KR100295397B1 - Method of Designating Multiple Time Slots of Reverse Radio Link for Bidirectional Radio Paging System - Google Patents

Abstract

The present invention relates to a time slot designation method of a bidirectional radio call reverse radio link, and more particularly, to a method for designating a time slot for transmitting a message corresponding to a single or a plurality of packet lengths within a unit cycle.

According to the present invention, a transmission message is divided into a connectionless packet using a single unit packet and a transmission message using a plurality of unit packets by connecting a plurality of unit packets. In the case of a slot connectionless packet, a wireless call terminal sends the message as a single packet. And determining the timeslot location for transmitting the packet, then transmitting the packet to the timeslot location.

In the case of a slot-connected packet, the number of packets required for transmitting the message is calculated, the timeslots are allocated as many times as the number of packets required, and the messages are combined to form a single packet. The packet is transmitted using timeslots corresponding to the required number of packets.

In addition, in the case of the reservation-connected packet and the connectionless packet, the radio call terminal is characterized in that the step of the packetized the message, and transmitting the packet to the time slot position.

Description

Method of designating multiple time slots of reverse radio link for bidirectional radio paging system

The present invention relates to a time slot designation method of a reverse radio link for a two-way radio calling system. Particularly, in the case of the S-ALOHA region, an address of a radio call terminal for address allocation can be reduced so as to reduce the probability of collision due to traffic distribution. In the case of a transmission message corresponding to a plurality of packet lengths in one cycle, the synchronization signal is present only in the first packet in a cycle, thereby improving channel efficiency. The present invention relates to a time slot designation method of a radio link.

A unidirectional radio call communication system generally consists of one or more switching and central control units, a base station facility, and a unidirectional radio call terminal. Because of the characteristics of the system, since the wireless calling system terminates after performing one-way transmission, the one-way wireless calling system was able to provide a service using only a relatively simple system. It is becoming more sophisticated and complicated due to the expansion of.

In a one-way wireless paging system, a pager user dials a wireless subscriber number and is sent to a central control unit, usually called a wireless calling terminal, through a local exchange, and checks the registration of the subscriber in the database. Coded by the unique number of the radio receiver, it transmits through the transmitter and informs the caller of the fact.

The central control unit makes a call request input from a public switched telephone network (PSTN) according to the registration data for subscriber inquiry, service menu inquiry, etc., and generates a radio call signal corresponding to the received signal to the transmitting station. It performs the function of sending a signal.

In the case of the Post Office Code Standardization Adversary Group (POCSAG), which currently occupies the absolute market of wireless calling, the transmission rate is generally 1,200bps (1200 bits per second), and it is difficult to provide various services at such transmission rates. In particular, in the case of text transmission and data transmission, a number of data transmission is required in the case of a number transmission using a BCD code, thereby limiting subscribers accommodated at the same frequency. A high-speed wireless calling method has been proposed to solve this problem.

Examples include Flex (FLEXible) developed by Motorola, European Telecommunicaion Standard Institute (ETSI), European Radio MEssage System (ERMES) and APOC developed by Philips. Advanced Paging Operators Code).

However, this method is also a one-way dedicated service, and it has a problem in that it cannot confirm whether a wireless call terminal is received with respect to data transmitted by a wireless call system, and cannot accept a service request of a wireless call terminal. In addition, the subscriber of the wireless calling terminal cannot check what message is in the case of error in part or all of the data even though the predetermined data is transmitted, and the sender of the message considers that the predetermined message is properly delivered. In the following actions, there was a problem that often the wireless communication between the two does not occur correctly.

In order to solve this problem, two-way radio calling has appeared, and the characteristic of two-way radio calling is different from the current one-way radio calling method such as POCSAG or FLEX. can do. That is, whether the message transmitted by the wireless call system arrives correctly can be confirmed through the response from the wireless call terminal.

Looking at the currently developed two-way radio calling, there are ReFLEX, which enables two-way communication by supplementing some functions of FLEX in Motorola, NexNet developed by NEXUS of Israel, and pACT based on CDPD of AT & T. It is not commercially available.

Aloha method that does not require a separate control channel in the radio calling system reverse radio link is applied, and time slots that are synchronized in time to accommodate multiple subscribers at a limited transmission rate can be allocated and used jointly. It was. Therefore, in order to minimize collisions between signals occupying slots, it is necessary to distribute traffic by using different slots, but in the R-ALOHA area, some collisions can be prevented by allocating timeslots in the paging system. In the case of the S-ALOHA region, there is a problem that it is impossible to reduce the probability of collision due to traffic distribution because timeslot allocation is impossible. In addition, since the conventional two-way radio call communication system is defined only for a single packet when transmitting a message in the S-ALOHA method in the reverse radio link, it is difficult to transmit long messages MSG1 and MSG2, and as shown in FIG. Since Sync) is duplicated for each packet, there is a problem that channel use is inefficient.

Accordingly, the present invention has been made in view of the problems of the prior art, and its object is to use the address of the wireless calling terminal itself for time slot assignment so as to reduce the probability of collision due to traffic distribution in the case of the S-ALOHA region. In the Aloha method of a concatenated packet having an effect of increasing channel efficiency by configuring a synchronization signal to exist only in the first packet when a transmission message corresponding to a plurality of packet lengths transmits a long message in one cycle. To provide a time slot designation method.

1A is a schematic block diagram showing a two-way wireless paging communication system to which the present invention is applied;

1B is a cell configuration of a forward radio link in a bidirectional radio call communication system to which the present invention is applied, and a point paging channel for transmitting radio call information only to a base station where a terminal is located and all base stations within a service range. Diagram showing the frequency allocation of the broadcasting paging channel (Broadcast Paging Channel) for simultaneously transmitting radio call information,

1C is a block diagram showing a reverse cell configuration and frequency allocation of a two-way wireless paging communication system to which the present invention is applied;

2 is a view for explaining the structure of the forward and reverse radio link for explaining the two-way radio call protocol of the two-way radio call communication system according to the present invention;

3 is a flowchart illustrating a time slot designation method of a reverse radio link according to the present invention;

4A is a time slot configuration diagram illustrating a conventional timeslot designation method;

4b is a time slot configuration diagram illustrating a time slot designation method according to the present invention;

FIG. 5 is a detailed configuration diagram of the connection type packet shown in FIG. 4B;

6 is a detailed block diagram of a connectionless packet,

7 is an explanatory diagram for explaining a method of designating a connection type packet.

(Code description for main part of drawing)

1a-1e; Wireless terminal

2a-2e, 2a1-2e1; Receiver 3a-3e; Peripheral base station

4a-4i; Cell 5; Wireless Call Terminal

6; Public network switch 7; PSTN Network

8a; Internet 8b; Internet server

9a; Telephone 9b; Facsimile

9c; Personal computer 100; S-ALOHA area

200; R-ALOHA area

In order to achieve the above object, the present invention provides a time slot designation method of a reverse radio link in a two-way wireless paging communication system including one wireless paging system and a plurality of wireless paging terminals. Selecting a basic packet position of a packet to be transmitted, determining whether the packet to be transmitted is a connected packet or a connectionless packet, and if the determination is a connected packet, the packet length to be transmitted, the primary packet length, and the secondary packet. Determining the total number of packets to be transmitted using the length, determining whether (total number of packets to be transmitted + current packet position-1) is larger than the maximum number of packets that can be specified, and determining the result: (total number of packets to be transmitted + current) Packet position-1) is greater than the maximum number of packets that can be specified, starting from (maximum number of packets that can be specified-the total number of packets to be transmitted + 1). And specifying the packet with the result of the determination, and if the determination result (total number of packets to be transmitted + current packet position-1) is equal to or smaller than the maximum allowable number of packets (current packet position-total number of packets to be transmitted +1) is zero Determining whether the value is less than or equal to (0) and, if the determination result (the current packet position-total number of packets to be transmitted +1) is less than or equal to zero, specifies packets sequentially from the lowest packet, and vice versa. In this case, the present invention provides a method for designating a time slot of a reverse radio link, comprising: sequentially specifying packets from (current packet position- {total number of packets to be transmitted / 2} +1).

The total number of packets to be transmitted is obtained according to the following equation.

Total number of packets to send = {(packet length to be sent-1st packet length) / 2nd packet length} + 1 (where {} applies rounding)

In addition, the current packet position can be obtained according to MOD (capcode extraction value, maximum number of packets that can be specified).

Furthermore, the capcode extraction value is obtained according to (capcode setting value) AND (mask bit value), and the capcode setting value excludes the last n bits from its address corresponding to n in the number of forward 2 ⁿ frames. The remaining bit is extracted and the mask bit value is determined according to the transmission speed.

The maximum number of packets that can be specified is determined by an area classification code value (BP) received through the forward radio link.

If the determination result is a connectionless packet, it is designated as the current packet position, and if the determination result is a reserved connectionless packet, the system is designated through a forward radio link.

In this case, the reserved unconnected packet is sequentially assigned a packet number to the last packet with the area classification reference value of each cycle as '0', and the reserved single packet number is set as (area classification reference value + system setting packet number). .

As a result of the determination, in the case of a slot connectionless packet, the packet number is designated as a (capcode extraction value) MOD (area division reference value).

According to another aspect of the present invention, in a time slot designation method of a reverse radio link of a two-way radio call communication system including one radio call system and a plurality of radio call terminals, a transmission rate and a region classification code through a forward radio link Receiving a value, determining the total number of packets to be transmitted according to the message length to be transmitted, and then packetizing the packet, using cap code settings extracted to avoid collision with a mask bit value determined according to the transmission speed. Obtaining a code extraction value, obtaining a finally assignable number of packets based on the region classification reference value, obtaining a packet position from them, and transmitting a packet to the obtained packet position. Provides a method for specifying timeslots.

According to the present invention, a time slot designation method of a reverse radio link in a two-way wireless paging communication system including at least one wireless paging system and a wireless paging terminal may be performed by the paging terminal using a single message when the wireless paging system is a slot connectionless packet. Packetizing, determining a timeslot position for transmitting the packet, and transmitting the packet at the determined timeslot position.

Calculating the number of packets required to transmit the message in the case of a slot-connected packet, single packetizing the message using the number of packets required by the required number of packets, and determining a time slot position to be transmitted; And transmitting the packet using timeslots corresponding to the required number of packets.

In the case of a reserved connection type packet or a non-connection type packet, the radio call terminal may be configured to single packetize the message and transmit the packet to the timeslot location.

As described above, in the present invention, when a time slot is designated in the Aloha method of a connected packet, a synchronization signal exists only in the first packet when a transmission message corresponding to a plurality of packet lengths transmits a long message in one cycle. It was intended to have an effect of increasing the efficiency.

(Example)

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

1A is a schematic block diagram illustrating a two-way radio call communication system according to the present invention, and FIG. 1B is a configuration of a forward cell and a frequency of a point call channel / broadcasting call channel of the bidirectional radio call communication system according to the present invention. Figure 1c is a block diagram showing the assignment, Figure 1c is a block diagram showing the configuration of the reverse cell and the frequency allocation of the two-way radio communication system according to the present invention, Figure 2 illustrates a bidirectional radio call protocol of the two-way radio call communication system according to the present invention 3 is a flowchart illustrating a time slot designation method of a reverse radio link according to the present invention, and FIG. 4A is a time slot configuration diagram illustrating a conventional time slot designation method. 4b is a time slot configuration diagram illustrating a time slot designation method according to the present invention, and FIG. 5 is a detail of FIG. 4b. Report, 6 is a detailed block diagram of the Connectionless Packet FIG.

(Two-way radio call communication system)

First, referring to FIG. 1, in the two-way radio call communication system to which the present invention is applied, one or more base stations 3a and 3b are distributed in a predetermined service area, and each of the neighbor base stations 3a and 3b is wired to a plurality of receivers. (2a, 2b), and the peripheral base station (3a, 3b) is connected to the other two-way radio call terminal 5 by wire.

The radio call terminal 5 is a radio call control device for controlling a connection with peripheral base stations 3a and 3b, and a public switched telephone network (PSTN) and a public switched telephone network (PSTN) connected by wire (7). Is connected to multiple telephones 9a, facsimile 9b, personal computer 9c, and voice and data communication with multiple e-mails 8b via the Internet network 8a. It consists of a radio calling terminal 5b which performs various kinds of databases.

The two-way radio call terminal 5 of the present invention transmits a message for the radio call terminals 1a-1c through a downlink radio and receives a message from the radio call terminal through a reverse radio link (uplink). ACK), by receiving a radio call terminal request message that can control the mailbox information such as the location registration response, message inquiry, deletion, retransmission, etc. of the radio call terminal is made bidirectional wireless communication.

(Forward cell configuration)

FIG. 1B is a diagram illustrating a configuration of a forward cell and frequency allocation of a point call channel / broadcasting call channel in a bidirectional radio call communication system according to the present invention. It is arranged to cover tightly, and is connected to the central radio call terminal (5) (3a) between them.

Peripheral base stations 3a-3i transmit message signals to radio-calling terminals 1a-1e located in their cells 4a-4i using the same frequency f0 to form broadcasting call channels, respectively. At the same time, a point call channel that selects a cell having a highest received field strength (RSSI) of a terminal and calls a terminal 1a-1e located in the cell is selected. Each cell is equipped with a transmitter for transmission using different frequencies (f0-f4).

In this case, in order to recycle the limited frequency resource, the non-adjacent cells, for example, the cells 4a and 4e, may be reallocated so that the frequency f0 may be used equally as the transmission frequency for forming the same point call channel. It is.

(Forward protocol)

In FIG. 1A, the central radio calling terminal 5 and the peripheral base stations 3a-3d are simply referred to as " systems 5 " and the system is capable of transmitting and receiving messages in forward and reverse directions every cell 4a-4i. With one transmitter and multiple receivers, the subscriber station 1 is defined as a terminal having an RF transceiver for receiving messages transmitted from the system 5 via an antenna and transmitting its own messages.

First, when the caller calls the subscriber using the telephone 9a or the computer 9c, for example, via the PSTN network 7, the radio calling terminal 5 responds to these multiple calls through a plurality of forward wireless links. The batches B0-Bn are time-division multiplexed and transmitted, each batch consisting of 16 frames (F0-F15) when 2 ⁿ , e.

In this case, each frame F0-F15 is, for example, a synchronization signal SC, a frame information signal FI, a terminal control command and called terminal address ID portion CNTL, and a plurality of message signals MSG. In this case, the wireless calling terminal 1 periodically searches only the frames of the group to which the radio call terminal 1 belongs, and performs a periodic message reception for turning off the power of the receiver during the other frame period.

According to the received message, the terminal 1 operates any one of the buzzer, the speaker, or the vibration motor according to the set incoming mode, and informs the subscriber that the message of the wireless call is received and displays the text through the indicator.

(Reverse cell configuration)

Meanwhile, FIG. 1C is a block diagram illustrating a reverse cell configuration and frequency allocation of a bidirectional radio call communication system according to the present invention. A plurality of peripheral base stations 3a-3i are arranged to cover a service area without intervening, and a central radio between them. It is connected to the call terminal 5 (3a) by the wire (2).

Peripheral base stations 3a-3i receive message signals transmitted from radio call terminals 1a-1e located in their cells 4a-4i, respectively, using the same frequency f5 to form reverse channels. A plurality of receivers (2a-2d, 2a1-2e1, ...) for each cell are provided, and each receiver (2a-2d, 2a1-2e1, ...) is a peripheral base station (3a-) located in the cell. Connected to 3e).

(Reverse protocol)

A method of transmitting a message from the radio calling terminal 1 to the radio calling terminal 5 through an uplink radio link will be described with reference to FIG. 2.

First, the number of timeslots (ie, packets) per cycle (CC) (or 1 frame) for the reverse radio link connection from the plurality of radio calling terminals 1 of the present invention is configured to increase with the transmission rate. For example, when the transmission rate is 800bps, as shown in FIG. 2, 10 timeslots (T0-T9) are configured, and when the transmission rate is 6400bps, a unit cycle is determined with a maximum of 60 timeslots.

That is, the time occupied by a single timeslot is variably applied according to the transmission rate, and the reverse rate is variably applied from the lowest 800bps. Here, a single packet is transmitted in one timeslot.

In this case, it is preferable that each cycle CC of the reverse channel is set to have the same timing as the frame to which the subscriber of the forward configuration B0 belongs, for example, the fourth frame F3. That is, the system 5 transmits timing information to the terminal 1 through the forward frame information FI, and the terminal 1 synchronizes with the corresponding frame F3 of the forward channel to time the reverse time slot. Fit.

Meanwhile, in the bidirectional radio call system according to the present invention, an uplink radio link adopts an Aloha method that does not require a separate control channel, and slot aloha determines a timeslot to be transmitted by the terminal within a unit cycle of the reverse radio link. ALOHA (hereinafter referred to as "S-ALOHA") S-ALOHA area 100 to which timeslots are allocated by protocol, and reservation aloha in which the paging system designates the timeslots to be transmitted by the paging terminal. (Reservation ALOHA: hereinafter referred to as "R-ALOHA") The protocol is divided into the R-ALOHA area 200 to which the timeslot is assigned.

That is, the ten timeslots T0-T9 included in the unit cycle CC of the reverse radio link are divided into two regions, that is, the S-ALOHA region 100 and the R-ALOHA region 200.

The S-ALOHA protocol, which allocates five timeslots T0-T4 allocated to the S-ALOHA area 100, is a protocol that considers the speed of transmission first. Each communication unit, that is, the terminal 1 is a system. It attempts to transmit its information, i.e., messages, in packet units in a reverse timeslot that is randomly selected for (5). If the selected timeslot is not occupied, the message of the terminal 1 is transmitted to the system 5. However, if a random reverse timeslot is already occupied, a collision of information (message) occurs and the transmitted information may not reach the system 5 and may require retransmission.

Meanwhile, the R-ALOHA protocol, which allocates five timeslots T5-T9 allocated to the R-ALOHA region 200, is a protocol that considers transmission stability first, based on an exclusive license assignment from the system 5. A communication protocol useful for transmitting long data messages by allocating reverse timeslots for the terminal 1.

That is, in this R-ALOHA protocol, each communication unit, i.e., the terminal 1, can reserve the reverse time slot required for the transmission of a long message requiring a plurality of data packets to the system 5 and transmit the message.

In the message transmission through the reverse radio link of the present invention, the S-ALOHA area 100 and the R-ALOHA area 200 are variably increased and operated, and the area division of the two areas is provided to the system operator of the system 5. By the traffic within the geographic cluster unit, it is designated in consideration of the importance of the speed and stability request of the transmission, and the designated zone classification code value (BDC) is notified through the forward wireless link to prevent transmission to the terminal 1 The area classification reference value BDR is obtained based on this area classification code value BDC.

(How to specify timeslot for connected packet)

Hereinafter, a method of designating a timeslot for a reverse radio link according to the present invention will be described with reference to FIGS. 3 to 7.

(1) Slot / Connection Packet Designation

As one embodiment for the present invention, the primary packet length and the secondary packet length in the concatenated packet are set as shown in Table 1 below, and the specified length may be changed according to the BDR value.

Baud rate Primary packet length (bit) Secondary packet length (bit) 800 47 130 1600 47 130 2200 67 160 6400 67 160

Since the designation of the connected packet is made within one cycle (CC), the maximum number of packets that can be specified in one cycle cannot be exceeded.

According to the transmission rate and the BDR value, the total number of packets to be transmitted is determined by Equation 1 below.

Total number of packets to send = {(packet length to be sent-primary packet length)

/ 2nd packet length} + 1 ({} is rounded up)

However, the content of {} is rounded up, and in case of a packet generated by the request of the terminal, the terminal transmits only the frame except for its own frame.

By using the total number of packets to be transmitted according to Equation 1 above, if (maximum number of packets that can be specified) <(current position + total number of packets to be transmitted-1) from the current position (A = maximum number of packets that can be specified-current position -Set the packet as much as that value by A value of 1), and designate the remaining number of packets in the future including its position as much as (current position-A value).

Specify the number of packets to be transmitted from the current position to the number of forwards.If (maximum number of packets that can be specified) ≥ (the current position + the total number of packets to be sent-1), the (B = the total number of packets to be sent-the current position + 1) If the value of B is positive, set the packet by the value of B, and specify the number of remaining packets including its position by (current position-B value + 1) .If the value of B is negative, the current position. Specifies packets from the back.

As one embodiment for the present invention, when the transmission rate is 800bps, and the BP is '00', since the total number of packets is 10, the maximum number of packets that can be specified is [total number of packets (10) / 2 + BP (0)]. The number of becomes five. In addition, the number of packets to be transmitted is numeric (PIT = 000), and if the length of the packet (PIL = 50), the actual length of the message to be transmitted is (4 x 50) bit = 200 bits.

Therefore, the total number of packets to be transmitted = {(packet length (200bit)-primary packet length (68bit) to be transmitted) / secondary packet length (130bit)) + 1 can be calculated. As a result, the total number of packets to be transmitted is determined to be three.

Using the obtained total number of packets to be transmitted, the maximum number of packets (5) ≥ the current position (3) + the total number of packets to be transmitted (3)-1) is obtained. 5)-Current position (3)-1) Since the value is '1', set it to 1 backward, and designate as much as the number of remaining packets including its position as much as (current position-A value (1)).

This is shown in the drawings as shown in FIG. That is, three timeslots T2-T4 are designated, including timeslots T2 and T4 before and after timeslot T3.

(2) Slot / Connection Packet Configuration

A connection type packet is composed of a message received in one packet, the PIT is designated to allow various forms such as numbers and letters, and the length of the entire message using PIL to form the entire message in one packet form. Specifies. If the length of the message is less than the length of one specified packet, the remaining part is added with a value of zero '0'.

(3) Slot / Connectionless Packet Designation

When set to the slot single packet transmission mode or requested by the system, the terminal calculates a packet number as shown in Equation 2 below, and transmits a message using the packet set by the calculation.

Packet number = MOD (capcode extract, BDR), where MOD (x, y) is the remainder of x divided by y

The number of slot packets is sequentially incremented to the previous bit of the area discrimination reference value, with the first packet of each cycle being '0'. The capcode extracted value is obtained as shown in Equation 3 using the capcode set value extracted to avoid collision with a mask bit value determined according to a transmission speed.

Capcode Extract Value = (Capcode Extract Value) AND (Mask Bit Value)

As one embodiment for the present invention, the mask bit value according to the transmission rate is set to 4 bits when the transmission rate (bps) is 800, 5 bits when 1600, 5 bits when 3200, 6 bits when 6400 ....

In addition, when n = 4, the total number of forward frames (2 ⁿ ) is defined as 16 frames, and the capcode setting value is the last n bits in its capcode to minimize collision between terminals having the same forward frame number. Defined as bits except 4 bits here.

For example, the slot / connectionless packet number allocation will be described below.

Slot Single Packet Transmission Mode When the area classification reference value is '2' at the transmission speed of 800bps, if the cap code of the terminal A is (1F3C4) _16, if 8 bits are extracted from the 5th bit from the LSB, '3C' = 60 If the cap code of the terminal B is (IF3B4) 16, if 8 bits are extracted from the 5th bit from the LSB, '3B' = 59. Accordingly, the terminal A has a MOD (60, 2) value of '0' and a packet number of '0', and the terminal B has a MOD (59, 2) value of '1' and a packet number. Becomes '1'.

(4) Reservation / connectionless packet designation

The reserved single packet number is assigned by the system and set through the forward radio link. The reserved single packet number is sequentially increased to the final packet with the area classification reference value of each frame as '0'.

The allocation of the reserved single packet number is calculated by the following equation (4).

Packet No. = Area Classification Parameter (BP) + System Setting Packet No. (SPNo)

On the basis of the cycle number (ie, NB = 0) at the time when the paging system allocates the reserved slot for the paging terminal, the cycle number at the time of the system designation and the terminal at the time specified by the system are designated. If the cycle number at the time of transmission is the same, it is set to NB = 0. If the terminal is designated as the time to transmit in the next cycle based on the cycle number at the time of the system designation, it is set to NB = 1. The terminal may recognize the terminal's own frame (reverse cycle) by the NB (Next Batch) received from the forward radio link and the frame number value, and transmit the packet using the packet number.

Hereinafter, a time slot designation method of a reverse radio link according to the present invention will be described with reference to the flowchart of FIG. 3.

First, it is specified whether the packet to be transmitted is a connected packet or a connectionless packet (S6). That is, since the connected packet and the unconnected packet are configured with different sync signals, the receiver can read the sync signal to determine whether the currently received packet is a disconnected packet or a connected packet. It is possible to predict in advance whether the packet is a connectionless packet or a connection type packet.

As a result of the determination, in the case of the connection type packet, the total number of packets to be transmitted is calculated using the packet length, the primary packet length, and the secondary packet length to be transmitted (S7).

Then, it is determined whether (total number of packets to be transmitted + current packet position-1) is larger than the maximum specifiable number of packets (S8).

If the determination result (total number of packets to be transmitted + current packet position-1) is larger than the maximum number of packets that can be specified, the packets are sequentially designated from (maximum number of packets that can be specified-the total number of packets to be transmitted + 1) ( S9) When the determination result (total number of packets to be transmitted + current packet position-1) is equal to or smaller than the maximum specifiable number of packets (current packet position-total number of packets to be transmitted +1) is less than zero (S). It is determined whether or the same (S10).

As a result of determination, if (current packet position-total number of packets to be transmitted +1) is less than or equal to zero (0), the packets are sequentially assigned from the lowest packet, and vice versa (current packet position- {total number of packets to be transmitted). / 2} + 1) sequentially specify the packets (S11, S12).

The current packet position is obtained according to the (capcode extraction value) MOD (the maximum number of packets that can be specified) (S5).

On the other hand, in the time slot designation method of the present invention, as shown in FIG. 4B, the synchronization signal Sync is composed of a single packet linked in a form present only in the first packet.

That is, the first packet is composed of a synchronization signal (Sync), a header, a LPN (linked packet number), a first message, and a frame error correction code (FEC) as shown in FIG. 6. Consists of frame error correction code only.

Therefore, the channel efficiency can be increased.

Depending on the transmission rate, the frame error correction code (FEC) may be applied to one or more, and the LPN value represents the number of connected packets. In the case of an unconnected packet, "0" is displayed. Indicates that there is one next packet to be radiolinked.

As described above, in the present invention, when a time slot is designated in the S-ALOHA method of a connected packet, a synchronization signal exists only in the first packet when a transmission message corresponding to a plurality of packet lengths transmits a long message in one cycle. As a result, the channel efficiency was increased.

In the above, the present invention has been illustrated and described with reference to specific preferred embodiments, but the present invention is not limited to the above-described embodiments and is not limited to the spirit of the present invention. Various changes and modifications will be made possible by those who have.

Claims (7)

A method of designating a time slot for a reverse radio link using an Aloha method in a two-way radio calling communication system including at least one radio calling system and a radio calling terminal, When the transmission message uses a single unit packet, the radio call terminal unitizes the message, and when the transmission message uses a plurality of unit packets, it calculates the number of packets required to transmit the message and the Allocating as many timeslots as necessary packets into a single packet to produce a long packet; Determining a timeslot location to transmit, And transmitting to the timeslot location. The method of claim 1, wherein the capcode extraction value is determined by [(capcode setting value) AND (mask bit shift mask unit)] to determine the time slot position to be transmitted, wherein the capcode setting value is A reverse bit characterized by the mask bit indicating the mask unit and the bit number of the corresponding bit in the number of packets within a reverse unit cycle, except for a matching bit having a high collision probability with a forward frame in the address; Method of designating time slot of radio link. According to claim 1, wherein the total number of packets to be transmitted in order to make a single packet [{(packet length to be transmitted minus 1 packet length) / secondary packet length} + 1 (where {} region applies rounding) ], And Judging whether (total number of packets to be transmitted + current packet position-1) is larger than the maximum allowable number of packets to determine the position of the timeslot, If the determination result (total number of packets to be transmitted + current packet position-1) is larger than the maximum number of packets that can be specified, assigning packets sequentially from (maximum number of packets that can be assigned to the total number of packets to be transmitted +1) Wow, As a result of the determination, if (total number of packets to be transmitted + current packet position-1) is less than or equal to the maximum allowable number of packets (current packet position-total number of packets to be transmitted +1) is less than or equal to zero (0). Judging, As a result of determination, if (current packet position-total number of packets to be transmitted +1) is less than or equal to zero (0), the packets are sequentially assigned from the lowest packet, and vice versa (current packet position- {total number of packets to be transmitted). / 2} +1) timeslot designation method of the reverse radio link comprising the step of sequentially specifying the packet. 2. The method of claim 1, wherein the current packet position is determined using a capcode extraction value and a maximum assignable packet number to determine a time slot position to be transmitted, and the maximum assignable packet number is an area received through a forward radio link. A time slot designation method of a reverse radio link, characterized by being determined by a division code value (BDC). 2. The method of claim 1, wherein the radio call terminal is connected or disconnected through a sync code in the radio call system when the packet is transmitted differently depending on whether the packet to be transmitted through the reverse radio link is a connected packet or a disconnected packet. Recognizing the synchronization unit of the second unit packet of the connection type packet as a message instead of the synchronization code; Reading the field indicated in the message through the first packet within the time to complete the reception of the second packet to calculate the length of the connected packet, and if the first packet is not recognized, continuously detecting the synchronization unit until normal synchronization is detected. A time slot designation method of a reverse radio link, further comprising. A method of designating a time slot of a reverse radio link in a two-way radio call communication system including one radio call system and a plurality of radio call terminals, When the paging system designates one or more timeslots for a message to be transmitted by the terminal through a forward radio link, the paging terminal makes a long packet by single packetizing the message using packets connected in unit packets; , And transmitting the packet to a time slot position designated by the radio call system. 7. The method of claim 6, wherein the wireless caller is connected or disconnected through a sync code when the syncing part of the packet is differently set according to whether the packet to be transmitted through the reverse radio link is a connected packet or a connectionless packet. Recognizing the synchronization unit of the second unit packet of the connection type packet as a message instead of the synchronization code; Reading the field indicated in the message through the first packet within the time to complete the reception of the second packet to calculate the length of the connected packet, and if the first packet is not recognized, continuously detecting the synchronization unit until normal synchronization is detected. A time slot designation method of a reverse radio link, further comprising.