KR20020011557A - Method for Controlling Transmission Rate of Reverse link Traffic Channel in High Data Rate System, Appratus for the same - Google Patents

Abstract

PURPOSE: A method of controlling a data rate of a reverse traffic channel in an HDR(High Data Rate) system is provided to give different services to terminal users by controlling a reverse rate according to service kinds and priority. CONSTITUTION: An HDR(High Data Rate) system receives RABs(Reverse Activity Bits) for reverse link congestion information from each base station of an active set(S50). If congestion does not occur in every base station, the HDR system increases values of CZB(Consecutive Zero Bit)(S56). The HDR system controls a traffic data rate of a terminal by comparing a value of the CZB with a preset critical value as well as values of the RABs received from the base stations.

Description

Method for controlling transmission rate of reverse traffic channel in HDR system and apparatus therefor {Method for Controlling Transmission Rate of Reverse link 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 is 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 requires a separate frequency band for high-speed data service, and has adopted 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 selects and transmits a transmission rate to be transmitted and a base station to be transmitted through the DRC channel, and the corresponding 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 transmission rate transmitted by the base station (or sector) to facilitate the 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, it is used as the rate limit value immediately. If the new rate limit value is larger than the previous value, the new 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 corresponding 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 of the mobile terminal, 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-mentioned problems of the prior art, a method for controlling a reverse traffic channel rate in an HDR system for adjusting 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, by receiving the reverse activity bits (RAB) that is the congestion information of the reverse link from each base station in the active set of the terminal, congestion is applied to all base stations in the active set A continuous zero bit counter that increases the value if it does not occur, a rate controller that receives the value of the counter and controls a rate of reverse traffic by comparing with a threshold value, and a traffic rate of the terminal according to the controlled rate It characterized by consisting of a transmission unit for transmitting to the base station by adjusting the.

According to a method feature of the present invention for achieving the above object, receiving a reverse activity bit (RAB) for the reverse link congestion information from each base station in the active set, and congestion occurs for all the base stations If not, increasing the continuous zero bit (CZB) value and comparing the continuous zero bit (CZB) value with the preset threshold value as well as the reverse activity bit (RAB) value received from the base station. The feature is achieved, including controlling the traffic rate.

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

If the continuous zero bit (CZB) value is smaller than the threshold, the current terminal maintains the transmission rate, and if the continuous zero bit (CZB) value is greater than or equal to the threshold and is transmitting the current packet, It is characterized in that the transmission rate is increased to twice the current transmission rate, or the current transmission rate of the terminal that is not currently transmitting packets is controlled to 9.6 kbps or less.

In addition, congestion occurs in at least one or more base stations due to the reverse activity bit (RAB) information, and maintains the current rate at a reverse traffic rate of 9.6 kbps or less, and at a terminal traffic rate of 9.6 kbps or less, It is characterized by controlling at a speed of 2.

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

2 is a diagram illustrating a general reverse rate limit 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 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: Continuous Zero Bit Counter

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 reverse rate control according to the present invention increases by one when the RAB is "0" for the receiver 40 and all base stations in the active set received by the receiver 40. A continuous zero bit (CZB) counter 42, a rate controller 43 for controlling the transmission rate of the terminal from the RAB value and the continuous zero bit (CZB) value, and a rate of data in accordance with the adjusted rate of the terminal It comprises a transmitter 44 for adjusting the transmitter, and a transmitter 41 for transmitting the adjusted data of the transmitter 44 to the base station.

The continuous zero bit (CZB) counter 42 is used to indicate how many consecutive cases where all of the RABs provided from all base stations in the active set of the terminal are all "0", and when all of the RABs are "0". Increment one consecutive zero bit (CZB) counter each time.

If the RAB value is received as 1 for at least one of the base stations in the active set of the terminal, the counter is set to zero. The reason for using the continuous zero bit (CZB) counter 42 is reverse only if it is convinced that the reverse channel is not congested for low priority services, i.e. if all RABs are zero consecutively. This is to increase the traffic transmission speed.

The rate controller 43 inputs the RAB information provided from the receiving end 40 and the continuous zero bit CZB value provided by the continuous zero bit counter CRC to receive the data to be transmitted by the corresponding terminal. Perform the process to adjust the speed.

That is, the rate controller 43 has a threshold value CZB _th of the consecutive zero bits CZB according to the type and priority of the service of the terminal, and a relatively small continuous zero bit threshold for a high priority service. The value CZB _th is assigned.

The rate controller 43 compares not only the current RAB information but also the continuous zero bit CZB value and the continuous zero bit threshold CZB _th to determine the rate of reverse traffic.

The transmission unit 44 adjusts the speed of the corresponding traffic by using the value in which the transmission rate of the traffic is adjusted by the transmission rate controller 43 and provides it to the transmitting end 41.

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.

The HDR system proposed in the present invention receives the RAB information from all base stations in the terminal active set (S50).

When at least one base station receives an RAB value of 1 from among the RAB information transmitted from each base station (S51), the continuous zero bit (CZB) value is set to 0 (S52). In this case, as in the prior art, it is determined whether the transmission rate of the current terminal is 9.6 kbps (S53). When the transmission rate exceeds 9.6 kbps, the data is transmitted at a transmission rate of 1/2 of the current transmission rate (S54). In the case of 9.6 kbps or less, the transmission rate is not increased and the current transmission rate is maintained (S55).

However, when all RAB values are received as 0 from all base stations in the active set, the continuous zero bit CZB is increased by 1 (S56), and if the increased value is greater than the continuous zero bit threshold value CZB _th or In the same case, the transmission rate may be increased depending on whether the terminal is currently transmitting a packet.

That is, when the continuous zero bit value CZB is greater than or equal to the continuous zero bit threshold value CZB _th and the current terminal is transmitting a packet, the current transmission rate of the terminal is doubled (S59).

However, when the continuous zero bit value CZB is greater than or equal to the continuous zero bit threshold value CZB _th , and the terminal does not transmit a packet at present, it transmits at a transmission rate of 9.6 kbps or less (S60).

On the other hand, if the continuous zero bit CZB value is smaller than the continuous zero bit threshold CZB _th , the data rate is not increased even if the current reverse traffic channel is not congested. (S55) Therefore, the current data rate of the terminal Keep it.

As described above, according to the present invention, as the priority becomes larger, the continuous zero bit threshold value CZB _th has a relatively small value, and the terminal zero bit threshold value CZB _th is adjusted according to the type and priority of the service. Provide differential services.

In addition, the rate controller adjusts the reverse rate by using the RAB value, the continuous zero bit (CZB) value, and the continuous zero bit threshold value (CZB _th ).

In other words, when congestion occurs in at least one of the base stations in the at least one active set and the RAB becomes 1, it means that the current channel state is not good. Need to be lowered.

On the contrary, if the RAB is 0 in all base stations in the active set, the current channel state is good. However, since the average channel state may not be good, and in this case, a service having a high priority must be provided first, a small continuous zero bit threshold CZB _th is allocated to a service having a high priority.

For example, for the highest priority service, if all received RABs are zero, the transfer rate can be increased immediately. For lower priority services, all received RABs with zero values are received multiple times in succession. Only later can the transmission rate be increased.

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

In particular, the proposed method has no effect on the base station system and has the effect of reducing 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 continuous zero bit counter that receives reverse activity bits (RABs), which are congestion information of the reverse link, from each base station in the active set of the terminal and increases a value when congestion has not occurred for all base stations in the active set; A rate controller which receives a value of the counter and controls a rate of reverse traffic by comparing with a threshold; Apparatus for controlling the transmission rate of the reverse traffic channel of the high speed wireless data communication (HDR) system, characterized in that the transmission unit for adjusting the traffic transmission rate of the terminal according to the controlled transmission rate and transmits to the base station Receiving a reverse activity bit (RAB) for reverse link congestion information from each base station in the active set; Increasing a continuous zero bit (CZB) value when congestion does not occur for all the base stations; High speed wireless data communication comprising the step of controlling the traffic rate of the terminal by comparing not only the reverse activity bit (RAB) value received from the base station but also a continuous zero bit (CZB) value and a preset threshold value. A method of controlling a transmission rate of a reverse traffic channel of a system (HDR). 3. The high speed wireless data communication (HDR) system of claim 2, wherein the threshold is a value assigned according to the type and priority of a service of a terminal and has a relatively small threshold when the priority is high. A method for controlling the transmission rate of a reverse traffic channel of the. 3. The method of claim 2, wherein the transmission rate of the current terminal is maintained when the continuous zero bit (CZB) value is less than a threshold value, and the current zero packet (CZB) value is greater than or equal to a threshold value and the current packet is being transmitted. The transmission rate of the reverse traffic channel of the high speed wireless data communication (HDR) system, characterized by increasing the transmission rate for a new packet to twice the current transmission rate or controlling the current transmission rate of a terminal not currently transmitting the packet to 9.6 kbps or less. Control method. 3. The method of claim 2, wherein congestion occurs in at least one or more base stations due to the reverse activity bit (RAB) information, and the current rate is maintained at a reverse traffic rate of 9.6 kbps or less, and at a terminal traffic rate of more than 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 control at a rate of 1/2 of the transmission rate.