KR950007494B1 - The message transmitting and receiving method of paging system - Google Patents

Abstract

To send paging data, the method sends Hangul, English, number and symbol message to page receiver efficiently. This paging system consists of two steps: the first step sets prescribed dummy bits to address code word, message code word, synchronization code word and idle code word following POCSAG code type consisting of 32 bit; the second step sends overall code word excluding dummy bits.

Description

How to Send and Receive Messages in Paging Systems

1 is a block diagram of a conventional POCSAG code.

2 is a block diagram of a conventional codeword.

3 is a block diagram of a conventional numeric message codeword.

4 is a codeword configuration diagram for explaining the application of Hangul message code to the codeword of FIG.

5 is a configuration diagram of an address codeword according to the present invention.

6 is a block diagram of a message codeword when sending a Hangul message according to the present invention.

7 is a block diagram of a message codeword in English, numeric and symbol message transmission according to the present invention.

8 is a block diagram of a synchronous codeword according to the present invention.

9 is a block diagram of an idle codeword according to the present invention.

10 is a flowchart of a message receiving process according to the present invention.

11 is a flowchart of a message transmission process according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transmitting and receiving messages in a paging system. In particular, a page station to which a fixed station for transmitting paging data is subscribed can efficiently transmit Korean, English, numbers, and symbolic messages. The present invention relates to a message transmission and reception method of a paging system that enables a receiver to efficiently receive Korean, English, numeric and symbolic messages from a fixed station.

In the current paging system, a POCSAG code (Post Office Standardization Advisory Group) constructed by BCH (Bose Chaudhri Hocquegham) theory is used to send a message from the station to the subscribed page receiver. POCSAG code is used as a code for transmitting numeric and alphanumeric data. The conventional POCSAG code is constructed as shown in FIG. As can be seen in FIG. 1, the transmission of a code starts from a preamble and then each codeword batch is transmitted. The preamble consists of 576 bits, each codeword group consists of 544 bits including a sync code (SC) and eight codeword frames, and one codeword frame consists of two codewords.

Codewords included in each codeword group are divided into four types: a sync codeword, an address codeword, a message codeword, and an idle codeword. The conventional sync codeword is composed of 32 bits (b1-b32) as shown in Fig. 2A, and the conventional address codeword is made as shown in Fig. 2B. Bit 1 of the address codeword is always 0 and used as an identification bit to distinguish it from the message codeword. Address bits are allocated from bits 2 to 19, b19. . Bit 20 (b20) and Bit 21 (b21) are allocated as function bits for selecting four types of ring tones, and Bits 22 through 31 are allocated as parity check bits. The first bit b32 is allocated as an even parity bit. Of the 21 bits of address bits, 3 bits of LSB (Least Significant Bit) are not transmitted but are used for frame division. Therefore, more than 2 million call numbers (ID numbers) can be allocated when 18 bits of address bits are actually transmitted. The conventional message codeword is constructed as shown in (c) of FIG. 2, where bit 1 (b1) is always " 1 " to be used as an identification bit for discriminating from an address codeword, and bit 2 ( Bits b2) to bit 21 (b21) are allocated as message bits, bits 22b to 31b (b31) are allocated as parity check bits, and bit 32 (b32) is allocated as even parity bits. . In the message bit area of bit 2 (b2) to bit 21 (b21), 5 numbers can be accommodated in the case of a numeric message, and 2x6 / 7 characters can be accommodated in the case of an alphanumeric message. The conventional idle codeword is configured as 32 bits as shown in Fig. 2D.

A numeric message takes 4 bits per character, and as shown in Fig. 3, it is possible to send exactly 5 characters in the message bit area of 20 bits in the message codeword, but Hangul messages take 16 bits per character. In this case, 1.25 characters can be sent in one message codeword. In this case, 4 bits out of 20 bits of the message bit area remain as shown in FIG. When sending Korean message with 4 bits left, the transmission efficiency decreases, and when Korean message is put in succession, it is very complicated not only in the composition of the transmission code but also in decoding the received Korean message on the pager receiver. As the processing speed is considerably slowed down, and the Korean, English, numbers, and symbol messages are mixed and transmitted, the pager receiver cannot efficiently receive Korean messages because it is more complicated to decode. There was a problem that can not provide Hangul messages to subscribers.

The present invention has been made in view of the above-described problems, and the paging system can efficiently transmit Korean, English, numeric and symbolic messages to the pager receiver, and the pager receiver can display Korean, English, numeric and An object of the present invention is to provide a method of transmitting and receiving a message of a paging system that can efficiently receive a symbol message.

In order to achieve the above object, the present invention provides a message transmission method of a paging system, wherein a 32-bit POCSAG code type address codeword, a message codeword, a sync codeword, and an idle codeword have dummy bits of a predetermined number of bits. First step of setting; And a second process of transmitting an address codeword, a message codeword, a sync codeword, and an idle codeword consisting of bits other than the dummy bits in units of bits.

The present invention also provides a first process for receiving a codeword including an address codeword, a message codeword, a sync codeword, and an idle codeword in units of bits; A second step of checking whether the codeword has been received by a predetermined number of bits; A third step of returning to the first step when the codeword is not received by the predetermined number of bits in the second step; A fourth step of constructing a 32-bit POCSAG code type codeword by adding dummy bits of a predetermined number of bits to the received codeword when the codeword is received by a predetermined number of bits in the second step; A fifth step of detecting an error of the codeword configured in the fourth step; A sixth step of using the codeword when no error is detected in the fifth step; A seventh step of checking whether an error bit number is greater than or equal to a predetermined bit when an error is detected in the fifth step; An eighth step of correcting an error of the codeword if the number of error bits is not more than a predetermined bit in the seventh step; A ninth step of determining whether the received codeword is a paging data codeword when the number of error bits is greater than a predetermined bit in the seventh step; A tenth step of using or ignoring the corresponding codeword when the codeword is determined to be a paging data codeword in the ninth step; In the ninth step, if the codeword is not determined to be a paging data codeword, an eleventh step of disregarding the codeword is provided.

By this method, the present invention can efficiently transmit and receive Korean, English, numeric and symbolic messages, and the address codeword, message codeword, sync codeword and idle codeword of the conventional POCSAG code are 32 bits each. Although the address codeword, message codeword, sync codeword, and idle codeword according to the present invention are shortened by 4 bits each to 28 bits, the message processing time is 12.5% (4 bits / 32 bits × 100 = 12.5). As shortened.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a configuration diagram of an address codeword according to the present invention, and FIGS. 6 and 7 are configuration diagrams of a message codeword according to the present invention, and FIG. 8 is a configuration diagram of a synchronization codeword according to the present invention. 9 is a configuration diagram of an idle codeword according to the present invention, FIG. 10 is a flowchart of a message reception process according to the present invention, and FIG. 11 is a flowchart of a message transmission process according to the present invention. As shown in (a) of FIG. 5, the address codeword is allocated to the address flag as the first bit b1, and the second bit b2 to the fifteenth bit b15 are allocated to the address bit area. Bits b16 through 19b b19 are allocated as dummy bits, bits 20b and 21b are allocated as function bits, and bits 22b to 31 are allocated. The first bit b31 is allocated as a parity check bit, and the 32 bit b32 is allocated as an even parity bit. When address data is sent from the fixed station to the pager receiver, only 28 bits are sent out, except for the dummy bits 16 bits (b16) to 19 (b19) as shown in (b) of FIG. In this case, since sufficient call numbers of 2 ¹⁷ (131,072) can be allocated except for the function bits, sufficient subscribers can be set so that there is no problem in operating an actual paging system.

As shown in (a) of FIG. 6, the message codeword in the transmission of the Hangul message is allocated with the message flag, and bit 1 (b1) is assigned to the message flag, and bit 2 (b2) to bit 17 (b17) is the Hangul message. Bit 2 (b2) is assigned to the area and Hangul display flag is allocated, bit 18 from bit 18 to bit 21 from bit 21 is allocated as dummy bit, bit 22 from bit 22 to bit 31 from b31. Up to 32 bits are allocated as parity check bits, and bit 32 (b32) is configured as an even parity bit. When sending a Hangul message from the fixed station to the pager receiver, only 28 bits are transmitted except the dummy bits of bits 18 to 21 (b21), as shown in (B) of FIG. Bits b3 through bits 7 to b7 are initial, bits 8 to b12 to neutral in the area b12, bits 13 to b17 to bit 17 Hangul messages appear in the order of the finality in the area up to.

As shown in (a) of FIG. 7, the message codeword when transmitting an English, numeric, and symbolic message is allocated bit 1 (b1) to the message flag, bit 2 (b2) and bit 10 (b10). ) Are allocated to the English display flag, and bits 3 to 9 are assigned to the English message area, bits 11 to 17 to bits 17, and bits 18 to 18. ) Bits 21 to b21 are allocated as dummy bits, bits 22b to 31b are allocated as parity check bits, and bits 32b to 32 are allocated as even parity bits. In case of transmitting English, numeric and symbol message from fixed station to pager receiver, only 28 bits are transmitted except dummy bits of bit 18 (b18) to bit 21 (b21) as shown in (b) of FIG. In the English message area, English, numeric and symbolic messages consisting of 7-bit ASCII code are displayed.

As shown in (a) of FIG. 8, the sync codeword is allocated to the sync code area from bit 1 (b1) to bit 17 (b17), and bit 18 (b18) to bit 21 (b21). Up to 32 bits (b22) to 31 (b31) are allocated to the parity check bit area, and 32 bits (b32) are configured by assigning even parity bits. When the synchronous codeword is transmitted from the fixed station to the pager receiver side, only 28 bits are transmitted except the dummy bits of bits 18 to 21 (b21) as shown in (b) of FIG.

As shown in (a) of FIG. 9, the idle codeword is allocated to the idle code area from bit 1 (b1) to bit 17 (b17), and bit 18 (b18) to bit 21 (b21). Up to 32 bits (b22) to 31 (b31) are allocated to the parity check bit area, and 32 bits (b32) are configured by assigning even parity bits. When the idle station transmits an idle codeword from the fixed station to the pager receiver side, only 28 bits are transmitted except the dummy bits of bits 18 to 21 (b21) as shown in (b) of FIG.

In the above description, dummy bits are set to 4 bits in each of the address codeword, message codeword, sync codeword, and idle codeword, and 28 bits other than 4 bits dummy bit are transmitted during actual transmission, but the present invention is not limited thereto. The number of bits of the dummy bit can be added or decreased within the range in which the Hangul message can be transmitted.

The pager receiver includes the 28-bit address codeword as described above (see (b) in FIG. 5), the 28-bit message codeword (see (b) in FIG. 6) when transmitting Korean messages, alphanumeric characters and symbols. 28-bit message codeword (see (b) in Figure 7), 28-bit synchronous codeword (see (b) in Figure 8), and 28-bit idle codeword (see (b) in Figure 9) at the time of message transmission. By receiving the paging data consisting of a Korean message, an English message, a numeric message and a symbol message can be efficiently received.

When the fixed station transmits Korean, English, numeric and symbolic messages to the pager receiver side, it transmits them in the order shown in FIG. First, the fixed station sets 4-bit dummy bits in an address codeword, a message codeword, a sync codeword, and an idle codeword composed of 32 bits by a BCH code scheme (POCSAG code scheme), and then includes an address codeword composed of the corresponding 32 bits, After the dummy bit is excluded from the message codeword, the sync codeword and the idle codeword, an address codeword consisting of 28 bits excluding the dummy bit (see (b) of FIG. 5) and a message codeword ((b) of FIG. 6). (B) in FIG. 7, a sync codeword (see (b) in FIG. 8), and an idle codeword (see (b) in FIG. 9) are transmitted in bit units to the pager receiver.

When the pager receiver receives Korean, English, numeric and symbolic messages by receiving 28-bit codewords (address codewords, message codewords, sync codewords, and idle codewords) from the fixed station, as shown in FIG. Receive in order. That is, when the pager receiver receives each codeword bit by bit from the fixed station and determines that all 28 bits have been received, the full 32-bit BCH code is added by adding 4 bits of dummy bits to the received codeword. Constitute a word (POCSAG codeword). If there is no error in the received codeword, if there is no error, the received codeword is used as it is, and the next operation is performed. If there is an error in the received codeword, it is determined whether the error is less than 3 bits. Is less than 3 bits, corrects the error of the received codeword, uses the error-corrected codeword, and executes the following operation. If the error is more than 3 bits in the received codeword, it is determined whether the received codeword is a paging data codeword.If the received codeword is not a paging data codeword, the received codeword is ignored and the next operation is executed. In the case of a paging data codeword, the received codeword is used as it is and the next operation is performed when it is determined whether or not the received codeword is used. In the above description, a dummy bit is set to 4 bits in each of an address codeword, a message codeword, a sync codeword, and an idle codeword, and a 4-bit dummy bit is added to each 28-bit codeword received upon actual reception. A BCH codeword (POCSAG codeword) is configured, but is not limited thereto. A complete BCH codeword (POCSAG codeword) is obtained by adding or subtracting the number of bits of a dummy bit to a received codeword within a range capable of receiving Korean messages. Can be configured.

Claims (2)

CLAIMS 1. A message transmission method of a paging system, comprising: a first step of setting a predetermined number of dummy bits in an address codeword, a message codeword, a sync codeword, and an idle codeword of a 32-bit POCSAG code method; And a second step of transmitting an address codeword, a message codeword, a sync codeword, and an idle codeword consisting of bits other than the dummy bits in units of bits. A first step of receiving a codeword including an address codeword, a message codeword, a sync codeword, and an idle codeword in units of bits; A second step of checking whether the codeword has been received by a predetermined number of bits; A third step of returning to the first step when the codeword is not received by the predetermined number of bits in the second step; A fourth step of constructing a 32-bit POCSAG code type codeword by adding dummy bits of a predetermined number of bits to the received codeword when the codeword is received by a predetermined number of bits in the second step; A fifth step of detecting an error of the codeword configured in the fourth step; A sixth step of using the codeword when no error is detected in the fifth step; A seventh step of checking whether an error bit number is greater than or equal to a predetermined bit when an error is detected in the fifth step; An eighth step of correcting an error of the codeword if the number of error bits is not more than a predetermined bit in the seventh step; A ninth step of determining whether the received codeword is a paging data codeword when the number of error bits is greater than a predetermined bit in the seventh step; A tenth step of using or ignoring the corresponding codeword when the codeword is determined to be a paging data codeword in the ninth step; And the eleventh step of disregarding the codeword when the codeword is not determined to be a paging data codeword in the ninth step.