GB2267167A

GB2267167A - Pager power-saving

Info

Publication number: GB2267167A
Application number: GB9307063A
Authority: GB
Inventors: Kam-Fu Wong
Original assignee: Star Paging Communications Equipment Manufacturing Ltd
Current assignee: Star Paging Communications Equipment Manufacturing Ltd
Priority date: 1992-05-21
Filing date: 1993-04-05
Publication date: 1993-11-24
Also published as: CN1033063C; GB9307063D0; CN1079086A

Abstract

A method of power-saving operation for a pager including remote-controllable power saving in which the pager receives from paging stations a message incorporating a power saving command, shuts off power supply to the RF receiver according to the command, maintains limited functions in the CPU, and resumes normal operation at a specified time, so that battery power can be saved. In another method, the pager temporarily stops receiving on daily scheduled periods keyed into the pager, subject to an entered password being correct. In another method for divided batch power saving, the pager receives a message in a format, different from the regular POCSAG power saving format of one reception every batch, but rather using one reception in a specified batch number and in a specified frame number.

Description

SPECIFICATION METHOD OF POWER-SAVING OPERATION FOR PAGER AND PAGER ADAPTED TO METHOD OF POWER-SAVING OPERATION Technical field This invention relates in general to a pager or an electronic product equipped with a pager. The invention relates in particular to a method of power saving operation (MPSO) for pager and a pager adapted to this invented method.

Background of the invention A pager may have a configuration as shown in Fig. 1, comprising an antenna, RF receiver, decoder, CPU, LCD display screen, address code memory, low battery detector, clock, and I/O devices like loundspeaker, vibrator, pilot lamps, display lighting, photosensor and control keys.

Of the many control functions of the pager, "power-saving operation'1 is considered as comparatively important in the sense that this function many directly affect the pager's reception performance. Becuase the pager must be powered-on 24 hours, or placed in a normally "ON" state, in order to receive calling signal from time to time. Since electrical power is supplied by a 1.5V alkaline battery (of approximately 800 mAH to 1200 mAH in capacity), a circuit without a power-saving function will quickly use up the battery power. Therefore a pager must incorporate this function and, its instruction booklet must inform the user how long the pager can continuously be used under certain test conditions.

At the present, pager of an ordinary kind has certain power saving functions. Because a pager's power-saving operation often associates closely with the coding format adopted for transmitting and receiving signals, description of a pager here begins with description of coding formats. Although coding formats and frequencies adopted for pages vary from country to country, POCSAG (Post Office Code Standardisation Advisory Group) code has widely been accepted for international applications, including application in China. As shown in Fig. 2, a paging signal consists of a prearnble signal, followed by plurality of batch signals.Each batch is preceded by a synchronization codeword, that is, each batch consists of a sync code (SC) and 8 frames (numberes 0-7), and a frame consists of two codewords, or, each batch consists of 17 codewords in total. The 8 frames in a batch are ordinally named the zeroth frame through the seventh frame. Correspondingly the pagers are grouped by 8's, each frame relates to a group. The address code has 7 digits of a total 21 bits. The 32-bit address codeword, contains 1 address identification bit, 18 address code data bits, 2 functions bits, 10 redundant check bits, and in addition 1 even parity bit. These are combined into one address codeword in transmission. The last 3 bits are for identifying to which group, of the 8 groups, that the address is related.The pager checks only the address message within its own frame, to see if the address in the message conforms to the address of the pager. If the two addresses do conform, then the message codewords subsequent to the address codeword will be accepted. The message codewords can be of any length and can be allowed to extend over to the next batch (the sync code of this next batch not being omitted). Paging messages may end with either an idle code or next address code.

Owing to the pager not wanting the messages from whole batch, the pager's messages are contained in its related frame only, and are accepted after address checking. Therefore the battery of the pager need not support the RF receiver at all times, but a small portion of the power is required to support the basic task for the CPU. This is the power-saving operation adapted to a POCSAG paging format, and is implemented in the process below.

As the pager receives a preamble signal, the RF receiver begins and maintains its electrical connection with the battery, and cuts off when a sync code for the first batch is received. Thereafter the connection is made-again when the related frames appear. (In Fig.

2, for example, said pagers relates to frame 3). At this time the decoder checks if the received message is coincident with the pager's address. If not, then after a very short period of time, power supply automatically cuts off. The connection is not made until a sync code of the next batch appears, then the connection makes. The power supply will be cut-off again on receipt of another sync code. If the decoder sees an identity of the address in a received message with that of said pager, indicating some messages are being sent to said pager, then the power connection makes again till the end of the message transmission.In this way, intermittent connections with the battery coordinate with the task of the Rf receiver that consumes large amount of electricity, but that is not required to work continuously, and only a small amount of power is needed to maintain the basic operation of CPU, and to guarantee the supervisory and monitory routines. 'Consequently, a preliminary objective of power-saving operation is attained.

With reference to Fig. 2, A and B schematically represent two power supply current curves when the pager employs battery saving operation adapted to POCSAG standard. In the figure, curve A shows the situation when the paging signals contain no address nor messages for a particular pager. Curve B shows the situation when the paging signals contain the pager's address or messages. Before the pager receives a preamble signal from a paging station, the period of battery saving operation T is 1.0625 second. When the RF receiver is powered on (or power-saving being "OFF"), the connection time is theoretically P=62.5ms, or duty cyrcle is 1/17.

In actual practice, P is approximatly 82-106ms (duty cycle being 1113-1/10) in consideration of an additional short delay time for screen display of message after the pager receives a paging signal, during which time the connection with battery is stably kept uninterrupted. After the pager receives a preamble signals, the battery is kept connected on, until a sync codeword of batch 1 is received. Thereafter, the power is off until the group (frame), to which said pager relates, appears then the power is automatically on again, and the decoder will check the identity of the received address with the pager's address (namely, whether the pager has been called).If the two addresses are not identical, then after a period of P, the power is turned off automatically (like in example A of Fig,. 2), until the sync codeword of a second batch appears, then connection is made again. It is seen from the above that after the pager receives a preamble signal, the theoretical power-on time in a batch is 3/17 T, and the actual power-on time is between 1/4 T to 1/3 T. Now see Fig. 3, example B, if the decoder identifies a pager's address in frame 3, it indicates that the pager is called. If the pager finds some messages coming in, battery power will be kept on connected till the messages end.

Power-saving "ON'1 consumes about 50uA (for CPU), whereas power-saving "OFF" consumes 5mA (for RF receiver, decoder CPU, etc.,). Thus said power-saving operation on a pager reduces power consumption considerably and ensures a protracted battery life.

However, the aforesaid ordinary power saving method adapted to regular POCSAG does not turn out to be perfectly ideal. In particular, it can not achieve further power-saving under varied paging environments nor meeting different requirements, so that the limited battery power of a pager can not be further economized and adequately and effectively utilized.

Summary of the invention Consequently, the object of this invention is, based on the ordinary POCSAG power saving method, according to a plurality of actual paging environments and needs, to provide a number of new MPSO for further battery saving, and to provide a pager model adapted to MPSO.

In principles, the present invented MPSO can be summarized as: 1. Remote-contrpllable power saving.

When messages are transmitted from paging station to a pager, the message include a command ordering the pager to make a pause, stopping its reception, that is, the RF receiver disconnects power supply and the CPU enters a state of napping allowing only a limited number of functions to operate. When the specified time is up, the CPU is awakened to restore the regular states of receiving messages.

2. Timing power saving.

Similar to the remote-controllable power saving, the timing power saving aims at intermittent paging operations. The pager is set to power on and off the RF receiver on a daily schedule, so that the pager does not receive any messages at set time periods everyday, until the timing power saving order is relieved.

3. Divided batch power saving.

This is a further improvement over the ordinary POCSAG power-saving operation. It turns on the RF receiver, not only at the appearance of async codeword and of the pager-related frames, but also at the appearance of a predetermined ordinal batch number and frame number after identifying a preamble message. (namely, does. not turn on all pager-related frames, in every batch.) Hence more power is saved.

To carry out the present invented MPSO for pages, and to design a pager adapted to the MPS, the technical solutions include: (1) A method of the first kof the invented power-saving Operation, i.e., remote-controllable power-saving operation, for page, said pager comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard; and operating using standard POCSAG power-saving format; said method comprising the following procedures: a. after the pager receiving a calling signal., the decoder decoding remote-controllable power saving message embedded in the information code, and sending the decoded message to CPU for processing; b. power-saving command processing means in CPU identifying the decoded message as a remote-controllable power saving commend, which includes the instructions for specified starting time and for specified ending time of power saving operations; c. the power-savig command processing means in CPU setting the clock respectively according to the power-saving starting time and the ending time instructions; d. on the arrival of a specified power-saving beginning time as detected on the-clock, power-saving commend executing means of CPU forcing the pager to enter said power-saving operation mode in response to a first timing signal issued'from the clock; e. on the arrival of a specified power-saving ending time as detected on the clock, the power saving executing means of CPU forcing the pager to resume its normal operation mode in response to a second timing signal issued from the clock (2) A method of the second kind of the invented power-saving operation, i.e., timing power-saving operation, for paer, said pager comprising:RF receiver, decoder, CPU, clock, memory, display screen and control keyboard, and operating using standard POCSAG power-saving format; said method comprising the following procedures: a. owner selecting timing power-saving function1 through manipulating the numeric keys and control keys on the control keyboard, and the pager awaiting the input of a personal password; b. owner inputting a predetermined numerical sequence representative of his personal password, through manipulating numeric keys; c. pager verifying the validity of said personal password: d. if password being valid, then pager accepting owner's instructions, that have been input through numeric keys, of a specified daily beginning time and ending time for power saving.

d-l. power-saving command processing means of CPU storing into special storage means in memory, the said instructions of beginning time and ending time for power saving, and setting the clock every day according to the beginning time and ending time; d-2. on the arrival of the power saving beginning time, as specified on the clock, power-saving executing means of CPU forcing the pager to enter said power-saving operation mode in response to a first timing signal issued from the clock; d-3. on the arrival of the battery-saving ending time, as specified by the clock, the CPU forcing the pager to resume normal operation mode in response to a second timing signal issued from the clock;; e. if password being invalid, then pager awaiting a second password input, and repeating said password verifying procedures, until password being entered wrongly for n consecutive times (where n is integer greater than 1) then the pager entering a frozen state.

(3) A method of the third kind of the inveted power-saving operation, i.e., divided batch power-saving operation, for pager, said pager comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard; and operating using standard POCSAG power-saving format, and in the paging message format, the page:c's address and information being specified as in batch m and frame n (n, m is unity or positive integers greater than 1); said method comprising the following procedures: a. after the pager receiving a calling signal, the first sync signal after preamble in the received message signal being identified by divided batch receiving control means of the CPU, and CPU forcing the power supply of the RF receiver being switched off and forcing the pager to enter a state of power-saving operation after the first sync signal being over; b. divided batch receiving execution means of the CPU setting the clock according to the S value, - calculated by the formula S=(m-l)xM+(n-l)xN, in response to the identified first sync signal, where m is the batch number and n is the frame number, both being stored in the. pager;M and N are respectively the times laped in one batch and in one frame according to the paging information format; c. in response to the timing signal issued from the clock at the times indicated by S, the divided batch receiving execution means of the CPU forcing the RF receiver being powered-on, allowing the pager to receive said paging message in frame n, batch m, as being specified; d. after said paging messages end, the divided batch receiving control means of CPU switching off the supply to RF receiver and forcing the pager to enter the state of power saving operation again.

(4) A pager adapted to the method of invented remote-controllable power saving operation, comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard, characterized in said CPU further comprising: power-saving command processing means, for identifying a decoded remote-controllable power saving command from decoder, (said command including instructions of specified beginning time and ending time of power- saving operation), storing data of said command into memory, and setting the internal clock according to said beginning time and ending time; and power-saving command executing means, for forcing the pager into power saving mode and temporarily stopping the reception function of RF receiver, in response to the first timing signal issued by the clock corresponding to said beginning time; and for restoring the pager back to normal operation and resuming the reception function of RF receiver, in response to the second timing signal issued by the clock corresponding to said ending time; said memory comprising data storage means for storing updatable timing data for re-powering on the supply of the RF receiver; said clock comprising means for setting time according to said remote-controllable power-saving command; said RF receiver comprising demodulating means for demodulating the received information codes and address code in FM signals.

(5) A pager adapted to the method of invented timing power-saving operation, comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard, characterized in said control keyboard comprising numeric keys for numeric inputs and functional controls, and control keys for operation in association with numeric keys; and means for inputting timing data of the timing power-saving operation and personal password of the owner; said memory comprising storage means for storing updatable password; storage means for storing updatable timing power-saving command data; and storage means for storing updatable timing data regarding the RF receiver's power switching-off time and power switching-on time; said CPU comprising: password verifying means for verifying the keyed-in personal password against the stored personal password, so as to control the pager to execute or to freeze the regular operation functions; power-saving command processing means for storing input data of timing power saving instructions into storage means, and for setting the internal timing clock; and power-saving command executing means for forcing the pager into power-saving operation mode and stopping RF receiver temporarily from receiving, or for restoring the pager to regular operation mode and resuming reception of messages by RF receiver, in response to timing clock signals; said clock comprising means for setting time according to the input timing power saving data; said RF receiver comprising demodulating means for demodulating the receiver information codes and address code in FM signals., (6) A pager adapter to the method of invented divided batch power-saving operation, said pager comprising RF receiver, decoder, CPU, clock, memory, display screen and control keyboard; said pager operating on the basis of regular POCSAG power-saving mode, and having preassigned the pager's address and messages in batch m, frame n of a paging format, where both m and n are ls or positive integers greater than 1, characterized in: said memory comprising: storage means for storing chanageable batch number m and frame number n; said CPU comprising: divided batch receiving control means, for identifying the first sync code after preamble in received signals, or the end code of said pager's paging messages, and for shutting-off the RF receiver and forcing the pager into power saving operation mode, in response to either one of aforesaid codes; divided batch receiving execution means, for setting the clock according to the timing value, calculated by the formula S=(m-l)xM+(n-l)xN, in response to the identified first sync signal, where m is the batch number and n is, the frame number, both being stored in the pager, M and N are respectively the times laped in one batch and in one frame according to the paging information format, and for turning-on the RF receiver to receive the paging signals in batch m, frame n, according to the timing signals issued by the set clock;; said RF receiver comprising demodulating means for demodulating the received information codes and address code in FM signals; said clock comprising means setting time according to the times determined by the aforesaid S values.

Said various schemes of MPSO under the present invention, and the designed pagers adapted to MPSO, are obviously suitable for various paging environments and meeting the needs in different usages.

They provide extremely good flexibility in operation, and can achieve better power-saving results than conventional ordinary method of power saving.

Brie description of the drawings The following are further explanations expounding on said invention by means of related drawings, wherein: Fig. 1 is a schematic showing the structural principles of a pager adapted to the invented MPSO.

Fig. 2 illustrates a regular paging message format, and the power supplying condition (schematic) for a pager adapted to ordinary power saving techniques.

Fig. 3 shows schematically the power supply condition for a pager adapted to the invention remote-controllable power saving scheme.

Fig. 4 is the front view of a numeric key controlled pager on which the invented timing power saving scheme may be inplemented.

Fig. 5 is a flowchart showing the principles of timing power saving operation as implemented on a numeric key controlled pager as in Fig. 4.

Fig. 6 shows the power supply condition in schematic, as implemented on a pager adapted to the invented timing power saving operation.

Fig. 7 shows the current supply condition in schematic, as implemented on a pager adapted to the invented divided batch power saving operation.

Detailed description of the preferred embodiments Fig. 2 above has been explained in the first half of the Description. The following starts with further explanations in conjunction with Fig. 3.

Figs. 3a and 3b show respective cases corresponding to a prior art regular POCSAG power saving operation, and to the invented remote-controllable power saving operation.

In Figs. 3a or 3b, the upper curve is representative of the data format for pager messages1 and the lower is representive of the power supply current pulses for the pager. In the curve for paging data format, P is a preamble, SC a synchronization cpdeword, F5 the fifth frame. Assuming the pager has an address related to the fifth group, Fig. 3a is now analysed. As the preamble signal reaches a pagers, the CPU, following a predetermined design, controls to keep the power supply on until the pager receives a successive SC of batch 1, then the power is switched off.

Thereafter when SC and the fifth frame, to which the pager relates, appears, the power is automatically turned on again. The decoder checks whether the address code in the received message is identical to the une o the pager. When the address is confirmed, then the power supply to the pager remains connected until the end of the message. For every SC and every frame 5 of every batch, the power supply is turned on automatically.

The power switch of the RF receiver, is controlled by CPU via a power saving control wire. The CPU follows a predetermined power saving scheme, to control the switch of the RF receiver. According to regular POCSAG code, power of the RF receiver will be supplied for picking up signals only when the preamble, or sync code, or the related frames are detected. According to the POCSAG format, a plurality of batches are followed after a preamble. Each batch consists of 1 SC and 8 frames. Each frames consists of 2 codewords representing either address code or message codes. Pagers are divided into 8 groups. The address code of a pager appears only in the frame corresponding to its own group. It is only necessary for a pager to power up its RF receiver during the related frame, to pick up all its address and messages.To summarize, the power-on period of a RF receiver starts only with the preambles, the sync codes, and one of the 8 frames.

The ordinary power-saving method as implemented on the pagers adapted to regular POCSAG standards has been described as above.

However to implement the invented method on the pagers adapted to MPSO, different schemes have been devised.

When the power-saving wire powers up the RF receiver, a signal (a frequency-modulated signal with a mixed content of address code and message codes) is picked up by an antenna, and demodulated by the RF receiver. The address signal will be demodulated first, and after demordulation it is sent to a decoder for decoding, and checked for validity with the stored address code (in the storage means for address codes). If the addresses are identical, the RF receiver will carry on decoding the information signals, and send the signals to decoder for decoding.

The signals picked up by the decoder, are signals formed in POCSAG standard code and format, comprising 1 message bit, 20 information bits, 10 redundant check bits, and 1 even parity bit. Decoding program for the decoder is to utilise the 10 redundant check bit to check out and correct error bits (if any). The next task is to check the message bit. If it is "0", then the information bits represent an address, and the information-bits are checked against pager's stored address. If identical, then the succeeding signals are to be decoded, otherwise the decoder notifies the CPU to shut off the RF receiver, pending suitable time to reopen the receiver.

If the message bit is "1", then the signal contains information codes, and the decoder sends the 20 bit decoded information to CPU.

As the CPU receives information codes, the bits are stored into memory, whereas the time information can meanwhile be extracted from the clock, and store it in memory. Assuming the alarm mode is set as "beep", CPU invokes a loudspeaker which then gives out audio-alarm to alert the owner that a message is forthcoming. If alarm mode is set as "vibrate", the CPU sets off a vibrator which vibrates to alert the owner that a message is forth- coming. If the alarm mode is set as "quiet", CPU invokes neither the loudspeaker nor the vibrator1 but a pilot lamp blinks to alert the owner. of a waiting call. During the period of alert, if any key is pressed, the alert will cease. If no key is pressed at all, the alert will also stop automatically after a predetermined period of time.

In the same time that the alert is issued, the received message and its arrival time may be displayed on the LCD screen under the controll of the CPU. When the alert is press-stopped or auto-stopped, the message will remain displayed for a period of time, to allow sufficient time for the owner to read the message.

If during message display, the photosensor detects a poor level of lighting, the CPU then invokes a penal light, to enhance message visibility to the owner even in a poor lighting environment. When the message display is complete, the CPU will cut off the panel light, and will display other information like time of the day, etc.

Information stored in the memory may be retrieved at any time, provided a key is pressed, and the information is displayed on a LCD screen. The information is stored in a last-in-first-out arrangement, i.e., the first retrieved piece of information is the last entered piece. After the first piece is retrieved, a next piece will continuously be displayed if the same key.is pressed again, until keypressing stops. The the last retrieved piece remains on screen for a time period, then other information will be displayed.

If during the period of pager operation, when low battery detector senses the battery voltage weakening to below operational level, the CPU will issue a warning signal, and the display screen also shows up a low battery warning message, to notify the owner to change battery. This low battery warning message is displayed from time to time until old battery is replaced.

On the pager which adapts to a method of numeric key control, the numeric keys are used for information retrieval by direct entering the label number of the required message or information , and the last-in-first-out sequential display ' no ionger applies. By pressing one of the ten numerics in association with the overleaf/enter key, functional selection of the required message is achieved according to the label digits.

The lower curve of Fig. 3b is the power supply current cruve of a pager adapted to the power saving of the first kind, i.e., the remote-controllable power saving. According to the invented MPSO, a message is sent from the paging station to a pager, commanding the pager to stop receiving for a specified period, to turn off the RF receiver circuit, to render the CPU entering a napping state, and to allow only a limited number of functions of the CPU to operate. After that period, the CPU is awakened to restore its normal state of receiving messages. Thus power saving scheme is mostly used for night times and holidays, to work on intermittent pagcr operation.Since during those times much fewer messages are sent to a pager, if messages are received by a normal power-saving operation, the pagers has to connect the RF receiver with battery at the appearance of every sync code, and of every related frame.

Because the pager is not busy at these times the pager has only few messages to receive; in this case, to run the pager in normal power-saving way is still a waste of battery energy. To implement the present invention, when the pager enters the remote-controllable power saving scheme, relevant procedures are the following: The information codewords in the signals transmitted by the paging station to the pager, include, after the address codeword, a command to begin remote-controllable power saving and length of the pause (ordinarily the pause varies from seconds to hours). Under normal conditions, when the related frame affears, the pager powers-on the RF receiver, and commands the CPU to work regularly for message reception. Then the decoder checks the identity' of an address code. If this is confirmed, then compare the received address code with the address code in memory.If there are identical codes, then the subsequent information codewords are read. With our invented MPSO, if a command for remote-controllable power saving is sent by the paging station, the CPU in the pager can identify the command and immediately starts controlling the related means and executes relevant procedures. The RF receiver is powered off; the CPU is sent to nap; only the pager clock is kept running for timing control and limited CPU functions are maintained in operation, to calculate the pause time and to awaken the pager after a predetermined period of time, for returning to normal power-saving operation For example, a pause (e.g., for 30 seconds) command for remote-controllable power saving is sent from paging station to a pager.As shown in the Fig. 3b format, the address codeword in the fifth frame of a paging signal incorporates a common address (for use by all related pager for identification) in the address codeword, and a 30 second pause command in the information codeword. During the POCSAG power-saving operation, the pager picks up its own address code in a related frame, and subsequent information codes as well. The CPU identifies the information to be a remote-controlled pause command for 30 seconds, and immediately starts the relevant procedures, namely, to switch off RF power supply, to restrict the CPU operations (or, to enter power saving state), and to set the timing clock for a 30 second control. When the 30 second is up, all operations will be resumed, the RF receiver is powered on automatically, and the situation continues until a sync code is received then power is-cut off again.In this manner, the pager follows the invented MPSO of the first kind, i.e., remote-controllable power saving, to realize a power-saving operation.

The following narration explains timing power saving.

The similarity between remote-controllable and timing power saving is to effect an intermittent pager run, for example, to effect the RF receiver on daily scheduled periods to stop running and not to receive any message during those periods, until the timing power saving command is relieved. Quite a number of owners expect no messages after working hours or at night, and they wish to run off the pager until next morning. Yet they tend to forget at times, either to turn the pager off all night resulting in wasting battery power, or to turn the pager on in the morning to miss. some early messages. It is with this aim that the timing power saving is devised, so that a pager clock will follow the command to calculate properly the on-off time.

To implement the timing power saving, several approaches are available: A. Timing schedule is set by manufacturers of the pager. The schedule includes daily shutting off RF receiver, keeping CPU operation for very limited functions, and resuming the pager1s normal run at another time of the day. This schedule is fixed in the pager. Change of schedule by owner is impossible and must be done by manufacturers or service station.

B. Command is sent by paging station to the pager having this function, in a manner similar to sending the command for remote-controllable power saving. Besides the command, transmission also includes power on-off timing. After the CPU identifies this timing power saving command, the pager will receive the subsequent data and store them as a guide for power on-off schedule. The cPU counts the actual time by means of the internal clock. At the power-off time, the CPU executes a power saving procedure. At the power-on time, the CPU executes a function-resumption procedure. The owner can inform the paging station to change the on-off schedule or even to cancel this function.

C. If the pager is numeric key controlled, selection of the timing power saving mode can be done through the numeric/function keys and enter key. After entering a personal password, the power on-off time can be entered through the numeric keys. Then the CPU will execute relevant procedures, like in B above, on schedule. Of course, the owner can change the on-off schedule at any time and wnto whatever schedule he might desire, or even cancel this function.

In order to explain a typical timing power saving operation, it is necessary to describe a numeric key controlled pager, on which said MPSO is implemented. Fig. 4 is the front view of a pager for numeric key control, with 3 function keys, labelled respectively, upshift key 1, downshift key 2, overleaf key 3, which may perform the functions of ',overleaflenter1l. In addition, there are ten numeric keys also performing the functions of 11numeric/function", being labelled respectively with numbers 0-9. The basic functions are: KEY NAME FUNCTION E - W numericffunction numeric input or function selection keys (in association with enter key).

# upshift key selective display of preceding message item downshift key selective display of succeeding message item 2 overleaf/enter message length exceeding screen key display, this key allows reading of next page. Where no message is received, this key is used in association with the 0-9 keys as either numeric keys or function keys.

Pressing any one numeric key (one of the 0-9 keys) represents an assigned function. For examp]e, numeric key E is assigned a password processing function. When numeric keyDis followed by the pressing of 2 key, a functional command for processing a password is activated. And, through pressing and E , the timing power saving command is entered.

Fig. 5 is a flowchart showing the principles of the invented timing power saving function as implemented on a numeric key controlled pager.

The program begins with the owner selecting a timing power saving function through manipulating the numeric keys and control keys on the keyboard. After selection, the pager awaits the owner to. enter a correct password. When this is done, the procedures in the pager begin to verify this password. If the password is valid, then the next step is to accept the starting time (e.g., 5:00p.m.) and the stopping time (e.g., 9:00a.m.) for pager's power saving operation as keyed in by the owner. Hence the pager automatically executes the power saving function during this period. If the owners password is not verified, then the pager does not execute the next procedure, but rather requests the owner to reenter password, and rechecks the new password. If the owner enters password wrongly for many times (e.g., 8 times), then the pager automatically enters a frozen state, in which regular paging functions become inoperative temporarily.

Fig. 6 shows the power supply current curves in schematic, as implemented on a pager adapted ' to the invented timing power saving. Fig. 6a is the data format for paging messages in regular POCSAG power-saving operation and power supply current curve (similar to Fig. 3a), to be compared with the invented timing power saving curve in Fig. 6b. The upper curve of Fig. 6b assumes that owner Is information is contained in the fifth frame, and that the pager operates in the invented timing power saving operation, from 5:00p.m. to 9:00a.m., so that the pager's receiving time is from 9:00a.m. to 5:00p.m.. After the pager begins to work, it runs under POCSAG power-saving operation, and receives a real time signal in its related frame to calibrate the actual time of the pager.If the real time signal is received at 9:00p.m., the RF receiver of the pager immediately stops working, and the CPU begins to count real time with its clock. When the time is 9:00a.m., the CPU resumes all paging operations, and follows POCSAG power-saving operation. During this time, the CPU still counts time and receives the real time signals for calibration. At 5:00p.m., the pager automatically enters a state of stopping receiving; until 9:00a.m. next day when the pager resumes operation.

The following is a description of divided batch power saving.

Fig. 7 shows the power supply current curves in schematic, as implemented on a pager adapted to the invented divided batch power saving. Fig. 7a is the data format for paging messages in regular POCSAG power-saving operation and power supply current curve. Fig.

7b is the data format for paging message and power supply current curve for the invented divided batch power-saving operation. Fig.

7a assumes the owners paging message in the fifth frame; Fig. 7b assumes the owner's paging message in the fifth frame of the second batch. Fig. 7a shows the pager has to receive messages once in a batch according to the standard POCSAG format; Fig. 7b shows a different scheme in which the owner's message only appears in a specified batch, such that th pager only need to receive messages in the specified batch. For example, in Fig. 7b, the address code of the pager is specified to relate to group 5, and reception is specified to be from batch 2 only. The power supply is kept connected right after receiving preamble, and is later cut-off.

After receiving the preamble, the CPU begin to count the appearances of sync code for batch numbers. The second sync code received, means a second batch. Therefore the RF receiver is powered on for the fifth frame automatically for message reception.

Therefore the divided batch power saving is an improvement over the regular POCSAG power-saving operation. Not only that power supply is connected when sync code appears and for the related frames, but also counts the batch number after preamble and selects the related frame before the RF receiver is connected, namely, not connected for all related frames in every batch. Some information, for example, the public information, not change often, is infrequently transmitted, or repeatedly dispatched Hence the pager need not require power to check messages for every frame.

This kind of power saving operation may be implemented on a pager design, in coordination with the paging station transmission time, to connect with the battery at the appearance of the effective batch and related frame. This greatly improves the -working efficiency of the RF receiver, and the battery life used in a pager.

To summarize, the processes of executing divided batch power saving are: the pager manufacturers set up on a pager, during which batch after the reception of a preamble, the RF receiver is powered up, according to the nature of the message intended to be received.

And, during other times, the RF receiver is powered off and the CPU operates on limited functions only. The paging station will coordinate with the pager's activities, to arrange in a place in a suitable batch and in a proper frame for a message to be transmitted. After being switched on, the pager is kept connected with battery until a preamble and the first batch sync code is received, then the power should be switched off. Power will be on again when the sync code of the next batch appears, and off after this sync code. The CPU is able to identify the related batch according to the preamble signal and to the count of sync code appearances, and to prepare for powering on the RF receiver for reception of messages at the related frame. The paging station will determine how many batches should be transmitted after the preamble signal.When all batches are sent, the preamble signal and batch messages will be repeated. The pagers operation can be based on these signals.

Fig. 1 is a schematic showing the structural principles of a pager adapted to the invented MPSO. As shown in the figure, the pager comprises antenna, RF receiver, decoder, CPU, LCD display screen, memory, low battery detector, clock, and other input/output devices like loudspeaker, vibrator, pilot lamp, panel lighting, photosensor, and control keyboard equipped with ten numeric keys and three control keys. This keyboard has numeric keys for numeral input and functional controls, as well as control keys to work in association with the numeric keys. Numeric keys are labelled 0-9, and each numeric key will work with the control key to control one or more functions. The control key is provided for direct control of the basic paging functions, for example, displaying a preceding piece of message, displaying a succeeding piece of message, and displaying a full page of message, etc.The control key acts in association with the numeric keys, to realise a dual-function for each numeric key in inputting of numbers and functional control.

Besides, a certain parts or functions of the pager have been described in previous assertions, or similar to the pager described in previous assertions.

The entire operation of a pager is controlled by a CPU. The CPU and memory, in addition to the regular designed configurations and stored programs in order to control the normal operation functions, have various designs and configurations as required by said invention in order to ensure the realization of the invented MPSO on the pager. Hereunder is the working procedures of such a pager, as being explained in association with Fig. 1. As a signal is picked up by the antenna, the signal is demodulated by a RF receiver, which comprises a demodulating means for demodulating the message codes and address code in the frequency-modulated signals.

The RF receiver has a function of stop-receiving in the power saving periods as specified by one of the 3 kinds of MPSO, for the purpose of saving power. The RF receiver also has the function of stop receiving. In particular, the RF receiver has a control means that freezes the receiving operation on a temporarily basis, after the CPU receives a freeze command or after the pager.receives the input of a code to enter a frozen state. In normal operations of the RF receiver, the demodulator first demodulates address signal, and sends the demodulated signal to a. decoder for decoding, and thereafter check the address with the one stored in the address code storage means of the pager. If the addresses are identical, the receiver continues to demodulate the subsequent information code signal, and send it to the decoder for decoding. By means of a special decoding means in the decoder, this task may be accomplished. In a pager employing MNKC, the memory includes a storage means that stores a changeable personal password, a storage means that stores a changeable address, and storage means storing personal messages and public information.In the pager adapted to the invented remote-controllable, timing, and divided batch power saving, the memory further comprises: means for storing the changeable time for repowering the RF receiver in the remote-controllable power saving mode; means for storing the changeable times for shutting off and repowering the RF receiver in the timing power saving mode; or means for storing the changeable batch number in the divided batch power saving mode respectively.

Personal messages and public information are arranged in labelling sequence, for example, the labels for personal messages are 01-99, and for public information, 001-999 or 0001-9999, therefore the object of retrieval by inputting labels can be attained.

The pagers s address, based on this invention and on a method of numeric key control of a pager, is changeable by the owner. This function is performed through a special means in the CPU, namely, according to the correct procedure specified by the invention, an input new address code can replace (update) the old address stored in the memory. In particular, the CPU has a control means to update, according to a keyboard input, the stored data in said personal password storage means, address storage means, decipher keyword storage means. Therefore, the address code in the pager is changeable or assignable by the owner entering the code through numeric keys. The method of input is first a personal password is entered and checked. If the password is correct, then the requirement to change the address needs to be confirmed.If affirmative, a new address may be entered, and the pager henceforth uses this new address to receive calls. Or else the address is unchanged, and the pager continues to use the old address in receiving. If, however, the password is incorrect, a new password needs to be input again. If after n consecutive times (where n is integer greater than 1) the password thus entered are all wrong, the pager goes to the frozen state, and becomes functionally inoperative temporarily, and its functions may resume only after a "de-freeze" process. The "de-freeze1, process begins with a personal password entering and checking. If correct, then the pager may be de-frozen and resume all functional operation. If incorrect, the password should be re-entered.If the passwords are incorrect for n consecutive times (where n is integer greater than 1), the pager then enters into a second class frozen state, and the pager can only be returned to a paging centre, to resume all functional operations by a special de-freezing equipment. By means of special means in the CPU, the input personal password is checked against the stored personal password in the memory, so as to control the pager in its execution of various normal functional operations (when the input password is correct), or else, the pager has its normal functional operation frozen in the way described above in this Description (as said in previous narrations, when the password is wrong for a consecutive times).

In addition, personal passwords can be changed through numeric keys. The changing process is that first the old password is entered. If the password is correct then a new password can be input, which will take immediate effect. Thereafter, the password has been changed from the old to the new. If during the course of change, password is wrong, then old password has to be re-entered.

If, however, the password has been incorrect for a consecutive n times (where n is integer and greater than 1), the pager will enter a frozen state, and temporarily inoperative, and must go through a "de-frozen1' process to recover the functional power. "De-freeze" process is stated in the above paragraph. By means of a special means in CPU, the required control. function can be accomplished, which is to replace (update) the old personal password in the stored memory by inputting a new password, according to the correct operating steps of the invented method.In particular, CPU has a password checking means to check a keyboard-input personal password against the stored personal password, so as to control the pager to execute or to freeze its normal operations; a freezing means that decodes the frozen signal in signals received, and controls the pager to freeze the normal functions of the pager according to a decoded freeze command; and a means that controls the RF receiver, keyboard, display screen, and other input/output means to temporarily stop the functions of these of means under a frozen state.

The signals picked up by the decoder, are signals formed in POCSAG standard code and format, comprising 1 message bit, 20 information bits, 10 redundant check bits, and 1 even parity bit. Decoding program for the decoder is to utilise the 10 redundant check bit to check out and correct error bits (if any). The next task is to check the message bit. If it is "0", then the information bits represent an address, and the information bits are checked against pager's stored address. If identical, then the succeeding signals are to be decoded, otherwise the decoder notifies the CPU to shut off the RF receiver, pending suitable time to reopen the receiver.

Information received by a pager with numeric keys, can be coded in cipher (cryptograph) so that messages may be transmitted in secrecy. Even if a third person "intercepts" the message, he may not be able to understand the true information without a "decipher keyword". Therefore, in the CPU, a means is provided which can read any enciphered message coming in from the decoder, and which can decipher it by plugging in the decipher keyword stored in the memory.

Each pager model may have different "decipher keywords". The owner may input his own "decipher keyword" or change it, through the numeric keys, and then notifies the paging centre to encipher the messages according to the corresponding "encipher keyword", thus the transmission of information is kept in personal secrecy. The procedure for changing a decipher keyword is, first, a personal password is input for inspection. If correct, then the decipher keyword may be entered. After the new keyword is entered, under the control of a special control means provided in the CPU, the new keyword replaces (updates) the old decipher keyword stored in the memory, so that the new keyword takes effect immediately and with which the pager deciphers messages. In particular, the CPU provides a decipher means for deciphering cryptographed messages in the received signals by means of a stored decipher keyword. If the input personal password is wrong, ' the password should be re-entered. if it is wrong for n times (where n is integer greater than 1), the pager wil enter the frozen state, rendering its functions inoperable, and the pager will.resume functioning only after a "de-freeze" process, which has already been described above. The CPU has provided a special means for this purpose.

When the pager enters a state where its general functions have been frozen, i.e., its normal operating functions have been withheld, the pager will check any input personal password against the stored personal password. If the two are identical, the pager will resume normal operation. When the password is consecutively wrong for n times (where n is integer greater than 1), then the pager will enter a second class frozen state. At this time, all function should fail, and the pager can only be returned to the paging centre, and de-frozen by a specialised equipment, before the pager will resume operation.In particular, the CPU has a control means that, when the pager enters a state of normal operation functions being frozen, will check any input personal password against stored personal password, and will control the pager in resuming the function of normal operation, or entering another state where the pager needs to be de-frozen by the paging centre's equipment before resuming the functions of a normal operation.

In a pager adapted to the invented timing or remote-controllable power saving, the CPU should further comprise: power saving command processing means for controlling the storage of input data in a timing power saving command, or in a remote-controllable power saving command, into the storage means, and also for processing the power saving commands in order to set time on the internal clock; power saving command executing means to direct the pager going into a power saving operation, as well as to resume normal operations, according to timing signals from internal clock. Furthermore, in a pager adapted to the three invented MPSO, the internal clock also comprise means for setting respective times according to the data from the remote-controllable power saving command,' or from the timing power saving command, or according to the batch number of the divided batches respectively.

In addition, in order to prevent message leak-out in case the pager is mislaid or not held in owner's hand, it necessitates a remote freezing function. This function sends out a freeze command to render a pager's operations partly and temporarily ineffective.

The so call freeze command is a special commandl in the form of a message. When the pager is frozen, it will resume normal operation only after going through a "de-freeze" process. For this purpose, the CPU provides a special means, for decoding the freeze signal in the signals received, controlling the pager on the decoded freeze command, and withholding its normal operation functions, i.e.

rendering the pager to enter a frozen state.

As the CPU receives information codes, the bits are stored into memory, whereas the time information can meanwhile be extracted from the clock, and store it in memory. Assuming the alarm mode is set as beep, CPU invokes a loudspeaker which then gives out audio-alarm to alert the owner that a message is forthcoming. If alarm mode is set as "vibrate" the CPU sets off a vibrator which vibrates to alert the owner that a message is forthcoming. If the alarm mode is set as "quiet", CPU invokes neither the loudspeaker nor the vibrator, but a pilot lamp blinks to alert the owner of.a waiting call. During the period of alert, if any key is pressed, the alert will cease. If no key is pressed at all, the alert will also~stop-automatically after a predetermined period of time.

When the alert is issued, the message is not seen on the display screen, and instead, a request for "entering a password" is shown.

At this juncture, if the owner enters a correct password, the message does show up, or else the owner has to re-enter the password until it is correct. If the password is mistaken for more than n consecutive times (where n is an integer greater than 1), then the pager will enter the frozen state. The owner has to go through a "de-freezeo process to have the pager de-frozen.

Therefore, the CPU has a means for controlling the display screen so that no received messages will be displayed right away, under this secret mode of display protection, but the owner's entering of password is first prompted.

When the alert. is press-stopped or auto-stopped, the message will remain displayed for a period of time, to allow sufficient time for the owner to read the message. If during message display, the photosensor detects a poor level of lighting, the CPU then invokes a penal light, to enhance message visibility to the owner even in a poor lighting environment. When the message display is complete, the CPU will cut off the panel light, and will display other information like time of the day, etc.

Information stored in the memory may be retrieved at any time, provided a key is pressed, and the information is displayed on a LCD screen. The information is stored in a last-in-first-out arrangement, i.e., the first retrieved piece of information is the.

last entered piece. After the first piece is retrieved, a next piece will continuously be displayed if the same key is pressed again, until keypressing stops. The the last retrieved piece remains on screen for a time period, then other information will be displayed.

On the pager which adapts to this invention, the numeric keys are used for information retrieval by direct entering the label number of the required message or information , and the last-in-first-out sequential display no longer applies. By pressing one of the ten numerics in association with the overleaf/enter key, functional selection of the required message is achieved according to the label digits, and this function is realised by the help of a special means in the CPU. In particular, the CPU provides a control means for storing the message consecutively into the storing means for personal messages and public information according to their labeled numbers, and displaying the message or information according to the control of numeric keys.That is to say, it is intended to first categorise and label the received data representative of various personal messages and public information according a predetermined classification, and to store them into memory through control; then to retrieved one specified piece of message and send it to screen display according to the numeric key control (as having already been described in association with Fig.1). Therefore the CPU has a further means for use to control keyboard, and to identify numeric inputs, selected functions and numeral digits, so as to realise all said novel functions on a pager adapted to the MNKC. Furthermore, before the time of message display, the owner is requested to enter password through numeric keys, which is checked for validity, to yield a result of keeping the confidentiality of the messages. In case of the entered password being mistaken for more than n consecutive times (where n is integer greater than 1), the pager will enter automatically a frozen state, in which its functions are withheld temporarily, and may not be resumed before going through a "de-freeze1, process.

The above is merely an explanation of this invention by way of a number of concrete and preferred embodiments. However, this invention is in no way be confined to these embodiments. Persons skilled in the art may design various modifications or variations of this invention, based on the ideas and essence of the invention, but all of which may not go beyond the scope of this invention.

Claims

1. A method of power-saving operation for pager, said pager comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard; and operating using standard POCSAG power-saving format; said method comprising the following procedures: a. after the pager receiving a calling signal, the decoder decoding remote-controllable power saving message embedded in the information code, and sending the decoded message to CPU for processing; b. power-saving command processing means in CPU identifying the decoded message as a remote-controllable power saving command, which includes the instructions for specified starting time and for ending time of power saving operations; c. the power-saving command processing means in CPU setting the clock respectively according to the power-saving starting time and the ending time instructions; d. on the arrival of a specified power-saving beginning time as detected on the clock, power-saving command executing means of CPU forcing the pager to enter said power-saving operation mode in response to a first timing signal issued by the clock; e. on the arrival of a specified power-saving ending time as detected on the clock, the power saving executing means of CPU forcing the pager to resume its normal operation mode in response to a second timing signal issued from the clock.

2. A method of power-saving operation for pager, said pager comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard, and operating using standard POCSAG power-saving format; said method comprising the following procedures: a. owner selecting timing power-saving function, through manipulating the numeric keys and control keys on the control keyboard, and the pager awaiting the input of a personal password; b. owner inputting a predetermined numerical sequence representative of his personal password, through manipulating numeric keys; c. pager verifying the validity of said personal password: d. if password being valid, then pager accepting owner's instructions, that have been input through numeric keys, of a spedified daily beginning time and ending time for power saving.

d-1. power-saving command processing means of CPU storing into special storage means in memory, the said instructions of beginning time and ending time for power saving, and setting the clock every day according to the beginning time and ending time; d-2. on the arrival of the power saving beginning time, as specified on the clock, power-saving executing means of CPU forcing the pager to enter said power-saving operation mode in response to a first timing signal issued from the clock; d-3. on the arrival of the battery-saving ending time, as specified by the clock, the CPU forcing the pager to resume normal operation mode in response to a second timing signal issued from the clock; e. if password being invalid, then pager awaiting a second password input, and repeating said password verifying procedures, until password being entered wrongly for n consecutive times (where n is integer greater than 1) then the pager entering a frozen state.

3. A method of power-saving operation for pager, said pager comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard; and operating using standard POCSAG power-saving format, and in the paging message format, the pager1 S address and information being specified as in batch m and frame n (n, m is unity or positive integers greater than 1); said method comprising the following procedures: a. after the pager receiving a calling signal, the first sync signal after preamble in the received message signal being identified by divided batch receiving control means of the CPU, and CPU forcing the power supply of the RF receiver being switched off and forcing the pager to enter a state of power-saving operation after the first sync signal being over; b. divided batch receiving execution means of the CPU setting the clock according to the S value, calculated by the formula S=(m-l)xM+(n-l)xN, in response to the identified first sync signal, where m is the batch number and n is the frame number, both being stored in the pager;M and N are respectively the times laped in one batch and in one frame according to the paging information format; c. in response to the timing signal issued from the clock at the times indicated by S, the divided batch receiving execution means of the CPU forcing the RF receiyer being powered-on, allowing the pager to receive said paging message in frame n, batch m, as being specified; d. after said paging messages end, the divided batch receiving control means of CPU switching off the supply to RF receiver and forcing the pager to enter the state of power saving operation again.

4. A pager adapted to the MPSO, comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard, characterized in said CPU further comprising: power-saving command processing means, for identifying a decoded remote-controllable power saving command from decoder, (said command including instructions of specified beginning time and ending time of power saving operation), storing data of said command into memory, and setting the internal clock according to said beginning time and ending time; and power-saving command executing means, for forcing the pager into power saving mode and temporarily stopping the reception function of RF receiver, in response to the first timing signal issued by the clock corresponding to said beginning time; and for restoring the pager back to normal operation and resuming the reception function of RF receiver, in response to the second timing signal issued by the clock corresponding to said ending time; said memory comprising data storage means for storing updatable timing data for re-powering on the supply of the RF receiver; said clock comprising means for setting time according to said remote-controllable power-saving command; said RF receiver comprising demodulating means for demodulating the received information codes and address code in FM signals.

5. A pager adapted to the MPSO, comprising: RF receiver, decoder, CPU, clock, memory, display screen and control keyboard, characterized in said control keyboard comprising numeric keys for numeric inputs and functional controls, and control keys for operation in association with numeric keys; and means for inputting timing data of the timing power-saving operation and personal password of the owner; said memory comprising storage means for storing updatable password; storage means for storing updatable timing power-saving command data; and storage means for storing updatable timing data regarding the RF receivers power switching-off time and power switching-on time; said CPU comprising: password verifying means for verifying the keyed-in personal password against the stored personal password, so as to control the pager to execute or to freeze the regular operation functions; power-saving command processing means for storing input data of timing power saving instructions into storage means, and for setting the internal timing clock; and power-saving command executing means for forcing the pager into power-saving operation mode and stopping RF receiver temporarily from receiving, or for restoring the pager to regular operation mode and resuming reception of messages by RF receiver, in response to timing clock signals; said clock comprising means for setting time according to the input timing power saving data; said RF receiver comprising demodulating means for demodulating the receiver information codes and address code in FM signals.

6. A pager adapter to the MPSO, said pager comprising RF receiver, decoder, CPU, clock, memory, display screen and control keyboard; said pager operating on the basis of regular POCSAG power-saving mode, and having preassigned the pager's address and messages in batch m, frame n of a paging format, where both m and n are l's or positive integers greater than 1, characterized in: said memory comprising: storage means for storing changeable batch number m and frame number n; said CPU comprising: divided batch receiving control means, for identifying the first sync code after preamble in received signals, or the end code of said pager's paging messages, and for shutting-off the RF receiver and forcing the pager into power saving operation mode, in response to either one of aforesaid codes; divided batch receiving execution means, for setting the clock according to the timing value, calculated by the formula S=(m-lJxM+(n-l)xN, in response to the identified first sync signal, where m is the batch number and n is the frame number, both being stored in the pager, M and N are respectively the times laped in one batch and in one frame according to the paging information format, and for turning-on the RF receiver to receive the paging signals in batch m, frame n, according to the timing signals issued by the set clock; said RF receiver comprising demodulating means for demodulating the received information codes and address code in FM signals; said clock comprising means setting time according to the times determined by the aforesaid S values.