JP2000307505A - Radio system adopting low speed frequency hopping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize a spread rate of frequency channels used by a relay station, to simplify the configuration of the relay station and to build up the radio system at a comparatively low cost. SOLUTION: The system consists of base stations 1a, 1b connected to a LAN 2, pagers 8a-8c having only a reception function, and relay stations 5a, 5b that relays a ratio signal between the base stations and the pagers. The base station 1a conducts frequency hopping in a different hopping pattern from that of the other base station 1b, the relay station 5a conducts the frequency hopping with the same hopping period and the same frequency channel number as those of the base station 1b in a communication area 6 but in the different hopping pattern from that of the base station 1b and conducts radio communication through a frequency channel f2 synchronously with the base station. In the cast that the base station 1b transmits information to the pager 8a, the base station 1b transmits the information to the relay station 5a through the frequency channel f2 and the relay station 5a transmits the information to the pager 8a while taking synchronization with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low frequency hopping radio system including a base station connected to a wired network, a terminal station having at least a receiving function, and a relay station for performing radio relay between the base station and the terminal station. .

[0002]

2. Description of the Related Art Conventionally, in a low-speed frequency hopping radio system in a premises, a base station has been added to increase the number of terminal stations and expand the communication area. The communication distance of the base station is about several tens of meters, and since the base station is connected to a wired network, the installation of a network cable is necessary to add the base station. However, when a local pager for transmitting a character message of several bytes is introduced as a terminal station, adding an additional base station requires a large-scale construction, resulting in a problem in cost.

Japanese Patent Laid-Open Publication No. Hei 8-163133 discloses a radio station and a relay station that transmit and receive data in packet units, have a plurality of frequency channels, and use a low-speed frequency hopping scheme that changes the frequency channel used. A peer-to-peer digital wireless communication system is disclosed. This publication discloses a registration unit that registers a radio station and another relay station within a communicable distance with a relay station, and determines whether the communication between the radio station and another relay station registered in the registration unit is performed. And a communication unit for performing wireless data communication on the frequency channel changed by the change unit, and registering a wireless station and another relay station within a communicable distance. In addition, the frequency channel is changed depending on whether or not communication is performed with a registered wireless station and another relay station, and wireless communication is performed on the changed frequency channel.

[0004]

In this publication, a relay station for wirelessly communicating with a wireless station or another relay station is used. There is no problem, and a wireless system can be constructed relatively inexpensively even when a local pager is introduced.

[0005] However, in this publication, registration means for registering a radio station and a relay station within a communicable distance is provided, and communication is performed with the radio station and the relay station registered in the registration means. A frequency channel is changed, communication is performed on the changed frequency channel, and in the case of communication with a radio station and a relay station whose address is not registered in the registration means, a frequency channel for relay station control is changed. Due to the configuration, there is a problem that the ratio of the frequency channels used in the relay station is biased and the spreading factor of the frequency becomes uneven. Further, a registration unit for registering a wireless station and another relay station within a communicable distance with the relay station is required, so that the configuration of the relay station is complicated.

Therefore, according to the present invention, the spreading factor of the frequency channel used in the relay station can be made uniform, the configuration of the relay station can be simplified, and the introduction of a local pager is relatively inexpensive. Provide a low frequency hopping wireless system that can build a system. Also,
The third aspect of the present invention further provides a low-speed frequency hopping wireless system capable of reducing the power consumption of a terminal station.

[0007]

According to the first aspect of the present invention,
A base station connected to a wired network, a terminal station having at least a receiving function, and a relay station that performs wireless relay between the base station and the terminal station. The base station is connected to another wired network. The relay station performs frequency hopping with a hopping pattern different from that of the base station, and the relay station performs frequency hopping with a hopping pattern different from that of the base station with the same hopping cycle and the same number of frequency channels as the base station within the communication range, and at least one When radio communication is performed by synchronizing with the base station on one frequency channel and a terminal station outside the communication range of the base station performs radio communication with the base station, the communication between the base station and the communication range of the base station is performed. The radio communication is performed by synchronizing with the relay station on one frequency channel, and the synchronization is performed between the relay station and the terminal stations within the communication range of the relay station. It is to perform wireless communication Te.

According to a second aspect of the present invention, in the low frequency hopping wireless system according to the first aspect, a plurality of relay stations are arranged, each relay station having the same hopping cycle and the same number of frequency channels as other relay stations, and Performs frequency hopping with different hopping patterns, performs hopping synchronization with a relay station in an adjacent communication range on one frequency channel, and performs wireless communication, and synchronizes with each relay station on one frequency channel to perform wireless communication. Communication.

According to a third aspect of the present invention, in the low-speed frequency hopping wireless system according to the first or second aspect, a standby frequency is assigned to a terminal station in advance, and the terminal station and a base station or a relay station are assigned the standby frequency assigned to the base station or the relay station. Perform wireless communication in synchronization with the terminal station, the power supply stop control means for stopping the power supply to its own radio unit during the other frequency period until the base station or the relay station becomes the next standby frequency. It is provided.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the entire system, where 1a and 1b are LANs which are wired networks.
(Local Area Network) Base stations connected to 2, 3a, 3b
Is a wireless adapter which is a terminal station having a transmission / reception function arranged in the communication area 4 of the base station 1a, 5a is a relay station arranged in the communication area 6 of the base station 1b, and 5b is a communication of the relay station 5a. Another relay station arranged in the area 7a,
Reference numerals 8a and 8b denote pagers, which are terminal stations having only a reception function arranged in the communication area 7b of the relay station 5a, and 8c.
Is a pager which is a terminal station having only a receiving function arranged in the communication area 9 of the relay station 5b.

As shown in FIG. 2, the base stations 1a and 1b include an MPU (microprocessor) 11 constituting a control unit body, and a ROM (read only memory) storing a program for controlling the respective units by the MPU 11. 12,
A RAM (random access memory) 13 provided with a memory for storing data to be transmitted / received, a memory used when the MPU 11 executes a program, and the like;
LAN controller 14 for controlling connection to N2, wireless unit 1 having transmission / reception function of low-speed frequency hopping method
5, an antenna 16 connected to the radio unit 15 and a baseband processing unit 17 for performing bit synchronization, flag removal, and the like of data demodulated by the radio unit 15.
1, ROM 12, RAM 13, LAN controller 14
Are connected by a bus line 18.

As shown in FIG. 3, the wireless adapters 3a and 3b are connected to an MPU 21 which constitutes a control unit main body.
ROM2 in which U21 stores a program for controlling each part
2. A memory for storing data to be transmitted / received or the MPU 2
RAM 1 provided with a memory and the like used when 1 executes a program; interface 24 for controlling connection with a terminal such as a personal computer; radio unit 25 having a transmission / reception function of a low-speed frequency hopping system; The MPU 21 and the ROM include an antenna 26 connected to the MPU 21 and a baseband processing unit 27 for performing bit synchronization, flag removal, and the like of data demodulated by the radio unit 25.
22, a RAM 23, and an interface 24 are connected by a bus line 28.

As shown in FIG. 4, the relay stations 5a and 5b are provided with an MPU 31 which constitutes a control unit main body.
Is provided with a ROM 32 storing a program for controlling each unit, a memory storing data to be transmitted and received, and a memory used when the MPU 31 executes the program.
AM 33, a radio unit 34 having a transmission / reception function of a low-speed frequency hopping system, and an antenna 3 connected to the radio unit 34
5 and bit synchronization of data demodulated by the radio unit 34,
A baseband processing unit 36 that performs flag removal and the like;
The MPU 31, ROM 32 and RAM 33 are connected by a bus line 37.

As shown in FIG. 5, the pagers 8a, 8b and 8c include an MPU 41 constituting a control unit main body,
ROM in which a program for controlling each part is stored by the PU 41
42, a RAM 43 provided with a memory for storing received data and a memory used when the MPU 21 executes a program, a display unit 44 for displaying received data, a radio unit 45 having a low-speed frequency hopping receiving function, The antenna 46 connected to the radio unit 45 and the radio unit 4
5 includes a baseband processing unit 47 for performing bit synchronization, flag removal, and the like of the data demodulated in step 5.
The OM 42, the RAM 43, and the display unit 44 are a bus line 48.
Connected by

Each of the base stations 1a and 1b performs frequency hopping asynchronously according to a different hopping pattern, and performs CSMA / CA (Carrier Sense Multiple Acc).
The wireless communication is performed with the wireless adapters 3a and 3b under the control by esswith collision avoidance. Each of the relay stations 5a and 5b is independently installed independently of the LAN 2. The relay station 5a performs frequency hopping with the same hopping cycle and the same frequency channel as the base station 1b in the communication range, and with a different hopping pattern from the base station 1b, and communicates with the base station 1b using one frequency channel. The wireless communication is performed in synchronization. The relay station 5b has the same hopping cycle and the same frequency channel as the relay station 5a within the communication range,
In addition, frequency hopping is performed with a hopping pattern different from that of the relay station 5a, and wireless communication is performed in synchronization with the relay station 5a on one frequency channel.

For example, the base stations 1a and 1b, the relay station 5
FIG. 6 shows hopping patterns used by a and 5b. In the figure, f1, f2, f3, f4, f
5, f6, f7, f8, f9, f10, f11 indicate frequency channels, each of which is composed of 10 waves. That is, the base station 1a performs the operations of f1, f2, f4, f8, f5, f10, f
The frequency hopping is performed to 9, f7, f3, f6, f1,..., And the base station 1b performs f5, f9, f6, f11, f10, f8, f
The frequency hopping is performed to 4, f7, f2, f3, f5,..., And the relay station 5a performs f10, f6, f9, f4, f5, f7, f1.
The frequency hopping is performed to 1, f8, f2, f1, f10,..., And the relay station 5b performs f10, f5, f6, f8, f1, f9, f
Frequency hopping is performed in the order of 3, f2, f11, f7, f10,. Note that the frequency hopping between the base station 1a and the base station 1b does not necessarily need to be synchronized.

FIG. 7 shows the base stations 1a and 1b and the relay station 5
5A and 5B show the timing of control packets transmitted by a and 5b and the ON / OFF relationship of power supplied to the radio unit 45 of the pagers 8a, 8b and 8c. For example, in the system of FIG. 1, the relay stations 5a and 5b switch the hopping frequency every 0.4 seconds in accordance with the low-speed hopping and transmit a control packet, and the respective pagers 8a and 8b.
The MPU 41 of b, 8c has a power control means, and when the control packet is received from the relay stations 5a, 5b at the standby frequency f2, the power of the radio unit 45 is turned on for 0.4 seconds.
Then, program control is performed so that the power of the wireless unit 45 is turned off for 3.6 seconds until the frequency becomes f2.

When the pagers 8a, 8b, 8c are within the communication area of the base stations 1a, 1b, the base stations 1a, 1b switch the hopping frequency every 0.4 seconds in accordance with the low-speed frequency hopping. And the MPU 41 of each of the pagers 8a, 8b, and 8c transmits the control packet when the base station 1a,
When the control packet is received from 1b, the power of the radio unit 45 is turned on for 0.4 seconds during which this frequency stays, and after the elapse of this frequency stay time, 3.6 seconds until the next frequency becomes the standby frequency f2. Controls the program so that the power of the wireless unit 45 is turned off.

FIG. 8 shows the format of a packet. FIG. 8A shows the base stations 1a and 1b and the relay stations 5a and 5a.
b, wireless adapters 3a, 3b, pagers 8a, 8b, 8
The format of the wireless packet transmitted and received by c, (b) is
TCP / IP (Ttansmission Contr) flowing over LAN2
ol Protocol / Internet protocol) packet format, (c) shows the base stations 1a and 1b and the relay station 5a,
5b is a format of a control packet to be transmitted.

The wireless packet includes a destination address, a source address, a TCP / IP packet body, and a CRC (Cyclic Redundancy Check) for error detection.
Before and after that, the receiving side adds a flag for synchronization. The TCP / IP packet has a preamble and a CRC added before and after the body of the TCP / IP packet,
The P / IP packet body is composed of a data section in which a destination address on the LAN, a source address, a message and the like are set. The control packet includes all wireless adapters 3a,
3b, a destination address in which a global address that can be received by the relay stations 5a, 5b, and the pagers 8a, 8b, 8c is set, a source address in which an address of the base station or the relay station is set, control information, a base station or a relay. A hopping pattern section in which the hopping pattern used by the station is set, and a CRC for error detection, and before and after the hopping pattern section, a flag for synchronizing the receiving side is added.

The wireless adapter 3a listens at an arbitrary frequency, and as shown in FIGS.
When the control packet CP1 transmitted from the base station 1a is received, hopping synchronization is established with the base station 1a.
The frequency hopping is started according to the same hopping pattern as a. The wireless adapter 3a and the base station 1a perform bidirectional communication under access control by CSMA / CA. The wireless adapter 3
The same applies to b.

The base station 1a switches the frequency within 0.4 seconds according to the hopping pattern, and transmits a control packet at least once within 0.4 seconds as shown in FIG. The base station 1a transmits a TCP / IP signal to the LAN2.
Send and receive packets.

When the power is turned on, the relay station 5a
The program in the ROM 32 is activated to perform the initial setting for the wireless unit 34. Then, when the radio unit 34 is in the reception state, as shown in FIGS. 9 and 10, the base station 1b stands by at an arbitrary frequency, for example, the frequency f2, and when the frequency of the base station 1b within the communication range becomes f2, the base station 1b Control packet C from
Upon receiving P2, hopping synchronization is established with the base station 1b. Then, the relay station 5a starts frequency hopping according to a predetermined hopping pattern.

The relay station 5a has a function of receiving and relaying if the destination address of the wireless packet is addressed to the pagers 8a and 8b and the source address is the base station 2b which is in hopping synchronization. That is, as shown in FIG. 9, the relay station 5a transmits, for example, a control packet CP3 to the pager 8a, whereby the pager 8a establishes hopping synchronization with the relay station 5a.

Similarly to the relay station 5a, when the power of the relay station 5b is turned on, the program of the ROM 32 is activated and the radio unit 34 is initialized. Then, when the radio unit 34 is in the reception state, as shown in FIG. 10, the radio unit 34 waits at an arbitrary frequency, for example, the frequency f10, and the relay station 5a within the communication range.
When the frequency becomes f10, the control packet CP4 is received from the relay station 5a to establish hopping synchronization. Then, the relay station 5b starts frequency hopping according to a predetermined hopping pattern.

Further, the relay station 5b has a function of receiving and relaying if the destination address of the radio packet is addressed to the pager 8c and the source address is the relay station 5a which is in hopping synchronization. That is, the relay station 5a
Transmits a control packet CP5 to the pager 8c as shown in FIG. 10, whereby the pager 8a establishes hopping synchronization with the relay station 5a.

Each of the pagers 8a, 8b, 8c is driven by a battery and, as shown in FIG.
When the control packets from the relay stations 5a and 5b are received at the time of 2, the power of the radio unit 45 is turned on in synchronization with the hopping cycle only at that time, and the power of the radio unit 45 is turned off at other times.
Power consumption is reduced by performing an intermittent reception operation of performing FF. The power control of the radio unit 45 is performed by a control signal from the MPU 41.

In such a configuration, for example, when transmitting information from the wireless adapter 3a to the pager 8a,
Communication control is performed according to the sequence shown in FIG. First, the wireless adapter 3a transmits the wireless packet WP1 after performing the carrier sense CS to the base station 1a. On the other hand, after confirming that there is no CRC error, the base station 1a returns an ACK (ACKnowledgement). In addition,
Upon detecting the CRC error, the base station 1a transmits a retransmission request radio packet to the radio adapter 3a.

When the base station 1a normally receives the wireless packet WP1 from the wireless adapter 3a, it removes the flag, destination address, source address, and CRC added to the wireless packet WP1, and then stores the TCP / TCP in the RAM 13.
Stores the IP packet body. MPU 11 is RAM 13
When it is determined that the destination address in the TCP / IP packet body stored in the TCP / IP
After adding a preamble and a CRC to the body of the IP packet and performing carrier sense CS, the TCP / I
It is transmitted as a P packet TP.

The other base station 1b connected to the LAN 2 receives the TCP / IP packet TP from the LAN 2. When the destination address in the body of the TCP / IP packet is identified as pager 8a, the packet is added to the body of the TCP / IP packet with a flag, a destination address, a source address, and a CRC, and the wireless packet W is added.
Convert to P2. At this time, the address of the pager 8a is set as the destination address to be added, and the address of the base station 1a is set as the source address. And base station 1
The wireless unit 15 of b, the hopping pattern of its own frequency hopping, that is, f5, f9, f6, f11, f10,
After performing carrier sense CS at each frequency in the order of f8, f4, f7, f2, f3, f5,..., the wireless packet WP2 is transmitted at each frequency to the pager 8a.

Here, since the relay station 5a, which is hopping-synchronized with the base station 1b, has the same frequency as the base station 1b when the frequency is f2, the pager 8a transmitted by the base station 1b is transmitted.
It receives the wireless packet WP2 addressed to it. Wireless packet W
After confirming that there is no CRC error, the relay station 5a that has received P2 returns an ACK to the base station 1b. When the relay station 5a detects a CRC error, the base station 1
b, and transmits a retransmission request wireless packet.

When the relay station 5a normally receives the wireless packet WP2 from the base station 1b, it removes the flag, destination address, source address, and CRC added to the wireless packet WP2, and then stores the TCP / IP in the RAM 33. The packet body and the destination address are stored. When the MPU 31 identifies that the destination address stored in the RAM 33 is the pager 8a, the MPU 31 adds a flag, a destination address, a source address, and a CRC to the body of the TCP / IP packet and converts the TCP / IP packet into a wireless packet WP3.

Then, the radio section 34 of the relay station 5a uses its own frequency hopping hopping pattern,
f10, f6, f9, f4, f5, f7, f11, f8, f2, f
After performing carrier sense CS at each frequency in the order of 1, f10,..., The wireless packet W is transmitted to the pager 8a at each frequency.
Send P3.

The pager 8a existing in the communication area 7b of the relay station 5a receives the radio packet WP3 transmitted by the relay station 5a. The pager 8a stores the TCP / IP packet main body in the RAM 43 after removing the flag, the destination address, the transmission source address, and the CRC added to the wireless packet WP3 received by the baseband processing unit 47. The MPU 41 uses the TCP / I stored in the RAM 43
Data is extracted from the P packet body, and the data content is displayed on the display unit 44. Thus, information transmission from the wireless adapter 3a to the pager 8a is completed. In addition,
Since the pager is a reception-only device, it is not possible to request retransmission when an error occurs, so it is desirable to transmit the same packet a plurality of times.

Here, the pager 8a is connected to the relay station 5a.
Has been described as an example, the pager 8a exists in the communication area 6 of the base station 1b, and hopping synchronization is established with the base station 1b. Can directly receive the transmitted wireless packet WP2. In this case as well, the flag added to the wireless packet WP2, the destination address, the source address,
After removing the CRC, the main body of the TCP / IP packet is stored in the RAM 43, and then the data of the main body of the TCP / IP packet is extracted, and the data content is displayed on the display unit 44.

Next, from the wireless adapter 3a to the pager 8c
The case where information is transmitted to the server will be described. In this case, the communication control is performed according to the sequence shown in FIG. 10, the wireless packet WP2 is transmitted from the base station 1b to the relay station 5a, and is the same as the above-described example until the relay station 5a receives the wireless packet WP2. . However, in this case, the address of the pager 8c is set as the destination address of the TCP / IP packet body.

Relay station 5a receiving radio packet WP2
After confirming that there is no CRC error, ACK is returned to the base station 1b. When the relay station 5a normally receives the wireless packet WP2 from the base station 1b, the flag, the destination address,
After removing the source address and CRC, T
The CP / IP packet body and the destination address are stored.
When the MPU 31 identifies that the destination address stored in the RAM 33 is the pager 8c, a flag, a destination address, a source address,
The packet is converted into a wireless packet WP4 by adding a CRC. Then, the radio unit 34 of the relay station 5a determines the hopping pattern of its own frequency hopping, that is, f10, f6, f9,
After performing carrier sense CS at each frequency in the order of f4, f5, f7, f11, f8, f2, f1, f10,.
The wireless packet WP4 is transmitted at each frequency to c.

Here, since the other relay station 5b existing in the communication area 7a of the relay station 5a is hopping-synchronized with the relay station 5a, the same frequency as that of the relay station 5a when the frequency is the standby frequency f10. And the wireless packet WP4 addressed to the pager 8c transmitted by the relay station 5a is received. The relay station 5b that has received the wireless packet WP4 receives the CRC
After confirming that there is no error, the relay station 5a
CK is returned. When detecting the CRC error, the relay station 5b transmits a retransmission request wireless packet to the relay station 5a.

When the relay station 5b normally receives the wireless packet WP4 from the relay station 5a, it removes the flag, destination address, transmission source address, and CRC added to the wireless packet WP4, and then stores the TCP / IP in the RAM 33. The packet body and the destination address are stored. When the MPU 31 identifies that the destination address stored in the RAM 33 is the pager 8c, the MPU 31 adds a flag, a destination address, a source address, and a CRC to the body of the TCP / IP packet and converts the TCP / IP packet into a wireless packet WP5.

Then, the radio section 34 of the relay station 5b has its own frequency hopping hopping pattern,
f10, f5, f6, f8, f1, f9, f3, f2, f11, f
After performing carrier sense CS at each frequency in the order of 7, f10,..., The wireless packet W is transmitted to the pager 8c at each frequency.
Send P5.

The pager 8c existing in the communication area 9 of the relay station 5b transmits the radio packet W transmitted by the relay station 5b.
Receives P5. The pager 8c is a baseband processing unit 4.
After removing the flag, destination address, source address, and CRC added to the wireless packet WP5 received at 7, the TCP / IP packet body is stored in the RAM 43. The MPU 41 uses the TCP / IP stored in the RAM 43
Data is extracted from the packet body, and the data content is displayed on the display unit 44. Thus, information transmission from the wireless adapter 3a to the pager 8c is completed.

As described above, for the pagers 8a to 8c out of the range of the communication area of the base station 1b, the relay stations 5a, 5c
5b, the communication can be performed. Therefore, when the number of pagers is increased to expand the entire communication area, the LAN 2 is used.
It is only necessary to increase the number of relay stations that are independently arranged without increasing the number of base stations connected to the network. Therefore, there is no problem of LAN facility construction, and a system can be constructed relatively inexpensively.

Further, it is not necessary to register another relay station or pager in the communication area as a relay station in advance, so that no registration means is required and the configuration can be simplified. Further, in communication with the pager, the frequency channel is not changed depending on whether or not the relay station is registered. In the case of communication with an unregistered relay station, the frequency channel is not changed to the relay station control frequency channel. In this method, the bias of the ratio of the frequency channels used can be eliminated, and the spreading factor of the frequency can be made uniform.

Further, each of the pagers 8a, 8b, 8c
When the control packets from the relay stations 5a and 5b are received at the standby frequency f2, the power of the radio unit 45 is turned on in synchronization with the hopping cycle only at that time, and the power of the radio unit 45 is turned off otherwise. Low power consumption can be achieved.

In this embodiment, a case has been described where a pager having only a receiving function is used as a terminal station. However, the present invention is not necessarily limited to this, and a terminal station having both transmitting and receiving functions is used. Is also good. In this case, when transmitting information from the terminal station to the wireless adapter 3a, the sequence shown in FIGS. 9 and 10 may be reversed.

In this embodiment, the case where two relay stations are used has been described as an example. However, the present invention is not limited to this, and three or more relay stations may be used.
Further, in this embodiment, the base station and the relay station transmit to the pager using all hopping channels, but the present invention is not necessarily limited to this.
The frequency on which the pager is waiting may be determined in advance, and transmission to the pager may be performed using only a single frequency.

[0047]

According to the invention described in each claim, the spreading factor of the frequency channel used in the relay station can be made uniform and the configuration of the relay station can be simplified. A system can be constructed at low cost. Further, according to the third aspect of the invention, it is possible to further reduce the power consumption of the terminal station.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an entire system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a base station according to the embodiment.

FIG. 3 is an exemplary block diagram showing a configuration of a wireless adapter according to the embodiment;

FIG. 4 is a block diagram showing a configuration of a relay station according to the embodiment.

FIG. 5 is a block diagram showing a configuration of a pager according to the embodiment.

FIG. 6 is a diagram showing an example of a frequency hopping pattern of a base station and a relay station according to the embodiment.

FIG. 7 shows the transmission timing of control packets of the base station and the relay station and ON / OFF of a pager power supply in the embodiment.
The figure which shows a relationship.

FIG. 8 is a view showing a format of various packets in the embodiment.

FIG. 9 is an exemplary view showing a sequence example at the time of transmitting information from the wireless adapter to the pager in the embodiment.

FIG. 10 is a view showing another example of the sequence when information is transmitted from the wireless adapter to the pager according to the embodiment.

[Explanation of symbols]

 1a, 1b base station 2 LAN 3a, 3b wireless adapter 5a, 5b relay station 8a, 8b, 8c pager 4, 6, 7a, 7b, 9 communication area

Claims (3)

[Claims] 1. A base station connected to a wired network, a terminal station having at least a receiving function, and a relay station for performing wireless relay between the base station and the terminal station, wherein the base station is a wired network. Performs frequency hopping with a different hopping pattern from other base stations connected to the relay station, the relay station has the same hopping cycle as the base station within the communication range, the same number of frequency channels and a different hopping pattern from the base station. When performing frequency hopping and performing wireless communication in synchronization with the base station on at least one frequency channel, when the terminal station outside the communication range of the base station performs wireless communication with the base station, A wireless communication is performed between a station and a relay station within the communication range of the base station by synchronizing with one frequency channel. A low-frequency hopping wireless system, wherein wireless communication is performed with synchronization with the terminal station within a communication range. 2. A plurality of relay stations are arranged, each relay station having the same hopping cycle and the same number of frequency channels as other relay stations,
In addition, while performing frequency hopping with different hopping patterns, wireless communication is performed with hopping synchronization with a relay station in an adjacent communication range using one frequency channel, and synchronization is performed between the respective relay stations using one frequency channel. 2. The low-speed frequency hopping wireless system according to claim 1, wherein the wireless communication is performed by wireless communication. 3. A standby frequency is assigned to a terminal station in advance, and the terminal station performs radio communication with the base station or the relay station in synchronization with the assigned standby frequency, and transmits the base station or the base station to the terminal station. 3. The low-speed frequency hopping device according to claim 1, further comprising a power stop control unit that stops power supply to its own radio unit during another frequency period until the relay station becomes the next standby frequency. Wireless system.