WO2013013539A1

WO2013013539A1 - Random access method and user equipment

Info

Publication number: WO2013013539A1
Application number: PCT/CN2012/076782
Authority: WO
Inventors: 张健; 陈中明
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-07-25
Filing date: 2012-06-12
Publication date: 2013-01-31
Also published as: CN102905387B; CN102905387A

Abstract

The present invention provides a random access method and a user equipment (UE). The method comprises: a UE activating a secondary serving cell (SCell) in a deactivated state; and the UE performing a random access procedure in the SCell. By means of the present invention, the UE is used to activate the SCell in the deactivated state to perform the random access procedure, so that the problem that relevant steps of the random access procedure on the SCell cannot be performed normally since the SCell may be in the deactivated state is solved, and therefore, the UE can flexibly select the time of initiating the random access on the SCell, thereby improving the success rate of the random access procedure of the UE.

Description

Random access method and user equipment

The present invention relates to the field of communications, and in particular to a random access method and user equipment. BACKGROUND In a wireless cellular communication system, a random access procedure (RRC User Procedure) for an idle state (RRC_IDLE) initially accesses a network, or a connection state (RRC_CO NECTED) The terminal performs uplink synchronization with the network and acquires resource allocation for subsequent data communication. Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as the Evolved Universal Terrestrial Radio Access Network (LTE), in the 3GPP (Third Generation Partnership Project) Long Term Evolution (LTE) system In the type of base station eNB, the following six events can trigger the random access procedure of the terminal: (1) idle state initial access; (2) RRC Connection Re-establishment procedure; (3) handover (HO, Handover); (4) RRC connection state downlink data arrival requires a random access procedure, for example, when the uplink synchronization state is "unsynchronized"; (5) RRC connection state uplink data arrival requires a random access procedure, for example, when The uplink synchronization status is "non-synchronized" or there is no physical uplink control channel (PUCCH, Physical Uplink Control Channel) resource transmission scheduling request (SR, Schedule Request); (6) the RRC connection status requires a random access procedure for the purpose of positioning. For example, UE positioning requires Timing Advance. The random access process has two different forms: Contention Based (for the first five events mentioned above); Non-Contention Based (for the above (3), (4), (6) Event). After the random access procedure is successful, normal downlink or uplink transmission can be performed. The random access procedure may be initiated by a physical downlink control channel signaling (PDCCH order) or a media access control layer (MAC) of the UE, optionally, a PDCCH order or a radio resource control (RRC, Radio Resource Control). The signaling may allocate a dedicated random access preamble to the UE, and the random access procedure is a non-contention based manner; otherwise, the UE needs to select a random access preamble, and the random access procedure is a contention based manner. Selecting a random access resource by the UE includes selecting a time-frequency domain resource such as a random access preamble and a physical random access channel (PRACH). The random access process may take one or more times to succeed, or it may reach the maximum number of times but it has not been successful. eNB The preamble transmission preamble transmission maximum number (preambleTransMax) parameter is pre-configured for the UE by using system information 2 (SIB2). The contention based random access procedure is shown in FIG. 1 . The method includes the following steps: Step S102: The terminal sends a random access preamble (RACH) through the random access channel (RACH). Step SI 04, the medium access control layer (MAC) of the base station (eNB) generates a random access response message, and sends the message to the terminal in a downlink shared channel (DL-SCH, Downlink-Shared Channel); a random access preamble identifier (RAPID), a time alignment information (TA, Time Alignment), an initial uplink grant (UL Grant, Uplink Grant), and a temporary cell-temporary network temporary identifier (Temporary C-RNTI); The message is indicated by a random access-Radio Network Temporary Identifier (RA-RNTI) on the Physical Downlink Control Channel (PDCCH); Step S106, the terminal shares the transport channel in the uplink The first scheduled transmission (UL-SCH, Uplink-Shared Channel) is sent; the content of the message includes at least a Cell-Radio Network Temporary Identity (C-RNTI) Media Access Control Element (MAC Control Element) or Common Control Logical Channel Service Data Unit (CCCH SDU); the message is sent to support mixing ReQuest (HARQ, Hybrid Automatic Retransmission request). Step S108: The base station sends a contention resolution message on the DL-SCH; the message is indicated by a C-RNTI or a temporary C-RNTI on the PDCCH; the sending of the message supports HARQ. As shown in FIG. 2, the non-contention based random access procedure includes three steps. Step S202: The base station allocates a random access preamble to the terminal by using downlink dedicated signaling. The signaling is generated by the target base station in the case of handover and sent by the source base station to the terminal by using a handover command (HO Command); when the downlink data arrives, the PDCCH is transmitted to the terminal; in step S204, the terminal passes the random access channel in the uplink ( RACH) transmitting the allocated non-contention random access preamble (Synchronous Access Preamble); Step S206: The base station transmits a random access response message (Random Access Response) on the downlink shared transport channel (DL-SCH). The message includes at least time adjustment information and a random access preamble identifier, and the handover further includes initial uplink grant information; the message is indicated by a random access-radio network temporary identifier (RA-RNTI) on the PDCCH. In the Long Term Evolution Advanced (LTE-A) system, the Long-Term Evolution Advanced (LTE-A) system version 10 (Rel-10) Carrier Aggregation (CA) is in the downlink and / or up to five component carriers (CC) are aggregated to support a maximum transmission bandwidth of 100 MHz, respectively, and the total configuration of UL CCs is less than or equal to the total configuration of DL CCs. The user equipment (UE) is configured with a downlink primary carrier (DLPCC) and an uplink primary carrier (ULPCC). The downlink secondary carrier (Downlink Secondary CC, DL SCC) can be configured. ) and / or 0 ~ 4 uplink secondary carrier (ULSCC). The cell (Cell) in which the UE initially accesses or handovers is called a primary serving cell (PCell), and is composed of a DL PCC and a UL PCC, and the DL PCC and the UL PCC are associated by the information indicated in the System Information Broadcast 2 (SIB2). . The base station may add a new cell configuration to the UE by using Radio Resource Control (RRC) signaling due to the increase of the UE service traffic or the radio resource management (RRM) requirement of the base station (eNB). A cell is called a secondary serving cell (SCell), and is composed of DL SCC and B UL SCC associated with SIB2, or only DL SCC. The UE may use the RRC signaling to delete the cell that has been configured to the UE, including the uplink and downlink carriers of the deleted cell, because the UE traffic is reduced, or the cell signal quality of the cell currently configured to the UE is deteriorated, or the RRM management of the base station is performed. Configuration information. The above process of adding and deleting cell configurations can occur at the same time. From the perspective of UE power saving and CC management, the base station (eNB) can activate/deactivate an SCell through the MAC CE, and the PCell cannot be activated/deactivated. The UE does not monitor the physical downlink control channel (PDCCH), does not receive the physical downlink shared channel (PDSCH), does not perform channel quality indication (CQI), precoding matrix indication (PMI), and hierarchical indication (RI) on the deactivated SCell. Equal Channel State Indication (CSI) related measurements, mobility-related measurements, non-physical uplink shared channel (PUSCH) transmit data, no Sounding Reference Symbols (SRS), may also include for radio frequency (RF) ) such as closing or adjusting. After the SCell is activated, the UE can monitor the PDCCH, receive the PDSCH, perform CSI-related measurements such as CQI/PMI/RI, and perform operations such as transmitting data and transmitting SRS on the PUSCH, and may also include operations such as turning on or adjusting the RF.

The LTE-A Rel-10 CA supports a single TA (Timing Alignment) and supports random access procedures only on the PCell. LTE-A Rel-11 CA supports multiple TAs. For inter-band and RRH (remote radio unit), the uplink TAs of each cell participating in the aggregation may be different. The random access procedure on the SCell needs to be supported to separate Get the respective TA. For the same PC group or SCell, the same can be attributed to the same TA group. The synchronization status of the PCell or SCell in the same TA group is the same. Both are in the uplink synchronization state or are in the uplink out-of-synchronization state. If PCell or SCell needs to obtain uplink synchronization in the case of out-of-step, only If the random access procedure is successfully performed on one of the PCells or SCells, the uplink synchronization succeeds for the TA group. The UE may determine whether the PCell and/or the SCell are in a synchronized or out-of-synchronized state according to whether the TA timer maintained by the UE times out. Different TA groups can be maintained by using the same TA timer. When the TA timer expires, the PCells and SCells in all TA groups are considered to be out of synchronization. Different TA groups can be maintained with different TA timers. The corresponding TA timer timeout means that the PCell and SCell in the corresponding TA group are out of synchronization. If the UE does not perform data transmission and reception for a long period of time, the SCell may be in the deactivated state, and the PDCCH may not be monitored and the uplink data may be sent on the PUSCH, so that the related steps of the random access procedure on the SCell cannot be performed normally. SUMMARY OF THE INVENTION The present invention provides a random access method and a user equipment, to at least solve the above-mentioned steps of the random access process on the SCell, because the UE does not perform data transmission and reception for a long period of time, and the SCell may be in a deactivated state. The problem could not be performed normally. According to an aspect of the present invention, a random access method is provided, including: a UE activating a secondary serving cell SCell in a deactivated state; and performing a random access procedure on the SCell. Preferably, the UE activates the secondary serving cell SCell in the deactivated state, including: if the UE is in the uplink synchronization state in the primary serving cell PCell, the UE activates the SCell. Preferably, the UE activates the secondary serving cell SCell in the deactivated state, including: if the UE performs a random access procedure in the primary serving cell PCell, the UE activates after the random access procedure on the PCell or after the UE sends the msg3 on the PCell. SCell. Preferably, the UE activates the secondary serving cell SCell in the deactivated state, including: for the random access procedure triggered by the uplink data arrival, the UE activates the SCell when the value of the buffer status report BSR is greater than a preset first threshold. Preferably, the UE activates the secondary serving cell SCell in the deactivated state, including: for the random access procedure triggered by the uplink data arrival, the UE activates the SCell when the value of the power headroom report PHR is greater than a preset second threshold. Preferably, the UE activates the secondary serving cell SCell in the deactivated state, including: for the random access procedure triggered by the uplink data arrival, the UE activates the SCell when the value of the downlink path loss is less than a preset third threshold. Preferably, the UE activates the secondary serving cell SCell in the deactivated state, including: for the random access procedure triggered by the uplink data arrival, the UE reports that the value of the BSR is greater than a preset first threshold in the buffer status, and the UE The SCell is activated when the value of the power headroom report PHR is greater than the preset second threshold or the downlink path loss of the UE is less than the preset third threshold. Preferably, the UE activates the secondary serving cell SCell in the deactivated state, including: the UE activates the SCell according to the MAC CE sent by the eNB on the primary serving cell PCell. Preferably, the eNB separately sends the MAC CE to the UE or multiplexes with other MAC SDUs and sends the information to the UE.

The UE is multiplexed with the msg4 of the random access procedure on the PCell and then sent to the UE. Preferably, before performing the random access procedure on the SCell, the UE further includes: the eNB sending a dedicated random access preamble on the PDCCH. Preferably, the eNB sends the dedicated random access preamble on the PDCCH, where the eNB determines whether the value of the buffer status report BSR received on the PCell is greater than a preset fourth threshold; if yes, the eNB passes the PDCCH on the SCell. Send a dedicated random access preamble. Preferably, the eNB sends the dedicated random access preamble on the PDCCH, where: the eNB determines whether the buffer data amount of the downlink data of the UE is greater than a preset fifth threshold; if yes, the eNB sends the dedicated random access by using the PDCCH on the SCell. Leading. According to another aspect of the present invention, a user equipment is provided, including: an activation module, configured to activate a secondary serving cell SCell in a deactivated state; and a random access module configured to perform a random access procedure on the SCell. Preferably, the activation module is further configured to activate the SCell if the UE is in an uplink synchronization state in the primary serving cell PCell. Preferably, the activation module is further configured to activate the SCell after the random access procedure on the PCell is successful or after sending the msg3 on the PCell in the case that the UE performs a random access procedure in the primary serving cell PCell. Preferably, the activation module is further configured to perform a random access procedure triggered by the uplink data arrival, and if the value of the buffer status report BSR is greater than a preset first threshold, the SCell is activated. Preferably, the activation module is further configured to perform a random access procedure triggered by the uplink data arrival, and if the value of the power headroom report PHR is greater than a preset second threshold, the SCell is activated. Preferably, the activation module is further configured to perform a random access procedure triggered by the uplink data arrival, and activate the SCell if the value of the downlink path loss is less than a preset third threshold. Preferably, the activation module is further configured to activate the SCell according to the MAC CE sent by the eNB on the primary serving cell PCell. With the present invention, the UE activates the deactivated SCell to perform a random access procedure, which solves the problem that the SCell may be in a deactivated state, and the related steps of the random access procedure on the SCell cannot be performed normally, so that the UE can flexibly select The timing of random access is initiated on the SCell, thereby improving the success rate of the UE random access procedure. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a flowchart of a contention-based random access procedure according to the related art; FIG. 2 is a flow chart of a non-contention based random access procedure according to the related art; FIG. 3 is a random diagram according to an embodiment of the present invention. FIG. 4 is a flowchart of a random access procedure according to Embodiment 1 of the present invention; FIG. 5 is a flowchart of a random access procedure according to Embodiment 2 of the present invention; FIG. 6 is a flowchart according to Embodiment 3 of the present invention; FIG. 7 is a flowchart of a random access procedure according to Embodiment 4 of the present invention; and FIG. 8 is a structural block diagram of a user equipment according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. FIG. 3 is a flowchart of a random access method according to an embodiment of the present invention. As shown in FIG. 3, the method includes the following steps: Step S302: A UE activates a secondary serving cell SCell in a deactivated state. Step S304, the UE performs a random access procedure on the SCell. In this embodiment, the UE performs the random access procedure by activating the SCell in the deactivated state, which solves the problem that the SCell may be in a deactivated state, and the related steps of the random access procedure on the SCell cannot be performed normally, so that the UE can The timing of initiating random access on the SCell is flexibly selected, thereby improving the success rate of the UE random access procedure. In step S302, the UE activates the SCell or activates the SCell according to the MAC CE sent by the eNB on the PCell. The behavior of the UE activating the SCell is consistent with the behavior of the UE activating the SCell after receiving the MAC CE from the eNB, including: the UE can monitor the PDCCH, receive the PDSCH, perform CSI-related measurements such as CQI/PMI/RI, and send data and send SRS on the PUSCH. Such operations may also include operations such as RF turning on or adjusting. If the UE is in the uplink synchronization state on the PCell, the UE activates the SCell. If the UE performs the random access procedure in the PCell, the UE activates the SCell after the random access procedure on the PCell succeeds; and is applicable to the contention-based random access procedure and the non-contention-based random access procedure on the PCell; or, the UE Activate SCell after sending msg3 on PCell. The UE activates the SCell when the value of the buffer status report (BSR) is greater than a preset threshold for the random access procedure triggered by the uplink data arrival. The UE activates the SCell when the value of the power headroom report (PHR) is greater than a preset threshold for the random access procedure triggered by the uplink data arrival. The UE activates the SCell when the value of the downlink path loss (DL pathloss) is less than the preset threshold for the random access procedure triggered by the uplink data arrival. The value of the buffer status report (BSR) of the UE is greater than the preset threshold, and the PHR of the UE is greater than another preset threshold or the downlink path loss is less than another preset threshold. , activate SCell. When the UE activates the SCell according to the MAC CE sent by the eNB on the PCell, the MAC CE may be separately sent to the UE or multiplexed with other MAC SDUs and then sent to the MAC CE, or multiplexed with the msg4 of the random access procedure on the PCell and then sent. Give the UE. After the UE activates the SCell, the UE actively performs a random access procedure, or waits for the eNB to send a dedicated random access preamble on the PDCCH to perform a random access procedure. The eNB performs a random access procedure by sending a dedicated random access preamble through the PDCCH on the SCell according to the value of the BSR received on the PCell being greater than the preset threshold. The eNB sends a dedicated random access preamble through the PDCCH to perform a random access procedure on the SCell when the buffer data volume of the downlink data of the UE is greater than a preset threshold. In this embodiment, when the random access procedure is performed, the step of the random access procedure is the same as the contention-based random access procedure or the non-contention-based random access procedure in the prior art. In the following Embodiments 1, 2, and 3 of the present invention, one PCell, SCelll, and SCell2 are configured by the UE, and the uplink TAs of SCelll, SCell2, and PCell are different, for example, they are located in different bands and/or RRHs are configured. SCelll is the same as the TA of SCell2 and is located in the same TA group. The present invention is also applicable to a scenario in which the UE is configured with one PCell and one or more SCells. When the TAs of different SCells are the same, they are located in the same TA group, and the TAs of different SCells are different in different TA groups. The SCell may be in the same TA group as the PCell. If the PCell or the SCell is in a different TA group, if the corresponding TA group is out of synchronization, if there is a need to obtain uplink synchronization, random access is required. process. The scenario of this embodiment is as follows: The PCell of the UE is in an uplink synchronization state; the SCelll and the SCell2 are in an uplink out-of-synchronization state, and are all deactivated; the UE uplink data arrives. FIG. 4 is a flowchart of a random access procedure according to the first embodiment of the present invention. As shown in FIG. 4, the method includes the following steps: Step S402: The UE activates at least one of SCel11 and SCell2 to activate SCelll as an example; or the UE determines When the value of the BSR is greater than the pre-configured threshold X, the SCelll is activated; or the UE determines that the value of the PHR is greater than the pre-configured threshold y, and activates the SCelll; or the UE determines that the value of the BSR is greater than the pre-configured threshold x and the value of the PHR is greater than the pre-configuration When the threshold y is activated, SCelll is activated. Or the UE sends a BSR on the PCell, and waits for the eNB to send the MAC CE to activate SCelll on the PCell. In this step, further, when the value of the BSR is greater than the pre-configured threshold X, the eNB sends a dedicated random access preamble to perform a non-contention based random access procedure. Step S404, the UE performs a contention-based random access procedure on the SCel11, and the steps of the UE random access procedure are the same as the prior art. Or the UE sends a BSR on the PCell (if the UE sends the BSR in step 1, the BSR does not need to be sent again), and waits for the eNB to send a dedicated random access preamble to trigger the non-contention based random access procedure in the SCelll, and the UE randomly The steps of the access process are the same as in the prior art. In this step, further, the eNB is a BSR. When the value of the value is greater than the pre-configured threshold X, the non-contention-based random access procedure is performed by the SCelll transmitting a dedicated random access preamble. The scenario in this embodiment is as follows: The PCell of the UE is in an uplink synchronization state; the SCelll and the SCell2 are in an uplink out-of-synchronization state, and are all deactivated; the downlink data for the UE in the eNB arrives. FIG. 5 is a flowchart of a random access procedure according to Embodiment 2 of the present invention. As shown in FIG. 5, the method includes the following steps: Step S502: An eNB sends a MAC CE that activates SCelll through a PCell of the UE. Step S504, the UE receives the MAC CE in the PCell, activates SCel11, and monitors the PDCCH on the SCel11. Step S506, the eNB sends a dedicated random access preamble on the SCel11 to perform a non-contention based random access procedure, and the steps of the random access procedure are the same as the prior art. In the steps S504 and S506, when the buffer data volume of the downlink data of the UE is greater than the preset threshold X, the eNB sends a dedicated random access preamble to perform a random access procedure on the SCel11. The scenario of the embodiment is as follows: the PCell of the UE is in the uplink out-of-synchronization state; the SCelll and the SCell2 are in the uplink out-of-synchronization state, and both are deactivated, and the UE uplink data arrives. FIG. 6 is a flowchart of a random access procedure according to Embodiment 3 of the present invention. As shown in FIG. 6, the method includes the following steps: Step S602: A UE performs a contention-based random access procedure on a PCell. Step S604, the UE activates the SCelll after the contention success on the PCell; or the UE activates the SCelll after sending the msg3 on the PCell; or the UE activates the SCelll after sending the random access preamble on the PCell; or at the above three timings, when the UE judges When the value of the BSR is greater than the pre-configured threshold X, SCelll is activated; or when the UE determines that the value of the PHR is greater than the pre-configured threshold y, the SCelll is activated; or the UE determines the BSR at the above three timings respectively. SCelll is activated when the value is greater than the pre-configured threshold X and its PHR value is greater than the pre-configured threshold y. In the case that the UE does not activate the SCel11, the step S604 includes: the eNB multiplexes the MAC CE to activate the SCel11 in the PCG random access procedure; or the eNB sends the MAC CE to activate the SCelll on the PCell after the PCell random access result; or After the PCell uplinks, the UE sends a BSR on the PCell, and waits for the eNB to send the MAC CE to activate the SCelll on the PCell. Step S606, the UE performs a contention-based random access procedure on the SCel11, and the step of the UE random access procedure is the same as the prior art; or the UE sends the BSR on the PCell after the PCell uplinks synchronization (if the UE sends in step 1) The BSR, the BSR is not required to be sent here, and the eNB waits for the dedicated random access preamble to trigger the non-contention based random access procedure in the SCelll. The steps of the UE random access procedure are the same as the prior art. In this step, further, when the value of the BSR is greater than the pre-configured threshold X, the eNB sends a dedicated random access preamble to perform a non-contention based random access procedure. The scenario in this embodiment is as follows: the PCell of the UE is in the uplink out-of-synchronization state; the SCelll and the SCell2 are in the uplink out-of-synchronization state, and are all deactivated; the downlink data for the UE in the eNB arrives. FIG. 7 is a flowchart of a random access procedure according to Embodiment 4 of the present invention. As shown in FIG. 7, the method includes the following steps: Step S702: An eNB sends a dedicated random access preamble through a PCell of the UE to perform non-contention based random access. process. Step S704, after the random access of the UE on the PCell is successful, the eNB sends the MAC CE to activate the SCelll through the PCell; or the eNB multiplexes the MAC CE in the msg2 of the random access procedure on the PCell to activate the SCelll. Step S706, the UE receives the MAC CE in the PCell, activates SCelll, and listens on SCelll.

PDCCH. Step S708, the eNB sends a dedicated random access preamble on the SCel11 to perform a non-contention based random access procedure, and the steps of the random access procedure are the same as the prior art. In the step S706 and the step S708, when the buffer data volume of the downlink data of the UE is greater than the preset threshold X, the eNB sends a dedicated random access preamble through the PDCCH on the SCel11 to perform a random access procedure. In the above embodiments, the threshold X of the BSR may be set to one of the indexes 0 to 63 in the BSR table or the extended BSR table supported by the UE. The PHR threshold y can be set to one of indexes 0 to 63 in the PHR table supported by the UE. FIG. 8 is a structural block diagram of a user equipment according to an embodiment of the present invention. As shown in FIG. 8, the user equipment includes an activation module 10 and a random access module 20. The activation module 10 and the random access module 20 are connected. The activation module 10 is arranged to activate the secondary serving cell SCell in the deactivated state. The random access module is set to perform a random access procedure on the SCell. In this embodiment, the random access procedure is performed by the UE activating the SCell in the deactivated state, so that

The UE can flexibly select the timing of initiating random access on the SCell, thereby improving the success rate of the UE random access procedure. The activation module 10 can be used to activate the SCell in the following scenarios: (1) If the UE is in the uplink synchronization state in the primary serving cell PCell, the SCell is activated.

(2) If the UE performs a random access procedure in the primary serving cell PCell, the SCell is activated after the random access procedure on the PCell is successful; applicable to the contention-based random access procedure and the non-contention-based random access procedure on the PCell; Or activate SCell after sending msg3 on PCell.

(3) For the random access procedure triggered by the uplink data arrival, the SCell is activated when the buffer status report BSR value is greater than the preset first threshold.

(4) For the random access procedure triggered by the uplink data arrival, the SCell is activated when the value of the power headroom report PHR is greater than the preset second threshold.

(5) For the random access procedure triggered by the uplink data arrival, the SCell is activated when the value of the downlink path loss is less than the preset third threshold. (6) For the random access procedure triggered by the uplink data arrival, the value of the BSR in the buffer status report is greater than the preset first threshold, and the value of the power headroom report PHR is greater than the preset second threshold or downlink. When the value of the loss is less than the preset third threshold, the SCell is activated.

(7) The SCell is activated according to the MAC CE sent by the eNB on the primary serving cell PCell. The foregoing embodiments of the present invention support the contention-based and non-contention-based random access procedures on the SCell, and have the advantages of low delay, small signaling overhead, and the uplink traffic and channel conditions of the UE, and enable the UE to flexibly select on the SCell. The timing of initiating random access can better adapt to the actual needs of the UE to improve data throughput, and also improve the success rate of the random access procedure. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. Perform the steps shown or described, or separate them into individual integrated circuit modules, or Multiple of these modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention. Industrial Applicability The present invention is applicable to a wireless cellular communication system, and has advantages such as low delay and low signaling overhead by supporting a contention-based and non-contention-based random access procedure on the SCell, taking into account UE uplink traffic and channel conditions. The UE can flexibly select the timing of initiating random access on the SCell, so as to better adapt to the actual requirement of the UE to improve data throughput, and also improve the success rate of the random access procedure.

Claims

Claim

1. A random access method, including:

The user equipment UE activates the secondary serving cell SCell in the deactivated state;

The UE performs a random access procedure on the SCell.

The method according to claim 1, wherein the UE activates the secondary serving cell SCell in the deactivated state, including:

If the UE is in an uplink synchronization state in the primary serving cell PCell, the UE activates the SCell.

If the UE performs a random access procedure in the primary serving cell PCell, the UE activates the SCell after the random access procedure on the PCell succeeds or the UE sends a message 3 msg3 on the PCell.

For the random access procedure triggered by the uplink data arrival, the UE activates the SCell when the value of the buffer status report BSR is greater than a preset first threshold.

For the random access procedure triggered by the uplink data arrival, the UE activates the SCell when the value of the power headroom report PHR is greater than a preset second threshold.

For the random access procedure triggered by the uplink data arrival, the UE activates the SCell when the value of the downlink path loss is less than a preset third threshold.

The method according to claim 1, wherein the UE activates the secondary serving cell SCell in the deactivated state, including: For the random access procedure triggered by the uplink data arrival, the value of the BSR in the buffer status report is greater than the preset first threshold, and the value of the power headroom report PHR of the UE is greater than the preset second threshold. When the value or the downlink loss of the UE is less than a preset third threshold, the SCell is activated.

The UE activates the SCell according to a media access control unit MAC CE sent by the evolved Node B eNB on the primary serving cell PCell.

9. The method according to claim 8, wherein the eNB separately transmits the MAC CE to the UE or multiplexes with other media access service data unit MAC SDUs, and then sends the same to the UE or The message 4 msg4 of the random access procedure on the PCell is multiplexed and sent to the UE.

The method according to claim 8, wherein before the performing the random access process on the SCell, the UE further includes:

The eNB transmits a dedicated random access preamble on the physical downlink control channel PDCCH.

11. The method of claim 10, wherein the transmitting, by the eNB, the dedicated random access preamble on the PDCCH comprises:

Determining, by the eNB, whether a value of a buffer status report BSR received on the PCell is greater than a preset fourth threshold;

If yes, the eNB sends a dedicated random access preamble through the PDCCH on the SCell.

12. The method of claim 10, wherein the transmitting, by the eNB, the dedicated random access preamble on the PDCCH comprises:

Determining, by the eNB, whether a buffer data amount of the downlink data of the UE is greater than a preset fifth threshold;

A user equipment UE, comprising: an activation module, configured to activate a secondary serving cell SCell in a deactivated state; and a random access module configured to perform a random access procedure on the SCell.

14. The user equipment according to claim 13, wherein the activation module is further configured to activate the SCell if the UE is in an uplink synchronization state in a primary serving cell PCell.

The user equipment according to claim 13, wherein the activation module is further configured to: after the random access procedure is performed on the PCell in the case that the UE performs a random access procedure in the primary serving cell PCell, Or activate the SCell after sending the message 3 msg3 on the PCell.

The user equipment according to claim 13, wherein the activation module is further configured to perform a random access procedure triggered by an uplink data arrival, where the buffer status report BSR value is greater than a preset first threshold value. , activate the SCell.

The user equipment according to claim 13, wherein the activation module is further configured to perform a random access procedure triggered by an uplink data arrival, where the value of the power headroom report PHR is greater than a preset second threshold value. , activate the SCell.

The user equipment according to claim 13, wherein the activation module is further configured to perform a random access procedure triggered by an uplink data arrival, and if the value of the downlink path loss is less than a preset third threshold, the activation is performed. Said SCell.

19. The user equipment of claim 13, wherein the activation module is further configured to activate the SCelL according to a media access control unit MAC CE sent by an evolved Node B eNB on a primary serving cell PCell