JP2003199145A - Switching system selecting method, base station apparatus, and communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system with a plurality of communication channels and switching systems that can avoid congestion and enhance communication quality. <P>SOLUTION: In the communication system where a base station apparatus and a plurality of communication terminals can make communication with each other by selecting both kinds of packet switching system and line switching system or using them at the same time, a switching system decision section 14 provided to the base station apparatus decides the number of channels used for the packet switching system and the line switching system according to the communication quality (a call loss rate, an error rate, an S/N in the line switching system and a transmission delay time, the number of times of packet collision, and the number of times of packet retransmission in the packet switching system) monitored by the base station or the communication terminal, a control physical channel generating section 15 generates a corresponding control signal and transmits it to the communication terminal. Or the communication terminal may have a decision right of the number of channels used for the packet switching and the line switching. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a mobile phone and a PHS.
As described above, the present invention relates to a switching method changing method, a base station apparatus and a communication terminal apparatus in a communication method for communicating between a base station apparatus and a communication terminal apparatus.

[0002]

2. Description of the Related Art FIG. 3 shows a simplified configuration example of a mobile communication network. FIG. 3 shows an example in which there are three communication terminal devices, and the base station device 4, the communication terminal device 1 to the communication terminal device 3 are used.
Is an example of communication using radio waves. On the other hand, there is a digital car telephone system (hereinafter abbreviated as "PDC") as an example of a communication system provided with both the circuit switching system and the packet switching system. The technical standards of this PDC are described in the document "Digital Car Phone System (RCR STD-27F)" issued by the Association of Radio Industries and Businesses.

As shown in FIG. 4, the functional channels of PDC are classified into an information channel TCH for transferring user information and a control channel CCH, and the CCH further comprises a broadcast channel BCCH, a common control channel CCCH, and a user packet channel UPCH. Common access channel CAC
And a user-specific channel USC having an associated control channel ACCH. The common control channel CCCH further includes a paging channel PCH and a dedicated cell channel SCCH, and the associated control channel ACCH is a low speed ACCH (SACCH) and a high speed ACH.
Consisting of CCH (FACCH) (RCR STD-27F standard diagram
See 4.1.4.1-1). In addition to the channels shown in FIG. 4, there is an RCH formed of housekeeping bits, but the description thereof is omitted because it is not directly related to the present invention.

FIG. 5 shows an example of correspondence between PDC physical channels and functional channels (see Table 4.1. Of RCR STD-27F standard document).
See 4.2-1). As shown in this figure, there are a broadcast channel BCCH, a paging channel PCH, an individual cell channel SCCH as downlink control physical channels, and an individual cell channel SCCH as uplink control physical channels. Further, there are a user information transfer channel TCH, a low speed associated control channel SACCH, a housekeeping channel RCH and a high speed associated control channel FACCH as downlink and uplink communication physical channels, and a user packet channel as downlink and uplink packet communication physical channels. There is UPCH.

An example of a PDC frame structure is shown in FIG.
R STD-27F standard document, page 37, Figure 4.1.4.2-1). In FIG. 6, the control physical channel, the communication physical channel, and the packet communication physical channel are TDMA (time division multiple access system).
In the example shown in FIG. As shown in this figure, when the control physical channel and the communication physical channel coexist, when the communication physical channel only, when the control physical channel, the communication physical channel and the packet communication physical channel coexist, the control There are various forms such as a case where the physical channels for packet communication and the physical channels for packet communication are mixed, and a case where only the physical channels for packet communication are provided.

BC in the PDC control physical channel
An example of arrangement of CH (broadcast channel), PCH (paging channel), and SCCH (dedicated cell channel) is shown in FIG.
(See Figure 4.1.4.2-2 on page 37 of RCR STD-27F standard document). FIG. 7 shows an example of BCCH, SCCH, and PCH allocation in the control physical channel in the example in which the control channels are allocated to slot 0 and slot 3.

An example of the signal format of the physical channel for communication of PDC is shown in FIG. 8 (see FIG. 4. of RCR STD-27F standard document).
See 1.4.2-2). It is composed of a user information transfer channel TCH for transmitting voice information from a user and a SACCH (low speed ACCH). Here, the ACCH is called an associated control channel, and is a point-to-point bidirectional control channel associated with the TCH, which transmits signaling information and the like.

An example of the basic structure of the control physical channel showing the structure of the PDC common access channel is shown in FIG. 9 (RC
(See Figure 4.1.10.2-1 of the R STD-27F standard document). FIG. 9 shows the configuration of the control physical channel shown in FIG. 7 more specifically. The structure of the BCCH channel in Fig. 9 is shown in Fig. 10 as an example of the structure of the BCCH channel of the PDC (Fig. 4.1.10.2- of the RCR STD-27F standard document).
See 2). Details of the signal transmitted by this BCCH are shown in FIGS. 11 and 12 as an example of the contents of the BCCH in the PDC (page 262, 4.3. Of RCR STD-27F standard document).
See section 5.2.23 Broadcast information).

The operation of the PDC when the mobile station (communication terminal device) is powered on is as follows. When the mobile station powers on, it captures the perch channels in the zone in which it is located, so the mobile station scans the carriers of the channels that are uniquely stored by the mobile station and creates a level-ordered table. After that, synchronization with slot 2 and slot 5 (see FIG. 6 for slot numbers) is carried out in order from the highest level carrier, and it is confirmed that the channel is a common control channel and BCCH is received (for the slot of BCCH in the control physical channel). (See FIG. 7), and if it can stand by, it enters the stand-by state. PD
In C, the information on the structure of the physical channel for packet communication is notified by the BCCH of the control physical channel in the same cell, the idle unit in the UPCH of the physical channel for packet communication, and the layer 3 signal. The mobile station determines the structure of the physical channel for packet communication based on this information and the information stored in the mobile station (see RCR STD-27F standard document, page 105, 4.1.10.3.2).

The packet channel structure information in FIG. 11 is, as shown in FIG. 13, 5 octets of information.
The number of physical channels for packet communication in the cell formed by the base station (0 to 9), the subframe number of the leading call notification group (0 to 35), the number of common information notification subframes in the superframe, 1 It consists of sub-frame length, etc. for grouping and arranging call notifications within a super frame (RCR STD-27F standard document page 296, 4.3.5.3.3.
39). The slot used by the packet channel can be changed by changing these values. That is, it is possible to change which frequency and slot are used as the packet switching channel (UPCH) and the circuit switching channel (TCH) by changing the signal included in the BCCH transmitted from the base station to the mobile station. Is.

The manner in which the physical channels are switched in this manner is, for example, in FIG. 6 described above, in the case where "control physical channels and communication physical channels coexist", control physical channels, communication physical channels (circuit switching),
And when packet communication channels (1 slot each) coexist (this is referred to as case 1) to physical control channels and packet communication channels (2 slots) coexist (this is referred to as case 2) It can be illustrated as switching to.

When the base station changes the channel structure in this way, the information must be transmitted to all mobile stations in the cell. However, the mobile station does not always receive the BCCH. Therefore, the base station needs to prompt the subordinate mobile stations to receive the BCCH. When instructing the mobile station to receive the BCCH from the base station, for example, it is possible to use the PCH (Digital Radio Communication System for Public Services RCR ST).
D-39B standard document, page 935, see 4.3.8.10.2 BCCH reception).

As described above, for example, in the PDC, the radio channel can be divided into UPCH for packet-switched transmission and TCH for circuit-switched transmission, and the frequency and time slot of the channel can be changed. Has become. This makes it possible to change the ratio of channels used for packet switching and circuit switching. However, in a conventional communication system represented by PDC, a call once a communication link is established by circuit switching is
The switching method cannot be changed to packet switching on the way, and conversely, a call that started communication by packet switching cannot be changed to circuit switching on the way of communication. That is, if attention is paid to a specific call, it is possible to select either packet switching or circuit switching only at the start of communication, but it cannot be changed after communication is established.

Further, when the input signal of the base station device or the communication terminal device can be transmitted only by circuit switching or only by packet switching depending on its nature (for example, voice, data, image, still image, moving image). There is. In PDC and the like, a common band is divided and used for circuit switching and packet switching. For this reason, many calls that can be transmitted only by packet switching occur, and the packet switching channel is congested even when there are extra channels for circuit switching. For example, voice is usually line switched. In circuit switching, in which a channel is fixedly assigned to a specific user at a certain time, for example, when voice is transmitted by circuit switching, it is necessary to reserve a channel even in a silent section of voice communication, so that the channel is wasted. Occurs. On the other hand, such waste does not occur in packet switching, but the transmission delay time increases due to frequent retransmission requests due to packet collisions due to increased traffic, and signal quality deteriorates. This is because until now, it was not possible to constantly observe the signal quality in packet switching and circuit switching, and to automatically divide the circuit switching channel and packet switching channel in real time so that the respective communication qualities are compatible. Is.

[0015]

As described above, in the conventional communication system, when the bandwidth is divided and allocated by the packet switching and the circuit switching, the call traffic and the circuit which are suitable for the packet switching which is currently occurring are generated. By not matching the ratio of call traffic suitable for switching, packet switching is of sufficiently good quality, but the number of channels for circuit switching is insufficient, resulting in a poor call loss rate for circuit switching, and vice versa. Has a high number of channels, so the loss rate is good,
Since there are few channels for packet switching, there was a decrease in throughput due to packet collision and an increase in transmission delay time due to retransmission. Further, even when changing the number of channels used for circuit switching and packet switching, there is a drawback that the base station cannot change the switching method until the call being communicated by the switching method ends.

The present invention has been made in view of the above,
The purpose is to prevent congestion and accompanying deterioration of transmission signal quality due to traffic mismatch due to packet switching and circuit switching calls with respect to the band division ratio of packet switching and circuit switching, and to enable simultaneous transmission. This is to increase the number of channels, improve the reliability of communication lines, and improve the quality of transmitted signals.

[0017]

In order to achieve the above object, according to the switching method selection method of the present invention, a base station device and a plurality of communication terminal devices both share a plurality of communication channels, In a communication system in which a packet switching system and a circuit switching system can be used simultaneously or by switching for each communication channel for mutual communication performed by a base station device and a plurality of communication terminal devices using the base station device, Alternatively, the communication terminal device monitors the communication quality, and the number of channels used for circuit switching and packet switching is changed by the base station device or communication terminal device having the switching system decision right according to the communication quality. . Further, the communication quality monitored by the base station device or the communication terminal device,
Block loss rate, error rate, S / of received signal in circuit switching system
N, the transmission delay time in packet switching, the number of packet collisions or the number of packet retransmissions, and any one or more of them.

Further, any input signal of the base station device or the communication terminal device is transmitted to a communication partner either simultaneously by the packet switching system and the circuit switching system or by any switching system. It is a thing. Furthermore, when the base station apparatus or communication terminal apparatus having the switching system decision right decides to change the number of channels used for circuit switching and packet switching according to communication quality, the base station apparatus uses a control signal. To notify the communication terminal device of the usage of the exchange method, and perform communication from the base station device to the communication terminal device and communication from the communication terminal device to the base station device according to the usage method of the communication channel. It is a thing. Furthermore, when the base station device is started up, the base station device determines each switching method to be used in a plurality of communication channels, and uses the switching method to be used for each communication channel by using the control channel. Informing the terminal device, communication from the base station device to the communication terminal device and communication from the communication terminal device to the base station device are performed according to the usage method of the communication channel determined by the base station device. is there. Furthermore, when the base station apparatus and any one of the communication terminal apparatuses are performing communication, when a change in the exchange method of the communication channel in communication is notified, the exchange method of the channel in communication. Is changed to the changed exchange method. Furthermore, when the base station apparatus and any one of the communication terminal apparatuses are performing communication, when a change in the exchange method of the communication channel in communication is notified, the exchange method of the channel in communication. In order to prevent a momentary interruption of communication due to the change of the switching method when changing the switching method to the changed switching method, the communication is temporarily performed by both the packet switching method and the circuit switching method.

Furthermore, in the base station apparatus of the present invention, both the base station apparatus and the plurality of communication terminal apparatuses share a plurality of communication channels, and the base station apparatus and the plurality of communication terminal apparatuses are used by using the communication channels. A base station device used in a communication system capable of simultaneously or switching the packet switching system and the circuit switching system for each communication channel in mutual communication performed by, and means for monitoring communication quality, A means for deciding whether to change the number of communication channels used for circuit switching and packet switching according to the communication quality obtained by the means for monitoring the communication quality or the communication quality notified from the communication terminal device; A corresponding control signal is generated based on the determination by the determining means to change the number of communication channels used for circuit switching and packet switching, and the plurality of communication And has a means for notifying the end device.

Furthermore, another base station apparatus of the present invention is
The base station device and the plurality of communication terminal devices share a plurality of communication channels together, and packets for each communication channel are used for mutual communication between the base station device and the plurality of communication terminal devices using the communication channel. A base station device used in a communication system capable of simultaneously or switching between a switching system and a circuit switching system, and changing the number of communication channels used for circuit switching and packet switching notified from the communication terminal device. It has means for receiving a change instruction signal, means for generating a corresponding control signal based on the change instruction signal, and means for notifying the plurality of communication terminal devices of the generated control signal.

Furthermore, in the communication terminal device of the present invention, the base station device and the plurality of communication terminal devices both share a plurality of communication channels, and the base station device and the plurality of communication terminal devices are used using the communication channels. A communication terminal device used in a communication system capable of simultaneously or switching a packet switching system and a circuit switching system for each communication channel for mutual communication performed by, and means for monitoring communication quality, Means for determining whether to change the number of channels used for circuit switching and packet switching according to the communication quality;
A means for generating a change instruction signal for changing the number of communication channels used for circuit switching and packet switching based on the determination made by the determining means to change the number of communication channels used for circuit switching and packet switching; Means for notifying the base station device of the instruction signal.

According to the switching method selecting method, the base station device and the communication terminal device of the present invention, the base station device and the plurality of communication terminal devices both share a plurality of communication channels, and the communication channels are shared. In a communication system in which the base station apparatus and a plurality of communication terminal apparatuses are used for mutual communication, the packet switching method and the circuit switching method can be used simultaneously or by switching for each communication channel. Each of the station and the communication terminal device has communication quality (call loss rate, error rate, S / S of transmission signal in the circuit switching system).
N, the transmission delay time in packet switching, the number of packet collisions, or the number of packet retransmissions 1) is monitored, and the number of channels used for circuit switching and packet switching is determined according to the communication quality. Alternatively, the communication terminal device is changed. As a result, it is possible to prevent congestion and deterioration of transmission signal quality caused by the traffic mismatch due to the packet switching call and the circuit switching call with respect to the band division ratio of the packet switching and the circuit switching. In addition, it is possible to increase the number of communication channels that can be simultaneously transmitted, increase the reliability of communication lines, and improve the quality of transmission signals.

[0023]

DETAILED DESCRIPTION OF THE INVENTION An example of an embodiment of the present invention will be described below with reference to the accompanying drawings. First, a conceptual explanation of the exchange method selection method of the present invention will be given with reference to FIGS. In FIG. 3, a control channel signal is transmitted from the base station device 4. In FIG. 6, the situation corresponds to the case where the control signal is transmitted using the control physical channel in, for example, “when the control physical channel and the communication physical channel are mixed”. There is also a case (case 1) in which control physical channels, communication physical channels (circuit switching), and packet communication channels (one slot each) coexist. Further, there is a case (case 2) in which the control physical channel and the packet communication channel (2 slots) are mixed. The switching method selection method of the present invention is performed by the base station, for example, switching from case 1 to case 2, or case 2
The base station or one or a plurality of communication terminal devices monitors the communication quality, and the base station switches the number of channels used for circuit switching and packet switching according to the communication quality. It is a thing. Here, the switching operation itself is performed by the base station, but the switching decision right (switching scheme decision right) can be given not only to the base station but also to a mobile station that can have the switching decision right. . When the mobile station has the switching system decision right, the control signal for performing the switching operation may be notified from the mobile station to the base station performing the switching operation. The communication quality to be monitored may be, for example, a call loss rate in a circuit switching system, an error rate, an S / N ratio of a transmission signal, a transmission delay time in packet switching, the number of packet collisions, the number of packet retransmissions, etc. It is also possible to monitor the quality-related value and to decide whether or not to carry out the switch. Alternatively, the determination may be made using a plurality of types of information among the above communication qualities.

FIG. 1 is a principal block diagram showing an example of the configuration of a communication apparatus capable of executing such a switching method selecting method of the present invention. Here, the base station device is shown. In FIG. 1, a transmission signal of a communication channel and a signal of a control physical channel generated by a control physical channel generation unit 15 are input to a transmission unit 11 and transmitted to a communication terminal device. The signal of the communication channel transmitted from the communication terminal device is received by the receiving unit 12, and the signal of the control channel is input to the control receiving unit 13. The switching system determination unit 14 monitors the communication quality, determines whether to change the ratio of channels used for packet switching and circuit switching based on the result, and sends the determination result to the control physical channel generation unit 15. Notice. The control physical channel generation unit 15 generates control information (BCCH or the like) indicating the usage of the switching system used for each corresponding communication channel based on the information from the switching system determination unit 14, and the SCCH or the like. And the information of the control physical channel of the transmitter 1.
Output to 1.

FIG. 2 is a flow chart showing the flow of processing in the base station apparatus. When the power is turned on,
First, on the basis of a preset initial value, the control physical channel generation unit 15 generates a BCCH (S1), and other control channel information is generated (S1).
2). Then, the communication quality is monitored (S3), and it is determined whether or not it is necessary to change the ratio of channels used for packet switching and circuit switching based on the result (S4). As a result, when there is no need to change (when the result of S4 is NO), the communication quality monitoring is resumed. When it is determined that the change is necessary (the result of S4 is YES), the usage method of packet switching or circuit switching is changed for each communication channel (S5), and the process proceeds to step S1. Returning to this, the control information such as BCCH (control information indicating the usage of the exchange method) corresponding to the change result is generated.

As described above, the communication quality to be monitored includes the call loss rate, error rate, and
There are S / N of transmission signals, transmission delay time in packet switching, number of packet collisions, number of packet retransmissions, and the like. This monitoring may be performed by the base station itself or by the communication terminal device. When the communication terminal device monitors,
The monitoring result may be notified to the base station via a control channel or the like, or if the communication terminal device is a mobile station having the switching decision right, the switching decision is made according to the monitoring result. You may be allowed to do. For example, the call loss rate of the circuit switching method can be obtained from the control receiving unit 13 in the base station, and the error rate and the S / N of the received signal can be obtained by the receiving unit 12 of the base station or the communication terminal device. It can be obtained from the receiver. The transmission delay time in the packet switching is
It can be obtained from the time when the packet is input to the packet transmitter and the time when the corresponding ACK or NACK is received by the packet receiver. The number of packet collisions can be obtained from the fact that the received signal power is equal to or higher than a predetermined value and the time ratio of the section in which the bit error rate is higher than the predetermined value is higher than the predetermined value. The number of packet retransmissions can be acquired from the number of retransmissions counting unit in the packet transmitter. In this way, whether or not it is necessary to change the communication line allocation in the exchange method determination unit 14 based on the communication quality information acquired by the base station device or the communication terminal device, and when Determine whether to set the switch.

For example, as a method for setting this switching, (number of collisions per unit time) / in packet switching /
Let (total number of packets generated per unit time) be N,
When the call loss rate for circuit switching is P, and the base station or mobile station that has the right to decide the switching method is N <P, the number of channels for packet switching is reduced, and this is assigned to the channel for circuit switching. Increase the number of channels, N>
On the contrary, when P, the number of channels for packet switching is increased. This makes it possible to prevent the communication quality of either one of the circuit switching and the packet switching from being significantly deteriorated. The method of setting this switching is arbitrary, for example, switching when N <P or switching when 2N <P is established. What manages the communication system is circuit switching and packet switching. It can be freely decided by the idea of the grade of exchange service.

Until now, such switching has not been carried out or has been carried out manually, and therefore, when the traffic of either one of the switching methods suddenly increases or decreases significantly, it is not possible to flexibly cope with it, resulting in communication quality. It was difficult to avoid congestion and congestion. In addition, it was necessary to allocate personnel exclusively for switching. On the other hand, according to the switching method selection method of the present invention, the number of channels used for circuit switching and packet switching can be changed according to the communication quality, and deterioration of signal quality can be prevented and at the same time. It is possible to increase the number of communication channels that can be transmitted, increase the reliability of communication lines, and improve the quality of transmission signals.

When the base station switches the switching system from the circuit switching to the packet switching, the communication terminal device performing communication is notified that the switching system is changed by using, for example, SACCH as a control signal. be able to. However, since the SACCH cannot be used for the communication terminal device which is waiting for a call from the base station by circuit switching or is about to call the base station, the SACCH cannot be used for these by the control signal transmitted by the BCCH. Notify that the exchange method will be changed. For example, in switching from circuit switching to packet switching, the base station switches to the terminal device using the control signal such as SACCH shown in FIG. 8 for the terminal device in communication before switching the switching method. Can be notified that something happens. In addition,
When changing the structure of the communication physical channel (see FIG. 6 for an example of the frame structure), the contents of BCCH are changed to B
The fact that the content of the CCH has changed is notified to the terminal device that is not communicating using the PCH. The control signal also includes a signal transmitted from the base station to the communication terminal apparatus in a packet including the control signal, the signal indicating that the switching method is changed from packet switching to circuit switching. In this way, the base station or communication terminal device monitors the communication quality,
When the base station or communication terminal device having the switching system decision right decides to change the number of channels used for circuit switching and packet switching according to the communication quality, the base station uses the switching system by using a control signal. Is notified to the terminal device, and the communication from the base station to the terminal and the communication from the terminal to the base station are performed according to the usage of the communication channel determined by the base station.

Next, another embodiment of the present invention will be described. The aforementioned switching is necessary when the traffic of either circuit switching or packet switching increases. Therefore, when switching is performed, new calls are restricted, and switching is performed when all of the channels to be switched are vacant due to the termination of all communication that is currently in progress. When it occurs, congestion occurs due to new incomplete call that occurs due to call restriction. Therefore, it is desirable that the switching of the switching system can be performed without interruption during the current communication between the base station apparatus and generally a plurality of communication terminal apparatuses.

Therefore, in this embodiment, an arbitrary input signal of the base station apparatus or the communication terminal apparatus is either the base station apparatus or the communication terminal apparatus at the same time by the packet switching method and the circuit switching method or by any one of the switching methods. To be transmitted to the other party. An example of an arbitrary signal is a voice signal. In this case, the voice signal can be communicated by both circuit switching and packet switching. In addition, data and image information can be communicated through either the circuit switching channel or the packet switching channel. Then, when a change in the exchange method of the channel in communication is notified during communication between the base station apparatus and any one of the communication terminal apparatuses, the exchange method of the channel in communication is changed. Change to a different exchange method.

For example, when the base station tries to change the channel used by a call that was initially performing voice communication by circuit switching to a channel for packet switching, a control channel signal for notifying the usage of the switching method is sent. The base station originates, the terminal device receives it, and the base station and the communication terminal device change the transmission of the voice signal during communication to packet switching. The terminal device that receives the notification starts communication in packet switching, or the base station performs packet switching in order to continue communication with the base station device that was performing circuit switching in packet switching, for example. Wait for the signal to be transmitted.

However, it is difficult to switch the switching method for a call during communication without interruption. For example, in circuit switching, call setting must be performed prior to starting communication. If the packet switching is suddenly switched to the circuit switching, communication is interrupted because the information signal to be sent cannot be transmitted during the call setup in the circuit switching. Then, still another embodiment of the present invention capable of eliminating such inconvenience will be described. In this embodiment, when the base station apparatus and any one of the communication terminal apparatuses are performing communication and a change in the exchange method of the channel in communication is notified, When changing the switching method of the communication channel to the changed switching method, in order to prevent instantaneous interruption of communication due to the change of the switching method, both the packet switching method and the circuit switching method are temporarily switched. By performing the communication by the method, the base station can change the switching method from the circuit switching to the packet switching or from the packet switching to the circuit switching without interrupting the communication on the way. Note that when switching from packet switching to circuit switching, it is necessary to temporarily communicate simultaneously using both switching methods to prevent interruptions during the call setup time of circuit switching. It is not always necessary to perform communication by both exchange methods at the time of switching.

As described above, the exchange system can be decided by the base station or the communication terminal device having the exchange system decision right.
However, when only the communication terminal device has the right to decide the exchange method, the communication method having the exchange method decision right is not determined because the exchange method is undecided when the base station device is powered on. On the other hand, since it is unknown which exchange method is used and which channel is used to perform communication for switching the exchange method, the communication system as a whole may not be activated. Therefore, in order to eliminate such an inconvenience, as described with respect to step S1 in FIG. 2, when the base station apparatus is started by turning on the power, the packet switching is performed by the setting temporarily stored in the base station apparatus. The channel used for circuit switching is set.

Further, when the communication terminal device has the switching system decision right, the control signal for instructing switching from the communication terminal device may be notified to the base station device as described above, or A control signal may be sent to the exchange method determination unit 14 provided in the base station device to change the algorithm for determining whether or not to change the exchange method.

As described above, according to the switching method selection method, the base station apparatus and the communication terminal apparatus of the present invention, by changing the ratio of the number of channels used for both the packet switching and the circuit switching methods according to the communication quality, It is possible to prevent the communication quality of only one of the circuit switching and the packet switching from deteriorating unilaterally, and prevent channel congestion using the switching method. As a result, it is possible to flexibly deal with congestion and deterioration of signal quality due to fluctuations in traffic, as compared with the conventional method in which the number of channels is fixed.

[0037]

In the conventional communication systems capable of circuit-switched and packet-switched communication, a call for which a communication link has once been established by circuit switching cannot change its switching method to packet switching midway. On the contrary, it was not possible to change a call that started communication by packet switching to circuit switching during communication. Therefore, in a communication system in which a common band is divided and used for circuit switching and packet switching, even if there are many calls that can be transmitted only by packet switching and there are extra channels for circuit switching, the packet switching channel Is congested, the number of retransmissions increases and throughput decreases. On the other hand, by applying the present invention, even when the number of calls of one of the packet-switched and circuit-switched channels is high and the communication quality is deteriorated, when the other one is low, By allocating a part to either one of the above-mentioned exchange methods, it becomes possible to avoid deterioration of signal quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of a base station apparatus in which a switching method selection method of the present invention is executed.

FIG. 2 is a flowchart showing a processing flow of a base station device in which the switching method selection method of the present invention is executed.

FIG. 3 is a schematic diagram showing a simplified configuration example of a mobile communication network.

FIG. 4 is a diagram showing a PDC channel configuration (functional channels).

FIG. 5 is a diagram showing an example of correspondence between PDC physical channels and functional channels.

FIG. 6 is a diagram showing an example of a PDC frame configuration.

FIG. 7: BCC in control physical channel of PDC
It is a figure which shows the example of arrangement | positioning of H, PCH, and SCCH.

FIG. 8 is a diagram showing an example of a signal format of a physical channel for communication of PDC.

FIG. 9 is a diagram showing an example of a basic structure of a control physical channel showing a structure of a PDC common access channel.

FIG. 10 is a diagram showing an example of a structure of a BCCH channel of PDC.

FIG. 11 is a diagram showing contents of broadcast information message of PDC.

[Fig. 12] Content of PDC broadcast information message (continued)
FIG.

FIG. 13 is a diagram showing an example of packet channel structure information.

[Explanation of symbols]

1-3 communication terminal device 4 base station equipment 11 Transmitter 12 Receiver 13 Control receiver 14 Exchange method determination unit 15 Control physical channel generator

Claims (10)

[Claims] 1. A base station device and a plurality of communication terminal devices,
Both share a plurality of communication channels, and a base station apparatus and a plurality of communication terminal apparatuses use the communication channels for mutual communication, and the packet switching method and the circuit switching method are used simultaneously or by switching for each communication channel. In a communication system capable of performing the above, the base station device or the communication terminal device has a switching system decision right to monitor the communication quality and determine the number of channels used for circuit switching and packet switching according to the communication quality. Alternatively, a switching method selection method is characterized in that the communication terminal device is changed. 2. The communication quality monitored by the base station apparatus or the communication terminal apparatus is a call loss rate in a circuit switching system,
2. The switching method selection method according to claim 1, wherein any one or more of an error rate, S / N of a received signal, transmission delay time in packet switching, number of packet collisions and number of packet retransmissions. 3. An arbitrary input signal of the base station device or the communication terminal device is transmitted to a communication partner both simultaneously by a packet switching system and a circuit switching system or by any switching system. The method for selecting a replacement method according to claim 1. 4. When the base station apparatus or communication terminal apparatus having the switching system decision right decides to change the number of channels used for circuit switching and packet switching in accordance with communication quality, the base station apparatus controls signal. To notify the communication terminal device of how to use the switching system, and to communicate from the base station device to the communication terminal device and from the communication terminal device to the base station device using the communication channel. The method according to claim 1, wherein the method is performed according to the method. 5. When the base station device is started up, the base station device determines each switching method to be used in a plurality of communication channels, and uses the switching method to be used for each communication channel by using a control channel. The communication terminal device is notified, and communication from the base station device to the communication terminal device and communication from the communication terminal device to the base station device are performed according to the usage method of the communication channel determined by the base station device. The method for selecting a switching method according to claim 1, wherein: 6. When the base station apparatus and any one of the communication terminal apparatuses are communicating with each other and a change in the exchange method of the communication channel in communication is notified, 6. The exchange method selection method according to claim 1, wherein the exchange method is changed to a changed exchange method. 7. When the base station apparatus and any one of the communication terminal apparatuses are communicating, and when a change in the exchange method of the communication channel in communication is notified, When changing the exchange method to the changed exchange method, in order to prevent instantaneous interruption of communication due to the change of the exchange method,
7. The switching method selection method according to claim 1, wherein communication is temporarily performed by both a packet switching method and a circuit switching method. 8. A base station device and a plurality of communication terminal devices,
Both share a plurality of communication channels, and a base station apparatus and a plurality of communication terminal apparatuses use the communication channels for mutual communication, and the packet switching method and the circuit switching method are used simultaneously or by switching for each communication channel. A base station device used in a communication system capable of monitoring communication quality, depending on communication quality obtained by the communication quality monitoring means and communication quality notified by the communication quality monitoring means. Means for deciding whether or not to change the number of communication channels used for circuit switching and packet switching, and to respond based on the decision from the deciding means to change the number of communication channels used for circuit switching and packet switching Generating a control signal to notify the plurality of communication terminal devices to the base station device. 9. A base station device and a plurality of communication terminal devices,
Both share a plurality of communication channels, and a base station apparatus and a plurality of communication terminal apparatuses use the communication channels for mutual communication, and the packet switching method and the circuit switching method are used simultaneously or by switching for each communication channel. A base station device used in a communication system capable of changing the number of communication channels used for circuit switching and packet switching notified from the communication terminal device; A base station apparatus comprising: means for generating a corresponding control signal based on the above, and means for notifying the plurality of communication terminal apparatuses of the generated control signal. 10. The base station device and the plurality of communication terminal devices share a plurality of communication channels together, and the base station device and the plurality of communication terminal devices use the communication channels for mutual communication. A communication terminal device for use in a communication system capable of using the packet switching system and the circuit switching system for each communication channel at the same time or in a switching manner, means for monitoring the communication quality, and circuit switching according to the communication quality. A means for determining whether to change the number of channels used for packet switching, and a circuit switching and packet switching based on the determination from the determining means that the number of communication channels used for circuit switching and packet switching is changed. It has a means for generating a change instruction signal for changing the number of communication channels to be used, and a means for notifying the base station device of the change instruction signal. Communication terminal equipment.