CA1196964A - Pager receiver comprising a message detector energized only at pertinent time slots - Google Patents
Pager receiver comprising a message detector energized only at pertinent time slotsInfo
- Publication number
- CA1196964A CA1196964A CA000419817A CA419817A CA1196964A CA 1196964 A CA1196964 A CA 1196964A CA 000419817 A CA000419817 A CA 000419817A CA 419817 A CA419817 A CA 419817A CA 1196964 A CA1196964 A CA 1196964A
- Authority
- CA
- Canada
- Prior art keywords
- call
- message
- code
- time slot
- calling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000000007 visual effect Effects 0.000 abstract description 3
- 238000001514 detection method Methods 0.000 description 4
- 238000001208 nuclear magnetic resonance pulse sequence Methods 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 238000013519 translation Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B5/00—Near-field transmission systems, e.g. inductive loop type
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
- H04W52/0225—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal
- H04W52/0229—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal where the received signal is a wanted signal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/02—Terminal devices
- H04W88/022—Selective call receivers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Abstract
Abstract of the Disclosure In a pager receiver of a paging system, a reception controller is kept operable when a switch is closed. A first transistor energizes a receiver part at the beginning of a call code part of a received calling signal. If a calling code for that receiver is detected at a certain call time slot of the call code part, the first transistor maintains energization until the end of that call code part and again energizes the receiver part during a message time slot corresponding to that call time slot in a message code part which next follows that call code part in the received calling signal. A second transistor energizes a display part a little before that message time slot. If a message code is detected at that message time slot, the second transistor maintains energization to generate an alert tone and a visual display. As soon as a blank message pattern is detected at that message time slot) the second transistor suspends the energization. It is preferred that a calling code for any one of pager receivers of the system be placed nearer to the beginning of the call code part and that a blank call pattern be placed in each call time slot where no calling code is present. As soon as the blank call pattern is detected, the first transistor suspends energization without waiting for the call code part end.
Description
This invention relates to a pager or paging receiver for use in a paging system. More particularly, the pager receiver is of the type which is not only for info~ling the user of a call but also is capable of displaying a message or the like.
While carried by the user movable within a service area of a paging system and rendered active or operative, a pager receiver must always be ready for detecting a call which may reach that pager receiver at any time from a trans-mit~ing station of the system on a radio calling signal. The power for use in receiving the radio calling signal and indicating the call, is supplied from a battery carried by the receiver.
In order to reduce the power consumption in the receiver, it is cus-tomary to resort to a battery saving scheme as called for in tne art. According to the scheme, pager receivers of the paging system, either rendered active or kept inactive, are divided into a predetermined number of groups. Each frame of the radio calling signal is divided into a plurality of subframes which are allotted to the respective groups as will be described later. A conventional pager receiver for use in such a paging system comprises a receiver circuit for receiving the radio calling signal and for detecting a calling code pre-assigned to the receiver under consideration and an on-off control circuit for automatically energizing the receiver circuit only during the subframe allotted to the group which includes the receiver in question.
~n the other hand, it is a recent trend to make the radio calling signal include a message code which accompanies the calling code for a pager receiver and is representative of a message to be conveyed to that pager re-ceiver. An example of such a pager receiver is disclosed by Alfred B. Levine in United States Patent No. 4,336,524 which issued on May 12, 19~0. The subframe ~6~
becomes accordingly long. As will become clear as the description proceeds, it has now been found possible unexpectedly to save the battery in such a pager receivcr .
It is therefore a general object of the present invention to provide a pager receiver wllich is capable of receiving a message and in which the power consumption is reduced to a minimum.
It is a specific object of this invention to provide a pager receiver of the type described, in which the power consumption is further reduced when the traffic is not busy.
According to this invention, there is provided a pager receiver com-prising first through fourth means as follows.
The first means is for receiving a radio calling signal comprising a call code part and a message code part. The call code part has a preselected number of call time slots. The message code part has a plurality of message time slots which correspond to the call time slots, respectively. The call time slots and the message time slots are time sequentially arranged.
The second means is coupled to the first means for detecting a calling code preassigned to the pager receiver and for deciding which one call time slot of the call time slots contains the calling code detected.
The third means is coupled to the first means through the second means for detecting either of a message code and a blank message pattern in one message time slot of the message time slots that corresponds to the afore-mentioned one call time slotO
The fourth means is responsive to the above-described one call time slot for energizing the first and the third means substantially at a leading edge of the above-mentioned one message time slot.
6 ~
Brief Description of the Drawing:
Figure l is a block diagram showing a transmitting station together with a pager receiver according to a preferred embodiment of the instant inven-tion;
~ igure 2 exemplifies the format of a radio calling signal which is to be received by the pager receiver illustrated in Figure l;
Figure 3 is a schematic time chart for use in describing the operation of the pager receiver of Figure l; and Figures 4(a) and 4(b) together constitute a flow chart for use in de-scribing the operation of the pager of the invention.
Referring to Figure l, a paging system comprises a transmitting station ll having a certain service area. The system further comprises a plurality of pager receivers. Most of the pager receivers are rendered active or operative within the service area during the business hours. Usually, only a few of the pager receivers are kept active in the midnight hours. At any rate, the pager receivers of the system are divided into a predetermined number of groups as described heretobefore. By way of example, let the groups be numbered one through ten groups. One of the pager receivers of the first group is depicted at 12 ~Figure 1) as a representative of the pager receivers of the system.
A plurality of subscriber substations (not shown) are connected to the transmitting station 11. When a call to a desired one of the active pager re-ceivers of the system originates at one of the subscriber subs~ations, the call is transmitted by the transmitting station 11 over the service area on a radio calling signal. It will be assumed that the calling signal is an FM ~frequency modulated) signal.
Turning to Figure 2, each frame of ~he radio calling signal is divided ~6~
into first through tenth subframes sfl to sflO which are allotted to the first through the tenth groups, respectively. As illustrated in detail for the first subframe sfl, each subframe comprises a synchronizing code or word, such as S, a call code part after the synchronizing code, and a message code part after the call code part.
The synchronizing codes have those patterns of binary one and zero bits which are unique to the respective subframes. The pager receivers, such as 12 ~Figure 1), of each group are responsive to the synchronizing code of the subframe which is allotted to that group.
The call code part has a preselected number of time sequentially arranged call time slots or intervals. In the example being illustrated, the call code part of the first subframe sfl immediately follows the synchronizing code S and consists of first through eighth call time slots Al to A8. The message code part immediately follows the call code part and consists of first through eighth message time slots or durations Dl to D8 which are in one-to-one correspondence to the first through the eighth call time slots Al to A8.
In the manner known in the art, the transmitting station 11 (Figure 1) sends a calling code or word in one of the call time slots of one of the sub-frames sfl through sflO in response to a call which originates at a subscriber substation for a desired one of the active pager receivers of the system that is movable within the service area. Such calling codes are preassigned to the re-spective pager receivers, active or inactive, of each group. In order so to preassign, each calling code consists of a prescribed number of binary one and zero bits.
The call may or may not be accompanied by a message to be conveyed to the desired pager receiver. In the presence of a message. the transmitting 6~4 station 11 sends a message code or word in one of the message time slots of the subframe under consideration that corresponds to the call time slot at which the calling code for the desired pager receiver is placed. The message code consists of a certain number of binary one and zero bits which are arranged to represent the message. It is to be noted here that the message, as herein called, should be understood in the broadest sense of the word and may be in-dicative of control of the desired pager receiver.
It is more preferred, when the calling code or codes actually sent in a subframe is less in number than the call time slots of that subframe, that the calling code be placed according to the so-called first-in first-out scheme in each call time slot which is nearer to the synchronizing code, namely, to a leading edge of the call code part and that a blank call pattern be placed in each call time slot at which no calling code is present. For instance, the calling code for the receiver 12 is in the fourth call time slot A~ if sent by the transmitting station 11 in response to a call which originates after the beginning of one frame as a fourth, an eighty-fourth (assuming eight call time slots in each subframe)l or a like one of the calls for the pager receivers of the first group. The blank call pattern should consist of binary one and zero bits arranged in a pattern which is not used as the calling codes for the pager receivers of the group in question. Most preferably, the blank call pattern should consist of b;nary one and zero bits which are arranged as random as pos-sible. Similarly, a blank message pattern is placed at a message time slot at which no message code is present.
Referring back to Figure 1, the pager receiver 12 comprises an antenna 15 for receiving the radio calling signal. An ordinary FM receiving circuit 16 is included for subjecting the received calling signal to frequency conversion~
6~
amplification~ and demodulation. The receiving circuit 16 comprises a discri-minator (not shown~ which produces the demoduated calling signal. A waveform shaper 17 is for shaping the waveform of the demodulated calling signal to pro-duce a reproduction of a digital signal which is produced in the transmitting station 11 to be transmitted as the radio calling signal. Responsive to an alert tone signal which will presently be described~ a driver circuit 18 makes a loudspeaker 19 produce an alert tone. The receiving circuit 16, the waveform shaper 17, and the driver circuit 18 are known in the art. For in-stance, the receiving circuit 16 may be of the type described in United States patent No. 4,194,153, issued on September 14, 1978 to Masaru Masaki et al and and assigned to Nippon Electric Co., Ltd., one of the present assignees. The waveform shaper 17 may be of the structure comprising a low-pass filter and a comparator.
A reception controller 21 is provided for generating a clock pulse sequence and for establishing bit synchronism of the clock pulses. The recep-tion controller 21 is coupled to the waveform shaper 17 so as to detect the synchronizing code S of the first subframe sfl ~igure 2) to provide a reference for use in timing the first through the eighth call time slots Al to A8 and the first through the eighth message time slots Dl to D8. The reception controller 21 is furthermore for timing the call code part~ for detecting the calling code preassigned to the receiver 12 in the first subframe sfl, for deciding that one of the call time slots Al through A8 as a particular call time slot at which the calling code is detected, for producing the alert tone signal as will later be described, and for producing a first and a second control signal which will shortly be described. The reception controller 21 comprises a call memory (not shown) in which a call indication indicative of detection of the calling code ~69~
and the particular call time slot are stored. It is possible to implement most of the reception controller 21 by a large-scale integrated semiconductor circuit ~LSI).
When a switch 22 is closed to render the receiver 12 active, the re-ception controller 21 is supplied with the power from a battery 23 carried by the receiver 12. The power is supplied also ~o the driver circuit 18. The driver circuit 18, however, does not consume the power unless the alert tone signal is delivered thereto from the reception controller 21.
A display unit 26 is provided for visually displaying a message con-veyed to the receiver 12 as a message code at one of the message time slots Dl through D8 that corresponds to the particular call time slot~ When the message is represented only by numerals, the message unit 26 may be a twelve-digit seven-segment liquid crystal display. When the message is alphanumeric, the display unit 26 may comprise a five-by-seven-dot matrix liquid crystal display.
A programmable read-only memory (P-ROM) 27 is for memorizing the call code preassigned to the receiver 12. It may be mentioned here that the receiver 12 may receive a message code and display a translation of the message code as the message according to the key code scheme as called in the art.
In this event, a table for the translation is memorized in the read-only memory 27. Furthermore, -the read-only memory 27 is for memorizing various modes of operation of the receiver 12. For example~ the receiver 12 may be given a function of automatically xesetting the alert tone and the displayed message.
It is also possible ~o render the receiver 12 so as not to respond to the mes-sage code part of the first subframe sfl of the received calling signal. Under the circumstances, the modes of operation are memorized in the read-only memory 27.
A display controller 28 is a one-chip central processing unit coupled to the reception controller 21, the display unit 26, and the read-only memory Z7.
A program for putting the receiver 12 into operationJ is memorized in the dis-play controller 28. Subroutines of the program may be memorized in the read-only memory 27. As will later be described more in detail, the display con-troller 28 reads the calling code from the read-only memory 27 to supply the read-out calling code to the reception controller 21. After timing of the call code part, the reception controller 21 times the message code part. At a mes-sage time slot corresponding to the particular call time slot, the display con-troller 28 is energized, together with the receiving circuit 16 and the wave-form shaper 17, to detect a message code and subject the same to error correc-tion. The display controller 28 comprises a display memory (not shown) for / storing the message which is represented by the error corrected message code or, as the case may be, given by the translation of the error corrected message code.
The display controller 28 delivers the message to the display unit 26 for a visual display as will later be described.
The power is supplied to the receiving circuit 16 and the waveform shaper 17 through a first switching transistor 31, which is controlled by the first control signal. The power is supplied to the display unit 26, the read-only memory 27, and the display controller 28 through a second switching tran-sistor 32 controlled by the second control signal.
Referring furthermore to Figure 3, the calling codes preassigned to eight pager receivers of the first group are present in the -first through the eighth call time slots Al to A8 of the first subframe sfl when the traffic is busiest. It may be that none of the calling codes is for the illustrated pager receiver 12 as indicated in Figure 3 (A) by srosses. Alternatively, the calling code preassigned in the first subframe sfl to the receiver 12 may be present in one of the call time slots Al through A8 together with a message code in the message code part. By way of example, let the calling code for the receiver 12 be present in the fourth call time slot A4 as represented in Figure 3 (B) by a circle 35. The message code under consideration is placed in the fourth message time slot D4 as shown by another circle 36. When the reception controller 21 fails to detect the calling code for the receiver 12 as exemplified in Figure 3 (A), the reception controller 21 makes the first control signal turn the first switching transistor 31 off or nonconductive at the end of the call code part as will presently be described more in detail.
As illustrated in Figure 3 ~C), the reception controller 21 makes the first control signal render the first switching transistor 31 on or conductive when synchronism of the clock pulse sequence is established after closure of the switch 22. When the reception controller 21 detects the synchroni~ing code S
of the first subframe sfl, the reception controller 21 makes the first control signal keep the first switching ~ransistor 31 in the on state. At the fourth call time slot A4, the reception controller 21 detects the calling code which is preassigned to the receiver 12 and is depicted by a hatched area 37. The re-ception controller 21 continues timing of the call code part and makes the first control signal turn the first switching tr~msistor 31 off at the end of the call code part. The reception controller 21 further times the message code part and makes the first control signal turn the first switching transistor 31 again con-ductive substantially during ~he fourth message time slot D4.
As shown in Figures 3 (D) and (E), the reception controller 21 makes the second control signal keep the second switching transistor 32 in the off state at first. The reception controller 21 makes the second control signal ~ ' _ 9 :, , turn the second switching transistor 32 conductive substantially at a ]eading edge of the fourth message time slot D4. If the display controller 28 detects a message code illustrated by another hatched area 38 at the fourth message time slot D4, the reception controller 21 responds to the detection and makes the second control signal keep the second switching transistor 32 in the on state. If the display controller 28 detects a blank message pattern depicted by still another hatched area 39 at the fourth message time slot D4, the re-ception ccntroller 21 responds to the detection and makes the second control signal turn the second switching transistor 32 off substantially at a trailing edge of the fourth message time slot D4.
It is now understood that the pager receiver 12 comprises a receiver part 15, 16, and 17 for receiving the radio calling signal, a reception con-troller 21 coupled to the receiver part for detecting a calling code preassigned to the receiver 12 and for deciding that one call time slot of the call time slots contains the calling code detected, a display part 26, 27, and 28 coupled to the receiver part through the reception controller 21 for detecting either of a message code and a blank message pattern in one message time slot of the message time slots that corresponds to the afore-mentioned one call time slot, and switching transistors 31 and 32 responsive to the above-described one call time slot for energizing the receiver part and the display part substantially at a leading edge of the above-mentioned one message time slot.
As described before, it is preferred that the calling code be placed in less mlmbered call time slot and that the blank call pattern be placed in each call time slot at which no calling code is present. In this event, the blank call pattern may be memori~ed in the reception controller 21. When the traffic is not busy, an appreciable number of the blank call patterns may be 969~
presen~ in the call code part of a subframe. Depending on the circurnstances~
the blank call pattern is placed even in the first call time slot Al as indi-cated in Figure 3 (F) by a triangle.
As soon as the reception controller 21 detects the blank call pattern in any one of the call time slots Al through A8, the reception controller 21 makes the first control signal turn the first switching translstor 31 off as exemplified in Figure 3 ~F). The reception controller 21 subsequently makes the first control signal turn the first switching transistor 31 conductive substan-tially at a leading edge of a next following first subframe sfl as indicated in Figure 3 ~C) by a dashed line sfl' while making the second control signal keep the second switching transistor 32 in the off state.
Referring additionally to Figure 4, it will be presumed that the pager receiver 12 is operable in response to a radio calling signal according to the more pre~erred aspect of this invention and that the switch 22 is closed at a first stage 41 to put the receiver 12 into operation. The reception controller 21 is energized to turn the first switching transistor 31 instantaneously on as indicated at a second stage 42 while beginning to generate the clock pulse se-quence. It is preferred that the reception controller 21 momentarily render the second switching transistor 32 also on to make the display controller 28 transfer the calling code for the receiver 12 and the blank call pattern to a memory in the reception controller 21 from the read-only memory 27. The second switching transistor 32 is kept in the off state until an instant which will later be described.
As illustrated at a third stage 43, synchroni7ation of the clock pulse sequence is carried out. Establishment of the synchronism is checked at a fourth stage 44. If not, the stage 44 returns to the second stage 42. If the synchronism is established, the reception controller 21 tu~ns the first switch-ing transistor 31 again on at a fifth stage 45. Except for an on-off control of the first switching transistor 31 to be presently described and operation of the second switching transistor 32~ the stages 41 through 45 are known in the art.
The reception controller 21 searches for the synchronizing code S of the first subframe sfl at a sixth stage 46. If the synchronizing code S is re-ceived~ the reception controller 21 is put in a state for checking the call time slots Al through A8 one by one as will shortly be described. Even though the synchronizing code S is not detected, the reception controller 21 remains in this state insofar as the synchronism is maintained as shown at a seventh stage 47. After lapse of a certain duration, the synchronism may go out of order.
In this event~ the stage 47 returns to the second stage 42.
While checking each call time slot, the reception controller 21 may find either the calling code for the receiver 12 at an eighth stage 48 or the blank call pattern at a ninth stage 49. If the calling code is received, the reception controller 21 makes the call memory thereof store, as indicated at a tenth stage 50, a call indication indicative of the reception and a particular call time slot at which the calling code is received.
If the received callin~ code is not followed by the blank call pattern as in the busiest hours of the traffic3 the reception controller 21 checks at an eleventh stage 51 whether or not the whole call code part is already dealt with. If not, the search for the calling code and the blank call pattern is repeated. Either upon reception of the blank call pattern or upon completion of the processes for the whole call code part, the stage 49 or 51 proceeds for-ward to a twelfth stage 52 at which decision is carried out as regards necessity and unnecessity of checking the message code part for a message code and the 96~6~
blank message pattern as will shortly be described.
If the blank call pattern is received at the ninth stage 49 before reception of the calling code for the receiver 12 as exemplified in connection with Figure 3 ~F), it is unnecessary to carry Ollt the check of the message code part. The stage 52 therefore jumps back to the fifth stage 45 at which the first switching transistor 31 is now put in the above-mentioned on-of-f control-lable state. At first, the reception controller 21 switches the transistor 31 off. Subsequently, the reception controller 21 switches the transistor 31 conductive a little before the beginning of the first subframe sfl in a next following frame as indicated in Figure 3 (C) by the dashed line sfl'. The second switching transistor 32 is kept in the off state all the while.
If it is found at the eleventh stage 51 that the whole call code part is processed with neither the calling code for the receiver 12 nor the blank call pattern received in the first through the eighth call time slots Al to A8, it is also unnecessary to carry out the check. The twelfth stage 52 returns to the fifth stage 45.
If the calling code for the receiver 12 is received at the eighth stage 48, it is necessary to carry out the check irrespective of whether or not the detected calling code is followed by the blank call pattern. The reception controller 21 puts both the first and the second switching transistors 31 and 32 in on-off controllable states at a thirteenth stage 53. On the other hand, the reception controller 21 times the message code part with reference to the par-ticular call time slot ancl checks at a fourteenth stage 54 whether or not each message time slot corresponds to the particular call time slot. A little be-fore the leading edge of the corresponding message time slot, the reception controller 21 turns the first and the second switching transistors 31 and 32 6~
conductive as described with reference to Figures 3 ~D) and (E).
At fifteenth and sixteenth stages 55 and 56~ the display controller 28 checks if either a message code or the blank message pattern is present in the corresponding message time slot. If a message code is received at the fifteenth stage 55, the message is stored in the display memory at a seventeenth stage 57. If neither a message code nor the blank message pattern is received~
the call indication and the particular call time slot stored in the call memory, are cleared at an eighteenth stage 58.
After storage of the message in the displa.y memory at the seventeenth stage 57, the display controller 28 makes the reception controller 21 turn the first switching transistor 31 off while keeping the second switching transistor 32 in the on state as shown at anineteenth stage 59. If the blank message pattern is received at the sixteenth stage 56, the display controller 28 makes the reception controller 21 render both the first and the second switching transistors 31 and 32 off at the nineteenth stage 59. Also after clearance of the call memory at the eighteenth stage 58, the display controller 28 makes the reception controller 21 turn the both switching transistors 31 and 32 off at the nineteenth stage 59.
At a twentieth stage 60, the reception controller 21 checks if or not the message code part is already timed with reference to the Eirst through the eighth call time slots Al ~o A8. If already done, the reception controller 21 confirms at a twenty-first stage ~1 whether or not the first subframe has lapsed. It may be pointed out here that it is unnecessary for such timi.ng of the message code part and the subframe to supply the reproduction of the digital signal to the reception controller 21 from the waveform shaper 17.
The display controller 28 checks at a twenty-second stage 62 whether ~;~9~
or not the message is stored in the display memory. If present, the display controller 28 makes the reception controller 21 deliver the alert tone signal to the driver circuit 18 at a twenty-third stage 63 to make the loudspeaker 19 produce the call tone. At the same time, the display controller 28 makes the display unit 27 visually display the message. If the display memory is empty, the call memory is checked at a twenty-fourth stage 64 for the call indication.
If present, the alert tone is produced at a twen~cy-fifth stage 65.
If the receiver 12 has the automatic resetting function, the display controller 28 automatically clears the content of either the call memory and the display memory (stage 63) or the call memory ~stage 65) and stops either the alert tone and the visual display or the call tone. Concurrently, the dis-play controller 28 makes the reception controller 21 turn the first and the second switching transistors 31 and 32 off. The stage 63 or 65 j-umps back to the fifth stage 45, at which the first switching transistor 31 is again put in the on-off controllable state.
Attention will now be directed to the average current consumed in a pager receiver of the type described with reference to Figures 1 and 2. The current used in the reception controller 21 is about 0.01 mA. The to~al current used in the receiving circuit 16 and the waveform shaper 17 is about 4 mA. In-asmuch as the call to a pager receiver is only several times a day, it is pos-sible on calculating the average current to neglect the current used upon detec-tion of the call in the receiving circuit 16~ the waveform shaper 17, the driver circuit 18, the display unit 26, the programmable read-only memory 27, and the display controller 28. It will be surmised that the pager receivers of the paging system are divided into ten groups as described before.
For a conventional pager receiver referenced hereinabove, the saving 69tj4 ratio is 10 to 1. The average current is therefore:
(4 mA x 1 ~ 0.01 mA x 9)/10 = 0.409 mA.
For ~he pager receiver 12, the saving ratio is about 30 to 1. There-fore, the average current is:
(4 mA x 1 ~ 0.01 mA x 29)/30 = 0.143 mA.
It is understood that the power consumption is reduced to about 1/3.
If the pager receiver 12 is of the type thus far described with reference to Figures 1 through 4, the reduction to 1/3 is for the least favorable case in which the traffice is busiest to render the average current maximum. In the mostfavorable case in which the call seldom originates at the subscriber substationsfor the ac~ive pager receivers of the system, the saving ratio is about 120 to 1.
The average current is therefore:
~4 mA x 1 ~ 0.01 mA x 119)/120 = 0.0433 mA.
This shows that the power consumption is reduced to about 1/9. It will be appreciated that the power consumption is quite astonishingly reduced.
While this invention has so far been described in connection with a few preferred embodiments thereof, it will now readily be possible for one skilled in the art to carry this invention into effect in various other manners. For exam-ple, it is possible to use a different format rather than the format of the radio calling signal illustrated with reference to Figure 2. In this event, the flow chart described with reference to Figure 4 should accordingly be modified. Aboveall, codes or patterns different from the synchroniæing codes, the calling codes, the message codes, the blank call pattern, and the blank message pattern may be 9~4 placed between the synchronizing code and the call code part, between the call code part and the message code part, and/or after the message code part. In other words, the call time slots and the message time slots may be either con-tinuously or intermittently time sequentially arranged in each signal section, such as the first subframe sfl, which is intermittently time sequenced in the radio calling signal. Moreover, the pager receivers of each group may further be divided into a certain number of subgroups. In this latter event, each sub-frame of the radio calling signal should be divided into a plurality of smaller subgroups which are assigned to the respective subgroups. Such smaller sub-frames may also be called signal sections of the radio calling signal.
While carried by the user movable within a service area of a paging system and rendered active or operative, a pager receiver must always be ready for detecting a call which may reach that pager receiver at any time from a trans-mit~ing station of the system on a radio calling signal. The power for use in receiving the radio calling signal and indicating the call, is supplied from a battery carried by the receiver.
In order to reduce the power consumption in the receiver, it is cus-tomary to resort to a battery saving scheme as called for in tne art. According to the scheme, pager receivers of the paging system, either rendered active or kept inactive, are divided into a predetermined number of groups. Each frame of the radio calling signal is divided into a plurality of subframes which are allotted to the respective groups as will be described later. A conventional pager receiver for use in such a paging system comprises a receiver circuit for receiving the radio calling signal and for detecting a calling code pre-assigned to the receiver under consideration and an on-off control circuit for automatically energizing the receiver circuit only during the subframe allotted to the group which includes the receiver in question.
~n the other hand, it is a recent trend to make the radio calling signal include a message code which accompanies the calling code for a pager receiver and is representative of a message to be conveyed to that pager re-ceiver. An example of such a pager receiver is disclosed by Alfred B. Levine in United States Patent No. 4,336,524 which issued on May 12, 19~0. The subframe ~6~
becomes accordingly long. As will become clear as the description proceeds, it has now been found possible unexpectedly to save the battery in such a pager receivcr .
It is therefore a general object of the present invention to provide a pager receiver wllich is capable of receiving a message and in which the power consumption is reduced to a minimum.
It is a specific object of this invention to provide a pager receiver of the type described, in which the power consumption is further reduced when the traffic is not busy.
According to this invention, there is provided a pager receiver com-prising first through fourth means as follows.
The first means is for receiving a radio calling signal comprising a call code part and a message code part. The call code part has a preselected number of call time slots. The message code part has a plurality of message time slots which correspond to the call time slots, respectively. The call time slots and the message time slots are time sequentially arranged.
The second means is coupled to the first means for detecting a calling code preassigned to the pager receiver and for deciding which one call time slot of the call time slots contains the calling code detected.
The third means is coupled to the first means through the second means for detecting either of a message code and a blank message pattern in one message time slot of the message time slots that corresponds to the afore-mentioned one call time slotO
The fourth means is responsive to the above-described one call time slot for energizing the first and the third means substantially at a leading edge of the above-mentioned one message time slot.
6 ~
Brief Description of the Drawing:
Figure l is a block diagram showing a transmitting station together with a pager receiver according to a preferred embodiment of the instant inven-tion;
~ igure 2 exemplifies the format of a radio calling signal which is to be received by the pager receiver illustrated in Figure l;
Figure 3 is a schematic time chart for use in describing the operation of the pager receiver of Figure l; and Figures 4(a) and 4(b) together constitute a flow chart for use in de-scribing the operation of the pager of the invention.
Referring to Figure l, a paging system comprises a transmitting station ll having a certain service area. The system further comprises a plurality of pager receivers. Most of the pager receivers are rendered active or operative within the service area during the business hours. Usually, only a few of the pager receivers are kept active in the midnight hours. At any rate, the pager receivers of the system are divided into a predetermined number of groups as described heretobefore. By way of example, let the groups be numbered one through ten groups. One of the pager receivers of the first group is depicted at 12 ~Figure 1) as a representative of the pager receivers of the system.
A plurality of subscriber substations (not shown) are connected to the transmitting station 11. When a call to a desired one of the active pager re-ceivers of the system originates at one of the subscriber subs~ations, the call is transmitted by the transmitting station 11 over the service area on a radio calling signal. It will be assumed that the calling signal is an FM ~frequency modulated) signal.
Turning to Figure 2, each frame of ~he radio calling signal is divided ~6~
into first through tenth subframes sfl to sflO which are allotted to the first through the tenth groups, respectively. As illustrated in detail for the first subframe sfl, each subframe comprises a synchronizing code or word, such as S, a call code part after the synchronizing code, and a message code part after the call code part.
The synchronizing codes have those patterns of binary one and zero bits which are unique to the respective subframes. The pager receivers, such as 12 ~Figure 1), of each group are responsive to the synchronizing code of the subframe which is allotted to that group.
The call code part has a preselected number of time sequentially arranged call time slots or intervals. In the example being illustrated, the call code part of the first subframe sfl immediately follows the synchronizing code S and consists of first through eighth call time slots Al to A8. The message code part immediately follows the call code part and consists of first through eighth message time slots or durations Dl to D8 which are in one-to-one correspondence to the first through the eighth call time slots Al to A8.
In the manner known in the art, the transmitting station 11 (Figure 1) sends a calling code or word in one of the call time slots of one of the sub-frames sfl through sflO in response to a call which originates at a subscriber substation for a desired one of the active pager receivers of the system that is movable within the service area. Such calling codes are preassigned to the re-spective pager receivers, active or inactive, of each group. In order so to preassign, each calling code consists of a prescribed number of binary one and zero bits.
The call may or may not be accompanied by a message to be conveyed to the desired pager receiver. In the presence of a message. the transmitting 6~4 station 11 sends a message code or word in one of the message time slots of the subframe under consideration that corresponds to the call time slot at which the calling code for the desired pager receiver is placed. The message code consists of a certain number of binary one and zero bits which are arranged to represent the message. It is to be noted here that the message, as herein called, should be understood in the broadest sense of the word and may be in-dicative of control of the desired pager receiver.
It is more preferred, when the calling code or codes actually sent in a subframe is less in number than the call time slots of that subframe, that the calling code be placed according to the so-called first-in first-out scheme in each call time slot which is nearer to the synchronizing code, namely, to a leading edge of the call code part and that a blank call pattern be placed in each call time slot at which no calling code is present. For instance, the calling code for the receiver 12 is in the fourth call time slot A~ if sent by the transmitting station 11 in response to a call which originates after the beginning of one frame as a fourth, an eighty-fourth (assuming eight call time slots in each subframe)l or a like one of the calls for the pager receivers of the first group. The blank call pattern should consist of binary one and zero bits arranged in a pattern which is not used as the calling codes for the pager receivers of the group in question. Most preferably, the blank call pattern should consist of b;nary one and zero bits which are arranged as random as pos-sible. Similarly, a blank message pattern is placed at a message time slot at which no message code is present.
Referring back to Figure 1, the pager receiver 12 comprises an antenna 15 for receiving the radio calling signal. An ordinary FM receiving circuit 16 is included for subjecting the received calling signal to frequency conversion~
6~
amplification~ and demodulation. The receiving circuit 16 comprises a discri-minator (not shown~ which produces the demoduated calling signal. A waveform shaper 17 is for shaping the waveform of the demodulated calling signal to pro-duce a reproduction of a digital signal which is produced in the transmitting station 11 to be transmitted as the radio calling signal. Responsive to an alert tone signal which will presently be described~ a driver circuit 18 makes a loudspeaker 19 produce an alert tone. The receiving circuit 16, the waveform shaper 17, and the driver circuit 18 are known in the art. For in-stance, the receiving circuit 16 may be of the type described in United States patent No. 4,194,153, issued on September 14, 1978 to Masaru Masaki et al and and assigned to Nippon Electric Co., Ltd., one of the present assignees. The waveform shaper 17 may be of the structure comprising a low-pass filter and a comparator.
A reception controller 21 is provided for generating a clock pulse sequence and for establishing bit synchronism of the clock pulses. The recep-tion controller 21 is coupled to the waveform shaper 17 so as to detect the synchronizing code S of the first subframe sfl ~igure 2) to provide a reference for use in timing the first through the eighth call time slots Al to A8 and the first through the eighth message time slots Dl to D8. The reception controller 21 is furthermore for timing the call code part~ for detecting the calling code preassigned to the receiver 12 in the first subframe sfl, for deciding that one of the call time slots Al through A8 as a particular call time slot at which the calling code is detected, for producing the alert tone signal as will later be described, and for producing a first and a second control signal which will shortly be described. The reception controller 21 comprises a call memory (not shown) in which a call indication indicative of detection of the calling code ~69~
and the particular call time slot are stored. It is possible to implement most of the reception controller 21 by a large-scale integrated semiconductor circuit ~LSI).
When a switch 22 is closed to render the receiver 12 active, the re-ception controller 21 is supplied with the power from a battery 23 carried by the receiver 12. The power is supplied also ~o the driver circuit 18. The driver circuit 18, however, does not consume the power unless the alert tone signal is delivered thereto from the reception controller 21.
A display unit 26 is provided for visually displaying a message con-veyed to the receiver 12 as a message code at one of the message time slots Dl through D8 that corresponds to the particular call time slot~ When the message is represented only by numerals, the message unit 26 may be a twelve-digit seven-segment liquid crystal display. When the message is alphanumeric, the display unit 26 may comprise a five-by-seven-dot matrix liquid crystal display.
A programmable read-only memory (P-ROM) 27 is for memorizing the call code preassigned to the receiver 12. It may be mentioned here that the receiver 12 may receive a message code and display a translation of the message code as the message according to the key code scheme as called in the art.
In this event, a table for the translation is memorized in the read-only memory 27. Furthermore, -the read-only memory 27 is for memorizing various modes of operation of the receiver 12. For example~ the receiver 12 may be given a function of automatically xesetting the alert tone and the displayed message.
It is also possible ~o render the receiver 12 so as not to respond to the mes-sage code part of the first subframe sfl of the received calling signal. Under the circumstances, the modes of operation are memorized in the read-only memory 27.
A display controller 28 is a one-chip central processing unit coupled to the reception controller 21, the display unit 26, and the read-only memory Z7.
A program for putting the receiver 12 into operationJ is memorized in the dis-play controller 28. Subroutines of the program may be memorized in the read-only memory 27. As will later be described more in detail, the display con-troller 28 reads the calling code from the read-only memory 27 to supply the read-out calling code to the reception controller 21. After timing of the call code part, the reception controller 21 times the message code part. At a mes-sage time slot corresponding to the particular call time slot, the display con-troller 28 is energized, together with the receiving circuit 16 and the wave-form shaper 17, to detect a message code and subject the same to error correc-tion. The display controller 28 comprises a display memory (not shown) for / storing the message which is represented by the error corrected message code or, as the case may be, given by the translation of the error corrected message code.
The display controller 28 delivers the message to the display unit 26 for a visual display as will later be described.
The power is supplied to the receiving circuit 16 and the waveform shaper 17 through a first switching transistor 31, which is controlled by the first control signal. The power is supplied to the display unit 26, the read-only memory 27, and the display controller 28 through a second switching tran-sistor 32 controlled by the second control signal.
Referring furthermore to Figure 3, the calling codes preassigned to eight pager receivers of the first group are present in the -first through the eighth call time slots Al to A8 of the first subframe sfl when the traffic is busiest. It may be that none of the calling codes is for the illustrated pager receiver 12 as indicated in Figure 3 (A) by srosses. Alternatively, the calling code preassigned in the first subframe sfl to the receiver 12 may be present in one of the call time slots Al through A8 together with a message code in the message code part. By way of example, let the calling code for the receiver 12 be present in the fourth call time slot A4 as represented in Figure 3 (B) by a circle 35. The message code under consideration is placed in the fourth message time slot D4 as shown by another circle 36. When the reception controller 21 fails to detect the calling code for the receiver 12 as exemplified in Figure 3 (A), the reception controller 21 makes the first control signal turn the first switching transistor 31 off or nonconductive at the end of the call code part as will presently be described more in detail.
As illustrated in Figure 3 ~C), the reception controller 21 makes the first control signal render the first switching transistor 31 on or conductive when synchronism of the clock pulse sequence is established after closure of the switch 22. When the reception controller 21 detects the synchroni~ing code S
of the first subframe sfl, the reception controller 21 makes the first control signal keep the first switching ~ransistor 31 in the on state. At the fourth call time slot A4, the reception controller 21 detects the calling code which is preassigned to the receiver 12 and is depicted by a hatched area 37. The re-ception controller 21 continues timing of the call code part and makes the first control signal turn the first switching tr~msistor 31 off at the end of the call code part. The reception controller 21 further times the message code part and makes the first control signal turn the first switching transistor 31 again con-ductive substantially during ~he fourth message time slot D4.
As shown in Figures 3 (D) and (E), the reception controller 21 makes the second control signal keep the second switching transistor 32 in the off state at first. The reception controller 21 makes the second control signal ~ ' _ 9 :, , turn the second switching transistor 32 conductive substantially at a ]eading edge of the fourth message time slot D4. If the display controller 28 detects a message code illustrated by another hatched area 38 at the fourth message time slot D4, the reception controller 21 responds to the detection and makes the second control signal keep the second switching transistor 32 in the on state. If the display controller 28 detects a blank message pattern depicted by still another hatched area 39 at the fourth message time slot D4, the re-ception ccntroller 21 responds to the detection and makes the second control signal turn the second switching transistor 32 off substantially at a trailing edge of the fourth message time slot D4.
It is now understood that the pager receiver 12 comprises a receiver part 15, 16, and 17 for receiving the radio calling signal, a reception con-troller 21 coupled to the receiver part for detecting a calling code preassigned to the receiver 12 and for deciding that one call time slot of the call time slots contains the calling code detected, a display part 26, 27, and 28 coupled to the receiver part through the reception controller 21 for detecting either of a message code and a blank message pattern in one message time slot of the message time slots that corresponds to the afore-mentioned one call time slot, and switching transistors 31 and 32 responsive to the above-described one call time slot for energizing the receiver part and the display part substantially at a leading edge of the above-mentioned one message time slot.
As described before, it is preferred that the calling code be placed in less mlmbered call time slot and that the blank call pattern be placed in each call time slot at which no calling code is present. In this event, the blank call pattern may be memori~ed in the reception controller 21. When the traffic is not busy, an appreciable number of the blank call patterns may be 969~
presen~ in the call code part of a subframe. Depending on the circurnstances~
the blank call pattern is placed even in the first call time slot Al as indi-cated in Figure 3 (F) by a triangle.
As soon as the reception controller 21 detects the blank call pattern in any one of the call time slots Al through A8, the reception controller 21 makes the first control signal turn the first switching translstor 31 off as exemplified in Figure 3 ~F). The reception controller 21 subsequently makes the first control signal turn the first switching transistor 31 conductive substan-tially at a leading edge of a next following first subframe sfl as indicated in Figure 3 ~C) by a dashed line sfl' while making the second control signal keep the second switching transistor 32 in the off state.
Referring additionally to Figure 4, it will be presumed that the pager receiver 12 is operable in response to a radio calling signal according to the more pre~erred aspect of this invention and that the switch 22 is closed at a first stage 41 to put the receiver 12 into operation. The reception controller 21 is energized to turn the first switching transistor 31 instantaneously on as indicated at a second stage 42 while beginning to generate the clock pulse se-quence. It is preferred that the reception controller 21 momentarily render the second switching transistor 32 also on to make the display controller 28 transfer the calling code for the receiver 12 and the blank call pattern to a memory in the reception controller 21 from the read-only memory 27. The second switching transistor 32 is kept in the off state until an instant which will later be described.
As illustrated at a third stage 43, synchroni7ation of the clock pulse sequence is carried out. Establishment of the synchronism is checked at a fourth stage 44. If not, the stage 44 returns to the second stage 42. If the synchronism is established, the reception controller 21 tu~ns the first switch-ing transistor 31 again on at a fifth stage 45. Except for an on-off control of the first switching transistor 31 to be presently described and operation of the second switching transistor 32~ the stages 41 through 45 are known in the art.
The reception controller 21 searches for the synchronizing code S of the first subframe sfl at a sixth stage 46. If the synchronizing code S is re-ceived~ the reception controller 21 is put in a state for checking the call time slots Al through A8 one by one as will shortly be described. Even though the synchronizing code S is not detected, the reception controller 21 remains in this state insofar as the synchronism is maintained as shown at a seventh stage 47. After lapse of a certain duration, the synchronism may go out of order.
In this event~ the stage 47 returns to the second stage 42.
While checking each call time slot, the reception controller 21 may find either the calling code for the receiver 12 at an eighth stage 48 or the blank call pattern at a ninth stage 49. If the calling code is received, the reception controller 21 makes the call memory thereof store, as indicated at a tenth stage 50, a call indication indicative of the reception and a particular call time slot at which the calling code is received.
If the received callin~ code is not followed by the blank call pattern as in the busiest hours of the traffic3 the reception controller 21 checks at an eleventh stage 51 whether or not the whole call code part is already dealt with. If not, the search for the calling code and the blank call pattern is repeated. Either upon reception of the blank call pattern or upon completion of the processes for the whole call code part, the stage 49 or 51 proceeds for-ward to a twelfth stage 52 at which decision is carried out as regards necessity and unnecessity of checking the message code part for a message code and the 96~6~
blank message pattern as will shortly be described.
If the blank call pattern is received at the ninth stage 49 before reception of the calling code for the receiver 12 as exemplified in connection with Figure 3 ~F), it is unnecessary to carry Ollt the check of the message code part. The stage 52 therefore jumps back to the fifth stage 45 at which the first switching transistor 31 is now put in the above-mentioned on-of-f control-lable state. At first, the reception controller 21 switches the transistor 31 off. Subsequently, the reception controller 21 switches the transistor 31 conductive a little before the beginning of the first subframe sfl in a next following frame as indicated in Figure 3 (C) by the dashed line sfl'. The second switching transistor 32 is kept in the off state all the while.
If it is found at the eleventh stage 51 that the whole call code part is processed with neither the calling code for the receiver 12 nor the blank call pattern received in the first through the eighth call time slots Al to A8, it is also unnecessary to carry out the check. The twelfth stage 52 returns to the fifth stage 45.
If the calling code for the receiver 12 is received at the eighth stage 48, it is necessary to carry out the check irrespective of whether or not the detected calling code is followed by the blank call pattern. The reception controller 21 puts both the first and the second switching transistors 31 and 32 in on-off controllable states at a thirteenth stage 53. On the other hand, the reception controller 21 times the message code part with reference to the par-ticular call time slot ancl checks at a fourteenth stage 54 whether or not each message time slot corresponds to the particular call time slot. A little be-fore the leading edge of the corresponding message time slot, the reception controller 21 turns the first and the second switching transistors 31 and 32 6~
conductive as described with reference to Figures 3 ~D) and (E).
At fifteenth and sixteenth stages 55 and 56~ the display controller 28 checks if either a message code or the blank message pattern is present in the corresponding message time slot. If a message code is received at the fifteenth stage 55, the message is stored in the display memory at a seventeenth stage 57. If neither a message code nor the blank message pattern is received~
the call indication and the particular call time slot stored in the call memory, are cleared at an eighteenth stage 58.
After storage of the message in the displa.y memory at the seventeenth stage 57, the display controller 28 makes the reception controller 21 turn the first switching transistor 31 off while keeping the second switching transistor 32 in the on state as shown at anineteenth stage 59. If the blank message pattern is received at the sixteenth stage 56, the display controller 28 makes the reception controller 21 render both the first and the second switching transistors 31 and 32 off at the nineteenth stage 59. Also after clearance of the call memory at the eighteenth stage 58, the display controller 28 makes the reception controller 21 turn the both switching transistors 31 and 32 off at the nineteenth stage 59.
At a twentieth stage 60, the reception controller 21 checks if or not the message code part is already timed with reference to the Eirst through the eighth call time slots Al ~o A8. If already done, the reception controller 21 confirms at a twenty-first stage ~1 whether or not the first subframe has lapsed. It may be pointed out here that it is unnecessary for such timi.ng of the message code part and the subframe to supply the reproduction of the digital signal to the reception controller 21 from the waveform shaper 17.
The display controller 28 checks at a twenty-second stage 62 whether ~;~9~
or not the message is stored in the display memory. If present, the display controller 28 makes the reception controller 21 deliver the alert tone signal to the driver circuit 18 at a twenty-third stage 63 to make the loudspeaker 19 produce the call tone. At the same time, the display controller 28 makes the display unit 27 visually display the message. If the display memory is empty, the call memory is checked at a twenty-fourth stage 64 for the call indication.
If present, the alert tone is produced at a twen~cy-fifth stage 65.
If the receiver 12 has the automatic resetting function, the display controller 28 automatically clears the content of either the call memory and the display memory (stage 63) or the call memory ~stage 65) and stops either the alert tone and the visual display or the call tone. Concurrently, the dis-play controller 28 makes the reception controller 21 turn the first and the second switching transistors 31 and 32 off. The stage 63 or 65 j-umps back to the fifth stage 45, at which the first switching transistor 31 is again put in the on-off controllable state.
Attention will now be directed to the average current consumed in a pager receiver of the type described with reference to Figures 1 and 2. The current used in the reception controller 21 is about 0.01 mA. The to~al current used in the receiving circuit 16 and the waveform shaper 17 is about 4 mA. In-asmuch as the call to a pager receiver is only several times a day, it is pos-sible on calculating the average current to neglect the current used upon detec-tion of the call in the receiving circuit 16~ the waveform shaper 17, the driver circuit 18, the display unit 26, the programmable read-only memory 27, and the display controller 28. It will be surmised that the pager receivers of the paging system are divided into ten groups as described before.
For a conventional pager receiver referenced hereinabove, the saving 69tj4 ratio is 10 to 1. The average current is therefore:
(4 mA x 1 ~ 0.01 mA x 9)/10 = 0.409 mA.
For ~he pager receiver 12, the saving ratio is about 30 to 1. There-fore, the average current is:
(4 mA x 1 ~ 0.01 mA x 29)/30 = 0.143 mA.
It is understood that the power consumption is reduced to about 1/3.
If the pager receiver 12 is of the type thus far described with reference to Figures 1 through 4, the reduction to 1/3 is for the least favorable case in which the traffice is busiest to render the average current maximum. In the mostfavorable case in which the call seldom originates at the subscriber substationsfor the ac~ive pager receivers of the system, the saving ratio is about 120 to 1.
The average current is therefore:
~4 mA x 1 ~ 0.01 mA x 119)/120 = 0.0433 mA.
This shows that the power consumption is reduced to about 1/9. It will be appreciated that the power consumption is quite astonishingly reduced.
While this invention has so far been described in connection with a few preferred embodiments thereof, it will now readily be possible for one skilled in the art to carry this invention into effect in various other manners. For exam-ple, it is possible to use a different format rather than the format of the radio calling signal illustrated with reference to Figure 2. In this event, the flow chart described with reference to Figure 4 should accordingly be modified. Aboveall, codes or patterns different from the synchroniæing codes, the calling codes, the message codes, the blank call pattern, and the blank message pattern may be 9~4 placed between the synchronizing code and the call code part, between the call code part and the message code part, and/or after the message code part. In other words, the call time slots and the message time slots may be either con-tinuously or intermittently time sequentially arranged in each signal section, such as the first subframe sfl, which is intermittently time sequenced in the radio calling signal. Moreover, the pager receivers of each group may further be divided into a certain number of subgroups. In this latter event, each sub-frame of the radio calling signal should be divided into a plurality of smaller subgroups which are assigned to the respective subgroups. Such smaller sub-frames may also be called signal sections of the radio calling signal.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A pager receiver comprising:
first means for receiving a radio calling signal comprising a call code part and a message code part, said call code part having a preselected number of call time slots, said message code part having a plurality of message time slots corresponding to said call time slots, respectively, said call time slots and said message time slots being time sequentially arranged;
second means coupled to said first means for detecting a calling code preassigned to said pager receiver and for deciding which one call time slot of said call time slots contains the calling code detected;
third means coupled to said first means through said second means for detecting either of a message code and a blank message pattern in one message time slot of said message time slots that corresponds to said one call time slot; and fourth means responsive to said one call time slot for energizing said first and said third means substantially at a leading edge of said one message time slot.
first means for receiving a radio calling signal comprising a call code part and a message code part, said call code part having a preselected number of call time slots, said message code part having a plurality of message time slots corresponding to said call time slots, respectively, said call time slots and said message time slots being time sequentially arranged;
second means coupled to said first means for detecting a calling code preassigned to said pager receiver and for deciding which one call time slot of said call time slots contains the calling code detected;
third means coupled to said first means through said second means for detecting either of a message code and a blank message pattern in one message time slot of said message time slots that corresponds to said one call time slot; and fourth means responsive to said one call time slot for energizing said first and said third means substantially at a leading edge of said one message time slot.
2. A pager receiver as claimed in Claim 1, wherein said fourth means con-tinuously energizes said first and said third means until lapse of said message code part when a message code is detected in said one message time slot, said fourth means deenergizing said first and said third means substantially at a trailing edge of said one message time slot when said blank message pattern is detected in said one message time slot.
3. A pager receiver as claimed in Claims 1 or 2, said radio calling sig-nal being a sequence of signal sections, each signal section comprising said call code part and said message code part, a calling code being placed in each call time slot which is nearer to a leading edge of each signal section, a blank call pattern being placed in each call time slot in which no calling code is present, wherein:
said second means is for furthermore detecting said blank call pattern;
said fourth means being furthermore responsive to the blank call pattern detected by said second means for deenergizing and energizing said first means, said fourth means deenergizing said first means substantially at a trail-ing edge of the call time slot in which said blank call pattern is detected, said fourth means energizing said first means substantially at the leading edge of the signal section next following the signal section in which said blank call pattern is detected.
said second means is for furthermore detecting said blank call pattern;
said fourth means being furthermore responsive to the blank call pattern detected by said second means for deenergizing and energizing said first means, said fourth means deenergizing said first means substantially at a trail-ing edge of the call time slot in which said blank call pattern is detected, said fourth means energizing said first means substantially at the leading edge of the signal section next following the signal section in which said blank call pattern is detected.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57007809A JPS58124338A (en) | 1982-01-20 | 1982-01-20 | Selective calling communication system |
| JP7809/1982 | 1982-01-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1196964A true CA1196964A (en) | 1985-11-19 |
Family
ID=11675932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000419817A Expired CA1196964A (en) | 1982-01-20 | 1983-01-19 | Pager receiver comprising a message detector energized only at pertinent time slots |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4668949A (en) |
| JP (1) | JPS58124338A (en) |
| KR (1) | KR860001455B1 (en) |
| AU (1) | AU555154B2 (en) |
| CA (1) | CA1196964A (en) |
| GB (1) | GB2114343B (en) |
| HK (1) | HK52488A (en) |
| SG (1) | SG20388G (en) |
Families Citing this family (57)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE444870B (en) * | 1984-09-17 | 1986-05-12 | Tateco Ab | PROCEDURE OF TRANSMISSION IN A PERSONAL SUBSYSTEM |
| ATE61705T1 (en) | 1984-12-05 | 1991-03-15 | Ate Corp | PERSONAL CALL SYSTEM AND COMMUNICATION PROTOCOL. |
| US5150954A (en) * | 1984-12-05 | 1992-09-29 | Seiko Corporation | Pager watch system utilizing time slot communication |
| JPH06101700B2 (en) * | 1986-05-15 | 1994-12-12 | 株式会社東芝 | Battery saving method |
| US4853674A (en) * | 1986-07-21 | 1989-08-01 | Kiss Michael Z | Signalling apparatus for hearing impaired persons |
| US5189409A (en) * | 1987-04-25 | 1993-02-23 | Sharp Kabushiki Kaisha | System for controlling terminal equipment |
| IL85558A (en) * | 1987-04-30 | 1992-01-15 | Motorola Inc | Personal message receiving device with separate information presentation means |
| JPH01141423A (en) * | 1987-11-28 | 1989-06-02 | Toshiba Corp | Selective call system |
| US5274843A (en) * | 1987-11-28 | 1993-12-28 | Kabushiki Kaisha Toshiba | Paging apparatus having a battery saving function |
| JP2581719B2 (en) * | 1987-12-25 | 1997-02-12 | 日本電信電話株式会社 | Selective call communication method |
| US4928274A (en) * | 1988-01-19 | 1990-05-22 | Qualcomm, Inc. | Multiplexed address control in a TDM communication system |
| AU3347089A (en) * | 1988-02-29 | 1989-09-22 | Motorola, Inc. | Acknowledge back paging system having the capability of matching data messages to pager addresses |
| US4860003A (en) * | 1988-05-27 | 1989-08-22 | Motorola, Inc. | Communication system having a packet structure field |
| US5187471A (en) * | 1988-06-24 | 1993-02-16 | Kabushiki Kaisha Toshiba | Radio telecommunication apparatus |
| JPH0226137A (en) * | 1988-07-15 | 1990-01-29 | Nippon Telegr & Teleph Corp <Ntt> | Radio calling receiver |
| JPH0616601B2 (en) * | 1988-09-07 | 1994-03-02 | 三洋電機株式会社 | Power save circuit of received radio wave processing circuit and power save method thereof |
| US5150361A (en) * | 1989-01-23 | 1992-09-22 | Motorola, Inc. | Energy saving protocol for a TDM radio |
| US5086501A (en) * | 1989-04-17 | 1992-02-04 | Motorola, Inc. | Computing system with selective operating voltage and bus speed |
| US5032835A (en) * | 1989-04-24 | 1991-07-16 | Motorola, Inc. | Out of range indication for radio receivers |
| US5089813A (en) * | 1989-07-19 | 1992-02-18 | Motorola, Inc. | Method of super battery saving in a selective call receiver |
| WO1991003037A1 (en) * | 1989-08-21 | 1991-03-07 | Motorola, Inc. | Selective call signalling system |
| US5450071A (en) * | 1989-08-21 | 1995-09-12 | Motorola, Inc. | Method and apparatus for addressing a single message to multiple addresses |
| WO1991006189A1 (en) * | 1989-10-17 | 1991-05-02 | At&E Corporation | Radio receiver with adaptive on-off control |
| US5155479A (en) * | 1989-10-17 | 1992-10-13 | Seiko Corp. | Radio receiver with adaptive on-off control |
| US5257019A (en) * | 1989-11-03 | 1993-10-26 | Motorola, Inc. | Satellite selective call signalling system |
| JP3190030B2 (en) * | 1990-03-19 | 2001-07-16 | 日本電信電話株式会社 | Intermittent reception method in mobile communication |
| SG43201A1 (en) * | 1991-02-14 | 1997-10-17 | Nec Corp | Radio pager with power-backup memory for storing uncompleted messages |
| JP2712868B2 (en) * | 1991-03-30 | 1998-02-16 | 日本電気株式会社 | Selective call receiver |
| US5555183A (en) * | 1991-12-02 | 1996-09-10 | Motorola, Inc | Method and apparatus for synchronizing to a synchronous selective call signal |
| US5325088A (en) * | 1991-12-02 | 1994-06-28 | Motorola, Inc. | Synchronous selective signalling system |
| US5384564A (en) * | 1992-01-23 | 1995-01-24 | Keith H. Wycoff | Battery saving arrangement for selectively addressable, portable receivers |
| FR2690029B1 (en) * | 1992-04-08 | 1995-03-31 | France Telecom | Method for transmitting digital paging data, and corresponding paging receiver. |
| US5635914A (en) * | 1992-05-29 | 1997-06-03 | Motorola, Inc. | Method and apparatus for dynamic group calling in a selective call system |
| US5493282A (en) * | 1992-05-29 | 1996-02-20 | Motorola, Inc. | Addressing method for conserving power in distributed information receivers |
| US5311516A (en) * | 1992-05-29 | 1994-05-10 | Motorola, Inc. | Paging system using message fragmentation to redistribute traffic |
| EP0597064B1 (en) * | 1992-05-29 | 2001-10-04 | Motorola, Inc. | Data communication receiver having variable length message carry-on |
| EP0639898B1 (en) * | 1993-01-28 | 2003-04-02 | NTT DoCoMo, Inc. | Wireless call system |
| US5835023A (en) * | 1993-02-25 | 1998-11-10 | Ntt Mobile Communications Network Inc. | Selective radio paging system and pager |
| US5423057A (en) * | 1993-10-01 | 1995-06-06 | Motorola, Inc. | Method and apparatus for sharing signaling formats in a communication channel |
| US5440299A (en) * | 1993-10-01 | 1995-08-08 | Motorola, Inc. | Method and apparatus for equalizing battery life in a selective call communication system |
| JP2643802B2 (en) * | 1993-10-15 | 1997-08-20 | 日本電気株式会社 | Selective call receiver |
| FR2711865B1 (en) * | 1993-10-26 | 1995-12-01 | Alcatel Mobile Comm France | Signaling and control methods used in a radio communication system, base station and mobile station for the implementation of these methods. |
| US5481254A (en) * | 1993-11-02 | 1996-01-02 | Seiko Communications Holding N.V. | Group message delivery in a time-division multiplexed paging system |
| US5475374A (en) * | 1994-01-31 | 1995-12-12 | Motorola, Inc. | Method and apparatus for energy conservation in a communication system |
| JP2658891B2 (en) * | 1994-07-15 | 1997-09-30 | 日本電気株式会社 | Selective calling system and receiving method thereof |
| US5649315A (en) * | 1995-09-21 | 1997-07-15 | Motorola, Inc. | Method for selecting between first, second and third battery saving periods in a selective call |
| US5550829A (en) * | 1995-10-24 | 1996-08-27 | Motorola, Inc. | Method for reallocation frame assignments of receives in a communication system |
| US5930706A (en) * | 1995-11-29 | 1999-07-27 | Ericsson Inc. | Detecting messages transmitted over a communications channel such as a paging channel |
| US7590083B2 (en) | 1995-12-07 | 2009-09-15 | Transcore Link Logistics Corp. | Wireless packet data distributed communications system |
| JP2982948B2 (en) * | 1995-12-27 | 1999-11-29 | 松下電器産業株式会社 | Wireless receiver |
| JP2885722B2 (en) * | 1996-09-17 | 1999-04-26 | 静岡日本電気株式会社 | Radio selective call receiver |
| KR19980068328A (en) * | 1997-02-18 | 1998-10-15 | 김광호 | Vibration method in phaser |
| JPH10304031A (en) * | 1997-04-25 | 1998-11-13 | Nec Corp | Portable radio communication equipment |
| US6950684B2 (en) | 2002-05-01 | 2005-09-27 | Interdigital Technology Corporation | Method and system for optimizing power resources in wireless devices |
| CN1653733B (en) | 2002-05-06 | 2011-07-06 | 美商内数位科技公司 | Method used in wireless transmitting or receiving unit |
| US20060141961A1 (en) * | 2004-12-23 | 2006-06-29 | Schentrup Philip A | Method and system for selective receiver shutdown |
| JP4726122B2 (en) * | 2005-09-20 | 2011-07-20 | 能美防災株式会社 | Terminal in transmission system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4417246A (en) * | 1979-11-19 | 1983-11-22 | General Electric Company | Paging receiver having a serial code plug |
| JPS56136050A (en) * | 1980-03-28 | 1981-10-23 | Nec Corp | Individual selective call reception system |
| JPS5792932A (en) * | 1980-12-01 | 1982-06-09 | Nec Corp | Selective calling receiver with display |
-
1982
- 1982-01-20 JP JP57007809A patent/JPS58124338A/en active Granted
-
1983
- 1983-01-19 AU AU10605/83A patent/AU555154B2/en not_active Ceased
- 1983-01-19 CA CA000419817A patent/CA1196964A/en not_active Expired
- 1983-01-20 KR KR1019830000210A patent/KR860001455B1/en not_active IP Right Cessation
- 1983-01-20 GB GB08301533A patent/GB2114343B/en not_active Expired
-
1986
- 1986-02-26 US US06/834,130 patent/US4668949A/en not_active Expired - Lifetime
-
1988
- 1988-03-28 SG SG203/88A patent/SG20388G/en unknown
- 1988-07-14 HK HK524/88A patent/HK52488A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2114343B (en) | 1985-08-14 |
| AU555154B2 (en) | 1986-09-11 |
| KR860001455B1 (en) | 1986-09-25 |
| HK52488A (en) | 1988-07-22 |
| AU1060583A (en) | 1983-07-28 |
| JPS58124338A (en) | 1983-07-23 |
| JPH0412052B2 (en) | 1992-03-03 |
| US4668949A (en) | 1987-05-26 |
| KR840003560A (en) | 1984-09-08 |
| GB2114343A (en) | 1983-08-17 |
| GB8301533D0 (en) | 1983-02-23 |
| SG20388G (en) | 1988-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1196964A (en) | Pager receiver comprising a message detector energized only at pertinent time slots | |
| US5230084A (en) | Selective call receiver having extended battery saving capability | |
| US6078631A (en) | Wireless communication system compulsively turning remote terminals into inactive state | |
| CA2083946C (en) | Battery saving method and apparatus for providing selective receiver power switching | |
| JP3110173B2 (en) | Reception control method of radio selective calling receiver | |
| US5459457A (en) | Paging or other selective call system with battery power conservation | |
| US5697097A (en) | Method for increasing the endurance of an information receiver, particularly for radio paging, and corresponding receiver | |
| RU2178238C2 (en) | Discriminating-call system and its secondary station | |
| CA1217821A (en) | Paging receiver having a plurality of test modes | |
| US5487090A (en) | Selectively called radio receiver in which bit rate detection is controlled with a predetermined range | |
| US6216385B1 (en) | Radio calling receiver with means to control reception based on service area, time zone, and/or electric field strength | |
| EP0413963B1 (en) | Radio communication apparatus for rapidly knowing whether the apparatus is within or out of a service area | |
| KR950011078B1 (en) | Selective calling system | |
| WO1993022848A1 (en) | Adaptative battery saving controller | |
| EP0649209B1 (en) | Power supply control for a receiver | |
| EP0872042B1 (en) | Apparatus for delivering global event information in a radio communication system | |
| GB2121575A (en) | Pager receiver | |
| JPH04304043A (en) | Radio selective call receiver | |
| JP2734990B2 (en) | Radio selective call receiver | |
| JP2935037B2 (en) | Call detection device | |
| EP0726684B1 (en) | Intermittent receiving control apparatus of a selective calling receiver and corresponding method | |
| JPH0226137A (en) | Radio calling receiver | |
| EP0717573A2 (en) | Power sarring function for a radio paging receiver | |
| JPS60170343A (en) | Selectively called receiving device | |
| JP3006150B2 (en) | Selective call receiver |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20030119 |