KR100344877B1 - Method for Controlling Transmission Rate of Reverse Traffic Channel in High Data Rate System, Appratus for the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high data rate (hereinafter referred to as HDR) system, and in particular, a reverse traffic that guarantees a high quality service in a reverse wireless link by adjusting a reverse transmission rate according to a type and priority of a service. A method and apparatus for controlling a transmission rate of a channel. The apparatus for controlling the transmission rate of the reverse traffic channel according to the present invention is provided with RAB information about the presence or absence of reverse link congestion from each base station in the active set of the terminal RAB for each base station in the active set A division rate calculator for calculating a division rate, which is an average value of the values, and a rate controller configured to control a transmission rate of traffic transmitted to the base station by receiving the largest maximum division rate BRmax among the division rates and comparing with a threshold value And a transmitter configured to adjust the data transmission speed of the terminal according to the controlled transmission speed and transmit the data to the base station, and by this configuration, reverse activity bit (RAB) information on the presence or absence of congestion of the reverse link from the base station. Receiving and the reverse activity bit value for each base station in an active set Calculating the frequency division ratios, which are average values of R, and the maximum frequency division ratio (BRmax), which is the maximum value of the frequency division ratios, when no congestion occurs at all base stations from the reverse activity bit (RAB) information received from the base station. The method comprises the step of controlling the traffic transmission rate of the terminal by comparison with a set threshold. Accordingly, the present invention has the effect of relieving the overload of the system while ensuring the differential quality of service requirements through the reverse traffic channel of the HDR system without major changes in the system.

Description

Method for controlling transmission rate of reverse traffic channel in HDR system and apparatus therefor {Method for Controlling Transmission Rate of Reverse Traffic Channel in High Data Rate System, Appratus for the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high data rate (hereinafter referred to as HDR) system, and more particularly, to a method and apparatus for controlling a transmission rate of a reverse traffic channel for adjusting reverse transmission rates according to types and priorities of services. will be.

In general, the HDR system has been proposed by Qual. Co., Ltd. as one of the third generation mobile communication systems, and provides only a high speed packet data service excluding a real time voice service.

In particular, the HDR system allocates a separate frequency band for high-speed data service in consideration of the characteristics of voice traffic and data traffic, and adopts various methods for efficient transmission of high-speed data.

For example, the forward link has the following characteristics.

First, the channels are time division multiplexed.

Secondly, the base station transmits data at full power.

Third, the forward traffic transmission rate has various values according to the request of the terminal.

Fourth, it does not support soft handoff.

Fifth, it supports adaptive coding and modulation.

Sixth, it supports antenna diversity.

In addition, the characteristics of the reverse link is as follows.

First, the pilot signal is transmitted in the reverse direction.

Second, the transmission rate of the traffic channel is dynamically determined.

Third, it supports soft handoff.

1 is a diagram illustrating a forward channel structure of a general HDR system.

Referring to FIG. 1, the forward channel structure from the base station (or sector) 11 to the terminal 12 includes a pilot channel 13 and a forward activity channel (hereinafter, abbreviated as FA). ), Reverse Activity channel (hereinafter referred to as RA) channel 16, Reverse Power Control (hereinafter referred to as RPC) channel 17, Traffic channel and control (Control) Channel 14).

The pilot channel 13 is used as a basic signal for system acquisition, and the traffic channel and control channel 14 are used for data to be transmitted and control data. The FA channel 15 informs the terminal 12 whether there is data in the traffic channel and the control channel 14, and the RA channel 16 determines whether the reverse traffic channel is congested according to the amount of reverse traffic. The terminal 12 is notified.

The reverse power control (RPC) channel 17 controls the outgoing power of the reverse link of the terminal 12.

On the other hand, the reverse channels from the terminal to the base station (or sector) are a traffic channel for data transmission, a data rate control (hereinafter referred to as DRC) channel, a reverse rate indicator channel and a pilot ( Pilot) channel.

In this case, the terminal transmits a transmission rate value to be transmitted through the DRC channel to the base station to be transmitted, and the base station transmits data at the requested transmission rate. In addition, when the terminal transmits data through the traffic channel, the base station (or sector) informs the base station of the current transmission rate through the reverse rate indicator to facilitate demodulation.

The reverse traffic channel has six transmission rates as shown in Table 1. The terminal transmits at one of the transmission rates shown in Table 1 below, and the terminal may increase or decrease the transmission rate of the reverse traffic channel, which is a reverse rate activity transmitted through the RA channel, which is a forward rate limit and a forward channel. Determined by the value of the Reverse Activity Bit (hereinafter abbreviated as RAB).

Bit rate (kbps) Max payload (bits) Null 0 4.8 232 9.6 488 19.2 1000 38.4 2024 76.8 8168

The rate limit value is included in the reverse rate limit message of FIG. 2 transmitted by the base station, and the message includes rate limit information for all terminals.

2 is a diagram illustrating a general reverse rate limit message structure.

Referring to FIG. 2, the reverse rate limit message includes fields for containing message ID, a rate limit value, a rate limit value, and information on reserved bits. In this case, since the base station supports a total of 29 terminals, the base station transmits 29 rate limit values in sequence.

Here, the message ID is set to 0x01, and the field for including the rate limit value is set to 1 when the rate limit value of the corresponding terminal is included.

The rate limit value field is a field indicating the maximum rate that the terminal can transmit and is set according to the information bits shown in Table 2 below. When a call is connected and the rate limit message is not received, the terminal uses 9.6 kbps as the default value of the rate limit value.

The rate limit value message is transmitted to the terminal as needed by the base station.

If the new rate limit value is smaller than the previous value, the new rate limit value is used immediately. If the new rate limit value is larger than the previous value, the new rate limit value is used after 32 slots.

Bit information Maximum transfer rate of terminal 0x0 4.8 kbps 0x1 9.6 kbps 0x2 19.2 kbps 0x3 38.4 kbps 0x4 76.8 kbps 0x5 153.6 kbps

Finally, the reserved bit field is a reserved bit, the length of which is variable.

The terminal receiving the reverse rate limit message controls the reverse rate according to the block configuration of FIG. 3.

3 is a block diagram of a terminal for reverse rate control of a general HDR system.

Referring to FIG. 3, the terminal for controlling the reverse rate includes a receiver 20, a transmitter 21, a rate controller 22, and a transmitter 23.

The RAB indicating whether congestion of the reverse channels through the RA channel, which is one of the forward channels, is provided to the rate controller 22 through the receiving end 20 of the terminal.

The RAB information is set using the reverse received power received from the base station, and its value is changed in units of RABLength. This value has a value of 0 or 1, and a value of 1 means congestion, and a value of 0 means that the reverse link does not congest.

The transmission rate controlled by the transmission rate controller 22 is provided to the transmission unit 23, and the transmission unit 23 adjusts the rate of data that the terminal intends to transmit to the base station and transmits it to the base station through the transmission end 21. Will be done.

The terminal controls the reverse data rate of the terminal through the process as shown in FIG.

4 is a flowchart illustrating a reverse rate control method according to the prior art.

Referring to FIG. 4, the terminal receives an RAB through an RA channel from a base station in an active set (S30).

In this case, the bit values of all the RABs transmitted from the base station (or sector) in each active set are determined (S31). If at least one or more RABs is 1 and the current transmission rate of the terminal is less than or equal to 9.6 kbps, the transmission rate is not increased. Do not (S33).

However, if at least one RAB becomes 1 and the current transmission rate of the terminal is transmitting a speed of 19.2 kbps or more, the transmission rate is reduced to 1/2 (S34).

That is, when the terminal receives a case in which the reverse activity bit (RAB) is 1 from at least one of the base stations in the active set managed by the terminal when the new packet is transmitted, the terminal reduces the transmission rate or the transmission rate is 9.6 kbps or less. Maintains the current rate.

If all of the received RAB values are set to 0 for all base stations in the active set, and the packet is being transmitted before transmitting a new packet (S35), it may be transmitted at twice the previous transmission rate (S36). This is to sequentially increase the reverse rate.

In addition, since the transmission rate of the reverse traffic channel cannot be greater than the rate limit value, the increased rate is compared with the rate limit value and transmitted at a smaller value.

Every communication service has its own service quality and relative priority according to service type, and in HDR system, it is necessary to provide differential service according to service type and priority. However, the current HDR system does not consider these points, and focuses only on resolving congestion of the reverse link, and adjusts the reverse transmission rate regardless of the type of service.

Therefore, it is necessary to consider not only the conventional congestion of the reverse link congestion but also service quality guarantee according to the type and priority of the service.

Accordingly, an object of the present invention has been made in view of the above-described problems of the prior art, a method for controlling a reverse traffic channel rate in an HDR system by adjusting a reverse rate according to the type and priority of a communication service and the same. It is to provide a device for.

According to an apparatus feature of the present invention for achieving the above object, the RAB for each base station in the active set by receiving the reverse activity bit (RAB) information on the presence or absence of reverse link congestion from each base station in the active set of the terminal A division rate calculator for calculating a division rate, which is an average value of the values, and a rate controller configured to control a transmission rate of traffic transmitted to the base station by receiving the largest maximum division rate BRmax among the division rates and comparing with a threshold value And a transmitter for adjusting the data transmission speed of the terminal according to the controlled transmission speed and transmitting the data to the base station.

According to a method feature of the present invention for achieving the above object, receiving the reverse activity bit (RAB) information on the presence or absence of congestion of the reverse link from the base station, and the reverse activity for each base station in the active set Calculating frequency division ratios, which are average values of the bit rate values, and a maximum frequency division ratio (BRmax), which is the maximum of the frequency division ratios when no congestion occurs at all base stations from the reverse activity bit (RAB) information received from the base station; ) And controlling the traffic transmission speed of the terminal by comparing with a preset threshold.

Preferably, the frequency division threshold is a value assigned according to the type and priority of the service of the terminal and has a relatively high threshold when the priority is high.

When the reverse activity bit is 0 from all base stations in the active set, if the maximum frequency division rate is greater than or equal to the threshold value, the transmission rate of the current terminal is maintained, and the maximum frequency division rate is less than the threshold value and the current packet is transmitted. Double the current transmission speed of the transmitting terminal or control the transmission speed of the terminal that is not currently transmitting packets to a transmission speed of 9.6kbps or less.

In addition, when congestion occurs in at least one base station due to reverse activity bit (RAB) information, the current data rate is maintained at a terminal data rate of 9.6 kbps or less, and is currently transmitted at a terminal data rate of 9.6 kbps or more. Control transmission speed by 1/2 of speed.

1 is a diagram illustrating a forward channel structure of a typical HDR system.

2 is a diagram illustrating a general reverse rate limiting message structure.

3 is a block diagram of a terminal for reverse rate control of an HDR system according to the prior art;

Figure 4 is a flow chart showing a reverse rate control method according to the prior art.

5 is a block diagram of a terminal for reverse rate control of a proposed HDR system according to the present invention;

6 is a diagram illustrating an example of reverse rate control operation of an HDR system according to the present invention;

7 is a flowchart illustrating a reverse rate control method according to the present invention.

* Description of the symbols for the main parts of the drawings *

40: receiving end

41: transmitting end

42: frequency division calculator

43: rate controller

44: transmission unit

Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

5 is a block diagram of a terminal for reverse rate control of the proposed HDR system according to the present invention.

Referring to FIG. 5, the terminal for controlling the reverse rate of the present invention includes a receiver 40 and a divider calculator for calculating an average value of RABs of the base stations received at the receiver, that is, a busy ratio. 42, a rate controller 43 for controlling the transmission rate of the terminal from the RAB and the busy ratio, and a transmitter 44 for adjusting the rate of data according to the adjusted transmission rate of the terminal. And a transmitting end 41 for transmitting the adjusted data to the base station.

In the terminal according to the present invention having such a configuration, the RAB, which is information transmitted from the base station through the RA channel, is provided to the rate controller 43 and the frequency division calculator 42 through the receiving end 40 of the terminal.

The frequency division calculator 42 calculates a busy ratio, which is an average RAB value for each base station, from the RAB information provided from each base station in the active set of the terminal, and provides it to the rate controller 43. This Busy Ratio is an average of the RAB values received during the window size period of the RAB, and represents the average congestion degree of the reverse channel for each base station. The division ratio calculated by the division ratio calculator 42 is calculated one for each base station in the active set, and the maximum of these division ratios is supplied to the rate controller 43.

The rate controller 43 inputs the RAB information provided from the receiving end 40 and the maximum frequency division rate BRmax information provided by the frequency division rate calculator BRC to adjust the transmission rate of data to be transmitted by the corresponding terminal. Perform the procedure to

In addition, the rate controller 43 has a threshold value BR _th of a busy ratio set according to the type and priority of a service of a terminal, and a threshold of a relatively high frequency division ratio is set for a high-priority service. The value BR _th is assigned.

That is, the rate controller 43 compares not only the RAB information but also the maximum frequency division rate BRmax and the division rate threshold BR _th to set the transmission rate of reverse traffic.

The transmitter 44 adjusts the speed of the corresponding traffic using the value controlled by the data rate controller 43 and provides the transmitter 41 to the transmitter 41.

Therefore, the transmitting end 41 adjusts the transmission rate of the corresponding traffic according to the service type and priority used by the terminal, and transmits it to the base station.

Transmission rate control in the terminal will be described in detail with reference to FIG. 6.

6 is a flowchart illustrating a reverse rate control method according to the present invention.

In the HDR system proposed in the present invention, the RAB information is received from all base stations in the active set for the corresponding terminal through the RA channel (S50).

In order to know the average congestion state of the RA channel, the frequency division ratio BR averaged over the RAB window size is calculated (S51). In this case, the division ratio is calculated for all base stations in the active set, respectively.

The size of the RAB window size may vary depending on the system. If the value of the RAB window is too large, a change in the channel state over time may not be known properly. If the value of the RAB window is too small, it may be sensitive to a temporary channel change. need.

The frequency division rate BR is a value calculated by the frequency division calculator BRC, and has a large value when the reverse channel communication state is not good, and has a small value when the channel state is good.

That is, if the RAB value represents a channel state during a short RABLength period, the division ratio (BR) value represents an average channel state in terms of the system as a whole. At this time, since each terminal communicates with all base stations in the active set, the division ratio (BR) is calculated one for all base stations in the active set. In addition, since the reverse link is the same as the soft handoff state of the IS-95 system, the maximum division ratio BRmax of the calculated division ratio values is used.

After calculating the maximum frequency division rate (BRmax), the terminal checks the RAB information transmitted from each base station (S52), when at least one RAB is 1, that is, congestion occurs even in one base station In this case, it is determined once again whether the transmission rate of the current reverse link is 9.6 kbps or less (S53), and if the current reverse transmission rate is 9.6 kbps or less, the current transmission rate is maintained (S56).

However, if at least one RAB becomes 1 and the transmission rate of the current reverse link exceeds 9.6 kbps, the current transmission rate is reduced by 1/2 (S54).

On the other hand, by checking the RAB information transmitted from each of the base stations (S52), if all the RAB is 0, that is, if no congestion occurs for all the base stations (R52) the maximum division ratio (RBmax) value calculated in the previous step And a division rate threshold BR _th is performed (S55).

The frequency division rate threshold BR _th is a value determined according to the quality of service and priority of the terminal. When the maximum frequency division rate BRmax is in a range smaller than the frequency division rate threshold BR _th , the corresponding service is provided. This means that the transmission rate can be increased. If the maximum frequency division rate (BRmax) is greater than or equal to the division rate threshold (BR _th ), this means that the transmission rate should not be increased.

Therefore, when the maximum frequency division rate BRmax is greater than or equal to the division rate threshold value BR _th , the current transmission rate is maintained without increasing the current transmission rate of the terminal.

However, if the maximum frequency division rate BRmax is smaller than the frequency division threshold value BR _th , it is determined whether the terminal is currently transmitting a packet (S57). Double the transmission speed (S58), and adjust the transmission speed to 9.6 kbps or less when not transmitting (S59).

As described above, the present invention provides the differential service to the terminal user by adjusting the _frequency division rate threshold BR _th according to the type and priority of the service.

In addition, the rate controller adjusts the reverse rate by using the RAB value, the maximum frequency division rate (BRmax), and the frequency division threshold (BR _th ). In other words, if the reverse active bit (RAB) is 1 in at least one of the base stations in the active set, the current channel state is not good. Therefore, as in the conventional system, the transmission rate is lowered regardless of the service type and priority. I need to give.

However, if the reverse activity bit (RAB) is 0 in all base stations in the active set, it means that the current channel state is good. However, the overall channel condition may not be good, and in this case, a service having a high priority should be provided first, and therefore, whether or not the transmission rate is increased is determined by the maximum frequency division rate (BRmax). That is, the terminal determines whether to increase the transmission speed by comparing the division rate threshold value BR _th determined according to the service type and priority with the current maximum frequency division rate BRmax.

For example, as shown in FIG. 7, if there is one base station in the active set and the RAB window size is 10.

Although the current RAB value is 0, looking at the past RA channel, it can be seen that the state of the current reverse traffic channel is not so good because the case of RAB 1 is more than that of RAB 0 (BRmax = 0.7). have.

In this case, congestion can easily occur due to the increase of reverse traffic. Therefore, when there is no room in the capacity of the traffic channel, it is necessary to preferentially provide a high priority service to a low priority service. For this purpose, the division ratio threshold BR _th is used.

Referring to the example of FIG. 7, assume that service A and service B exist and A has a higher priority than B.

That is, assuming that BR _th (A) is 0.8 and BR _th (B) is 0.4, service A can increase the transmission rate because BRmax <BR _th (A), but because BRmax> BR _th (B), transmission rate Can not increase.

As described above, the present invention has the effect of ensuring the differential quality of service requirements through the reverse traffic channel of the HDR system without significant change in the system.

In particular, the proposed method has the effect of adjusting the transmission speed of reverse traffic without any change in the base station system and relieving the overload of the system.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.

Claims (5)

A division rate calculator configured to receive reverse activity bit (RAB) information on the presence or absence of reverse link congestion from each base station in the active set of the terminal to calculate a division rate which is an average value of RAB values for each base station in the active set; A rate controller which receives the largest maximum frequency division rate (BRmax) among the frequency division rates and controls a transmission rate of the traffic transmitted to the base station by comparison with a threshold value; And a transmission unit for adjusting the data transmission rate of the terminal according to the controlled transmission rate and transmitting the data transmission rate to the base station. Receiving reverse activity bit (RAB) information from the base station on the presence or absence of congestion of the reverse link; Calculating frequency division ratios which are average values of the reverse activity bit values for each base station in an active set; When no congestion occurs at all base stations from the reverse activity bit (RAB) information received from the base station, the traffic of the terminal by comparing the maximum division rate (BRmax), which is the maximum among the division rates, with a preset threshold value. A method of controlling a transmission rate of a reverse traffic channel of a high speed wireless data communication (HDR) system, characterized by controlling the transmission rate. 3. The high speed wireless data communication (HDR) according to claim 2, wherein the frequency division threshold is a value assigned according to the type and priority of the service of the terminal, and has a relatively high threshold when the priority is high. ) A method of controlling a transmission rate of a reverse traffic channel of a system. The transmission rate of the current terminal is maintained when the maximum frequency division rate is greater than or equal to the threshold value when the reverse activity bit is 0 from all base stations in the active set, and the maximum frequency division rate is greater than the threshold value. A high-speed wireless data communication (HDR) system, characterized by doubling the current transmission rate of a terminal that is transmitting a small current packet or controlling a transmission rate of a terminal that is not currently transmitting a packet to a transmission speed of 9.6 kbps or less. A method for controlling the transmission rate of a reverse traffic channel of the. 3. The method of claim 2, wherein when congestion occurs in at least one base station due to reverse activity bit (RAB) information, the terminal data transmission rate is maintained at a terminal data transmission rate of 9.6 kbps or less, and the terminal data transmission exceeds 9.6 kbps. A method of controlling a transmission rate of a reverse traffic channel of a high speed wireless data communication (HDR) system, characterized in that the rate is controlled at 1/2 of the current transmission rate.