Paging method and apparatus

The present invention relates to communication paging. Specifically, for bidirectional paging methods and devices Related.

Over the last few decades, pagers have been heavy on getting in touch with remote people. It turned out to be an important communication device. Early pagers were primarily audio and / or vibrating It supplied only power, but more recent pagers have, for example, alphanumeric characters containing messages. The output capacity like a spray is strengthened.

The paging system has conventionally been a one-way system. That is, the user is the central terminal Receives a paging message from, but uses a pager to respond to the message. There was no way. A prior art attempt to provide two-way communication capabilities for pagers This includes efforts to connect the pager to a telephone (eg, a mobile radiotelephone). There was. For example, U.S. Pat. No. RE33,417 granted to Bhagat et al. (Wireless page) By linking the entire system with the radiotelephone through an automatic dialer) and US Pat. No. 5,117,449 (Paging and Cellular) granted to Metroka et al. (It is said that the radiotelephone function is combined in a single unit).

<p> Some pagers also have the ability to acknowledge or respond to paging signals. Some are. In such an "acback" system, the user is charged. There is a response input device (for example, toggle switch, push button switch) when it is used. Or operate the keyboard). Typically, such an acback system has a large number. It involves a complex acknowledge transmission scheme with frequency or multiple frequency subbands. A pager is a different geographic area managed by different central stations, or "se". The pager's handoff while moving between "le" is when a plethora of frequencies are involved. Will be technically awkward.</p>

<p> A bidirectional paging system is for transmission between the pager unit and the central control station. , Uses 4 local frequencies. The first local frequency carries the local clock , The second local frequency carries the communication packet from the central control station to the paging unit. , The third local frequency carries the communication packet from the pager unit to the central control station, The fourth local frequency is the status or request from the paging unit to the central control station. Transport the strike signal. Transmission based on four local frequencies access the central control station Follows time-division slot allocation between existing pager units.</p><p> In a two-way paging system where multiple central control stations manage multiple corresponding cells Therefore, a total of eight frequencies are used in any one cell. Of the frequency used Four of them are local frequencies (which may vary from cell to cell) and are of the frequencies used. The remaining four are switching pager units that are moving from one cell to another. At the lower power common frequency or switching frequency used for handoff is there.</p>

The above objectives, features and effects of the present invention, as well as other objectives, features and effects, are attached. Clearly from the more detailed description described below of the preferred embodiments illustrated in the drawings of Will be. In drawings, the same reference number refers to the same part throughout the drawing. Na Oh, the drawings do not necessarily correspond to the actual scale, and are used to explain the principles of the present invention. There is a place that is emphasized.<figref num="1">Schematic diagram of a central control station included in a paging system according to an embodiment of the present invention.</figref><figref num="2">Schematic diagram of the pager unit included in the paging system used with the central control station in Figure 1.</figref><figref num="3">Flowchart showing each step performed by the central control station in Figure 1.</figref><figref num="4">Flowchart showing each step performed by the pager unit in Figure 2 in transmit mode</figref><figref num="5">Flowchart showing each step performed by the pager unit in Figure 2 in receive mode</figref><figref num="6">Timing diagram that reflects the communication between the central control station in Fig. 1 and the pager unit in Fig. 2.</figref><figref num="7">Schematic diagram of the central control station included in the paging system according to the second embodiment of the present invention.</figref><figref num="8">Schematic diagram of the pager unit included in the paging system used with the central control station in Figure 7.</figref><figref num="9">A hybrid schematic diagram and a timing diagram expressing the switching operation of the paging system according to the second embodiment of the present invention.</figref><figref num="10">A flowchart showing each step performed by the pager unit in FIG. 8 as a result of the channel switching operation.</figref><figref num="11">A flowchart showing each step performed by the central control station of FIG. 7 in association with the channel switching operation.</figref><figref num="12">Schematic diagram of the communication packet format used in each embodiment of the present invention</figref><figref num="13">Schematic diagram illustrating a time-division slot allocation technique according to the present invention.</figref>

FIG. 1 shows the central control station 20 according to the first embodiment of the present invention, and FIG. 2 shows the central control station 2 A pager unit 22 suitable for use with 0 is shown.

As shown in FIG. 1, the central control station 20 has a central computer 30 and a transmitter 32. And a receiver 34 and a computerized telephone answering system 36 .. The transmitter 32 has two local frequencies, i.e., frequencies, via the transmitting antenna 42. f₁And frequency f₂And send. The receiver 34 has two local frequencies, i.e., frequencies. f₃And frequency f₄Is connected to the receiver antenna 44 to receive. Computer The telephone answering system 36 is connected to a bank of telephones 48.

The central computer 30 of the central control station 20 has a CPU 50 and an I / O interface 52. And a conventional computer with typical components including memory 54. Figure Memory 54 is (for example) hard disk dry, although only outlined in 1 It has several memory elements (not shown), including memory, RAM, and ROM. Please understand. Figure 1 shows the page registration file with memory 54 (among others). It indicates that it stores the file 55 and the pager directory file 56. page File 55 and 56 are typically hard disk disks for central computer 30. It is stored on Eve and can be loaded into the RAM part of memory 54 when it is started up. Will be.

The central computer 30 of the central control station 20 (to encode the output communication information, I / With encoder 58 (connected between O interface 52 and transmitter 32), (1) Receivers 34 and I to decrypt input communication information from one or more pager units 22 It also has a decoder 57 (which is connected to / O interface 52).

The central control station 20 also has a local clock signal f₁clk (this time frequency f₁It is equipped with a clock unit 59 that produces (used to modulate).

As further illustrated, the CPU 50 of the central control station 20 has a frequency f.₂To transmit with Create a communication packet for. Communication packets, as schematically illustrated in FIG. Is in a predetermined format, and has a field for identifying the central control station and a. Field for identifying dressed (at least one) pager unit 22 And a field for arithmetic code, and (optionally) a field for alphanumeric information, Other traditional packets such as checksums, error correction and post ambles It has a field for type information and. Pre-ambling and post-ambling , Can be recognized and distinguished from data for the purpose of determining the beginning and end of a packet This is a particularly selected pattern. Alphanumeric information is in the conventional binary 8-bit format obtain. The format in Figure 12 is just an example. Because of the field This is because information such as order can be changed in other embodiments.

The central control station 20 has a plurality of pager units 22.₁、22₂、・・・22_NCommunicate with. Only one such pager unit (collectively referred to as paging unit 22) However, although it is specifically illustrated and described in the present specification, other pagers are used. It is reasonable that the configuration and operation of the device may be the same as this one pager unit described. I want to be understood.

As shown in FIG. 2, the pager unit 22 is connected to the pager receiver 62. It is equipped with a pager receiver antenna 60. What about the pager receiver 62? , Connected through the S / D converter 64 in the pager computer 70. Receiver 62 Is the two local frequencies f₁And f₂To receive. These frequencies are the input communication information ( Modulated to transport the pager computer 70 (more on this later) .. On the communication output side, the pager computer 70 outputs via the D / S converter 74. The communication information is output to the pager transmitter 72. The transmitter 72 is via the pager antenna 76. And two local frequencies f₃And f₄Broadcast the output communication information with.

As shown in Figure 2, the pager computer 70 is an arithmetic processor 82, (R. Memory system 84 (with both OM and RAM), and I / O interface It has a pager microprocessor 80 connected to each of the 86s. I The / O interface 86 is connected to the clock unit 87. I / O interface The booth 86 also receives the decrypted communication information input from the 8-bit decoder 88. And it is possible to output unencoded output communication information to the 8-bit encoder 90. It is connected so that it can be done. The decoder 88 is a coding input from the S / D converter 64. It is connected so that it can receive the communication information. Encoder 90 is a code It is connected so that the converted output communication information can be output to the D / S converter 74. ..

The clock unit 87 has a local clock signal f having a frequency corresponding to its input.₁It can be set by appropriate input to generate clk. In other embodiments In other words, the function of clock unit 87 is at least using programmed execution. It should be understood that even partly it can be executed by the microprocessor 80.

I / O interface 86 facilitates input and output with multiple input / output devices Therefore, it is also possible to supply an on / off signal to the pager transmitter 72 on line 92. It is connected so that it can be done. Input / output device connected to I / O interface 86 Keyboard 93, Beeper 94, Vibrator 95, LCD (alphanumeric) display Includes Ray 96.

At the time of manufacture, the pager unit 22 is stored in the memory 84 (ROM). Use a different serial number (for example, a 7-digit alphanumeric pre-assigned ID number) Is pre-programmed. Pager unit 22 (for example, at the time of purchase) A given address in memory 84 of knit 22 and rated in memory 54 of central control station 20 Timeslot allocation in both pager directory files 56 (supplied) Activated by inserting (discussed below). Operation of the first embodiment Communication between the central control station 20 and the pager unit 22 has four local frequencies, especially Frequency f above₁, F₂, F₃And f₄Happens in. First frequency (f₁) Is the center The local clock matching signal is carried from the control station 20 to the paging unit 22. No. 2 Frequency (f₂) Is a pager command from the central control station 20 to the paging unit 22. Transports alphanumeric data. Third frequency (f₃) Is centered from paging unit 22 Transport pager status data and alphanumeric data to control station 20. Fourth frequency (f₄) Transports the pager request signal from the paging unit 22 to the central control station 20. To. In this embodiment, the frequency f₁~ f₄Is preferably f₁ f₂ f₃ f₄Selected to be Be selected.

In the normal non-cell switching operation, as described in more detail below and as described in FIG. The frequency f₄The pager request signal in is specified for the paging unit 22 It is transmitted within the specified time slot. Frequency f₄The predetermined time slot in Lock matching signal (frequency f₁Related to (carried by) and the fourth frequency Is specified to be available by several other paging units. For example, Figure 1 Frequency f as shown in 3₄The first time slot in is designated as pager P1 , The second time slot is designated as pager P2, as well as the nth time slot Designated as pager Pn. In this embodiment, the number of time slots (and thus the pager) The number) can be as large as 10,000 or more.

Figure 3 shows the CPU of central control station 20 when processing communication with one or more paging units. Shows the steps performed by 50. The process shown in FIG. 3 is the memory 54 of the central control station 20. Indicates the instruction stored in the ROM section.

When the central control station 20 starts up (step 100), the initialization process (step 100) 102) is executed. Included in the initialization process is the activation of transmitter 32 (transmitter 32 is two frequencies f₁And f₂(To be able to transmit at) and activation of receiver 34 (receive) Credit machine 34 has two frequencies f₃And f₄To be able to receive). In addition, the frequency f₁Carry the local clock matching signal generated by the local clock 59 Modulated as Then, in step 104, the page registration family File 55 and pager directory file 56 are RA from hard disk to memory 54 It is loaded into the M section (step 104).

After initialization and loading of files 55 and 56, CPU50 gives instructions Repeat loop 106. Loop 106 has a phone message (in bank 48) Determine if one of the phones is receiving (via the answering system 36) Check for step 108) and the pager message (for paging unit 22) To determine if it is being received from one (via transmitter 32) (step 110) Includes checks and.

As used herein, the message is from the telephone or from the pager. Multiple for transmission from central station 20 to pager 22 and vice versa, whether or not It may require a number of packets. In the discussion below, one or more messages are sent and received. Including sending and receiving packets above. In general, message packetization is invisible to the user .. That is, the user considers the number of packets that can be needed to send a message. Enter a message without having to. The message is typically a user-entered message End with the end character or message delimiter. Transmitter (Central Station 20 or Pe 1 or more of which have a format similar to the format shown in FIG. Assign a message to the packet of. The last packet of the message is the message end statement Including letters. Also, the packet indicates the number of continuously related packets sent by the transmitter. It may be formatted in such a way (eg, serial number of related packets). There may be another packet field pointing to the bar).

I / O interface 52 varies to CPU 50 depending on the type of message received Due to the fact that it generates a type of interrupt, the central computer 30 has a telephone message. Distinguish between receiving a page (step 108) and receiving a pager message (step 110) can do. In step 108, it is determined that a telephone message has been received. If so, steps 112, 114, and 116 of FIG. 3 are performed.

In processing the received telephone message, in step 112, central computing The data 30 extracts communication information for transmission from the input data whose order has been determined in advance. Bank 4 Data entered from the phone via the touchpad of one of the phones in 8 is customarily electronic. Talk identifier (eg phone number) and identifier of the called pager unit (eg 7 sentences) A pre-specified ID number in alphanumeric characters and one of the character data for transmission and the end Including letters. This transmission communication information is in standard DTMF format on the central computer 3 Received by 0.

In step 114, the central computer 30 is the ID number of the called pager. Pager registration file 55 and dire using (obtained in Tep 112) Central control of the called pager unit by checking with the client file 56 Determine if it is registered with station 20. If the called pager is registered, medium Central computer 30 is the slot designated for the called pager unit in step 114. Is also obtained from the pager directory file 56.

In step 116, the central control station 30 sends communication information to the called pager unit. Believe. In this regard, the central control station 20 has the ID number of the called pager unit, And a communication message containing character data received from the transmission telephone of the pager unit 22 Create a page and (frequency f₂By) to send. Process after step 116 is performed Returns to loop 106.

If it is determined in step 110 that a pager message has been received, then ( Even steps 132-140 in Figure 3 are performed (before returning to loop 106). See Figure 4 And where the sending pager unit 22 sends the message, as described below. When desired, the sending pager unit 22 has a frequency during the specified time slot. f₄Sends a request signal. Central control station 20 always has frequency f₄Is monitoring Therefore, the frequency f₄Which pager unit 22 is the request signal carried by It will be noted even if they are. CPU50 steps with respect to local clock 59 At 132, frequency f₄Find out in which time slot the request signal is detected Determine. If a time slot is detected in step 132, CPU 50 steps At 134, generate a request signal by referencing pager directory file 56 Determine the ID number of the specific pager unit 22 that was created.

When the ID of the requesting pager unit 22 is known, the central control station 20 takes step 1. At 36, allow the requesting pager unit 22 to send the message .. In particular, CPU50 has a frequency of f₂Instructs the creation of a communication message for transmission by. Step The specific communication packet created in P136 is the identifier of the requesting pager unit ( The destination of the packet) and the requesting pager unit 22 to send the message. Includes operation code ("operation" code) that commands / permits and.

In step 138, the central control station 20 is the sender (eg, requester) page. Frequency f from unit 22₃Receive the communication message sent by. Sender page The communication message created and transmitted by Jaunit 22 is the four shown in FIG. A packet that contains a packet in a format similar to Matt and the message is finally sent. Includes the identifier of the adjuster and the identifier of the packet itself. In step 138, CPU50 The final destination pager unit is registered in pager files 55 and 56. Check to confirm that it is. In step 140, CPU5 0 does any necessary reformatting and / or replacement in the message , The message is frequency f₂To be sent by. Frequency required in step 140 Number f₂The transmission by is different from the identifier of the final destination (for example, pager unit 22). Operation code indicating that the message relayed from the pager unit is included. Including.

FIG. 4 shows the steps performed by the pager unit 22 in relation to the transmission mode. pager The steps performed by the unit 22 in relation to the receive mode are shown in FIG. In the present specification The term "mode" does not exclusively refer to a particular moment. Because the pager Unit 22 always has frequency f₁And f₂This is because it is receiving the transmission by.

In transmit mode (see Figure 4), after startup (step 200), the sender The microprocessor 80 of the gear unit 22 executes loop 202. Loop 202 In, the user's alphanumeric characters (entered via keyboard 93) are the end of the message It is fetched repeatedly (step 206) until the delimiter indicating the end is detected (step 206). Tep 204). The characters entered and fetched in step 204 are displayed on the LCD display. Displayed on 96. By entering the delimiter in step 206, the microp The Rossessa 80 exits Loop 202. By convention, the message contains the destination ID and is addressed to the above. The destination ID is another pager unit to which the message entered in step 204 is directed. Tends to be an ID.

After the message entry, in step 212, the transmission frame from the keyboard 93 Wait for the entry. If the send command was entered in step 212, MicroPro Sessa 80 generates a request signal and frequency f₄To send by. As mentioned above The quest signal circulates within the time slot specified for the requesting pager unit 22. Wave number f₄Is sent by. Pager unit 22 always has frequency f₁Local cross by It is receiving a matching signal, which causes the microprocessor 80 to receive a specific sender page. Frequency f at the time corresponding to the specific time slot assigned to Jaunit 22₄Note that this makes it possible to send a request signal.

Regarding the above, each pager unit 22 according to the time division technology₁~22_N(For example, Figure 1 3 pager P₁~ P_n) Has frequency f₄1 selected from N time slots Is specified.

After transmitting the request signal in step 214, the pager unit 22 is centrally controlled. Wait for the transmission command from station 20 to be received. Transmission command / transmission permission from central control station 20 The creation and transmission of the above will be described with reference to FIG. Send command / send from central control station 20 After receiving the authorization (step 216), the microprocessor 80 is in the format shown in Figure 12. Create a communication message containing one or more packets with a very similar format (Step 218). The destination ID of the communication message and the alphanumeric field of the packet are Full with messages entered during loop 202. In step 220, the sender Pager unit 22 has frequency f₃Broadcasts communication packets.

If no send command is entered in step 212, or in step 220 After sending the message, in step 222, the microprocessor 80 has some possible Wait for an entry for at least one of the special features available. For example, the user has a message Fans that need memory [step 228] (whether or not it has already been sent) You may press the action key. The user can also edit the message (see step 224). ) Or press a function key to facilitate erasing (see step 226) .. To end a message and start working on the next message, exit Operation (step 230) You must press the dedicated function key.

Figure 5 shows the microprocessor 80 with respect to the pager unit 22 in receive mode. The process to be executed is shown. After startup (step 302), as shown in step 304 In addition, the pager unit 22 has a frequency f from the central control station 20.₂Receive transmissions by. Complete When all packets are received (determined in step 306), the destination ID in the communication packet (figure) Whether or not (see 12 packet formats) is the ID of the receiving pager unit 22 Checked (step 308). The judgment of either step 306 or 308 is NO If so, the pager unit 22 terminates the communication packet by returning to step 304. Finished (if the determination in step 306 is NO) or reception of another communication packet (step 30) (If the judgment of 8 is NO) Wait for one of them.

Received communication packets are assigned to this particular receiving pager unit 22 If, in step 310, the microprocessor 80 operates the communication packet. The message contains a command by referencing the code field (see Figure 12). It is determined whether or not the operation code indicates that the operation code is to be used. The operation code is When indicating a command, the command processing routine (enclosed by the dashed line 312 in Figure 5) is actually To do.

If the operation code does not indicate a command, in step 314, page 314. The microprocessor 80 of the jaunit 22 is the alphanumeric field part of the communication packet. (Forming at least one part of the sage) is stored in the RAM part in the memory 84. Central processing The message communicated from station 20 has several communication parameters to terminate the message. A packet could be needed (along with the next communication packet that provides continuity of message content) Therefore, the microprocessor 80 received the entire message in step 316. Check to confirm. If the entire message has not been received, the process Return to step 304 to receive further communication packets.

When the entire communication message is received, the microprocessor 80 goes to step 318. Then, it is determined whether the pager unit 22 is in the beep mode or the vibration mode. This In this regard, the dedicated switch on the pager unit 22 or the keyboard 93 is used. There are many ways to set the pager unit 22 to the desired mode by data entry. To. If the pager unit 22 is in beep mode, the microprocessor 80 is a beeper. Output a signal that generates an additional signal to the I / O interface 86 that activates 94 (Step 320). Also, if the pager unit 22 is in vibration mode, MicroPro The Sessa 80 provides additional signals to activate the vibrator 95 on the I / O interface 86. Outputs the signal generated in (step 322).

In step 324, the microprocessor 80 receives a message from the user. Send alphanumeric message data to LCD display 96 for viewing Instruct the I / O interface 86 to do so.

Received alphanumeric data to the user (Beeper 94 and / or Vibrator 95) After notifying (via) and displaying (on LCD96), the microprocessor 80 is Go back to step 304 and check if more communication packets are being received.

The command processing routine (enclosed by the dashed line 312 in Figure 5) begins with which particular operation. Determine if the command is being commanded (step 330). This judgment is an operation It is based on the content of the code, and the content of the above operation code is a different type of code. Not for mands. If the operation code indicates an error shutdown , Execution of processing proceeds to the error shutdown subroutine starting from step 340. Oh If the perlation code indicates a time slot change, execution of the process is step 350. Proceed to the time slot change subroutine starting with. The operation code is the transmitter If you need a down, the execution of the process starts at step 360 Transmitter shuffle Proceed to the to-down subroutine. Operation code requires transmitter re-enablement In short, the execution of the process goes to the transmitter re-enablement routine starting at 370. move on. If the operation code requires a clock reset, the execution of the process will be Proceed to the clock reset subroutine starting from 380.

Regarding the error shutdown subroutine, in step 342, the micropro The Sessa 80 obtains the error type indication from the communication packet. The error type is memo Stored in Li 84 (step 344) and then displayed on LCD Display 96 (Step 346). Microprocessor 80 shuts down pager unit 22 Issue a command to shut down (step 348) and shut down at step 349 ..

Regarding the time slot change subroutine, in step 352, microprocessor 8 0 is the new tie specified for the receiving pager unit 22 from the received communication packet. Extract the information that indicates the Muslot. The new time slot is entered in memory 84 (Step 354), then frequency f₄In connection with the transmission of the request signal by (further It will be used (until changes are made) (see, for example, step 214 in Figure 4). Thailand The muslot change subroutine eliminates (for example) unused time slots if desired. Eliminating (and thereby increasing scanning speed), diagnostics and troubleshooting, Includes other operations, including interrupts to service from a failed or malfunctioning device It doesn't matter.

With respect to the transmitter shutdown subroutine, in step 362, micropro Sessa 80 instructs I / O interface 86 to issue off-command to transmitter 72 To do. Regarding the transmitter re-enablement subroutine, in step 372, My The cross processor 80 sends an on-command to the transmitter 72 so that the I / O interface 8 Instruct 6.

With respect to the clock reset subroutine, in step 382, the microprocessor The server 80 instructs the clock 59 to set the pager unit 22.

After executing step 354, 362, 372 or 382, executing the process is step 30 Go back to 4 and process further communication packets that may need to be processed. In this way, d Command processing routines (enclosed in dashed line 312 in Figure 5) until the shutdown is notified. The loop up to step 304 is executed after the entry.

Figure 6 shows, in particular, the sender for sending a message to the destination pager unit P2. Frequency f for request by pager unit P1₁~ f₄And shown in Fig. 3 to Fig. 5. It is a timing diagram which shows the integration of steps. In Figure 6, the term "computer" is used. Indicates the central control station 20. Sending pager unit P1 and destination pager unit P2 Understand that it works in both the transmit mode shown in Figure 4 and the receive mode shown in Figure 5. I want to be. Figure 6 is generally a page from pager unit P1 (via central control station 20). Sending a message to unit P2 and from pager unit P2 (central control station 20) Sending a confirmation message to the pager unit P1 (via) and the pager unit P1 The page of the message indicating that the confirmation message from the pager unit P2 has been received. Indicates transmission from unit P1 to central control station 20. Structure of the second embodiment FIG. 7 shows the central control station 420 according to the second embodiment of the present invention. Figure 8 shows the central control station Shown is a pager unit 422 suitable for use with the 420.

FIG. 9 shows a wide area paging system including a plurality of central control stations S1 to S8 (each central control station). 20), and each central control station S1 to S8 is preferably geographical within each cell. Located in the center. Each central control station S1 ~ S8 has its own local frequency and one set Common or switching frequency C₁~ C₄And broadcast. Common frequency C₁~ C₄Is , Its reception is in a relatively narrow range around the central control station or common frequency reception area (CFRR) [ Broadcass with relatively low power, as it only happens in the "switching area"] To be done. Local frequencies are much larger so that they can be received virtually entirely in the cell. Broadcast by force. For example, in FIG. 9, the central control station S1 has a relatively low power consumption. Common frequency C₁~ C₄CFRR₁Broadcast to a relatively high power local frequency f₁~ f₄CELL₁Broadcast to. Central control station S2 has a relatively low power common circumference Wave number C₁~ C₄CFRR₂Broadcast to a relatively high power local frequency f₅~ f₈CELL₂Broadcast to.

This is also CELL, as shown in Figure 9.₁And CELL₂Overlaps in the overlapping area shown in FIG. Station S1 is a set of local frequencies f₁~ f₄Using station S2, another set of loca Frequency f₅~ f₈To use. Stations S1 and S2 have the same set of common or switching laps Wave number C₁~ C₄To use. In this way, each central control station uses two sets of frequencies and each Since there are 4 frequencies in the set, a total of 8 frequencies are handled for each station.

As described above, the second embodiment of the present invention is a plurality of central control stations 420._{x, y = 1,2, ... M}Have Suitable for systems. Each central control station 420_xTo the relevant geographic range or cell And one set of local frequencies f_L1, F_L2, F_L3, And f_L4Common or switch with Frequency C₁, C₂, C₃, And C₄And send and receive. Local frequency f_L1, F_L2, F_L3, O And f_L4The value of varies from cell to cell (eg, different central control stations 420)._xDifferent for ) Is common or switching frequency C₁, C₂, C₃, And C₄The value of is throughout the system (For example, all central control stations 420_xIs uniform.

Although not shown in Figure 9, the central control station pattern is a given geography of the paging system. It should be understood that it repeats in all directions as well, depending on the target boundary. In addition, Figure 9 shows Although not specifically indicated, it was understood that each central control station 420 has an associated CFRR. I.

Common or switching frequency C₁~ C₄Each corresponds to the local frequency f₁~ f₄Against It has a similar function. In this regard, frequency C₁To the central control station (s) Carries the transmitted clock frequency, but has a common frequency C₁Clock rate is suitable Is different between central control stations. Frequency C₂From the central control station (s) Used to send information to the knit (s), frequency C₃Is pager uni Used to transmit information from the computer to the central control station, frequency C₄Sends a request signal Used by the pager unit to grow. Frequency C₂Is the former shown in Figure 12. It carries packets with a format similar to that of the packet. Frequency C₂Transported by Ket has a frequency of f₂It may have a command code in a format similar to. C₂command The code includes SYSTEM COMMAND CODE, LOCAL FREQUENC Y DOWNLOAD COMMAND CODE, SLOT RECOGNITION COMMAND CODE and SLOT ASSIGNMENT COMMAND CODE is included.

As shown in FIG. 7, the central control station 420 is similar to the central control station 20 of the embodiment of FIG. (Similar components have the same reference code for brevity). But central control station 42 0 is the common frequency C₁And C₂Known as the Common Frequency Transmitter 432 for transmitting Additional transmitters are augmented by including a common frequency transmit antenna 442. Big In contrast to the power transmitter 32, the transmitter 432 is a low power transmitter. In addition, the central control station 420 is the common frequency C₃And C₄Known as the common frequency receiver 434 for transmitting Additional receivers to be augmented by including with the common frequency receiving antenna 444 ..

The central control station 420 in FIG. 7 has two clock signals, in other words, the first or local. Clock signal f_Lclk and the second ie common clock signal C₁Crock to generate clk Includes unit 59'. Local clock signal f_Lclk is the frequency f₁Modulate The common clock signal is frequency C₁Is used to modulate.

Central control station 420_xCentral computer 30 has output line 486A and input line 486B More connected in series with each other. In particular, although not explicitly shown in Figure 7, the compute in Figure 7 The data 30 (similar to that in Figure 1) is the I / O to which the series connection lines 486A and 486B are connected. Includes interface. Series connection lines 486A and 486B are, for example, pager registrations. Update the contents of the tration file 55 and the pager directory file 56 Used for

As shown in FIG. 8, the pager unit 422 is the pager unit 2 of the embodiment of FIG. Similar to 2 (again, similar components are given the same reference code for brevity) ). However, the pager unit 422 (in a similar fashion to the central control station 420) has a common frequency. Number C₃And C₄A further transmitter known as the Common Frequency Transmitter 572 for transmitting Is supplemented by including with the common frequency transmitting antenna 576. In addition, central control Station 420 has a common frequency C₁And C₂As a common frequency receiver 434 for receiving Augmented by including additional known receivers along with the common frequency receiving antenna 444 To.

The operating frequencies of the transmitter 72 and receiver 62 are from the computer 70 on the "frequency control" line. It is variable depending on the value transmitted via. In particular, the frequency control line is inside the computer 70. It is connected to the I / O interface 86 of. Page as described in more detail below When the unit 422 is moved to the new CFRR, the pager unit 422 is moved to the old cell. Related to the new CFRR to which the pager unit 422 is moved from its local frequency A signal is added to the frequency control line to switch to the local frequency of the new cell.

The pager 422 is a local clock signal f used by the microprocessor 80._Lclk And common clock signal f_c1Clock unit 83'that can generate clk and separately including. Each of these clock signals is properly input to the clock unit 83'. Therefore, these clock signals are initialized and the frequencies of these clock signals are set. To.

Figure 8 also shows that the pager unit 422 has an alphanumeric and graphic display and a pressure sensitive writer. Shown that it has a data I / O unit 596 with both a wing pad. Alphanumeric And the graphic display is a dot matrix device that can display characters and graphics. It is a chair. The writing pad has a 16x48 dot area. Operation of the second embodiment As shown in FIG. 9, the pager unit P1 is CELL.₁Works within and is already station S1 Common frequency C₁~ C₄And local frequency f₁~ f₂Is considered to have been received. page The unit P1 moves on the route indicated by the dashed line ROUTE with an arrow. Pager unit When P1 moves along a ROUTE, even when moving areas where cells overlap Local frequency f₁~ f₂Continues to work with. However, the pager unit P1 is new Frequency reception area (ie CFRR₂), Switching or handoff operation Occur. In the switching operation, the pager unit P1 as described in more detail below. Is the common frequency C from the central control station S2₁~ C₄And as a result, CELL₁Local Frequency f₁~ f₄, CELL₂Local frequency f₅~ f₈Can be switched to. Off Pager unit P1 switches channels to perform a switch or handoff operation. The central control station S2 executes the switching enable routine.

Regarding the channel switching routine and the switching enable routine, the pager unit P1 is CFRR₂When moved to, the pager unit P1 goes around the clock signal from station S2. Wave number C₁Received by. At this time, the pager unit P1 automatically performs its clock uni. Matches the clock signal from station S2.

Channel off performed by pager P1 following startup (step 500) According to the replacement routine, in step 506, the pager unit P1 is in station S2. Get the information that characterizes your system of mind. System knowledge of such characterization information Called Besshi or system ID information.

In step 508, the microprocessor 80 of the pager unit P1 has a frequency. C₂Check to determine if there is new system ID information obtained by U. That is, in the microprocessor 80, the system ID information is frequency C.₂Received by Check to determine if it is possible (it can only happen within CFRR) and if frequency Number C₂If received by, the system ID information and the system ID information stored immediately before Compare. The previously obtained system ID and the most recently obtained system ID are the same If so, the pager unit P1 is the station where the pager unit P1 is still the same (eg station S). Recognize that it is within the jurisdiction of 1). Previously obtained system ID and most recently obtained If the system ID is not the same, the pager unit P1 will be the pager unit P1. Recognize that you have entered the CFRR of a new station (eg station S2) and go to step 510 CELL a request to communicate with a central control station (eg station S2)₂Against Frequency C₄Start with.

Regarding the above, the pager unit P1 is still CELL₂Time slot is specified Frequency C₄Requests are made randomly. But pager Unit P1 is the time to make a request to a new central control station (eg station S2) Keep recording slots.

After that, the pager unit P1 has a frequency C from station S2.₂Monitor communication packets by Continue (step 512), station S2, pager unit P1 request in step 510 Wait for a message to refer to the time slot that went on strike. Especially the pager Unit P1 has frequency C from station S2₂Message by SLOT REC OGNITION COMMAND CODE and pager unit P1 are randomly generated Wait for a message that contains both the information created and the information stored in the same time slot Tsu. Messages containing SLOT RECOGNITION COMMAND CODE Includes station S2 as the sender and is randomly generated by pager unit P1 Reflect the slot created. Therefore, the pager unit P1 pagers the message. Recognizing that it was directed to unit P1, issuing such a message by station S2 (Figure) 11), but the pager unit P1 communicates further with station S2. Think of it as allowing. In this regard, in step 514, Pageyayu Knit P1 microprocessor 80 has the time slot and station of the received message. Judge whether or not it matches the time slot for which a random request was made in P510 To do.

If it is determined in step 514 that the final match is made, in step 516, the page Jaunit P1 sends communication packets to frequency C₃To send to station S2. The above communication package Contains the identifier or ID of the pager unit P1. Station S2 is a pager resist The ID of the pager unit P1 is a valid ID using the relation file 55. And then the command code LOCAL FREQUENCY DOWNLOAD Message to pager unit P1 with (Frequency C)₂By) to send. The above message The sage is on the pager unit P1 at the local frequency handled by the station S2 (eg, the circumference). Wave number f₅~ f₈) Is given. Then station S, as also shown in step 518. 2 has the command code SLOT ASSIGNMENT COMMAND CODE The received message is sent to the pager unit P1 (frequency C).₂By) to send. Above message The frequency f is attached to the pager unit P1.₈Notify the slot designation for. Then ma The icroprocessor 80 has the steps described above for the time slot change routine (Figure 5). Slot allocation by steps similar to steps 350, 352, and 354) Change the guess. Step 518 of FIG. 10 is for receiving the local frequency value and specifying the slot. Indicates reception.

After all local frequencies have been acquired and slotted (step 520), the micro Processor 80 has a new local frequency (eg frequency f)₅~ f₈) To switch to (Step 522). In this regard, the microprocessor 80 has a transmitter 72, Frequency f₃And f₄From frequency f₇And f₈I / O interface 8 to change to Instruct 6 and receiver 62, frequency f₁And f₂From frequency f₅And f₆Change to Instruct I / O interface 86 to do so. I / O interface 86 is an I / O Appropriate values for the frequency control lines that connect the interface to the transmitter 72 and receiver 62, respectively. By granting, the frequency change is achieved.

After switching to the new local frequency in step 522, the microprocessor 80 returns to step 506 and finally determines if further switching is needed. ..

Involved in the switching enable routine performed by the central control station (eg station S2) The steps are shown in Fig. 11. After startup (step 600), CPU50 is C PU50 organizes pager directory file 56 and one of the new pages Checking if the Jaunit is in a cell within the jurisdiction of CPU50 Execute loop 602 to enable.

In particular, in step 604, the CPU will eventually have its central control station (eg, S2). By any other central control station (eg S3) so far that central control station (eg S2) The pager unit that was under the control of is now under the control of another central control station (eg S3) Determine if you have been notified. Such notifications are central control station 420_xConnect Occurs on serial links that do, especially on the input serial link 486B. If such a notification occurs, another Is the ID of the pager under the control of the central control station of station S2 pager directory 56? Are deleted (shown in steps 606 and 608).

In step 610, CPU50 sets the SYSTEM COMMAND CODE. The prepared message is frequency C₂To be sent by. As mentioned above, frequency C₂To The message sent by is a packet (singular) having the format shown in FIG. Or more than one). Messages with SYSTEM COMMAND CODE are special Includes the central office ID number in the alphanumeric data field.

In step 612, the central control station 420 is assigned to one of the pager units 422. More frequency C₄Request was sent by (eg, Figure 10, especially step 510). Check to determine if it is (as explained with reference). Such a request The signal is CFRR controlled by the central control station (eg CF controlled by station S2). RR₂) Tends to be issued by the pager unit 422 that has just entered. this If no such request signal is detected, loop 602 is repeated again.

If a request signal is detected in step 612, the central control station 420 will specifically Frequency C₄Note the time slot in which the request occurred. (Step 614). At this time, the central control station 420 entered only by such a time slot. -Ja unit 422 can be identified. Central control station 420 is an intricate page Unit 422 wants to send its identifier (ID), but the detected time slot It is possible to identify the destination of the intruded pager unit only by referring to the I can't. In step 616, the central control station 420 is SLOT RECOGNITI. Create a message with ON COMMAND CODE and frequency C₂Sent by To do. Messe with SLOT RECOGNITION COMMAND CODE The page includes the station S2 as the transmitting side and is randomly generated by the pager unit P1. Slot (for example, the intruded pager unit 422 issued the request Im slot) is reflected. Frequency C₂This transmission by pager unit P1 Allowing the transmission of identifiers.

Step 618 is central control of the identifier (ID) of the intruded pager unit 422. Shows acquisition by station 420. In step 620, the central control station 420 is a pager I. Pager registration file 55 to determine if D is a valid ID Check. If it is not a valid ID, an error message will be generated and sent (s) Tep 622), followed by a command to shut down pager unit P1 (See step 624).

When the identifier of the pager unit 422 is determined to be valid in step 620 If so, CPU50 checks pager directory file 56 (step 630). By doing so, search for a time slot that can be used for the intruded pager unit 422. Search for the next available time slot and the ID of the pager unit 422 that entered. Associate. Then, in step 632, the central control station 420 is LOCAL FR. Frequency C with EQUENCY DOWNLOAD COMMAND CODE₂By The value of its local frequency (eg f₅, F₆, F₇, And f₈) Is sent to the intruded pager unit 422. The central control station then SLOT AS Frequency C with SIGNMENT COMMAND CODE₂For messages by And the pager unit 42 that entered the new time slot of that local frequency Specify in 2 (step 634). Time slot by the intruded pager unit 422 The processing of the change command is similar to the example shown in Figure 5, especially steps 350, 352 and 3. It is understood by referring to 54.

At the end of step 634, the entered pager unit 422 will have a new cell ( For example, CELL₂) Is under full control and the previous control station (eg CELL)₁And station It is out of the jurisdiction of S1). Therefore, in step 636, the CPU 50 gets in. Notify (using the pager ID) that the pager 422 is under the jurisdiction of the new cell Ask the I / O interface to issue the command over the serial connection line 486A. Est. This causes the previous competent authority (eg S1) to have its pager directory. You can remove this pager unit from file 56. Such deletions are as described above It is understood by referring to steps 604 to 608.

Figure 9 shows the pager unit P1, stations S1 and S2, and CELL.₁And CELL₂When In addition to explaining the geographical location of the common frequency C₁~ C₄Relative tie of communication occurring on Indicates mining. Figure 9 in particular shows Central Control Station 420 (Switchable Enable Routine in Figure 11). And pager unit 422 (channel switching routine in Figure 10) Regarding the timing of a plurality of specific steps among the described steps.

Central control station 420_xIs the same common frequency C₁~ C₄Is used, but the central control station 420_xThere is no interference or confusion between these signals transmitted from. Common frequency C₁~ C₄Are both Frequency C₁~ C₄Reception is central control station 420_xOccurs only in a limited area around (CFRR) As you can see, the local frequency f₁~ f₄It is broadcast with less power than. Subordinate Therefore, the pager unit 422 that moves in the system has a limited and unique CFR. Common frequency C only within R₁~ C₄To receive.

Cell diameter, CFRR diameter, local frequency (eg f₁~ f₄) Power level, and Common frequency C₁~ C₄System operating characteristics such as power level are especially covered by the system It can be adjusted field by field to suit many factors, including the terrain and terrain of the area. .. In one embodiment that does not limit the invention, the radius of each cell is about 20 miles and each C The radius of the FRR is less than about 10 miles. Transmission of local frequencies in the same embodiment Power can be in the range of about 3 watts to 1000 watts, common frequency C₁~ C₄Transmission power The force is preferably 2 watts or less.

Thus, the present invention is independent of the telephone system for wireless data communication between users. Provides a two-way paging system that works with. The present invention is in any given cell On the other hand, only 4 local frequencies f₁~ f₄And (multiple cells cover a wider area (To) Only 4 common or switching frequencies C₁~ C₄By using Minimize the use of available frequencies permitted by the Federal Communications Commission (FCC). Use Time division sharing technology by minimizing the number of frequencies (eg channels) And synchronization techniques are used. The transmission power difference between the local frequency and the common frequency is also Used. These techniques separate data transmissions between different pagers, thus deducing them. Data merging is eliminated.

The switching technique of the present invention reduces the number of frequencies used in the cell to 4 (eg, 4 loca). By increasing from (le frequency) to 8 (4 local frequencies and 4 common frequencies) It expands the geographic range of operation and minimizes paging time.

Multiple single pager registration files related to pager ID verification Stored in only one memory file of the central control station, and in that case To recognize is to search for the pager ID in the above one (remote) memory file. Issuing a search command (via serial link 486), the result of the search is questionable Please understand that it will be reported to the central control station.

The keyboard herein is, in some embodiments, eg English, Chinese, or Or it can be a multilingual keyboard or writing pad that allows Japanese typing To. Writing pads are available in Japan, Thailand, and China, where alphabets like English are not used. Especially useful in countries in the Near East, or in China. The writing pad also scans shapes It can also be used to ketch and transmit. Further data compression in connection with data transmission / Stretching techniques can be used.

Although the present invention has been described and described with reference to specific preferred embodiments, those skilled in the art will appreciate it. For example, various modifications of form and details are possible without departing from the idea and scope of the present invention. Understand that. For example, if the pager unit is far away from the central control station Repeaters can be used within the cell to facilitate transmission.

Embodiments of the present invention for which exclusive ownership is claimed are defined as follows.