WO1995010153A1

WO1995010153A1 - Method and apparatus for maximizing the battery life in cordless telephones

Info

Publication number: WO1995010153A1
Application number: PCT/US1994/011019
Authority: WO
Inventors: Joseph T. Lipowski; F. Matthew Rhodes; James E. Petranovich; Bjorn E. Bjerede; Terrance Raymond Bourk
Original assignee: Pacific Communication Sciences Inc
Current assignee: Cirrus Logic Inc
Priority date: 1993-10-01
Filing date: 1994-09-27
Publication date: 1995-04-13
Anticipated expiration: 1996-04-01
Also published as: AU7922094A

Abstract

Methods and apparatus for reducing the power usage of a cordless phone (18) by reducing the power usage of components of the cordless phone as a function of a low power, low frequency oscillator (48), transmit time slots of a time division duplex format signal, receive time slots of a time division duplex format signal, quality of a signal transmitted by the cordless phone (18), or strength of a signal received by a cordless phone (18).

Description

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METHOD AND APPARATUS FOR MAXIMIZING THE BATTERY LIFE

IN CORDLESS TELEPHONES

Cross-Reference to Related Applications

This application is related to co-pending application 5 Serial No. 08/013,625, filed February 2, 1993 (Attorney's Docket No. PACI-0105) , which is assigned to the same assignee and is incorporated herein by reference.

Field of the Invention

The present invention relates generally to cordless 10 telephone systems and more particularly to power saving techniques for cordless telephone systems.

Background of the Invention

Presently, cordless telephone systems generate speech representative signals using analog techniques and digital

15 techniques, where the digital signal is then converted into analog form for transmission. The phones using digital techniques have been referred to as digital cordless telephones (DCT) or Personal Hand-Phones (PHP) .

As used herein, cordless telephone or digital cordless

20 telephone (DCT) refers to those systems intended for home, public or office use. Such systems typically include a battery powered portable station (handset) and a base station, with the base station being connected into the public telecommunication network. Although the invention may also find use in analog cordless, cellular, or mobile phone systems, it is described herein in relation to only digital cordless phone systems.

Transmission standards or specifications have already been developed in both Japan and Europe for use in designing DCT systems. Each of the transmission standards are based on the use of a time division duplex (TDD) format, employing time division duplex for two-way communication. For purposes of illustration herein, the Japanese standards will be emphasized. However, it is noted that the invention will have utility with any transmission standard including current analog cordless phone system standards and is therefore not limited to use solely with the Japanese standard.

The Japanese DCT transmission standard specifies the use of a plurality of individual carrier signals having a frequency separation of 300 kHz within an overall system bandwidth of about 23 MHz between approximately 1,895 MHz to 1,918 MHz. Each carrier signal should support four channels in a TDMA format employing time division duplex for two-way communication. In particular, for each frame of time (5 ms) there are four transmit time slots (one for each channel) and four receive time slots (one for each channel) . Each slot is approximately 625 μs long with a guard time of approximately 30 μs provided within each slot.

Under the Japanese standard, speech representative signals are to be generated using a known digital technique, namely, the adaptive pulse code modulation (ADPCM) technique. The ADPCM signal is thereafter used to generate a digital modulated signal. The modulation scheme specified in the Japanese standard is the differential π/4-QPSK (π/4-quadrature phase shift keying) scheme with square root raised cosine filtering. It will be appreciated that such a scheme permits the transmission of digital data (Is and 0s) using a minimum number of bits. Digital data generated by this scheme is to be transmitted at a rate of 384 kHz which, in view of the modulation scheme, corresponds to a symbol transmission rate of

192 kHz. By contrast, the European DCT system specifies a series of carriers spaced 1.728 MHz apart within an overall bandwidth of approximately 17.28 MHz. Each carrier is to support twelve full duplex channels, i.e., 12 slots for transmission and 12 slots for reception.

In order to modulate and demodulate the signals sent and received by a DCT phone, the unit may generate one or more high frequency signals, generally by the use of voltage controlled oscillators which may entail a significant current drain on the battery of a DCT. A cordless phone, whether digital or analog, also has other significant current draining functions. Cordless phones may amplify an incoming signal sent from a base station or amplify a signal generated by the phone and sent to a base station. This function is generally performed by one or more amplifiers which provide significant current drain on a battery. Finally, when a phone is not in use for voice communications, the phone may monitor paging signals from base stations to determine whether there is a call or intercom page for the phone. The receiver circuitry of the phone must then listen for the paging signals and this process may also provide a significant current drain on a battery. Each of the above mentioned functions, i.e., generating high frequency signals, amplifying signals, and monitoring for paging signals, may provide a significant current drain on a battery. As a consequence, the continuous use time of a DCT or any cordless phone as well as the standby mode time of a phone where the phone is monitoring paging signals is limited. The phone battery must then be replaced or recharged as a result of current drain caused by the above mentioned functions.

Accordingly, a need exists for a cordless telephone system that can reduce the current drain of a battery for the functions of generating high frequency signals, amplifying signals, and monitoring for paging signals. - A -

Summary of the Invention

The previously described problems are overcome and the objects and advantages of the invention are achieved in apparatus and methods for cordless telephone systems in which power usage is reduced. The method includes the steps of reducing power usage of at least one component of the cordless phone while monitoring cycles produced by a low power, low frequency local oscillator, then determining when the number of cycles produced by the local oscillator equals a predetermined number, and increasing power usage of at least one component of the cordless phone as when the number of cycles produced by the frequency oscillator equals the predetermined number.

This method may further include the steps of determining whether the number of cycles produced by the frequency oscillator is equal to a second predetermined number and then increasing the power usage of at least one other component of the cordless phone based on this determination.

Specifically, increasing the power usage of signal receiving components of the cordless phone when the number of cycles produced by the frequency oscillator equals the predetermined number.

This method may also include the steps of determining whether the number of cycles produced by the frequency oscillator is equal to a second predetermined number, while detecting via the signal receiving components whether a predetermined signal has been received. In such a method, all the previously mentioned steps are repeated as a function of whether the number of cycles produced by the frequency oscillator equals the second predetermined number and as a function of the signal receiving components of the cordless phone detecting the predetermined signal.

The invention also includes method and apparatus for reducing power usage of a cordless phone during a call where the cordless phone sends signals in a time division duplex format having a plurality of transmit time slots. The method includes the steps of determining whether a signal is to be inserted in a particular transmit time slot by the cordless phone and reducing power usage of components of the cordless phone until the signal is to be inserted in the particular transmit time slot by the cordless phone.

In another embodiment of the invention, power usage of a cordless phone is reduced during a call where the cordless phone receives signals in a time division duplex format having a plurality of receive time slots. This method includes the steps of determining whether a signal is to be copied from a particular receive time slot by the cordless phone and reducing power usage of components of the cordless phone until the signal is to be copied from the particular receive time slot.

This method may also include the steps of determining whether a signal is to be inserted in a particular transmit time slot and reducing power usage of components of the cordless phone until the signal is to be inserted in the particular transmit time slot.

In another embodiment of the invention, power usage is reduced during a call where the cordless phone receives signals indicating the quality of signals transmitted by the cordless phone. The method includes the steps of determining, in relation to the quality indicating, whether the strength of signals transmitted from the cordless phone can be reduced and thereafter reducing the power usage of components in order to reduce the strength of transmitted signals based on such a determination.

In another embodiment of the invention, power usage is reduced during a call by receiving a signal, determining the strength of the received signal, determining whether the strength of received signal is acceptable, and adjusting the strength of the received signal based on the determination of whether the received signal is acceptable.

This method may also include the steps of determining, in relation to received quality indicating, whether the strength of signals transmitted from the cordless phone can be reduced and thereafter reducing power usage of components of the cordless phone to reduce the strength of transmitted signals based on this determination. Brief Description of the Drawings

The present invention will be better understood, and its numerous objects and advantages will become apparent by reference to the following detailed description of the invention when taken in conjunction with the following drawings, in which:

Fig. 1 is a block diagram of a digital cordless telephone system constructed in accordance with the present invention; Fig. 2 is block diagram of the core components of a portable station depicted in Fig. 1;

Fig. 3 is block diagram of a portion of the components of Fig. 2, modified so the components now form the core of a base station depicted in Fig. 1; Fig. 4 is a generalized schematic showing the operation of the base band processor depicted in Fig. 2;

Fig. 5 is a generalized schematic diagram of the IF processor block depicted in Fig. 2;

Fig. 6 is a generalized schematic diagram of the RF processor block depicted in Fig. 2;

Fig. 7 is a generalized schematic diagram of the Amp/Switch block depicted in Fig. 2;

Fig. 8 is a more detailed schematic of the IF block depicted in Fig. 2; and

Detailed Description

A DCT system constructed in accordance with the present invention is shown in Fig. 1 and generally designated 10. DCT system 10 is shown to include two base stations 12 and 14, each of which are adapted for connection to public telecommunications network 16. Portable stations or cordless phones 18 and 20, associated with base station 12, and portable stations or cordless phones 22 and 24, associated with base station 14, provide two-way cordless communication, i.e. a person using portable station 18 can have a conversation with a person using portable station 24. It is noted that portable stations 18 through 24 are preferably in the form of a battery- operated handset.

It will be appreciated that base station 12 and cordless phones or handsets 18 and 20 may be physically located several miles from base station 14 and portable stations 22 and 24. The distance between base stations is only limited by the capabilities of network 16. Although the invention may be useful in cordless phones capable of transmitting signals over several miles, it is described herein in terms of units adapted for transmitting signals within about 100 feet between base station and portable station. Additionally, although the present invention may be useful in portable stations which are capable of communicating directly with other portable stations, the invention is described herein in terms of portable stations engaging in two-way communication via their associated base stations.

The invention will be described herein in terms of its use in the Japanese Personal Hand-Phone (PHP) system specification described previously. It will be recalled that the Japanese standard specifies the use of a plurality of individual carrier signals having a frequency separation of at least 300 kHz within an overall system bandwidth of about 23 MHz between approximately 1,895 MHz to 1,918 MHz. Each carrier signal should support four channels in a TDD format employing time division duplex for two-way communication.

It is noted that the internal structure of handsets 18 through 24 are identical, i.e. only the frequencies or time slots at which these handsets transmit and receive will be different. Consequently, only the internal structure of portable station 24 will be described. Such internal structure is generally depicted in Fig. 2.

One aspect of the present invention is the interaction of a portable station 24 with a base station 14 when portable station 24 is not currently in use, i.e., a call is not in progress. When a call is not in progress, portable station 24 may be placed in a monitor mode to listen for paging signals from the base station 14 indicating that a call is being initiated with portable station 24. The base station 14 may only produce paging signals, if any, depending on whether a call is to be initiated, at predefined intervals. In the preferred embodiment of the present invention, the base station will produce a paging signal, if any, during one second intervals.

As a consequence, portable station 24 need only listen for the paging signal at or about the boundary of the one second interval. In accordance with this requirement and as shown in Figure 2, the present invention includes a low frequency oscillator 31 which is a low power oscillator running at a frequency considerably lower than the other oscillators in portable station 24 and thus requiring considerably less current or power usage than such other oscillators. In the present invention, when portable station 24 is in monitor mode, components of portable station 24 are placed in a sleep mode where they draw little or no power. The low frequency oscillator 31 and a base band processor 26 (shown in Figure 4) are used to first place components in sleep or reduced power usage mode. Then the base band processor 26 is used to monitor the output of the low frequency oscillator 31 by observing the cycles produced by the low frequency oscillator. In another aspect of the present invention, all the components of the IF processor 28 have reduced power usage when in sleep mode except for a reference divider 101 which provides a reference clock signal for the base band processor 26 and keyboard processor 44. As explained in more detail below, this mode may occur when a user of the portable station 24 is using the keyboard to perform a function other than initiating a call such as programming numbers in a memory (not shown) .

By monitoring the cycles generated by the low frequency oscillator, the base band processor 26 can determine whether the boundary of the one second paging interval is approaching by comparing the number of cycles generated to a first predetermined number and then awaken or increase the power usage of components of portable station 24. In the preferred embodiment of the present invention, the base band processor 26 only awakens or increases power to the components of portable station 24 needed to receive and process a possible paging signal that may be produced by the base station 14. In a further preferred embodiment of the invention, the base band processor 26 first increases the power usage of a first set of components when the number of cycles equals the first predetermined number and then awakens a second set of components when the number of cycles equals a second predetermined number where the second predetermined number is greater than the first predetermined number. After the boundary has passed, the base band processor 26 can then place the awakened components back to sleep, i.e., reduce their power usage, if a paging signal was not received. If a paging signal was received, the base band processor 26 can awaken other components to enable full communication between portable station 24 and the base station 14. This aspect of the present invention is described in more detail below.

According to another aspect of the present invention, once a call is initiated by either portable station 24 or base station 14, components are placed in standby mode where their power usage is reduced as a function of the time division duplex format of the communication channel between portable station 24 and the base station 14. As noted above, the communication channel uses a time division duplex format where the signal is divided into four channels, or eight time slots, four receive time slots and four transmit time slots in the preferred embodiment of the present invention. Portable station 24 in the preferred embodiment of the present invention only uses one receive time slot and one transmit time slot during any call. As a consequence, portable station 24 does not need to process the segments of the time frame which represent the other three transmit and receive time slots.

In the preferred embodiment of the present invention, portable station also has certain components that are only used in transmit operations and certain components that are used in receive operations. As a consequence, those components only need be active during one of the eight time slots in a time frame. The present invention reduces the power usage of portable station 24 by reducing the power usage of these components and other components during the time slots when they are not processing a signal. In particular, the receive components copy the information or content of one of the eight time slots in the signal. In between this one time slot, the base band processor 26 places components in standby mode until the next receive time slot. Likewise, the transmit components insert information into only one of four transmit slots or one of the eight total time slots in the signal. In between this one transmit time slot, the base band processor 26 places components in standby mode until the next transmit time slot. This aspect of the invention will also be described in more detail below.

According to another aspect of the present invention, portable station 24 may use voice activated control or VOX to reduce the power usage of components. If the user of portable station is not speaking, such as when listening to the received signal, portable station may not insert any information into its corresponding transmit time slot and thus keep components in standby mode until the user of portable station starts speaking again.

According to another aspect of the present invention, portable station 24 can control the power level or strength of the signal it transmits. The base station 14 may transmit information in the received signal time slot for portable station 24 which indicates the quality of the signal received from portable station 24. Depending on the quality or strength of the signal, portable station may lower the amplification level of the transmission signal. This may occur, for example, when portable station is physically close to the base station 14.

According to a final aspect of the present invention, portable station 24 may reduce the power usage of components by monitoring the quality or strength of the received signal in its corresponding time slot. If the received signal is of a certain quality or strength, portable station 24 may not need amplify to the signal in order to process it, in fact, the portable station may attenuate, instead of amplify, the signal. The signal may be attenuated when portable station 24 is close to the base station 14.

According to other aspects of the present invention, any and all of the above aspects of the present invention can be used in a single portable station system to reduce the power usage of components during operations of the portable station, i.e., when the portable station is in monitor mode, transmit mode or receive mode. These aspects of the present invention are described in more detail below with reference to the preferred embodiment of the present invention.

In the preferred embodiment of present invention, the core of portable station 24 is an integrated circuit chip set including chips or processors 26, 28, 30 and 32 along with the low frequency oscillator 31. Before giving a detailed description of the structure of each chip, consider generally the operation of processors 26 through 32 during a transmit and receive operation. During transmission, base band processor 26 receives a voice signal and operates to convert the voice signal into a digital signal having a desired form, i.e., a differential π/4-QPSK signal. The digital signal is provided to intermediate frequency (IF) processor 28 which converts the digital signal into an analog signal and modifies the frequency of the analog signal upward to an intermediate frequency. The intermediate frequency signal is provided to radio frequency (RF) processor 30. RF processor 30 further modifies the frequency of the carrier signal upward to the radio frequency desired for transmission. The radio frequency signal is provided to amp/switch chip 32. During transmission, chip 32 amplifies the radio frequency signal (as needed) and provides that amplified signal to an antenna for transmission to base station 14. During reception, a signal received at the antenna is provided to IC 32 which passes the received signal to RF processor 30. RF processor 30 down converts or heterodynes the receive signal to an intermediate frequency signal, preferably the same intermediate frequency used during transmission. The intermediate frequency signal is provided to IF processor 28. IF processor 28 further down converts the frequency of the intermediate frequency signal, preferably a two step or dual down conversion, and generates a digital signal representative of the down converted received signal. The digital signal generated by IF processor 28 is provided to base band processor 26 for conversion into a voice signal. Consider now a transmit operation of portable station

24 in greater detail. A microphone (not shown) provides an analog voice signal to pulse code modulation (PCM) codec 34. Codec 34 converts the analog voice signal into a pulse code modulated signal. Codec 34 can be any known device for converting analog voice signals into PCM signals. The PCM may include VOX processing so that when the user of portable station 24 is not speaking, the PCM signal will indicate as such to the base band processor 26. The PCM signal is provided to base band processor 26. During standby mode for either transmit or receive operations, the PCM will still continue to function and provide signals to the base band processor 26. It is noted that various peripheral devices are utilized in order to enable the transmit operation. In particular, keypad 36, liquid crystal display (LCD) 38 and light emitting diodes (LED) 40 are used to initiate transmission. Keypad 36 is operative through decoder 42 to provide appropriate dialing or keying signals to processor 44. Processor 44 in turn operates LCD 38 through driver 46 and is shown to enable LED 40 directly. Processor 44 in turn interacts directly with base band processor 26. A master oscillator 48 provides a master clock signal to processors 26 and 28. In the preferred embodiment, the frequency of the master clock signal is 19.2 MHz. The master oscillator also operates during standby mode since it used along with other components to track and identify the transmit and receive time slots for portable station 24. During sleep mode, however, this oscillator will not function and only the low frequency oscillator 31 will be used to determine when the next boundary will occur for a possible paging signal from the base station 14.

Processor 26 converts the PCM signal to a digital signal having a repetition rate of approximately 1.152 MHz, and interpolates the digital signal at an effective sampling rate of 9.6 MHz. The output of base band processor 26 is a series of digital samples representative of a modulated carrier signal having a frequency of 10.752 MHz. The samples are provided to IF processor 28. The base band processor 26 also provides the control functions for the various power usage reduction methods of the present invention including sleep and standby mode.

IF processor 28 converts the samples into an analog IF carrier in an internal digital-to-analog converter and thereafter filters the analog signal through bandpass filter 50. The IF processor 28 also includes a reference divider 101 which provides a reference timing signal to the base band processor 26 and the keyboard processor 44. This reference timing signal is used to provide clock signals for the base band processor 26 and the keyboard processor 44. The filtered signal is provided back to IF processor 28 whereupon it is mixed with a local oscillator signal having a frequency of 259.2 MHz. The resulting signal, having a frequency of 248.448 MHz is thereafter passed through bandpass filter 52.

The output of band pass 52 is provided to RF processor 30 whereupon it is again mixed with a signal having a particular frequency. The object of this final mixing operation is to fix the frequency of the signal to be transmitted at the frequency of a desired channel. The reference signal which is utilized in this final mixing step is generated by synthesizer 54. It will be recalled that this reference frequency is a multiple of 300 kHz. It is noted that 300 kHz is chosen in relation to the channel spacing requirements. After this final mixing stage, a signal having a frequency in the range between 1,895 MHz to 1,918 MHz, is passed through bandpass filter 56 to amplifier/switch IC 32. During a transmit operation, IC 32 passes the signal received from filter 56 through an internal amplifier, the output of which is connected to filter 58. In the preferred embodiment of the invention, the base band processor 26 controls the level of amplification of the signal. The base band processor 26, during a receive operation, receives information from the base station 14 which indicates the strength of quality of the signal transmitted from portable station 24 to the base station 14. The base band processor 26 then controls the level of amplification or strength of the signal produced by the amplifier/switch IC 32 via the level control. After passing through filter 58, the signal to be transmitted is provided back to chip 32 where it is connected to antenna 60 for transmission. It is noted that the switching of processors 28, 30 and 32 between transmit and receive operations is controlled by a T/R control signal generated by processor 26. In the preferred embodiment of the invention, the power usage of components in the processors 28, 30, and 32 specifically used for either transmit or receive operations is reduced based on the T/R control signal. The base band processor 26 generates the T/R control signal as a function of the respective time slots for portable station 24.

Consider now the structure of portable station 24 during a receive operation, i.e., when the receive time slot corresponding to portable station 24 is being copied or processed. Base band processor 26 generates an appropriate receive control signal which is applied to processors 28, 30 and 32 including awaking the processors from standby mode to receive mode, those components in the processors specific for transmit operations may remain in standby mode in the preferred embodiment of the invention. Upon receipt of this signal, IC 32 switches antenna 60 into a receive path, whereupon the signal from antenna 60 is passed through filter 62 back into IC 32 or directly to level network 128 by the switch 125 and provided to bandpass filter 56.

The output of band pass filter 56 is provided to RF processor 30. The receive signal is mixed in RF processor 30 with a signal generated by synthesizer 54 so that the desired carrier frequency is selected as a result of the heterodyne operation. The frequency of the signal generated by synthesizer 54 is such that the selected carrier is output from RF processor 30 at a frequency of approximately 248.448 MHz. The selected carrier output from RF processor 30 is passed through bandpass filter 52 and provided to IF processor 28.

IF processor 28, through a mixing operation, reduces the frequency of the selected carrier to approximately 10.75 MHz. This signal is thereafter passed through bandpass filter 50. In an especially preferred embodiment, a separate bandpass filter is utilized for filtering the receive signal at this point. The selected carrier signal is thereafter subjected to a further mixing operation in order to reduce the carrier frequency to 1.15 MHz. The resulting 1.15 MHz signal is passed through bandpass filter 64 and back to IF processor 28. At this point, IF processor 28, preferably via a limiting-interpolation operation, generates a digital signal representative of the selected carrier signal which is still in an analog form. The digital signal generated by IF processor 28 is provided to base band processor 26 whereupon it is demodulated and converted into a PCM signal and provided to codec 34. Codec 34 thereafter converts the PCM signal into an analog signal which is provided to a speaker (not shown) for reproduction.

Referring now to Fig. 3, a description of the base station structure will be provided. It is noted initially that the structure of base station 14 is largely identical to that disclosed in Fig. 2, except for devices utilized in relation to base band processor 26. Consequently, only the differences are shown in Fig. 3. In addition, although the power usage reduction methods are described herein only in relation to portable station 24, the methods could also be implemented in the base station 14 to reduce its power usage, for example, from a local utility providing the power for the base station 14. In the embodiment described herein, base band processor 28 as used in base station 14, is not associated with any microphone or speaker. Clearly, such a modification could be made upon reviewing the disclosure of Fig. 2. Accordingly, the invention includes such a modification within its scope.

As shown in Fig. 3, base band processor 28 is again connected to a PCM codec 34. PCM codec 34 is in turn connected to an input/output device 66 which in turn is connected to public telecommunications network 16. It will be recalled that base band processor 28 in portable station 24 converted the signal provided by codec 34 into a series of digital samples. The first step in that conversion, for both portable station 24 and base station 14, is the processing of the PCM signal in an adaptive pulse code modulator (ADPCM) 68. The output of input/output device 66 is also connected to a PCM codec 70 which in turn is connected to a further ADPCM 72 operates in a manner virtually identical to ADPCM 68. The output of device 72 is provided to base band processor 26 through input/output portion 74. By providing two ADPCM units, base station 14 can handle two portable stations simultaneously. In other words, base station 14 can handle two separate incoming phone calls from network 16. The signals generated by ADPCM 68 and 72 are stored in buffer 76 for further processing by processor 26.

Since the differences between the portable stations and the base stations have been described in relation to Fig. 3, descriptions hereinafter will not be directed to any one type of station. Fig. 4 generally discloses the internal operation of base band processor 26. Processor 26 is shown to include a central bus 80 which interconnects all of the various components of processor 26. Processor 82 is connected to bus 80 and is primarily responsible for adaptive pulse code modulation or adaptive pulse code demodulation, depending on whether a transmit or receive operation is being carried on, i.e., whether the user of the portable station is speaking, for example using VOX. Programming for processor 26 is contained in read-only memory 84. An interface processor 86 is provided for interfacing processor 26 with the various peripheral devices, i.e., keypad 36, LCD 38 and LED 40. A support device 88 is provided for the transmission and reception of various control signals such as the T/R, standby, sleep, RF sleep, and level control signals. As will be described in relation to Fig. 8, support device 88 receives indications of temperature and voltage, which signals are operated upon by received signal strength indicator (RSSI) 89 in order to maintain an accurate estimate of signal strength and correspondingly determine whether to amplify or attenuate the received signal in the amplifier/switch IC 32. The support device 88 also receives a signal from the low frequency oscillator 31 indicating the cycles of the low frequency oscillator.

The support device 88 may count these cycles or a counter (not shown) may be used to count these signals during a monitor operation to determine when to place the other ICs in sleep mode and when to awaken the ICs to listen for a paging signal from the base station 14. In the preferred embodiment of the invention, the low frequency oscillator operates at 32,768 Hertz, so that it produces 32,768 cycles or counts every second. The counter or support device 88 may count to some first predetermined number less than 32,768 and then awaken the ICs to listen for the paging signal. In the preferred embodiment of the invention, the support device 88 first awakens the IF processor 28 and synthesizer 54 when the count is equal to a first predetermined number. Then the support device 88 awakens the RF processor using the RF sleep signal when the count is equal to second predetermined number where the second predetermined number is greater than the first predetermined number. This embodiment takes in account the various required settling times of the components to prepare to listen and receive a possible paging signal from the base station 14.

In a further preferred embodiment of the invention, after a third predetermined number greater than 32,768 counts, the support device places the awakened ICs back into sleep mode if a paging signal was not detected. This process repeats until a paging signal is received, or a user of the portable station initiates a call. Note that the base station may also have a sleep mode where it detects calls from the network 16 or paging signals from portable station 24 at only certain predetermined intervals. A modem 90 is provided for the demodulation of received signals and for the modulation of signals to be transmitted. To this end, modem 90 includes a modulator 92 and a demodulator 94. Modem 90 controls both the provision of signals to IF processor 28 and the reception of signals from processor 28. In the preferred embodiment of the invention, during standby operations, only the modulator 92 portion of the modem will draw power during the transmit time slot and only the demodulator 94 portion of the modem will draw power during the receive time slot. It will be recalled that the digital signal received by demodulator 94 is representative of the analog signal received at antenna 60.

Modulator 92 is connected to bus 80 and is responsible for producing a series of digital samples of a modulated carrier having a frequency of 10.752 MHz, referred to previously. The samples generated by modulator 92 are output from modem 90 to IF processor 28. Modem 90 is controlled in a fashion that digital samples generated by modulator 92 are only transmitted during prescribed time periods, i.e., during the corresponding transmit time slot for portable station 24. During all other time periods, modem 90 prevents the transmission of digital samples to processor 28.

Referring now to Fig. 5, the general construction of IF processor 28 will be described. The IF processor 28 receives control signals from the base band processor 26 including the sleep, standby, and T/R signal. In the preferred embodiment of the invention, if the IF processor 28 receives the sleep signal, all the components of the IF processor 28 are inactive or have reduced power usage. In another preferred embodiment of the invention, all the components of the IF processor 28 are inactive during sleep mode except the reference divider 101. As explained above, the reference divider provides a reference timing signal which is used by the base band processor 26 and the keyboard processor 44. In the preferred embodiment of the invention, the reference divider provides a 9.6 MHz clock signal. In the preferred embodiment of the invention, this mode is invoked when the user of the portable station 24 is entering information on the keypad 36 of the cordless phone for a purpose other than initiating a call such as programming numbers in a memory device (not shown) of the portable station 24.

If the IF processor 28 is placed in standby mode, components of the processor are made inactive and then only certain components are made active depending on the T/R signal as certain components are only used for transmit or receive operations but not both. These components are described in more detail below. In detail, the series of digital samples generated by modulator 92 is provided by modem 90 to digital to analog converter 96. Converter 96 converts the series of digital samples into an analog signal having a carrier frequency of approximately 10.752 MHz and modulated in accordance with information provided by modulator 92. In the preferred embodiment of the invention, during standby operations, converter 96 is only active during the corresponding transmit time slot for portable station 24. During a transmit operation, this analog signal is passed through band pass filter 50 and provided to mixer 98. As a consequence, in the preferred embodiment of the invention, during standby operations mixer 98 is also only active during the corresponding transmit time slot for portable station 24 The 10.752 MHz signal is mixed with a signal generated by local oscillator 100. The frequency of the signal generated by oscillator 100 in the preferred embodiment is approximately 259.2 MHz. Since the transmit operation is occurring, the T/R signal generated by base band processor 26 is indicating transmit. Accordingly, switch 102 is switched to transmit the output of mixer 98 to band pass filter 52. In the preferred embodiment of the invention, the switch 102 and local oscillator 100 are in standby mode except during the transmit and receive time slots for portable station 24. During a receive operation, the analog signal passing through filter 52 is provided to switch 102. The T/R signal will be indicating receive during a receive operation. Accordingly, switch 102 will provide the signal received from filter 52 to mixer 104. In the preferred embodiment of the invention, during standby operations, mixer 104 is only active during the corresponding receive time slot for portable station 24. Mixer 104 mixes the receive signal with the same 259.2 MHz signal generated by oscillator 100 producing an analog signal having a frequency of approximately 10.75 MHz. As indicated previously, this 10.75 MHz signal can either be passed through band pass filter 50 or preferably through another band pass filter (not shown) .

After filtering, the 10.75 MHz signal is provided to mixer 106, where it is mixed with a 9.6 MHz signal resulting in an output signal of approximately 1.15 MHz. The 1.15 MHz signal is provided to filter 64 and to level detector 107. Level detector 107 senses the received signal strength and generates a received signal strength indication ("RSSI") signal which is used to determine whether to amplify or attenuate the received signal in the amplifier/switch 32. This indication signal is provided to base band processor 26. A more detailed description of the use of this RSSI signal is described in relation to Fig. 7. Generally, the level indication signal will be used to control either the amplification or attenuation of the received signal and thus reduce the power usage of the amplifier/switch IC 32 when appropriate. In the preferred embodiment of the invention, the mixer 106 and level detector 107 are in standby mode except during the receive time slot for portable station 24.

The output of filter 64 is provided to a limiter - sampler 108. The limiter - sampler generates a digital signal representative of the information contained in the 1.15 MHz signal received from filter 64. As a consequence, in the preferred embodiment of the invention, during standby operations, the limiter - sampler 108 is only active during the corresponding receive time slot for portable station 24. The digital signal generated by limiter - sampler 108 is provided to demodulator 94 in base band processor 26. An analog to digital and a digital to analog converter 110 is also provided in IC 28. As will be appreciated in relation to Fig. 8, converter 110 operates to provide environment information to base band processor 26 and also operates to generate control signals for oscillator 48.

Referring now to Fig. 6, the structure of RF processor 30 will be discussed in greater detail. The RF processor 30 receives control signals from the base band processor 26 including the RF sleep, standby, and T/R signal. In the preferred embodiment of the invention, if the RF processor 30 receives the sleep signal, all the components of the RF processor 30 are inactive or have reduced power usage. As noted above, in the preferred embodiment of the invention, the RF processor 30 receives its own sleep signal which generated after the awaken sleep signal is generated for the ICs which may be placed in sleep mode.

If the RF processor 30 is placed in standby mode, components of the processor are made inactive and then only certain components are made active depending on the T/R signal as certain components are only used for transmit or receive operations but not both.

In particular, during a transmit operation, analog signals passing through filter 52 are provided to switch 112. Switch 112 in turn provides the analog signal to mixer 114 where it is mixed with a signal generated by synthesizer 54. Then the signal is amplified in amplifier 115 and passed to the switch 116. As a consequence, in the preferred embodiment of the invention, during standby operations, the mixer 114 and amplifier 115 are only active during the corresponding transmit time slot for portable station 24. It will be recalled that the frequency of signals generated by synthesizer 54 are fixed so that the output of mixer 114 is at a desired carrier frequency in the range of frequencies between 1,895 MHz and 1,918 MHz. The output of mixer 114 is provided to amplifier 115 and then to switch 116 which during the transmit mode is switched to provide this analog signal to filter 56. The placement of mixer 114 and amplifier 115 between switch 112 and 116 defines a transmit path. Similar to mixer 104, mixer 114 is preferably a single sideband up converter which provides image rejection. Such image rejection significantly reduces the power requirements of any signal amplification provided by IC 30. In other words, providing image rejection reduces by approximately four times the maximum signal level to be amplified. The power requirements of amplifier 122 (Fig. 7) are thus minimized by providing image rejection in mixer 114.

During a receive operation, the signal present on antenna 60 is provided through filter 56 to switch 116. Switch

116 in the receive mode is switched to provide the receive signal to mixer 118 where it is mixed with a signal generated by synthesizer 54. In the embodiment shown in Fig. 6, the signal provided by synthesizer 54 to mixer 118 is the same frequency as that provided to mixer 114. The heterodyne technique used in conjunction with mixer 118 serves to select one of the carrier signals received in antenna 60. The selected carrier signal is provided to switch 112 which in turn passes the selected signal to filter 52. In the preferred embodiment of the invention, during standby operations, the mixer 118 is only active during the corresponding transmit time slot for portable station 24 and the switch 116 is only active during the corresponding transmit and receive time slots for portable station 24. The synthesizer 54 receives the sleep signal from the base band processor 26 and thus it is inactive during monitoring modes except when made active about the boundary of the one second interval to determine whether a paging signal has been generated by the base station 14.

The signal provided to mixer 118 is also provided to level detector 119. Detector 119 senses the strength of the received signal and generates the RSSI signal. This RSSI signal is provided to base band processor 26 and as noted above is used in conjunction with other signals to determine whether to amplify or attenuate the received signal in the amplifier/switch IC 32. A more detailed description of the use of this indication signal is described in relation to Fig. 7. Generally, the level indication signal, similar to that generated by detector 107, will be used to control either the amplification or attenuation of the received signal. Referring now to Fig. 7, the operation of IC 32 will be described in greater detail. The IC 32 receives a level control signal from the base band processor 26 which indicates whether the level of amplification necessary for the transmit signal as indicated by the quality signal sent by the base station 14 and received by portable station 24. During a transmit operation, a signal is received from filter 56, the frequency of which is at the selected carrier frequency. The signal is provided to switch 120 which in turn provides the carrier signal to amplifier 122. Amplifier 122 provides the necessary power amplification such that when the carrier signal is provided to antenna 60, the signal will be received by a portable station or base station as the case may be. In the preferred embodiment of the invention, the level control is provided to the amplifier 122 and controls the level of amplification of the carrier signal as a function of the quality of previously transmitted signals to the base station 14. By varying the amplification level as a function of the quality of signal (which is a function of the location of portable station 24 relative to the base station 14) , the power usage of the amplifier can be reduced.

The output of amplifier 122 is provided to filter 58. The output of filter 58 is provided to switch 124. During a transmit mode, switch 124 is switched to provide the output of filter 58 to antenna 60. IC 32 is also shown to include a negative voltage generator 126. Generator 126 converts the local oscillator signal provided by IC 28 into a negative voltage for use in switch 120, amplifier 122 and switch 124. It will be noted that elements 120-124 are preferably implemented utilizing a number of field effect transistors (FETs) . The use of a negative voltage significantly reduces power consumption in such devices. Consequently, more precise operation of these elements can be achieved. Moreover, since the portable stations are battery powered, an independent source of negative voltage is unavailable.

During a receive mode, the signal received by antenna 60 is provided by switch 124 to switch 125. Switch 125 directs the received signal either directly to the level network 128 or the level network 128 via the filter 62. If switch 125 directs the signal to the filter 62, then the output of filter 62 is provided to level network 128 where the received signal is modified. Preferably, the received signal is either amplified or attenuated. The output of network 128 is provided to filter 56. The switch 125 is controlled by the processor 26. If the received signal is to be attenuated by the level network 128, then the signal is switched directly to the level network 128 bypassing the filter 62, otherwise the received signal is switched to the filter 62.

In the embodiment depicted in Fig. 7, the received signal applied to network 128 is either amplified in a low noise amplifier which provides approximately 13dB of gain, or attenuated by approximately -4dB in a first attenuator or attenuated by approximately -28dB in a second attenuator. The received signal is processed by one of these components depending on the orientation of a switch mechanism. The switch is controlled by a control signal generated by processor 26. Processor 26 will switch between the various components until level indicator 107 indicates that the received signal is at some desired level or within some desired range. By providing this switching network, saturation caused by the portable station getting too close to the base station is avoided and in addition, the power usage of the amplifier 128 is reduced.

Referring now to Fig. 8, a more detailed embodiment of IF chip 28 is depicted. The functions of the components of the IF IC 28 during standby and sleep modes were described above. It is noted, however, that the controller 132 of the IF processor 28 receives and processes the standby and sleep signals from the base band processor 26. It is further noted that the controller 132 may reduce the power usage of all the components of the IF processor 28 in sleep mode except for the reference divider 101 in a particular sleep mode described above where, for example, the user of the portable station 24 is programming numbers in a memory device (not shown) of the portable station 24.

Chip 28 is shown to include a data bus 130. It is noted that data bus 130 is shared for both transmitting information during a transmit operation, writing to ADC/DAC 110 and for providing environmental data to base band processor 26. Consider first the operation of processor 28 during a transmit operation.

The transmit/receive (T/R) signal is provided to controller 132. Controller 132 operates, among other things, to switch the signal up/down converter 134 into the up conversion mode. In accordance with a transmission operation, a series of digital samples are provided by processor 26 to bus 130 whereupon such samples are converted by digital to analog converter 136 into an analog signal having a frequency of approximately 10.752 MHz, which signal is provided to filter 50. It will be recalled that should processor 26 decide to modify the level of the signal to be transmitted, processor 26 can modify the conversion, i.e., increase or decrease the amplitude of the analog output.

The signal passing from filter 50 is provided to up/down converter 134 which in the preferred embodiment can be a single or double balanced mixer. As previously described in relation to Fig. 5, a master oscillator signal is provided to a local oscillator 136 (previously oscillator 100) which provides the required frequency signal to converter 134. It will be recalled that the frequency of the signal generated by oscillator 136 is preferably 259.2 MHz, i.e., an integer multiple (27) of 9.6 MHz. The output of up/down converter during the transmit mode is provided to filter 52.

During a receive mode of operation, the output of filter 52 is provided to up/down converter 134 whereupon the signal is converted down to a frequency of approximately 10.75 MHz. Although this signal can be passed through filter 50, it is preferable to pass this signal through a separate 10.75 MHz band pass filter. The output of the separate band pass filter is provided to mixer 138. Mixer 138 mixes the receive signal with the 9.6 MHz signal received from synthesizer 48. The output of mixer 138 is a signal having a frequency of approximately 1.15 MHz which is provided to band pass filter 64. The output of mixer 138 is also provided to level detector 107, which detects the strength of the received signal. Detector 107 generates an indication signal which is converted to digital form and applied to shared bus 130.

The output of filter 64 is provided to limiter - sampler 140. As was indicated previously, the limiter - sampler 140 (previously 108) generates a signal representative of the analog signal received from filter 64 from which signal strength can be determined. The signal generated by limiter - sampler 140 is provided to converter 144 for conversion into digital form and applied to bus 130 for provision to the received signal strength indicator (RSSI) 89 in processor 26.

Temperature and voltage sensing devices 146 and 148, respectively, provide signals which are indicative of the operating environment of processor 28. In particular, the temperature device provides an indication of the temperature of the chip. Voltage sensor 148 monitors the output voltage of battery 149. It will be recalled that ICs 26, 28, 30 and 32 are implemented in portable station 24 in connection with battery power. Battery 149 provides such power. As the voltage output of battery 149 rises and falls (assuming a re¬ chargeable battery is utilized) , various transmit and receive signal levels will be effected. Consequently, the battery voltage is monitored. The output of devices 146 and 148 are also provided to converter 144 which in turn provides a digital signal representative of the temperature and voltage on shared data bus 130. The temperature and voltage information are utilized by processor 26 in order to regulate the frequency being generated by master oscillator 48. To this end, processor 26 generates a control signal in support portion 88 (Fig. 4) which is provided to shared data bus 130. This control signal is converted by digital to analog controller 150 and provided to master oscillator 48. As discussed above, this environmental information is used to determine whether to attenuate or amplify the received signal in the amplifier/switch IC 32.

Processor 26 also uses the temperature and voltage information in conjunction with the quality signal information received from the base station 12 to adjust the level of the signal being transmitted. In this regard, one embodiment of processor 26 can include a look-up table of temperature and voltage values with corresponding gain modification information. No special method for generating such a table is necessary. It has been found that the generation of this table can be accomplished empirically. In the preferred embodiment, the values which would be stored in such a table are analyzed and an equation is developed, using known curve fitting techniques, from which gain modification information can be determined dynamically.

While the invention has been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that modifications and variations may be made without departing from the principles of the invention as described hereinabove and set forth in the following claims.

Claims

CLAIMS What is Claimed is:

1. A method of reducing power usage of a cordless phone, said method comprising the steps of: a) reducing power usage of at least one component of said cordless phone; b) monitoring cycles produced by a low power, low frequency oscillator of said cordless phone; c) determining whether the number of cycles produced by the frequency oscillator is equal to a first predetermined number; and d) increasing power usage of at least one component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said first predetermined number.

2. A method according to claim 1, further comprising the steps of: e) determining whether the number of cycles produced by the frequency oscillator is equal to a second predetermined number where said second predetermined number is greater than said first predetermined number; and f) increasing power usage of at least one other component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said second predetermined number.

3. A method according to claim 2, wherein step d) comprises: increasing power usage of at least one signal receiving component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said first predetermined number.

4. A method according to claim 3, further comprising the steps of: g) determining whether the number of cycles produced by said frequency oscillator is equal to a third predetermined number; h) detecting via signal receiving components of said cordless phone whether a predetermined signal has been received via an antenna of said cordless phone; and i) repeating steps a) to h) as a function of whether the number of cycles produced by the frequency oscillator is equal to said third predetermined number and whether signal receiving components of said cordless phone have detected said predetermined signal.

5. A method of reducing power usage of a cordless phone during a call where said cordless phone sends signals in a time division duplex format having a plurality of transmit time slots, said method comprising the steps of: a) determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and b) reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

6. A method of reducing power usage of a cordless phone during a call where said cordless phone receives signals in a time division duplex format having a plurality of receive time slots, said method comprising the steps of: a) determining whether a signal is to be copied from a particular receive time slot by said cordless phone; and b) reducing power usage of components of said cordless phone until the signal is to be copied from the particular receive time slot by said cordless phone.

7. A method according to claim 6 where said cordless phone receives and sends signals in a time division duplex format having a plurality of transmit time slots and a plurality of receive time slots, said method further comprising the steps of: c) determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and d) reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

8. A method according to claim 7, where in step b) the components include signal receiving components of said cordless phone and where in step d) the components include signal transmitting components of said cordless phone.

9. A method of reducing power usage of a cordless phone during a call where said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, said method comprising the steps of: a) determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and b) reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on the determination performed in immediately preceding step a) .

10. A method of reducing power usage of a cordless phone during a call, said method comprising the steps of: a) receiving a signal; b) determining, as a function of the received signal, strength of the received signal; c) determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; and d) adjusting the strength of the received signal based on the determination of whether the received signal is acceptable.

11. A method according to 10, wherein said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, and said method further comprising the steps of: e) determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and f) reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on the determination performed in immediately preceding step e) .

12. A method according to claim 1 where said cordless phone receives and sends signals in a time division duplex format having a plurality of transmit time slots and a plurality of receive time slots and said method further comprising the steps of: e) determining whether a signal is to be copied from a particular receive time slot by said cordless phone; f) reducing power usage of components of said cordless phone until the signal is to be copied from the particular receive time slot by said cordless phone; g) determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and h) reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

13. A method according to 1, wherein said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone and said method further comprising the steps of: e) receiving a signal; f) determining, as a function of the received signal, strength of the received signal; g) determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; h) adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; i) determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and j) reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on the determination performed in immediately preceding step i) .

14. A method according to claim 4 where said cordless phone receives and sends signals in a time division duplex format having a plurality of transmit time slots and a plurality of receive time slots and said method further comprising the steps of: j) determining whether a signal is to be copied from a particular receive time slot by said cordless phone; k) reducing power usage of components of said cordless phone until the signal is to be copied from the particular receive time slot by said cordless phone;

1) determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and m) reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

15. A method according to 4, wherein said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone and said method further comprising the steps of: j) receiving a signal; k) determining, as a function of the received signal, strength of the received signal;

1) determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; m) adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; n) determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and o) reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on the determination performed in immediately preceding step n) .

16. A method according to 7, wherein said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone and said method further comprising the steps of: e) receiving a signal; f) determining, as a function of the received signal, strength of the received signal; g) determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; h) adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; i) determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and j) reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on the determination performed in immediately preceding step i) .

17. A method according to 14, wherein said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone and said method further comprising the steps of: n) receiving a signal; o) determining, as a function of the received signal, strength of the received signal; p) determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; q) adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; r) determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and s) reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on the determination performed in immediately preceding step r) .

18. A cordless phone having reduced power usage, said cordless phone comprising: reducing means for reducing power usage of at least one component of said cordless phone; means for monitoring cycles produced by a low power, low frequency oscillator of said cordless phone; means for determining whether the number of cycles produced by the frequency oscillator is equal to a first predetermined number; and increasing means for increasing power usage of at least one component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said first predetermined number.

19. A method according to claim 18, further comprising: means for determining whether the number of cycles produced by the frequency oscillator is equal to a second predetermined number where said second predetermined number is greater than said first predetermined number; and means for increasing power usage of at least one other component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said second predetermined number.

20. A cordless phone according to claim 19, wherein said increasing means comprises: means for increasing power usage of at least one signal receiving component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said predetermined number.

21. A cordless phone according to claim 20, further comprising: means for determining whether the number of cycles produced by said frequency oscillator is equal to a third predetermined number; means for detecting via signal receiving components whether a predetermined signal has been received via an antenna of said cordless phone; and means for reducing the power usage of at least one component of said cordless phone, monitoring the cycles produced by the low power, low frequency oscillator of said cordless phone, determining whether the number of cycles produced by the frequency oscillator is equal to said first predetermined number, increasing the power usage of at least one signal receiving component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said first predetermined number, determining whether the number of cycles produced by the frequency oscillator is equal to said second predetermined number, increasing the power usage of at least one signal receiving component of said cordless phone as a function of whether the number of cycles produced by said frequency oscillator is equal to said second predetermined number, determining whether the number of cycles produced by said frequency oscillator is equal to said third predetermined number and detecting via signal receiving components whether said predetermined signal has been received via said antenna of said cordless phone as a function of whether the number of cycles produced by the frequency oscillator is equal to said third predetermined number and whether said signal receiving components of said cordless phone have detected said predetermined signal.

22. A cordless phone having reduced power usage, where, during a call, said cordless phone sends signals in a time division duplex format having a plurality of transmit time slots, said cordless phone comprising: means for determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and means for reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

23. A cordless phone having reduced power usage, where, during a call, said cordless phone receives signals in a time division duplex format having a plurality of receive time slots, said cordless phone comprising: means for determining whether a signal is to be copied from a particular receive time slot by said cordless phone; and receive reducing means for reducing power usage of components of said cordless phone until the signal is to be copied from the particular receive time slot by said cordless phone.

24. A cordless phone according to claim 23 where said cordless phone receives and sends signals in a time division duplex format having a plurality of transmit time slots and a plurality of receive time slots, said cordless phone further comprising: means for determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and transmit reducing means for reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

25. A cordless phone according to claim 24, where in the receive reducing means the components include signal receiving components of said cordless phone and where in the transmit reducing means the components include signal transmitting components of said cordless phone.

26. A cordless phone having reduced power, where, during a call, said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, said cordless phone comprising: transmission reduction determining means for determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and means for reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on determinations by said transmission reduction determining means.

27. A cordless phone having reduced power usage during a call, said cordless phone comprising: means for receiving a signal; means for determining, as a function of the received signal, strength of the received signal; means for determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; and means for adjusting the strength of the received signal based on the determination of whether the received signal is acceptable.

28. A cordless phone according to 27, where said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, said cordless phone further comprising: transmission reduction determining means for determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and means for reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on determinations by said transmission reduction determining means.

29. A cordless phone according to claim 18 where said cordless phone receives and sends signals in a time division duplex format having a plurality of transmit time slots and a plurality of receive time slots, said cordless phone further comprising: means for determining whether a signal is to be copied from a particular receive time slot by said cordless phone; receive reducing means for reducing power usage of components of said cordless phone until the signal is to be copied from the particular receive time slot by said cordless phone; means for determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and transmit reducing means for reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

30. A cordless phone according to 18, where said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, said cordless phone further comprising: means for receiving a signal; means for determining, as a function of the received signal, strength of the received signal; means for determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; means for adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; transmission reduction determining means for determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and means for reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on determinations by said transmission reduction determining means.

31. A cordless phone according to claim 21 where said cordless phone receives and sends signals in a time division duplex format having a plurality of transmit time slots and a plurality of receive time slots, said cordless phone further comprising: means for determining whether a signal is to be copied from a particular receive time slot by said cordless phone; receive reducing means for reducing power usage of components of said cordless phone until the signal is to be copied from the particular receive time slot by said cordless phone; means for determining whether a signal is to be inserted in a particular transmit time slot by said cordless phone; and transmit reducing means for reducing power usage of components of said cordless phone until the signal is to be inserted in the particular transmit time slot by said cordless phone.

32. A cordless phone according to 21, where said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, said cordless phone further comprising: means for receiving a signal; means for determining, as a function of the received signal, strength of the received signal; means for determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; means for adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; transmission reduction determining means for determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and means for reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on determinations by said transmission reduction determining means.

33. A cordless phone according to 24, where said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, said cordless phone further comprising: means for receiving a signal; means for determining, as a function of the received signal, strength of the received signal; means for determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; means for adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; transmission reduction determining means for determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and means for reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on determinations by said transmission reduction determining means.

34. A cordless phone according to 31, where said cordless phone receives signals which indicate quality of signals transmitted by said cordless phone, said cordless phone further comprising: means for receiving a signal; means for determining, as a function of the received signal, strength of the received signal; means for determining, as a function of determined strength of the received signal, whether the strength of received signal is acceptable; means for adjusting the strength of the received signal based on the determination of whether the received signal is acceptable; transmission reduction determining means for determining, as a function of the received signals which indicate the quality of signals transmitted by said cordless phone, whether strength of signals transmitted from said cordless phone can be reduced; and means for reducing power usage of components of said cordless phone to reduce the strength of signals transmitted from said cordless phone based on determinations by said transmission reduction determining means.