KR20060016024A - Method and apparatus for uplink data rate control in mobile telecommunication system for enhanced uplink dedicated channel - Google Patents

Abstract

The present invention relates to a method and apparatus for effectively managing a measurement noise increase (RoT) value of a base station without increasing downlink signaling overhead when an enhanced uplink dedicated transport channel is used. The base station selects a common signaling method or a dedicated signaling method as scheduling information transmission method as necessary, and transmits transmission format (TF) information in the case of a dedicated signaling method according to the selected signaling method, and transmits in the case of a common signaling method. Send power information. The terminal interprets the rate information according to the signaling scheme. The present invention can reduce the signaling overhead for controlling the transmission rate of the terminal in the enhanced uplink dedicated transport channel.

WCDMA, E-DCH, Node B controlled scheduling, packet transmission, signaling overhead, common signaling, dedicated signaling

Description

Method and apparatus for controlling uplink transmission rate in mobile communication system supporting uplink packet data service {METHOD AND APPARATUS FOR UPLINK DATA RATE CONTROL IN MOBILE TELECOMMUNICATION SYSTEM FOR ENHANCED UPLINK DEDICATED CHANNEL}             

1 illustrates uplink packet transmission over an E-DCH in a typical wireless communication system.

2A and 2B are diagrams illustrating a case where transmission rate information is individually transmitted to all terminals and a case where transmission rate information is integrally transmitted to some terminals.

3 is a diagram illustrating a case of controlling a TF and a case of controlling a transmission power through scheduling information.

4 is a flowchart illustrating a procedure for determining an E-DCH transmission rate by a terminal receiving scheduling information from a base station according to an embodiment of the present invention.

5 is a diagram illustrating a base station transmitter for transmitting scheduling information according to the first embodiment of the present invention.

6 is a diagram illustrating an apparatus for receiving a terminal for receiving scheduling information according to the first embodiment of the present invention.

7 is a diagram illustrating a base station transmitter for receiving scheduling information according to a second embodiment of the present invention.

8 is a diagram illustrating an apparatus for receiving a terminal for receiving scheduling information according to the second embodiment of the present invention.

The present invention relates to a cellular code division multiple access (CDMA) communication system, and more particularly, to an uplink rate control method and apparatus for performing base station control scheduling in an uplink packet data service.

Third generation, based on the European mobile system Global System for Mobile Communications (GSM) and General Packet Radio Services (GPRS), and using Wideband Code Division Multiple Access (CDMA) UMTS (Universal Mobile Telecommunication Service) system, a mobile communication system, is a consistent service that enables mobile phone or computer users to transmit packet-based text, digitized voice or video, and multimedia data at high speeds of 2 Mbps or more anywhere in the world. To provide.

In the UMTS system, an uplink enhanced from a user equipment (UE) to a base station (BS, Node B) in order to further improve the performance of packet transmission in uplink (UL) communication. A transport channel called an enhanced uplink dedicated channel (hereinafter referred to as EUDCH or E-DCH) is used. E-DCH supports Adaptive Modulation and Coding (AMC), Hybrid Automatic Retransmission Request (HARQ), Base Station Control Scheduling, Short TTI (Shorter) to support more stable and high speed data transmission. Transmission Time Interval).

AMC is a technology that determines the modulation and coding method of the data channel according to the channel state between the base station and the terminal, thereby increasing the resource usage efficiency. The combination of modulation scheme and coding scheme is called MCS (Modulation and Coding Scheme), and various MCS levels can be defined according to the supported modulation scheme and coding scheme. AMC adaptively determines the level of the MCS according to the channel state between the terminal and the base station, thereby increasing the resource usage efficiency.

HARQ refers to a technique for retransmitting a packet to compensate for the error packet when an error occurs in an initially transmitted data packet. The complex retransmission technique includes a chase combining technique (hereinafter referred to as CC) that retransmits packets of the same format as the initial transmission when an error occurs, and an incremental increment technique that retransmits packets having a different format than the initial transmission when an error occurs. (Incremental Redundancy: referred to as IR hereinafter).

In case of transmitting data using E-DCH, base station control scheduling determines whether uplink data is transmitted and an upper limit of possible data rate by the base station, and transmits the determined information to the terminal as a scheduling command. Refers to the scheduling command refers to a method of determining and transmitting the data rate of the uplink E-DCH possible.

Short TTIs reduce retransmission latency and consequently enable high system throughput.

1 is a diagram illustrating uplink packet transmission through an E-DCH in a typical wireless communication system. Here, reference numeral 110 denotes a base station supporting the E-DCH, that is, a node B, and reference numerals 101, 102, 103, and 104 denote terminals that use the E-DCH. As shown, the terminals 101 to 104 transmit data to the base station 110 through the E-DCHs 111, 112, 113, and 114, respectively.

The base station 110 informs whether EUDCH data can be transmitted for each UE by using the data buffer status, the request data rate, or the channel state information of the terminals 101 to 104 using the E-DCH, or provides the EUDCH data rate. Perform the scheduling operation to adjust. Scheduling is to increase the performance of the system as a whole, so that the base station far away from the measured noise increase (Noise Rise or Rise over thermal (RoT)) value of the base station does not exceed the target value (e.g., 103, 104 ) Is assigned to a low data rate, and to nearby terminals (eg, 101, 102). The terminals 101 to 104 determine the maximum allowed data rate of the E-DCH data according to the scheduling information, and determine the E-DCH data rate within the maximum allowed data rate to transmit the E-DCH data.                         

Uplink signals transmitted from different terminals in uplink are not orthogonal because they are not kept in synchronization with each other, and thus act as interference. As a result, as the uplink signals received by the base station increase, the amount of interference with respect to the uplink signal of a specific terminal also increases, thereby reducing reception performance. In order to overcome this problem, although the uplink transmission power of the specific terminal may be increased, this again acts as interference to other uplink signals, thereby reducing reception performance. As a result, the total power of the uplink signal that the base station can receive while guaranteeing reception performance is limited. Rise Over Thermal (ROT) represents a radio resource used by the base station in the uplink, and is defined as in Equation 1 below.

I ₀ denotes a power spectral density for the entire reception band of the base station and represents the total amount of uplink signals received by the base station. N ₀ is the thermal noise power spectral density of the base station. Thus, the maximum allowable ROT is the total radio resource that the base station can use on the uplink.

The total ROT of the base station is represented by the sum of inter-cell interference, voice traffic and E-DCH traffic. The base station control scheduling prevents the reception ROT from increasing beyond the target ROT by not allowing the other terminal to have a high data rate when allowing a specific data rate.                         

In case of base station control scheduling, the overhead of downlink signaling due to signaling of rate information should be considered when there are many terminals performing E-DCH service in one cell. For example, if the number of terminals is very large, the base station consumes downlink transmission power for transmitting the rate information, or many downlink channel codes are required for transmitting the rate information. This may cause a problem of reducing downlink capacity in the entire cell. Therefore, there is a need for a technique for reducing downlink signaling overhead in transmitting rate information for base station control scheduling.

An object of the present invention, which was devised to solve the problems of the prior art operating as described above, requires scheduling information for controlling a transmission rate of a terminal by a base station in a mobile communication system supporting an enhanced uplink dedicated transport channel. Accordingly, a method and apparatus for selecting and transmitting a dedicated signaling scheme and a common signaling scheme are provided.

It is still another object of the present invention to include a transmission format corresponding to a transmission rate of a terminal in the scheduling information when using a dedicated signaling method in transmitting scheduling information for controlling a transmission rate of the terminal. The present invention provides a method and apparatus for including a transmission power value corresponding to a transmission rate of a terminal in scheduling information.                         

In order to achieve the above object, an embodiment of the present invention provides a method for transmitting scheduling information for scheduling an uplink packet data service from a user terminal from a base station to the user terminal.

Allocating a transmission rate for the uplink packet data service;

Selecting a signaling method for notifying the transmission rate according to the allocated transmission rate as one of a dedicated signaling method and a common signaling method;

And generating and transmitting dedicated rate information or shared rate information indicating the determined rate according to the selected signaling scheme.

In another embodiment of the present invention, in the method for receiving scheduling information for scheduling uplink packet data service from a user terminal in the user terminal,

Receiving scheduling information indicating a transmission rate allocated for the uplink packet data service;

Determining whether the scheduling information is dedicated scheduling information according to a dedicated signaling scheme or public signaling information according to a common signaling scheme;

If the scheduling information is the dedicated scheduling information, the transmission format corresponding to the dedicated scheduling information is determined as the maximum allowable transmission format of the user terminal, and a transmission rate for the uplink packet data service is determined within the maximum allowable transmission format. Process,                         

If the scheduling information is the common signaling information, the transmission power corresponding to the common scheduling information is determined as the maximum allowable transmission power of the user terminal, and a transmission rate for the uplink packet data service is determined within the maximum allowable transmission power. Characterized in that it comprises a process.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

In the present specification, embodiments of the present invention will be described in detail for an enhanced uplink dedicated transport channel (E-DCH) of a UMTS communication system.

Base station control scheduling in the E-DCH is a technique for improving the system yield and coverage by allowing the base station to efficiently control the uplink RoT. To this end, the base station controls the E-DCH data rates of the terminals through base station control scheduling. The E-DCH data rate of the UE is mapped to an E-DCH transport format (TF) or an E-DCH transmission power. The E-DCH TF set (TF Set: TFS) of each terminal controlled by the base station may be set differently according to the type of service required by each terminal. For example, a terminal using a game service and a terminal using a file transfer protocol (FTP) service may have different sets of TFs required by each service.

In addition, as the data rate of the E-DCH is higher, the terminal requires more transmission power for the E-DCH. Herein, the transmission power of the E-DCH is a power offset of the enhanced dedicated physical data channel (hereinafter referred to as E-DPDCH) compared to the dedicated physical control channel (hereinafter referred to as DPCCH). PO). Here, the DPCCH is a physical channel which is a reference for setting the transmission power of the physical channels, and the E-DPDCH is a physical channel to which the E-DCH is mapped.

A base station control scheduling method for controlling a transmission rate of a terminal includes the following method. One is rate scheduling for increasing or decreasing the data rate of the terminal, and the other is time and rate scheduling for controlling the transmission and reception times of the terminal together with the data rate of the terminal. There is also a method of combining rate scheduling and time rate scheduling.

In the rate scheduling scheme, the UE can transmit data at each transmission time interval (hereinafter referred to as TTI) and the base station informs all UEs of the transmission rate information at every TTI since the data transmission rate is controlled by the base station. . In this case, if the absolute value of the data rate is reported, the signaling overhead is too large, so the base station signals (ie, transmits) rate permit information (ie, called RG) that informs the increase or decrease of the rate instead of the absolute value of the rate. do. In general, the rate allowance information is 1-bit information indicating the increase / decrease / maintenance of the rate. In this case, the amount of change in the transmission rate that can be controlled by the base station at one moment for one terminal is limited. In other words, even if the terminal requires a very high transmission rate, the base station incrementally increases the transmission rate of the terminal through multiple signaling. Therefore, the time delay for obtaining the desired transmission rate is large.

In the time rate scheduling scheme, the UE transmits E-DCH traffic according to the rate information received from the base station, and does not transmit the E-DCH traffic when the rate information is not received. To this end, the base station informs the absolute value of the rate every time. Since the base station uses the absolute rate, it is possible to assign a random rate among the possible rates at every transmission point to the terminal. For example, if the terminal supports a transmission rate of 8kbps ~ 1Mbps, the base station may allocate 8kbp at one transmission time and 1Mbps at the next transmission time. Alternatively, the E-DCH transmission is blocked by not transmitting the rate information. Unlike rate scheduling, the rate scheduling can change up to the maximum data rate through one scheduling operation, thereby reducing time delay due to scheduling.

On the other hand, in transmitting the scheduling information (ie, rate information) for controlling the E-DCH rate to the terminal, the base station may consider a dedicated signaling scheme and a common signaling scheme. The dedicated signaling method basically signals transmission rate allowance information or information on transmission time and allowable transmission rate for each terminal, and the base station determines the priority of each terminal or the quality of service (QoS) of data to be serviced, In other words, scheduling is performed according to priority. On the other hand, the common signaling method is that a base station performs scheduling in common to terminals in a cell with little signaling overhead.

In the base station control scheduling, the number of terminals to which the base station should transmit scheduling information greatly increases in the following cases.

When the RoT level is increased due to a sudden increase in the amount of interference in the cell, it is necessary to temporarily reduce the transmission rate of all terminals in the cell.

When reducing the transmission rate of many other terminals at a time in order to service a high transmission rate to a specific terminal. In this case, the specific terminal refers to a terminal having a higher priority than other terminals or having a large amount of data waiting to be transmitted.

When the RoT level of the cell is sufficient, it is possible to increase the transmission rates of many terminals at once

As described above, when the number of terminals to which the base station needs to transmit scheduling information increases to a predetermined number or more, downlink overhead due to signaling of scheduling information should be considered. That is, a method for reducing downlink transmission power and downlink code channel for downlink signaling is needed. Accordingly, the base station uses a dedicated signaling method when scheduling each terminal individually in accordance with a situation, and uses common scheduling when uniformly performing common scheduling among terminals in a cell with less signaling overhead. Use the method.

2A and 2B compare the dedicated signaling scheme for individually transmitting scheduling information to all terminals and the common signaling scheme for integrally transmitting scheduling information to some terminals.

Referring to FIG. 2A, the base station 201 transmits scheduling information through a shared control channel (EU-SCCH) 202 in order to schedule an E-DCH service. In this case, since there are five terminals UE1 203 to UE5 207 performing the E-DCH service, the EU-SCCH 202 may have five separate channels having unique channel codes or time intervals. To EU-SCCH5. In every scheduling period, the base station 210 determines the transmission rates for the UE1 203 to the UE5 207 and transmits scheduling information including the respective transmission rates on the individual channels EU-SCCH1 to EU-SCCH5. Therefore, up to five channels are required for transmitting each scheduling information at each transmission point.

If a UE having a high priority, for example, UE5 207 requires a high data rate, the base station 210 assigns a high data rate to the UE5 207, but the other allowable RoT resources are limited in the cell. UEs 203 to UE4 206 are commonly assigned low data rates. In this case, when the scheduling information transmitted to the terminals UE1 203 to UE4 206 are all the same, a common signaling scheme is used. Signaling in this case is shown in Figure 2b.                     

Referring to FIG. 2B, the base station 210 allocates a high transmission rate to the UE5 207 having a high priority through the dedicated signaling channel EU-SCCH5 209 and to the remaining UE1 203 to UE4 206. Allocate low data rates on the common signaling channel EU-SCCH 208 collectively. In this way, when the transmission rate is collectively informed, the number of channels to be transmitted by the base station 210 is reduced to two compared to five of FIG. 2A.

When the base station controls the transmission rate of the terminal in consideration of the RoT situation in the cell, the base station may control the E-DCH TF of the terminal and may control the E-DCH transmission power. As described above, since the E-DCH TF and the E-DCH transmission power have a one-to-one mapping relationship, there is basically no significant difference between the two methods. However, since the E-DCH TF set may be different according to the type of service to be used for each terminal, in this case, the base station uniformly applies E-DCH transmission for all terminals to apply a common signaling method. Control power. That is, in the common signaling method, the E-DCH transmission power of the UE to be controlled by the BS is signaled so that the UE determines the maximum E-DCH transmission rate of the UE within a range not exceeding the E-DCH transmission power signaled by the BS. Done.

A method of controlling the E-DCH TF and a method of controlling the E-DCH transmission power according to the signaling scheme of the E-DCH scheduling information will be described with reference to FIG. 3.

In FIG. 3, reference numerals 301 to 308 indicate the E-DCH transmission power of the UE in the order of low to high, and indicate a PO (power offset) value of the E-DPDCH for the DPCCH. The power offset values 301 to 308 are mapped one-to-one with a TF for an E-DCH or a transmission rate for an E-DCH. Here, for convenience of description, two terminals UE # 1 and UE # 2 are considered, and each terminal configures a different TF set for different services. That is, UE1 (UE # 1) has a TF set 310 including TF0 311 to TF3 314, and UE2 has a TF set including TF0 (reference numeral 321) to TF3 324. Has 320.

First, a method of controlling E-DCH TFs of UEs through a dedicated signaling method will be described. As described above, since the dedicated signaling method is a method in which the base station individually controls the transmission rate of each terminal, it is possible to directly control an individual TF set of each terminal that is already set between the base station and each terminal. In FIG. 3, if the current terminal 1 is the TF3 314 and the terminal 2 is the maximum TF that the TF1 322 can transmit for the E-DCH, each terminal is the E-DCH within the maximum allowed TFs 314 and 322. The transmission rate is determined to transmit the E-DCH data. In order for the base station to lower the TF of the terminal 1 to the TF2 313 and increase the TF of the terminal 2 to the TF3 324, in the case of a dedicated signaling scheme, the base station signals each TF to be changed to each terminal.

Next, a method of controlling E-DCH TFs of UEs through a common signaling method will be described. When the base station wants to adjust the transmission rates of the terminal 1 and the terminal 2 collectively, it is advantageous in terms of signaling overhead to control through a common signaling scheme rather than individually through a dedicated signaling scheme. Since the E-DCH TF sets of UE 1 and UE 2 are set differently, in order to control transmission rates of UEs through a common signaling method, the base station preferably controls E-DCH transmission powers that can be recognized by each UE in common. Do. If the maximum TF currently transmitable is TF3 314 for UE 1 and TF1 322 for UE 2, the base station collectively allows E-DCH transmission power of UEs to the level of 304. The following three methods are used as common signaling methods.

[Common Signaling Method 1]

According to the common signaling method 1, the base station informs the terminal of the E-DCH transmission power of the terminal to be controlled by a common signaling method, and the terminal transmits the E-DCH transmission power of the terminal within the range not exceeding the E-DCH transmission power signaled by the base station. -DCH maximum rate is determined. Referring to FIG. 3, the base station first signals the power offset value corresponding to the reference number 304 to the terminal 1 and the terminal 2 through the common signaling information. Terminal 1 receives the common signaling information to find a TF corresponding to the transmission power within the TF set 310 does not exceed the power offset value 304, and accordingly the TF1 312 to a new E-DCH It will be set to the maximum TF that can be sent. Similarly, the terminal 2 receives the common signaling information to find a TF corresponding to the transmission power within the TF set 320 that does not exceed the power offset value 304, and thus, the current TF set 320 is present. It is determined that E-DCH data cannot be transmitted within.

[Common Signaling Method 2]

According to the common signaling method 2, the terminals configure a new common TF set for applying the common signaling, and the base station notifies the terminal of the transmission power value corresponding to each TF in the common TF set by using the common signaling. do. Then, each UE compares the reported transmit power value with the E-DCH transmit power value and sets the maximum TF corresponding to the transmit power not exceeding this to be the maximum TF transmittable for the E-DCH. The common TF set for common signaling is configured in consideration of the minimum E-DCH transmission rate, the maximum transmission rate of E-DCH, and the number of TFs or signaling bits required among UEs supporting E-DCH in a cell. . In other cases, the terminals acquire the common TF set through signaling when configuring the E-DCH.

Referring to FIG. 3, the minimum TF 311 of the terminal 1 becomes the minimum TF 331 of the common TF set 330, and the maximum TF 324 of the terminal 2 corresponds to the maximum TF of the common TF set 330 ( 334, a common TF set 330 having four levels of TFs 331 to 334 is configured similarly to the TF sets 310 and 320 for dedicated signaling of the terminal 1 and the terminal 2. When the base station collectively signals the power offset value corresponding to the reference number 304 through the common signaling information, the terminals compare the power offset value 304 of the common signaling information with the common TF set 330 to obtain a new TF. You will find it. That is, the terminal 1 and the terminal 2 is the maximum TF that can transmit TF0 331, which is a TF corresponding to the transmission power that does not exceed the power offset value 304, in the common TF set 330 for a new E-DCH. Set it.

Since the common signaling method 2 uses a common TF set, the base station may transmit the TF values collectively through the common signaling information instead of signaling the power offset value.                     

[Public signaling method 3]

In common signaling method 3, terminals configure common TF sets for each group for common signaling. Here, the common TF sets are grouped by service type or data rate to be controlled in consideration of the minimum and maximum data rates and the number of TFs or signaling bits required. That is, various terminals using the E-DCH service in the cell are grouped by service type or by data rate and scheduled by each group through common signaling. In other cases, the terminals acquire the common TF set through signaling when configuring the E-DCH.

Referring to FIG. 3, terminal 1 is classified into group 1 and terminal 2 is classified into group 2 for common signaling. The common TF set 340 of the group 1 is configured by reconfiguring the TF to further control the TF having a high data rate in the TF set 310 of the terminal 1, the public TF set 350 of the group 2 is The TF set 320 is configured by reconfiguring the TF to more finely control the TF having a high transmission rate.

As an example, the base station collectively allows the E-DCH transmit power of the group 1 to the power offset value of the reference number 304 through each common signaling information, and collectively allows the E-DCH transmit power of the group 2 to the reference number 306. Allow up to power offset values. Then, the UE belonging to each group finds a new TF by comparing the common signaling information of each group with the common TF set of the group to which it belongs. That is, UE1 transmits TF1 342, which is a TF corresponding to the transmission power not exceeding the power offset value 304, in the common TF set 340 of group 1 as the maximum TF that can be transmitted for a new E-DCH. UE 2 transmits a maximum TF capable of transmitting TF0 351, which is a TF corresponding to a transmission power not exceeding the power offset value 306, in the common TF set 350 of group 2 for a new E-DCH. Set to.

Since the common signaling method 3 also uses the common TF set, the base station may transmit the TF value for each group through the common signaling information instead of signaling the power offset value.

4 is a flowchart illustrating a procedure of determining an E-DCH transmission rate by a terminal receiving scheduling information from a base station according to an embodiment of the present invention.

Referring to FIG. 4, in step 401, a terminal receives scheduling information from a base station. In step 402, the terminal determines whether the scheduling information is dedicated signaling or public signaling. In this case, the classification of the dedicated signaling and the common signaling is performed by a code channel in which the scheduling information is received, an identifier (UE ID) of a terminal, and radio resource control (RRC) signaling.

For example, the base station transmits the scheduling information using a code channel for dedicated signaling and a code channel for common signaling, respectively. As another example, using the dedicated and common terminal identifiers, without including the code channel for the dedicated signaling and the code channel for the public signaling, by including the individual terminal identifier in the signaling information to perform the dedicated signaling for the individual terminal, Common signaling is performed by including a common terminal identifier shared by several terminals in the signaling information. The common identifier notifies separately when the UE initially sets or resets the E-DCH. In another case, the base station notifies the terminal of signaling indication information indicating dedicated signaling / public signaling through RRC signaling. When the scheduling information is received, if both the dedicated signaling and the common signaling exist, priority is given to the dedicated signaling so as to be recognized as the dedicated signaling.

If it is determined in step 402 that the dedicated signaling, in step 403 the signaling information is interpreted as a dedicated signaling value to recognize the E-DCH maximum allowable TF available to the terminal. Thereafter, in step 404, the UE determines the E-DCH transmission rate in consideration of the amount of E-DCH data in the buffer, the currently available transmission power, the currently available TF set, the maximum allowed TF of the E-DCH, and the capacity of the UE. do. On the other hand, if it is determined in step 402 that the common signaling, the terminal in step 405 interprets the signaling information as a common signaling value to recognize the maximum allowable transmission power or TF value E-DCH available to the terminal. Thereafter, in step 406, the UE determines the E-DCH transmission rate in consideration of the amount of E-DCH data in the buffer, the currently available transmission power, the currently available TF set, the maximum allowable TF of the E-DCH, and the capacity of the UE.

Next, a method of setting scheduling information to E-DCH TF or E-DCH transmission power according to the signaling format of scheduling information proposed by the present invention is a time and rate scheduling method and a rate scheduling method. It will be described specific embodiments applied to.

<< first embodiment >>                     

This first embodiment uses a time rate scheduling scheme.

In a system for controlling uplink transmission rate of a terminal by transmitting absolute value information of an allocated transmission rate, a Radio Network Controller (RNC) for controlling a wireless connection of terminals is assigned to a terminal by a common UE-ID. And dedicated UE-IDs, and the base station transmits transmission rate information using a dedicated identifier or a transmission rate information using a common identifier to a specific terminal as needed. For example, when a base station wants to transmit individual scheduling information according to a priority of each terminal or QoS of data to be serviced according to a situation, a dedicated signaling method using a dedicated identifier is used, and a signaling in a cell has a small signaling overhead. When uniformly transmitting common scheduling information to terminals, a common scheduling method using a common identifier is used.

In the first embodiment, the scheduling assignment information (hereinafter, referred to as SA) transmitted by the base station to the terminal includes E-DCH rate information allocated to the terminal and is cyclic redundancy masked with identifier information for identifying the terminal. Check) is sent along with the information. The terminal decodes the scheduling allocation (SA) information normally without a CRC error only when the CRC information masked with the identifier information matches the identifier given to the terminal. When the dedicated scheduling method is applied, the SA information has a TF value indicating the absolute value information of the E-DCH transmission rate allocated to the terminal. When the common scheduling method is applied, the SA information is the absolute value of the E-DCH transmission rate allocated to the terminal. E-DCH transmit power offset value or TF value indicating information.                     

An operation of determining, by the terminal, transmission rate by receiving scheduling allocation (SA) information according to the first embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 4, in step 401, a terminal receives scheduling information including scheduling allocation information and a CRC masked by a terminal identifier from a base station every scheduling period. In step 402, the terminal detects the masked CRC from the scheduling information, performs reverse masking with the dedicated identifier and the common identifier assigned to the terminal, and performs a CRC check. At this time, if it is determined that there is no CRC error after CRC reverse masking with the dedicated identifier, it is determined as dedicated signaling. If it is determined that there is no CRC error after CRC reverse masking with the public identifier, it is determined as public signaling. When both CRC reverse masking with the dedicated identifier and CRC reverse masking with the common identifier are determined that there is no CRC error, the terminal gives priority to the dedicated identifier and recognizes it as dedicated signaling. In both cases, if a CRC error occurs, the UE waits to receive new scheduling information until the next scheduling period.

If it is determined in step 402 that the dedicated signaling, in step 403 the scheduling allocation information is interpreted to determine the maximum allowable TF E-DCH allowed by the terminal. Thereafter, in step 404, the UE determines the E-DCH transmission rate in consideration of the maximum allowed TF of the E-DCH, the amount of E-DCH data of the UE buffer, the currently available transmission power, the currently available TF set, and the capacity of the UE. . If it is determined in step 402 that the common signaling, the terminal in step 405 interprets the scheduling assignment information to recognize the maximum allowable transmission power or TF value E-DCH available to the terminal. Thereafter, in step 406, the UE determines the E-DCH transmission rate in consideration of the maximum allowable transmission power of the E-DCH, the amount of E-DCH data of the UE buffer, the currently available transmission power, the currently available TF set, and the capacity of the UE. do.

5 shows an apparatus for transmitting a base station for transmitting scheduling information according to the first embodiment of the present invention. Here, the base station transmitter transmits EU-SCCH data.

Referring to FIG. 5, the base station scheduler 502 allocates a transmission rate to a terminal to perform an E-DCH service. The scheduler 502 allocates the transmission rate of the terminal based on the buffer state and the power state reported by the terminal, and the RoT level of the cell, and also determines a signaling method together with the transmission rate, and the terminal according to the determined signaling method. An identifier (UE-ID), that is, a dedicated identifier or a public identifier, is passed to the CRC generator 504. CRC generator 504 generates a CRC masked with the passed dedicated or public identifier. The rate information generator 506 generates rate information according to the assigned rate, and when the dedicated scheduling method is applied according to the scheduling method determined by the scheduler 502, the rate information generator 506 generates a TF value as the rate information, and performs common scheduling. When the scheme is applied, a transmit power value (ie, a power offset value) or a TF value is generated as the rate information.

CRC adder 508 adds the masked CRC to the rate information to generate scheduling information. The masked CRC is also called a UE-specific CRC (UE-specific CRC) because it includes a dedicated terminal identifier of the terminal. The scheduling information including the masked CRC and the rate information is encoded by the encoder 510 and then modulated by the modulator 512 to increase reliability, and spreader 514 by the channel of the EU-SCCH. It is multiplied by a code (Channelization Code) C _{e, c} to become EU-SCCH data. The multiplexer 516 multiplexes and transmits the EU-SCCH data with data of other channels.

6 illustrates a receiving apparatus of a terminal for receiving scheduling information according to the first embodiment of the present invention. Here, the receiver of the terminal receives EU-SCCH data.

Referring to FIG. 6, the received signal is despread by multiplying by the despreader 612 with the channel codes C _{e and c} of the EU-SCCH, demodulated by the demodulator 610, and then decoded by the decoder 608. Input to the CRC detector 606. The CRC detector 606 extracts the masked CRC from the decoded data and delivers it to the CRC checker 614. The CRC checker 614 receives both a dedicated identifier and a public identifier of the UE from the E-DCH controller 602, performs a CRC check by reverse masking the masked CRC with the dedicated identifier first in every scheduling period, If an error occurs as a result of the CRC check, a CRC check is performed by reverse masking the masked CRC with a common identifier. The CRC checker 614 determines the CRC result by the terminal identifiers and transmits the CRC result to the CRC detector 606.

The CRC detector 606 transmits, to the rate information determiner 604, the rate information other than the CRC of the decoded data to the rate information determiner 604 when the CRC check succeeds with any one terminal identifier. Discard. The rate information determiner 604 interprets the rate information to determine the maximum allowable E-DCH TF when the rate information is a dedicated signaled value, and interprets the rate information to determine the maximum allowed when the rate information is a publicly signaled value. Determine the E-DCH transmit power or TF value. The E-DCH controller 602 determines in the rate information determiner 604 in consideration of the amount of E-DCH data in the buffer, the currently available transmission power, and the signaling scheme, in consideration of the currently available TF set and the capacity of the UE. The E-DCH transmission rate is determined within a range not exceeding the specified value.

<< 2nd Example >>

This second embodiment uses a rate scheduling scheme.

In a system for controlling an uplink transmission rate of a terminal by transmitting a rate allowance information that increases, decreases, or keeps up a transmission rate, a radio network controller (RNC) transmits a common code and a dedicated code to the terminals. The base station transmits the transmission rate information using a dedicated code or a transmission rate information using a common code as necessary. Here, the common code and the dedicated codes mean orthogonal codes for signal spreading. For example, when a base station wants to transmit individual scheduling information according to a priority of each terminal or QoS of data to be serviced according to a situation, a dedicated signaling method using a dedicated code is used, and the signaling is performed in a cell with a small signaling overhead. When uniformly transmitting common scheduling information to terminals, a common scheduling method using a common code is used.                     

In this case, when the dedicated scheduling scheme is applied, the scheduling information has a rate allowance (RG) information for increasing (UP), decreasing (DOWN), or maintaining (KEEP) the E-DCH TF index of the UE, and scheduling if the common scheduling scheme is applied. The information has a rate allowed (RG) information for increasing (UP), decreasing (DOWN) or maintaining (KEEP) the E-DCH transmission power or TF value of the terminal.

In addition, in order to set the authority of the dedicated scheduling and the common scheduling differently, the common scheduling information has (DOWN), DON'T CARE or decreases (DOWN) and ignores (DON'T) the transmission power or the TF value. CARE) and MARGINAL DOWN. In this way, different authority of dedicated scheduling and common scheduling may be useful when E-DCH scheduling is performed by distinguishing between optimal scheduling base station and non-optimal scheduling base station. However, the subject matter of the present invention is irrelevant to this, and further description thereof will be omitted.

The amount by which the E-DCH transmit power or TF value increases (UP) or decreases (UP) is promised to be a predetermined constant value, so that the E-DCH transmit power or TF value is equal to the same amount among UEs receiving common signaling. Increase or decrease.

In assigning orthogonal codes to terminals, the radio network controller allocates dedicated codes and common codes through higher layer signaling so that the terminal can receive rate tolerance information. At this time, the radio network controller allocates a common code and a dedicated code to all terminals of all cells, or allocates a dedicated code and a common code to a group of terminals classified according to a service type or a transmission rate. Rate allowance information for the terminal is spread to the assigned orthogonal code. The terminal determines a correlation value between the received signal and the assigned orthogonal code and determines whether the received signal includes a rate allowance information for itself.

The base station determines the rate allowance (RG) information and the signaling scheme of the terminal communicating for the E-DCH service at every scheduling time. The criteria for determining the signaling scheme is determined according to the system design and implementation. In one embodiment, the base station simply determines RG information, which takes up a large portion of increase / decrease / maintenance, by using a common signaling method. In another embodiment, the base station selects a common signaling scheme to increase or decrease transmission rates of a plurality of terminals in a cell, and selects a dedicated signaling scheme for the remaining terminals. When the RG information and the signaling scheme are determined, the base station spreads and transmits the RG information in an orthogonal code according to the determined signaling scheme.

According to the second embodiment of the present invention, an operation of determining a transmission rate by receiving a transmission rate grant (RG) information will be described with reference to FIG. 4 mentioned above.

Referring to FIG. 4, in step 401, the UE receives data spread with an orthogonal code in every scheduling period. In step 402, the UE detects the dedicated RG information by despreading the spread data using the dedicated orthogonal code. The dedicated RG information may have one of the values of + 1/0 / -1. In the case of dedicated signaling according to a signaling scheme, the values mean increase (UP) / keep (KEEP) / decrease (DOWN). In other cases, the values + 1/0 / -1 of the dedicated RG information mean increase (UP) / receive / decrease (DOWN) the common signaling information.                     

When RF information is obtained by performing despreading with a dedicated orthogonal code in step 402, the UE increases, maintains or decreases the maximum allowable TF index of the current E-DCH by a predetermined value according to the RG information in step 403. Thereafter, in step 404, the UE indicates the TF indicated by the E-DCH maximum allowed TF index, the amount of E-DCH data in the buffer, the currently available transmission power, the currently available TF set, the maximum allowed TF in the E-DCH, the capacity of the UE In consideration of this, the E-DCH transmission rate is determined. On the other hand, if the despreading is performed using the dedicated orthogonal code in step 402 and fails to obtain valid (that is, interpretable) information, the terminal despreads using the common orthogonal code.

As another embodiment mentioned above, when the value '0' of the dedicated RG information means receiving public signaling information, and the dedicated RG information is '0', the UE spreads the spread using a common orthogonal code in step 402. The shared RG information is detected again by despreading the acquired data. When the common RG information is common signaling, the values mean UP, KEEP, and DOWN, respectively. In step 405, the UE increases, decreases, or maintains the current E-DCH maximum allowable transmit power by a predetermined value according to the common RG information. That is, the terminal increases the maximum allowable transmit power when the common RG information interpreted using the common orthogonal code is +1, decreases it when -1, and maintains 0. Thereafter, in step 406, the UE determines the E-DCH transmission rate in consideration of the maximum allowable transmit power of the E-DCH, the amount of E-DCH data in the buffer, the currently available transmit power, the currently available TF set, and the capacity of the UE.

7 illustrates a transmission extension value of a base station transmitting scheduling information according to the second embodiment of the present invention. Here, the base station transmitter transmits EU-SCCH data.

Referring to FIG. 7, the scheduler 702 allocates a transmission rate to a terminal to perform an E-DCH service. The scheduler 702 allocates the transmission rate of the terminal using the buffer state and the power state reported by the terminal, and the RoT level of the cell, and determines a signaling scheme according to the allocated transmission rate.

The RG information generator 704 operates according to the determined signaling scheme. First, when determined as a dedicated signaling scheme, the RG information generator 704 compares a TF index indicating a transmission rate allocated by the scheduler 702 with a TF index indicating a current maximum allowable transmission rate of the terminal, and increases +1 (increment). Generate dedicated RG information having a value of 0 (receive maintenance or common signaling information) or -1 (decrement). Or, if it is determined by the common signaling scheme, the RG information generator 704 compares the E-DCH transmission power indicating the transmission rate allocated by the scheduler 702 with the transmission power indicating the current maximum allowable transmission rate of the terminal, and +1. Generate public RG information with a value of (increment), 0 (maintain) or -1 (decrement).

The RG information thus generated is modulated by the modulator 706. Meanwhile, the RG code controller 714 selects an orthogonal code for the RG information according to the signaling method determined by the scheduler 702. That is, the orthogonal code is selected as a common orthogonal code in the case of a common signaling scheme and a dedicated orthogonal code in the case of a dedicated signaling scheme.

The modulated RG information is multiplied by the selected orthogonal code and spread by the spreader 708, and then multiplied by the channel codes Ce and c of the EU-SCCH to become EU-SCCH data. The multiplexer 712 multiplexes and transmits the EU-SCCH data with data of other channels.

8 illustrates a receiving apparatus of a terminal for receiving scheduling information according to the second embodiment of the present invention. Here, the receiver of the terminal receives EU-SCCH data.

Referring to FIG. 8, the received signal is multiplied by the channel codes Ce and c of the EU-SCCH by the despreader 810 to distinguish the channels. The RG code controller 812 receives the dedicated orthogonal code and the common orthogonal code of the terminal from the E-DCH controller 802, and sets the dedicated orthogonal code to the despreader 808 first in every scheduling period. The channel separated signal is multiplied by the dedicated orthogonal code by the despreader 808 and then demodulated by the demodulator 806 and input to the RG information identifier 804.

The RG information identifier 804 transmits an increase, maintain or decrease command according to the RG information included in the demodulated data to the E-DCH controller 802. The E-DCH controller 802 increases, maintains or decreases the TF index indicating the current maximum allowable transmission rate according to the increase, maintain or decrease command, and then the TF and terminal buffer indicated by the E-DCH maximum allowable TF index. The E-DCH transmission rate is determined in consideration of the amount of E-DCH data, the currently available transmission power, the currently available TF set, the maximum allowable TF of the E-DCH, and the capacity of the UE.

On the other hand, if the RG information means UP / KEEP / DOWN, and the RG information can not be identified with the dedicated orthogonal code, the RG information identifier 804 is an RG code. Request controller 812 to set the common orthogonal code. In another embodiment, when the RG information means UP / public signaling information reception / decrease (KEEP), the RG information included in the demodulated data is identified with the dedicated orthogonal code and its value is changed. If 'receive public signaling information', the RG information identifier 804 requests the RG code controller 812 to set the common orthogonal code.

The RG code controller 812 sets a common orthogonal code to the despreader 808 according to the request. The channel separated signal is then multiplied by the common orthogonal code by the despreader 808 and demodulated by the demodulator 806 and input to the RG information identifier 804.

The RG information identifier 804 transmits an increase, decrease or maintain command according to the RG code included in the data despread and demodulated by the common orthogonal code to the E-DCH controller 802. The E-DCH controller 802 increases or decreases or maintains the E-DCH maximum allowable transmit power indicating the current maximum allowable transmit rate according to the increase, decrease or maintain command, and then adjust the adjusted E-DCH maximum allowable transmit. The E-DCH transmission rate is determined in consideration of the power, the amount of E-DCH data in the terminal buffer, the currently available transmission power, the currently available TF set, the maximum allowable TF of the E-DCH, and the capacity of the terminal.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention.

That is, in the first embodiment of the present invention described above, scheduling is performed using a dedicated identifier and a public identifier in time rate scheduling, and in the second embodiment, scheduling is performed using a dedicated orthogonal code and a common orthogonal code in rate scheduling. Was performed. However, those skilled in the art will appreciate that another embodiment of performing scheduling using dedicated orthogonal code and common orthogonal code in time rate scheduling, and scheduling using dedicated identifier and common identifier in rate scheduling It is a matter of course that other embodiments can be easily implemented. In addition, even when time rate scheduling and rate scheduling are used at the same time, those skilled in the art can implement the scheduling method proposed by the present invention with reference to the first and second embodiments.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

According to the present invention, when an enhanced uplink dedicated transport channel is used, signaling overhead can be reduced by selecting and transmitting scheduling information for controlling a transmission rate of a terminal from a dedicated signaling scheme and a common signaling scheme as needed. By using the dedicated signaling scheme, the maximum allowed TF of the TF set set when the E-DCH is set is controlled to prevent inconsistency of the E-DCH maximum allowable transmission rate that may occur in generating / interpreting signaling values between the transmitting and receiving end. Can be. In addition, the common signaling scheme allows a plurality of terminals to interpret common signaling at the same time by controlling the transmission power, thereby increasing the efficiency of the base station signaling the scheduling information.

Claims (25)

A method for transmitting scheduling information for scheduling an uplink packet data service from a user terminal to a user terminal, the method comprising: Allocating a transmission rate for the uplink packet data service; Selecting a signaling method for notifying the transmission rate according to the allocated transmission rate as one of a dedicated signaling method and a common signaling method; And generating and transmitting the dedicated rate information or the common rate information indicating the determined rate according to the selected signaling method. The method of claim 1, wherein the selecting process comprises: Selecting the dedicated signaling scheme when individually controlling the transmission rates of the terminals performing the uplink packet data service, and selecting the common signaling scheme when collectively controlling the transmission rates of the predetermined number or more terminals Characterized in that the method. The method of claim 1, wherein the dedicated rate information, And a transmission format index of a transmission format indicating the transmission rate allocated for the uplink packet data service. The method of claim 1, wherein the dedicated rate information, And transmission rate allowance information for increasing, decreasing or maintaining a transmission format index of a transmission format for the uplink packet data service according to the transmission rate allocated for the uplink packet data service. The method of claim 1, wherein the common rate information, And a power offset value indicating a transmission power for the uplink packet data service. The method of claim 1, wherein the common rate information, And transmission rate allowance information for increasing, decreasing or maintaining a power offset value indicating a transmission power for the uplink packet data service by a predetermined value. The method of claim 1, wherein the transmitting of the When the dedicated signaling scheme is selected, an error correction code masked with the dedicated identifier assigned to the user terminal is generated, and the error correction code masked with the dedicated identifier is added to the dedicated rate information for transmission. Way. The method of claim 7, wherein the transmitting step, And generating an error correction code masked with a predetermined public identifier when the public signaling scheme is selected, and adding the error correction code masked with the public identifier to the public rate information. The method of claim 1, wherein the transmitting of the And if the dedicated signaling scheme is selected, spreading and transmitting the dedicated rate information to a dedicated orthogonal code assigned to the user terminal. The method of claim 9, wherein the transmitting step, And if the common signaling method is selected, spreading the common data rate information to a predetermined common orthogonal code and transmitting the same. A method for receiving scheduling information for scheduling an uplink packet data service from a user terminal in the user terminal, the method comprising: Receiving scheduling information indicating a transmission rate allocated for the uplink packet data service; Determining whether the scheduling information is dedicated scheduling information according to a dedicated signaling scheme or public signaling information according to a common signaling scheme; If the scheduling information is the dedicated scheduling information, the transmission format corresponding to the dedicated scheduling information is determined as the maximum allowable transmission format of the user terminal, and a transmission rate for the uplink packet data service is determined within the maximum allowable transmission format. Process, If the scheduling information is the common signaling information, the transmission power corresponding to the common scheduling information is determined as the maximum allowable transmission power of the user terminal, and a transmission rate for the uplink packet data service is determined within the maximum allowable transmission power. The method comprising the step of. The method of claim 11, wherein the dedicated scheduling information, And a transmission format index of a transmission format indicating the transmission rate allocated for the uplink packet data service. The method of claim 11, wherein the dedicated scheduling information, And transmission rate allowance information for increasing, decreasing or maintaining a transmission format index of a transmission format for the uplink packet data service according to the transmission rate allocated for the uplink packet data service. The method of claim 11, wherein the common scheduling information, And a power offset value indicating a transmission power for the uplink packet data service. The method of claim 11, wherein the common scheduling information, And transmission rate allowance information for increasing, decreasing or maintaining a power offset value indicating a transmission power for the uplink packet data service by a predetermined value. The method of claim 14 or 15, wherein the determining process, In the set of transmission formats for the uplink packet data service owned by the user terminal, a transmission format corresponding to a transmission power not exceeding the transmission power corresponding to the common scheduling information is selected, and according to the selected transmission format. Determining the transmission rate. The method of claim 14 or 15, wherein the determining process, Selecting a transmission format corresponding to a transmission power not exceeding a transmission power corresponding to the common scheduling information within a common transmission format set for the common signaling scheme, and determining the transmission rate according to the selected transmission format Characterized in that the method. 18. The method of claim 17, wherein the common set of transport formats is The method as claimed in claim 1, wherein the UE is commonly applied to all UEs performing an uplink packet data service in a cell where the UE is located. 18. The method of claim 17, wherein the common set of transport formats is The method as claimed in claim 1, wherein the method is commonly applied to a predetermined group of user terminals including the user terminal. The method of claim 11, wherein the determining is performed. Detecting an error correction code from the scheduling information, if the error correction code is masked with a dedicated identifier assigned to the user terminal, it is determined that the scheduling information is the dedicated scheduling information, the error correction code is predetermined And if it is masked with a public identifier, determine that the scheduling information is the public scheduling information. The method of claim 11, wherein the determining is performed. If the scheduling information is spread with the dedicated orthogonal code assigned to the user terminal and is transmitted, the scheduling information is determined to be the dedicated scheduling information. If the scheduling information is spread with the predetermined common orthogonal code and the scheduling, the scheduling And determining that the information is the public scheduling information. An apparatus for transmitting scheduling information for scheduling an uplink packet data service from a user terminal from a base station to the user terminal, the apparatus comprising: A base station scheduler for allocating a transmission rate for the uplink packet data service and selecting a signaling scheme for notifying the transmission rate according to the allocated transmission rate as one of a dedicated signaling scheme and a common signaling scheme; When selected as the dedicated signaling scheme according to the selected signaling scheme, generates a dedicated error correction code masked with a dedicated identifier assigned to the user terminal, and when selected as the common signaling scheme, common error masked with a predetermined dedicated identifier. An error correction code generator for generating a correction code, A rate information generator for generating dedicated rate information indicating the rate or generating common rate information according to the selected signaling scheme; An error correction code adder for generating dedicated scheduling information by adding the dedicated error correcting code to the dedicated rate information, or generating common scheduling information by adding the common error correcting code to the common rate information; And a transmitter for transmitting the dedicated scheduling information or the common scheduling information to the user terminal. An apparatus for receiving scheduling information for scheduling an uplink packet data service from a user terminal from a base station to the user terminal, the apparatus comprising: A receiving unit receiving scheduling information indicating a transmission rate allocated for the uplink packet data service; An error correction code detector for detecting an error correction code from the scheduling information and reverse masking the error correction code with a dedicated identifier assigned to the user terminal or a predetermined public identifier; Inspecting the reverse masked error correction code, if an error occurs in the error correction code reverse masked with the dedicated identifier, the scheduling information is determined to be common scheduling information according to a common signaling method, and the reverse masked with the public identifier. An error correction code checker that determines that the scheduling information is dedicated scheduling information according to a dedicated signaling method when an error occurs in the error correction code; If the scheduling information is the dedicated scheduling information, the transmission format corresponding to the dedicated scheduling information is determined to be the maximum allowable transmission format of the user terminal. If the scheduling information is the public signaling information, the transmission power corresponding to the common scheduling information is determined. A rate information determiner determining the maximum allowable transmit power of the user terminal; And a rate controller for determining a transmission rate for the uplink packet data service within the maximum allowable transmission format or the maximum allowable transmission power. An apparatus for transmitting scheduling information for scheduling an uplink packet data service from a user terminal from a base station to the user terminal, the apparatus comprising: A base station scheduler for allocating a transmission rate for the uplink packet data service and selecting a signaling scheme for notifying the transmission rate according to the allocated transmission rate as one of a dedicated signaling scheme and a common signaling scheme; A rate information generator for generating dedicated rate information indicating the rate or generating common rate information according to the selected signaling scheme; A code controller for outputting a dedicated orthogonal code assigned to the user terminal when the dedicated signaling scheme is selected according to the selected signaling scheme, and outputting a predetermined common orthogonal code if the common signaling scheme is selected; And a transmitting unit configured to spread and transmit the dedicated data rate information to the dedicated orthogonal code, or to spread and transmit the common data rate information to the common orthogonal code. An apparatus for receiving scheduling information for scheduling an uplink packet data service from a user terminal from a base station to the user terminal, the apparatus comprising: Receive spread rate information indicating a rate allocated for the uplink packet data service, despread the spread rate information with a dedicated orthogonal code assigned to the user terminal to obtain dedicated rate information, and request A receiving unit for despreading the spread rate information with a predetermined common orthogonal code to obtain common rate information; If the dedicated data rate information indicates an increase or a decrease, an increase or decrease command is output according to the dedicated data rate information. If the dedicated data rate information is dedicated data rate indicating maintenance, the common data rate information is requested to the receiver. A rate information identifier for outputting an increase, decrease, or maintain command according to: And a rate controller for determining a rate for the uplink packet data service according to the increase, decrease, or maintain command.

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