Transmitting long alphanumeric and pixel data over radio-pager POCSAG network - separating information, assigning data regarding separation to each part and transmitting, and combining parts at receiver using assigned data

SWISS CONFEDERATION

FEDERAL OFFICE OF INTELLECTUAL PROPERTY ί?

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Invention patent for Switzerland and Liechtenstein

Swiss-Liechtenstein Patent Protection Treaty of December 22, 1978 © PATENTSCHRIFT as © CH 683052 A5 © Int. Cl.⁵: H04B 7/26

H04L 12/00

G08B 5/22

H04Q 7/02

<td>@ Application number:</td><td>487/92</td><td>@ Owner: Erika Köchler, Samstagern</td>

<td>© Registration date:</td><td>19.02.1992</td><td>© inventor: Lax, Alexander Peter, Freienbach Iten, Anton, Mollis</td>

<td>© Patent granted:</td><td>31.12.1993</td><td></td>

<td>© Patent publication published:</td><td>31.12.1993</td><td>© representative: E. Blum &amp; Co., Zurich</td>

© Method for transmitting long messages, especially pictures, in a paging network.

In a paging network, long messages are transmitted in such a way that they are first divided into individual messages. Each individual message contains one

Addition that allows the pager to correctly assemble the long message from the single messages. The individual messages are transmitted completely independently in the paging network. In this way, long messages, especially images, without overloading the network and low probability of disturbed reception of the total message transmitted.

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CH 683 052 A5

description

The invention relates to a method for transmitting long messages to individual paging receivers in a paging network, in particular a network with a limited permissible message length. Furthermore, the invention relates to a radio paging receiver for carrying out the method and a paging terminal. Paging networks, also as paging networks or Paging networks can be constructed as local or statewide systems that transmit digital signals to small, portable pagers (pagers) to extend the telephone network via radio stations or so-called base stations. To the recipient digitally encoded alphanumeric messages, such as the name of a person to be called by the carrier and their telephone number, or any other messages can be transmitted. The serving as a pager devices are ausgestaitet that they receive the radio signals of the base stations with high transmission speed safely and recognize the message transmitted therein, and can display on a display device. In the case of a newer paging receiver, a display field with a large number (for example 32 × 100) pixels is provided for displaying the message, which allows the display of several lines of text. The display fields are usually designed as an LCD element.

The transmission of the alphanumeric messages is carried out in the standardized POCSAG format (CCIR recommendation 584, 1982), using an ISO 7-bit letter encoding for the Latin letters (ISO standard 646). Each letter of the message is assigned a 7-bit binary word on the transmitter side according to this coding table. On the receiver side, the received message is decoded and fed to a character set memory (ROM) in which this table is also stored. Each 7-bit word is assigned the associated letter using this memory. On the display field, the thus determined characters of the message are displayed as lined-up characters in 5x7 dot matrix representation.

If special characters are to be shown which are not provided in the table, then the table must be expanded. This requires the programming of a ROM block with a corresponding table. This is also necessary for non-Latin character sets (eg Arabic, Japanese, Russian characters), whereby very large tables or ROM storage capacities are necessary for such character sets. The programming of such ROM memory is time consuming and expensive.

It is therefore desirable, on the one hand, to be able to transmit messages as their graphic image, so that no font memory is required for, for example, Chinese characters. These are image-wise captured as an image, transmitted pixel by pixel and displayed on the dot matrix display of the receiver constructed from pixels. In this way, any images can be transferred.

In particular, in the described transmission of pixels, but also generally in the transmission of long alphanumeric messages, ie using the character set memory, the problem arises that long messages can overload a paging network. Furthermore, the probability of disturbing long messages increases, which may affect their correct reception or playback. It is therefore the case that there is usually a limitation of the maximum message length in the paging network.

It is an object of the invention to remedy this situation and to allow the transmission of long messages to the pager. On the one hand for long alphanumeric messages, on the other hand, but especially for the pixel-by-pixel transmission of messages.

The object is achieved in a method of the type mentioned above in that the long message is broken down into at least two parts and each part is provided with an addition containing information about the division of the overlong message, where part and addition are each not a predetermined message length exceed that the parts with their respective addition are transmitted on the paging network as independent individual messages, and that in the paging receivers addressed by the transmission, the independent one-time messages are assembled on the basis of the additional information for the overlong message.

The addition, which can be made in a format that is acceptable to all paging center encoders, allows the long message in the paging receiver to be composed of the individual messages that do not necessarily arrive in the correct order in the paging receiver. In this way, long messages that are longer than the conventionally allowed messages can be split into single messages of lesser, allowable length. In this way, the paging network is not blocked, but used efficiently. If parts of the long message are faulty, they can be replaced on re-transmission. Parts of a long message can also be changed to form a new long message; only the changed part has to be transmitted again. The probability of correctly receiving a plurality of short messages may be higher than that of correctly receiving a long message.

Preferred embodiments of the method are defined in claims 2 to 12.

A preferred field of application is in particular in the transmission of characters and images as a sequence of pixels, which amounts to large amounts of data, which is equivalent to long messages.

By coding the graphic image of the message and the pixel-by-pixel transmission and

CH 683 052 A5 the corresponding decoding and display on the display, eliminating the need for a coding / decoding table, or for the character set ROM. Any characters are transferable pixel by pixel. It can also be transmitted Biiddarstellungen that use the entire display panel.

Preferably, however, the transmission is optionally switchable with the previous character set table or the graphic transmission. On the one hand, this allows the fast transmission of already letter-encoded letters and allows switching to graphic transmission for the special characters not recorded in the table. Instead of this switching within a message can also be provided to switch only between different messages, so that a message is sent as a character-coded only, the next message as exclusively coded graphically.

In the claims 13 and 16, a portable radio pager or a paging terminal are defined for performing the method.

Preferably, in particular the paging receiver is provided with a character set memory and a switching arrangement, by means of which selectively switchable the presentation of the message with fixed programmed characters from the memory or with graphically transmitted characters.

In the following embodiments of the invention will be explained with reference to the drawings. It shows

Fig. 1 shows schematically the structure of a paging network;

Fig. 2 shows schematically the structure of a radio paging receiver according to the prior art;

Fig. 3 shows schematically the structure of a radio paging receiver according to a first Ausführungsbeispiei of the invention;

4 shows the representation of a graphically transmitted message;

5 schematically shows the structure of a radio paging receiver according to another embodiment; and

Fig. 6 shows the representation of a graphically transmitted letter.

A paging network is shown in FIG. 1 from a paging terminal 13 to 18 and a plurality of portable pager 19 together. In a paging terminal (Paging Terminal) 14, which is the link between the public telephone network 13 and the paging system, the subscriber data are managed and the incoming calls in suitable for the paging system, serial data streams, eg in the so-called POCSAG format implemented.

A paging network unit 15 is connected to the paging center and collects a certain number of calls each in a data packet. Each data packet is coded accordingly and provided for further transmission. The calls are buffered so for the transmission. The network control unit is also responsible for the synchronous transmission of paging. For this purpose, it provides each paging with a Zeitstempei, which determines the date of its transmission.

Several locally distributed transmitter group controllers 16 are connected to the network controller (via telephone lines). These transmitter group control units distribute the data packets they receive from the network control unit to the actual paging transmitters or base stations.

The base stations 17, each of which are connected to a transmitter group control unit (via telephone line), represent the end of the wired or the originating point for the radio transmission of the calls. The base stations broadcast the calls to the Receiver resent.

The pagers (paging receivers) 19 are carried by the participants and receive the addressed to them paging. According to the block circuit diagram of FIG. 2, which shows in a highly schematic manner a prior art paging receiver, a receiver circuit 1 is provided therein for receiving the paging signals at one or more specific frequencies. The received digital bit strings are delivered to a data processing circuit or decoder circuit 2. This decoder circuit first determines whether the transmitted, standard-compliant data stream in its address part contains an address that is assigned to the particular radio pager. A pager usually more, for example four, addresses are assigned, under which he is separately addressable and under which separately cacheable messages to the pager are sendable. If the address preceding the message does not correspond to an address of this pager, the message is ignored. If the address corresponds to one of the call receiver addresses, the associated message is stored in the corresponding buffer memory 30-33. For presentation reaches a stored message on the display panel 3. This is formed for example by an LCD display element with 32 x 100 display elements. On this display element four lines of text are shown in the prior art. The message consists of a series of 7-bit binary words, each of which corresponds to a letter or other characters. These binary words are applied by the decoder circuit 2 as an address to a font memory (ROM) 4. This memory outputs as data the dot matrix representation (eg 5x7 dot matrix representation) of the corresponding letter to the display field 3. Via a control line 6, the decoder circuit 2 causes the corresponding juxtaposition of the letters in the four lines of the display panel.

CH 683 052 A5

Only characters (letters, numbers, punctuation marks, special characters) whose assignment 7-bit code to 5 χ 7 - dot matrix representation have been previously stored in the ROM can be represented.

In the following, first the method for transmitting long messages will be explained with an example. A long message is a message that is longer than a message that can be transmitted by the network operator in a transmission cycle. The system operator limits the maximum length of messages that can be entered into the network for a number of reasons, in particular so as not to reduce the quality of the paging service to other users and to avoid reception reliability issues when sending long messages.

When solving the problem, it should be noted in addition to the maximum length of the message that the amount of permitted alphanumeric characters in the system is also limited by the network operator. However, special codes must be entered into the system in such a way that they are not rejected as inadmissible. It should also be noted that the order in which messages are received by the pagers is unknown when entering messages into the system.

In order to send a long message, therefore, in the invention, this long message is separated into system-acceptable single messages which are sent by the system as completely independent single messages to the pager (s) intended for it. In the respective pager, for example, a subaddress is specified as the address for receiving long messages. To assemble the individual messages arriving at the pager in random order to the long message, each part of the message is provided with an addition; Message part and addition each form the coming to the transmission of individual message.

Preferably, three characters of 7 bits, that is 21 bits, are used as an addition to each message part. The addition is prefixed to the message part as a header, for example.

So that conventional paging networks accept this addition, the most significant bit (MSB) is selected as 1 in each case. In the following illustration, the least significant bit (LSB) is specified first. The addition is preferably structured as follows:

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where the bits are defined as follows:

X1 and X2

X3, X4, X5 X6, Y1, Y2, Y3

For the present embodiment, each 0; other combinations can be selected for special functions.

Defining a sequence number 0-7.X3 is the LSB

Define the number of blocks of 20 characters transmitted in each individual message. X6 is the LSB.

Y4, Y5, Y6, Z1, Z2, Z3, Z4, Z5, Z6 Define the number of blocks of 20 characters in each

Single message and the following single messages belonging to the long message. Numbers from 1-512 are used. Y4 is the LSB.

Transfers are preferably made only in full blocks of 20 characters. Space characters are used to fill a block if necessary. Long messages of up to 10 240 characters can be transmitted in this way.

For example, the following message is sent to a pager or group of pagers:

Orange juice wants to raise by 25%

This message is 124 characters long. In the Swiss paging network, such a message has not yet been transmitted, since the maximum message length is 80 characters.

The message is now split into two parts:

Part a Afler the failure of the orange harvest in florida, it is expected that the p

Part B rice of January orange juice wants to raise by 25%

Part a consists of 77 characters and is now supplemented with the addition of 3 characters (7 bits each). The individual message consisting of part and additional (header) contains a maximum of 80 characters. If the individual message is the sixth message to the pager, it receives the sequence number 6 or binary 011 (LSB as the first bit). Part a consists of 80 characters including the header, and therefore the number of blocks of 20 characters transferred in the single message is 4, binary 0010.

Part b consists of 47 characters, so three blocks of 20 characters, including spaces to refill; therefore, in addition to part a, the number of transmitted blocks plus the following will be added

Blocks indicated as 4 + 3 = 7, binary 111 000 000.

CH 683 052 A5

The head for part a is thus as follows:

X1 X2 X3 X4 X5 X6 1 Y1 Y2 Y3 Y4 Y5 Y6 1 Z1 Z2 Z3 Z4 Z5 Z6 1 000110101011110000001

6 4 7

X z ü in Switzerland, this 3 χ 7-bit string is transmitted as X z ü as already shown above. For the part b, consisting of 47 characters, 3 blocks of 20 characters are used. This single message is followed by no further individual message belonging to the overall message. The sequence number for the long message is 6. The header for part b is therefore as follows:

X1 X2 X3 X4 X5 X6 1 Y1 Y2 Y3 Y4 Y5 Y6 1 00011111001101 0 6 3 3

Z1 Z2 Z3 Z4 Z5 Z6 1 0 0 0 0 0 0 1

In Switzerland, this head is transmitted as x ç ü as indicated above.

The completely independently transmitted individual messages A, B are therefore:

It is expected that the p

B xçürice of January orange juice wants to raise by 25%

Even if the pager receives message B before message A, he can see from the heads that A and B are parts of the same long message, and that A belongs before B. Repetitions of the individual messages A and / or B also pose no problems for the pager since the individual messages can always be logically correctly assigned to the overall message.

Fig. 3 shows an embodiment of a pager. In this case, 1 again denotes the receiver circuit. 40 denotes a data processing circuit or decoder circuit. The decoder circuit is now designed to decode the first three characters of each individual message addressed to the predetermined subaddress as a header, and to respectively store and display the individual messages. The decoder circuit 40 is connected directly to the display panel 3 via the data line 35 in this example. It will now be explained a preferred aspect of the invention, according to which messages are transmitted pixel by pixel, resulting in large amounts of data or very long messages, which are separated according to the invention in individual messages. A message, for example the image shown in FIG. 4, is transmitted pixel by pixel according to the invention. At the transmitter side, the image of the message, be it a pure text or, as shown, an image and text message, is decomposed into a number of pixels which corresponds to the number of pixels of the display field 3 of the paging receiver. Each pixel is assigned the binary value 0 or 1, according to the state OFF or ON (LCD element) or LIGHT or DARK (visual impression) of the respective pixel. The so in the pixel or A bit-decomposed message is addressed to a paging receiver and transmitted bit by bit as a plurality of 80-character single messages. The paging receiver has, for example, the display panel 3 shown in FIG. 4 with 32 × 100 pixels. Preferably, the image structure is on the send and receive side by line, with one line each 2 times four pixels high. These 2 by 4 pixels can each be transmitted as a 2 χ 4-bit binary word; For a line thus 100 2 x 4-bit binary words are transmitted. In order to obtain full compatibility with the previous data formats in a paging network, the individual 2 χ 4-bit words are each preferably added to 2 χ 7-bit words, eg the 4-bit word 1111 to 0001111. The 16 possible 4-bit words from 0000 to 1111 thus represent the characters 0 to 9, space, U, [,] and "spare" in the 7-bit code. Starting in the first line in the upper left corner of the representation of Fig. 4 is the transmitted binary sequence, for the sake of simplicity without supplementing 7 bits, 0000 0000/0001 0010/1000 ...... etc., until the first line is transmitted (the activated pixels are shown in Fig. 4 only as outlined box). Then the second line with the binary words 0000 0010/0010 0100/0000 1000 / .... etc. is transmitted. The follow

Lines 3 to 4 in the same way. In the presentation of the thus transmitted message in the radio pager, the decoder circuit 40 via the control line 6 to the display panel 3 ensures that each is incremented within the line and line by line. About the 4-bit data line 35 are the

CH 683 052 A5 relevant bits of the 7-bit binary words are applied to the display field in order to activate the corresponding pixels. In the manner mentioned, it is possible to send any images and texts to a pager. It can be seen, however, that more information has to be transmitted than in the transmission of the prior art. There, a 7-bit word is sufficient for the transmission of a letter, in the described method, the letter must be transmitted pixel by pixel with a variety of 7-bit words. For lightly polled paging networks this poses no problems. So it is quite conceivable, a little polluted paging network, ie one with a few participants, in which also only expensive codable characters are used (eg Chinese, Thai or Cyrillic characters) to operate based on this pixel-by-pixel transmission. For heavily used networks, the necessary long transmission time can be problematic.

Preferably, therefore, both types of transmission are optionally provided switchable. Alphanumeric texts using only characters of a font memory in which a basic set of characters is encoded are transmitted encoded in a known manner. If special characters are to be displayed which are not contained in the character set memory, the system switches over to the described pixel-by-pixel transmission and transmits them point by point.

Fig. 5 shows schematically a paging receiver 19 with a corresponding structure. To the receiver circuit 1 includes a decoder circuit 41 with latches. The decoder circuit on the one hand has a control output for the row control of the display panel 3, which is connected via the control line 6 to the display panel. On the other hand, a control output and a control line 7 are provided for a switching arrangement 43, which is arranged in the data line. In the one position of the switching arrangement, the received bit words arrive as addresses to the font memory 4. This gives the predetermined, stored character representations via line 34 to the display panel. In the other position of the switching arrangement, the bit words go directly to the display field to activate individual pixels.

There are two options for switching between transmission types. On the one hand, the transmission type can be permanently assigned to an address of the radio paging receiver. Thus, for example, two of the four addresses of the radio paging receiver can be reserved for the pixel-by-pixel transmission. If the radio paging receiver is addressed at one of these two addresses, the switching arrangement 43 and the display panel 3 are controlled accordingly by the decoder circuit. The font memory 4 remains unused. If the pager is addressed on one of the other two addresses, the switching arrangement is switched over, such that the received bit words reach the character set memory 4 and whose output signals control the display field 3 via line 34. Accordingly, the line connection of the display panel 3 is influenced via the control line 6, so that control in one case, the successive 7-bit words each in a row adjacent, 2 times four pixels high columns of the display panel, in the other case, however, each in a row adjacent 5x7 dot matrix fields.

The other possibility of switching between the transmission and display modes is that switching within a message. This allows optimal utilization of the advantages of both types of transmission. For standard characters (eg, the usual Latin letters and numbers) within the message, the font memory is used.

In the message but now any special characters may be present, which have no equivalent in the font memory. When such a character occurs, it is switched to the pixel-by-pixel transmission, the decoder circuit 41 drives the switching arrangement to give the relevant bits of the 7-bit words to the display panel, and the special character is built up from individual pixels. Thereafter, the switch back to character set transfer. Switching from character set transfer to pixel transfer can be triggered by a predetermined 7-bit binary word since not all possible 7-bit words are needed for the record transfer. If the predefined 7-bit word, which does not represent a symbol that can be represented, is detected by the decoder circuit as a switching signal to bi-point transmission. Since this type of transfer requires all possible 2 x 4-bit words, the return to character set transfer can not be triggered by a 4-bit word. The return switching is therefore carried out so that it is done automatically by the decoder circuit after a predetermined number of 2 x 4-bit words (eg after ten 2 x 4-bit words).

Since there are several free 7-bit words in the code, many of these words can be used as toggle words, with each 7-bit toggle word corresponding to a different number of 2 x 4-bit words to return. This allows a flexible switching time depending on the complexity of the character to be represented pixel by pixel. Fig. 6 shows the pixel-by-pixel structure of the character ü. The corresponding 4-bit words are 0111 1110/1000 0010/0000 0010/1000 0010/0111 1110. When transmitted as 7-bit words, the representation of the ü is transmitted pixel by pixel as a string&gt; 71 4041 4&gt; 7.

In the three preceding bits, at most additional information can be transmitted, eg color information in the case of a multicolor display element 3. In the transmission of graphics, such as shown in Fig. 4, a plurality of individual representations can be further transmitted when the pager with sufficient Storage space is equipped. If these representations are then read out from the memories in quick succession and displayed on the display, a moving image can be displayed.

CH 683 052 A5