KR20110014088A - Apparatus and method for configuring radio connection - Google Patents

Abstract

PURPOSE: A wireless connection setting apparatus and a method thereof, capable of transmitting an RRC connection request message from a multi component multicarrier system are provided to select necessary element carrier wave to establish the radio link. CONSTITUTION: A terminal receives distribution information through a first element carrier wave from a base station(S800). The terminal selects the second element carrier wave to the base station based on the distributed information(S805). The terminal performs the radio link through a second element carrier wave(S815, S820). The distributed information includes a probability factor about the multi-component carrier wave. The second element carrier wave is selected based on the probability element.

Description

Apparatus and method for establishing a wireless connection in a multi-element carrier system {APPARATUS AND METHOD FOR CONFIGURING RADIO CONNECTION}

The present invention relates to wireless communication, and more particularly, to an apparatus and method for setting a wireless connection in a multi-element carrier system.

Wireless communication systems are widely deployed to provide various kinds of communication services such as voice and data. In general, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency (SC-FDMA). division multiple access) system.

In a typical wireless communication system, even though the bandwidth between uplink and downlink is set differently, only one carrier is considered. In the 3rd Generation Partnership Project (3GPP) long term evolution (LTE), based on a single carrier, the number of carriers constituting uplink and downlink is one, and the bandwidth of the uplink and the downlink are generally symmetrical to each other. to be. However, frequency allocation of large bandwidths is not easy except in some regions of the world. Therefore, a technique for efficiently using fragmented small bands is a technique for spectral aggregation that combines a plurality of physically non-continuous bands in the frequency domain to produce the same effect as using a logically large band. Spectrum Aggregation technology is being developed. Spectrum aggregation includes, for example, 3GPP LTE, which supports bandwidths of up to 20 MHz, but uses multiple carriers to support 100 MHz of system bandwidth, and a technique for allocating asymmetric bandwidth between uplink and downlink. .

Meanwhile, the terminal is in a radio resource control (RRC) connected mode or idle mode. When the terminal is in the RRC connection mode, the terminal and the base station may be connected to the radio link by transmitting an RRC connection request message to the base station at any time when the radio link is in a connected state and in the idle mode. .

However, in the multi-component carrier system, which component carrier is used to transmit the RRC connection request message has not been determined yet. In addition, when a plurality of UEs perform the RRC connection request only through a specific CC having a very good channel state, overhead may occur due to excessive uplink transmission to a specific CC. Accordingly, there is a need for an apparatus and method for establishing a wireless connection by appropriately distributing the component carriers used in the wireless connection.

An object of the present invention is to provide an apparatus and method for setting a wireless connection in a multi-component carrier system.

Another object of the present invention is to provide a method for selecting a component carrier required to establish a radio connection in a multi-component carrier system.

According to an aspect of the present invention, there is provided a method for setting a wireless connection by a terminal in a multi-component carrier system. The method comprises receiving distribution information from a base station via a first component carrier, selecting a second component carrier to be used for wireless connection with the base station based on the distribution information, and the second component And performing a wireless connection through the component carrier.

According to another aspect of the present invention, there is provided a method of setting up a wireless connection by a base station in a multi-component carrier system. The method includes transmitting distributed information to a terminal through a first downlink component carrier, and receiving a radio connection request message from the terminal through a second uplink component carrier selected based on the distributed information. It is characterized by.

According to another aspect of the present invention, there is provided an apparatus for setting a wireless connection in a multi-component carrier system. The apparatus of claim 1, wherein the apparatus receives distributed information including probability elements required for selecting a component carrier to be used for a wireless connection. A component carrier selecting unit for selecting a component carrier to be used for the wireless connection by comparing the probability element with a randomly generated test value, and a wireless connection request message transmitting unit transmitting a wireless connection request message through the selected component carrier It is characterized by.

In a system supporting a plurality of component carriers combined by carrier aggregation, a terminal selects one carrier based on distributed information provided from a specific carrier (or cell), and transmits an RRC connection request message through the selected carrier. As a result, the overhead problem caused by biasing the RRC connection request message on a specific carrier can be solved.

1 shows a wireless communication system.
2 is an explanatory diagram illustrating the same intra-band contiguous carrier aggregation.
3 is an explanatory diagram illustrating the same in-band non-contiguous carrier aggregation.
4 is an explanatory diagram illustrating the same inter-band carrier aggregation.
5 shows an example of a protocol structure for supporting multiple carriers.
6 shows an example of a frame structure for multi-carrier operation.
FIG. 7 illustrates linkage between a downlink component carrier and an uplink component carrier in a multi-carrier system.
8 is a flowchart illustrating a method of setting up a wireless connection in a multi-component carrier system according to an embodiment of the present invention.
9 is a flowchart illustrating a method of selecting a CC for wireless connection according to an embodiment of the present invention.
10 is a flowchart illustrating a method of selecting a CC for wireless connection according to another embodiment of the present invention.
11 is a block diagram illustrating another apparatus for establishing a wireless connection according to an embodiment of the present invention.

Hereinafter, some embodiments will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the embodiments of the present specification, when it is determined that a detailed description of a related well-known configuration or function may obscure the gist of the present specification, the detailed description thereof will be omitted.

In addition, in describing the component of this specification, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but between components It will be understood that may be "connected", "coupled" or "connected".

In addition, the present specification describes a wireless communication network, the operation performed in the wireless communication network is performed in the process of controlling the network and transmitting data in the system (for example, the base station) that is in charge of the wireless communication network, or the corresponding wireless Work may be done at the terminal coupled to the network.

1 shows a wireless communication system.

Referring to FIG. 1, the wireless communication system 10 is widely deployed to provide various communication services such as voice and packet data.

The wireless communication system 10 includes at least one base station (BS) 11. Each base station 11 provides a communication service for a specific geographic area (generally called a cell) 15a, 15b, 15c. The cell may again be divided into multiple regions (referred to as sectors).

The mobile station (MS) 12 may be fixed or mobile, and may include a user equipment (UE), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, and a PDA. (personal digital assistant), wireless modem (wireless modem), a handheld device (handheld device) may be called other terms.

The base station 11 generally refers to a fixed station communicating with the terminal 12, and may be referred to as other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, and the like. have. The cell should be interpreted in a comprehensive sense of a part of the area covered by the base station 11 and encompasses various coverage areas such as megacells, macrocells, microcells, picocells and femtocells.

In the following, downlink means communication from the base station 11 to the terminal 12, and uplink means communication from the terminal 12 to the base station 11. In downlink, the transmitter may be part of the base station 11 and the receiver may be part of the terminal 12.

In uplink, the transmitter may be part of the terminal 12 and the receiver may be part of the base station 11.

There is no limitation on the multiple access scheme applied to the wireless communication system. Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA (SC-FDMA), OFDM-FDMA, OFDM-TDMA For example, various multiple access schemes such as OFDM-CDMA may be used. A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

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) reference model, which is widely known in communication systems. (Second layer) and L3 (third layer), wherein a physical layer belonging to the first layer provides an information transfer service using a physical channel, and a third layer. The radio resource control layer (hereinafter referred to as RRC) layer located in the layer plays a role of controlling radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the network.

The physical layer, which is the first layer, provides an information transfer service to an upper layer by using a physical channel. The physical layer is connected to the upper medium access control layer through a transport channel, and data between the medium access control layer and the physical layer moves through the transport channel. Then, data is moved between different physical layers, that is, between physical layers of a transmitting side and a receiving side through physical channels. The physical channel is modulated by an orthogonal frequency division multiplexing (OFDM) scheme and utilizes time and frequency as radio resources.

Medium access control (hereinafter referred to as MAC) of the second layer provides a service to a radio link control layer, which is a higher layer, through a logical channel. The radio link control layer (hereinafter referred to as RLC) layer of the second layer supports reliable data transmission. The functionality of the RLC layer may be implemented as a functional block inside the MAC. In this case, the RLC layer may not exist. The PDCP layer of the second layer is a header compression that reduces the IP packet header size, which is relatively large and contains unnecessary control information, for efficient transmission in a low bandwidth wireless section when transmitting an IP packet such as IPv4 or IPv6. Compression) function.

The radio resource control layer (hereinafter referred to as RRC) layer located in the third layer is defined only in the control plane, and the configuration and re-configuration of the radio bearer (abbreviated as RB) are performed. It is responsible for the control of logical channels, transport channels, and physical channels in association with and release. In this case, RB means a service provided by the second layer for data transmission between the terminal and the UTRAN. If there is an RRC connection (RRC Connection) between the RRC of the terminal and the RRC layer of the wireless network, the terminal is in the RRC connected mode (Connected Mode), otherwise it is in the RRC idle mode (Idle Mode).

The NAS (Non-Access Stratum) layer located above the RRC layer performs functions such as session management and mobility management.

Carrier aggregation (CA) supports a plurality of carriers, also referred to as spectrum aggregation or bandwidth aggregation. Individual unit carriers bound by carrier aggregation are called component carriers (CC). Each CC is defined by a bandwidth and a center frequency. Carrier aggregation is introduced to support increased throughput, to prevent cost increase due to the introduction of wideband radio frequency (RF) devices, and to ensure compatibility with existing systems.

For example, if five CCs are allocated as granularity in a carrier unit having a 5 MHz bandwidth, a bandwidth of up to 20 MHz may be supported.

Carrier aggregation includes intra-band contiguous carrier aggregation as shown in FIG. 2, intra-band non-contiguous carrier aggregation as shown in FIG. 3, and inter-band carrier as shown in FIG. Can be divided into aggregates.

First, referring to FIG. 2, in-band adjacent carrier aggregation is performed between consecutive CCs in the same band. For example, the aggregated CCs CC # 1, CC # 2, CC # 3, ..., CC #N are all adjacent.

Referring to FIG. 3, in-band non-adjacent carrier aggregation is achieved between discrete CCs. For example, the aggregated CCs CC # 1 and CC # 2 are spaced apart from each other by a specific frequency.

Referring to FIG. 4, when a plurality of CCs exist, one or more CCs are aggregated on different frequency bands. For example, CC # 1, which are aggregated CCs, exist in band # 1, and CC # 2 exists in band # 2.

The number of carriers aggregated between the downlink and the uplink may be set differently. The case where the number of downlink CCs and the number of uplink CCs are the same is called symmetric aggregation, and when the number is different, it is called asymmetric aggregation.

In addition, the size (ie bandwidth) of the CCs may be different. For example, assuming that 5 CCs are used for a 70 MHz band configuration, 5 MHz CC (carrier # 0) + 20 MHz CC (carrier # 1) + 20 MHz CC (carrier # 2) + 20 MHz CC (carrier # 3) It may be configured as + 5MHz CC (carrier # 4).

Hereinafter, a multiple carrier system refers to a system supporting carrier aggregation. Adjacent carrier aggregation and / or non-adjacent carrier aggregation may be used in a multi-carrier system, and either symmetric aggregation or asymmetric aggregation may be used.

5 shows an example of a protocol structure for supporting multiple carriers.

Referring to FIG. 5, the common medium access control (MAC) entity 510 manages a physical layer 520 using a plurality of carriers. The MAC management message transmitted on a specific carrier may be applied to other carriers. That is, the MAC management message is a message capable of controlling other carriers including the specific carrier. The physical layer 520 may operate in a time division duplex (TDD) and / or a frequency division duplex (FDD).

There are several physical control channels used in the physical layer 520. A physical downlink control channel (PDCCH) for transmitting physical control information is a HARQ (hybrid automatic repeat) associated with a resource allocation of a paging channel (PCH) and a downlink shared channel (DL-SCH) and DL-SCH to a UE. request) Provides information. The PDCCH may carry an uplink grant informing the UE of resource allocation of uplink transmission.

The physical control format indicator channel (PCFICH) informs the UE of the number of OFDM symbols used for PDCCHs and is transmitted every subframe. PHICH (physical Hybrid ARQ Indicator Channel) carries a HARQ ACK / NAK signal in response to uplink transmission. Physical uplink control channel (PUCCH) carries uplink control information such as HARQ ACK / NAK, scheduling request, and CQI for downlink transmission. Physical uplink shared channel (PUSCH) carries an uplink shared channel (UL-SCH).

6 shows an example of a frame structure for multi-carrier operation.

Referring to FIG. 6, a radio frame includes 10 subframes. The subframe includes a plurality of OFDM symbols. Each CC may have its own control channel (eg, PDCCH). CCs may or may not be adjacent to each other. The terminal may support one or more CCs according to its capability.

The CC may be divided into a fully configured CC and a partially configured CC according to directionality. The preconfigured CC refers to a carrier capable of transmitting and / or receiving all control signals and data on a bidirectional carrier, and the partial set CC refers to a carrier capable of transmitting only downlink data on a unidirectional carrier. The partially configured CC may be mainly used for a multicast and broadcast service (MBS) and / or a single frequency network (SFN).

CC may be divided into Primary Component Carrier (PCC) and Secondary Component Carrier (SCC) according to activation. PCC is always active carrier, SCC is a carrier that is activated / deactivated according to a specific condition.

Activation refers to the transmission or reception of traffic data being made or in a ready state. Deactivation means that transmission or reception of traffic data is impossible, and measurement or transmission of minimum information is possible.

The terminal may use only one PCC, or may use one or more SCCs together with the PCC. The terminal may be assigned a PCC and / or SCC from the base station. The PCC may be a preset carrier file, and is a carrier to which main control information is exchanged between the base station and the terminal. The SCC may be a preset carrier or a partially configured carrier file, and is a carrier assigned according to a request of a terminal or an indication of a base station. The PCC may be used for network entry of the terminal and / or allocation of the SCC. The PCC may be selected from among preset carriers rather than being fixed to a specific carrier. The carrier set to SCC may also be changed to PCC.

7 illustrates a link between a downlink component carrier and an uplink component carrier in a multi-carrier system.

Referring to FIG. 7, in downlink, downlink component carriers (hereinafter, referred to as DL CCs) D1, D2, and D2 are aggregated, and in uplink, uplink component carriers (hereinafter, referred to as UL CCs) U1, U2, and U3 are represented. Are concentrated. Where Di is an index of DL CC and Ui is an index of UL CC (i = 1, 2, 3). At least one DL CC is a PCC and the rest is an SCC. Similarly, at least one UL CC is a PCC and the rest are SCCs. For example, D1 and U1 are PCCs, and D2, U2, D3, and U3 are SCCs.

In the FDD system, the DL CC and the UL CC are configured to be connected 1: 1, and D1 is linked with U1, D2 is U2, and D3 is 1: 1 with U3. The terminal links the DL CCs and the UL CC through system information transmitted through a logical channel BCCH or a terminal dedicated RRC message transmitted by a DCCH. Each link may be set cell specific or UE specific.

An example of an UL CC linked to a DL CC is as follows.

1) a UL CC to which the terminal transmits ACK / NACK information on data transmitted by the base station through the DL CC,

2) a DL CC to which the base station transmits ACK / NACK information with respect to data transmitted by the terminal through the UL CC,

3) when the UE, which starts the random access procedure, receives a random access preamble (RAP) transmitted through the UL CC, the DL CC to transmit a response thereto;

4) When the base station transmits uplink control information through the DL CC, it is a UL CC to which the uplink control information is applied.

7 illustrates only a 1: 1 link between a DL CC and an UL CC, but a link of 1: n or n: 1 may also be established. In addition, the index of the component carrier does not correspond to the order of the component carrier or the position of the frequency band of the component carrier.

In a multi-component carrier system, each idle terminal can select a specific CC or cell to establish a radio connection. For example, when the UE establishes a radio connection through cell 2 of CC1, it may be said that the radio connection is established through CC1 or may be said to be established through cell 2. Hereinafter, for the sake of consistency of the description, the radio connection is said to be set at the CC level.

According to the introduction of the multi-component carrier, the radio connection may be configured through one specific CC selected from among several CCs. The idle terminal attempts a wireless connection by transmitting a radio connection message to a base station through a UL CC for radio connection.

However, it is assumed that each idle terminal measures the channel state for a plurality of CCs, and selects the CC having the best channel state as a CC for wireless connection. In this case, many idle terminals will select a CC having a relatively good channel state as a CC for wireless connection, and the many idle terminals will transmit a radio connection request message through the selected CC for wireless connection. That is, a phenomenon in which the radio connection request message is biased toward a specific CC occurs. This is true even when the idle terminal selects or reselects a CC having a high priority as a CC for radio connection according to the priority of a frequency designated by the base station. Therefore, there is a need for an apparatus and a method capable of uniformly distributing each idle terminal to a specific CC and evenly distributing it to all CCs during a wireless connection.

Hereinafter, a specific UL CC to be used by the idle terminal to establish a radio connection is called UL CC for radio connection (UL CC), and the DL CC linked to the UL CC for radio connection is called DL CC for radio connection. do. The UL CC for wireless connection and the DL CC for wireless connection are collectively called CC for wireless connection.

8 is a flowchart illustrating a method of setting up a wireless connection in a multi-component carrier system according to an embodiment of the present invention.

Referring to FIG. 8, it is assumed that the base station allocates CCs CC1, CC2, and CC3 to the UE. CC1, CC2, and CC3 are aggregated carriers. Each CC consists of a DL CC and an UL CC linked to the DL CC.

The terminal is a dormant terminal and is in a state where a wireless connection may be established through CC2 of the three CCs. However, there is a possibility that a plurality of terminals other than the terminal attempts a wireless connection through CC2. Therefore, the base station transmits distribution information to the terminal to increase the probability that the terminal attempts a wireless connection through another CC (S800). The distribution information is transmitted through DL CC2.

The distributed information is control information necessary to determine a CC for wireless connection for the terminal. The distribution information includes information about a probability factor and a CC which are probabilistic criteria for determining a CC for wireless connection. The probability component may have a specific value for each aggregated carrier or may be one value common to the aggregated carrier. The information about the CC includes an identifier of the aggregated carrier.

The distributed information may be transmitted through a broadcast control channel (BCCH) or a dedicated control channel (DCCH) on CC2. When the distributed information is transmitted through a broadcast control channel, the distributed information may be transmitted as system information.

When the distributed information is transmitted through a dedicated control channel, the distributed information may be transmitted in an RRC connection request reject message or an RRC connection release message. The distribution information included in the RRC connection rejection message means that the base station rejects the RRC connection request of the terminal through the specific CC and at the same time reselects another CC as a radio connection CC. This is also the case when the distribution information is included in the RRC connection rejection message.

The terminal selects a CC for wireless connection from among the aggregated carriers based on the distributed information (S805). Selecting a specific CC as a CC for wireless connection means that the specific CC has passed a selection test using the distributed information. In the example of FIG. 8, it is assumed that CC1 is selected as a CC for wireless connection. However, since the CC for the wireless connection does not necessarily need to be different from the CC in which the distributed information is transmitted, it may be CC2, and one or more CCs may be selected as the CC for the wireless connection.

The terminal enters connection ready (S810). In this case, the connection preparation means a state in which the terminal may receive downlink from the base station or transmit uplink to the base station. Alternatively, the connection preparation may mean that the terminal camps on the wireless connection CC.

The terminal transmits a radio connection request message through the selected radio connection CC as necessary (S815). The radio connection request message is transmitted through a UL CC of the selected radio connection CC. The wireless connection may be an RRC connection. In this case, the radio connection request message is an RRC connection request message. As a response to the radio connection request message, the base station transmits a radio connection permission message to the terminal (S820), thereby completing the radio connection setting through the selected radio connection CC (S825).

When selecting a CC to be used for a wireless connection based on the priority or the channel state measured by the UE, it is highly likely that only the CC having the excellent channel state is selected. However, using distributed information as in the present invention increases the probability of selecting different CCs for each wireless connection for each terminal, and as a result, it is possible to prevent a specific CC biasing of the terminal.

Hereinafter, a method of selecting a CC for wireless connection using a probability element will be described in detail.

9 is a flowchart illustrating a method of selecting a CC for wireless connection according to an embodiment of the present invention.

9, the terminal receives the distribution information from the base station (S900). The distributed information may be received through a broadcast control channel or a dedicated control channel.

The variance information includes a probability factor (PF). When three CCs are aggregated for the UE, such as CC1, CC2, and CC3, the probability factors exist for each CC. As shown in the table.

CC1 CC2 CC3 PF1 PF2 PF3

Referring to Table 1, each CC is given a specific probability factor. That is, the probability element for CC1 is PF1, the probability element for CC2 is PF2, and the probability element for CC3 is PF3. Here, 0 <PHi <N (i = 1, 2, 3), PFi <PF (i + 1), or PFi = PF (i + 1).

The terminal generates an arbitrary test value to be used in a selection test (S905). Here, the selection test is to determine whether a specific CC can be a CC for wireless connection. The test value is a value randomly generated by the terminal and is given as a value greater than 0 and less than or equal to the maximum value among the PF1, PF2, and PF3. For example, when PF1 = 0.3, PF2 = 0.7, and PF3 = 1, since the maximum value of the probability factor is 1, the terminal may generate a value greater than 0 and less than or equal to 1 as a test value. The random test value is a value uniquely determined for each terminal. Therefore, assuming that different test values are generated for each terminal, each terminal is more likely to select a different CC for wireless connection. That is, the likelihood that the terminal is distributed on a plurality of component carriers increases. As a result, the problem that the radio connection request message of each terminal is biased to a specific CC can be solved.

The terminal determines whether CCi passes the selection test (S910).

As an example of the selection test, the terminal passes only the CC corresponding to the minimum probability element among the probability elements larger than the test value in the selection test. For example, assume that PF1 = 0.3, PF2 = 0.7, and PF3 = 1, and the test value is 0.6. Values larger than the test value are PF2 = 0.7 and PF3 = 1, and since 0.7 is the minimum value, CC2 having a probability element of 0.7 passes the selection test. In the above example, if the test value is 0.2, since the minimum value is 0.3 as a probability element larger than 0.2, CC1 corresponding to PF1 passes the selection test.

As another example of the selection test, the terminal compares the probability factor PFi for any of CCi, CC2, CC3 with the test value, and if the PFi is greater than the test value, the terminal selects the CCi in the selection test. Pass. In the opposite case, the terminal does not pass the CCi in the selection test. For example, assume that PF1 = 0.3, PF2 = 0.7, and PF3 = 1, and the test value is 0.6. If the terminal randomly selects CC3, PF3 is greater than the test value, so CC3 passes in the selection test. On the other hand, when the terminal randomly selects CC1, since PF1 is smaller than the test value, CC1 is not passed in the selection test, and the terminal randomly repeats the selection test for another CC. Here, the probability factor may be a value common to all aggregated CCs. In this case as well, the terminal performs the selection test to select a CC for wireless connection.

As another example of the selection test, the terminal is a probability factor greater than the test value T calculated by the following equation, and may pass only the CC, which is the minimum value, in the selection test.

Here, ID is an identifier of the terminal, and includes an International Mobile Subscriber Identity (IMSI), a Cell-Radio Network Temporary Identifier (C-RNTI), a Temporary Mobile Subscriber Identity (TMSII), and the like. N is the maximum value of the probability element. Mod stands for modulo operation.

For example, let PF1 = 2, PF2 = 5, and PF3 = 8, and let ID = 35 of the terminal. Since N = 8, according to Equation 1, T = 35 Mod (8) = 3. As the probability factor greater than 3, since the minimum value is PF2 = 5, the terminal passes CC2 in the selection test.

If CCi is not passed in the selection test, the terminal performs the selection test on CC (i + 1) again (S915, S910). If CCi passes in the selection test, the terminal wirelessly connects CCi. It is determined as the CC (S920).

10 is a flowchart illustrating a method of selecting a CC for wireless connection according to another embodiment of the present invention.

Referring to FIG. 10, the terminal receives distribution information from the base station (S1000). The distributed information may be received through a broadcast control channel or a dedicated control channel.

The terminal generates an arbitrary test value to be used in the selection test (S1005). Here, the selection test is to determine whether a specific CC can be a CC for wireless connection. The test value is a value randomly generated by the terminal and is given as a value greater than 0 and less than or equal to the maximum value among the PF1, PF2, and PF3.

The terminal determines whether CCi passes the selection test (S1010). The selection test is as described in FIG. 9 above. If CCi is not passed in the selection test, the terminal performs the selection test on CC (i + 1) again (S1015 and S1010).

If the CCi is passed in the selection test, the terminal compares the channel state of the CCi with a threshold (S1020). The reference value is a minimum channel state for the CCi to be a CC for wireless connection. If the channel state is greater than or equal to the reference value, the terminal determines the CCi as a CC for wireless connection (S1025). On the other hand, if the channel state is less than the reference value, the terminal reselects the radio connection CC based on the channel state (S1030).

11 is a block diagram illustrating another apparatus for establishing a wireless connection according to an embodiment of the present invention.

Referring to FIG. 11, the multi-element carrier system includes a first radio connection setting device 1100 and a second radio connection setting device 1150. The first wireless connection setting device 1100 may be part of the terminal. The second wireless connection setting device 1150 may be part of the base station.

The first wireless connection setting device 1100 includes a distributed information receiving unit 1105, a CC selecting unit 1110 for wireless connection, and a wireless connection setting message transmitting unit 1115.

The distributed information receiver 1105 receives distributed information from the second wireless connection setting device 1150. The distributed information is control information necessary for the radio connection CC selecting unit 1110 to determine the radio connection CC. The distribution information includes information about a probability element and a CC which are probabilistic criteria for determining a CC for wireless connection. The probability component may have a specific value for each aggregated carrier or may be one value common to the aggregated carrier. The information about the CC includes an identifier of the aggregated carrier. The distributed information may be received through a broadcast control channel as system information, or may be received through a dedicated control channel as an RRC disconnection message / RRC disconnection message.

The CC selection unit 1110 for a wireless connection performs a selection test based on the probability elements included in the distributed information, and selects the CC passed in the selection test as the CC for the wireless connection. The selection test is performed in the same manner as described in FIG. 9.

The wireless connection setting message transmitter 1115 transmits a wireless connection setting message to the second wireless connection setting device 1150 through the CC for wireless connection selected by the CC for selecting the wireless connection 1110. The radio connection configuration message is a message generated at the RRC layer and may be an RRC connection configuration message.

The second wireless connection setting device 1150 includes a probability element generating unit 1155, a distributed information transmitting unit 1160, and a wireless connection setting message receiving unit 1165.

The probability element generator 1155 generates a specific probability element for each CC or generates a probability element common to all CCs. For example, the probability element generator 1155 generates a probability element 0.3 for CC1 and a probability element 0.8 for CC2. Alternatively, the probability element generator 1155 may generate a common probability element 0.5 for CC1 and CC2.

The distributed information transmitter 1160 generates distributed information including a probability element and transmits the distributed information to the first wireless connection setting apparatus 1100.

The wireless connection setting message receiving unit 1165 receives a wireless connection setting message from the first wireless connection setting device 1100.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (20)

In the multi-component carrier system, a method for setting up a wireless connection by a terminal,
Receiving distribution information from a base station via a first component carrier;
Selecting a second component carrier to be used for performing a wireless connection with the base station based on the distributed information; And
And performing a wireless connection through the second component carrier. The method of claim 1,
The scattering information includes a probability factor for each of the multi-component carriers, and the second component carrier is selected based on the probability factor. The method of claim 2,
The probability component is different for each of the multi-component carriers, the method of establishing a wireless connection. The method of claim 2,
And the probability component is common to the multi-component carrier. The method of claim 2,
And the second component carrier is selected by comparing the probability value with a test value randomly generated by the terminal. The method of claim 5, wherein
And the second component carrier is a component carrier corresponding to a minimum probability component among probability components larger than the test value. The method of claim 1,
The wireless connection is characterized in that the connection (connection) at the radio resource control (RRC) layer level, the connection method of the wireless connection. The method of claim 7, wherein
The performing of the radio connection may further include transmitting an RRC connection request message to the base station. The method of claim 1,
The distributed information is received through a broadcast control channel (BCCH), characterized in that for establishing a wireless connection. The method of claim 1,
The distributed information is received via a dedicated control channel (DCCH) dedicated to the terminal, the method of establishing a wireless connection. The method of claim 10,
The distributed information is included in an RRC disconnection message indicating that the RRC connection between the terminal and the base station is released, characterized in that for receiving a radio connection. The method of claim 10,
The distributed information is included in the RRC connection rejection message indicating that the RRC connection between the terminal and the base station is received, characterized in that the wireless connection establishment method. In a multi-component carrier system, a method of setting up a wireless connection by a base station,
Transmitting distributed information to a terminal through a first downlink component carrier; And
And receiving a radio connection request message from the terminal through a second uplink component carrier selected based on the distributed information. The method of claim 13,
And transmitting a radio connection permission message to the terminal through a second downlink component carrier linked with the second uplink component carrier. The method of claim 13,
Transmitting a radio connection rejection message including new distributed information through a second downlink component carrier linked to the second uplink component carrier to the terminal; And
And receiving a new radio connection request message from the terminal through a third uplink component carrier selected based on the new distributed information. In a device for setting a wireless connection in a multi-component carrier system,
A distributed information receiver for receiving distributed information including probability elements required for selecting a component carrier to be used for a wireless connection;
A component carrier selecting unit for wireless connection selecting a component carrier to be used for the wireless connection by comparing the probability element with a randomly generated test value; And
And a radio connection request message transmitter for transmitting a radio connection request message through the selected CC. 17. The method of claim 16,
The probability component is set differently for each of the multi-component carriers, and the probability component for the component carrier to be used for the radio connection is the minimum among the probability elements larger than the test value. 17. The method of claim 16,
The component carrier selecting unit for the radio connection may finally select the component carrier to be used for the radio connection by further considering the channel state for the component carrier selected by comparing the probability element with a randomly generated test value. Establishment of the connection. The method of claim 18,
And the distributed information receiver receives the distributed information through a broadcast control channel. The method of claim 18,
And the distributed information receiver receives the distributed information through a dedicated control channel.

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