KR20090016175A - Method for transmitting channel measurement result in wirelss communication system - Google Patents

Abstract

A method for transmitting a channel measurement result in a wireless communications system using a mode which mixes two kinds of concepts is provided to reduce signaling load by using second discrimination mode in order to efficiently use the radio resource. Network transmits the measurement control information to a terminal through a measurement control message(S610). The channel measurement result is transmitted through network(S630). Network delivers the measurement control information to the terminal through the measurement control message. The measurement result is reported in network. According to the measurement control information is the RRC(Radio Resource Control) mode of the terminal, it is transmitted to the terminal through the other route. The measurement control message is received through the DCCH(Dedicated Control Channel).

Description

Method for transmitting channel measurement result in wirelss communication system}

The present invention relates to a wireless communication, and relates to a method for transmitting a channel measurement result in a wireless communication system.

3rd generation partnership project (3GPP) mobile communication systems based on wideband code division multiple access (WCDMA) wireless access technology are widely deployed around the world. High Speed Downlink Packet Access (HSDPA), which can be defined as the first evolution of WCDMA, provides 3GPP with a highly competitive wireless access technology in the mid-term future. However, as the demands and expectations of users and operators continue to increase, and the development of competing wireless access technologies continues to progress, new technological evolution in 3GPP is required to be competitive in the future. Reduced cost per bit, increased service availability, the use of flexible frequency bands, simple structure and open interface, and adequate power consumption of the terminal are demanding requirements.

The measurement procedure provides a variety of information needed to support appropriate network management and resource allocation considering the wireless environment. In general, in the measurement procedure, a terminal transmits a measurement result of a channel state to a base station. There are two ways to perform measurement procedures: event-triggered reporting and periodic reporting. The event triggering report is a method in which a terminal transmits a channel measurement result to a base station according to a specific condition. The periodic report is a method in which the terminal periodically transmits a channel measurement result every time determined by the timer. The two methods transmit channel measurement results according to discrimination criteria of events or periods, respectively.

However, simply determining whether to transmit based on the primary determination result may cause signaling overhead. For example, according to the periodic report, even when the base station does not require the channel measurement result, the terminal may continue to transmit the channel measurement result. Unnecessary reporting may cause waste of radio resources.

There is a need for a method for performing a measurement procedure to efficiently use radio resources while reducing signaling load.

An object of the present invention is to provide a method for transmitting a channel measurement result by checking whether the channel measurement result satisfies a plurality of determination conditions.

The present invention provides a method for transmitting a channel measurement result, which is a measurement result of a channel state, in a wireless communication system. The terminal prepares the channel measurement result. The terminal checks whether the channel measurement result satisfies an event condition at regular intervals and transmits the channel measurement result when the event condition is satisfied.

A method of transmitting channel measurement results in a wireless communication system is provided. The terminal receives a measurement control message including a measurement period for the channel measurement result and an event condition which is a condition for transmitting the channel measurement result. The terminal checks whether the channel measurement result satisfies the event condition at each measurement period, and transmits the channel measurement result to the network when the event condition is satisfied.

A method of transmitting channel measurement results in a wireless communication system is provided. The terminal checks whether the first condition for transmitting the channel measurement result is satisfied. The terminal checks whether the second condition for transmitting the channel measurement result is satisfied when the first condition is satisfied, and transmits the channel measurement result when the second condition is satisfied.

In a wireless communication system, a base station provides a method of receiving a channel measurement result, which is a measurement result of a channel state. The channel measurement result is received from the terminal, the channel measurement result is determined whether the event condition is satisfied, and a message regarding whether to transmit the channel measurement result is transmitted in the next period.

In order for the terminal to report the channel measurement result to the network, a method of mixing two concepts, an event and a period, is used. By using the secondary discrimination method with flexible characteristics, it is possible to reduce the signaling load for channel measurement result reporting and to efficiently use radio resources.

1 is a block diagram illustrating a wireless communication system. This may be a network structure of an Evolved-Universal Mobile Telecommunications System (E-UMTS). The E-UMTS system may be referred to as a Long Term Evolution (LTE) system. Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) includes a base station (BS) 20 that provides a control plane and a user plane.

The UE 10 may be fixed or mobile and may be called by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, and the like. The base station 20 generally refers to a fixed station that communicates with the terminal 10 and may be referred to by other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, and the like. Can be. One or more cells may exist in one base station 20. An interface for transmitting user traffic or control traffic may be used between the base stations 20. Hereinafter, downlink means communication from the base station 20 to the terminal 10, and uplink means communication from the terminal 10 to the base station 20.

The base stations 20 may be connected to each other through an X2 interface. The base station 20 is connected to an Evolved Packet Core (EPC), more specifically, a Mobility Management Entity (MME) / System Architecture Evolution (SAE) gateway 30 through the S1 interface. The S1 interface supports a many-to-many-relation between the base station 20 and the MME / SAE gateway 30.

2 is a block diagram illustrating a functional split between an E-UTRAN and an EPC.

Referring to FIG. 2, the hatched block represents a radio protocol layer and the empty block represents a functional entity of the control plane.

The base station performs the following functions. (1) Radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic resource allocation to a terminal RRM), (2) Internet Protocol (IP) header compression and encryption of user data streams, (3) routing of user plane data to SAE gateways, and (4) paging messages. Scheduling and transmission, (5) scheduling and transmission of broadcast information, and (6) measurement and measurement report setup for mobility and scheduling.

The MME performs the following functions. (1) distribution of paging messages to base stations, (2) Security Control, (3) Idle State Mobility Control, (4) SAE Bearer Control, (5) NAS (Non-Access) Stratum) Ciphering and Integrity Protection of Signaling.

The SAE gateway performs the following functions. (1) termination of user plane packets for paging, and (2) user plane switching to support terminal mobility.

Meanwhile, the layers of the radio interface protocol between the terminal and the network are based on the lower three layers of the Open System Interconnection (OSI) model, which is widely known in a communication system. , L2 (second layer), and L3 (third layer) can be divided. Among them, the physical layer belonging to the first layer provides an information transfer service using a physical channel, and is a radio resource control (RRC) layer located in the third layer. The role of controlling the radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the UE and the network.

3 is a block diagram illustrating a radio protocol architecture for a user plane. 4 is a block diagram illustrating a radio protocol structure for a control plane. This shows the structure of the air interface protocol between the terminal and the E-UTRAN. The data plane is a protocol stack for user data transmission, and the control plane is a protocol stack for control signal transmission.

3 and 4, a physical layer, which is a first layer, provides an information transfer service to a higher layer by using a physical channel. The physical layer is connected to the upper Media Access Control (MAC) layer through a transport channel, and data between the MAC layer and the physical layer moves through this transport channel. Data moves between physical layers between physical layers, that is, between physical layers of a transmitting side and a receiving side. The physical channel is modulated by an orthogonal frequency division multiplexing (OFDM) scheme, and may use time and frequency as radio resources.

The MAC layer of the second layer provides a service to a radio link control (RLC) layer, which is a higher layer, through a logical channel. The RLC layer of the second layer supports reliable data transmission. In the RLC layer, there are three operation modes according to a data transmission method: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). The AM RLC provides a bidirectional data transmission service, and supports retransmission when an RLC Protocol Data Unit (PDU) fails to transmit.

The Packet Data Convergence Protocol (PDCP) layer of the second layer contains relatively large and unnecessary control information in order to efficiently transmit packets in a wireless bandwidth having a low bandwidth when transmitting an Internet Protocol (IP) packet such as IPv4 or IPv6. Perform header compression to reduce the IP packet header size.

The radio resource control (RRC) layer of the third layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transport channels, and physical channels in connection with configuration, re-configuration, and release of radio bearers (RBs). RB means a service provided by the second layer for data transmission between the UE and the E-UTRAN. If there is an RRC connection (RRC Connection) between the RRC of the terminal and the RRC of the network, the terminal is in the RRC Connected Mode, otherwise it is in the RRC Idle Mode.

The non-access stratum (NAS) layer located above the RRC layer performs functions such as authentication, SAE bearer management, and security control.

The RRC layer defines various RRC procedures to exchange configuration information necessary for radio resource management. Most of the RRC procedures are used for the purpose of setting and controlling the function of the terminal. Among them, the measurement procedure provides various information necessary to support proper network management and resource allocation considering the wireless environment.

5 is an exemplary view illustrating a method of transmitting a channel measurement result according to an embodiment of the present invention.

Referring to FIG. 5, a check point is defined as a time-out for a timer for periodic reporting of channel measurement results. At the check point the timer is reset and restarted. The terminal receives an event condition from the network and checks whether the event condition is satisfied at the check point. If the event condition is satisfied, the terminal transmits the measurement result of the channel state to the network. If the condition is not satisfied, the terminal does not transmit the channel measurement result and waits for the next check point.

Channel measurement results are not periodically reported unconditionally, and channel measurement results are reported after checking whether a certain condition is satisfied. The signaling load can be reduced by reporting the channel measurement result only when both the first condition (period) and the second condition (event condition) are satisfied. This is called periodic event-triggered reporting because it is a combination of periodic and event triggering conditions.

Examples of event conditions that the network notifies the terminal may include the following examples. (1) If the amount of transmission power used when the terminal transmits data to the network is greater than a specific value, the channel measurement result may be transmitted to the network. (2) When the amount of transmit power used by the terminal to transmit data to the network is smaller than a specific value, the channel measurement result may be transmitted to the network. (3) If the received signal is smaller than the specified value, the channel measurement result can be transmitted to the network. (4) If the received signal is larger than the specified value, the channel measurement result can be transmitted to the network. (5) If the magnitude of the interference increases and the magnitude of the signal compared to the interference is smaller than a specific value, the channel measurement result can be transmitted to the network. (6) If the size of the interference is smaller and the size of the signal compared to the interference is larger than a specific value, the channel measurement result can be transmitted to the network. (7) If the bit error rate is greater than the specified value, the channel measurement result can be transmitted to the network. (8) If the bit error rate is smaller than the specified value, the channel measurement result can be transmitted to the network. (9) If the number of correctly decoded blocks is smaller than a specific value, the channel measurement result can be transmitted to the network. (10) If the number of correctly decoded blocks is larger than a specific value, the channel measurement result can be transmitted to the network. (11) If the data rate is smaller than the specified value, the channel measurement result can be transmitted to the network. (12) If the data rate is greater than the specified value, the channel measurement result can be transmitted to the network. (13) If the packet error rate is greater than a specific value, the channel measurement result can be transmitted to the network. (14) If the packet error rate is smaller than a specific value, the channel measurement result can be transmitted to the network. (15) If the latency is greater than a specific value, the channel measurement result can be transmitted to the network. (16) If the latency is smaller than a specific value, the channel measurement result may be transmitted to the network. The magnitudes of the received signals for the serving cell and neighboring cells can be compared. (17) When the received signal is larger than the received signal of the serving cell in any one of the neighboring cells, the terminal may transmit the channel measurement result to the network. (18) If the average value of the received signals of the neighboring cells is larger than the received signal of the serving cell, the channel measurement result can be transmitted to the network. (19) When the difference between the two measured values is smaller than a specific value by comparing the magnitude of the received signal of one cell and the serving cell among neighboring cells, the channel measurement result may be transmitted to the network. (20) When the difference between the two measured values is smaller than a specific value by comparing the average value of the received signals of the neighboring cells with the magnitude of the received signal of the serving cell, the channel measurement result may be transmitted to the network. (21) When the cell having the best state among the neighboring cells is changed or the serving cell is changed, the channel measurement result can be transmitted. (22) If the channel measurement result to be transmitted from the current check point is the same as the channel measurement result transmitted from the previous check point, the channel measurement result is not transmitted. Instead, the two measurement results are different or the difference between the two measurement values is specified. If it is larger than the value, channel measurement result can be transmitted. (23) Transmission Time Interval (TTI) value, coding rate, number of cyclic redundancy check (CRC) bits, rate matching (rate), which determine semi-static attributes of channel components The channel measurement result can be transmitted to the base station when the network meets the criteria specified by the specific value. If the coding rate or the number of CRC bits applied in the current connection state is larger or smaller than a specific value, the channel measurement result may be transmitted to the network. (24) It is possible to determine the transmission of measurement results by creating a new condition combining the above mentioned conditions.

The specific value used in the event condition checking process may be a value that the network notifies the terminal or a value determined by internal calculation of the terminal.

6 is a flowchart illustrating a method of transmitting a channel measurement result according to an embodiment of the present invention.

Referring to FIG. 6, the network transmits measurement control information to a terminal through a measurement control message in a connected state (S610).

From the measurement control information, whether it is a periodic report, an event triggered report, or a periodic event triggered report is checked to determine whether the condition is satisfied accordingly (S620). When the condition is satisfied, the channel measurement result is transmitted to the network (S630).

The network transmits measurement control information to the terminal through a measurement control message. The terminal reports a measurement result to a network according to a predetermined measurement method while performing a measurement procedure based on measurement control information. The measurement control information may be delivered to the terminal through another path according to the RRC mode of the terminal. The UE in the RRC idle mode obtains information by receiving a System Information Block (SIB) # 11 transmitted through a broadcast channel (BCH), and the UE in the CELL_FACH, CELL_PCH, and URA_PCH states is measured using the SIB # 12. Control information can be received. When the UE is in the CELL_DCH state, the UE may receive a measurement control message through a dedicated control channel (DCCH).

Information included in the measurement control message may be shown in Table 1 below.

Information Explanation 1.Message Type Type of measurement control message 2. UE Information Elements   2-1. UE Transaction Identifier Transaction identification number   2-2. Integrity Check Info Message Authentication Code, RRC Message Sequence Number 3. Measurement Information Elements   3-1. Measurement identity Measurement identification number   3-2. Measurement command Setup / Modification / Release   3-3. Measurement Reporting Mode     3-3-1. Measurement Report Transfer Mode RLC mode (UM RLC or AM RLC)     3-3-2. Reporting Mode Periodical Reporting / Event Trigger Reporting / Periodical Event-Triggered Reporting   3-4. Report Criteria  See Table 2 4. Physical Channel Information Elements DPCH Compressed Mode Status Info Compressed Mode Status Information Required to Perform Inter-frequency Measurements and Inter-RAT (Radio Access Technology) Measurements

About Report Criteria Explanation Measurement Reporting Criteria Information pertaining to incident trigger report Periodical Reporting Criteria Information pertaining to periodic report   Amount of Reporting Report count   Reporting Interval Measuring cycle Periodical Event-Triggered Reporting Criteria Information pertaining to periodic event-causing report   Amount of Reporting Report count   Reporting Interval Measuring cycle   Event Identity Identifiers related to incident conditions   Triggering Condition Cell set causing the event No reporting No data (used when the measurement is applied as an additional measurement for another measurement)

When the reporting mode is periodic event triggered reporting, the measurement control information includes information about the measurement cycle and event conditions. The measurement procedure of the terminal of the base station is controlled through the measurement control message.

7 is an exemplary view illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention. This reflects the current check point to determine whether it is necessary to perform the process of checking whether the channel measurement result satisfies the event condition at the next check point.

Referring to FIG. 7, at the first check point, the terminal checks whether the channel measurement result satisfies an event condition. As a result of the check, if the event condition is satisfied, the terminal transmits the channel measurement result to the network. Then, it is determined whether confirmation is required at the next confirmation point.

If confirmation is required at the next confirmation point, the terminal confirms whether the event condition is satisfied using the channel measurement result at the second confirmation point. As a result of the check, if the condition is satisfied, the terminal transmits the channel measurement result to the network. The next checkpoint will determine whether a check is needed. Here, the case where confirmation is not required at the third confirmation point but confirmation at the fourth confirmation point is illustrated.

Since it is determined that the event check process is not necessary at the third check point, the terminal does not undergo a separate check process at the third check point.

At the fourth check point, the terminal checks whether the event condition is satisfied using the channel measurement result. If the event condition is confirmed and the condition is not satisfied, the channel measurement result is not transmitted and the terminal waits for the next check point.

This process is effective when it is determined that there is no significant change in the channel state during the next period as a result of checking the current channel state. For example, when the reception signal of the serving cell is larger than the reception signal of neighboring cells by more than a specific value, it is determined that there is no large cell change in the serving cell. In addition, judgment can be made using the above-mentioned event conditions.

If the channel measurement result is not transmitted to the network at a specific time point, the terminal may inform the network of the fact before the specific time point. The terminal may inform the network of the fact using an RRC message, a MAC message, or an indicator of a physical layer. After recognizing the fact through the terminal, the network may allocate an uplink radio resource allocated for reporting of the measurement result of the terminal to another terminal at the specific time point. Therefore, efficient radio resource management is possible.

8 is an exemplary view showing a method of transmitting a channel measurement result according to another embodiment of the present invention. The base station performs a process of checking whether the channel measurement result satisfies the event condition.

Referring to FIG. 8, the terminal basically prepares to report a channel measurement result every cycle. It is assumed that the terminal and the base station know each other through presharing with respect to the period information.

The base station receiving the first channel measurement result at the first check point determines whether the channel measurement result is necessary at the next check point using the received channel measurement result. In this case, it is determined that the channel measurement result is unnecessary at the next check point. The base station informs the terminal that it is not necessary to report the channel measurement result at the second check point. The terminal does not transmit the channel measurement result for the second check point to the base station.

At the third check point, the terminal transmits the channel measurement result to the base station. The base station receiving the third channel measurement result determines whether the channel measurement result is necessary at the next check point using the received channel measurement result.

At the fourth check point, the terminal transmits the channel measurement result to the base station. The base station receiving the fourth channel measurement result determines whether the channel measurement result is necessary at the next check point using the received channel measurement result.

If the base station says that it is not necessary to report the channel measurement result at the fifth check point, the terminal does not report the channel measurement result at the fifth check point.

If the terminal does not receive any instructions from the base station, reports the channel measurement results to the base station according to a given reporting method. If the base station informs that it is not necessary to report the channel measurement result for a specific check point (one or multiple), the terminal does not report the channel measurement result.

All of the above functions may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), or the like according to software or program code coded to perform the function. The design, development and implementation of the code will be apparent to those skilled in the art based on the description of the present invention.

Although the present invention has been described above with reference to the embodiments, it will be apparent to those skilled in the art that the present invention may be modified and changed in various ways without departing from the spirit and scope of the present invention. I can understand. Therefore, the present invention is not limited to the above-described embodiment, and the present invention will include all embodiments within the scope of the following claims.

1 is a block diagram illustrating a wireless communication system.

2 is a block diagram illustrating a functional split between an E-UTRAN and an EPC.

3 is a block diagram illustrating a radio protocol structure for a user plane.

4 is a block diagram illustrating a radio protocol architecture for a control plane.

5 is an exemplary view illustrating a method of transmitting a channel measurement result according to an embodiment of the present invention.

6 is a flowchart illustrating a method of transmitting a channel measurement result according to an embodiment of the present invention.

7 is an exemplary view illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

8 is an exemplary view showing a method of transmitting a channel measurement result according to another embodiment of the present invention.

Claims (7)

In a method for transmitting a channel measurement result which is a measurement result of the channel state in the wireless communication system, Preparing the channel measurement result; And Checking whether the channel measurement result satisfies an event condition at a predetermined period, and transmitting the channel measurement result when the event condition is satisfied. The method of claim 1, Determining whether to transmit the channel measurement result in a next period when the event condition is satisfied. The method of claim 1, And receiving information on whether to transmit the channel measurement result in a next period after transmitting the channel measurement result. In a method for transmitting a channel measurement result in a terminal in a wireless communication system, Receiving a measurement control message including a measurement period for the channel measurement result and an event condition which is a condition for transmitting the channel measurement result; And Checking whether the channel measurement result satisfies the event condition at each measurement period, and transmitting the channel measurement result when the event condition is satisfied. In the method for transmitting the channel measurement results in a wireless communication system, Confirming whether a first condition for transmitting the channel measurement result is satisfied; And Checking whether the second condition for transmitting the channel measurement result is satisfied when the first condition is satisfied, and transmitting the channel measurement result when the second condition is satisfied. The method of claim 5, wherein Receiving information about the first condition and the second condition from a base station. In the wireless communication system, a base station for receiving a channel measurement result that is a measurement result of the channel state, Receiving the channel measurement result from a terminal; And And determining whether the channel measurement result satisfies an event condition and transmitting a message on whether to transmit the channel measurement result in a next period.

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