KR100846025B1 - Mobile packet communication system - Google Patents

Abstract

When the radio base station 2 performs real-time IP data communication, an uplink radio resource for transmitting the transmission data in synchronization with the codec period of the mobile communication terminal 1 and intensively based on the transmission data basic information. Is assigned. This information is notified to the mobile communication terminal 1 as an uplink transmission schedule. The mobile communication terminal 1 performs transmission control of a radio frame based on this uplink transmission schedule. As a result, when the mobile communication terminal 1 transmits the IP data upward, transmission to the wireless transmission path is performed in accordance with the codec timing of the mobile communication terminal 1, and the delay that occurs in relation to the wireless access is reduced. It becomes small and the transmission delay between transmission and reception terminals is reduced.

Description

Mobile packet communication system {MOBILE PACKET COMMUNICATION SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile packet communication system using a radio access method such as CDMA, OFDMA, and the like, and more particularly, to scheduling that improves the followability of transmission processing for data requiring real time.

At present, a study is underway for the development of the Internet Protocol (IP) of mobile communication systems. According to this, for example, IP packets are also generated for real-time data that requires real-time, such as voice and moving images, and the transmission delay between two terminals to transmit and receive depending on the routing path may be a problem. It is expected. It is also desirable to be able to reduce as much as possible the delay associated with radio access.

On the other hand, conventionally, a method of performing dynamic band allocation (scheduling) by mixing data having real-time characteristics and data having burst characteristics in a time division radio access method has been proposed. The method gives priority to the CBR / VBR / ABR class from the scheduled transmission completion time (sending time plus the cycle time) and the amount of received data to be received until the transmission completion time, and the priority is high. Band allocation is performed by giving priority to transmission data (see Patent Document 1 below).

(Patent Document 1) Japanese Unexamined Patent Publication No. 2001-223716

However, such a conventional scheduling method calculates a priority from the time and the amount of received data based on the cycle time of each service, and does not preferentially process the service with a severe demand for delay. As a result, delays and fluctuations in cycle time may occur. In addition, in the above-described scheduling method, since the scheduled transmission completion time is determined based on the reference time of the parent station, the time at which the data transmission request is generated and the scheduled transmission completion time are not synchronized, which causes the delay. Also occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The present invention is to transmit real-time IP data requiring real-time to the wireless transmission path in accordance with the codec timing of the mobile communication terminal in uplink transmission from the mobile communication terminal side. It is an object of the present invention to obtain a mobile packet communication system that can minimize delays associated with radio access and can reduce transmission delays between transmission and reception terminals.

In the mobile packet communication system of the present invention, when performing real-time IP data communication, an uplink radio resource is synchronized so as to transmit transmission data in synchronization with a codec period of a mobile communication terminal based on transmission data basic information. The mobile communication terminal has a real-time system because it has a radio base station for assigning and notifying the mobile communication terminal of the allocation result as an uplink transmission schedule, and a mobile communication terminal for performing radio frame transmission control based on the uplink transmission schedule. When transmitting IP data upward, transmission to the wireless transmission path is performed in accordance with the codec timing of the mobile communication terminal. Accordingly, delays caused by radio access operations can be reduced, and transmission delays between transmission and reception terminals can be reduced.

The transmission data basic information includes codec start time information determined by the mobile communication terminal, and the uplink transmission schedule created by the wireless base station also includes a codec start timing of the mobile communication terminal. That is, the mobile communication terminal determines the codec start reference time by itself, transmits transmission data basic information including the codec start time information including the reference time to the wireless base station, and when the wireless base station schedules, the codec start time. The information is also taken into account to generate an uplink transmission schedule, and the mobile communication terminal performs radio frame transmission control based on the uplink transmission schedule. In this way, the start time of the session can be stabilized by the mobile communication terminal leading the decision of the codec start time.

On the other hand, there is also a method in which the mobile communication terminal determines the codec start timing based on the uplink transmission schedule transmitted from the wireless base station. That is, the information about the codec start time is not included in the transmission data basic information transmitted from the mobile communication terminal to the wireless base station, and the mobile communication terminal determines the codec start timing based on the uplink transmission schedule created by the wireless base station. As such, by determining the codec start time of the mobile communication terminal under the control of the radio base station, the delay related to the radio access can be further reduced.

In addition, communication parameter information based on the service contents of the transmission data is added to the transmission data basic information by the radio base station control apparatus. Therefore, different data types are added according to the service contents, and when the uplink transmission schedule is created, the codec start time can be determined more accurately, and a highly reliable transmission operation can be performed.

1 is a system diagram showing the configuration of a mobile packet communication system according to the present invention;

2 is a functional block diagram of a part related to uplink transmission schedule creation of a mobile communication terminal;

3 is a functional block diagram of a part about creating an uplink transmission schedule of a wireless base station;

4 is a schematic diagram illustrating a state in which an uplink transmission schedule is determined based on codec start time information;

5 is a graph showing a state of radio resource allocation according to the first embodiment of the present invention;

6 is a flowchart showing the operation of radio resource allocation according to the first embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating a state in which an uplink transmission schedule is determined by a codec start time determined by an inversion indicative of a feature of a mobile packet communication system according to a second embodiment of the present invention; FIG.

8 is an explanatory diagram for explaining a state of an uplink transmission schedule during handover;

9 is a graph showing information on radio resource allocation for explaining characteristics of the mobile packet communication system according to the third embodiment of the present invention;

10 is a graph showing a state of dynamically changing radio resource allocation, which is a characteristic of a mobile packet communication system according to a fourth embodiment of the present invention;

11 is a flowchart showing an operation in the case of a radio resource allocation failure, which shows the characteristics of the mobile packet communication system according to the fifth embodiment of the present invention;

12 is a graph showing a state of reallocation from a radio resource under provisional allocation to a radio resource originally scheduled.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of the mobile packet communication system which concerns on this invention is described in detail based on drawing. In addition, this invention is not limited by this Example.

(Example 1)

1 is a system diagram showing the configuration of a mobile packet communication system according to the present invention. In Fig. 1, the mobile communication terminal 1, the radio base station 2, and the radio base station control device 3 together with the core network 4 constitute a mobile communication network 5. The mobile communication network 5 is connected to the external IP network 6, and the IP terminal 7 is connected to the external IP network 6. In addition, in this embodiment, a code division multiple access (CDMA) is assumed as a radio access method. However, the present invention is not limited thereto, and application to orthogonal frequency division multiple access (OFDMA) or the like can be similarly considered.

2 is a functional block diagram of a portion related to uplink transmission schedule creation of the mobile communication terminal 1. 2, the mobile communication terminal 1 includes an encoder 11, a transmission signal generator 12, a radio signal transmitter 13, a reception signal analyzer 14, a radio signal receiver 15 and a controller. It consists of (16). In the mobile communication terminal 1, the transmission data encoded by the encoding unit 11 is loaded into a predetermined radio channel control signal by the transmission signal generation unit 12 to become a transmission signal, and the radio signal transmission unit 13 Is sent from. On the other hand, the received signal received by the wireless signal receiver 15 is analyzed by the received signal analyzer 14. The control unit 16 manages these operations.

3 is a functional block diagram of a portion related to the uplink transmission schedule creation of the radio base station 2. As shown in FIG. In FIG. 3, the radio base station 2 includes a control signal analyzer 21, an uplink radio resource allocator 22, a mobile device control signal generator 23, and a radio signal transmitter 24. If the signal input from the radio base station controller 3 is a radio channel setting request, it is passed to the uplink radio resource allocator 22, where the uplink radio resource allocation, that is, scheduling of the uplink transmission schedule. This is done. The uplink transmission schedule obtained as a result is transmitted to the mobile unit control signal generation unit 23, where it is carried in a predetermined radio channel control signal to be a transmission signal, and is transmitted from the radio signal transmission unit 24 to the mobile communication terminal 1. do.

Next, the operation will be described. A case where a session of real-time IP data communication is performed between the mobile communication terminal 1 and the IP terminal 7 will be described as an example.

(1) Generation of transmission data basic information in the mobile communication terminal

The operation until the uplink transmission data basic information is generated in the mobile communication terminal 1 and notified to the radio base station control device 3 will be described.

For example, it is assumed that a session of real-time IP data communication is started by triggering an operation input of an operator. When the session is started, first, the control unit 16 (see Fig. 2) recognizes the start of the radio channel establishment procedure of the real-time IP data communication, and instructs the encoding unit 11 to request a codec start timing determination request. . The encoding unit 11 which has received an instruction of the codec start timing determination request determines the time that is the reference for the codec start, and sends the time information to the control unit 16. The control unit 16 calculates an uplink transmission start reference time by adding a predetermined processing time to the codec start reference time, and sends it to the transmission signal generation unit 12. Here, the predetermined processing time is processing time from the codec completion timing which each mobile communication terminal 1 holds as unique information to the radio frame transmission.

The uplink transmission start reference time sent to the transmission signal generation unit 12 is carried in the radio channel control signal as part of the quality of service (QoS) information, transmitted from the radio signal transmission unit 13, and the radio base station 2 is transmitted. Via the radio base station control device 3 via.

The method for generating uplink transmission data basic information in the mobile communication terminal 1 and notifying the radio base station controller 3 may be as follows. That is, the control unit 16 recognizes the start of the radio channel establishment procedure and makes a request for the codec start timing determination to the encoder 11. The encoder 11 receiving the codec start timing determination request performs the codec on the dummy data until the radio channel for real-time IP data is established, and sends the generated IP packet to the transmission signal generation unit 12. The transmission signal generation unit 12 recognizes the time when the IP packet was received as the codec start reference time, adds a predetermined processing time to the codec start reference time, calculates the uplink transmission start reference time, and discards the dummy data. do. The transmission signal generator 12 carries the uplink transmission reference time as part of the QoS information in the radio channel control signal, is transmitted from the radio signal transmitter 13, and is transmitted to the radio base station control device 3 via the radio base station 2. Is delivered to.

(2) Wireless channel setting request from wireless base station control device 3 to wireless base station 2

The radio base station control device 3 that has received the transmission reference time information from the mobile communication terminal 1, together with the information, transmits the radio of the mobile communication terminal 1 per codec cycle time, communication type, and codec cycle time for the session. Information of the maximum transmission data amount in the direction of the base station 2 (upward) is written as part of the QoS information, and a radio channel setting request including the QoS information is transmitted to the radio base station 2.

(3) Uplink radio resource allocation in the radio base station 2

The following describes a method of allocating an uplink radio resource of the radio base station 2 and notifying the mobile communication terminal 1 of an uplink schedule when the radio base station controller 3 receives a request for setting a radio channel. .

The control signal analyzer 21 (see Fig. 3), which receives the radio channel setting request from the radio base station controller 3, sends the QoS information to the uplink radio resource allocator 22. On the basis of these information, the uplink radio resource allocating unit 22 transmits a radio frame in synchronization with the codec timing of the mobile communication terminal 1 and concentrates if the communication type is included in the real-time IP data communication. Create an uplink transmission schedule.

4 is a schematic diagram illustrating a state in which an uplink transmission schedule is determined based on codec start time information. As shown in FIG. 4, the uplink radio resource allocating unit 22 allocates radio resources so as to synchronize the codec timing of the mobile communication terminal 1 and concentrate and transmit radio frames based on QoS information. do. That is, the radio resources are allocated continuously at every codec interval until the call is released. The uplink transmission schedule (including the transmission permission time, the spreading factor, etc.) that is the result of this assignment is transmitted from the mobile unit control signal generation unit 23 and passes through the radio signal transmission unit 24 to the mobile communication terminal 1. Is delivered.

Here, the radio resource allocation operation of the uplink radio resource allocation unit 22 will be described in detail.

5 is a graph showing the state of radio resource allocation. The vertical axis represents the number of allocated radio resources, and the horizontal axis represents time. 6 is a flowchart illustrating the operation of radio resource allocation.

As shown in FIG. 5, the radio base station 2 manages the allocation of radio resources for each transmission unit time of the uplink transmission schedule. When a new radio resource allocation is requested, the radio base station 2 first assigns the uplink transmission reference time to the unit transmission time. Correction in accordance with the step (step 101 of Fig. 6). However, the condition of "upstream transmission reference time before correction" <"upstream transmission reference time after correction" is applied. When the uplink transmission reference time after correction is smaller than the time that the radio base station 2 can allocate to the current uplink radio resource, that is, when the above-described inequality is satisfied (that is, "uplink transmission reference time after correction" <"assignment Available time ”), the operation of adding the codec cycle time is repeated several times to satisfy the condition (steps 102 and 103 in FIG. 6).

When the uplink transmission reference time after recalibration and the predetermined codec period timing are available, a radio resource capable of transmitting the maximum amount of uplink transmission data per cycle time can be secured (by the sum of the interference powers in the wireless base station 2). In determining the upper limit of the resource, a corresponding spreading factor is allocated as the success of the radio resource allocation (steps 104, 105, and 106 of FIG. 6).

On the other hand, when radio resources cannot be secured (No in steps 104 and 105 in FIG. 6), the radio resource allocation is rejected as a failure in radio resource allocation (step 107 in FIG. 6).

(4) Uplink transmission control in the mobile communication terminal 1

Next, the uplink transmission control in the mobile communication terminal 1 which accepted the uplink transmission schedule is demonstrated. The mobile communication terminal 1 sends the uplink transmission schedule acquired through the radio signal receiver 15 (see FIG. 2) and the reception signal analyzer 14 to the control unit 16 and, according to the received transmission schedule, the radio signal. Transmission control of the transmitter 13 is performed.

When the mobile communication terminal 1 hands over to another cell and sector, the radio base station 2 of the cell and sector of the moving destination moves upward of the mobile communication terminal 1 in the same order as when the radio channel is established. Determine the transmission schedule.

As described above, in the mobile packet communication system of the present embodiment, when performing real-time IP data communication, the transmission data is concentrated and synchronized with the codec period of the mobile communication terminal 1 based on the transmission data basic information. A radio base station (2) is allocated for uplink radio transmission, and the radio base station (2) notifying the mobile communication terminal (1) of this result as an uplink transmission schedule, and a mobile communication for performing radio frame transmission control based on the uplink transmission schedule. Since it has the terminal 1, when the mobile communication terminal 1 transmits real-time system IP data upward, it transmits to a wireless transmission path according to the codec timing of the mobile communication terminal 1. As shown in FIG. Accordingly, delays associated with radio access can be reduced, and transmission delays between transmission and reception terminals can be reduced.

In addition, the transmission data basic information created by the mobile communication terminal 1 includes the codec start time information determined by the mobile communication terminal 1, and the uplink transmission schedule generated by the wireless base station 2 includes the mobile communication terminal ( The codec start timing of 1) is also included. That is, the mobile communication terminal 1 determines the codec start reference time, transmits the transmission data basic information including the reference time to the radio base station 2 via the radio base station controller 3, and the radio base station 2 Also generates the uplink transmission schedule in consideration of the codec start time information, and the mobile communication terminal 1 performs the transmission control of the radio frame based on the resulting uplink transmission schedule. Thus, by determining the codec start time under the initiative of the mobile communication terminal 1, stable session start timing can be obtained.

In addition, communication parameter information corresponding to the service contents of the transmission data is added by the radio base station control device 3 to the transmission data basic information transmitted to the radio base station 2. Therefore, a more accurate codec start time can be achieved and a highly reliable transmission operation can be performed.

(Example 2)

Fig. 7 is a schematic diagram illustrating a state in which an uplink transmission schedule is determined by a codec start time obtained by inversion, which is characteristic of the mobile packet communication system according to the second embodiment of the present invention.

In the present embodiment, contrary to the first embodiment, the mobile communication terminal 1 determines the codec start timing based on the uplink transmission schedule created by the radio base station 2.

The uplink transmission scheduling process of the mobile communication terminal 1 in association with the radio base station 2 will be described according to the flow of the process.

(1) Wireless channel setting request from wireless base station control device 3 to wireless base station 2

For example, when initiating a session of real-time IP data communication between the mobile communication terminal 1 and the IP terminal 7, the wireless base station control device 3 performs the codec cycle time, communication type, and codec cycle time for the session. Information of the maximum transmission data amount in the direction of the wireless base station 2 (upward) of the mobile communication terminal 1 is written as part of the QoS information, and a radio channel setting request including the QoS information is transmitted to the wireless base station 2.

(2) Uplink radio resource allocation in the radio base station 2

The control signal analyzer 21 (see Fig. 3), which receives the radio channel setting request from the radio base station controller 3, sends the QoS information to the uplink radio resource allocator 22. In the uplink radio resource allocating unit 22, if the communication type is included in the real-time IP data communication based on the QoS information, as shown in Fig. 7, the radio resource is codec so as to concentrate and transmit the radio frame. Each call is allocated until the call is released (the radio base station 2 determines the transmission reference time that can be assigned by the period). The uplink transmission schedule that is the result of this assignment is transmitted to the mobile communication terminal 1 via the mobile unit control signal generator 23 and the radio signal transmitter 24.

(3) Uplink transmission control in the mobile communication terminal 1

The uplink transmission control in the mobile communication terminal 1 which accepted the uplink transmission schedule is demonstrated. The mobile communication terminal 1 transmits the uplink transmission schedule acquired by the radio signal receiving unit 15 and the reception signal analyzing unit 14 to the control unit 16. According to the uplink transmission schedule, the control unit 16 transmits the radio signal to the encoder 11 in consideration of the processing time from the codec completion timing to the radio frame transmission, as shown in FIG. 7. After the shift control of the codec start timing is performed so as to minimize the delay up to, the transmission control of the radio signal transmitter 13 is performed.

8 is an explanatory diagram for explaining a state of an uplink transmission schedule during handover. When the mobile communication terminal 1 hands over to another cell and sector, the radio base station 2 of the cell and sector of the moving destination is transmitted upward by the mobile communication terminal 1 in the same order as when the radio channel is established. Determine the schedule. At this time, as shown in Fig. 8, since the codec start timing is changed, the data being encoded is discarded.

As described above, in the mobile packet communication system of the present embodiment, the mobile communication terminal 1 determines the codec start timing based on the uplink transmission schedule. That is, the transmission data basic information created by the mobile communication terminal 1 does not include the information on the codec start, and the mobile communication terminal 1 starts the codec based on the uplink transmission schedule created by the wireless base station 2. Determine the timing. As such, by determining the codec start time by the initiative of the radio base station 2, the delay related to radio access can be further reduced.

At the time of handover, the uplink transmission schedule is created by the radio base station 2 of the cell and sector of the moving destination in the same order. Therefore, the delay associated with radio access can also be reduced for uplink real-time system IP data transmission during handover.

(Example 3)

9 is a graph showing radio resource allocation information for explaining the characteristics of the mobile packet communication system according to the third embodiment of the present invention. This embodiment is characterized in operation when a retransmission request is received. When the mobile communication terminal 1 receives a retransmission request from the radio base station controller 3 or the radio base station 2, the retransmission request is transmitted to the radio signal receiver 15 (see FIG. 2) and the received signal analyzer ( Via 14), it is transmitted to the control unit 16.

As shown in Fig. 9, the control unit 16 uses the radio resources of the best-effort system data rather than the real-time system data, and allocates the radio resource allocation method for the best effort (real-time system data). The transmission signal generator 12 and the radio signal transmitter 13 are controlled so as to transmit retransmission data with respect to the radio resource that is not used, for example, in a method of determining the transmission timing by a random variable.

As described above, in the mobile packet communication system of the present embodiment, when performing normal real-time IP data communication, the mobile communication terminal 1 transmits using the radio resource allocated for each codec period, and when retransmitting, The transmission is performed using the radio resource allocated for the effort. According to the radio resource allocation method for the best effort, delays can be prevented from being periodically transmitted due to the effect of packet retransmission.

(Example 4)

Fig. 10 is a graph showing the state of dynamically changing radio resource allocation, which is characteristic of the mobile packet communication system according to the fourth embodiment of the present invention. The vertical axis represents the number of allocated radio resources, and the horizontal axis represents time.

In the first embodiment described above, when the radio base station 2 determines that the uplink radio quality from the mobile communication terminal 1 is degraded, as shown in FIG. 10 (a), an uplink radio resource allocation unit is shown. In step 22, the radio resource allocation that concentrates on transmitting the radio frame is stopped. As shown in Fig. 10 (b), the mobile communication terminal 1 informs the mobile communication terminal 1 of the uplink transmission schedule as a result of the spreading (averaging) in the time direction and reassigning the radio resources to transmit radio transmission frames.

On the other hand, when the radio quality is good, as shown in Fig. 10A, the uplink radio resource allocating unit 22 reassigns so as to concentrate and transmit the radio frame as in the beginning. Then, the information is notified to the mobile communication terminal 1. The mobile communication terminal 1 performs the transmission control of the radio signal similarly to the first embodiment in accordance with the information.

As described above, in the mobile packet communication system of the present embodiment, the radio base station 2 reschedules an uplink transmission schedule to a time-averaged schedule at the time of radio quality deterioration. Therefore, packet loss with respect to the burst error at the time of radio quality deterioration can be reduced.

(Example 5)

Fig. 11 is a flowchart showing operation at the time of failure of radio resource allocation, which shows the characteristics of the mobile packet communication system according to the fifth embodiment of the present invention.

This embodiment is characterized by an operation upon failure of radio resource allocation. In the present embodiment, in the above-described embodiments 1 and 4, the uplink radio resource allocating unit 22 does not reject the radio resource allocation upon failure of radio resource allocation (step 107 in FIG. 6). The process is performed.

First, the coefficient N is initialized to 1 (step 111 in FIG. 11), and a radio resource capable of transmitting an uplink transmission reference time + Nx unit transmission time or an uplink maximum transmission data amount per cycle time for each codec period is secured. If possible, the corresponding spreading factor is allocated as the radio resource provisional allocation (steps 112, 113, and 114 in FIG. 11).

On the other hand, when the radio resource cannot be secured, in the case of Nx unit transmission time <codec period, it is set to N = N + 1 and returns to step 112 (step 116 in FIG. 11), otherwise, the radio resource. The assignment is rejected (step 117 in FIG. 11).

As described above, in the present embodiment, when it is determined that the radio resource with the minimum occurrence of delay related to radio access cannot be allocated, the radio resource with the minimum delay is allocated among the radio resources that can be allocated at the codec period interval. The information is notified to the mobile communication terminal 1.

In addition, when the radio resources allocated by the above call and being used by other calls are released, the uplink radio resource allocating unit 22 is initially scheduled from the radio resources under provisional allocation as shown in FIG. The allocation is changed to the radio resource that was, and the information is notified to the mobile communication terminal 1.

In accordance with the updated uplink transmission schedule, the mobile communication terminal 1 performs transmission control of a radio signal similarly to the first embodiment.

In this manner, in the mobile packet communication system of the present embodiment, it is possible to reduce the probability of reception failure of a call while minimizing the occurrence of delay related to radio access.

As described above in the first to fifth embodiments, in the mobile packet communication system of the present invention, when the wireless base station 2 performs real-time IP data communication, the mobile communication terminal 1 is based on the transmission data basic information. The uplink radio resource is allocated so that the transmission data is synchronized with each other in synchronization with the codec period of s). This information is notified to the mobile communication terminal 1 as an uplink transmission schedule. The mobile communication terminal 1 performs transmission control of a radio frame based on this uplink transmission schedule. As a result, when the mobile communication terminal 1 transmits the IP data upward, the transmission to the wireless transmission path is performed in accordance with the codec timing of the mobile communication terminal 1, and the delay caused in relation to the radio access is reduced. It becomes small and the transmission delay between transmission and reception terminals is reduced.

As described above, the mobile packet communication system of the present invention is suitable for the case of transmitting IP packets of real-time system data requiring real-time, such as voice or moving picture, in a mobile packet communication system using a radio access method such as CDMA. Do.

Claims (9)

When performing real-time IP data communication, based on the transmission data basic information including the codec start time information of the mobile communication terminal, for uplink for transmission of the transmission data continuously in synchronization with the codec period of the mobile communication terminal. A wireless base station for allocating a radio resource and notifying the mobile communication terminal of the result as an uplink transmission schedule; A mobile communication terminal which performs transmission control of a radio frame based on the uplink transmission schedule. A mobile packet communication system comprising a. The method of claim 1, The transmission data basic information includes codec start time information determined by the mobile communication terminal, The uplink transmission schedule created by the wireless base station also includes a codec start timing of the mobile communication terminal. A mobile packet communication system, characterized in that. The method of claim 1, And the mobile communication terminal determines a codec start timing based on the uplink transmission schedule. The method of claim 1, And the communication parameter information according to the service contents of the transmission data is added to the transmission data basic information by a radio base station control apparatus. The method of claim 1, The uplink transmission schedule is generated by a radio base station of a cell and a sector of a moving destination at the time of handover. The method of claim 1, And the mobile communication terminal performs the transmission using a radio resource allocated for each codec period, and, when retransmitting, performs the transmission using a radio resource allocated for best effort. The method of claim 1, And the wireless base station reschedules the uplink transmission schedule to a time-averaged schedule when radio quality is degraded. The method of claim 1, And the radio base station allocates the radio resources to which the delay is minimized. The method of claim 1, And the radio base station changes to this when the radio resource having a delay smaller than the radio resource currently allocated is opened.

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