JPH08331035A - Communication method in radio communication system - Google Patents

Abstract

PURPOSE: To provide the communication method in the radio communication system in which a frequency resource is effectively utilized. CONSTITUTION: The system is made up of a radio base station 1, a radio terminal equipment 2 and an information server 6 sending information to the radio terminal equipment 2 via the radio bade station 1, and in the radio communication system, the radio base station 1 sends a signal through a broad band radio channel 3 at least to the radio terminal equipment 2 and the radio terminal station 2 sends a signal through a narrow band radio channel 4 to the radio base station 1. Then a control signal representing a reception start request and a reception end request is sent from the radio terminal equipment 1 to the radio base station 2 via the narrow band radio channel 4 and the radio base station 1 controls the allocation/release of the broad band radio channel 3 and the transmission start/end of information from the information server 6 to the radio terminal equipment 2 based on the control signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication method in a wireless communication system composed of a wireless base station, a wireless terminal and an information server.

[0002]

2. Description of the Related Art A wireless communication system composed of a wireless base station and a wireless terminal has been put to practical use as a mobile communication system. Conventionally, the communication service provided by the mobile communication system is mainly a voice call, which is immediate / two-way communication from the viewpoint of a wireless terminal. On the other hand, in recent years, with the progress of digital communication technology and computer technology, there is an increasing need for providing communication services such as data and images, which are media other than voice, by mobile communication. Especially in the case of video and other delivery services, which have been attracting attention in recent years,
Basically, a wireless terminal receives an information signal such as an image transmitted from an information server called a video server, and there is almost no need to send the information signal from the wireless terminal.
Therefore, it is inevitably necessary to increase the transmission rate of the wireless channel (downstream channel) from the wireless base station to the wireless terminal, and conversely, the wireless channel (upstream channel) from the wireless terminal to the wireless base station. May have a low transmission rate.

In such a communication service, an information signal continuously flows in a downlink channel, but in an uplink channel, a signal may be sent only at the time of communication control such as reporting communication parameters at the start / end of communication. However, in a conventional mobile communication system premised on a voice call, during communication, a so-called vertically symmetrical communication line having the same transmission frequency band is always ensured in the uplink channel and the downlink channel, so that the frequency band of the uplink channel is It will not be used effectively, and the utilization efficiency of frequency resources will decrease. This problem of frequency utilization efficiency is important especially in wireless communication with limited frequency resources.

In addition, when a communication service, which has been receiving attention recently, is converted to multimedia, the required communication mode varies depending on the type of service. For example, in an electronic publishing service, a control signal for a reception request is transmitted from a terminal to an information server, and an information signal is transmitted from the information server, but since these controls are performed sequentially, the signal is transmitted in both the up and down channels. It is not sent at the same time. On the other hand, VOD (Video On Dema) that distributes information signals of moving images such as movies, which are attracting attention as a new service.
nd: Video on Demand), the request may be made to change the information server that receives the information during the reception due to the change of the receiving channel, etc., so the uplink channel from the terminal to the base station can be accessed at any time. There is a need.

As described above, the conditions required for each communication service differ slightly, but in the conventional wireless communication system, communication is performed according to a fixed communication control procedure for each system. On the other hand, as a result of allocating a radio channel that is not necessary, or performing redundant control depending on the type of communication service and increasing control traffic, the utilization efficiency of frequency resources decreases.

[0006]

As described above, in the conventional wireless communication system, the vertically symmetrical radio frequency band is used for unidirectional information distribution in the radio transmission line between the radio base station and the radio terminal. Therefore, there is a problem from the viewpoint of effective use of frequency resources, and since a common communication control procedure is used for different required communication conditions for each communication service, useless radio channel allocation is performed depending on the type of communication service. However, there is a problem that the utilization efficiency of frequency resources decreases due to the increase of control traffic.

The present invention has been made to solve such conventional problems, and an object thereof is to provide a communication method in a wireless communication system capable of effectively utilizing frequency resources. To do.

[0008]

To achieve the above object, the present invention comprises a radio base station, a radio terminal, and an information server for transmitting information to the radio terminal via the radio base station, A communication method in a wireless communication system for transmitting a signal from a wireless base station to at least a wireless terminal via a wideband wireless channel, and transmitting a signal from the wireless terminal to a wireless base station via a narrowband wireless channel. A first communication method of the invention sends a control signal for a reception start request and a reception end request from a wireless terminal to a wireless base station via a narrowband wireless channel, and the wireless base station sends a wideband wireless channel based on the control signal. It is characterized by controlling allocation / deallocation of information and starting / ending transmission of information from the information server to the wireless terminal.

Further, in the second communication method of the present invention, while the wireless terminal is receiving the information from the information server through the wide band wireless channel, the information is transmitted to the wireless base station through the narrow band wireless channel. The wireless base station periodically sends a notification during reception indicating that it is being received, and if the wireless base station does not receive the notification during reception within a predetermined time, it transmits information from the information server to the wireless terminal. It is characterized by ending.

Further, the third communication method of the present invention is such that when the wireless terminal is receiving the information from the information server within a predetermined time from the time when it starts receiving the information from the information server via the wideband wireless channel. , If a notification during reception indicating that the information is being received is sent to the wireless base station via the narrow band wireless channel, and the wireless base station does not receive the notification during reception within the predetermined time. Ends the transmission of information from the information server to the wireless terminal, and when the reception notification is received within the predetermined time, the control signal of the reception end request from the wireless terminal via the narrow band wireless channel. The information transmission from the information server to the wireless terminal is continued until is received.

The fourth communication method of the present invention sends an identification signal for identifying a desired communication service type from a wireless terminal to a wireless base station via a narrow band wireless channel,
The radio base station is characterized by selecting a control procedure for communication between the radio base station and the radio terminal based on the identification signal.

Further, according to a fifth communication method of the present invention, an identification signal for identifying a desired communication service type is transmitted from a wireless terminal to a wireless base station via a narrow band wireless channel, and the wireless base station transmits the identification signal. It is characterized in that a control procedure for communication between the radio base station and the radio terminal is selected from a connection-type control procedure and a connectionless-type control procedure based on the identification signal.

[0013]

In the first communication method, since the control signals for the reception start request and the reception end request are transmitted from the wireless terminal to the wireless base station via the narrow band wireless channel, the wireless terminal having a small amount of transmission information transmits the wireless base station. The frequency band of the wireless transmission path to can be saved.

Further, in the radio base station, based on the control signal of the reception start request sent from the radio terminal, the control of allocation / release of the wideband radio channel from the radio base station to the radio terminal and the information server from the radio terminal are performed. In order to control the start / end of transmission of information to the wireless terminal, when the wireless terminal receives information from the information server, the wireless terminal need only send a control signal of a reception start request to the wireless base station once, Control traffic is reduced. In this way, the frequency band utilization efficiency is improved by saving the frequency band of the wireless transmission path from the wireless terminal to the wireless base station and reducing the control traffic.

In the second communication method, the wireless terminal is receiving information from the information server via the wideband wireless channel,
An information server for a wireless terminal when a receiving notification is periodically sent to a wireless base station via a narrow band wireless channel, and the wireless base station does not receive the receiving notification within a predetermined time. By ending the transmission of the information from the wireless terminal, it is possible to save the frequency band of the wireless transmission path from the wireless terminal having a small amount of transmission information to the wireless base station.

Further, since it is not necessary to specially send a control signal from the wireless terminal to the wireless base station at the end of reception, particularly when the receiving channel is switched, that is, the information server of the information provider is frequently changed. Since the number of times the control signal is sent out is small and the control traffic is reduced,
The utilization efficiency of the frequency band is improved.

In the third communication method, when the wireless terminal is receiving the information from the information server via the wideband wireless channel within a predetermined time from when the information is received, the narrowband wireless channel is used. When the wireless base station does not receive the receiving notification within a predetermined time, it notifies the wireless base station of the reception of the information via the wireless terminal. When the information transmission to the wireless terminal is completed and the reception notification is received within the predetermined time, the information server transmits the information to the wireless terminal until the control signal of the reception end request is received from the wireless terminal via the narrowband wireless channel. By continuing to transmit information to the wireless base station, it is possible to save the frequency band of the wireless transmission path from the wireless terminal having a small amount of transmission information to the wireless base station.

Further, in the case where the same channel is continuously used for a comparatively short period of time after switching the channel, as in the case of searching a TV screen in VOD, for example, the control of the reception end request is performed at each channel switching. Since it is not necessary to transmit a signal from the wireless terminal, control traffic is reduced and frequency band utilization efficiency is improved.

In the fourth communication method, communication between the wireless base station and the wireless terminal is performed based on an identification signal for identifying the type of communication service transmitted from the wireless terminal via the narrow band wireless channel in the wireless base station. By selecting the control procedure of (1), it is possible to prevent unnecessary control traffic from being increased by forming a useless radio channel or performing communication control unnecessary for the communication service that the wireless terminal is going to receive. , The utilization efficiency of frequency resources is improved. Further, it is possible to easily secure the communication quality according to the communication service.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a mobile radio communication system according to an embodiment of the present invention. This wireless communication system
It is composed of a wireless base station 1, a wireless terminal 2, a communication network 5 and an information server 6, and performs communication between the wireless base station 1 and the wireless terminal 2 in the direction from the base station 1 to the terminal 2 (downward direction). It is possible to form the wideband wireless channel 3 and the narrowband wireless channel 4 for communication in the direction (uplink direction) from the terminal 2 to the base station 1. The narrow band wireless channel 4 may be formed in the downstream direction.

Next, the configuration of each part of FIG. 1 will be described in more detail with reference to FIGS. The radio base station 1 has a wide band transmission circuit 11, a narrow band (transmission) reception circuit 12, a control unit 13, and a timer 14 as shown in the schematic configuration of FIG. The wideband transmission circuit 11 is controlled by the control unit 13 and transmits a signal to the wireless terminal 2 via the wideband wireless channel 3. The narrow band (sending / receiving) circuit 12 is controlled by the control unit 13, and the wireless terminal 2 is transmitted via the narrow band wireless channel 4.
To receive the signal from. When the narrow band wireless channel 4 can be formed in the downlink direction, the narrow band (sending) receiving circuit 12 is provided with a transmitting / receiving function. Control unit 13
Is connected to the communication network 5, and the information server 6 is connected via the communication network 5.
The control signal is transmitted to and the broadband information signal from the information server 6 is received. The timer 14 will be described later.

The radio terminal 2 has a wide band reception circuit 21 and a narrow band transmission (reception) circuit 2 as shown in FIG.
2. It has a controller 23 and a timer 24. The wideband receiving circuit 21 is controlled by the controller 23 and receives a signal transmitted from the wireless base station 21 via the wideband wireless channel 3. The narrow band transmission (reception) circuit 22 is controlled by the control unit 23 and transmits a signal to the wireless base station 1 via the narrow band wireless channel 4. If the narrow band wireless channel 4 can be formed in the downlink direction, narrow band transmission (reception)
It is assumed that the reception circuit 22 has a transmission / reception function. The timer 24 will be described later.

The information server 6 has a transmission / reception circuit 31, a storage medium 32, a control unit 33 and a timer 34 as shown in the schematic configuration of FIG. The transmission / reception circuit 31 transmits / receives signals to / from the communication network 5. The storage medium 32 is, for example, a hard disk, an optical disk, or another large-capacity storage device that stores moving image information such as a movie and other broadband information signals. The control unit 33 reads a broadband information signal from the storage medium 32 based on a control signal transmitted from the wireless base station 1 via the communication network 5 and the transmission / reception circuit 31, and sends it to the wireless base station 1 via the transmission / reception circuit 31. Take control. The timer 34 will be described later.

Next, the communication operation of the radio communication system according to this embodiment will be described. The communication operation in this embodiment basically has three modes according to the communication control procedure. The operation will be described below for each of these modes.

(First Communication Mode) FIG. 5 is a sequence diagram showing an outline of the first communication mode. The first communication mode uses a connection-type control procedure for establishing a connection (radio channel) between the wireless base station 1 and the wireless terminal 2 in advance as a communication control procedure prior to communication. First, when the user of the wireless terminal 2 wants to receive a desired wideband information signal from the information server 6, the wireless terminal 2 sends a reception start request to the wireless base station 1 via the narrowband wireless channel 4.

Upon receiving the reception start request from the wireless terminal 2, the wireless base station 1 sends a reception channel notification for designating the wideband wireless channel 3 used by the wireless terminal 2 to receive the wideband information signal to the narrowband wireless channel 4. Via the wireless terminal 2. As a result, the wireless base station 1 and the wireless terminal 2
A wideband radio channel 3 is formed between and.

Upon receiving the reception start request from the wireless terminal 2, the radio base station 1 sends the transmission start request to the information server 6 via the communication network 5. As a result, the broadband information signal is transmitted from the information server 6, relayed by the radio base station 1, and then transmitted to the radio terminal 2 via the broadband radio channel 3.

On the other hand, the user of the wireless terminal 2 determines that the information server 6
When it is desired to end the reception of the broadband information signal from the wireless terminal 2, the wireless terminal 2 sends a reception end request to the wireless base station 1 via the narrowband wireless channel 4. Upon receiving this reception end request, the radio base station 1 sends a reception channel release notification to the radio terminal 2 via the narrow band radio channel 4. As a result, the receiving channel of the wideband wireless channel 3 previously formed between the wireless base station 1 and the wireless terminal 2 is released. Further, the wireless base station 1 that has received the reception end request from the wireless terminal 2 ends the transmission of the broadband information signal to the wireless terminal 2.

Next, a more detailed procedure of the above-mentioned first communication mode will be described with reference to the flowchart shown in FIG. In the wireless terminal 2, when a reception start request signal is input from the input unit (not shown) to the control unit 23 (S101),
Narrow band transmission (reception) circuit 2 based on control from the control unit 23
1 transmits a reception start packet indicating a reception start request to the wireless base station 1 via the narrowband wireless channel 4 (S1).
02). In the wireless base station 1, when the reception start packet is received by the narrow band (sending) reception circuit 11 (S10).
3), the control unit 13 allocates a wideband wireless channel as a reception channel of the wireless terminal 3 (S104),
A broadband wireless channel assignment notification packet for notification of a reception channel is transmitted to the wireless terminal 2 via the narrowband wireless channel 4, and a transmission start request packet indicating a transmission start request is sent to the information server 6 via the communication network 5. It is transmitted (S105, S106). In the wireless terminal 2, when the wideband wireless channel assignment notification packet is received by the narrowband (sending) receiving circuit 21 (S107), the control unit 23 activates the wideband receiving circuit 21 (S108).

On the other hand, in the information server 6, when the transmission start packet is received by the transmission / reception circuit 31 (S10).
9), the broadband information signal is read from the storage medium 32 by the control unit 33 and transmitted from the transmission / reception circuit 31 to the wireless base station 1 via the communication network 5 (S110). The wireless base station 1 relays this broadband information signal as it is and transmits it to the wireless terminal 2 via the broadband wireless channel 3. In the wireless terminal 2, the transmitted broadband information signal is received by the broadband receiving circuit 21 (S111) and provided for display on, for example, an image monitor (not shown).

Next, in the wireless terminal 2, when a reception end request signal is input from the input unit (not shown) to the control unit 23 (S112), the narrow band transmission (reception) circuit 21 is controlled under the control of the control unit 23. Transmits a reception end packet indicating a reception end request to the wireless base station 1 via the narrowband wireless channel 4 (S113). In the wireless base station 1, when the reception end packet is received by the narrow band (sending) reception circuit 11 (S114), the reception end packet is transferred to the information server 6 via the communication network 5. When the information server 6 receives the transferred reception end packet (S11
5) At the same time as ending the transmission of the broadband information signal, a transmission end notification indicating that is transmitted to the wireless base station 1 via the communication network 5 (S116). In the wireless base station 1, when the control unit 13 receives the transmission end notification, the wideband wireless channel release packet is sent to the wireless terminal 2 via the narrowband wireless channel 4 (S117). In the wireless terminal 2, when the transmitted wideband wireless channel release packet is received by the narrowband transmission (reception) circuit 22 (S11).
8) Then, the control unit 23 stops the broadband receiving circuit 21 (S119).

As described above, in the first communication mode, since the control signals for the reception start request and the reception end request are transmitted from the wireless terminal 2 to the wireless base station 2 via the narrow band wireless channel 4, the amount of transmission information is small. From wireless terminal 2 to wireless base station 1
The frequency band of the wireless transmission path to can be saved.

The radio base station 1 controls the allocation / release of the wideband radio channel 3 from the radio base station 1 to the radio terminal 2 on the basis of the control signal of the reception start request sent from the radio terminal 2. In order to control the start / end of information transmission from the information server 6 to the wireless terminal 2, when the wireless terminal 2 receives the information from the information server 6, the wireless terminal 2 sends a control signal of a reception start request to the wireless base station. The control traffic is reduced because it is only necessary to send the signal once for one, and it is not necessary to send the control signal for the reception request again from the wireless terminal 2 after the wideband wireless channel 3 is formed. That is, the frequency band utilization efficiency is further improved by saving the frequency band of the wireless transmission path from the wireless terminal 2 to the wireless base station 1 and reducing the control traffic.

(Second Communication Mode) FIG. 7 is a sequence diagram showing an outline of the second communication mode. This second communication mode uses a connectionless control procedure as a communication control procedure in which a connection (wireless channel) is not established in advance between the wireless base station 1 and the wireless terminal 2 prior to communication, but a wireless channel is established each time communication is performed. It was what I had. In this second communication mode, the narrow band wireless channel 4 is transmitted from the wireless base station 1.
The wireless terminal 2 is notified of the channel status indicating the availability of the wideband wireless channel 3 via the. It should be noted that this channel state notification may include information regarding the availability of the information server 6. When the user of the wireless terminal 2 wants to receive a desired broadband information signal from the information server 6, it is confirmed from this channel state notification that the broadband wireless channel 3 is vacant and the information server 6 is vacant.
From the wireless terminal 2 to the wireless base station 1 via the narrow band wireless channel 4, a reception notification for requesting reception is performed. The radio base station 1 which has received the first notification of reception from the radio terminal 2
Sends a reception channel notification to the wireless terminal 2 via the narrowband wireless channel 4 for designating the wideband wireless channel 3 used for receiving the wideband information signal in the wireless terminal 2.
Thereby, the wideband wireless channel 3 is formed between the wireless base station 1 and the wireless terminal 2.

When the broadband wireless channel 3 is formed between the wireless base station 1 and the wireless terminal 2 in this way, the information server 6
From the wireless base station 1 to be relayed by the wireless base station 1 and then transmitted to the wireless terminal 2 via the broadband wireless channel 3. Then, the wireless terminal 2 transmits to the wireless base station 1 a reception notification indicating that the wideband information signal is being received at every predetermined transmission cycle T1 previously determined by the timer 14.

When the wireless terminal 2 finishes receiving the wideband information signal, the transmission cycle T after the previous notification of reception is performed.
Even if the time of 1 has elapsed, the reception notification is not transmitted.
The broken line in FIG. 7 indicates the timing of performing the notification during reception,
This is a case where the wireless terminal 2 ends the reception of the wideband information signal, and indicates that the notification during reception is not performed.

If the wireless base station 1 does not receive the next receiving notification within the communication continuation time limit T2 preset by the timer 14 after receiving the receiving notification, T
The transmission of the broadband information signal from the information server 6 to the wireless terminal 2 ends at the timing of the final time of 2.

Next, a more detailed procedure of the above-mentioned second communication mode will be described with reference to the flowcharts shown in FIGS. In the second communication mode, the broadband information notification packet for channel status notification described in FIG. 7 is transmitted by broadcasting from the information server 6 to the wireless terminal 2 via the communication network 3 and the wireless base station 1 at a constant cycle, for example. (S202). In the wireless terminal 2, when a reception start request signal is input from the input unit (not shown) to the control unit 23 (S201), the broadband information transmitted from the wireless base station 1 to the wireless terminal 2 via the narrowband wireless channel 4. The notification packet is received by the narrow band transmission (reception) circuit 22 (S203). In the wireless terminal 2, when the broadband information notification packet is received, the narrow band transmission (reception) circuit 22 sends the notification during reception described in FIG. 7 to the wireless base station 1 via the narrow band wireless channel 4. A resource reservation packet for transmission is transmitted (S204). In the wireless base station 1,
When the resource reservation packet is received by the narrow band (sending) reception circuit 12 (S205), the control unit 13 allocates the wide band wireless channel (S206), and the wide band wireless channel allocation notification packet is sent to the narrow band wireless channel 4 A resource reservation packet is transmitted to the information server 6 via the communication network 5 while being transmitted to the wireless terminal 2 via the communication network 5 (S20).
7, S208). In the wireless terminal 2, when the wideband wireless channel allocation notification packet is received by the narrowband (sending) receiving circuit 21 (S209), the control unit 23 activates the wideband receiving circuit 21 (S210).

On the other hand, in the information server 6, when the resource reservation packet is received by the transmission / reception circuit 31 (S21).
1), the broadband information signal is read from the storage medium 32 by the control unit 33 and transmitted from the transmission / reception circuit 31 to the wireless base station 1 via the communication network 5 (S212). The wireless base station 1 relays this broadband information signal as it is and transmits it to the wireless terminal 2 via the broadband wireless channel 3. In the wireless terminal 2, the transmitted broadband information signal is received by the broadband receiving circuit 21 (S213) and provided for display on, for example, an image monitor (not shown).

In the wireless terminal 2, when the broadband information signal is received, the control unit 23 activates the timer 24 (S214), and in the wireless base station 1, when the resource reservation packet is transmitted, the control unit 13 activates the timer 14. (S215) When the information server 6 transmits the broadband information signal, the control unit 33 activates the timer 34 (S216). Here, the time limit of the timer 24 is T
1 and the time limit of the timer 14 is T2. In this way, the processes after the timers 14, 24, 34 are activated are
It is shown in FIG.

That is, in the wireless terminal 2, when the timer 24 is started, it is checked whether or not the reception end request signal is input to the control unit 23 (S221), and the control is performed when the reception end request signal is input. The wideband receiving circuit 21 is stopped by the unit 23 (S222). When the reception end request signal is not input, the elapsed time of the timer 24 is the transmission cycle T
1 is checked (S223), and when T1 is reached, the resource reservation packet is controlled by the control unit 23 so that the resource reservation packet is transmitted from the narrowband transmission / reception circuit 22 via the narrowband wireless channel 4 to the wireless base station. 1 (S224), and the timer 24 is reset (S225).

In the radio base station 1, the timer 1
4 is activated, the presence / absence of a resource reservation packet transmitted from the wireless terminal 2 is checked (S231). If it is determined that the resource reservation packet is present, the resource reservation packet transmitted in S224 is narrow band (transmitted). ) The signal is received by the receiving circuit 12 (S232), and the control unit 13 resets the timer 14 (S233). When it is determined in S231 that there is no resource reservation packet, that is, there is no notification of reception from the wireless terminal 2, the time point when it is determined in S234 that the timer 14 has timed out, that is, the communication continuation time limit T2.
When the time elapses, the broadband wireless channel 3 is released by the control unit 14 (S235).

On the other hand, in the information server 6, the timer 3
4 is activated, the presence / absence of a resource reservation packet transmitted from the wireless base station 1 is checked (S241). If the resource reservation packet is received, the resource reservation packet transmitted in S232 is transmitted / received by the transmission / reception circuit 31. Received at (S24
2) Further, the timer 34 is reset by the control unit 33 (S243). When the resource reservation packet is not received in S241, when it is determined in S244 that the timer 34 has timed out, the control unit 34 ends the transmission / reception circuit 31 of the transmission of the broadband information signal (S245).

As described above, in the second communication mode, the wireless terminal 2 receives the information from the information server 6 and the broadband wireless channel 3
During reception via the narrowband wireless channel 4, the reception notification is periodically sent to the wireless base station 1, and the wireless base station 1 does not receive the notification during reception within a predetermined time. In this case, by ending the transmission of information from the information server 6 to the wireless terminal 2, it is possible to save the frequency band of the wireless transmission path from the wireless terminal 2 having a small amount of transmission information to the wireless base station 1.

Further, since it is not necessary to particularly send the control signal from the wireless terminal 2 to the wireless base station 1 at the end of reception, the switching of the receiving channel, that is, the change of the information server 6 of the information providing source is frequently performed. In this case, the number of times of transmitting the control signal is small, and the control traffic is reduced, so that the utilization efficiency of the frequency band is improved.

(Third Communication Mode) FIG. 10 is a sequence diagram showing the third communication mode. The third communication mode is a combination of the connection-type control procedure used in the first communication mode and the connectionless-type control procedure used in the second communication mode as the communication control procedure.

That is, the wireless base station 1 notifies the wireless terminal 2 via the narrowband wireless channel 4 of the channel status notification indicating the availability of the wideband wireless channel 3 and the availability of the information server 6. . When the user of the wireless terminal 2 wants to receive a desired broadband information signal from the information server 6, the broadband wireless channel 3 is sent from this channel state notification.
Is confirmed to be vacant and the information server 6 is vacant, and a reception notification for requesting reception from the wireless terminal 2 to the wireless base station 1 via the narrow band wireless channel 4 is performed. The radio base station 1 that has received the first reception notification from the radio terminal 2 issues a reception channel notification for designating the wideband radio channel 3 used for receiving the wideband information signal in the radio terminal 2 via the narrowband radio channel 4. To the wireless terminal 2. Thereby, the wideband wireless channel 3 is formed between the wireless base station 1 and the wireless terminal 2.

When the broadband wireless channel 3 is formed between the wireless base station 1 and the wireless terminal 2 in this way, the information server 6
From the wireless base station 1 to be relayed by the wireless base station 1 and then transmitted to the wireless terminal 2 via the broadband wireless channel 3. Then, the wireless base station 1 is receiving a broadband information signal within a fixed transmission cycle T1 or a communication continuation time limit T2 defined by the timer 14 from the time when the reception channel notification from the wireless terminal 2 is received. When the reception notification indicating that there is is not received from the wireless terminal 2, the transmission of the broadband information signal from the information server 6 to the wireless terminal 2 via the broadband wireless channel 3 is terminated.

Further, as in the case of the first communication mode described in FIG. 5, when the user of the wireless terminal 2 wants to finish receiving the wideband information signal from the information server 6, the narrowband wireless channel 4 is transmitted from the wireless terminal 2. A reception end request is transmitted to the wireless base station 1 via the. Upon receiving this reception end request, the radio base station 1 sends a reception channel release notification to the radio terminal 2 via the narrow band radio channel 4. As a result, the receiving channel of the wideband wireless channel 3 previously formed between the wireless base station 1 and the wireless terminal 2 is released. In addition, the wireless base station 1 that receives the reception end request from the wireless terminal 2
The transmission of the broadband information signal to the wireless terminal 2 is completed.

Next, a more detailed procedure of the above-mentioned third communication mode will be described using the flowcharts shown in FIGS. In the third communication mode, the broadband information notification packet for channel state notification described in FIG. 10 is transmitted by broadcasting from the information server 6 to the wireless terminal 2 via the communication network 3 and the wireless base station 1 at a constant cycle, for example. (S302). In the wireless terminal 2, when a reception start request signal is input from the input unit (not shown) to the control unit 23 (S301), the broadband information transmitted from the wireless base station 1 to the wireless terminal 2 via the narrowband wireless channel 4. The notification packet is received by the narrow band transmission (reception) circuit 22 (S303). In the wireless terminal 2, when the broadband information notification packet is received, the narrowband transmission (reception) circuit 22 notifies the wireless base station 1 via the narrowband wireless channel 4 of the notification of reception described in FIG. The resource reservation packet is transmitted (S304). In the wireless base station 1, when the resource reservation packet is received by the narrow band (sending) receiving circuit 12 (S305), the control unit 13 allocates the wide band wireless channel (S306), and the wide band wireless channel allocation notification is issued. The packet is transmitted to the wireless terminal 2 via the narrow band wireless channel 4, and the resource reservation packet is transmitted to the information server 6 via the communication network 5 (S307, S308). In the wireless terminal 2, when the wideband wireless channel assignment notification packet is received by the narrowband (sending) receiving circuit 21 (S309), the control unit 23 activates the wideband receiving circuit 21 (S310).

On the other hand, in the information server 6, when the resource reservation packet is received by the transmission / reception circuit 31 (S31).
1), the broadband information signal is read from the storage medium 32 by the control unit 33 and transmitted from the transmission / reception circuit 31 to the wireless base station 1 via the communication network 5 (S312). The wireless base station 1 relays this broadband information signal as it is and transmits it to the wireless terminal 2 via the broadband wireless channel 3. In the wireless terminal 2, the transmitted broadband information signal is received by the broadband receiving circuit 21 (S313) and provided for display on, for example, an image monitor (not shown).

In the wireless terminal 2, when the broadband information signal is received, the control unit 23 activates the timer 24 (S
314), in the radio base station 1, when the resource reservation packet is transmitted, the control unit 13 activates the timer 14 (S315). Here, the time limit time of the timer 24 is T3,
The time limit time of the timer 14 is T2. Thus timer 1
The processing after the activation of Nos. 4 and 24 is shown in FIG.

That is, in the wireless terminal 2, when the timer 24 is started, it is checked whether or not the reception end request signal is input to the control unit 23 (S321), and the control is performed when the reception end request signal is input. The wideband receiving circuit 21 is stopped by the unit 23 (S322). When the reception end request signal is not input, the elapsed time of the timer 24 is the transmission cycle T
3 is checked (S323), and when T3 is reached, the resource reservation packet is controlled by the control unit 23 so that the resource reservation packet is transmitted from the narrowband transmission / reception circuit 22 via the narrowband wireless channel 4 to the wireless base station. 1 (S324).

On the other hand, in the radio base station 1, the timer 1
4 is activated, the presence / absence of a resource reservation packet transmitted from the wireless terminal 2 is checked (S325). If it is determined that there is a resource reservation packet, the resource reservation packet transmitted in S324 is in a narrow band (sending). The signal is received by the receiving circuit 12 (S326), and the timer 14 is stopped by the control unit 13 (S327). When it is determined in S325 that there is no resource reservation packet, that is, there is no notification of reception from the wireless terminal 2, at the time when it is determined that the timer 14 has timed out in S328, that is, when the communication continuation time limit T2 has elapsed. The control unit 14 releases the broadband wireless channel 3 (S329).

Next, after the resource reservation packet is transmitted in S324 in the wireless terminal 2, a reception end request signal is input to the control unit 23 from an input unit (not shown) (S33).
0), under the control of the control unit 23, the reception end packet, which is a reception end request, is transmitted from the narrow band transmission (reception) circuit 21 to the wireless base station 1 via the narrow band wireless channel 4 (S331). In the wireless base station 1, when the reception end packet is received by the narrow band (sending) reception circuit 11 (S33).
2) Transfer the reception end packet to the information server 6 via the communication network 5. When the information server 6 receives the transferred reception end packet (S333), the transmission of the broadband information signal is ended, and a transmission end notification indicating that is transmitted to the wireless base station 1 via the communication network 5. Do (S
334). In the wireless base station 1, when the control unit 13 receives the transmission end notification, the wideband wireless channel release packet is sent to the wireless terminal 2 via the narrowband wireless channel 4 (S335). In the wireless terminal 2, when the transmitted wideband wireless channel release packet is received by the narrowband transmission (reception) circuit 22 (S336), the control unit 23 stops the wideband reception circuit 21 (S33).
7).

As described above, in the third communication mode, the wireless terminal 2 sends the information from the information server 6 to the broadband wireless channel 3
If the information is being received within a predetermined time from the start of reception via the wireless base station 1, the wireless base station 1 is notified of the reception via the narrow band wireless channel 4, and the wireless base station 1
Ends the transmission of information from the information server 6 to the wireless terminal 2 when the receiving notification is not received within a predetermined time, and when the receiving notification is received within the predetermined time,
By continuing the transmission of information from the information server 6 to the wireless terminal 2 until the control signal of the reception end request is received from the wireless terminal 2 via the narrowband wireless channel 4, the wireless terminal 2 with a small amount of transmission information wirelessly transmits. The frequency band of the wireless transmission path to the base station 1 can be saved.

Further, for example, in the VOD service, T
In the case where the same channel is continuously used for a relatively short time after switching the channel, as in the case of searching the V screen, the control signal of the reception end request is transmitted from the wireless terminal 2 every time the channel is switched. Since there is no need, control traffic is reduced and the frequency band utilization efficiency is improved.

Next, a communication method according to another embodiment of the present invention will be described with reference to FIGS. 13 and 14. In this embodiment,
In the wireless communication system as described in the previous embodiment, the type of communication service (application service) to be provided is identified, and the control procedure for communication between the wireless base station 1 and the wireless terminal 2 is selected based on that. It was done like this.

FIG. 13 is a flow chart showing the outline of the selection procedure. First, in the configuration of FIG.
From the wireless base station 1 to the wireless base station 1 through the narrowband wireless channel 4 to transmit an identification signal for identifying the desired type of communication service. FIG. 14 shows an example of a format of a data packet including such an identification signal. A service identification number is added following a synchronization bit and a protocol identification number, followed by a transmission rate, an average delay time, Declaration parameters such as delay distribution are placed, and there is a final end flag.

The radio base station 1 identifies the type of application service from the service identification number (S4).
01). In the example of FIG. 13, the types of application services are roughly classified into three types: a bidirectional stream type application A1, an asymmetric stream type application A2, and a unidirectional data type application A3. Application A1 is used for telephone and video conference
The application A2 is for CATV, VOD and spot broadcasting, and the application A3 is for file transfer and mail.

Here, when the application service is the bidirectional stream type application A1 and CATV or VOD in the asymmetric stream type application A2, the connection type control procedure is selected (S402), and the asymmetric stream type is selected. In the case of spot broadcasting in the application A2 and the one-way data system application A3, the connectionless control procedure is selected (S403). The connection type control procedure is, for example, the control procedure used in the first communication mode described above, and the connectionless control procedure is the control procedure used in the second communication mode.

In this way, by selecting the communication control procedure according to the type of communication service to be provided by the wireless terminal 2, for example, by forming vertically symmetrical wireless channels in the applications A2 and A3, the wireless channel is formed. It is possible to prevent an increase in control traffic due to wasteful use of resources or useless communication control for the service to be provided, and it is possible to further improve the utilization efficiency of frequency resources.

[0063]

As described above, according to the present invention, a radio base station, a radio terminal and an information server are provided, and a signal is transmitted from the radio base station to the radio terminal through at least a wideband radio channel, and the radio is transmitted. In a wireless communication system in which signals are transmitted from a terminal to a wireless base station via a narrowband wireless channel, it is possible to improve utilization efficiency of the wideband wireless channel and reduce control traffic, thereby effectively utilizing frequency resources. be able to.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing an internal configuration of the radio base station in FIG.

FIG. 3 is a block diagram showing an internal configuration of the wireless terminal in FIG.

FIG. 4 is a block diagram showing the internal configuration of the information server in FIG.

FIG. 5 is a sequence diagram showing an outline of a first communication mode.

FIG. 6 is a flowchart showing a detailed procedure of a first communication mode.

FIG. 7 is a sequence diagram showing an outline of a second communication mode.

FIG. 8 is a flowchart showing a detailed procedure of a second communication mode.

FIG. 9 is a flowchart showing a detailed procedure of a second communication mode.

FIG. 10 is a sequence diagram showing an outline of a third communication mode.

FIG. 11 is a flowchart showing a detailed procedure of a third communication mode.

FIG. 12 is a flowchart showing a detailed procedure of a third communication mode.

FIG. 13 is a flowchart showing a procedure for selecting a communication control procedure according to the type of application service.

FIG. 14 is a diagram showing an example of a data format to which an identification number for identifying the type of application service is added.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wireless base station 2 ... Wireless terminal 3 ... Wideband wireless channel 4 ... Narrowband wireless channel 5 ... Communication network 6 ... Information server 11 ... Wideband receiving circuit 12 ... Narrowband (sending) receiving circuit 13 ... Control unit 14 ... Timer 21 Wide band transmission circuit 22 Narrow band transmission (reception) circuit 23 Control unit 24 Timer 31 Transmitting / receiving circuit 32 Storage medium 33 Control unit 34 Timer

Claims (5)

[Claims] 1. A wireless base station, a wireless terminal, and an information server for transmitting information to the wireless terminal via the wireless base station, the wireless base station to the wireless terminal via at least a wideband wireless channel. A communication method in a wireless communication system in which a signal is transmitted and a signal is transmitted from a wireless terminal to a wireless base station via a narrowband wireless channel, and reception is started from the wireless terminal to the wireless base station via a narrowband wireless channel. Sends control signals for request and reception end request,
A communication method in a wireless communication system, wherein a wireless base station controls allocation / release of a wideband wireless channel and control start / end of information transmission from an information server to a wireless terminal based on the control signal. 2. A wireless base station, a wireless terminal, and an information server for transmitting information to the wireless terminal via the wireless base station, the wireless base station to the wireless terminal via at least a wideband wireless channel. A communication method in a wireless communication system that transmits a signal and transmits a signal from a wireless terminal to a wireless base station via a narrowband wireless channel, in which the wireless terminal receives information from an information server via a wideband wireless channel. During the reception, the radio base station periodically sends a reception notification indicating that the information is being received to the radio base station via the narrow band radio channel, and the radio base station transmits the reception notification within a predetermined time. A communication method in a wireless communication system, characterized in that the transmission of information from the information server to the wireless terminal is terminated when the information is not received. 3. A wireless base station, a wireless terminal, and an information server for transmitting information to the wireless terminal via the wireless base station, the wireless base station to the wireless terminal via at least a wideband wireless channel. A communication method in a wireless communication system that transmits a signal and transmits a signal from a wireless terminal to a wireless base station via a narrowband wireless channel, in which the wireless terminal receives information from an information server via a wideband wireless channel. If the information is being received within a predetermined time from the start of, the reception notification indicating that the information is being received is sent to the wireless base station via the narrowband wireless channel, and the wireless If the base station does not receive the reception notification within the predetermined time, the base station ends the transmission of information from the information server to the wireless terminal, and receives the reception notification within the predetermined time. In this case, the communication method in the wireless communication system is characterized in that transmission of information from the information server to the wireless terminal is continued until the control signal of the reception end request is received from the wireless terminal via the narrow band wireless channel. 4. A wireless base station, a wireless terminal, and an information server for transmitting information to the wireless terminal via the wireless base station, the wireless base station to the wireless terminal via at least a wideband wireless channel. A communication method in a wireless communication system for transmitting a signal and transmitting a signal from a wireless terminal to a wireless base station via a narrowband wireless channel. A communication method in a wireless communication system, characterized in that an identification signal for identifying the type of communication service to be transmitted is transmitted, and the wireless base station selects a control procedure for communication between the wireless base station and the wireless terminal based on the identification signal. . 5. A wireless base station, a wireless terminal, and an information server for transmitting information to the wireless terminal via the wireless base station, the wireless base station to the wireless terminal via at least a wideband wireless channel. A communication method in a wireless communication system for transmitting a signal and transmitting a signal from a wireless terminal to a wireless base station via a narrowband wireless channel. The identification signal for identifying the type of communication service to be transmitted is transmitted, and the radio base station selects a connection control procedure or a connectionless control procedure for communication between the radio base station and the radio terminal based on the identification signal. A communication method in a wireless communication system characterized by selecting.