cell phones are disclosed. In one embodiment, a portable cell phone includes a proximity regulation system having a location sensing subsystem configured to determine a location of a portable cell phone proximate a user by determining a mode of operation of the portable cell phone. A power governing subsystem is coupled to the location sensing subsystem and configured to determine a proximity transmit power level of the portable cell phone based on the location.
摘要:
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.
摘要:
Proximity regulation systems for use with a portable cell phone and portable cell phones are disclosed. In one embodiment, the portable cell phone includes: (1) an operation mode input or circuit and (2) means for determining a transmit power level of the portable cell phone based on the operation mode input or circuit.
摘要:
Proximity regulation systems for use with a portable cell phone, a portable cell phone and a method of operating the same. In one embodiment, the proximity regulation system includes a location sensing subsystem configured to determine a location of a portable cell phone proximate a user by determining a mode of operation of the portable cell phone. A power governing subsystem is coupled to the location sensing subsystem and configured to determine a proximity transmit power level of the portable cell phone based on the location.