WO2013165093A1 - Procédé et appareil de commande de groupe d'avance temporelle dans un système à multiples porteuses élémentaires - Google Patents

Procédé et appareil de commande de groupe d'avance temporelle dans un système à multiples porteuses élémentaires Download PDF

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Publication number
WO2013165093A1
WO2013165093A1 PCT/KR2013/002200 KR2013002200W WO2013165093A1 WO 2013165093 A1 WO2013165093 A1 WO 2013165093A1 KR 2013002200 W KR2013002200 W KR 2013002200W WO 2013165093 A1 WO2013165093 A1 WO 2013165093A1
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Prior art keywords
serving cell
random access
secondary serving
tag
base station
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PCT/KR2013/002200
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English (en)
Korean (ko)
Inventor
권기범
안재현
허강석
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주식회사 팬택
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Publication of WO2013165093A1 publication Critical patent/WO2013165093A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H04W56/0005—Synchronisation arrangements synchronizing of arrival of multiple uplinks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H04W56/001—Synchronization between nodes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0833—Random access procedures, e.g. with 4-step access
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/27—Transitions between radio resource control [RRC] states

Definitions

  • the present invention relates to wireless communications, and more particularly, to a method and apparatus for operating a time advance group in a multi-element carrier system.
  • the bandwidth between uplink and downlink is set differently, only one carrier is considered.
  • 3GPP 3rd Generation Partnership Project
  • LTE long term evolution
  • the number of carriers constituting uplink and downlink is one, and the uplink bandwidth and the downlink bandwidth are symmetrical to each other.
  • random access is performed using one carrier.
  • random access can be implemented through a plurality of component carriers.
  • the multi-component carrier system refers to a wireless communication system capable of supporting carrier aggregation.
  • Carrier aggregation is a technique for efficiently using fragmented small bands, such as using a logically large band by combining a plurality of physically continuous or non-continuous bands in the frequency domain. Is to make
  • the terminal goes through a random access procedure to access the network.
  • the random access procedure may be divided into a contention based random access procedure and a non-contention based random access procedure.
  • the biggest difference between the contention-based random access procedure and the non- contention-based random access procedure is whether a random access preamble is designated as dedicated to one UE.
  • contention means that two or more terminals competitively use a time / frequency / sequence resource set to access a base station so that the base station can use the plurality of terminals without allocating them to each terminal.
  • contention-based random access procedure since a terminal uses a randomly selected time / frequency resource and a random access preamble, there is a possibility of contention with another terminal other than the terminal.
  • the purpose of the UE to perform a random access process to the network may be an initial access (initial access), handover (handover), radio resource request (Sheduling Request), time advance (TA; timing advnaced).
  • An object of the present invention is to provide a method and apparatus for operating a timing advance group (TAG) in a terminal operating based on multiple uplink synchronization in a multi-component carrier system.
  • TAG timing advance group
  • An object of the present invention is to provide an apparatus and method for uplink synchronization in a multi-component carrier system.
  • Another technical problem of the present invention is to provide a method and apparatus for configuring a TAG when a timing advance timer (TAT) of the TAG expires.
  • TAT timing advance timer
  • Another technical problem of the present invention is a random access method when a TAG of a secondary serving cell is changed based on a radio resource control (RRC) connection reconfiguration procedure during a random access procedure in a secondary serving cell (SCell).
  • RRC radio resource control
  • Another technical problem of the present invention is to provide a method and apparatus for changing a secondary serving cell included in the newly added sTAG to an activated state when a second TAG is newly added based on an RRC connection reconfiguration procedure. .
  • a terminal for acquiring two or more different uplink syncs in a multi-component carrier system is provided.
  • the terminal is a medium access control (MAC) processor for controlling the transmission of a random access preamble used for obtaining a time advance value for uplink synchronization of a secondary serving cell (SCell), the random access preamble to the base station
  • a radio resource control (RRC) processing unit for determining a change of a TAG ID, wherein the MAC processing unit performs the random access procedure when a TAG ID for the secondary serving cell is changed while a random access procedure is performed on the secondary serving cell. Characterized in that it stops.
  • RRC radio resource control
  • a base station supporting a random access procedure in a multi-component carrier system is provided.
  • the base station is a MAC processor for controlling the transmission of the PDCCH order (order) and the random access response message indicating the start of the random access procedure used to obtain a time advance value for the synchronization of the uplink time of the secondary serving cell, random access Receiving unit for receiving a preamble from the terminal, RRC processing unit for generating the TAG configuration information indicating the change of the TAG ID for the secondary serving cell, and transmission for transmitting the PDCCH indication and random access response message and the TAG configuration information to the terminal And the MAC processing unit treats the random access procedure as stopped when the TAG ID for the secondary serving cell is changed while the random access procedure is in progress on the secondary serving cell.
  • the PDCCH indication may be transmitted.
  • a method for acquiring uplink synchronization by a terminal in a multi-component carrier system is provided.
  • receiving a PDCCH indication indicating a start of a random access procedure for synchronization of an uplink time of a secondary serving cell from a base station and providing TAG configuration information including a TAG ID for the secondary serving cell to the base station.
  • the sTAG can be reconfigured to an initial configuration, thereby simplifying the procedure and improving the reliability and stability of the communication.
  • the secondary serving cell changes the sTAG including the secondary serving cell during the random access procedure, the secondary serving cell can perform the random access procedure for the reconfigured sTAG without waiting for the random access procedure to be terminated. It can go faster.
  • the procedure is simplified and the random access procedure can be performed more quickly.
  • FIG. 1 shows a wireless communication system to which the present invention is applied.
  • FIG. 2 shows an example of a protocol structure for supporting a multi-component carrier to which the present invention is applied.
  • FIG. 3 shows an example of a frame structure for a multi-component carrier operation to which the present invention is applied.
  • FIG 4 shows linkage between a downlink component carrier and an uplink component carrier in a multi-component carrier system to which the present invention is applied.
  • FIG. 5 is a flowchart illustrating a procedure of obtaining a multi-time forward value according to an embodiment of the present invention.
  • FIG. 6 illustrates a process in which secondary serving cell configuration information and TAG configuration information are transmitted by one RRC connection reconfiguration procedure.
  • FIG. 7 is a flowchart illustrating a method of performing random access according to an embodiment of the present invention.
  • FIG. 8 is a flowchart illustrating an operation of a base station upon expiration of a TAT of an sTAG according to an embodiment of the present invention.
  • FIG. 9 is a flowchart illustrating an operation of a terminal when the TAT of an sTAG expires according to an embodiment of the present invention.
  • FIG. 10 is a flowchart illustrating an operation of a terminal when a TAT of sTAG expires during a random access procedure according to an embodiment of the present invention.
  • FIG. 11 is a flowchart illustrating operations of a terminal and a base station when a TAT of sTAG expires during a random access procedure according to an embodiment of the present invention.
  • FIG. 12 is a flowchart illustrating an operation of a terminal when the sTAG to which the secondary serving cell 1 belongs during the random access procedure is changed according to an embodiment of the present invention.
  • FIG. 13 is a flowchart illustrating operations of a terminal and a base station when an sTAG including the secondary serving cell is changed during a random access procedure on the secondary serving cell according to an embodiment of the present invention.
  • FIG. 14 is a flowchart illustrating an operation of a terminal when a secondary serving cell according to an embodiment of the present invention is reconfigured to sTAG for which uplink synchronization is not secured.
  • 15 is a flowchart illustrating operations of a terminal and a base station when a secondary serving cell is reconfigured with a newly added TAG according to an embodiment of the present invention.
  • FIG. 16 illustrates an operation of a terminal when a TAG is changed according to an embodiment of the present invention.
  • FIG. 17 illustrates an operation of a base station when a TAG is changed according to an embodiment of the present invention.
  • FIG. 18 is a block diagram illustrating a terminal and a base station according to an embodiment of the present invention.
  • 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.
  • FIG. 1 shows a wireless communication system to which the present invention is applied.
  • 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.
  • BS base station
  • Each base station 11 provides a communication service for specific cells 15a, 15b, and 15c.
  • the cell can in turn be divided into a number of regions (called sectors).
  • the user equipment (UE) 12 may be fixed or mobile, and may include a mobile station (MS), 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 may be called in other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, an femto base station, a home nodeB, a relay, and the like. .
  • eNB evolved-NodeB
  • BTS base transceiver system
  • 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.
  • 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.
  • the transmitter may be part of the base station 11 and the receiver may be part of the terminal 12.
  • the transmitter may be part of the terminal 12 and the receiver may be part of the base station 11.
  • CDMA Code Division Multiple Access
  • TDMA Time Division Multiple Access
  • FDMA Frequency Division Multiple Access
  • OFDMA Orthogonal Frequency Division Multiple Access
  • SC-FDMA Single Carrier-FDMA
  • OFDM-FDMA OFDM-FDMA
  • OFDM-TDMA OFDM-TDMA
  • various multiple access schemes such as OFDM-CDMA may be used.
  • the uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.
  • TDD time division duplex
  • FDD frequency division duplex
  • Carrier Aggregation supports a plurality of carriers, also referred to as spectrum aggregation or bandwidth aggregation.
  • Carrier aggregation is a technique for efficiently using fragmented small bands, such as using logically large bands by combining multiple physically continuous or non-continuous bands in the frequency domain. You can make The individual unit carriers bound by carrier aggregation are called component carriers (CC). Each component carrier 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 component carriers are allocated as granularity in a carrier unit having a 20 MHz bandwidth, a bandwidth of up to 100 MHz may be supported.
  • RF radio frequency
  • Carrier aggregation may be divided into contiguous carrier aggregation between continuous component carriers in the frequency domain and non-contiguous carrier aggregation between discontinuous component carriers.
  • the number of carriers aggregated between the downlink and the uplink may be set differently. The case where the number of downlink component carriers and the number of uplink component carriers are the same is called symmetric aggregation, and when the number is different, it is called asymmetric aggregation.
  • the size (ie, bandwidth) of component carriers may be different from each other. For example, assuming that 5 component carriers are used for the configuration of the 70 MHz band, a 5 MHz component carrier (carrier # 0) + 20 MHz component carrier (carrier # 1) + 20 MHz component carrier (carrier # 2) + 20 MHz component carrier (carrier # 3) + 5MHz component carrier (carrier # 4) may be configured.
  • a multiple component carrier system refers to a system including a terminal and a base station supporting carrier aggregation.
  • Adjacent carrier aggregation and / or non-adjacent carrier aggregation may be used in a multi-component carrier system, and either symmetric aggregation or asymmetric aggregation may be used.
  • FIG. 2 shows an example of a protocol structure for supporting a multi-component carrier to which the present invention is applied.
  • a medium access control (MAC) entity 210 manages a physical layer 220 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 220 may operate in a time division duplex (TDD) and / or a frequency division duplex (FDD).
  • TDD time division duplex
  • FDD frequency division duplex
  • PDCCH Physical Downlink Control Channel
  • DL-SCH Downlink Shared Channel
  • HARQ Hybrid Automatic Repeat Request
  • the PDCCH may carry an uplink grant informing the UE of resource allocation of uplink transmission.
  • the DL-SCH is mapped to a physical downlink shared channel (PDSCH).
  • 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
  • PHICH Physical Hybrid ARQ Indicator Channel
  • a physical uplink control channel (PUCCH) carries uplink control information such as a HARQ ACK / NACK signal, a scheduling request, and a CQI for downlink transmission.
  • PUSCH Physical Uplink Shared Channel
  • UL-SCH Uplink Shared Channel
  • PRACH Physical Random Access Channel
  • FIG. 3 shows an example of a frame structure for a multi-component carrier operation to which the present invention is applied.
  • one frame consists of 10 subframes.
  • the subframe may include a plurality of OFDM symbols on the time axis and at least one component carrier on the frequency axis.
  • Each CC may have its own control channel (eg, PDCCH).
  • Multi-component carriers may or may not be adjacent to each other.
  • the terminal may support one or more component carriers according to its capability.
  • the CC may be divided into a Primary Component Carrier (PCC) and a Secondary Component Carrier (SCC).
  • the terminal may use only one major carrier, or may use one or more subcomponent carriers together with the major carrier.
  • the terminal may be assigned a major carrier and / or sub-carrier carrier from the base station.
  • the CC may be represented by a cell or a serving cell.
  • a component carrier that is not explicitly expressed as a downlink CC or an uplink CC may include both a downlink component and an uplink component carrier or include only a downlink component carrier. Configured.
  • FIG 4 shows linkage between a downlink component carrier and an uplink component carrier in a multi-component carrier system to which the present invention is applied.
  • downlink component carriers D1, D2, and D3 are aggregated, and uplink component carriers U1, U2, and U3 are aggregated in uplink.
  • Di is an index of a downlink component carrier
  • At least one downlink component carrier is a major carrier wave, and the rest is a secondary component carrier.
  • at least one uplink component carrier is a major carrier wave and the rest are subcomponent carriers.
  • D1 and U1 are major carrier waves
  • D2, U2, D3 and U3 are subcomponent carriers.
  • the index of the major carrier may be set to 0, and one of the other natural numbers may be the index of the subcarrier.
  • the index of the downlink / uplink component carrier may be set to be the same as the index of the component carrier (or serving cell) including the corresponding downlink / uplink component carrier.
  • the index of the component carrier (or serving cell) including the corresponding downlink / uplink component carrier may be set to be the same as the index of the component carrier (or serving cell) including the corresponding downlink / uplink component carrier.
  • only the component carrier index or the subcarrier index may be set, and the uplink / uplink component carrier index included in the component carrier may not exist.
  • the downlink component carrier and the uplink component carrier may be configured to be 1: 1.
  • D1 may be connected to U1, D2 to U2, and D3 to U3 at 1: 1.
  • the terminal establishes a connection between the downlink component carriers and the uplink component carriers through system information transmitted by a logical channel BCCH or a terminal-specific RRC message transmitted by a DCCH.
  • This connection is called a system information block 1 (SIB1) connection or a system information block 2 (SIB2) connection.
  • SIB1 system information block 1
  • SIB2 system information block 2
  • Each connection configuration may be set cell specific or UE specific.
  • the major carrier may be cell-specific and the sub-carrier may be terminal-specific.
  • connection configuration of 1: n or n: 1 may also be established.
  • 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.
  • the primary serving cell refers to one serving cell that provides security input and NAS mobility information in an RRC establishment or reestablishment state.
  • at least one cell may be configured to form a set of serving cells together with the main serving cell, wherein the at least one cell is called a secondary serving cell.
  • the set of serving cells configured for one terminal may consist of only one main serving cell, or may consist of one main serving cell and at least one secondary serving cell.
  • the downlink component carrier corresponding to the main serving cell is called a DL PCC
  • the uplink component carrier corresponding to the main serving cell is called an UL PCC
  • the component carrier corresponding to the secondary serving cell is called a downlink sub-component carrier (DL SCC)
  • DL SCC downlink sub-component carrier
  • UL SCC uplink sub-component carrier
  • the communication between the terminal and the base station through the DL CC or the UL CC in the carrier system is a concept equivalent to the communication between the terminal and the base station through the serving cell.
  • transmitting a preamble on the UL CC may be regarded as a concept equivalent to transmitting the preamble on the primary serving cell or the secondary serving cell.
  • the terminal receiving the downlink information on the DL CC can be seen as a concept equivalent to receiving the downlink information on the primary serving cell or secondary serving cell.
  • the main serving cell and the secondary serving cell has the following characteristics.
  • the primary serving cell is used for transmission of the PUCCH.
  • the secondary serving cell may not transmit the PUCCH, but may transmit some control information of the information in the PUCCH through the PUSCH.
  • the main serving cell is always activated (activated), while the secondary serving cell is a carrier that is activated / deactivated according to a specific condition.
  • the specific condition may be a case where the activation / deactivation indicator of the base station is received or the deactivation timer in the terminal configured for each secondary serving cell expires.
  • Activation refers to the transmission or reception of traffic data being made or in a ready state. Deactivation is not possible to transmit or receive traffic data and control information for the traffic data, and measurement and reporting for generating downlink channel state information are not possible, but minimal measurement or transmission / reception of minimum information is possible.
  • a physical control format indication channel PCFICH
  • control format indicator channel indicating a region in which control information is transmitted through downlink of a corresponding serving cell and measurement of reference signal received power for path attenuation calculation and the like. control format indicator channel).
  • Radio link failure occurs when downlink performance is maintained below a threshold for more than a predetermined time or when the RACH has failed more than the threshold.
  • the main serving cell may be changed by a security key change or a handover procedure accompanying the RACH procedure.
  • contention resolution (CR) message only the PDCCH indicating the contention resolution message should be transmitted through the primary serving cell, and the contention resolution message transmitted through the PDSCH may be transmitted through the primary or secondary serving cell. have.
  • NAS non-access stratum
  • the main serving cell always consists of a pair of DL PCC and UL PCC.
  • a different CC may be set as a primary serving cell for each terminal.
  • RRC radio resource control
  • RRC signaling may be used to transmit system information of a dedicated secondary serving cell.
  • RRC connection reconfiguration procedure may be used as the RRC signaling.
  • the main serving cell is a PDCCH (for example, downlink allocation information allocated to a UE-specific search space) configured to transmit control information only to a specific terminal in an area for transmitting control information. Or uplink grant information) and a PDCCH (eg, a system allocated to a common search space (CSS) configured to transmit control information to all terminals in a cell or a plurality of terminals meeting specific conditions).
  • SI information
  • RAR random access response
  • TPC transmit power control
  • the secondary serving cell may be set only a terminal-specific search space. That is, since the terminal cannot identify the common search space through the secondary serving cell, the terminal cannot receive control information transmitted only through the common search space and data information indicated by the control information.
  • a secondary serving cell in which a common search space (CSS) may be defined may be defined, and the secondary serving cell is referred to as a special secondary serving cell (special SCell).
  • the special secondary serving cell is always configured as a scheduling cell during cross carrier scheduling.
  • the PUCCH configured in the PCell may be defined for the special secondary serving cell.
  • the PUCCH for the special secondary serving cell may be fixedly configured when the special secondary serving cell is configured, or the base station may be allocated (configured) or released by RRC signaling (RRC reconfiguration message) when the base station is reconfigured for the secondary secondary cell. have.
  • the PUCCH for the special secondary serving cell includes ACK / NACK information or channel quality information (CQI) of the secondary serving cells present in the corresponding sTAG, and as mentioned above, may be configured through RRC signaling by the base station. have.
  • CQI channel quality information
  • the base station may configure one special secondary serving cell of a plurality of secondary serving cells in the sTAG, or may not configure a special secondary serving cell.
  • the reason for not configuring the special secondary serving cell is because it is determined that CSS and PUCCH need not be set. For example, if it is determined that the contention-based random access procedure does not need to be performed in any secondary serving cell, or it is determined that the current capacity of the PUCCH of the primary serving cell is sufficient, it is not necessary to set the PUCCH for the additional secondary serving cell. Corresponding.
  • a propagation delay occurs while a radio wave propagates at a transmitter and is transmitted from a receiver. Therefore, even if both transmitters and receivers know exactly the time when radio waves propagate in the transmitter, the time that a signal arrives at the receiver is affected by the transmission / reception period distance, the surrounding radio wave environment, and changes with time when the receiver moves. If the receiver does not know exactly when the signal transmitted by the transmitter is received, even if the signal reception fails or is received, the receiver receives the distorted signal and communication is impossible.
  • synchronization between a base station and a terminal must be made in advance in order to receive an information signal regardless of downlink and uplink.
  • synchronization there are various types of synchronization, such as frame synchronization, information symbol synchronization, and sampling period synchronization.
  • Sampling period synchronization is the most basic synchronization to be obtained in order to distinguish physical signals.
  • Downlink synchronization acquisition is performed in the terminal based on the signal of the base station.
  • the base station transmits a specific signal mutually promised to facilitate downlink synchronization acquisition in the terminal.
  • the terminal should be able to accurately discern the time when the specific signal transmitted from the base station is transmitted.
  • the specific signals promised to each other include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell reference signal (CRS).
  • the base station receives signals transmitted from a plurality of terminals.
  • the signals received by each base station has a different transmission delay time, and when the uplink information is transmitted based on the downlink synchronization obtained respectively, the information of each terminal is different time Is received at the base station.
  • the base station cannot obtain synchronization based on any one terminal. Therefore, uplink sync acquisition requires a different procedure from downlink.
  • a random access procedure is performed for uplink synchronization acquisition.
  • the UE acquires uplink synchronization based on a timing advance value transmitted from the base station.
  • a timing advance value In terms of having an uplink time advance value, it is called a time advance value, and the time advance value may be called a timing alignment value.
  • the random access preamble is used to obtain a time advance value for synchronization of uplink time of the secondary serving cell.
  • a subframe in which the random access response message is received or uplink synchronization is received.
  • MAC CE MAC control elements
  • the UE starts a timing advance timer (TAT).
  • TAT timing advance timer
  • the terminal may start the time advance timer from the n + 6th subframe if the subframe receiving the random access response message or the subframe receiving the time advance value through the MAC CE is the nth subframe. If the time advance timer is in operation, the terminal determines that uplink synchronization is established between the terminal and the base station.
  • the time advance timer may be called a timing alignment timer.
  • one terminal communicates with a base station through a plurality of component carriers or a plurality of serving cells. If the signals transmitted from the terminal to the base station through the plurality of serving cells all have the same time delay, the terminal can obtain uplink synchronization for all the serving cells with one time forward value. On the other hand, if signals transmitted to a base station through a plurality of serving cells have different time delays, different time advance values are required for each serving cell. That is, multiple timing advance values are required. If the UE performs a random access procedure for each serving cell in order to acquire multi-time forward values, overhead is generated for limited uplink and downlink resources because the number of random access procedures required for uplink synchronization is increased. In addition, the complexity of the synchronization tracking procedure for maintaining uplink synchronization may increase. To reduce this overhead and complexity, a timing advance group (TAG) is defined. The temporal advance group may be called a timing alignment group.
  • TAG timing advance group
  • the TAG is a group including serving cell (s) using the same time forward value and the same timing reference or the timing reference cell including the timing reference among the serving cells configured with the UL CC.
  • the timing reference is a DL CC which is a reference for calculating the time forward value.
  • the same time forward value TA1 is applied to the first serving cell and the second serving cell, and the first serving cell.
  • the TA1 value is applied based on the downlink synchronization time of the DL CC of the second serving cell.
  • the TAG may include a main serving cell, may include at least one secondary serving cell, and may include a primary serving cell and at least one secondary serving cell.
  • Each TAG includes at least one serving cell configured with a UL CC, and information on the serving cell mapped to each TAG is called TAG configuration information.
  • the TAG is transmitted to the UE through RRC signaling when the initial group configuration and group reconfiguration are determined by the serving base station configuring the serving cell.
  • the main serving cell does not change the TAG.
  • the terminal should be able to support at least two TAG when a multi-time forward value is required.
  • TAGs divided into pTAGs (primary TAGs) including the primary serving cell and sTAGs (secondary TAGs) not including the primary serving cell.
  • pTAGs primary TAGs
  • sTAGs secondary TAGs
  • only one pTAG may exist at any time, and at least one sTAG may exist if a multi-time forward value is required. That is, if multiple time advance values are required, a plurality of TAGs may be set.
  • the maximum number of TAGs may be set to four.
  • the pTAG may be set to always have a predetermined value or no value.
  • TAG ID 0 may indicate pTAG.
  • the serving base station and the terminal may perform the following operations to obtain and maintain a time advance (TA) value for each TAG.
  • TA time advance
  • the serving base station and the terminal perform time acquisition and maintenance of pTAG through the main serving cell.
  • a timing reference as a reference for calculating and applying a TA value of a pTAG is always a DL CC in a main serving cell.
  • a non-competition based RA procedure initialized by the base station is used to obtain an initial uplink time forward value for sTAG.
  • the timing reference for the sTAG may be used by one of the activated secondary serving cells and set by the terminal.
  • the timing reference may be changed by the terminal to one serving cell among activated secondary serving cells except the timing reference. However, it is assumed that no unnecessary timing reference changes.
  • Each TAG has one timing reference and one timing advance timer (TAT).
  • TAT may be configured with a different timer expiration value. The TAT starts or restarts immediately after obtaining the time advance value from the serving base station to indicate whether the time advance value obtained and applied by each TAG is valid.
  • the TAT for all sTAGs should not be in progress unless the TTAG of the pTAG is running. That is, when the TAT of the pTAG has expired, the TAT of all TAGs including the pTAG expires and when the TAT for the pTAG is not in progress, the TAT for all sTAGs cannot be started.
  • the UE flushes the HARQ buffers of all serving cells. It also clears the resource allocation configuration for all downlink and uplink. For example, if the periodic resource allocation is configured without control information transmitted for resource allocation for downlink / uplink such as PDCCH, such as semi-persistent scheduling (SPS), the SPS configuration is initialized. do. In addition, the configuration of the PUCCH and type 0 (periodic) SRS of all serving cells is released.
  • PDCCH such as semi-persistent scheduling
  • Type 0 (cyclic) SRS configuration.
  • Type 1 (aperiodic) SRS configuration is maintained.
  • the terminal proceeds without stopping the TAT of the corresponding sTAG. This ensures the validity of the TA value of the sTAG through the TAT even when all secondary serving cells in the sTAG are inactive and no SRS and uplink transmission for tracking uplink synchronization is maintained for a certain time. It means.
  • the random access procedure for the secondary serving cell may be performed by the base station transmitting a PDCCH order indicating the start of the random access procedure through the PDCCH, which is a physical layer control information channel, for the activated secondary serving cell.
  • the PDCCH indication may include random access preamble index information that can be used in a secondary serving cell in an sTAG of a corresponding UE and PRACH mask index information that allows random access preamble transmission to all or part of time / frequency resources available in the secondary serving cell. It includes. Therefore, the random access procedure for the secondary serving cell is performed only through the non-competition based random access procedure.
  • the random access preamble information included in the PDCCH indication should be indicated as information other than '000000' to indicate the non-competition based random access procedure.
  • the PDCCH for transmitting a random access response may be transmitted through a serving cell other than the secondary serving cell that transmitted the random access preamble.
  • the PDCCH for RAR transmission may be transmitted through the main serving cell.
  • the path loss reference of the pTAG may be a primary serving cell or a secondary serving cell in the pTAG, and the base station may be configured differently through RRC signaling for each serving cell in the pTAG.
  • the path loss reference of uplink CCs of each serving cell in the sTAG is a downlink CC configured for SIB2, respectively.
  • the connection establishment to SIB2 means connection establishment between a DL CC configured based on information in SIB1 of a secondary serving cell and a UL CC configured based on information in SIB2.
  • SIB2 is one of the system information blocks transmitted through the broadcasting channel, and the SIB2 is transmitted from the base station to the terminal through the RRC reconfiguration procedure when configuring the secondary serving cell.
  • SIB1 information and SIB2 information transmitted to the UE through the RRC reconfiguration procedure may be different from SIB1 information and SIB2 information transmitted through the broadcasting channel of the secondary serving cell.
  • Uplink center frequency information is included in SIB2, and downlink center frequency information is included in SIB1.
  • FIG. 5 is a flowchart illustrating a procedure of obtaining a multi-time forward value according to an embodiment of the present invention.
  • the terminal and the base station perform an RRC connection establishment procedure through the selected cell (S500).
  • the selected cell becomes a main serving cell.
  • the RRC connection establishment procedure includes a process in which the base station transmits an RRC connection establishment message to the terminal, and the terminal transmits an RRC connection establishment complete message to the base station.
  • the base station performs an RRC connection reconfiguration procedure for additionally configuring at least one secondary serving cell to the terminal (S505).
  • the addition of the secondary serving cell may be performed when more radio resources need to be allocated to the terminal, for example, by the request of the terminal or the request of the network or the self-determination of the base station. Adding the secondary serving cell to the terminal or removing the secondary serving cell configured in the terminal may be indicated by an RRC connection reconfiguration message.
  • the RRC connection reconfiguration procedure includes a process in which a base station transmits an RRC connection reconfiguration message to a terminal, and a terminal transmits an RRC reconfiguration complete message to the base station.
  • the base station configures a TAG for the serving cell added to the terminal (S510).
  • the TAG configuration between serving cells may be cell-specific or eNB-specific.
  • a serving cell of a specific frequency band is always provided through an FSR or a remote radio head (RRH)
  • RRH remote radio head
  • Serving cells in the serviced frequency band may be set to belong to different TAGs, apart from the fact that they could be set to the same time forward value without the FSR or remote radio head.
  • the base station determines that the same time forward value as the main serving cell can be applied to the added secondary serving cell, the added secondary serving cell is set to the same TAG as the primary serving cell. In this case, the transmission operation of the TAG configuration information as in step S515 may not be performed. In this case, when the terminal receives the activation indicator and uplink scheduling information for the added secondary serving cell without receiving the TAG configuration information, the terminal considers the added secondary serving cell to be set to the same TAG as the main serving cell.
  • the base station configures an sTAG including the added secondary serving cell.
  • Each TAG is given a TAG ID for identifying the TAG.
  • the base station may selectively assign a TAG ID for the sTAG.
  • the base station grants a TAG ID for the sTAG before acquiring uplink synchronization through a random access procedure. can do.
  • the base station when the base station determines that the added secondary serving cell may be included in an existing TAG or cannot determine which TAG is included, the base station before acquiring uplink synchronization through a random access procedure The TAG ID for the sTAG may not be assigned. Therefore, in this case, the base station may transmit TAG configuration information to the terminal if necessary after the terminal acquires uplink synchronization, and the terminal may acquire the TAG ID of the corresponding sTAG.
  • the base station performs an RRC connection reconfiguration procedure for transmitting the TAG configuration information to the terminal (S515).
  • the TAG configuration information may be in a format including TAG ID information for each secondary serving cell.
  • the uplink configuration information of each secondary serving cell may include TAG ID information.
  • the TAG configuration information may be a format for mapping a serving cell index (ServCellIndex) allocated to each serving cell or a secondary serving cell index (ScellIndex) allocated only to secondary serving cells.
  • the secondary serving cells may mean a serving cell in the pTAG or may mean a serving cell in the sTAG independent from all TAGs currently configured.
  • the base station If the base station intends to schedule a specific secondary serving cell, the base station transmits an activation indicator for activating the specific secondary serving cell to the terminal (S520).
  • the terminal should acquire a time advance value to be adjusted for the specific sTAG. This may be implemented through a random access procedure indicated by the base station (S525).
  • the random access procedure for the activated secondary serving cell in the sTAG may be initiated by the PDCCH indication sent by the base station.
  • a secondary serving cell capable of receiving a PDCCH indication may be limited to a secondary serving cell including a timing reference specified in the sTAG, and may be any secondary serving cell configured in RACH or all secondary serving cells configured in RACH.
  • the base station controls so that the terminal does not simultaneously perform two or more random access procedures. Simultaneous progress of the random access procedure includes a case where two or more random access procedures are synchronized and progress simultaneously, and a case where the random access procedure is concurrently progressed for some time when the random access procedure proceeds. For example, when the UE proceeds with the random access procedure through the main serving cell, the random access procedure starts through the secondary serving cell while the UE waits for the random access response message (receives a PDCCH order).
  • the terminal may or may not include a section in which the random access response message is determined to be retransmitted.
  • the base station is enough information to map a specific secondary serving cell to a specific TAG even using the existing network information and / or assistant information (eg location information, RSRP, RSRQ, etc.) received from the terminal If not, the specific secondary serving cell is set to a new sTAG and the uplink time advance value is obtained through a random access procedure.
  • the existing network information and / or assistant information eg location information, RSRP, RSRQ, etc.
  • the terminal determines that the random access procedure is successfully completed, and updates the time forward value of the secondary serving cell (S530).
  • the random access response message may be included in a RAR MAC protocol data unit (PDU) received by being included in a PDSCH indicated by a PDCCH scrambled with a random access-radio network temporary identifier (RA-RNTI).
  • PDU RAR MAC protocol data unit
  • RA-RNTI random access-radio network temporary identifier
  • FIG. 5 an RRC connection reconfiguration procedure for configuring a secondary serving cell (S505) and a TAG configuration information transmission procedure (S515) for configuring a TAG are illustrated as being separately performed. However, this is only an example, and one RRC connection is performed.
  • the configuration information of the secondary serving cell and the TAG configuration information may be included in the reconfiguration message.
  • FIG. 6 illustrates a process in which secondary serving cell configuration information and TAG configuration information are transmitted by one RRC connection reconfiguration procedure.
  • FIG. 6 compares the secondary serving cell configuration information and the TAG configuration information to the terminal by one RRC connection reconfiguration procedure in step S610 when compared to FIG. 5.
  • the difference is that the TAG configuration is performed at one time. That is, TAG configuration information is also transmitted in the RRC connection reconfiguration procedure for transmission of secondary serving cell configuration information.
  • the configuration information of the secondary serving cell may include the TAG configuration information.
  • the configuration information of the secondary serving cell may include an index regarding the secondary serving cell added to the terminal, and an identifier (ID) of a TAG to which the secondary serving cell of the index belongs.
  • the TAG configuration information may include configuration information of the secondary serving cell.
  • the TAG configuration information may include a TAG ID of each TAG configured in the terminal, an index of a serving cell belonging to each TAG, an index of a secondary serving cell added to a specific TAG, and a TAT parameter.
  • the TAG configuration information may not be removed even if there is no serving cell belonging to the TAG. In other words, only the TAG ID and the TAT parameter may be included as configuration information for a specific TAG in the TAG configuration information.
  • the RRC connection reconfiguration message transmitted from the base station to the terminal in step S610 may be an initial RRC reconfiguration message received immediately after the successful RRC connection reconfiguration procedure, or may be another RRC reconfiguration message.
  • the remaining steps S600, S605, S615, S620, and S625 are the same as those in FIG. 5, and thus detailed descriptions thereof will be omitted.
  • the random access procedure of step S525 may be performed by, for example, the procedure of FIG. 7.
  • FIG. 7 is a flowchart illustrating a method of performing random access according to an embodiment of the present invention.
  • the base station transmits a PDCCH order for initiating a random access procedure for a secondary serving cell configured in the terminal to the terminal (S700).
  • the secondary serving cell may be determined that the base station needs uplink synchronization.
  • the base station selects one of pre-reserved dedicated random access preambles among all available random access preambles, and the index and the available time / frequency of the selected random access preamble.
  • Random access preamble assignment information including resource information is transmitted to the UE through a PDDCH indication. This is because the UE must be allocated a dedicated random access preamble with no possibility of collision for the non-contention based random access procedure from the base station.
  • the terminal may obtain a dedicated random access preamble from the handover command message.
  • the terminal may obtain a dedicated random access preamble through PDCCH, that is, physical layer signaling.
  • the physical layer signaling is downlink control information (DCI) format 1A and may include fields shown in Table 1 below.
  • the preamble index is an index indicating a preamble selected from among dedicated random access preambles reserved for the contention-free random access procedure
  • the PRACH mask index is available time / frequency resource information.
  • the available time / frequency resource information is indicated again according to a frequency division duplex (FDD) system and a time division duplex (TDD) system, as shown in Table 2 below.
  • FDD frequency division duplex
  • TDD time division duplex
  • the terminal transmits the random access preamble to the base station on the secondary serving cell designated in step S700 (S705).
  • the designated secondary serving cell may be the same as or different from the timing reference cell.
  • the random access preamble may be transmitted on another serving cell in the TAG to which the secondary serving cell belongs.
  • the base station transmits a random access response message to the terminal (S710).
  • the random access response message includes a time forward value.
  • the base station may determine which terminal transmits the random access preamble through which serving cell based on the received random access preamble and time / frequency resources.
  • the terminal initiates a random access procedure for the secondary serving cell by the PDCCH indication of the base station, the terminal has already obtained a unique identifier of the terminal, for example, a random access-RNTI (RA-RNTI) in the primary serving cell. It is a state. Therefore, the base station may transmit a random access response message to the terminal using the RA-RNTI of the terminal as needed.
  • RA-RNTI random access-RNTI
  • using the RA-RNTI includes scrambling the PDCCH indicating the PDSCH to which the random access response message is mapped to the RA-RNTI.
  • the terminal receives the random access response message from the base station, the terminal determines that the random access procedure has been completed successfully.
  • the UE may start or restart the TAT from a subframe receiving the random access response message or start or restart the TAT from an uplink subframe to which the TA value is applied.
  • the time advance value of the TAG is valid, and therefore, the time advance value and uplink synchronization of the serving cell configured in the TAG are also valid in principle.
  • the TAT of the sTAG expires, the TAT of another TAG does not expire.
  • the time forward value of the sTAG is no longer valid.
  • the secondary serving cell that belonged to sTAG1 may belong to sTAG2.
  • the terminal and the base station cannot determine that the secondary serving cell belongs to sTAG2 until the correct time advance value for the secondary serving cell is obtained.
  • the terminal and the base station need to quickly reconfigure the TAG even before obtaining the correct time forward value. Otherwise, the stability and reliability of the communication will be reduced.
  • the base station and the terminal may be forced to artificially reconfigure the TAG so that the TAG is the most reliable form.
  • the reliable form refers to a TAG in which the combination of secondary serving cells configured in the terminal can be formed with the highest probability in terms of network layout, statistics, or experience.
  • FIG. 8 is a flowchart illustrating an operation of a base station upon expiration of a TAT of an sTAG according to an embodiment of the present invention.
  • the base station confirms that the TAT of the sTAG has expired (S800).
  • the method for confirming that the TAT of the sTAG expires may include various embodiments.
  • the base station may check the expiration time of the TAT by driving a separate TAT at the time when the TAT of the terminal starts.
  • the base station checks whether the current sTAG configuration is the same as the sTAG initial configuration (S810).
  • the current sTAG configuration may mean a sTAG configuration configured in the terminal when the TAT of the sTAG expires.
  • the current sTAG configuration may mean a sTAG configuration configured in the terminal when the base station recognizes that the TAT of the sTAG has expired.
  • the current configuration of the sTAG is identical to the initial configuration of the sTAG, which means that the secondary serving cell constituting the current sTAG and the secondary serving cell based on the initial configuration of the sTAG are identical.
  • the configuration of the TAG may be classified into a TAG configuration based on cell-specific or eNB-specific criteria and a TAG configuration based on UE-specific criteria.
  • the base station configures the TAG based on information on the deployment environment of the network, and may be the same as S510 of FIG. 5. In this case, the base station can configure the TAG without the time advance value for each secondary serving cell.
  • the initial configuration of the TAG in S810 may include a TAG configuration based on cell specific criteria.
  • the base station may reconfigure the TAG based on the time advance value of the serving cell obtained based on a random access procedure, and the like. If the base station recognizes that the synchronization is not made or the uplink synchronization of the serving cell is not correct, the serving cell may be separated from the TAG configured with the serving cell to reconfigure the TAG.
  • the reconfiguration of the TAG may include a TAG configuration based on a UE-specific criterion and a TAG configuration based on a cell-specific or base station-specific criterion.
  • This can be called a reconstruction of the TAG.
  • the base station may transmit a PDCCH indication to the fourth serving cell in order to secure the time forward value of TAG3.
  • the base station In the case of the initial configuration of the TAG, the base station previously grasps information on the arrangement environment of the network for the initial configuration of the TAG for each terminal and uses the information. Therefore, even though the serving cells including the UL CC configured in the terminal may substantially all apply the same time advance value, the serving cell is determined to have potentially different time advance values based on the arrangement environment of the network. Are composed of different TAGs. That is, before the actual time advance value is secured, each secondary serving cell belongs to a predetermined TAG as a default.
  • the distance between the frequency bands is sufficiently separated.
  • the base station When configured in each inter-band (for example, 700MHz, 2GHz), the base station to apply the same time advance value to the serving cells based on the measured time advance value based on the random access procedure, etc. Even if it can be determined that the two serving cells are configured with different TAGs, the base station transmits information on the initial configuration of the TAG to the terminal through the RRC signaling.
  • the primary serving cell may provide a direct signal between the base station and the terminal. If only a path for transmitting and receiving exists, and the secondary serving cell has only a path for transmitting and receiving a signal through an RRH or a repeater, the base station transmits to the serving cells based on a time advance value measured through a random access procedure. Even if it is determined that the same time advance value can be applied, the two serving cells are configured with different TAGs, and the base station transmits information on the initial configuration of the TAG to the terminal through RRC signaling.
  • the primary serving cell is a direct signal between the base station and the terminal.
  • the time base station is measured through a random access procedure.
  • the base station receives a random access preamble on the secondary serving cell from the terminal based on the random access procedure indicated by the base station (PDCCH order), and provides a time advance value for uplink of the secondary serving cell.
  • the TAG can be reconstructed based on the time advance value obtained. Therefore, even if the same TAG is configured according to the information on the deployment environment of the network, the serving cells having different time advance values may be configured with different TAGs.
  • the serving cells are configured in the same frequency band, and the network includes both the primary serving cell and the secondary serving cell. It is determined that only a path for directly transmitting and receiving a signal between the base station and the terminal is configured to the same TAG (for example, pTAG).
  • the secondary serving cell may not only exist a path for transmitting and receiving a signal through a repeater but also a path for transmitting and receiving a signal directly between a base station and a terminal.
  • a repeater not known in advance in the network is called a hidden repeater.
  • the base station configures two serving cells of the same TAG with different TAGs based on the time advance value measured through a random access procedure. Thereafter, the base station transmits the TAG configuration information to the terminal through the RRC signaling.
  • the base station performs a random access procedure (RA procedure) through the PDCCH indication (S840).
  • the base station may first transmit an activation indicator when necessary for proceeding with the random access procedure.
  • step S810 the base station reconfigures the corresponding sTAG such that the sTAG is the initial configuration (S820).
  • the base station initializes the sTAG based on information on the network deployment environment.
  • the base station sTAG sTAG1 ⁇ first secondary serving cell ⁇
  • sTAG2 ⁇ second secondary serving cell
  • sTAG3 ⁇ fourth secondary serving cell ⁇ based on the information on the network deployment environment Reconstruct with
  • the base station When the sTAG is reconfigured to the initial configuration state, the base station performs an RRC connection reconfiguration procedure for transmitting the TAG configuration information to the terminal (S830).
  • the RRC connection reconfiguration procedure includes a base station transmitting an RRC connection reconfiguration message to a terminal and a terminal transmitting an RRC connection reconfiguration complete message to the base station.
  • the base station performs a random access procedure through the PDCCH indication (S840).
  • the base station may first transmit an activation indicator when necessary for proceeding with the random access procedure.
  • FIG. 9 is a flowchart illustrating an operation of a terminal when the TAT of an sTAG expires according to an embodiment of the present invention.
  • the terminal may perform the following operation without receiving the TAG configuration information through the RRC connection reconfiguration procedure from the base station.
  • the terminal confirms that the TAT of the sTAG has expired (S900).
  • the terminal checks whether the current sTAG configuration and the sTAG initial configuration are the same (S910).
  • the sTAG initial configuration includes the sTAG configuration based on cell specific or base station specific criteria as described above.
  • the sTAG initial configuration may be based on network deployment environment information.
  • the terminal If the current sTAG configuration is the same as the initial configuration of the sTAG, the terminal maintains the current configuration of the sTAG, and cancels or stops uplink transmission through the sTAG.
  • the terminal receives a PDCCH indication from the base station and proceeds with a random access procedure (S930).
  • the terminal may first receive an activation indicator when necessary for proceeding with the random access procedure.
  • step S910 if the current sTAG configuration and the sTAG initial configuration is not the same, the terminal initializes the sTAG (S920).
  • Initializing the sTAG means unconfiguring the sTAG or returning to the initial configuration state of the sTAG (for example, configuring the TAG based on information on the network deployment environment). In this case, uplink transmission for secondary serving cells belonging to the corresponding sTAG is canceled or stopped.
  • the operation of initializing the sTAG may be performed by the terminal itself. For example, when the terminal releases the configuration of the sTAG, the configuration of the corresponding sTAG may be released without receiving a command from the base station. Alternatively, the terminal may store the initial configuration of the sTAG configured from the base station or, if known, the terminal may return the sTAG to the initial configuration state without receiving the RRC reconfiguration command from the base station.
  • the terminal receives a PDCCH indication indicating the start of the random access procedure from the base station and proceeds with the random access procedure (S930).
  • the terminal may first receive an activation indicator when necessary for proceeding with the random access procedure.
  • a base station transmits a PDCCH indication indicating a start of a random access procedure for a secondary serving cell configured in the terminal to the terminal, and the terminal receives the PDCCH indication and based on the random access procedure. Transmitting the access preamble to the base station. Thereafter, the base station may include transmitting a random access response message to the terminal.
  • the random access procedure may be stopped. That is, for example, when the terminal receives a PDCCH indication indicating the start of a random access procedure for the secondary serving cell configured in the sTAG from the base station before the TAT of the sTAG expires in S900, the terminal receives the PDCCH indication.
  • the random access preamble may not be transmitted to the base station. This is because the random access procedure is for acquiring uplink synchronization of the sTAG. If the sTAG of the secondary serving cell performing the random access procedure is changed, the uplink synchronization cannot be obtained based on the random access procedure in progress. .
  • FIG. 10 is a flowchart illustrating an operation of a terminal when a TAT of sTAG expires during a random access procedure according to an embodiment of the present invention.
  • the terminal receives a PDCCH indication indicating the start of a random access procedure from a base station on a secondary serving cell 1 (SCell 1) configured in the terminal (S1000).
  • the secondary serving cell 1 is included in the sTAG.
  • the terminal confirms that the TAT expiration of the sTAG has expired (S1010).
  • the terminal checks whether the current sTAG configuration and the sTAG initial configuration are the same (S1020).
  • the terminal If the current sTAG configuration is the same as the initial configuration of the sTAG, the terminal maintains the current configuration of the sTAG, and cancels or stops uplink transmission through the sTAG.
  • the terminal transmits a random access preamble on the secondary serving cell 1 (S1030). Thereafter, the terminal may receive a random access response message regarding the random access preamble from the base station.
  • step S1010 when the current sTAG configuration is not the same as the initial sTAG configuration, the terminal initializes the current sTAG and stops the random access procedure performed on the secondary serving cell 1 (S1040).
  • Initializing the sTAG means unconfiguring the sTAG or reverting to the initial configuration state of the sTAG (that is, configuring the TAG based on information on the network deployment environment). In this case, uplink transmission for secondary serving cells belonging to the corresponding sTAG is canceled or stopped.
  • the sTAG may be configured through an RRC connection reconfiguration procedure before performing steps S1050 and S1060 for the corresponding sTAG.
  • the terminal receives a PDCCH indication from the base station indicating the start of the random access procedure on the secondary serving cell 2 constituting the initialized sTAG (S1050).
  • the secondary serving cell 2 may be the same as or different from the secondary serving cell 1.
  • sTAG1 ⁇ first secondary serving cell, fourth secondary serving cell ⁇ configured in the terminal, and after receiving a PDCCH indication indicating a random access procedure on the first secondary serving cell, the TAT for sTAG1 expires.
  • the UE may receive a PDCCH indication on the first secondary serving cell constituting the initialized sTAG1.
  • the secondary serving cell 2 is the same as the secondary serving cell 1.
  • the terminal may receive a PDCCH indication on the first secondary serving cell constituting the initialized sTAG1.
  • the secondary serving cell 2 is different from the secondary serving cell 1.
  • the terminal transmits a random access preamble to the base station on the secondary serving cell 2 (S1060). Thereafter, the terminal may receive a random access response message regarding the random access preamble from the base station, and may perform uplink transmission through the sTAG in which the secondary serving cell 2 is configured.
  • FIG. 10 illustrates the operation of the terminal when the TAT of the sTAG is expired during the random access procedure. This includes all operations for the case where the current sTAG configuration and the sTAG initial configuration are different from the same case.
  • an operation flowchart between the terminal and the base station when the current sTAG configuration and the sTAG initial configuration are different will be described below.
  • FIG. 11 is a flowchart illustrating operations of a terminal and a base station when a TAT of sTAG expires during a random access procedure according to an embodiment of the present invention.
  • the base station performs an RRC connection reconfiguration procedure for transmitting TAG configuration information to the terminal (S1100).
  • the RRC connection reconfiguration procedure may include the step of the base station transmitting an RRC connection reconfiguration message including the TAG configuration information to the terminal, and the terminal transmitting the RRC reconfiguration complete message to the base station.
  • the base station and the terminal perform a random access procedure indicated by the base station (S1110).
  • the UE may obtain a time advance value to be adjusted for the sTAG through the random access procedure.
  • the base station may first transmit an activation indicator when necessary for proceeding with the random access procedure.
  • the UE may perform uplink transmission in the sTAG based on uplink synchronization secured through the random access procedure (S1120). For example, the terminal may transmit a Sounding Reference Signal (SRS), a PUSCH, and a Demodulation Reference Signal (DM-RS) to the base station in synchronization with uplink.
  • SRS Sounding Reference Signal
  • PUSCH PUSCH
  • DM-RS Demodulation Reference Signal
  • the base station transmits a PDCCH indication to the terminal on the secondary serving cell 1 configured in the sTAG (S1130).
  • the base station may obtain a time advance value of sTAG.
  • the terminal may start or restart the TAT from a subframe receiving the random access response message from the base station, or may start or restart the TAT from an uplink subframe when the time advance value is applied.
  • the terminal transmits the random access preamble to the base station the TAT of the sTAG expires, and the terminal confirms the expiration of the TAT of the sTAG (1140).
  • the terminal initializes the sTAG (S1150).
  • Initializing the sTAG means releasing the configuration of the current sTAG or returning the configuration of the current sTAG to the initial configuration state of the sTAG (that is, the configuration of the TAG based on information on the network deployment environment).
  • the terminal stops the random access procedure that was in progress on the secondary serving cell 1 (S1160).
  • the suspension of the random access procedure includes the UE not transmitting the random access preamble related to S1130 on the secondary serving cell 1 or ignoring or discarding the random access response message transmitted from the base station.
  • the base station transmits a PDCCH indication on the secondary serving cell 2 configured in the initialized sTAG (S1170).
  • the terminal may transmit a random access preamble to the base station on the secondary serving cell 2, and the terminal may receive a random access response message regarding the random access preamble from the base station, and the secondary serving cell 2 is upward through the configured sTAG.
  • Link transmission may also be performed.
  • the present invention is not only the case that the TAT of the sTAG expires during the random access procedure to change the configuration secondary serving cell of the sTAG, the secondary serving cell in which the random access procedure is in progress by reconfiguration of the TAG performed by the base station belongs to It can be applied when the sTAG is changed.
  • the terminal may operate as follows.
  • FIG. 12 is a flowchart illustrating an operation of a terminal when the sTAG to which the secondary serving cell 1 belongs during the random access procedure is changed according to an embodiment of the present invention.
  • the terminal receives an RRC connection reconfiguration message including TAG configuration information from the base station (S1200).
  • the UE checks whether a random access procedure is in progress on the secondary serving cell 1 (SCell1) (S1210).
  • SCell1 secondary serving cell 1
  • the random access procedure on the secondary serving cell 1 is in progress.
  • the terminal receives a PDCCH indication indicating the start of the random access procedure for the secondary serving cell 1 from the base station, the terminal receives a random access response message from the base station. It refers to a state before receiving and completing a random access procedure.
  • the terminal After the UE receives a PDCCH indication indicating the start of the random access procedure for the secondary serving cell 1 from the base station, the terminal has not yet transmitted the random access preamble on the secondary serving cell 1 to the base station, or Even if the random access frame is transmitted to the base station, if the random access response message is not received from the base station, the random access procedure may be in progress.
  • the terminal completes the reconfiguration of the TAG or the secondary serving cell based on the TAG configuration information and transmits an RRC reconfiguration complete message to the base station (S1250).
  • step S1210 if the random access procedure is in progress on the secondary serving cell 1, the UE checks whether the sTAG including the secondary serving cell 1 is changed (S1220).
  • the change of the sTAG including the secondary serving cell 1 means that the secondary serving cell is excluded from the existing sTAG by the TAG configuration information and is included in another sTAG or pTAG.
  • S1210 is shown as being performed before S1220 in FIG. 12, S1220 may be performed before S1210 and S1210 and S1220 may be performed simultaneously. If S1220 is performed before S1210, S1230 assumes an operation when a random access procedure is in progress in secondary serving cell1.
  • the terminal continues without stopping the random access procedure in progress on the secondary serving cell 1 (S1230). For example, if the terminal has not yet transmitted the random access preamble to the base station on the secondary serving cell 1 transmits the random access preamble. Alternatively, when the terminal transmits the random access preamble to the base station on the secondary serving cell 1 but has not yet received the random access response message, the terminal may receive the random access response message and obtain a time advance value based thereon.
  • the terminal may then adjust uplink synchronization of the secondary serving cell 1 based on the time advance value and perform uplink transmission on the secondary serving cells of the sTAG including the secondary serving cell 1.
  • the terminal transmits an RRC reconfiguration complete message to the base station (S1250).
  • FIG. 12 illustrates that S1230 is performed before S1250, S1250 may be performed before S1230, and S1230 and S1250 may be simultaneously performed.
  • step S1220 if the sTAG including the secondary serving cell 1 is changed, the terminal stops the random access procedure that was in progress on the secondary serving cell 1 (S1240). For example, if the terminal has not yet transmitted the random access preamble to the base station on the secondary serving cell 1, the terminal stops transmitting the random access preamble. Or, even if the terminal receives the random access response message, it ignores or discards it.
  • the sTAG of the second secondary serving cell is changed from sTAG1 to sTAG2.
  • the second secondary serving cell may resume uplink transmission using the time advance value used in sTAG2.
  • the random access procedure that was performed on the second secondary serving cell is suspended.
  • the UE subsequently serves a serving cell in the new TAG to which the base station and the secondary serving cell 1 belong (the primary serving when the newly configured TAG is pTAG).
  • a random access procedure may be performed on a cell, a secondary serving cell in case of an sTAG, to acquire a time advance value of a new TAG, and perform uplink transmission.
  • the terminal transmits an RRC reconfiguration complete message to the base station (S1250).
  • FIG. 12 illustrates that S1240 is performed before S1250, S1250 may be performed before S1240, and S1240 and S1250 may be performed simultaneously.
  • FIG. 12 illustrates the operation of a terminal according to whether a random access procedure is performed when an RRC connection reconfiguration procedure is performed.
  • an sTAG including a secondary serving cell is changed, an operation flowchart between the terminal and the base station is as follows. .
  • FIG. 13 is a flowchart illustrating operations of a terminal and a base station when an sTAG including the secondary serving cell is changed during a random access procedure on the secondary serving cell according to an embodiment of the present invention.
  • the base station performs an RRC connection reconfiguration procedure for transmitting TAG configuration information to the terminal (S1300).
  • the RRC connection reconfiguration procedure may include the step of the base station transmitting an RRC connection reconfiguration message including the TAG configuration information to the terminal, and the terminal transmitting the RRC reconfiguration complete message to the base station.
  • the base station and the terminal perform a random access procedure indicated by the base station (S1310).
  • the UE may obtain a time advance value to be adjusted for the sTAG through the random access procedure.
  • the base station may first transmit an activation indicator when necessary for proceeding with the random access procedure.
  • the UE may perform uplink transmission in the sTAG based on uplink synchronization secured through the random access procedure (S1320). For example, the terminal may transmit a Sounding Reference Signal (SRS), a PUSCH, and a Demodulation Reference Signal (DM-RS) to the base station in synchronization with uplink.
  • SRS Sounding Reference Signal
  • PUSCH PUSCH
  • DM-RS Demodulation Reference Signal
  • the base station transmits a PDCCH indication to the terminal on the secondary serving cell 1 configured in the sTAG (S1330).
  • the PDCCH indication indicates to the UE to start a random access procedure for the secondary serving cell1.
  • the base station transmits an RRC connection reconfiguration message including the TAG configuration information to the terminal (S1340).
  • the terminal Stops the random access procedure in progress on the secondary serving cell 1 (S1350).
  • the terminal may stop the random access procedure without transmitting the random access preamble related to the S1330 on the secondary serving cell1.
  • the terminal may ignore or discard the random access response message transmitted from the base station.
  • the terminal transmits an RRC reconfiguration complete message to the base station (S1360).
  • S1350 may be performed before S1360, or may be performed simultaneously.
  • the base station may assume that the random access procedure previously performed on the secondary serving cell 1 is stopped and perform the following operation.
  • the base station subsequently attaches to the secondary of the sTAG1.
  • the random access procedure may be performed by transmitting a PDCCH indication to the UE on the serving cell.
  • the terminal may perform uplink transmission in the secondary serving cell 1 using the time advance value used in sTAG2.
  • the base station transmits an activation indicator first if necessary to activate or reactivate the secondary serving cell, and then transmits a PDCCH indication on the secondary serving cell of sTAG2.
  • the random access procedure may also be performed by transmitting to.
  • the secondary serving cell reactivation means restarting a deactivation timer configured for each secondary serving cell.
  • the terminal may receive an activation indicator from the base station. It may omit and activate or reactivate the secondary serving cell.
  • FIG. 14 is a flowchart illustrating an operation of a terminal when a secondary serving cell according to an embodiment of the present invention is reconfigured to sTAG for which uplink synchronization is not secured.
  • the terminal receives an RRC connection reconfiguration message including TAG configuration information from the base station (S1400).
  • the terminal reconfigures the TAG of the terminal based on the TAG configuration information.
  • the base station determines from the TAG so that the secondary serving cell is included in another TAG.
  • the TAG may be reconfigured by removing the secondary serving cell, and the reconfigured TAG configuration information may be transmitted to the terminal through an RRC connection reconfiguration message.
  • the terminal checks whether the TAG including the secondary serving cell is changed (S1410).
  • TAG2 is a TAG for which uplink synchronization is not secured.
  • the UE transmits an RRC reconfiguration complete message to the base station (S1440).
  • the terminal checks whether uplink synchronization of the TAG after the change is secured (S1420).
  • the terminal transmits an RRC reconfiguration complete message to the base station (S1430).
  • the changed TAG refers to TAG2 based on the second secondary serving cell when viewed in the example described in S1410.
  • step S1420 if uplink synchronization of the TAG after the change is not secured, the terminal activates at least one secondary serving cell included in the TAG after the change (S1430). This means that the terminal voluntarily activates the secondary serving cell without an activation instruction by the base station. When a plurality of secondary serving cells are configured in the TAG after the change, the terminal may activate all secondary serving cells configured in the TAG after the change.
  • the terminal changes the secondary serving cell to an active state, and if the secondary serving cell is activated, the terminal reactivates the secondary serving cell.
  • the reactivation operation refers to an operation of restarting a deactivation timer set in the secondary serving cell.
  • the base station intentionally performing TAG reconfiguration to change the TAG of the secondary serving cell may be interpreted as being intended to secure uplink synchronization of the secondary serving cell. This is because, if the base station does not intend to secure uplink synchronization, the problem may be solved by releasing an uplink CC of the corresponding secondary serving cell or deactivating the secondary serving cell. Therefore, in this case, the base station does not need to send an additional activation indicator to the terminal. Accordingly, the terminal may immediately activate or reactivate the corresponding secondary serving cell without receiving an additional activation indicator from the base station.
  • the base station may not be able to clearly determine whether the secondary serving cell is inactivated. For example, the base station transmits PDCCH information for uplink or downlink resource allocation for the secondary serving cell to activate the secondary serving cell. However, the UE may not properly receive the PDCCH and may inform the BS through HARQ NACK information. However, the base station may receive the HARQ NACK information by mistaken for the ACK information. In this case, since the terminal cannot restart the deactivation timer, the secondary serving cell may be deactivated, but the base station may determine that the secondary serving cell is in an activated state. In this case, when the TAG of the secondary serving cell is changed to a TAG (eg, a newly added TAG) for which uplink synchronization is not secured, this problem may be solved by activating the secondary serving cell.
  • a TAG eg, a newly added TAG
  • the time point at which the secondary serving cell is activated or reactivated may be from the subframe at the position of n + 8 when the subframe starting the activation operation is n.
  • the UE may start an activation operation of the secondary serving cell based on a subframe including a time point at which the UE receives the RRC connection reconfiguration message.
  • an activation operation of the secondary serving cell may be started based on a time when the UE transmits a subframe in which the RRC connection reconfiguration message is received or an RRC reconfiguration complete message.
  • the terminal After activation of the secondary serving cell, the terminal transmits an RRC reconfiguration complete message to the base station (S1440).
  • the terminal may perform a random access procedure with the base station on the secondary serving cell included in the TAG after the change, and may also perform uplink transmission.
  • FIG. 14 an operation of activating the secondary serving cell when the TAG including the secondary serving cell is changed and the secondary serving cell is included as an sTAG for which synchronization is not secured has been described with reference to the terminal.
  • the TAG that is not secured may be, for example, a newly added TAG, and a series of operations of the terminal and the base station when the secondary serving cell is reconfigured with the newly added TAG may be, for example, as follows.
  • FIG. 15 is a flowchart illustrating operations of a terminal and a base station when a secondary serving cell is reconfigured with a newly added TAG according to an embodiment of the present invention.
  • FIG. 15 illustrates a case where a TAG is changed by a TAG reconfiguration and a secondary serving cell is included in a newly added TAG, and this description is also applicable to a case of a TAG for which uplink synchronization is not secured.
  • the base station reconfigures the TAG (S1500).
  • the TAG reconfiguration may include a TAG configuration based on cell-specific or eNB-specific criteria and a TAG configuration based on UE-specific criteria.
  • the base station may reconfigure the TAG based on information about a deployment environment of the network.
  • the base station may reconfigure the TAG based on the time advance value of the secondary serving cell obtained based on a random access procedure or the like and receive uplink data through the secondary serving cell.
  • the base station may reconfigure the TAG by removing the secondary serving cell from the TAG so that the secondary serving cell is included in another TAG. have.
  • the base station transmits an RRC connection reconfiguration message including the TAG configuration information to the terminal (S1510).
  • the terminal may reconfigure the TAG based on the TAG configuration information.
  • the terminal When the terminal reconfigures the TAG based on the TAG configuration information, when the TAG including the secondary serving cell is changed to a newly added TAG, that is, when the secondary serving cell belongs to the newly added TAG, the secondary serving cell Activate (S1520).
  • the newly added TAG means that the TAG of the index, which was not present before the reception of the TAG configuration information, is newly added by the TAG configuration information on a terminal basis.
  • TAG1 ⁇ first secondary serving cell
  • second secondary serving cell ⁇ is configured in the terminal, and an RRC connection reconfiguration procedure is performed
  • TAG1 ⁇ first secondary serving cell ⁇
  • TAG2 ⁇ second secondary serving cell ⁇
  • the TAG2 corresponds to the newly added TAG when viewed based on the terminal, and the second secondary serving cell may be regarded as configured in the newly added TAG.
  • the terminal transmits an RRC reconfiguration complete message to the base station (S1530).
  • S1520 is illustrated as being performed before S1530 in FIG. 15, S1530 may be performed before S1520 or may be performed simultaneously.
  • a time advance value to be adjusted for the secondary serving cell should be obtained. This may be implemented through a random access procedure indicated by the base station. That is, the terminal and the base station can then perform a random access procedure for the secondary serving cell configured in a new TAG (S1540). Since the terminal has already activated or reactivated the secondary serving cell in S1520, the base station may initiate a random access procedure without transmitting a separate activation indicator.
  • the random access procedure for example, the base station transmitting a PDCCH indication indicating the start of the random access procedure for the secondary serving cell to the terminal, the terminal transmits a random access preamble on the secondary serving cell to the base station
  • the method may include transmitting, by the base station, a random access response message to the terminal on the primary serving cell.
  • the terminal may update the time advance value of the new TAG based on the time advance value included in the random access response message (S1550).
  • the sTAG may be initialized to quickly reconfigure the TAG, and unnecessary random access is performed when the TAG configured as the secondary serving cell is changed during the random access procedure on the secondary serving cell.
  • the random access procedure can be started immediately after the change in the TAG (specifically, one of the secondary serving cells configured in the TAG after the change) without waiting for the procedure to be completed.
  • the secondary serving cell is reconfigured to a TAG (for example, a newly added TAG) with no uplink synchronization, the secondary serving cell is activated or reactivated at the terminal without waiting for an activation indicator from the base station and immediately on the secondary serving cell.
  • a random access procedure can be performed.
  • the operation of the terminal and the base station may vary, and in this case, the terminal and the base station may be implemented as follows.
  • FIG. 16 illustrates an operation of a terminal when a TAG is changed according to an embodiment of the present invention.
  • the terminal receives an RRC connection reconfiguration message including the TAG configuration information for reconfiguration of the TAG from the base station or initializes the TAG based on another cause (S1600).
  • the cause of the initialization of the TAG may include the TAT expiration of the TAG. That is, when the TAT of the TAG expires, initialization of the TAG may be triggered.
  • TAG includes a secondary serving cell 1 (SCell1).
  • the terminal checks whether the TAG including the secondary serving cell 1 is changed (S1610).
  • the terminal continues the ongoing operation. For example, if the secondary serving cell 1 was in the process of random access procedure, the random access procedure continues. If uplink transmission is performed through secondary serving cell 1, the transmission continues.
  • the terminal checks whether the random access procedure is in progress in the secondary serving cell 1 (S1620).
  • the random access procedure on the secondary serving cell 1 is in progress.
  • the terminal receives a PDCCH indication indicating the start of the random access procedure for the secondary serving cell 1 from the base station, the terminal receives a random access response message from the base station. It refers to a state before receiving and completing a random access procedure.
  • the terminal stops the random access procedure in progress on the secondary serving cell 1 (S1630).
  • the UE may resume uplink transmission on the secondary serving cell 1 using the time advance value used in the changed TAG. If the TAT of the TAG is not in progress after the change, the UE performs a random access procedure on the BS and the secondary serving cell configured in the TAG after the change to obtain a time advance value of the TAG after the change, and based on the change, the TAG after the change Uplink transmission can be initiated on the secondary serving cell configured in FIG.
  • step S1620 if the random access procedure is not in progress in the secondary serving cell 1, the UE checks whether the changed TAG to which the secondary serving cell 1 belongs is a newly added TAG (or a TAG that does not have uplink synchronization). (S1640).
  • the terminal continues the ongoing operation. For example, if the changed TAG is not a newly added TAG and the TAT is in progress (or if the TAG is not an sTAG for which uplink synchronization is not secured after the change, the TAG is in progress after the change), the terminal Uplink transmission can be resumed on the secondary serving cell 1 using the time advance value used in the TAG after the change.
  • the UE may include at least one secondary serving cell included in the newly added TAG (the TAG after the change is not secured with uplink synchronization).
  • the UE performs a random access procedure on the secondary serving cell included in the newly added TAG, acquires a time advance value of the newly added TAG, and based on the secondary serving cell included in the newly added sTAG. Uplink transmission may be initiated.
  • FIG. 17 illustrates an operation of a base station when a TAG is changed according to an embodiment of the present invention.
  • the base station transmits an RRC connection reconfiguration message including the TAG configuration information for reconfiguration of the TAG to the terminal (S1700). Thereafter, when the terminal reconfigures the TAG of the terminal based on the TAG configuration information, the terminal may transmit an RRC reconfiguration complete message to the base station.
  • the transmission of the RRC reconfiguration complete message may be performed during subsequent steps or may be performed after all steps are completed.
  • the base station checks whether the TAG including the secondary serving cell 1 is changed (S1710).
  • the base station continues the ongoing operation. For example, if the secondary serving cell 1 was in the process of random access procedure, it continues without stopping the random access procedure. If uplink reception is performed through the secondary serving cell 1, the uplink reception continues.
  • the base station determines whether a random access procedure is in progress in the secondary serving cell 1 (S1720).
  • the base station transmits a PDCCH indication to the terminal on the secondary serving cell 2 configured in the TAG after the change without waiting for the random access procedure to be terminated (S1730).
  • the base station may immediately transmit a PDCCH indication indicating the start of the random access procedure to the terminal, without having to wait for the random access procedure to terminate.
  • the base station transmits the RRC connection reconfiguration message or receives the RRC connection reconfiguration complete message in S1700, the base station may assume that the random access procedure previously performed on the secondary serving cell 1 is stopped and perform the above operation.
  • step S1720 if the random access procedure is not in progress in the secondary serving cell 1, the base station determines whether the changed TAG is a newly added TAG (or a TAG for which uplink synchronization is not secured) (S1740).
  • the base station continues the ongoing operation. For example, if the changed TAG is not a newly added TAG and the TAT is in progress (or if the TAG is not a TAG for which uplink synchronization is not secured after the change, the TAG is in progress after the change), the terminal Uplink transmission can be resumed on the secondary serving cell 1 using the time advance value used in the TAG after the change.
  • the base station transmits a PDCCH indication indicating the start of a random access procedure on the secondary serving cell 2 included in the newly added TAG ( S1730).
  • the base station since the UE activates the secondary serving cell (and the TAG configured secondary serving cell after the change) included in the newly added TAG in S1650, the base station directly instructs the start of the random access procedure without transmitting an activation indicator separately. Instructions may be sent to the terminal.
  • the base station when the base station transmits an RRC connection reconfiguration message or receives an RRC reconfiguration complete message, the base station reports that the secondary serving cell included in the newly added TAG is activated or reactivated, and immediately transmits a PDCCH indication to the UE and randomly accesses the UE. You can proceed with the procedure.
  • the BS and the UE may acquire a time advance value of the TAG after the change based on the random access procedure, and may start or resume uplink transmission on the secondary serving cell configured in the TAG after the change.
  • FIG. 18 is a block diagram illustrating a terminal and a base station according to an embodiment of the present invention.
  • the terminal 1800 includes a receiver 1805, a terminal processor 1810, and a transmitter 1820.
  • the terminal processor 1810 includes an RRC processor 1811 and a MAC processor 1812.
  • the receiver 1805 receives secondary serving cell configuration information, TAG configuration information, PDCCH order, random access response message, and activation indicator from the base station 1850.
  • the RRC processing unit 1811 generates a message used in the RRC procedure or receives it from the base station 1850.
  • the RRC procedure includes, for example, an RRC connection establishment procedure and an RRC connection reconfiguration procedure.
  • the RRC connection reconfiguration message used in the RRC connection reconfiguration procedure may include at least one of secondary serving cell configuration information and TAG configuration information.
  • the RRC processing unit 1811 configures the main serving cell and at least one secondary serving cell used for carrier aggregation in the terminal 1800 with carrier aggregation.
  • the procedure of additionally configuring the secondary serving cell in the terminal 1800 or removing the secondary serving cell that is already configured may be indicated by the secondary serving cell configuration information.
  • the RRC processor 1811 reconfigures the TAG based on at least one of the secondary serving cell configuration information and the TAG ID indicated by the TAG configuration information.
  • the RRC processor 1811 reconfigures the TAG such that the secondary serving cell is included in the TAG.
  • the RRC processing unit 1811 adds or removes the secondary serving cell according to the instruction of the information field. Update or reconfigure the TAG in which the serving cell is added or removed.
  • the RRC processing unit 1811 may initialize the corresponding sTAG. Specifically, the RRC processing unit 1811 cancels the configuration of the sTAG or returns to the initial configuration state of the sTAG.
  • the method of returning the sTAG to the initial configuration state may include the method of step S920 of FIG. 9 or step S1150 of FIG. 11.
  • the RRC processor 1811 may reconfigure the TAG based on the time advance value for the secondary serving cell transmitted from the MAC processor 1812.
  • TAG reconfiguration when a TAG having a time advance value equal to a time advance value applied to a previously configured TAG (pTAG or sTAG) exists, the RRC processor 1811 maps the added secondary serving cell to the corresponding TAG. .
  • the RRC processor 1811 activates or reactivates the secondary serving cell constituting the newly added sTAG when there is a newly added sTAG.
  • the RRC processor 1811 may voluntarily activate or reactivate the secondary serving cell without an activation instruction by the base station.
  • the MAC processor 1812 generates a random access preamble according to the PDCCH indication, and sends the random access preamble to the transmitter 1820.
  • the MAC processing unit 1812 obtains the time advance value for the secondary serving cell from the random access response (RAR) message received from the receiver 1805, and controls the uplink synchronization for the secondary serving cell as the time advance value. do.
  • the MAC processor 1812 may provide the time advance value to the RRC processor 1811 to allow the RRC processor 1811 to perform TAG reconfiguration.
  • the MAC processor 1812 determines the MAC. Abort the random access procedure that was in progress on the secondary serving cell. For example, before the MAC processor 1812 still transmits the random access preamble to the base station 1850 through the transmitter 1820, the MAC processor 1812 stops generating or transmitting the random access preamble. Alternatively, when the MAC processor 1812 transmits the random access preamble to the base station 1850 through the transmitter 1820, but has not yet received the random access response message through the receiver 1805, a random access response message received thereafter. Ignore or discard.
  • the RRC processing unit 1811 may add the newly added TAG (or upward).
  • the secondary serving cell constituting the TAG with no link synchronization may be activated or reactivated. This is that the RRC processing unit 1811 of the terminal 1800 voluntarily activates or reactivates the secondary serving cell without an activation instruction by the MAC processing unit 1872 of the base station 1850.
  • the transmitter 1820 transmits a random access preamble, an RRC reconfiguration complete message, or an activation indicator to the base station 1850.
  • the base station 1850 includes a transmitter 1855, a receiver 1860, and a base station processor 1870.
  • the base station processor 1870 includes an RRC processor 1187 and a MAC processor 1872.
  • the transmitter 1855 transmits secondary serving cell configuration information, TAG configuration information, PDCCH indication, RAR, and activation indicator to the terminal 1800.
  • the transmission unit 1855 may include the TAG configuration information in the secondary serving cell configuration information and transmit the secondary serving cell configuration information and the TAG configuration information independently.
  • the receiver 1860 receives a random access preamble and an RRC reconfiguration complete message from the terminal 1800.
  • the RRC processor 1187 determines the addition or removal of the secondary serving cell for the terminal 1800. As an example, when the frequency band required by the terminal 1800 is reduced or when the connection with the secondary serving cell of the serving base station is released due to handover, the RRC processor 1187 may determine the secondary serving cell configured in the terminal 1800. Removal can be determined. As another example, when the bandwidth to support the terminal 1800 increases or when accessing a new cell of the target base station by handover, the RRC processor 1187 may determine the additional configuration of the secondary serving cell to the terminal 1800. have. The addition or removal of the secondary serving cell corresponds to the change or update of the secondary serving cell configuration information.
  • the RRC processor 1187 determines the reconfiguration of the TAG for the terminal 1800. For example, when the TAT of a specific TAG expires, the RRC processor 1187 may reconfigure the specific TAG based on the information on the deployment environment of the network. Also, for example, the RRC processor 1187 may reconfigure the TAG based on the time advance value of the secondary serving cell obtained based on a random access procedure, and the RRC processor 1187 may uplink the secondary serving cell. If data reception is not performed for a predetermined time or the uplink synchronization of the secondary serving cell is not correct, the RRC processing unit 1187 removes the secondary serving cell from the TAG such that the secondary serving cell is included in another TAG. You can also reconfigure.
  • the RRC processor 1187 generates an RRC connection reconfiguration message including the TAG configuration information and sends the generated RRC connection reconfiguration message to the transmitter 1855.
  • the MAC processor 1872 generates and sends a PDCCH indicator to the transmitter 1855 to obtain a time advance value for uplink synchronization of the secondary serving cell.
  • the receiver 1860 receives the random access preamble from the terminal 1800 on the secondary serving cell.
  • the MAC processor 1872 may generate an activation indicator for activating the secondary serving cell and send it to the transmitter 1855 before generating the PDCCH indicator.
  • the MAC processor 1872 obtains the time advance value of the secondary serving cell to be added based on the reception time of the random access preamble, and the RRC processor 1187 determines the secondary serving cell to be added based on the time advance value as a specific TAG. Reconstruct For example, if the time advance value is the same as pTAG in the reconfigured state with pTAG upon addition of the secondary serving cell, the RRC processor 1187 does not reconstruct the TAG. Alternatively, when the time advance value is different from pTAG in the reconfigured state with pTAG and the same as another sTAG when the secondary serving cell is added, the RRC processor 1187 reconfigures the secondary serving cell to the sTAG.
  • the RRC processor 1187 reconfigures the additional secondary serving cell with a new sTAG.
  • the RRC processor 1187 generates an RRC connection reconfiguration message for informing the terminal 1800 of the reconfigured TAG and transmits the generated RRC connection reconfiguration message to the transmitter 1855.
  • the PDCCH indication may be transmitted to the terminal 1800 through the transmitter 1855 without having to wait for the random access procedure to finish.
  • the RRC processing unit 1872 transmits an RRC connection reconfiguration message or receives an RRC reconfiguration completion message
  • the MAC processing unit 1872 considers the random access procedure to be suspended and instructs the start of a new random access procedure.
  • the PDCCH indication may be transmitted to the transmitter 1855.
  • the MAC processor 1872 may add the newly added TAG.
  • the activation indicator may not be transmitted to the terminal 1800 through the transmitter 1855 in the secondary serving cell constituting the TAG for which uplink synchronization is not secured. That is, even if the secondary serving cell constituting the newly added TAG (or TAG for which uplink synchronization is not secured) is deactivated, the MAC processing unit 1872 may not transmit the activation indicator.
  • the secondary serving cell constituting the newly added TAG may be performed by the RRC processor 1811 of the terminal 1800 without an activation instruction by the MAC processor 1872 of the base station 1850. Is activated or reactivated by Therefore, in this case, the MAC processing unit 1872 of the base station 1850 generates a PDCCH indication indicating the start of the random access procedure on the secondary serving cell constituting the newly added TAG without an activation instruction and transmits it to the transmission unit 1855. Can be.
  • the MAC processor 1872 when the RRC processor 1187 transmits an RRC connection reconfiguration message or receives an RRC reconfiguration complete message, the MAC processor 1872 includes the newly added TAG (or TAG without uplink synchronization).
  • the secondary serving cell may be considered activated, and a PDCCH indication indicating the start of the random access procedure may be transmitted to the transmitter 1855.

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Abstract

La présente invention concerne les communications sans fil, et plus spécifiquement un procédé et un appareil de commande d'un groupe d'avance temporelle dans un système à multiples porteuses élémentaires. La présente invention porte sur un terminal servant à acquérir au moins deux synchronisations de liaison montante différentes dans le système à multiples porteuses élémentaires. Le terminal comprend : une unité de traitement de commande d'accès au support (MAC) pour commander l'envoi d'un préambule d'accès aléatoire (RA) utilisé pour acquérir une valeur d'avance temporelle servant à synchroniser une liaison montante d'une cellule de desserte secondaire (SCell) ; une unité d'émission pour envoyer le préambule d'accès aléatoire à une station de base ; une unité de réception pour recevoir, en provenance de la station de base, des informations de constitution de groupe d'avance temporelle (TAG) comprenant un identificateur de TAG pour la cellule de desserte secondaire ; et une unité de traitement de commande des ressources radio (RRC) pour déterminer une modification de l'identificateur de TAG pour la cellule de desserte secondaire sur la base des informations de constitution de TAG, l'unité de traitement MAC arrêtant la procédure d'accès aléatoire lorsque l'identificateur de TAG pour la cellule de desserte secondaire est modifié durant la procédure d'accès aléatoire dans la cellule de desserte secondaire.
PCT/KR2013/002200 2012-05-04 2013-03-18 Procédé et appareil de commande de groupe d'avance temporelle dans un système à multiples porteuses élémentaires WO2013165093A1 (fr)

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US11191044B2 (en) 2014-08-05 2021-11-30 Qualcomm Incorporated Timing alignment procedures for dual PUCCH
CN107889270A (zh) * 2016-09-30 2018-04-06 北京信威通信技术股份有限公司 一种随机接入的方法、装置及系统
CN109964514A (zh) * 2017-11-01 2019-07-02 北京小米移动软件有限公司 定时提前组标识的设置、配置方法及装置和用户设备
US11445461B2 (en) 2017-11-01 2022-09-13 Beijing Xiaomi Mobile Software Co., Ltd. Method and device for setting time advance group identifier, method and device for configuring time advance group identifier, and user equipment

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