JPH1155729A - Radio communication system, radio communication method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect a plurality of radio channels simultaneously by one radio terminal and to properly attain service even when intercarrier interference takes place resulting in causing it that a radio communication channel cannot be reserved. SOLUTION: Communication is made through a plurality of radio channels by using a plurality of communication slots resulting from time-division of each of a plurality of carriers assigned to a radio channel between a radio base station 102 and a radio terminal 101. In the case that a communication slot is not available through interference of a radio communication channel, a method of selecting a desired channel in response to a communication state among a plurality of channel changeover methods and the communication slot of the radio channel is selected according to the selected channel changeover method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of allocating a plurality of carriers.
Wireless communication system in which the channel of the system is intended,
More particularly, the present invention relates to a method for using a plurality of channels in one terminal.

[0002]

2. Description of the Related Art Conventionally, personal handy phones
A plurality of carriers such as a system (hereinafter, referred to as “PHS”) and a PDC are allocated, and T.
In a wireless communication system in which a channel of the DMA-TDD scheme is used, there is no scheme in which one terminal uses a plurality of channels.

[0003]

Therefore, the above-mentioned prior art has the following problems.

[0004] In recent years, in non-voice communication that is rapidly spreading, communication speed in a single slot has become insufficient, and it has been proposed to perform wireless communication using a plurality of slots. ing. However, if a plurality of slots are used for data communication, interference between carriers is likely to occur, and the reliability of wireless communication may be reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. One wireless terminal can simultaneously connect a plurality of wireless channels, and interference between carriers occurs to secure a wireless communication line. It is an object of the present invention to provide a wireless communication system, a wireless communication method, and a wireless communication system capable of appropriately performing a service even when the service cannot be performed.

[0006]

To achieve the above object, the present invention comprises a radio base station connected to a digital line and a radio terminal communicating with the radio base station via a plurality of radio channels. Communication means for performing communication by a plurality of wireless channels using a plurality of communication slots obtained by time-dividing each of a plurality of carriers allocated to a wireless line, and communication by the communication means. And a switching unit for switching the wireless channel according to a communication condition.

In order to achieve the above object, the present invention provides a radio communication system comprising a radio base station connected to a digital line and a radio terminal communicating with the radio base station via a plurality of radio channels. A wireless communication method for a system, comprising: a communication step of performing communication through a plurality of wireless channels using a plurality of communication slots obtained by time-dividing each of a plurality of carriers allocated to a wireless line; And a switching step of switching the wireless channel according to a communication state.

Further, in order to achieve the above object, the present invention relates to a radio communication apparatus for communicating with a radio base station connected to a digital line through a plurality of radio channels, comprising: Communication means for performing communication by a plurality of wireless channels using a plurality of communication slots obtained by time-dividing each of the carriers; and switching means for switching the wireless channel according to a communication state during communication by the communication means. It is characterized by the following.

[0009]

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

In this embodiment, a switching operation of a communication channel when performing wireless data communication using a plurality of communication slots in a wireless communication system using a personal handyphone system (PHS) as a wireless communication medium will be described. .

FIG. 1 is a diagram showing a configuration of a wireless communication system according to the present embodiment. In the figure, 101 is a wireless communication terminal (PS), 102 is a wireless base station (CS), 1
03 is an ISDN network accommodating radio base stations, and 10
4 is a data communication device (P
C).

In this embodiment, two communication paths (two slots of the same carrier, 32 × 2 = 64 Kbps: R 2 + T 2) are used on the air in order to effectively use the 64 Kbps communication path of 1 Bch of the ISDN network 103. , R4 + T
The wireless connection is made using 4).

FIG. 2 is a diagram showing a use state of a communication slot of the PHS data communication system in the present embodiment. FIG. 3 is a diagram showing mapping of a physical slot on a carrier in the PHS.

In the wireless communication system having the above configuration, a switching operation of a wireless channel when performing wireless data communication using a plurality of communication slots will be described. still,
This switching operation is performed by wireless communication between the wireless communication terminal 101 and the wireless base station 102 shown in FIG. 1, and the switching is performed by any of three wireless channel switching methods described later. Is determined in advance.

FIG. 4 is a diagram for explaining a radio channel switching operation according to the present embodiment. In the figure, f1
Is a switching source carrier and f2 is a switching destination carrier. Here, when communication is performed using two communication slots on the switching source carrier f1 (401), if a failure occurs in one communication slot and an error continues more than a specified number of times (402), one of the two communication slots will fail. It confirms the vacancy of the switching destination carrier f2 including the slot in which communication is continued, and performs carrier switching (403). Then, the communication using the two communication slots on the switching destination carrier f2 is restarted (40).
4).

FIG. 5 is a diagram for explaining the radio slot switching operation according to the present embodiment. In this example, when a failure occurs in one communication slot, the communication is switched to another empty slot in the same carrier and communication is resumed.

That is, when communication is performed using two communication slots on the carrier f1 (501), 1
If a failure occurs in one of the communication slots and the error continues for a specified number of times (502), the communication slot in which the error occurred is replaced with a free communication slot of the same carrier f1 while continuing communication in a communication slot in which no error has occurred. (503). Then, the communication is restarted in the two communication slots, the slot in which the communication is continued and the new slot (504).

FIG. 6 is a diagram for explaining the radio channel switching operation according to the present embodiment. In this example, when a failure occurs in one communication slot, a communication slot in which an error has not occurred is continued as it is while a communication slot in which an error has occurred is switched to a free communication slot of another carrier. The communication is restarted using the carrier.

That is, when communication is performed using two communication slots on the carrier f1 (601), 1
When a failure occurs in one of the communication slots and the error continues more than a specified number of times (602), the communication slot in which the error has occurred is replaced with a free carrier f2 different from the carrier f1 while continuing communication in a communication slot where no error has occurred. (603). Then, the communication is restarted in the two communication slots of the slot in which the communication is continued and the same slot on the new carrier f2 (60).
4).

Here, before explaining the wireless channel switching processing in the present embodiment, advantages / disadvantages of the above-described wireless channel switching method will be described. (I) Radio channel switching method by carrier switching including communication slot during communication shown in FIG. 4 (II) Communication slot during communication shown in FIG. (III) The wireless channel switching method in which the communication slot during communication shown in FIG. 6 is continued and the faulty communication slot is switched to the same slot on a different carrier as shown in FIG. Although it is optimal when communication is always performed using a plurality of slots, it is possible that all data communication is temporarily interrupted.

The method according to the above (II) reduces the communication line capacity, but allows communication at all times, and the movement of only the slot reduces the load of the processing of wireless channel switching. Although it is advantageous in the aspect, it is disadvantageous in that it is susceptible to mutual interference due to adjacent slots.

In the method according to the above (III), although the communication line capacity is reduced, communication can always be performed, and since the carrier is different, mutual interference is higher than in the above (II) using the adjacent slot. This is advantageous in that it is less susceptible to noise, but disadvantageous in that the processing load after wireless channel switching increases.

Next, based on these advantages / disadvantages, the wireless channel switching processing in the present embodiment will be described. FIG. 7 is a flowchart illustrating the wireless channel switching processing according to the present embodiment.

First, when an error occurs in one communication slot during communication using two communication slots (Yes in step S701). After recognizing the error,
A situation determination is performed (step S702). Then, according to the determination result, it is determined which pattern of steps S703 to S708 is used to select the wireless channel switching process. Here, for example, “I” in step S703
If “II → III” is selected, first, the switching processing is performed in the order of the wireless channel switching processing I → II → III until two communication slots become available. The same applies to steps S704 to S708. .

The above steps S703 to S70
Step S702 determines which of the switching processes 8 is to be selected.
For example, as a factor for selecting step S703, there is a case where it is desired to always secure the capacity of the communication line by the two communication slots and reduce the load in the switching process. Communication may be performed.

Next, as a result of performing any one of the switching processes in steps S703 to S708, it is determined whether two communication slots can be used (step S709). Here, if usable, communication processing for two communication slots is performed (step S71).
0), it is determined whether or not to continue the communication (step S713). If not, the process returns to step S701,
The above processing is repeated.

If two communication slots cannot be used in step S709, the communication is further restricted to two.
It is determined whether the communication is limited to communication in one communication slot (step S711). Here, if it is limited, the process returns to step S702, the situation is determined again, the wireless channel switching process is performed, and the above process is repeated until two communication slots become available.

On the other hand, if it is determined in step S711 that the communication can be performed by one communication slot, the communication processing for one communication slot is performed (step S712), and the process proceeds to step S713.

As described above, it is possible to minimize the increase of the communication line capacity in the non-voice communication and the decrease of the communication line capacity when the radio line of the single communication slot is deteriorated, and to cope with the situation of the non-voice communication. It is possible to flexibly select and execute a communication method.

In the above-described embodiment, the PHS is used as a wireless medium as an example of a wireless communication system that realizes multi-access and duplex communication using a plurality of slots allocated to a plurality of carriers. The present invention is also applicable to a wireless communication system that realizes multi-access and duplex communication using a plurality of slots allocated to a carrier, a PDC, a PCS, a DECT, a frequency hopping wireless LAN, and the like.

The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but it can be applied to a single device (for example, a copier, a facsimile). Device).

Further, an object of the present invention is to supply a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (CPU or MP) of the system or apparatus.
It goes without saying that U) can also be achieved by reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided on a function expansion board inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instructions of the program code. It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

[0037]

As described above, according to the present invention,
A single wireless terminal can simultaneously connect a plurality of wireless channels, and even if a problem occurs due to interference of a wireless line and the wireless communication line cannot be secured, an appropriate wireless communication line cannot be secured. By selecting the wireless channel switching process, services including the running application can be smoothly performed.

[0038]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a wireless communication system according to an embodiment.

FIG. 2 is a diagram illustrating a usage state of a communication slot of the PHS data communication system according to the embodiment.

FIG. 3 is a diagram illustrating mapping of a physical slot on a carrier in a PHS.

FIG. 4 is a diagram for explaining a wireless channel switching operation according to the present embodiment.

FIG. 5 is a diagram for explaining a wireless slot switching operation according to the embodiment.

FIG. 6 is a diagram for explaining a wireless channel switching operation according to the present embodiment.

FIG. 7 is a flowchart illustrating a wireless channel switching process according to the embodiment.

[Explanation of symbols]

 101 PHS wireless communication terminal (PS) 102 PHS wireless communication base station (CS) 103 ISDN network 104 Data communication equipment (PC)

Claims (9)

[Claims] 1. A wireless communication system comprising: a wireless base station connected to a digital line; and a wireless terminal that communicates with the wireless base station via a plurality of wireless channels. Communication means for performing communication by a plurality of wireless channels using a plurality of communication slots obtained by time-dividing each of the carriers, and switching means for switching the wireless channel according to a communication state during communication by the communication means. A wireless communication system comprising: 2. The method according to claim 1, wherein the switching unit selects a channel switching method according to a communication state from a plurality of channel switching methods when the communication slot performing communication becomes unavailable due to interference of a wireless communication line. The wireless communication system according to claim 1, wherein the communication slot of the wireless channel is switched according to the channel switching method performed. 3. The wireless communication method according to claim 2, wherein one of the channel switching methods is a channel switching method for performing carrier switching to the same empty carrier capable of securing the number of wireless channels in use. system. 4. The method according to claim 2, wherein one of the channel switching methods is a channel switching method in which a communication slot is switched to an empty slot in the same carrier in which the number of used radio channels can be secured. Wireless communication system. 5. The method according to claim 2, wherein one of the channel switching methods is a channel switching method for switching a communication slot to the same slot in a different carrier capable of securing the number of radio channels in use. Wireless communication system. 6. A wireless communication method for a wireless communication system comprising a wireless base station connected to a digital line and a wireless terminal communicating with the wireless base station via a plurality of wireless channels, comprising: A communication step of performing communication through a plurality of wireless channels using a plurality of communication slots obtained by time-dividing each of the allocated plurality of carriers, and switching the wireless channel according to a communication state during communication in the communication step And a switching step. 7. The switching step includes, when a communication slot performing communication becomes unavailable due to interference of a wireless communication line, selecting a channel switching method according to a communication situation from a plurality of channel switching methods. 7. The wireless communication method for a wireless communication system according to claim 6, wherein a communication slot of the wireless channel is switched according to the channel switching method. 8. A wireless communication apparatus for communicating with a wireless base station connected to a digital line by using a plurality of wireless channels, wherein the plurality of carriers are obtained by time-dividing each of the plurality of carriers assigned to the wireless line. A wireless communication apparatus comprising: a communication unit that performs communication using a plurality of wireless channels using slots; and a switching unit that switches the wireless channel according to a communication state during communication by the communication unit. 9. The switching means selects a channel switching method according to a communication condition from a plurality of channel switching methods when a communication slot performing communication becomes unavailable due to interference of a wireless communication line. The wireless communication apparatus according to claim 8, wherein the communication slot of the wireless channel is switched according to the channel switching method performed.