JP2006049954A - Base station apparatus and communication control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base station apparatus and a communication control method capable of performing efficient communication. <P>SOLUTION: A data quantity monitoring unit 32 notifies the slot control unit 34 of the communication quantity of each user sharing the same slot. The unit 34 decides to give one of at least two kinds of transmission speeds to each user corresponding to the communication quantity of each user, and decides the assignment of a slot to each radio communication terminal so that the frequency of the assignment of a slot to each radio communication terminal may be a frequency corresponding to the transmission speed given to each radio communication terminal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a base station apparatus that performs scheduling for sequentially allocating slots for communication with a plurality of wireless communication terminals that share slots at the same position in each frame in a time division multiple access scheme, and The present invention relates to a communication control method.

  In a wireless communication system such as PHS (Personal Handyphone System), a data communication service based on a packet communication method has been put into practical use. Also, in a wireless communication system that employs a so-called time division multiple access (TDMA) system, a plurality of wireless communication terminals share the same wireless resource, and each wireless communication terminal is assigned to itself. Communicate with the base station in time (slot).

  The base station controls allocation of slots to a plurality of users (wireless communication terminals). FIG. 7A shows slot allocation of a conventional wireless communication system taking PHS as an example. The horizontal axis indicates the time axis, and one frame is constituted by four slots R1 to R4 in the upstream direction and four slots T1 to T4 in the downstream direction. The leading slots R1 and T1 in the upstream and downstream directions are assigned to the same user (user A). When communication is continued as shown in FIG. 7A, each user is assigned a slot at the same position in each frame.

  In addition, when multiple users share the same slot, after one user uses a predetermined number of frames, the slot assignment is switched from that user to another user, and the other users are similarly notified of the same slot. Use frames. For example, when user A and user B share the same slot as shown in FIG. 7B, a switching time for the base station to perform slot switching processing for each user occurs. For example, as shown in FIG. 7C, after user A communicates using four frames, the slot assignment from user A to user B is switched by the base station, and user B assigns the slot. Use to communicate.

  When a plurality of users share the same slot and perform communication, there is also a communication method in which the same slot is shared among a plurality of users by setting the transmission speed per user to a low speed. For example, when two users share the same slot, the frequency of slot allocation to each user is half that of one user, so that the transmission rate (half rate) is half the normal transmission rate (full rate). There is a method to communicate with. FIG. 7D shows slot allocation by half rate, and user A and user B perform communication while using the same slot alternately frame by frame.

In addition, when four users share the same slot, the transmission rate (quarter rate) is ¼ of the full rate by setting the frequency of slot allocation to each user to one-fourth that of one user. There is also a method of performing communication with. In the case of communication at half rate and quarter rate, the switching time as shown in FIG. 7C does not occur. Non-Patent Document 1 describes a slot designation method and the like in communication at the above half rate and quarter rate.
“Second Generation Cordless Telephone System Standards”, 4.0 edition, Radio Industry Association, March 2002, p. 83-84

  As described above, in a conventional wireless communication system using time division multiple access, a base station repeatedly uses a communication slot and a control slot to disconnect and assign a slot to each user. As described above, since there is an overhead (switching time) for switching users, when a slot is shared by a plurality of users, there is a problem that an execution rate is lowered and efficient communication cannot be performed. It was.

  For example, when 1 slot (32 kbps) is shared by 4 users, if there is no overhead, the transfer rate is 8 kbps per user. However, since there is actually overhead, the transfer rate is 4 kbps per user. It will be about. In addition, since each user cannot perform data communication while the base station performs overhead processing, the radio resources that each user can use for data communication further decrease as the number of users increases. Resulting in.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a base station apparatus and a communication control method capable of performing efficient communication.

  The present invention has been made to solve the above problems, and the invention according to claim 1 is a base station that performs communication in a time division multiple access system and allocates the same slot for communication with a plurality of wireless communication terminals. In the apparatus, for each wireless communication terminal, transmission speed determining means for determining to give one of at least two types of transmission speeds, and the frequency according to the transmission speed given to the wireless communication terminal, A base station apparatus comprising slot allocation means for determining allocation of the slot to a radio communication terminal.

  According to a second aspect of the present invention, in the base station apparatus according to the first aspect, when the transmission rate determining means determines to give each of the wireless communication terminals one of at least two types of transmission rates. The slot assigning means assigns the slot to any one of the wireless communication terminals every 4 slots.

  A third aspect of the present invention is the base station apparatus according to the first aspect, further comprising communication amount acquisition means for acquiring the communication data amount of the wireless communication terminal, wherein the slot allocation means has a large communication data amount. The slot allocation is determined such that the frequency of the slot allocation to the radio communication terminal is higher than that of the radio communication terminal having a small communication data amount.

  According to a fourth aspect of the present invention, the base station apparatus according to the first aspect further comprises an allocation standard degree calculation means for calculating an allocation standard degree indicating the allocation standard of the slot from both the communication data amount and the communication quality. The slot allocating means determines the slot allocation so that the frequency of allocation of the slot to the wireless communication terminal having the largest calculated allocation standard degree is higher than that of other wireless communication terminals. .

  According to a fifth aspect of the present invention, there is provided a communication control method for performing communication by a time division multiple access method and allocating the same slot for communication with a plurality of wireless communication terminals. The communication control method is characterized by deciding to give one of the slots, and allocating the slot to the radio communication terminal so as to have a frequency according to a transmission rate given to the radio communication terminal. .

  According to the present invention, an effect that efficient communication can be performed is obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a base station according to an embodiment of the present invention. Hereinafter, each component in the figure will be described. The antenna 1 transmits and receives radio waves with a wireless communication terminal (user). The transmission / reception unit 2 includes a radio unit 21 and a modem unit 22. The radio unit 21 includes a local oscillator and the like, and converts a received signal into a received IF signal of an intermediate frequency (IF) by mixing a locally transmitted signal of a predetermined frequency with a received signal output from the antenna 1 during reception. And output to the modem unit 22. Further, the radio unit 21 mixes a local transmission signal having a predetermined frequency with a transmission IF signal having an intermediate frequency during transmission, thereby converting the transmission IF signal into a transmission signal having a predetermined frequency and outputting the signal to the antenna 1.

  The modem unit 22 performs a demodulation process on the received signal and a modulation process on the transmitted signal. The modulation / demodulation unit 22 includes a local oscillator and the like, converts the reception IF signal output from the radio unit 21 into a baseband signal having a predetermined frequency, converts the baseband signal into a digital signal, and outputs the digital signal to the control unit 3. . Further, the modem unit 22 converts the digital baseband signal for transmission output from the control unit 3 into an analog signal, converts it into a transmission IF signal of an intermediate frequency, and outputs it to the radio unit 21.

  The control unit 3 includes a data control unit 31, a data amount monitoring unit 32, a quality monitoring unit 33, and a slot control unit 34. The data control unit 31 performs various processes on the data, monitors packets transmitted and received with the wireless communication terminal, notifies the data amount monitoring unit 32 of the packet data amount, and notifies the slot control unit 34 of the number of users. Do. Based on the data amount notified by the data control unit 31, the data amount monitoring unit 32 monitors the communication amount (communication data amount) that is the cumulative amount of data of each wireless communication terminal, and requests from the slot control unit 34. Accordingly, the communication amount is notified to the slot control unit 34.

  The quality monitoring unit 33 detects the communication quality (S / N ratio or frame error rate) of communication with each user by measuring the signal level and the noise level at predetermined time intervals, and stores them in the storage unit 4. . The quality monitoring unit 33 notifies the slot control unit 34 of the detected communication quality in response to a request from the slot control unit 34. In the present embodiment, a frame error rate is used as the communication quality.

  Based on the number of users notified by the data control unit 31, the data amount of the packet notified by the data amount monitoring unit 32, and the communication quality notified by the quality monitoring unit 33, the slot control unit 34 In addition to determining the transmission rate to be given, the allocation of the slot according to the determined transmission rate is determined, and information regarding the determined slot and the like is stored in the storage unit 4. Further, the slot control unit 34 controls packet transmission / reception timing by the radio unit 21 based on the determined slot. The storage unit 4 temporarily stores the communication amount of each wireless communication terminal, information on the determined slot, and the like. The network I / F unit 5 is a communication interface with a public network (not shown).

Next, the operation of the base station according to the present embodiment will be described. This base station dynamically determines slot allocation as follows according to the number of users sharing the same slot. In this embodiment, it is assumed that up to four users can be accommodated in one slot.
(1) In the case of one user, slots are allocated to the user at the full rate.
(2) When the number of users changes from one user to two users, the original user is switched to the half rate to assign the slot, and the new user is assigned to the slot at the half rate.
(3) When the number of users is changed from 2 users to 3 users, one of the original 2 users is switched to the quarter rate and assigned a slot, and a slot is assigned to a new user at the quarter rate.
(4) When the number of users changes from 3 users to 4 users, slots are allocated to each user at the quarter rate.
(5) When two users are connected, three of the four quarter rate slots are assigned to user A, and one of the four quarter rate slots is assigned to user B.

  FIG. 2 shows the state of the slots allocated to three users according to the above (3). As shown in the figure, the same slot is shared by users A, B, and C. In this example, user A is assigned a slot at a half rate, and users B and C are assigned a slot at a quarter rate.

In the case of (3) above, in the present embodiment, one of the following three operations is performed.
(A) Of the two original users, slots are allocated at half rate to the user with the larger communication volume (cumulative amount of data detected within a predetermined time, communication data volume), and the user with the smaller communication volume Assigns slots at the quarter rate, and assigns slots for the quarter rate generated thereby to new users.
(B) Out of the two original users, the communication quality and the communication quality are comprehensively considered, and the communication quality and the communication amount are each scored, and the reciprocal of the communication quality score is multiplied by the communication traffic score. A slot with a half rate is assigned to the user with the highest score, a slot with a quarter rate is assigned to the other user, and a slot corresponding to the resulting quarter rate is assigned to a new user.
(C) Of the two original users, a half rate is assigned to the higher communication quality and a quarter rate is assigned to the lower one.

Also, slots are dynamically allocated as follows during communication by three users.
(A) Of the three users, a slot with a half rate is allocated to the user with the largest traffic, and a slot is allocated with a quarter rate to the remaining two users.
(B) Among the three users, the communication quality and the communication quality are comprehensively considered, and the communication quality and the communication amount are each scored. The score obtained by multiplying the reciprocal of the communication quality score and the communication traffic score is obtained. Allocate slots at half rate for the user with the largest, and allocate slots at the quarter rate for the remaining two users.
(C) A half rate is assigned to a user having the highest communication quality among the three users, and a quarter rate is assigned to the other two users.

  As described above, by making the slot allocation frequency for users with a large amount of communication higher than the frequency of slot allocation for users with a small amount of communication (increasing the transmission speed), more data throughput is required. The communication rate of the user can be increased, and more efficient communication can be realized by effectively using resources.

  In addition, considering the communication volume and communication quality comprehensively, the communication quality and the communication volume are scored, and the slot for the user with the highest score obtained by multiplying the reciprocal of the communication quality score and the communication traffic score is obtained. The frequency of allocation is higher than the frequency of slot allocation to other users because users with a large amount of communication and communication quality have a relatively large amount of communication compared to other users and communication quality is also high. This is because it is considered to be relatively good, so that the waiting time of other users who are waiting for radio resources is shortened by increasing the number of slots assigned to the user and completing the communication earlier. Thereby, more efficient communication can be realized by effectively using radio resources. In this embodiment, the traffic volume and the communication quality are each scored, and the product of the traffic volume and the reciprocal of the communication quality is used as a slot allocation guideline (assignment guideline degree). The frequency of allocation is increased.

  Next, the detailed operation of the base station according to the present embodiment will be described. First, a first operation example will be described along the flowchart shown in FIG. It is assumed that at least one user has already been assigned to the target slot. The data control unit 31 monitors control information transmitted / received to / from the user (wireless communication terminal), and determines whether or not there is a new call connection (step S301). If there is no new call connection, the process returns to step S301 and is repeated.

  On the other hand, when there is a new call connection, the data control unit 31 acquires the number of users to be assigned to the slot based on the transmitted / received data and the user identification information added to the control information, and the slot control unit 34 (step S303). Receiving the notification, the slot control unit 34 first determines whether the number of users as a result of the new call connection is 2 (step S304). When the number of users is 2, the slot control unit 34 determines the transmission rate to be given to each user (user A and user B) as a half rate, and the frequency of slot allocation is based on the half rate. Slots are assigned so as to become (step S305). Subsequently, the process returns to step S301.

  On the other hand, when the number of users is not 2, the slot control unit 34 determines whether or not the number of similar users is 3 (slot S306). If the number of users is not 3, the number of users is 4, and the slot control unit 34 determines the transmission rate to be given to each user as the quarter rate, and the slot allocation frequency is a frequency based on the quarter rate. The slots are allocated as described above (step S307). Subsequently, the process returns to step S301.

  On the other hand, when the number of users is 3, the slot control unit 34 notifies the communication amount notification of the two users (user A and user B) who have already been assigned a slot and are communicating with each other. 32. Each time a packet is transmitted and received, the data control unit 31 notifies the data amount monitoring unit 32 of the data amount of each packet. When notified of the data amount of the packet from the data control unit 31, the data amount monitoring unit 32 reads the communication amount of the corresponding user from the storage unit 4, and updates the communication amount by adding the notified data amount. . When receiving an instruction from the slot control unit 34, the data amount monitoring unit 32 reads the communication amounts of the user A and the user B from the storage unit 4 and notifies the slot control unit 34 (step S308). The communication amount may be a communication amount per predetermined time. In this case, the data amount monitoring unit 32 is obtained by dividing the packet data amount notified from the data control unit 31 by a predetermined time.

  The slot controller 34 notified of the communication amount compares the communication amount of the user A with the communication amount of the user B, and determines whether the communication amount of the user A is larger than the communication amount of the user B (step S309). . When the communication amount of the user A is larger than the communication amount of the user B, the slot control unit 34 determines the transmission rate to be given to the user A as a half rate, and the slot allocation frequency is a frequency based on the half rate. A slot is allocated (slot S310), a transmission rate to be given to the user B and the user C who has newly established a call connection is determined as a quarter rate, and the slot is allocated so that the slot allocation frequency is a frequency based on the quarter rate ( Step S311).

  On the other hand, when the traffic volume of the user A is less than or equal to the traffic volume of the user B, the slot control unit 34 assigns a slot to the user B at a half rate (step S312), and slots the user A and the user C at a quarter rate. Is assigned (step S313). Subsequently, the process returns to step S301. In this way, efficient communication can be performed by dynamically allocating slots according to the number of users.

  FIG. 4 is a flowchart showing an operation for determining the slot allocation frequency by acquiring the communication amount of the connected user at predetermined time intervals in a state where the call is established and the user is connected. The data control unit 31 acquires the number of users to which slots should be allocated based on the transmitted / received data and the user identification information added to the control information, and notifies the slot control unit 34 of the number. Receiving the notification, the slot control unit 34 determines whether the number of users is 3 (step S401). If the number of users is not 3, the process returns to step S301 in FIG.

  On the other hand, when the number of users is 3, the slot control unit 34 instructs the data amount monitoring unit 32 to notify the communication amount of the users (user A, user B, and user C) who are communicating. . Receiving the instruction, the data amount monitoring unit 32 reads the communication amounts of the users A to C from the storage unit 4 and notifies the slot control unit 34 (step S402). Subsequently, the slot control unit 34 compares the communication amount of the user A with the communication amount of the user B, and determines whether or not the communication amount of the user A is larger than the communication amount of the user B (step S403). When the communication amount of the user A is larger than the communication amount of the user B, the slot control unit 34 compares the communication amount of the user A with the communication amount of the user C, and the communication amount of the user A is larger than the communication amount of the user C. Is also determined (step S404).

  When the communication amount of the user A is larger than the communication amount of the user C, the slot control unit 34 determines the transmission rate to be given to the user A as a half rate, and the slot allocation frequency is a frequency based on the half rate. Slots are assigned (slot S405), the transmission rate given to users B and C is determined as a quarter rate, and slots are assigned so that the slot assignment frequency is a frequency based on the quarter rate (step S406).

  On the other hand, if the traffic volume of the user A is less than or equal to the traffic volume of the user C in step S404, the slot control unit 34 allocates a slot to the user C at a half rate (step S407), and the user A and the user B are allocated. Slots are assigned at the quarter rate (step S408). Subsequently, the process returns to step S301.

  In step S403, when the communication amount of the user A is equal to or less than the communication amount of the user B, the slot control unit 34 determines whether the communication amount of the user B is larger than the communication amount of the user C ( Step S409). If the communication amount of the user B is less than or equal to the communication amount of the user C, the process proceeds to step S407. On the other hand, when the communication amount of the user B is larger than the communication amount of the user C, the slot control unit 34 assigns a slot to the user B at a half rate (step S410), and assigns a slot to the user A and the user C at a quarter rate ( Step S411). Subsequently, the process returns to step S301.

  When three users share the same slot by the above-described operation, the half-rate slot is allocated to the user with the largest traffic, and the remaining two users are allocated the slot at the quarter rate. Thus, even if the communication amount of each user changes during communication, efficient communication can be realized by dynamically allocating slots accordingly. The slot allocation frequency may be determined using only the communication quality (S / N ratio, frame error rate, etc.) instead of the communication amount.

  Next, a second operation example according to the present embodiment will be described with reference to FIG. The operations in steps S501 to S507 are the same as those in steps S301 to S307 in FIG. Subsequent to step S506, the slot control unit 34 instructs the data amount monitoring unit 32 to notify the data amount monitoring unit 32 of the communication amount of the users (user A and user B) who have already been assigned a slot and are performing communication. Is notified to the quality monitoring unit 33. Receiving the instruction from the slot control unit 34, the data amount monitoring unit 32 reads the communication amounts of the user A and the user B from the storage unit 4 and notifies the slot control unit 34 of them. Further, the quality monitoring unit 33 that has received an instruction from the slot control unit 34 reads out the communication qualities of the user A and the user B from the storage unit 4 and notifies the slot control unit 34 (slot S508).

The slot control unit 34 notified of the communication amount and communication quality scores the communication amount and communication quality of each user, and calculates an allocation standard degree that is a product of the communication amount and the reciprocal of the communication quality (step S509). . Specifically, if the traffic is 5 kbps and the reciprocal of the frame error rate representing the communication quality is 5 × 10 ⁵ , the user's allocation standard degree is 5 × 5 × 10 ⁵ = 2.5 × 10 ^6. . Subsequently, the slot control unit 34 compares the user A allocation standard degree (Pa) with the user B allocation standard degree (Pb), so that the user A allocation standard degree is higher than the user B allocation standard degree. It is determined whether it is larger (step S510). If the user A allocation guideline is greater than the user B allocation guideline, the slot control unit 34 assigns a slot to the user A at a half rate (step S511), and assigns a slot to the user B and the user C at a quarter rate ( Step S512). Subsequently, the process returns to step S501.

  On the other hand, if the user A allocation guideline is less than or equal to the user B allocation guideline, the slot control unit 34 assigns slots to the user B at half rate (step S513), and the user A and user C to the quarter rate. Then, slots are allocated (step S514). Subsequently, the process returns to step S501. In this way, efficient communication can be performed by dynamically allocating slots according to the number of users.

  FIG. 6 is a flowchart showing an operation of determining the allocation frequency of the slot by acquiring the allocation standard degree of the connected user every predetermined time in a state where the call is established and the user is connected. The operation in step S601 is the same as the operation in step S401 in FIG. When the number of users is 3, the slot control unit 34 instructs the data amount monitoring unit 32 to notify the communication amount of users (users A to C) who are performing communication, and the communication quality of those users. Is notified to the quality monitoring unit 33. Receiving the instruction from the slot control unit 34, the data amount monitoring unit 32 reads the communication amounts of the users A to C from the storage unit 4 and notifies the slot control unit 34 of the communication amounts. Further, the quality monitoring unit 33 that has received an instruction from the slot control unit 34 reads out the communication qualities of the users A to C from the storage unit 4 and notifies the slot control unit 34 (slot S602).

  The slot control unit 34 notified of the communication amount and communication quality calculates the allocation standard degree, which is the product of the communication amount and communication quality of each user, in the same manner as in step S509 in FIG. 5 (step S603). By comparing the allocation standard degree (Pa) and the user B allocation standard degree (Pb), it is determined whether or not the user A allocation standard degree is larger than the user B allocation standard degree (step S604). If the user A allocation guideline is greater than the user B allocation guideline, the slot control unit 34 determines whether the user A allocation guideline (Pa) is greater than the user C allocation guideline (Pc). (Step S605).

  If the user A allocation guideline is greater than the user C allocation guideline, the slot control unit 34 assigns slots to the user A at half rate (step S606), and assigns slots to the user B and user C at the quarter rate (step S606). Step S607). Subsequently, the process returns to step S601.

  On the other hand, if the user A allocation guideline is less than or equal to the user C allocation guideline in step S605, the slot control unit 34 assigns a slot to user C at half rate (step S608), and user A and user A Slots are assigned to B at a quarter rate (step S609). Subsequently, the process returns to step S601.

  In step S604, if the user A allocation guideline is less than or equal to the user B allocation guideline, the slot control unit 34 determines that the user B allocation guideline (Pb) is the user C allocation guideline ( It is determined whether it is larger than Pc) (step S610). If the user B allocation guideline is less than or equal to the user C allocation guideline, the process advances to step S608.

  On the other hand, when the user B allocation guideline is larger than the user C allocation guideline, the slot control unit 34 assigns a slot to the user B at a half rate (step S611), and the user A and the user C at a quarter rate. A slot is assigned (step S612). Subsequently, the process returns to step S601. Thus, even if the communication amount of each user changes during communication, efficient communication can be realized by dynamically allocating slots accordingly.

  Next, an example of slot allocation by the above-described operation is shown. Assume that user A and user B communicate with the base station in the same slot, user C newly connects to the base station, and user C also communicates in the same slot. Assuming that the traffic volume of user A and user B at the time of connection of user C is 5 kbps and 2 kbps, respectively, in the first operation example, according to the operation shown in FIG. Are assigned to user B and user C at a quarter rate. Subsequently, assuming that the communication traffic of users A to C during communication is 5 kbps, 2 kbps, and 6 kbps, respectively, user C has the largest traffic according to the operation shown in FIG. Shifting to the half rate, the user A shifts from the half rate to the quarter rate.

Also, assume that user A and user B communicate with the base station using the same slot, and the frame error rates of user A and user B are 1 × 10 ⁻⁶ and 2 × 10 ⁻⁶ , respectively. . In this state, when user C newly connects to the base station and performs communication in the same slot according to the second operation example, the following occurs. Assuming that the traffic volume of user A and user B is similar to the above, 5 × 10 ⁶ , which is a value obtained by simply multiplying the traffic volume of user A and the reciprocal of the frame error rate, is the user A allocation guideline level. 1 × 10 ⁶ is set as the user B allocation standard degree.

Therefore, in this case, according to the operation shown in FIG. 5, a slot with a half rate is allocated to user A having a large allocation standard, and a slot is allocated to user B and user C, which is a new call, at a quarter rate. Subsequently, the traffic volume of the users A to C during communication is the same as that described above, and the frame error rates of the users A to C are 1 × 10 ⁻⁶ , 2 × 10 ⁻⁶ , and 8 × 10 ^{− respectively. If it is 7} , the allocation standard degree of user A to user C is 5 × 10 ⁶ , 1 × 10 ⁶ , and 7.5 × 10 ⁶ , respectively. Since the user with the highest allocation standard is user C, a slot is allocated to user C at half rate instead of user B. Thus, according to the operation shown in FIG. 6, the transmission speed of the user C is increased as described above.

  Note that the number of users accommodated in one slot is not limited to this embodiment, and the transmission speed lower than the full rate is not limited to the half rate and the quarter rate. Further, by performing modulation using a more advanced modulation scheme (multi-level modulation such as 8BPSK, 16QAM, 32QAM, etc.), the transmission rate that has been lowered due to being assigned to the half rate or quarter rate may be improved. Furthermore, if the S / N ratio is used as the communication quality, the reciprocal of the score need not be taken.

  Further, the method of giving the transmission rate to each user using the allocation standard degree is not limited to the present embodiment, and a higher transmission rate may be given to the user having the smallest allocation standard degree. . In that case, if there is little data to be transmitted or received by a user with low communication quality, wait for free radio resources by increasing the number of slots assigned to that user and completing communication early. The waiting time of other users can be shortened.

  In addition, the two operation examples described above are operation examples when a new call is added, but when a call is disconnected and the number of users decreases, the slot allocation frequency is determined in the same manner. Can do. In this case, step S301 in FIG. 3 and step S501 in FIG. 5, which are the flowcharts in operation example 1 and operation example 2, determine “whether the call is disconnected?”, Step S308 in FIG. The operation of “acquisition of communication amount” is replaced with the operation of “acquire communication amount d and communication quality q of the user who is continuing communication” in step S508 of FIG.

  As described above, in the present embodiment, when a plurality of wireless communication terminals share a slot at the relatively same position in each frame, the slot control unit 34 transmits at least two types of transmission rates to each wireless communication terminal. Give one of them. In particular, in the example of the present embodiment, when the number of users is 3, each of at least two types of transmission rates is assigned to one of the wireless communication terminals. In addition, the slot control unit 34 assigns slots for communication with each wireless communication terminal so that the frequency of slot assignment to each wireless communication terminal becomes a frequency according to the transmission rate given to each wireless communication terminal. decide. As a result, there is no overhead for switching between wireless communication terminals, so that the transfer rate is improved as compared with the prior art and efficient communication can be performed.

  Further, during the communication, the slot control unit 34 switches the transmission rate given to each wireless communication terminal according to the communication amount or communication quality of each wireless communication terminal, so that the effective use of wireless resources and the service quality (transfer rate) can be improved. Can be improved.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and includes design changes and the like within a scope not departing from the gist of the present invention. It is.

It is a block diagram which shows the structure of the base station by one Embodiment of this invention. FIG. 3 is a schematic reference diagram showing a state of slots when three users share the same slot in the embodiment. It is a flowchart which shows operation | movement of the base station by the embodiment. It is a flowchart which shows operation | movement of the base station by the embodiment. It is a flowchart which shows operation | movement of the base station by the embodiment. It is a flowchart which shows operation | movement of the base station by the embodiment. It is a schematic reference figure which shows the mode of the slot in the conventional radio | wireless communications system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antenna, 2 ... Transmission / reception part, 3 ... Control part, 4 ... Memory | storage part, 5 ... Network I / F part, 21 ... Radio | wireless part, 22 ... Modulation / demodulation part 31... Data control unit, 32... Data amount monitoring unit, 33... Quality monitoring unit, 34.

Claims (5)

In a base station apparatus that performs communication in a time division multiple access method and assigns the same slot to communication with a plurality of wireless communication terminals,
Transmission rate determining means for determining to give one of at least two types of transmission rates to each wireless communication terminal;
Slot allocation means for determining allocation of the slot to the wireless communication terminal so as to have a frequency according to a transmission rate given to the wireless communication terminal;
A base station apparatus comprising:   When the transmission rate determining unit determines to give each of the wireless communication terminals one of at least two types of transmission rates, the slot allocating unit determines whether the wireless communication terminal is one of the wireless communication terminals. The base station apparatus according to claim 1, wherein the frequency of assigning the slots is every four slots. A communication amount acquisition means for acquiring a communication data amount of the wireless communication terminal;
The slot allocation means determines the slot allocation so that the frequency of allocation of the slot to the wireless communication terminal with a large amount of communication data is higher than that of the wireless communication terminal with a small amount of communication data. The base station apparatus according to claim 1. An allocation guideline degree calculating means for calculating an allocation guideline degree indicating an allocation guideline of the slot from both the communication data amount and the communication quality;
The slot allocating unit determines the slot allocation so that the frequency of allocation of the slot to the wireless communication terminal having the largest calculated allocation standard degree is higher than that of other wireless communication terminals. Item 8. The base station apparatus according to Item 1. In a communication control method for performing communication in a time division multiple access method and assigning the same slot to communication with a plurality of wireless communication terminals,
Assigning one of at least two types of transmission rates to each wireless communication terminal, and assigning the slot to the wireless communication terminal so as to have a frequency according to the transmission rate given to the wireless communication terminal The communication control method characterized by determining.

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