JPH08125582A - Radio wave communication method using low-speed frequency hopping system - Google Patents

Abstract

PURPOSE: To easily establish a hopping period by permitting a slave set to normally wait by means of a poling channel and permitting a master set to execute packet communication within a usage possible time at the time of a contention channel or receiving the usage possible time. CONSTITUTION: The master set and the slave set consist of a control part 11 and a radio wave part 12. The control part 11 sets a channel in the radio wave part 12, fetches data received by the radio wave part 12 and a level and transmits transmission data to the radio wave part 12. When it is recognized that the carrier sense CS of the poling channel f1, the master set transmits the contention channel f7 and the usage possible time through the use of the channel f1 to the whole slave sets and the slave sets receive the channel f7 and the usage possible time of the channel. Then, the master set and the slave set execute packet communication within the usage possible time by the channel and the master set returns the channel to f1 when the time elapses. Then, the succeeding channel f7 and the channel usage possible time are transmitted to the whole slave sets within a radio wave zone for the succeeding packet communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-frequency frequency system in which one master unit and one or more slave units are arranged in a wireless zone, and wireless communication is performed between the master unit and the slave units by a low-frequency hopping method. The present invention relates to a wireless communication method using a hopping method.

[0002]

2. Description of the Related Art For example, in Japanese Patent Laid-Open No. 64-71344, as shown in FIG. 14 (a), a central station including a control module 1 and a plurality of parent devices 2 and 2, and each parent device 2 and 2. In a wireless system consisting of slaves 3 and 3 wirelessly connected to
As shown in (b) of FIG. 14, the occupied frequency band is divided,
A start frequency group for starting frequency allocation that is different for each child device 3 and a communication frequency group for communication that is common to a plurality of wireless devices are assigned. The start message shown in (c) is communicated, and which frequency in the communication frequency group the mobile station 3 hops from and from which frequency to hop. Then, the wireless devices to which the same hopping frequency is assigned have different start frequencies, and perform communication so that the same frequency is not output at the same time.

In FIG. 14 (b), the left frequency channel set is assigned to the start frequency group, the right frequency channel set is assigned to the communication frequency group commonly used by several radios, and the communication frequency group is It is further divided into several hopping frequency groups. The start frequencies are different among the radios to which the same hopping frequency group is assigned, and by hopping at the same timing, the same frequency does not occur at the same time, and multiple communication is possible without collision.

Further, Japanese Patent Laid-Open No. 5-191378 discloses
One packet is transmitted on one frequency, and hopping synchronization is facilitated by including in this packet a sequence of numbers indicating the order of channel numbers of the frequencies of the packets that are transmitted subsequently to this packet. is there.

[0005]

However, JP-A-64-64
According to Japanese Patent No. 71344, it is necessary to provide a set frequency for allocating a different start frequency to each slave unit and to send a start message before communication is started. Therefore, it is possible to support a large-scale system, but the control is complicated. Turn into. In addition, if there is a start-up station on the way, control becomes difficult.

Further, the one disclosed in Japanese Patent Laid-Open No. 5-191378 becomes difficult to apply when one master unit has a plurality of slave units. In addition, all the terminals for transmission are equal, and carrier sense or the like is required before transmission, and it takes time before transmission. Further, since the channel is changed for each packet and hopping is performed, the packet length is limited in order to keep the frequency occupation time within a predetermined value. Further, when an error occurs in a packet, it becomes difficult to transmit subsequent packets.

The invention according to claim 1 can easily establish synchronization, can easily enter the system even if there is a slave unit which is being started up midway, and further, even if an error occurs, the continuous data is generated. A wireless communication method using a low-speed frequency hopping method that does not affect communication.

The invention according to claim 2 can easily establish synchronization in the wireless zone, can easily enter the system even if there is a slave unit which is being started up midway, and further, an error occurs. Also, there is provided a wireless communication method using a low-speed frequency hopping method that does not affect subsequent data communication, does not cause collision of polling channels between adjacent wireless zones, and enables multiplex communication.

The invention according to claim 3 further provides a low-speed frequency hopping method capable of shortening the time until transmission by performing data transmission using a polling channel when a transmission request is made to a specific slave unit. A wireless communication method used is provided.

According to the invention of claim 4, the transmission data length can be arbitrarily set when data is transmitted to the specific slave unit by using the polling channel, and the time occupancy of the polling channel is further increased. There is provided a wireless communication method using a low-speed frequency hopping method capable of suppressing the value within a predetermined value that satisfies the standard.

The invention according to claim 5 further provides a wireless communication method using a low-speed frequency hopping method capable of reducing an error occurrence rate of packet communication using a contention channel.

[0012]

According to a first aspect of the invention, one master unit and one or more slave units are arranged in a wireless zone, and a plurality of bits of data are transmitted between the master unit and the slave units. In the wireless communication method using the low-speed frequency hopping method in which the wireless communication is performed by the low-speed frequency hopping method in which the frequency is hopping every time, in the wireless communication method, the polling channel is allocated to the wireless zone and the base unit hops based on the predetermined hopping pattern. A means for setting a contention channel consisting of channels other than the communication channel is provided, and after confirming that there is no sense in the carrier sense of the polling channel, the master unit polls all slave units in the wireless zone. The contention channel that can communicate using the communication channel and the available time of this channel are transmitted. After confirming that there is a sense in the carrier sense of the polling channel, all the slaves in the zone receive the contention channel and the available time of this channel from the master, and the master and slaves , After confirming that there is no sense by the carrier sense of the contention channel, packet communication is performed within the available time, and when the available time elapses, the channel is returned to the polling channel, and the master unit polls again. After confirming that there is no sense in the carrier sense of the channel, the polling channel is used next to all the slaves in the wireless zone to hop next and the available contention channel and the available time of this channel , And all the slaves in the wireless zone have a sense in the carrier sense of the polling channel. After confirming that, the contention channel and the available time of this channel are received from the master unit, and the master unit and the slave unit confirm that there is no sense in the carrier sense of the contention channel, and then again. The packet communication is performed within the usable time, and the master unit and the slave unit perform wireless communication while repeating the above control.

Therefore, the slave unit normally waits on the polling channel, and when it receives the contention channel and the available time of this channel from the master unit, packet communication may be performed within the available time, and hopping is easy. Synchronization can be established.

The invention according to claim 2 is composed of a plurality of wireless zones, and each wireless zone has one master unit and one or more slave units arranged, and a plurality of data sets are exchanged between the master unit and the slave units. In a wireless communication method using the low-speed frequency hopping method in which wireless communication is performed by a low-speed frequency hopping method in which a frequency is hopping for each bit, each wireless zone is assigned a polling channel of a different channel at least between adjacent wireless zones, and A unit for setting a contention channel consisting of channels other than polling channels assigned to the wireless zone to which it belongs and adjacent wireless zones, which hops to the base unit of the wireless zone based on a predetermined hopping pattern, is provided. The base unit of the zone has no sense with the carrier sense of the assigned polling channel. After confirming that, the contention channel that can communicate using the polling channel and the available time of this channel are transmitted to all the slaves in the wireless zone, and all the slaves in the wireless zone are sent. After confirming that there is a sense in the carrier sense of the assigned polling channel, the device receives the contention channel and the available time of this channel from the parent device in the same wireless zone, After confirming that there is no sense in the carrier sense of the contention channel, the master unit and the slave unit perform packet communication within the available time, and when the available time elapses, the channel becomes the assigned polling channel. Return, the base unit of each wireless zone confirms that there is no sense in the carrier sense of the polling channel that is reassigned. After confirming, send to all the slaves in the wireless zone the contention channel that can be hopped next using the polling channel and the available time of this channel, After confirming that there is a sense in the carrier sense of the assigned polling channel, the slave unit receives the contention channel and the available time of this channel from the master unit in the same wireless zone, and After confirming that there is no sense by the carrier sense of the contention channel, the master unit and the slave unit in the zone perform packet communication again within the usable time,
The master unit and the slave unit in each wireless zone perform wireless communication while repeating the above control.

Therefore, it is possible to avoid the channel collision between the adjacent radio zones, and it becomes possible to carry out the multiplex communication.

The invention corresponding to claim 3 is the wireless communication method using the low frequency frequency hopping method according to claim 1 or 2, wherein the master unit further uses a polling channel for communication. And when the available time of this channel is transmitted, when there is a data transmission request to a specific slave unit, the slave unit identification number and data specifying the specific slave unit are transmitted following the channel available time. Especially.

Therefore, data transmission from the master unit to the slave unit can be performed using the polling channel, and the time until transmission can be shortened.

The invention corresponding to claim 4 is the wireless communication method using the low-speed frequency hopping method according to claim 3, wherein the master unit uses the polling channel to determine the available time of the contention channel. When the polling channel usage time exceeds the predetermined time when the slave unit identification number and data that specify a specific slave unit are subsequently transmitted, communication is performed using the polling channel next time. The purpose is to extend the time interval until the available contention channel and the available time of this channel are transmitted, and adjust the time usage rate of the polling channel within a predetermined value.

Therefore, the packet length can be arbitrarily set when data is transmitted from the master unit to the slave unit, and the standard of the radio station of the low power data communication system is always satisfied.

The invention according to claim 5 is the wireless communication method using the low-frequency hopping method according to claim 1 or 2, wherein the master unit further counts the number of packet errors for each contention channel. Alternatively, a means for calculating the packet error rate is provided, and when the number of packet errors or the packet error rate exceeds a predetermined value, the corresponding contention channel is not set as a communicable contention channel.

Therefore, even if a packet error occurs, subsequent communication can be easily continued and the error occurrence rate can be reduced.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) This embodiment is an embodiment corresponding to claim 1, and is applied to a local wireless system in which one master unit and one or more slave units are arranged in a wireless zone. is there.

As shown in FIG. 1, the master unit and the slave unit include a control unit 11 and a radio unit 12, and an antenna 13 is connected to the radio unit 12.

The control unit 11 sets a channel for the wireless unit 12, fetches the reception data and the reception level received by the wireless unit 12, and sends the transmission data to the wireless unit 12.

As shown in FIG. 2, the control section 11 includes a contention channel setting means 11a for setting a channel for the wireless section 12 and the channel setting means 1.
There is provided a contention channel collecting portion 11b in which a plurality of contention channels set by 1a are stored. The master unit is a contention channel collecting unit 11b.
Select an appropriate channel from among and set the hopping pattern of the contention channel. The hopping pattern is composed of at least 10 or more different channels.

For example, when the polling channel f1 is assigned to the wireless zone and the channels selected from the contention channel grouping unit 11b are the contention channels f7, f8, ..., The master unit performs the wireless communication control shown in FIG. To do.

That is, the master unit first carries out carrier sensing of the polling channel f1 in S1, and if there is no sense, it can communicate in S2 with the contention channel f7.
And the available time of this channel is transmitted to all the slaves in the wireless zone by the polling channel f1. Then, at S3, the contention channel f7 is set.

In this state, the carrier sense of the contention channel f7 is performed in S5 while determining the elapse of the usable time in S4. If there is a carrier sense of the contention channel f7, the slave unit sends the message in S6. Receive the packet data of.

When the passage of the usable time is detected in S4, the channel is returned from the contention channel f7 to the polling channel f1 in S7, and the carrier sensing of the polling channel f1 is performed again in S8.

If there is no carrier sense of the polling channel f1, the contention channel f8 that can be communicated by switching the contention channel from f7 to f8 based on the hopping pattern and the usable time of this channel within the wireless zone. It is transmitted to all the slave units by the polling channel f1. Then, the contention channel f8 is set.

In this way, the master unit performs carrier sensing of the polling channel f1 every time the contention channel usable time elapses, and sequentially switches the contention channels based on the hopping pattern to switch packets with each slave unit. Communicate.

In response to the communication control of the master unit, each slave unit within the wireless zone performs the wireless communication control shown in FIG. Each slave unit always waits on the polling channel f1 assigned to the wireless zone.

Each slave performs carrier sensing of the polling channel f1 in S11, and if there is a sense, receives the contention channel f7 and the available time of this channel from the master in S12. , S13 sets the contention channel f7.

In this state, it is determined in S14 whether or not the usable time has elapsed, and in S15, it is determined whether another slave unit is using the contention channel f7. And no other handset is using the contention channel f7,
That is, after detecting that there is no carrier sense of the contention channel f7, the packet data is transmitted to the master unit in S16.

When the passage of the usable time is detected in S14, the channel is returned from the contention channel f7 to the polling channel f1 in S17, and the carrier sensing of the polling channel f1 is performed again in S18.

Then, if there is carrier sense for the polling channel f1, the next contention channel f8 and the available time of this channel are received from the master unit.

In this way, each slave unit receives the contention channel and the available time from the master unit while carrying out carrier sensing of the polling channel f1 every time the available time of the contention channel has elapsed, and the master unit receives the contention channel and the available time. And packet communication with.

In the embodiment having such a structure, as shown in FIG.
As shown in, the master unit performs carrier sense CS on the polling channel f1 and if no other wireless station uses the polling channel f1, there is no sense. Therefore, each slave unit uses the polling channel f1. The contention channel f7 that can be used for communication with each other and the available time of this channel are transmitted.

As a result, the master unit and each slave unit set the contention channel f7. After the guard time for channel switching elapses, the master unit and each slave unit enter the contention channel f7 enable state.

For example, when three slave units A, B, and C are arranged and the slave unit A first makes a transmission request to the master unit, the slave unit A determines the carrier sense C of the contention channel f7.
After performing S, it is confirmed that no other slave unit is using the contention channel f7, and then upstream packet communication is performed with the master unit.

If, for example, the slaves B and C perform carrier sense CS on the contention channel f7 for data transmission during this communication, carrier sense is present at this time and communication cannot be performed.

When the packet communication from the slave unit A to the master unit is completed, the master unit returns ACK to the slave unit A. After that, when the child device B again performs the carrier sense CS of the contention channel f7, the child device B does not use the contention channel f7 this time, and thus the child device B receives the content from the parent device. Performs upstream packet communication.

If the handset C may again perform the carrier sense CS of the contention channel f7 during this communication, the carrier sense is also present at this time and the communication cannot be performed.

When the packet communication from the slave unit B to the master unit is completed, the master unit returns ACK to the slave unit B. After that, when the child device C again carries out the carrier sense CS of the contention channel f7 again, the child device C does not use the contention channel f7 this time, so the child device C does not communicate with the parent device. For upstream packet communication.

When the packet communication from the child device C to the parent device is completed, the parent device returns ACK to the child device C. After that, when the parent device makes a transmission request to the child device B, the parent device performs carrier sense CS on the contention channel f7, confirms that there is no carrier sense, and confirms that there is no downlink packet to the child device B. Communicate. And from base unit to handset B
When the packet communication to A is completed, the handset B sends A to the base unit.
Return CK.

When such packet communication is performed and the available time elapses thereafter, the master unit performs carrier sense CS on the polling channel f1 again, and senses if another wireless station is not using the polling channel f1. Accordingly, the polling channel f1 is used to transmit the communicable contention channel f8 and the available time of this channel to each slave. That is, the communicable contention channel is switched from f7 to f8 based on the hopping pattern.

Without involving such complicated control,
If each slave unit simply waits on the polling channel f1, it can easily synchronize with the master unit. Moreover, even if the slave unit starts up on the way, if it is waiting on the polling channel f1, it can easily be synchronized with the master unit. That is, it is possible to easily enter the wireless system.

(Second Embodiment) This embodiment has the following features:
This is an embodiment corresponding to claim 3 and claim 4 and is applied to a local wireless system in the case where there are a plurality of wireless zones in which one master and one or more slaves are arranged.

A plurality of wireless zones Z1 to Z13 are arranged as shown in FIG. In addition, each wireless zone Z1 to Z1
The configurations of the master unit and the slave units arranged in No. 3 are the same as those in FIGS. 1 and 2.

FIG. 7 shows a hopping channel, which has, for example, 26 hopping channels CH1 to CH26, and frequencies f1 to f26 are set respectively.

Different polling channels CIF are allocated to each of the wireless zones Z1 to Z13 at least between adjacent wireless zones.

For example, the wireless zone Z5 is the wireless zone Z1,
Surrounded by Z2, Z6, Z9, Z8 and Z4, the master unit of the wireless zone Z5 is the polling channel f5 of the wireless zone Z5 and the adjacent wireless zones Z1, Z2, Z6 and Z.
9, Z8, Z4 polling channels f1, f2, f
The remaining 19 channels except 6, f9, f8, and f4 are set in the contention channel grouping unit 11b as a contention channel grouping, and an appropriate channel is selected from the contention channel grouping unit 11b. Set the hopping pattern for the channel.

Further, for example, the wireless zone Z10 is surrounded by the wireless zones Z6, Z7, Z11, Z13, Z12 and Z9, and the parent device of the wireless zone Z10 is the wireless zone Z10.
Polling channel f10 and adjacent wireless zone Z
6, the remaining 19 channels except the polling channels f6, f7, f11, f13, f12 and f9 of Z7, Z11, Z13, Z12 and Z9 are set in the contention channel grouping unit 11b as the contention channel group. An appropriate channel is selected from the contention channel collecting unit 11b to set the hopping pattern of the contention channel.

As described above, the polling channels are made different between the adjacent wireless zones, and the remaining 19 channels excluding the polling channel from the 26 hopping channels are allocated to the contention channels. There is no channel collision between the wireless zones, and stable multiplex communication is possible.

In this system, as shown in FIG. 8, the master unit of each wireless zone, for example, the master unit of the wireless zone Z5, performs carrier sense CS on the polling channel f5, and another wireless station uses the polling channel f5. If you are not using it, there is no sense, so you can use the polling channel f5 to communicate with each slave unit.
Send 14 and the uptime of this channel. At this time, a flag P designating whether or not there is transmission data from the master unit to the specific slave unit is added. For example, if there is no transmission data, the flag P is set to "0", and if there is transmission data, the flag P is set to "1". Since there is no transmission data this time, the flag P is set to "0" and transmitted.

After that, the master unit and each slave unit set the contention channel f14, and after the guard time for channel switching has passed, the master unit and each slave unit are in the enable state of the contention channel f14.

Thus, the contention channel f14
By using, the packet communication is possible between the master and each slave.

When the usable time of the contention channel f14 elapses, the master unit in the wireless zone Z5 performs carrier sense CS of the polling channel f5 again, and another wireless station is using the polling channel f5. If not, there is no sense, so polling channel f
5, the next communicable contention channel f15 based on the hopping pattern and the available time of this channel are transmitted to each slave unit. At this time as well, since there is no transmission data from the master unit to the specific slave unit, the flag P is set to "0" and transmitted.

After that, the master unit and each slave unit set the contention channel f15, and after the guard time for channel switching elapses, the master unit and each slave unit become the enable state of the contention channel f15.

Thus, the contention channel f15
By using, the packet communication is possible between the master and each slave.

When the usable time of the contention channel f15 elapses, the master unit in the wireless zone Z5 again performs carrier sense CS on the polling channel f5 and another wireless station uses the polling channel f5. If not, there is no sense, so the polling channel f5 is used to transmit the next communicable contention channel f16 based on the hopping pattern and the available time of this channel to each slave. At this time, if there is transmission data from the master unit to the specific slave unit, "1" is set in the flag P, and the slave unit address which is the identification number of the specific slave unit and the transmission data are added and transmitted.

As a result, the specific slave unit detects the address and receives the data from the master unit.

After that, the master unit and each slave unit set the contention channel f16, and after the guard time for channel switching has passed, the master unit and each slave unit are in the enable state of the contention channel f16.

Thus, the contention channel f16
By using, the packet communication is possible between the master and each slave.

As described above, when the master device transmits data to a specific slave device, data can be easily transmitted using the polling channel, so that the time required for data transmission can be shortened.

Further, since the slave unit can determine whether or not there is the transmission data from the master unit by the flag P of the data received on the polling channel, the slave unit can easily perform the data receiving process.

By the way, when there is no data to be transmitted to a specific slave unit, the time required for transmitting data of the contention channel and the available time of this channel on the polling channel f5, that is, the use time of the polling channel f5 is Let t0 be the available time of the contention channel, and let t1 be 91 × t0 before the available time of the contention channel elapses after the carrier sense CS of the master unit. The usage rate is about 1%.

Further, when there is transmission data for a specific slave, if the usable time of the contention channel is constant, the time usage rate of the polling channel f5 increases.

Therefore, the parent device calculates the time usage rate of the polling channel f5 from the number of transmission data in advance, and when it exceeds the predetermined value, the polling channel f5 is next used.
Is used to extend the time until the contention channel and the available time of this channel are transmitted and adjusted to satisfy a predetermined usage rate. For example, if the predetermined usage rate is within 10%, the usage time t2 (= t0 + t01) of the polling channel f5 is within 10% of (91 * t0 + t01), that is, if t01 <9 * t0, it is normal. It is not necessary to extend the time other than the guard time of t01> 9
In the case of × t0, the time interval from the use of the polling channel f5 to the next use of the polling channel f5 is extended to 10 × t2.

For example, when t01 becomes 19t0, assuming that the time is not extended, t2 = 20t0 and the time interval is 91.
At t0 + 19t0, it becomes 110t0, and the usage rate is 20t0.
It becomes about 18% at / 110t0, which means that the predetermined usage rate cannot be satisfied. Therefore, in this case, the usage rate can be 10% by setting the time interval to 10 × t2, that is, 200t0.

In this way, the master unit can arbitrarily set the data length when transmitting data to a specific slave unit, and can adjust the usage rate of the polling channel within a predetermined value. It is possible to satisfy the standard of the wireless station of the communication system.

(Third Embodiment) This embodiment is an embodiment corresponding to Claims 2 and 5, and has a plurality of wireless zones in which one master unit and one or more slave units are arranged. It is applied to a local wireless system.

As shown in FIG. 9, a plurality of wireless zones Z
1, Z2, Z3, ..
2, Z3, ... One base unit 211, 212, 213, ...
And n slave units 221, 212, ... 2
2n, 231, 232, ... 23n, 241, 242, ...
24n, ... Are arranged.

.. of each of the wireless zones Z1, Z2, Z3 ,. A plurality of host computers 261, 262, ... Are also connected to the wired cable 25.

The respective master units 211, 212, 213, ... Are the respective slave units 221, 22 in the wireless zones Z1, Z2, Z3 ,.
2, ... 22n, 231, 232, ... 23n, 241, 2
, 24n, and wireless communication using a low-speed frequency hopping method to transmit and receive data, and the host computers 261, 262, ... And the wired cable 25.
Data is transmitted and received via the.

Different polling channels are allocated between the adjacent wireless zones in each of the wireless zones Z1, Z2, Z3, ....

Independent addresses are assigned to each of the parent device, each child device, and each host computer. The communication frequency changes between the parent device and the child device in the wireless zone each time a predetermined time elapses. Therefore, if attention is paid to a certain specific frequency, it is used only at a predetermined time interval. A radio station of a low power data communication system has an average power of 10 m with respect to the frequency with the highest usage rate among the frequencies used.
There is a regulation of W or less. Therefore, the code length of the hopping frequency to be used is determined, and when the transmission output is constant regardless of each frequency, the use time rate of each frequency is limited.

The base unit and the handset units in the wireless zone have a certain frequency,
That is, packet communication is performed while staying in the contention channel. The packet communication format is
As shown in FIG. 10, a synchronization signal for the receiving side to prepare for reception such as clock reproduction, a start code indicating the beginning of data, a source address, a destination address, data, an end code indicating the end of a packet, and transmission. It consists of a CRC for detecting an error from the original address to the end code.

For example, when the child device 222 in the wireless zone Z1 sends data to the host computer 262, the child device 222 sets its own address as the source address and the address of the host computer 262 as the destination address, Wirelessly to the machine 211.

The base unit 211 receives the carrier sense, establishes the bit synchronization, identifies the start code, identifies the end code, and performs the receiving operation. When it confirms that there is no error by CRC, the source address is the slave unit 222. Identify and cordless handset 2
AC to inform 22 that it was received correctly
K is wirelessly transmitted to the child device 222.

As shown in FIG. 11, the ACK format includes a synchronization signal for the receiving side to prepare for reception such as clock reproduction, a start code indicating the beginning of data, a source address, a destination address, an ACK signal, It consists of an end code indicating the end of the signal and a CRC for detecting an error from the source address to the end code.

When the parent device 211 sends an ACK to the child device 222, the source address is its own address,
The address of the child device 222 is set as the destination address and transmitted. If the sender address could be received from the child device 222 but an error was detected by the CRC, the child device 222
To NAK. Note that carrier sense is not performed when transmitting ACK and NAK.

When the transmission source address itself cannot be correctly received from the child device 222, nothing is transmitted. The child device 222 retransmits when it receives the NAK from the parent device 211 or when there is no response within a predetermined time.

When the parent device 211 correctly receives the packet communication from the child device 222 and sends back an ACK to the child device 222, the parent device 211 receives the host computer 262.
To the CRC via the wired cable 25.

In this way, communication between arbitrary terminals becomes possible. The start code and the end code are “7E” in hexadecimal 8 bits, the CRC generator polynomial is X ¹⁶ + X ¹² + X ⁵ +1 defined by CCITT, and ACK is “A” “C”.
The ASCII code corresponding to "K" and NAK are also ASCII codes.

Each of the parent device and each child device has the same configuration as that of FIG. 1, and in particular, the control unit 11 of each parent device sets a channel for the wireless unit 12 as shown in FIG. In addition to the contention channel setting unit 11a and the contention channel collecting unit 11b that stores a plurality of contention channels set by the channel setting unit 11a, the total number of communication packets, the number of error packets, and the error for each contention channel. A packet error holding means 11c for holding each data of the packet error rate obtained by the calculation of the number of packets / the total number of communication packets is provided.

For example, assuming that the polling channel f1 is assigned to the wireless zone Z1 and the channels selected from the contention channel collecting section 11b are the contention channels f7, f8, ..., The parent device 211 of the wireless zone Z1 is shown in FIG. The wireless communication control shown in is performed.

That is, the base unit 211 first sets the polling channel f1 in the wireless unit 12 in S21, and then,
In S22, carrier sense of the polling channel f1 is performed, and if there is no sense, the communicable contention channel f7 and available time of this channel are sent to all the slave units 221 to 22n in the wireless zone Z1. And transmits on the polling channel f1. Then, in S24, the contention channel f7 is set in the radio unit 12.

In this state, the carrier sense of the contention channel f7 is performed in S26 while determining the elapse of the usable time in S25, and if there is a carrier sense of the contention channel f7, the slave unit 221 is executed in S27. ~ 22n
Packet data from any of the above.

Then, in S28, the number of received packets on the channel f7 is incremented by one. That is, the counter that counts the number of received packets is incremented. Then, S29
Check the CRC error of the packet data received in. Here, if there is a CRC error, the number of error packets of channel f7 is incremented by 1 in S30. That is, the counter that counts the number of error packets of channel f7 is incremented.

The above control is repeated until the available time elapses, and when the passage of the available time is detected in S25, the packet error rate ER7 in the channel f7 is calculated in S31. That is, ER7 = (channel f
The number of error packets of 7) / (the number of received packets of channel f7) is calculated, and the result is stored in the memory in the control unit 11.

Subsequently, in S32, the packet error rate ER7
Is larger than a predetermined value set in advance.
The predetermined value is 0.25 if the allowable error rate is 25%, for example.

If the packet error rate ER7 is larger than the predetermined value, then it is determined at S33 whether the packet error rate ER7 is the maximum including the packet error rates ERx of other contention channels. And
If the packet error rate ER7 is the maximum, the channel f7 in the contention channel set in the contention channel set unit 11b is disabled and other channels are enabled in S34. The disable state of the channel f7 continues until the packet error rate ERx of the contention channel of another frequency becomes larger than the packet error rate ER7, and during this time, the use of the channel f7 as a contention channel is prohibited.

If the packet error rate ER7 is less than or equal to a predetermined value, or if it exceeds the predetermined value and is not the maximum including the packet error rates ERx of other channels,
Channel f7 is not disabled.

Although the packet error rate ER having the maximum value is disabled here, if the number of channels to be used is large, for example, the packet error rate ER having the largest packet error rate ER may be disabled.

Subsequently, in S35, the channel is changed to the channel f.
7 is returned to the polling channel f1, that is, the polling channel f1 is set in the wireless unit 12, and S36
Then, carrier sensing of the polling channel f1 is performed again.

If there is no carrier sense for the polling channel f1, the next contention channel is selected from the contention channel set in the enabled state of the contention channel grouping unit 11b based on the hopping pattern in S37. Then, the selected contention channel and the usable time of this channel are transmitted to all the slave units 221 to 22n in the wireless zone Z1 by the polling channel f1.

Thus, the base unit 211 in the wireless zone Z1
Each time the available time of the contention channel elapses, carrier sensing of the polling channel f1 is performed, and the contention channels are sequentially switched based on the hopping pattern to perform packet communication with the slave units 221 to 22n.

The communication control of the base unit 211 in the wireless zone Z1 has been described above, but other wireless zones Z2, Z3, ...
The same applies to the parent devices 212, 213 ,.

The counters for counting the number of received packets and the number of error packets will overflow when they are constantly incremented. However, for example, if the number of received packets exceeds a certain number, both counters will overflow. Overflow can be avoided by taking measures such as shifting the digits to the right. Furthermore, the number of received packets, the number of error packets, and the packet error rate ER may be cleared after a certain period of time in consideration of changes in the communication environment.

By performing such communication control, a channel in a poor communication state is not used as a contention channel, and therefore the error occurrence rate of packet communication using the contention channel can be reduced and stable. Communication can be secured.

In this embodiment, the same effect as that of the above embodiment can be obtained. That is, it is possible to easily establish synchronization within each of the wireless zones Z1, Z2, Z3, ... And to easily enter the system even if there is a slave unit that is being started up on the way. Further, even if an error occurs, it is possible to wait for the polling channel again to perform transmission, so that it does not affect subsequent data communication.
Furthermore, collision of polling channels does not occur between adjacent wireless zones, and multiplex communication becomes possible.

[0104]

According to the invention according to claim 1, synchronization can be easily established, and even if there is a slave unit which is being started up midway, it can easily enter the system, and an error occurs. Also, communication can be continued without affecting subsequent data communication.

According to the invention according to claim 2, synchronization can be easily established in the wireless zone, and even if there is a slave unit which is being started up midway, it is possible to easily enter the system and an error occurs. Even if it does not affect the subsequent data communication, the communication can be continued, and the collision of the polling channels does not occur between the adjacent wireless zones, so that the multiple communication can be performed.

According to the invention corresponding to claim 3, when a transmission request is made to a specific slave unit, data transmission is performed using the polling channel, whereby the time until transmission can be shortened.

According to the invention according to claim 4, further, when data is transmitted to a specific slave unit by using the polling channel, the transmission data length can be arbitrarily set, and the time of the polling channel can be set. The occupation rate can be suppressed within a predetermined value that satisfies the standard.

According to the invention of claim 5, the error occurrence rate of packet communication using the contention channel can be further reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a master unit and a slave unit according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a main configuration of a control unit of the master unit according to the embodiment.

FIG. 3 is a flowchart showing communication control of the master unit according to the embodiment.

FIG. 4 is a flowchart showing communication control of the child device of the embodiment.

FIG. 5 is a diagram showing a communication timing between a master unit and a slave unit according to the embodiment.

FIG. 6 is a diagram showing a configuration of a wireless zone according to a second embodiment of the present invention.

FIG. 7 is a diagram showing an example of hopping channels used in the same embodiment.

FIG. 8 is a diagram showing communication timing between the master unit and the slave unit according to the embodiment.

FIG. 9 is a block diagram showing the configuration of a system according to a third embodiment of the present invention.

FIG. 10 is a diagram showing a configuration example of packet data of the same embodiment.

FIG. 11 is a diagram showing a configuration example of ACK data according to the same embodiment.

FIG. 12 is a diagram showing a main configuration of a control unit of the parent device of the embodiment.

FIG. 13 is a flowchart showing communication control of the master unit according to the embodiment.

FIG. 14 is a diagram for explaining a conventional example.

[Explanation of symbols]

 11 ... Control unit 11a ... Contention channel setting means 11b ... Contention channel collecting unit 12 ... Radio unit

Claims (5)

[Claims] 1. A wireless communication is performed by a low-frequency hopping method in which one master unit and one or more slave units are arranged in a wireless zone, and a frequency is hopped between the master unit and the slave unit for each multiple bits of data. In a wireless communication method using a low-speed frequency hopping method, a polling channel is assigned to a wireless zone, and hopping is performed on the master unit based on a predetermined hopping pattern, and a contention channel other than the polling channel is set. The master unit, after confirming that there is no sense in the carrier sense of the polling channel, the master unit can communicate with all the slave units in the wireless zone by using the polling channel. It sends the tension channel and the available time of this channel, and all the handsets in the wireless zone After confirming that there is a sense in the carrier sense of the polling channel,
Receiving the contention channel and the available time of this channel from the parent device, the parent device and the child device, within the available time after confirming that there is no sense in the carrier sense of the contention channel. Performs packet communication, and returns the channel to the polling channel when the available time elapses, and the parent device again confirms that there is no sense by the carrier sense of the polling channel, and then all the children in the wireless zone. To the mobile device, the next available contention channel that hops using the polling channel and the available time of this channel are transmitted, and all the slaves in the wireless zone transmit the carrier of the polling channel. After confirming that there is a sense with sense,
After receiving the contention channel and the available time of this channel from the master unit, the master unit and the slave unit confirm that there is no sense in the carrier sense of the contention channel, and then again within the available time. Wireless communication method using the low-speed frequency hopping method, characterized in that the base unit and the slave unit perform wireless communication while repeating the above-described control. 2. A plurality of wireless zones, wherein each wireless zone has one master unit and one or more slave units arranged, and frequency hopping is performed between the master unit and the slave units for each multiple bits of data. In the wireless communication method using the low-speed frequency hopping method, which performs wireless communication by the low-speed frequency hopping method, a polling channel of a different channel is allocated to at least adjacent wireless zones to each wireless zone, and the wireless base station of each wireless zone is set A means for setting a contention channel consisting of a channel excluding a polling channel assigned to a wireless zone to which the wireless zone belongs to and an adjacent wireless zone, which hops based on a predetermined hopping pattern, After confirming that there is no sense in the carrier sense of the assigned polling channel, It transmits the contention channel that can communicate using its polling channel and the available time of this channel to all the cordless handsets in the line zone, and all cordless handsets in the wireless zone are assigned. After confirming that there is a sense in the carrier sense of the polling channel, the contention channel and the available time of this channel are received from the master unit in the same wireless zone, and the master unit and slave units in the same wireless zone are received. Confirms that there is no sense with carrier sense of the contention channel, then performs packet communication within the available time, and when the available time elapses, returns the channel to the assigned polling channel, After confirming that there is no sense in the carrier sense of the polling channel that has been reassigned, the master unit does not All slaves in the wireless zone transmit the contention channel that can be hopped next using the polling channel and the available time of this channel to all slaves in the wireless zone. After confirming that there is a sense in the carrier sense of the assigned polling channel, the contention channel and the available time of this channel are received from the master unit in the same wireless zone, and the master unit in the same wireless zone is received. After confirming that there is no sense by the carrier sense of the contention channel, the slave unit performs packet communication again within the usable time, and while repeating the above control, the master unit and the slave unit in each wireless zone A wireless communication method using a low-speed frequency hopping method, characterized by performing wireless communication. 3. The master unit transmits the contention channel that can communicate using the polling channel and the available time of this channel, and when there is a data transmission request to a specific slave unit, the channel 3. The wireless communication method using the low-speed frequency hopping method according to claim 1, wherein a slave unit identification number designating a specific slave unit and data are transmitted subsequent to the available time of. 4. The master unit uses the polling channel to send a slave unit identification number designating a specific slave unit and data after the available time of the contention channel using the polling channel. If the usage time exceeds a predetermined time, polling channel is extended by extending the time interval until the contention channel that can be used for communication next and the available time of this channel are transmitted. The wireless communication method using the low-speed frequency hopping method according to claim 3, wherein the time utilization rate of the channel is adjusted within a predetermined value. 5. The base unit is provided with means for counting the number of packet errors for each contention channel or means for calculating a packet error rate, and when the number of packet errors or the packet error rate exceeds a predetermined value. 3. The corresponding contention channel is not set as a communicable contention channel.
A wireless communication method using the described low-speed frequency hopping method.