KR20000057118A - Transmission control without limitation by the number of users - Google Patents

Abstract

The packet transmission control method according to the present invention borrows a first channel among a plurality of channels for a first user among a plurality of existing users in response to a packet reception request, and uses the first channel to create a new channel. This is accomplished by sending a packet to the user.

Description

Transmission control method that is not limited by the number of users {TRANSMISSION CONTROL WITHOUT LIMITATION BY THE NUMBER OF USERS}

The present invention relates to transmission control, and more particularly, to a packet transmission control method and a packet system for the method.

Currently, a W-CDMA system is being developed. The W-CDMA system is applied with a circuit switching system that is once owned by the voice signal user until the communication of the voice signal is terminated once the channel or spreading code is secured by the voice signal user. The W-CDMA system can process not only voice signals but also data packets so that it can cope with the Internet. As such, a W-CDMA system is considered a system in which a circuit switching system and a data packet coexist. The structure of a downlink transmitter in a W-CDMA system is described by "Effects of Orthogonal Spreading and Rake Combining on DS-CDMA Forward Link in Mobile Radio" by Fumiyuki Adachi (IEICE Transactions on Communication Vol.E80-B, N0.11). , November 1997).

1 illustrates the transmission of signals in the downlink when a transmitter is used. All signals are sent in parallel. D1, D2,... , D5 denotes a data packet signal user, and V1, V2,... , V4 represents a voice signal user. This known technique has the following problems.

The first problem is that the capacity of the downlink is determined based on the number of spreading codes present, and more users than the number of spreading codes cannot be accessed regardless of whether the user is a voice signal user or a packet signal user. The reason is that one of the voice signal user and the packet signal user must use the spreading code as the user to access. As such, the number of users who can use the system is substantially limited to the number of spreading codes.

The second problem is that the actual traffic volume is less than the number of users accessing, and as a result, the capacity of the system is not used sufficiently. Fig. 1 shows an example of a voice signal user accessing at the same time and a traffic situation actually occurring. As shown in Fig. 1, the above reason is that the channel is limited based on the actual traffic amount as well as the number of users accessing. As such, the number of users who can substantially use the system is limited based on the number of channels that are limited based on the system itself.

In connection with the above description, communication resource allocation is disclosed in Japanese Patent Laid-Open Publication (JP-A-Heisei 5-252101 corresponding to the US application of November 1, 1991). In this document, an allocation unit includes a unit for distinguishing a subscriber having the highest priority among subscribers opposing each other in a wireless communication network. Available communication resources are allocated to the distinguished subscribers within a short time regardless of the amount of traffic without collisions.

In addition, Japanese Patent Laid-Open Publication (JP-A-Heisei 10-32597) discloses a wireless ATM-LAN transmission system. In this document, a wireless base station as a parent station includes first and second units. The first unit manages resources in its service area by using a combination of chip rate and spreading code in CDMA. The second unit allocates resources based on a combination of spreading code and chip speed according to a service request from a wireless terminal in the service area or an ATM terminal on the ATM-LAN side. The wireless terminal receives a plurality of spreading codes and a plurality of chip rates from a parent station and sets the spreading code and the chip rate to change the transmission rate to an optimal value.

Further, Japanese Patent Laid-Open Publication (JP-A-Heisei 9-270767) discloses a spread spectrum communication device. In this document, the primary modulating section 3, 4 multiplies the digital information signal from the inputs 1, 2 with a carrier signal such as a sine wave to produce a narrow band signal. A secondary modulating section 5 multiplies the narrowband signal of the picture with a spreading code a to produce a spreading signal 7. The sub-modulator 6 multiplies the narrowband signal of the sound by the spreading code b to generate the spreading signal 8. An adder adds the spread signal 7 and spread signal 8. The spread spectrum communication apparatus further includes a transmitter 10, a transmit antenna 11, and a receive antenna 21. The receiver 22 also generates a code multiple signal 24. The divider 23 distributes the code multiplexed signal into two. The primary demodulating section 25 multiplies the spreading code a with the code multiplex signal 24. The sub demodulator 26 multiplies the spreading code b by the code multiplex signal 24. The spread spectrum communication apparatus further includes second demodulation units 27 and 28 and output units 29 and 30.

In addition, Japanese Patent Laid-Open Publication (JP-A-Heisei 10-190621) discloses a radio resource control method. In this document, physical radio resources are divided into consecutive frames in the time direction. The frame includes slots 16, 17 and 18 of various sizes. The slot represents a predetermined allocation ratio of physical radio resources included in each frame and may be individually allocated to different radio connections. The first dimension of the frame is time and the second dimension is time, frequency or code. Slots represent different sizes in the second dimensional direction. The first predetermined integer of the slot of the first size may be exchanged within the module with another integer of the slot having the different size.

In addition, Japanese Patent Laid-Open No. JP-A-Heisei 10-112698 corresponding to the US application of September 27, 1996 discloses a wireless communication device. In this document, a reduced gain spread spectrum communication system 6 includes transceivers connected to a base station 10. A spreading unit 28 is also included to spread the digital packet 26 representing the sound by using a spreading sequence length shorter than the spreading gain available for a given transmission band. The spreading unit 28 may spread the digital packet representing the data by using a spreading sequence length longer than the spreading sequence length for the sound.

It is therefore an object of the present invention to provide a transmission system in which the number of users is not limited by the number of spreading codes and a transmission control method for the transmission system.

Another object of the present invention is to provide a transmission system in which the number of users is not limited by the number of channels and a transmission control method for the transmission system.

In one aspect of the present invention, the packet transmission control method according to the present invention borrows a first channel of a plurality of channels relating to a first user among a plurality of existing users in response to a packet reception request. By using a channel of 1 is achieved by sending a packet for a new user.

Here, in the above-mentioned borrowing, the receiving operation by the first existing user can be stopped in response to a request for receiving a packet from the new user.

Further, in the above borrowing, the spreading code can be assigned to the new user in response to a request for receiving a packet from the new user. At this time, in the above transmission, a packet can be transmitted to a new user by using the first channel and the assigned spreading code.

It is preferable that the first channel is a voice channel. In the borrowing in this case, the first channel can be monitored in response to a monitor request generated in response to a request for receiving a packet, and the receiving operation by the first existing user is performed by the unvoiced portion of the first channel. The voiceless portion is stopped when it is detected. Further, in the above transmission, the reception operation by the new user is stopped when the audio portion of the first channel is detected after the unvoiced portion of the first channel is detected. Further, the reception operation by the first existing user is resumed when the first audio portion is detected after the unvoiced portion of the first channel is detected. Further, in the above borrowing, the spreading code assigned to the first existing user can be assigned to the new user in response to a request for receiving a packet from the new user.

It is also preferable that the first channel is a data channel. In the borrowing in this case, the timeslot and spreading code assigned to the first existing user can be assigned to the new user in response to a request for receiving a packet from the new user. Also, in transmission, a packet for a first existing user is put into standby while being transmitted to a new user by using the assigned time slot and the assigned spreading code.

Further, in the packet transmission control method, another channel is borrowed for another existing user when the channel is used for an existing user, and another packet is transmitted to the new user by using another channel.

In order to achieve another object of the present invention, a packet transmission control device is composed of a control unit and a base station. The control unit monitors the transmission status to the existing user through the channel in response to the monitor request, and controls the new user to receive the packet. The base station outputs a monitor request to the control unit in response to a request for receiving a packet from the new user, and transmits the packet for the new user in response to the control for the new user by the control unit.

If the first channel is a voice channel, the control unit controls the existing user to stop the receiving operation when the control unit detects the unvoiced portion of the channel, and controls the base station to transmit a packet for the new user. In addition, the control unit controls the existing user to resume the receiving operation when the control unit detects the voice portion of the channel, and controls the base station to stop transmitting the packet to the new user. It is also preferable that the base station allocates a spreading code for a new user in response to a packet reception request.

In addition, when the channel is a data channel, the base station allocates a spreading code and timeslot to a new user in response to a packet reception request. In this case, the base station includes a buffer in which the packet is buffered. The control unit also controls the base station to transmit packets for new users by using time slots in accordance with the storage state of the packets in the buffer. In addition, the control unit monitors the transmission status to other existing users through other channels in response to the monitor request, and controls the new users to receive packets. The base station transmits the packet to the new user in response to the control of the new user by the control unit.

1 is a diagram showing a channel of a packet transmission control method according to the related art.

Fig. 2 is a system block diagram showing the structure of a packet transmission control system according to the first embodiment of the present invention.

Fig. 3 is a block diagram showing a signal circuit used in the transmission control system according to the first embodiment of the present invention.

Fig. 4 is a flowchart showing the operation of the packet transmission control system according to the first embodiment of the present invention.

5 is a diagram illustrating the vacancy of a data packet.

Fig. 6 is a flowchart showing the operation of the packet transmission control system according to the second embodiment of the present invention.

7A to 7D are time charts showing the use of data packets.

<Explanation of symbols for main parts of drawing>

UD1: one user

UV1 to Uvn, UD2 to UDn: multiple users

Hereinafter, a W-CDMA transmission control system according to the present invention will be described in detail with reference to the accompanying drawings.

2, the W-CDMA transmission control system includes a base station control unit (BTC) 1, an ATM interface unit 2, a base station (BS) 3, a W-CDMA interface unit 4, and It consists of a mobile station (MS) 5.

The base station controller 1 receives a signal from the network and sends it to the base station 3. The base station 3 sends the signal to the mobile station 5 via the W-CDMA interface 4. In the W-CDMA interface unit 4, the received signal is distinguished by using a spreading signal unique to the user.

As shown in FIG. 3, in the base station 3, the signal of the user USER 1 is first modulated as it arrives through the ATM interface unit 2 (step S1). The spreading code is modulated again and the primary modulated signal is converted into a secondary modulated signal (step S2). The secondary modulated signal is added to signals of other users USERi and USERk modulated in the same manner (step S3), and then the spreading code is modulated (step S4). Thereafter, the carrier wave is modulated and sent (step S5). In this manner, signals of all users USER1, USERi, and USERk are transmitted in parallel.

4 shows a process of the transmission control method according to the first embodiment of the present invention as a time sequence. Assume that a data packet signal user UD1 is newly generated as a mobile station. If there is a spreading code that is not used at the time of occurrence, communication is executed by using the spreading code. Suppose all spreading code is already in use. At this time, the data packet signal user UD1 borrows the channel of the already existing voice signal user UV1, that is, the spreading code of the voice signal user UV1.

The data packet signal user UD1 sends the packet reception request 11 to the base station BS 3 described above (step D1). The base station (BS) 3 determines whether all spreading codes are already used. In the case where all spreading codes are already used, the base station (BS) 3 already determines the voice signal user UV1 that can lend the spreading code in consideration of the statistical properties of the existing voice signal user. Thereafter, the base station assigns a spreading code to the voice signal user UV1 (step B1). The data packet signal user UD1 that has received the spreading code enters a waiting state (step D2). The base station (BS) 3 sends a monitor request to the base station control unit BTC 1 in response to a reception request from the data signal user UD1 (step A1). The base station control unit BTC 1 starts to monitor the voice signal for the voice signal user UV1 in response to a monitor request from the base station BS 3.

Assume that the unvoiced portion of the voice signal to the voice signal user UV1 is detected by the base station control unit BTC 1 (step A2). The detection of the silent portion is informed to the data packet signal user UD1 via the base station BS 3, and the data packet signal user UD1 enters a state of ready to receive (step D3).

Almost at the same time as the data packet signal user UD1 enters the reception ready state, the packet 12 is sent from the base station BS 3 to the data packet signal user UD1 (step B2). The data packet signal user UD1 starts receiving the packet 12 (step D4). At the same time, the voice signal user UV1 is controlled by the base station control unit BTC 1 via the base station BS 3 so as to stop reception from the time point at which the reception by the data packet signal user UD1 is started (step). V2). However, the data packet signal user UD1 continues to receive.

When detecting the voice portion of the voice signal, the base station controller (BTC) 1 informs the data packet signal user UD1 of the detection of the voice portion via the base station (BS) 3 (steps A3 and D5). The base station BS stops transmitting the data packet 12 in accordance with the information. The data packet signal user UD1 also stops receiving data packets at the same time (step D6), and enters the standby state again. The audio signal user UV1 resumes reception of the audio signal in response to the information (step V3). The base station control unit (BTC) 1 continues to monitor the voice signal for the voice signal user UV1 and finds the next unvoiced part. The above process continues until the data packet signal user UD1 issues a request to finish receiving the packet (step D7). The base station control unit (BTC) 1 stops the monitoring operation at the reception end request of the packet via the base station (BS) 3 (step A4).

In the first embodiment, data packets of other users are sent by using the channel or spreading code of the voice signal user. In this case, by using the spreading code of another data packet signal user, the data packet can be sent as follows. In the first embodiment, when a new data packet signal user occurs, the user is allowed. However, by using the spreading code, a data packet signal user who has already started communication can borrow the spreading code of another user to cope with the transmission rate. Further, even if a spreading code is borrowed from one user of the first embodiment, the spreading code can be borrowed from a plurality of users. In the above case, the above-described operation is executed for each spreading code.

5 shows a transmission system according to a second embodiment according to the present invention. In the second embodiment above, the voice signal user is not considered. As shown in Fig. 5, it is assumed that only a packet signal user exists. Usually, the arrival of a packet is not continuous but intermittent. There is sometimes a gap between a packet and the next packet that arrives. For this reason, there is a slot which is not used, as shown by the diagonal line in FIG. Such a slot is a slot available to other users.

It is preferable that the base station control unit (BTC) 1 monitor the arrival state of the packet and the storage state of the arrived packet in the buffer. When the arrival of a packet is detected, the detection is known to each user each time it is detected. However, a packet is different from a voice signal, so that some delay causes the packet to wait. In the transmission control system of the second embodiment, the spreading code and the slot time to be borrowed are known to other users in advance.

As shown in Fig. 6, the new packet signal user UD1 sends a packet reception request to the base station BS 3 in step D1. The base station (BS) 3 determines the existing packet signal user UD2 having a spreading code borrowed from the data packet signal user UD1 according to the result monitored by the base station control unit BTC 1. The base station (BS) 3 informs the new packet signal user UD1 and the existing packet signal user UD2 of the spreading code and the time at which the packet is transmitted to the data packet signal user UD1. In the meantime, the packet for the new packet signal user UD1 arrives at the base station (BS) 3. All packets arriving as above are queued in the buffer (steps B1 to B2).

In step B2, the base station (BS) 3 starts transmission of the packet waiting in the buffer for the new packet signal user UD1. In the meantime, the existing packet signal user UD2 is controlled by the base station control unit BTC 1 via the base station BS 3 to stop reception (steps A2 to A3). That is, the existing packet signal user UD2 lends the slot to the new packet signal user UD1. As such, the transmission control system of the second embodiment includes a step of lending a spreading code and a step of lending a timeslot.

The new packet signal user UD1 receives a packet by using a predetermined number of slots. In step D5, the reception stop request for the packet via the base station BS 3 is sent from the new packet signal user UD1 to the base station control unit BTC 1. Therefore, the service to the new packet signal user UD1 ends. Thereafter, the existing packet signal user UD2 returns to the normal reception state after step A3.

7A to 7 show actual channel conditions. Suppose that 12 packets for the existing packet signal user UD2 arrive or are carried on a time slot as shown in A of FIG. The part without the number is the slot where the packet is not loaded. On the other hand, as shown in FIG. 7B, eight packets for the new packet signal user UD1 arrive at the buffer.

Suppose that one frame consists of four slots and the fourth slot is lent to the new packet signal user UD1. Assume which slot is lent by the base station control unit BTC 1 and recognized by the new packet signal user UD1 and the existing packet signal user UD2. At this time, each packet is mapped as shown in FIG. That is, the packets 1 to 3 for the existing packet signal user UD2 are included in the first to third slots of the first frame. The packet 1 for the new packet signal user UD1 is included in the fourth slot. At this time, as shown in FIG. 7D, the packet 4 for the existing packet signal user UD2 is queued in the buffer. The packet 4 is to be included in the slot 1 of the second frame. Similarly, as shown in FIG. 7D, the packets 5 and 6 wait in the buffer.

As a result, the packets 4, 5 and 6 will wait for one slot in the buffer. The packets 4, 5, 6 for the existing packet signal user UD2 enter three slots of the second frame. The packet 2 for the new packet signal user UD1 enters the fourth slot of the second frame. In the same manner, packets for both the existing packet signal user UD2 and the new packet signal user UD1 enter the third and fourth frames 3 and 4. However, when a packet for the existing packet signal user UD2 is not supplied as shown in Fig. 7A, the first slot is blank.

Thus, the four empty slots shown in A of FIG. 7 are reduced to one, as shown in C of FIG. Instead, the packet 12 for the existing packet signal user UD2 is stored in a buffer. Therefore, the packet for the existing packet signal user UD2 is delayed so that the packet for the new packet signal user UD1 is transmitted while it is in the standby state of the existing packet signal user UD2. When the base station control unit BTC 1 detects that the number of packets for the existing packet signal user UD2 stored in the buffer exceeds a certain allowance, the service for the new packet signal user UD1 is stopped or Another user's channel or spreading code is borrowed.

In the above method, the transmission rate of the new packet signal user UD1 becomes very low. However, multiple spreading codes may be previously borrowed for multiple code transmission. Thus, the transmission speed can be improved. In the third embodiment shown in Figs. 7A to 7D, the arrival of the packet is random or unexpected, whereas the present invention makes the use of slots constant by consciously sending packets for other users waiting in the buffer. It is effective.

The transmission control method according to the present invention has the following effects. The first effect is that it is possible to reduce the waste of the channel in the unvoiced portion of the voice signal. The reason for this is that packets with relatively easy access are transmitted to the unvoiced portion of the voice signal.

The second effect is that even if all channels or spreading codes are occupied, further data packet requests can be accepted. The reason is that the spreading code used by another user is borrowed.

The third effect is that the delay required for the reception of the packet can be reduced. This is because a packet waiting in a buffer can be processed by the system of the present invention so that one user packet can be adjusted to a channel of another user packet.

Claims (18)

In the packet transmission control method, Borrowing a first channel among a plurality of channels for a first user among a plurality of existing users in response to a packet reception request; Transmitting a packet for a new user by using the first channel. The method of claim 1, And said borrowing step comprises the step of stopping a receiving operation by said first existing user in response to a request for receiving said packet from said new user. The method of claim 1, The borrowing step includes assigning a spreading code to the new user in response to a request to receive the packet from the new user, And wherein said transmitting step comprises transmitting a packet for said new user by using said first channel and said assigned spreading code. The method of claim 1, And the first channel is a voice channel. The method of claim 4, wherein the borrowing step, Monitoring the first channel in response to a monitor request generated in response to a request to receive the packet; Stopping the receiving operation by the first existing user when the unvoiced portion of the first channel is detected. The method of claim 5, wherein the transmitting step, Stopping the receiving operation by the new user when the voice portion of the first channel is detected after the unvoiced portion of the first channel is detected; And resuming the receiving operation by the first existing user when the voice portion of the first channel is detected after the unvoiced portion of the first channel is detected. . The method of claim 4, wherein And said borrowing step comprises allocating a spreading code assigned to said first existing user to said new user in response to a request for receiving said packet from said new user. The method of claim 1, And said first channel is a data channel. The method of claim 8, The borrowing step includes the step of allocating a spreading code and a time slot assigned to the first existing user to the new user in response to a request for receiving the packet from the new user. Control method. The method of claim 9, The transmitting step includes waiting for a packet for the first existing user while a packet is transmitted to the new user by using the time slot and the assigned spreading code. Control method. The method of claim 1, If the channel is used for the existing user, borrowing another channel for another existing user; Transmitting another packet for the new user by using the other channel. In the packet transmission control apparatus, A control unit for monitoring a transmission state to an existing user through a channel in response to a monitor request, and controlling a new user to receive a packet; A base station which outputs the monitor request to the control unit in response to a request for receiving the packet from the new user, and transmits a packet for the new user in response to control of the new user by the control unit Packet transmission control apparatus comprising a. The method of claim 12, The first channel is a voice channel, The control unit controls the existing user to stop the receiving operation when the control unit detects the unvoiced part of the channel, and the base station controls to transmit a packet for the new user. controller. The method of claim 13, The control unit controls the existing user to resume receiving operation when the control unit detects the voice portion of the channel, and controls the base station to stop transmitting the packet to the new user. Packet transmission control device. The method of claim 13, And the base station allocates a spreading code for the new user in response to a request for receiving the packet. The method of claim 12, The channel is a data channel, And the base station allocates a spreading code and a time slot to the new user in response to a request for receiving the packet. The method of claim 16, The base station includes a buffer in which the packet is buffered, And the control unit controls the base station to transmit a packet to the new user by using the time slot according to the storage state in the buffer. The method of claim 12, The control unit monitors a transmission state for another existing user through another channel in response to the monitor request, controls the new user to receive a packet, And the base station transmits a packet for the new user in response to control of the new user by the control unit.