KR100929074B1 - Scheduling method and apparatus for reverse data transmission for terminal located in soft handover area in mobile communication system - Google Patents

Abstract

A scheduling method and apparatus for efficiently controlling a reverse traffic rate of a mobile terminal located in a soft handover area in a mobile communication system supporting a reverse packet data service. The active set of the UE located in the soft handover area includes serving base stations and non-serving base stations. The mobile station acquires valid interval information for controlling reverse overloading of a non-serving base station adjacent to the serving base station of its own cell and does not request a rate increase (UP) as a rate request bit during the valid period corresponding to the valid interval information. By doing so, the serving base station does not increase the maximum allowed data rate. In another embodiment, the serving base station allocates the reverse data rate smaller than before to the mobile terminal during the valid period corresponding to the valid period information according to the valid period information indicating that the overload of the non-serving base station is valid.

WCDMA, UPLINK ENHANCEMENTS, SOFT HANDOVER, E-DCH, NODE B CONTROL SCHEDULING

Description

TECHNICAL FIELD OF THE INVENTION AND METHOD AND APPARATUS FOR SCHEDULE OF REVERSE DATA TRANSMISSION FOR A TERMINAL IN SOFT HANDOVER FIELD IN MOBILE COMMUNICATION SYSTEM

1 is a configuration diagram schematically showing a radio access network (UTRAN) of a third generation mobile communication system to which the present invention is applied.

2 is a hierarchical diagram illustrating an interface between a mobile terminal and a radio network controller (RNC).

3 is a conceptual diagram illustrating transmission of data through an E-DCH to which the present invention is applied.

4 is a message flow diagram illustrating an E-DCH transmission / reception procedure to which the present invention is applied.

5 is a diagram illustrating a scheduling operation of a mobile terminal located in a soft handover area according to the present invention.

FIG. 6 illustrates signaling for transmitting and receiving valid interval information between an RNC and a UE according to a first embodiment of the present invention; FIG.

7 is a flowchart illustrating an operation in which a mobile station transmits reverse data by using valid section information according to the first embodiment of the present invention.

8 is a flowchart illustrating an operation in which a mobile station transmits reverse data by using valid section information according to a second embodiment of the present invention.

9 is a diagram illustrating signaling for transmitting and receiving valid section information between an RNC and a base station according to a third embodiment of the present invention;

10 is a flowchart illustrating a scheduling operation of a base station that has received valid interval information according to a third embodiment of the present invention.

FIG. 11 is a diagram illustrating an operation of a signaling and a system for setting a length of an overloaded bit and a valid period in consideration of a transmission time interval of a mobile terminal according to an embodiment of the present invention. FIG.

The present invention relates to asynchronous wideband code division multiple access (WCDMA) communication. In particular, a mobile terminal located in a soft handover region provides an efficient scheduling method for reverse packet transmission.

The third generation, based on the European mobile system Global System for Mobile Communications (GSM) and General Packet Radio Services (GPRS), using Wideband Code Division Multiple Access (WCDMA). 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.

The UMTS uses the concept of virtual connection, which is a packet-switched connection using a packet protocol such as Internet Protocol (IP), and can always be connected to any other end in the network.

FIG. 1 is a diagram illustrating a UMTS Terrestrial Radio Access Network (hereinafter referred to as UTRAN) of a UMTS system.

Referring to FIG. 1, the UTRAN 12 is composed of radio network controllers (hereinafter referred to as RNCs) 16a and 16b and Node B's 18a, 18b, 18c, and 18d. Then, the mobile terminal (hereinafter referred to as UE) 20 is connected to the core network 10. There may be a plurality of cells below the node Bs 18a, 18b, 18c, and 18d, and each RNC 16a, 16b controls the corresponding node Bs 18a, 18b, 18c, and 18d. Each node B 18a, 18b, 18c, and 18d controls corresponding lower cells. One RNC and Node Bs and cells controlled by the RNC are collectively referred to as a Radio Network Subsystem (hereinafter referred to as RNS) 14a and 14b.

The RNCs 16a and 16b allocate or manage radio resources of the Node Bs 18a to 18d that they control. Node Bs 18a through 18d provide actual radio resources. Radio resources are configured for each cell, and radio resources provided by the Node Bs 18a to 18d mean radio resources of cells managed by the Bs. The terminal 20 may configure a radio channel and perform communication using radio resources provided by a specific cell of a specific Node B. From the standpoint of the terminal 20, the distinction between the Node Bs 18a to 18d and the corresponding cells is meaningless, and since only the physical layer configured for each cell is recognized, the Node Bs 8a to 18d and the cells have the same meaning. Will be mentioned.

The interface between the terminal 20 and the RNCs 16a and 16b is called a Uu interface, and a detailed hierarchical structure is shown in FIG. 2. The Uu interface is divided into a control plane used to exchange control signals between the terminal 20 and the RNCs 16a and 16b and a user plane used to transmit actual data.

Referring to FIG. 2, the control plane signal 30 includes a radio resource control (RRC) layer 34, a radio link control (RLC) layer 40, a media access control (MAC) layer 42, and physical (physical) signals. The user plane information 32 is processed through a Packet Data Control Protocol (PDCP) layer 36, a Broadcast / Multicast Control (BMC) layer 38, and an RLC layer 40. ), The MAC layer 42, and the physical layer 44. Among the layers shown here, the physical layer 44 is located in each cell, and the MAC layer 42 to the RRC layer 34 are located in the RNC.

The physical layer 44 is a layer that provides an information transmission service using a radio transfer technology, and corresponds to a first layer of an Open Systems Interconnection (OSI) model. The physical layer 44 and the MAC layer 42 are connected by transport channels, and transport channels are defined by the manner in which specific data is processed in the physical layer.                         

The MAC layer 42 and the RLC layer 40 are connected via logical channels. The MAC layer 42 delivers the data delivered by the RLC layer 40 through the logical channel to the physical layer through the appropriate transport channel, and the data delivered by the physical layer 44 through the transport channel through the appropriate logical channel. It serves to convey to 40. In addition, by inserting additional information into the data received through the logical channel or the transmission channel or by analyzing the inserted additional information, it takes appropriate action and controls the random access operation. The part related to the user plane in this MAC layer 42 is called MAC-d (MAC-data), and the part related to the control plane is called MAC-control (MAC-control).

The RLC layer 40 is responsible for establishing and releasing logical channels. The RLC layer 40 may operate in one of three operation modes such as an acknowledgment mode (AM), an unacknowledged mode (UM), and a transparent mode (TM), and provide different functions for each operation mode. In general, the RLC layer 40 is responsible for dividing or assembling a service data unit (hereinafter referred to as SDU) from an upper layer into an appropriate size, and an error correction function.

The PDCP layer 36 is located above the RLC layer 40 in the user plane. The PDCP layer 36 compresses and restores headers of data transmitted in the form of an IP packet, and an RNC providing a service to a specific terminal is provided by the mobility of the terminal. It is responsible for lossless data transfer function under the changed situation.

The characteristics of a transport channel connecting the physical layer 44 and upper layers include physical layer processing such as convolutional channel encoding, interleaving, and service-specific rate matching. It is determined by the transport format (TF) specified.

In particular, in the UMTS system, an enhanced uplink dedicated channel is further improved to further improve the performance of packet transmission in uplink (UL) communication from a user equipment (UE) to a base station (BS). : Hereinafter referred to as E-DCH). E-DCH supports technologies such as Hybrid Automatic Retransmission Request (HARQ) and Node B controlled scheduling in order to support more stable high-speed data transmission.

3 is a conceptual diagram illustrating transmission of reverse packet data through an E-DCH in a wireless reverse link.

Here, reference numeral 100 denotes a Node B supporting the E-DCHs 111 to 114, and reference numerals 101, 102, 103, and 104 are terminals for transmitting the E-DCH. The node B 100 determines the channel status of the terminals 101 to 104 using the E-DCHs 111 to 114 to schedule data transmission of the terminals 101 to 104. The scheduling allocates a low data rate to the terminal 104 far from the node B 100 while the measured noise rise value of the node B 100 does not exceed the target value in order to improve the performance of the entire system. In addition, the terminal 101 is located in a manner of assigning a high data rate.

4 is a message flow diagram illustrating a transmission and reception procedure through an E-DCH.                         

Referring to FIG. 4, in step 202, the Node B and the UE configure an E-DCH. The configuration process 202 includes the delivery of messages over a dedicated transport channel. If the E-DCH is configured, the UE informs the Node B of the scheduling information in step 204. The scheduling information may be terminal transmission power information indicating a reverse channel state, extra power information that can be transmitted by the terminal, and an amount of data to be transmitted in a buffer of the terminal.

Node B monitors scheduling information from the plurality of terminals in step 206 to schedule data transmission of each terminal. Specifically, in step 208, the Node B determines to allow backward packet transmission to the terminal and transmits scheduling assignment information to the terminal. The scheduling allocation information includes an absolute grant (AG) directly indicating the maximum data rate allowed and a relative grant (RG) indicating the increase / decrease / maintenance of the maximum allowed data rate relative to a previous value. ). In this case, the absolute grant and the relative grant, which are the scheduling allocation information, are transmitted by dedicated signaling used for each terminal, or common signaling to all terminals belonging to one or more terminal groups or one cell. ) May be sent.

The terminal determines the transport format (TF) of the E-DCH to be transmitted in the reverse direction within the allowed maximum data rate using the scheduling allocation information in step 210, and in step 214, the E-DCH is determined. The TF information is transmitted to the Node B in step 212 while simultaneously transmitting reverse (UL) packet data. In step 216, the Node B determines whether there is an error in the TF information and the packet data. In step 218, the node B receives a non-acknowledge (NACK) when an error occurs in any one of the determination results, and receives an acknowledgment (ACK) when all errors are found through the ACK / NACK channel. Send to the terminal.

When the ACK is transmitted, the terminal transmits new user data through the E-DCH when packet data is completed, but when the NACK is transmitted, the terminal retransmits the packet data having the same contents through the E-DCH.

Since the E-DCH described above has been developed to improve the packet transmission performance of the transport channel, the E-DCH has the basic characteristics of the dedicated channel, one of which is soft handover support. That is, the terminal in the soft handover area may receive forward information from all of the Node Bs in the active set. Accordingly, the terminal located in the soft handover area receives scheduling allocation information from all Node Bs in the active set in order to transmit the E-DCH. In this case, since the UE may receive different scheduling allocation information from the Node Bs belonging to the active set, it is necessary to determine whether to transmit the E-DCH from the different scheduling permission information.

In a communication system supporting the E-DCH according to the prior art, in scheduling uplink data transmission of a terminal in a soft handover region, all base stations belonging to the active set transmit scheduling allocation information to the terminal, thereby providing a code of a forward channel. There was a problem in that an overhead occurs in terms of resources or transmission power resources, and it was difficult for a terminal that received the plurality of scheduling assignment information to determine transmission of an E-DCH.

The present invention provides a method and apparatus for efficiently scheduling an enhanced uplink transport channel (E-DCH) used by a terminal located in a soft handover area in a mobile communication system.

The present invention provides a method and apparatus for scheduling reverse data transmission in consideration of base stations other than the serving base station while being included in an active set in a terminal located in a soft handover area.

The present invention provides a method and apparatus for scheduling reverse data transmission for determining a transmission rate of reverse packet transmission using scheduling allocation information received from base stations included in an active set in a terminal located in a soft handover region.

The present invention provides a method and apparatus for scheduling reverse data transmission for a terminal located in a soft handover area to receive interval information indicating whether scheduling assignment information of a non-serving base station is valid from a wireless network controller.

The present invention provides a method and apparatus for scheduling reverse data transmission for a serving base station located in a soft handover area to receive interval information indicating whether scheduling assignment information of a non-serving base station is valid from a wireless network controller.

The present invention relates to a scheduling method of reverse data transmission for newly setting interval information indicating validity of scheduling allocation information of a predetermined base station in an active set in consideration of different transmission time intervals of a plurality of mobile terminals located in a soft handover area. Provide the device.

In a mobile communication system supporting a reverse packet data service according to the present invention, a method for scheduling reverse data transmission of a mobile terminal is performed in communication with one serving base station and at least one non-serving base station by soft handover. Receiving dedicated scheduling allowance information according to a dedicated scheduling assignment from a base station, and receiving at least one common scheduling allowance information according to a common scheduling assignment from the at least one non-serving base station, and wherein the common scheduling allowance information is a reverse data rate. If a DOWN is indicated, controlling the reverse data rate so that the reverse data rate does not exceed the previous reverse data rate during a predetermined valid period, regardless of the dedicated scheduling permission information, and using the controlled reverse data rate. Transmitting the reverse data.

In addition, in a mobile communication system supporting a reverse packet data service according to the present invention, a method for scheduling reverse data transmission of a mobile station by a base station allows a mobile station located in a soft handover region to allow dedicated scheduling according to a dedicated scheduling assignment. Transmitting information, receiving the reverse data from the mobile terminal after transmitting the dedicated scheduling permission information, and if the data rate of the received reverse data is less than the data transmission rate according to the dedicated scheduling permission information, Controlling the reverse data rate of the mobile terminal not to exceed the previous reverse data rate during a predetermined validity period; and transmitting dedicated scheduling allowance information indicating the controlled reverse data rate to the mobile terminal. The.

In addition, an apparatus for scheduling reverse data transmission of a mobile terminal in a mobile communication system supporting a reverse packet data service according to the present invention, includes one serving base station and at least one non-serving base station related to a soft handover area, and the soft hand. Located in an over area, and receiving dedicated scheduling allowance information according to a dedicated scheduling assignment from the serving base station and at least one common scheduling allowance information according to a common scheduling assignment from the at least one non-serving base station, and receiving the common scheduling allowance information. Indicates a decrease of the reverse data rate, regardless of the dedicated scheduling allowance information, the reverse data rate is controlled so that the reverse data rate does not exceed the previous reverse data rate during a predetermined valid period, thereby controlling the reverse data rate. Used to include the mobile terminal for transmitting uplink data to the serving base station and the non-serving base station.

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Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. 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.

The main subject of the present invention described below is to schedule reverse data transmission of a mobile terminal located in a soft handover area in providing an enhanced reverse packet data service in a mobile communication system.

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A mobile station located in a soft handover area and a primary scheduling Node B for scheduling reverse data transmissions of the mobile station and other mobile stations for reverse packet data transmission (hereinafter referred to as a "serving Node B"). And a non-primary scheduling Node B (hereinafter referred to as a "non-serving Node B") included in an active set of the mobile station but not the serving base station. ), And the mobile terminal located in the soft handover area receives the scheduling assignment information of the serving base station and the scheduling assignment information of the non-optimal scheduling to perform reverse packet data transmission.

As described above, the mobile terminal in the soft handover area receives scheduling assignment information as signaling related signaling from the serving base station and at least one non-serving base station. At this time, the scheduling method of the serving base station and the non-serving base station for the mobile terminal is different. That is, the serving base station performs scheduling for the mobile terminal located in the soft handover area using dedicated signaling, while the non-serving base station performs scheduling using common signaling. In other words, the serving base station transmits scheduling assignment information through a dedicated channel to satisfy the reliability required by the mobile station, and the non-serving base station transmits scheduling assignment information through a common channel. The scheduling operation of the above-mentioned serving base station and non-serving base station will be described in more detail below.

5 is a diagram illustrating a scheduling operation of a user terminal located in a soft handover area according to an embodiment of the present invention.

Referring to FIG. 5, the first and second mobile terminals UE1 and UE2 504 and 505 are located in the soft handover area. Here, the first mobile terminal 504 manages an active set including first and second base stations Node B1 and Node B2 501 and 502, and the first base station 501 manages the first mobile. The serving base station of the terminal 504. The second mobile terminal 505 manages an active set comprising second and third base stations (Node B2, Node B3) 502, 503, and the third base station 503 is connected to the second mobile terminal 505. Serving base station.

In this case, the base stations 501 to 503 perform scheduling using the state information of the mobile terminals 504 and 505. To this end, mobile terminals 504 and 505 transmit terminal state information on the reverse link. In general, UE state information includes information transmitted through an enhanced dedicated physical data channel (hereinafter, referred to as an 'E-DPDCH') to which an E-DCH is mapped regardless of reverse packet data. When the backward packet data exists, there is information transmitted through an enhanced dedicated physical control channel (hereinafter, referred to as an 'E-DPCCH'), which is a physical channel for transmitting control information of the E-DCH.

Here, the state information transmitted through the E-DPDCH includes buffer state information and transmit power information. The buffer status information and the transmission power information may be transmitted to the base station using a MAC-e signaling method, which is a method of being included in the E-DCH MAC-e protocol data unit (hereinafter referred to as PDU) and transmitted. Can be.

On the other hand, information transmitted through the E-DPCCH when there is reverse packet data includes rate request information. Other information transmitted through the E-DPCCH may include a transport format indicator (TFI), a retransmission sequence number, and a quality of service (hereinafter, referred to as 'TFT') indicating a transmission format of data transmitted through the E-DPDCH. QoS '), power boost, and the like.

In this case, the rate request information is composed of 1 bit or more bits, and the mobile terminal requests the serving base station for a rate to be transmitted next, using the rate request information. For example, when one bit rate request bit is used, when the bit rate request bit is set to 1, it means that an increase rate is requested. On the other hand, if the rate request bit is set to 0, it indicates that there is no need to increase the rate. That is, when the rate request bit is set to UP, it means a request to allocate a higher data rate for the next E-DCH transmission to the Node B Scheduler of the serving base station, and the rate request bit is set to UP. If not, it means that the mobile terminal is satisfied with the current data rate.

The base stations 501 to 503 may use the mobile terminals (hereinafter referred to as TTIs) in consideration of the state information provided from the mobile terminals 504 and 505 and their radio resource capacity. For 504 and 505, whether to allow reverse data transmission and maximum data rate allowed are determined, respectively. This is called scheduling. Then, the first and third base stations 501 and 503 inform the mobile stations 504 and 505 of the maximum data rate allowed according to the scheduling by using dedicated signaling, and the second base station 502 uses the mobile terminals. 504, 505 are notified of the scheduling result using common signaling. In this case, when the reverse resource situation of cells managed by the second base station 502 is not good, the second base station 502 informs the mobile stations 504 and 505 that it is an overload of the reverse resource. . That is, the mobile station 504 or 505 having the second base station 502 as a non-serving base station transmits a DOWN command to lower the transmission rate of reverse data.

In more detail, the first base station 501 transmits dedicated scheduling grant information 506 indicating the maximum data rate allowed to the mobile station 504, and the third base station 503. In addition, the mobile station 505 transmits dedicated scheduling allowance information 507 indicating the maximum data rate allowed. On the contrary, the second base station 502 transmits common scheduling grant information 508 to the mobile terminal 504 and the mobile terminal 505. That is, for the mobile terminals 504 and 505 including the second base station 502 in the active set as the non-serving base station, the second base station 502 forwards the common scheduling grant information 508 in the forward direction. The common scheduling grant information 508 indicates a common change in reverse data rate for both the mobile terminals 504 and 505. Accordingly, each of the mobile stations 504 and 505 may have dedicated scheduling permission information 506 and 507 received from the first or third base station 501 and 503 and common scheduling permission information transmitted from the second base station 502. 508 to determine the transmission format (TF) of the E-DCH, and transmit the reverse data (509, 510) and the TF information for the reverse data through the E-DPDCH and E-DPCCH according to the determined transmission format do.

As described above, the mobile terminal located in the soft handover area informs the base station of the active set of the terminal state information using E-DPCCH or MAC-e signaling, and the base stations use the mobile state using the terminal state information and the like. Schedule reverse data transmission by the terminal. At this time, the mobile terminal determines the transmission format of the E-DCH by combining the dedicated scheduling permission information received from the serving base station and the common scheduling permission information received from the non-serving base station.

Embodiments described below relate to schemes for processing common scheduling grant information when the mobile terminal receives common scheduling grant information from at least one non-serving base station in addition to dedicated scheduling grant information from the serving base station.

First embodiment

The mobile terminal located in the soft handover region receives an overload bit as dedicated scheduling grant information from the serving base station and common scheduling grant information from the non-serving base station. When the overload bit means 0, the mobile station determines the reverse data rate according to the dedicated scheduling allowance information from the serving base station. However, when the overload bit is set to 1, the mobile terminal controls the reverse data rate not to increase during a predetermined valid period when the overload bit is set.

That is, the mobile terminal receiving the overload bit from the non-serving base station operates in consideration of the overload bit of the non-serving base station, instead of operating according to the dedicated scheduling permission information received from the serving base station. However, the rate request bit according to the transmission of the E-DCH is not set to the optimal base station to UP. This is to ensure that the reverse data rate in the next TTI does not exceed the rate of the current TTI. The valid period indicating the period for which the UP is not requested by the rate request bit may be provided by the mobile terminal or provided from the RNC.

6 is a diagram illustrating signaling for transmitting and receiving valid interval information between an RNC and a UE according to the first embodiment of the present invention.

Referring to FIG. 6, the RNC 603 transmits validity duration information 604 indicating a valid duration of an overload bit set by the non-serving base station to the mobile terminal 601 through the base station 602. . That is, the RNC 603 detects that the overload bit set by the non-serving base station existing in the active set of the mobile terminal 601 is set to perform the limited operation according to the overload bit. The valid section information 604 indicating the time is transmitted to the mobile terminal 601.

In this case, the RNC 603 uses RRC signaling to transmit the valid section information 604 to the mobile terminal 601. In addition, the mobile terminal 601 is located in a soft handover area, and obtains a valid section of the set overload bit of the non-serving base station existing in the active set from the valid section information 604. In addition, the valid period information 604 may be set differently according to mobile terminals or differently according to non-serving base stations. In another embodiment, the valid period information 604 is set according to a quality of service (QoS) of reverse data, a currently set transmission rate, or state information of a mobile terminal.

As described above, the mobile station 601 receiving the valid section information 604 of the overload bit from the RNC 603 transmits reverse data according to the optimal transmission rate during the valid section according to the valid section information 604. Rather than doing so, you will perform a limited operation. The limited operation will be described with reference to FIG. 7.

7 is a flowchart illustrating an operation of transmitting reverse data by a mobile terminal using valid section information according to the first embodiment of the present invention.

Referring to FIG. 7, in step 701, the mobile terminal is located in the soft handover area. In step 702, the mobile station located in the soft handover area receives the valid interval information on the overload bits of the non-serving base station from the RNC using RRC. In other cases, the mobile terminal reads information on the valid section of the overloaded bits from the internal memory.

In step 703, the mobile terminal receives dedicated scheduling grant information from the serving base station, and receives an overload bit as common scheduling grant information at the non-serving base station.

In step 704, the mobile terminal determines whether the overload bit received from the non-serving base station is set to one. If it is confirmed in step 704 that the overload bit is set to 1, the process proceeds to step 705 and the mobile terminal starts the timer T by setting the valid period VD according to the valid period information and then proceeds to step 706. . Here, the valid period represents a multiple of a transmission time interval (hereinafter referred to as TTI) indicating a transmission unit of an E-DCH, and is set to make uplink resources of the non-serving base station relaxed during the valid period. . On the other hand, if the overload bit is not set to 1, that is, if it is detected that there is no overload at the non-serving base station, the process proceeds directly to the step 706.

In step 706, the mobile terminal determines whether the set value T of the timer is greater than zero. When the set value T of the timer is greater than 0, the set value T of the timer is reduced by 1 in step 707, and reverse data is transmitted through the E-DCH according to a predefined method in step 709. Specifically, the transmission rate of the E-DCH is set to be one step smaller than the previous TTI, or controlled to no longer increase the reverse resource of the non-serving base station. In step 709, the mobile station recognizes that an uplink resource of the non-serving base station is overloaded, so that the rate of transmission of the E-DCH is prevented so that the uplink data transmitted by the mobile terminal does not increase the portion of the uplink resource of the non-serving base station. Set. Here, the previous transmission rate may mean a transmission rate at the time when the overloaded bit is received.

In addition, in step 709, the mobile station transmits transmission format information for the reverse data through the E-DPCCH for transmitting control information related to the E-DCH, wherein the rate request bit transmitted through the E-DPCCH is UP. Is set to a non-value. That is, the mobile terminal ignores other state information and sets the rate request bit to a value other than UP. Setting the rate request bit to a value other than UP may allow all mobile terminals to perform the same or differently set according to the priority of the mobile terminals or the configuration of the RNC. The valid period can also be used to limit MAC-e signaling. When MAC-e signaling is used, the serving base station can allocate more resources to the mobile terminal, but the mobile terminal cannot use that much resource, resulting in poor system performance. Accordingly, the mobile terminal may limit MAC-e signaling during the valid period of the overload bit.

On the other hand, if the set value T of the timer in step 706 is not greater than zero, the mobile terminal proceeds to step 710 to transmit reverse data through the E-DCH according to the dedicated scheduling grant information from the serving base station. That is, in step 710, the mobile terminal ignores the overload bit from the non-serving base station in setting the transmission rate of the E-DCH, and uses only dedicated scheduling permission information received from the serving base station. In addition, the mobile terminal also sets a value of UP or non-UP according to the state of the mobile terminal even when setting a rate request bit to be transmitted through the E-DPCCH.

As described above, in the first embodiment, the non-serving base station in the active set transmits the overload bit as common scheduling grant information to the mobile terminal located in the soft handover area. The serving base station allocates reverse resources to the mobile terminal using a dedicated scheduling allocation scheme.

The mobile station receiving the overload bit from the non-serving base station selects an E-DCH transmission rate in consideration of the uplink resource of the non-serving base station according to the valid interval information of the overload bit and transmits the reverse data.

Second embodiment
A mobile station located in the soft handover area receives an overload bit as common scheduling grant information from a non-serving base station, and allocates reverse resources by receiving dedicated scheduling grant information from a serving base station. At this time, if it is detected that the overload bit from the non-serving base station is not set to 1, the mobile station operates according to whether the currently transmitted reverse data is initial transmission or retransmission in allocating the reverse resource. In other words, if the non-serving base station is overloaded and the reverse data to be transmitted is initial transmission, the mobile station ignores the dedicated scheduling permission information received from the serving base station and sets the rate request bit to a value other than UP.
8 is a flowchart illustrating an operation in which a mobile station transmits reverse data by using valid section information according to a second embodiment of the present invention.

In FIG. 8, when the mobile terminal transmits reverse data, a method for informing whether the data to be transmitted is initial transmission is proposed.

In determining the rate of reverse data transmission, the mobile terminal considers whether the reverse data to be transmitted is initial transmission or retransmission.

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Referring to FIG. 8, in step 801, the mobile terminal is located in the soft handover area. In step 802, the mobile station located in the soft handover area receives the corresponding scheduling assignment information from the serving base station and the non-serving base station in the active set. Specifically, dedicated scheduling permission information is received from the serving base station, and an overload bit is received as common scheduling permission information from the non-serving base station.
In step 803, the mobile terminal determines whether the overload bit is set to one. If the reverse bit of the non-serving base station is overloaded as the overload bit is set to 1, the mobile station does not designate a rate request bit of the E-DPCCH in the next E-DCH transmission in step 804. And proceed to step 805. This is for the serving base station to allocate the reverse resource for the mobile terminal in a limited schedule in scheduling the next E-DCH transmission, to eliminate the overload of the reverse resource of the non-serving base station. On the other hand, if the overload bit is not set to 1 in step 803, the flow proceeds directly to step 806.

In step 805, the mobile terminal sets the initial transmission tag to 1 in order to commence initial transmission.
In step 806, the mobile station determines whether the initial transmission tag is 1 while the reverse data to be transmitted is initial transmission. If the condition of step 806 is satisfied, in step 807, the mobile station ignores dedicated scheduling allocation information from the serving base station in setting the transmission rate of the E-DCH, and transmits reverse data through the E-DCH according to a predefined scheme. send. In this predefined scheme, the reverse data rate of the non-serving base station is no longer increased, such as setting the reverse data rate one step smaller than the previous transmission or maintaining the data rate of the previous transmission. Perform the action.

On the other hand, if the condition of step 806 is not satisfied, the mobile terminal proceeds to step 808 and sets the initial transmission tag to zero. Then, in step 809, the mobile terminal ignores the overload bit from the non-serving base station and transmits data through the E-DCH using the dedicated scheduling grant information received from the serving base station. That is, the E-DCH transmission rate is determined according to the dedicated scheduling allowance information received from the serving base station. In this case, the rate request bit of the E-DPCCH may be set according to the state of the mobile terminal.

Third embodiment

The mobile station is located in the soft handover area, where a non-serving base station in an active set transmits an overload bit as common scheduling grant information to the mobile station. The serving base station transmits dedicated scheduling permission information to the mobile terminal.

The mobile terminal receives dedicated scheduling grant information from the serving base station and overloaded bits from the non-serving base station. At this time, if the overload bit from the non-serving base station means 0, the mobile station allocates a reverse resource according to the dedicated scheduling permission information from the serving base station. On the other hand, if the overload bit from the non-serving base station is set to 1, the operation of the mobile terminal is limited as follows.

In other words, the mobile terminal that detects the situation in which the overload bit is set, sets the rate request bit to a value other than UP, and operates according to a predefined scheme for initial transmission occurring in the nearest future. As an example, the mobile terminal uses a data rate one step lower than the dedicated scheduling allowance information from the optimal base station, or uses a data rate one step lower than the data rate of the previous transmission.

In this regard, in the third embodiment, the RNC delivers the validity interval for the overload bit to the serving base station, and the serving base station allows the mobile terminal in soft handover to make dedicated scheduling of the serving base station according to the validity interval. The reverse data transmission of the mobile terminal is controlled to use a data rate smaller than the information. That is, the non-serving base station of the mobile terminal determines that the mobile station is excessive during the valid period, and allocates relatively less reverse resources to the mobile terminal than the corresponding state information during the valid period.

9 is a diagram illustrating signaling for transmitting and receiving valid interval information between an RNC and a base station according to the third embodiment of the present invention.

Referring to FIG. 9, the RNC 902 signals the serving base station 901 to the valid base section information 903 indicating the valid section of the overload bit set by the non-serving base station. The valid period information 903 is transmitted through Node B Application Protocol (NBAP) signaling. In this case, when the RNC 902 is not a drift RNC that actually controls the serving base station 901, the valid interval information 903 is transmitted through RNSAP signaling and NBAP signaling.

Here, the valid period information 903 may be set differently according to mobile terminals or differently according to non-serving base stations. In another embodiment, the valid period information 903 is set in consideration of QoS, current transmission rate, status information of the mobile terminal, and the like. In addition, the valid period information 903 may be transmitted when the mobile terminal includes the non-serving base station as an active combination, and may also be transmitted when the valid period is changed.

10 is a flowchart illustrating a scheduling operation of a base station that has received valid interval information according to a third embodiment of the present invention.

Referring to FIG. 10, in step 1001, a serving base station receives valid interval information of an overload bit for a mobile terminal located in a soft handover area while being scheduled by the serving base station from the RNC. In other cases, the serving base station reads valid interval information of predetermined overload bits from the internal memory. In step 1002, the serving base station transmits dedicated scheduling permission information to the mobile terminal and receives reverse data from the mobile terminal through E-DCH in step 1003.

In step 1004, the serving base station compares the data rate allocated to the mobile station using the dedicated scheduling permission information with the data rate used for reverse data received from the mobile station. At this time, if the used data rate is smaller than the allocated data rate, the process proceeds to step 1005 and the mobile station is considered to have received an overload bit from the non-serving base station. That is, backward resources of the non-serving base station adjacent to the serving base station are overloaded so that the mobile station determines that the overload bit is instructed.

In step 1006, the serving base station sets the timer T to the valid period VD according to the valid period information, starts it, and then proceeds to step 1007. In step 1007, the serving base station determines whether the set value T of the timer is greater than zero. If the set value T of the timer is greater than zero, the serving base station decreases the set value T of the timer by 1 in step 1007 and allocates a relatively small backward resource to the mobile terminal in step 1009. That is, the serving base station determines that the non-serving base station of the mobile terminal is an overload situation, and allocates slightly less uplink resources to the mobile terminal than other mobile terminals. As an example, the serving base station controls the reverse data rate of the mobile terminal not to exceed the previous data rate. On the other hand, if the timer set value T is not greater than zero, in step 1011, the serving base station allocates the optimized reverse resource to the mobile terminal. That is, the reverse transmission rate of the mobile terminal is guaranteed to the maximum.

Third embodiment

Hereinafter, a scheduling operation when a transmission time interval (hereinafter, referred to as 'TTI') of a plurality of mobile terminals located in the soft handover area is different from each other will be described.

It is effective to set the valid period of the overloaded bit to be the same for each of the plurality of mobile terminals receiving the overloaded bit.

Therefore, when mobile terminals using a 2 ms TTI and terminals using a 10 ms TTI are simultaneously located in a soft handover area, there is a need for a method in which the valid period of the overload bit should be set to the same for the mobile terminals. Done.

For example, when only mobile terminals using a 2 ms TTI are located in the soft handover area, that is, when there are no mobile terminals using the 10 ms TTI, the transmission length of the overload bit is set in units of 2 ms. Then, the effective period of the overload bit is also set in units of 2ms.

On the other hand, when the mobile terminals using the 2ms TTI and the mobile terminals using the 10ms TTI coexist in the soft handover area, the mobile terminals of the 10ms TTI and the mobile terminals of the 2ms TTI are in the soft handover area. The overload bit is commonly received from the associated non-serving base station. In this case, the timing at which the overload bit is transmitted to the mobile terminals using the 2 ms TTI and the mobile terminals using the 10 ms TTI may be different. Therefore, the timing for receiving the overload bit should be newly set. do. In addition, the valid period of the overload bit must also be newly set.

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As such, when the 2 ms TTI mobile terminals and the 10 ms TTI mobile terminals exist together in the soft handover region, the transmission length of the overload bit transmitted from the non-serving base station corresponds to the case where only 10 ms TTI mobile terminals exist. Similarly, it is desirable to set it to 10ms.

This is to apply the transmission length of the overload bit to both the mobile stations of the 2ms TTI and the mobile terminals of the 10ms TTI. The valid period of the overload bit is then determined to be an integer multiple of 10 ms.

The following various methods may be used to set the transmission length of the overload bit and the length of the valid period for the mobile terminals in the soft handover region.

The first method does not consider whether the mobile terminals present in the soft handover area use 2 ms TTI or 10 ms TTI, and always set the overload bit to 10 ms in length. Therefore, the valid period of the overload bit is set to an integer multiple of 10 ms. The first method uses a 10 ms long overload bit even if only 2 ms TTI mobile terminals exist in the soft handover region.

The second method is for the RNC to individually determine the TTIs of the mobile terminals located in the soft handover area, and notify the mobile stations and the base stations involved in the soft handover area of the transmission length of the overload bit.

11 is a diagram illustrating signaling for transmitting and receiving valid period information to mobile terminals of a soft handover area having different TTIs according to a preferred embodiment of the present invention. Although only one base station 1102 related to the soft handover area and one mobile terminal 1101 located in the soft handover area are shown here, the same description applies to the base station and the mobile terminal not shown. to be. As shown

The mobile terminal 1101 and the base station 1102 receive the transmission length information of the overload bit from the RNC 1103 through the RRC signaling and the NBAP signaling, and the overload bit based on the transmission length information received from the RNC 1103. Performs transmission and reception, and changes the valid interval setting of the overload bit.

Referring to FIG. 11, in step 1104, the mobile terminal 1101 reports its TTI information 1104 to the RNC 1103 through an RRC message.

In step 1105, the RNC 1103 receives the TTI information of the mobile terminal 1101 which belongs to the base station 1102 and is located in the soft handover area, and confirms the TTI information to locate the plurality of soft handover areas. Set the transmission length of the overload bit to be applied in common to the mobile terminals of. Here, the transmission length of the overload bit is determined using TTI information received from a plurality of mobile terminals located in the soft handover region including the mobile terminal 1101.

In step 1106, the RNC 1103 transfers transmission length information of the overloaded bits indicating the transmission length of the overloaded bits to the base station 1102 using NBAP signaling.

In step 1108, the base station 1102 stores the transmission length of the overload bit in response to the transmission length information of the overload bit, and sets the valid period of the overload bit by an integer multiple of the transmission length of the overload bit. Here, the base station 1102 is a base station included in an active set of the mobile terminal 1101.

In addition, in step 1107, the RNC 1103 transmits the transmission length information of the overload bit to the mobile terminal 1101 using RRC signaling.

In step 1109, the mobile terminal 1101 stores the transmission length of the overload bit in response to the transmission length information of the overload bit, and sets the valid period of the overload bit by an integer multiple of the transmission length of the overload bit in step 1110. . Subsequently, the mobile terminal 1101 receives the overloaded bit from the non-serving base station according to the transmission length of the overloaded bit.

The method of the present invention described above may be somewhat specific, but is not limited to the above description, and various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the method described above, 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 mobile stations located in the soft handover area allocate reverse resource, when the common scheduling allowance information of the non-serving base station indicates an overload, the entire mobile station is prevented from increasing the reverse data rate during a predetermined valid period. It has the advantage of increasing the efficiency of the communication system.

Claims (20)

A method for scheduling reverse data transmission of a mobile terminal in a mobile communication system supporting a reverse packet data service, During communication with one serving base station and at least one non-serving base station by soft handover, receiving dedicated scheduling permission information according to a dedicated scheduling assignment from the serving base station, and receiving a common scheduling assignment from the at least one non-serving base station. Receiving at least one common scheduling grant information according to: If the common scheduling grant information indicates a decrease of a reverse data rate, controlling the reverse data rate not to exceed the previous reverse data rate during a predetermined validity period, regardless of the dedicated scheduling allowance information; And transmitting reverse data using the controlled reverse data rate. The method of claim 1, wherein the controlling process comprises: During the validity period, the rate request bit included in the control information transmitted with the reverse data is set to a value other than an increase (UP). The method of claim 1, And determining the valid period according to a length of a transmission time interval (TTI) for transmitting the reverse data. The method of claim 1, wherein the common scheduling permission information, And an overload bit indicating whether the reverse resource of the corresponding non-serving base station is overloaded. The method of claim 1, wherein when the common scheduling allowance information does not indicate a decrease of a reverse data rate, the reverse data rate is determined according to the dedicated scheduling allowance information, and the reverse data rate is transmitted according to the determined reverse data rate. The method of claim 1, further comprising the step of. 6. The method of claim 5, wherein when the common scheduling permission information does not indicate a decrease in reverse data rate, the rate request bit included in control information transmitted together with the reverse data is set according to the state of the mobile terminal. Characterized in that, the scheduling method of the reverse data transmission. The method of claim 1, wherein the valid period is, And receiving from the radio network controller (RNC) controlling radio resources of the mobile terminal to the mobile terminal through radio resource control (RRC) signaling. A method for scheduling reverse data transmission of a mobile terminal by a base station in a mobile communication system supporting reverse packet data service, Transmitting, to the mobile terminal located in the soft handover area, dedicated scheduling permission information according to dedicated scheduling assignment; Receiving reverse data from the mobile terminal after transmitting the dedicated scheduling permission information; If the data rate of the received reverse data is less than the data rate according to the dedicated scheduling permission information, controlling the reverse data rate of the mobile terminal not to exceed the previous reverse data rate during a predetermined valid period; And transmitting to the mobile terminal dedicated scheduling permission information indicating the controlled reverse data rate. 9. The method of claim 8, further comprising determining the valid period according to a length of a transmission time interval (TTI) for transmitting the reverse data. The method of claim 8, wherein the validity interval, And receiving from the radio network controller (RNC) controlling the radio resources of the mobile terminal to the base station through Node B Application Part (NBAP) signaling. An apparatus for scheduling reverse data transmission of a mobile terminal in a mobile communication system supporting a reverse packet data service, At least one serving base station and at least one non-serving base station related to the soft handover area; Located in the soft handover area, the dedicated scheduling allowance information according to the dedicated scheduling assignment is received from the serving base station, and at least one common scheduling allowance information according to the common scheduling assignment is received from the at least one non-serving base station, and the common If the scheduling permission information indicates a decrease of the reverse data rate, the reverse data rate is controlled so that the reverse data rate does not exceed the previous reverse data rate during a predetermined valid period irrespective of the dedicated scheduling permission information. And a mobile terminal for transmitting reverse data to the serving base station and the non-serving base station using a data rate. The method of claim 11, wherein the mobile terminal, During the validity period, the rate request bit included in the control information transmitted with the reverse data is set to a value other than UP. The method of claim 11, wherein the validity interval, And a length of a transmission time interval (TTI) for transmitting the reverse data. The method of claim 11, wherein the common scheduling permission information, And indicating whether or not the reverse resource of the non-serving base station is excessive. The method of claim 11, wherein the mobile terminal, If the common scheduling allowance information does not indicate a decrease in the reverse data rate (DOWN), the reverse data rate is determined according to the dedicated scheduling allowance information, characterized in that for transmitting the reverse data according to the determined reverse data rate, Scheduling device for reverse data transmission. The method of claim 15, wherein the mobile terminal, When the common scheduling allowance information does not indicate a decrease of a reverse data rate, the rate request bit included in control information transmitted together with the reverse data is set according to the state of the mobile terminal. Scheduling device for reverse data transmission. The method of claim 11, wherein the validity interval, And receiving from the radio network controller (RNC) controlling radio resources of the mobile terminal to the mobile terminal through radio resource control (RRC) signaling. delete delete delete

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