Method and system for accessing auxiliary service cell, network side network element and user equipmentTechnical Field
The present invention relates to an access technology of an auxiliary serving cell, and in particular, to a method and a system for efficiently accessing an auxiliary serving cell, a network element on a network side, and a user equipment.
Background
In a wireless cellular communication system, a Random Access Procedure (Random Access Procedure) is used for a terminal in an IDLE state (RRC _ IDLE) (or called User Equipment (UE)) to initially Access a network, or a terminal in a CONNECTED state (RRC _ CONNECTED) performs Uplink synchronization (Uplink synchronization) and resource allocation with the network to perform subsequent data communication.
In an evolved universal Terrestrial Radio Access Network (E-UTRAN) of the Third Generation Partnership Project (3 GPP) Long Term Evolution (LTE) system, the following six events may trigger a random Access procedure of a UE: (1) the idle state is initially accessed; (2) a radio resource control Connection reestablishment procedure (RRC Connection Re-estimation procedure); (3) handover (HO, Handover); (4) the downlink data arrival in the RRC connected state requires a random access process, for example, when the uplink synchronous state is "asynchronous"; (5) a random access process is required for Uplink data arrival in an RRC connection state, for example, when an Uplink synchronization state is "asynchronous" or there is no available Physical Uplink Control Channel (PUCCH) resource sending Scheduling Request (SR); (6) the RRC connected state requires a random access procedure for positioning purposes, e.g. Timing Advance (Timing Advance) for UE positioning. The random access procedure has two different forms: conflict-Based (content Based) (applicable to the first five events above); non-collision Based (Non-collision Based) (applicable to the above-mentioned events (3), (4), and (6)). After the random access process is successful, normal downlink or uplink transmission can be performed.
The Random Access process may be initiated by a physical downlink Control channel (PDCCH order) or a media Access Control layer (MAC) of the UE, and optionally, the PDCCH order or a Radio Resource Control (RRC) signaling may allocate a dedicated Random Access preamble (Random Access preamble) to the UE, where the Random Access process is in a non-collision based manner; otherwise, the UE needs to select the random access preamble, and the random access process is based on a collision mode. The UE selects the Random Access resource includes selecting a Random Access preamble and a time-frequency domain resource of a Physical Random Access Channel (PRACH), and the like. For non-conflicting random access procedures, there is no conflict resolution procedure. Fig. 1 is a schematic diagram of a conventional random access procedure, and as shown in fig. 1, a Contention based random access process mainly includes the following steps:
step 101, the UE sends a Random Access Preamble (Random Access Preamble) through a Random Access CHannel (RACH) in uplink; the time for sending the random access preamble by the UE is configured in the system message broadcast, and the main configuration is frequency domain and time domain resources, where the frequency domain is configured with PRACH-FreqOffset (frequency offset of PRACH), and the time domain is configured with PRACH-ConfigIndex (which subframes on which frames on the PRACH can send the random access preamble).
Step 102, a Media Access Control (MAC) layer of a base station (eNB) generates a random Access response message and sends the random Access response message to a UE on a Downlink Shared Channel (DL-SCH); the Random Access response message at least includes a Random Access Preamble IDentifier (RAPID), Time Alignment (TA) information, an initial Uplink Grant (UL Grant), and a Temporary cell-radio network Temporary IDentifier (Temporary C-RNTI); the Random Access response message is indicated by a Random Access-Radio Network Temporary Identifier (RA-RNTI) on a Physical Downlink Control CHannel (PDCCH);
step 103, the UE sends a first Scheduled Transmission (Scheduled Transmission) message on an Uplink Shared Channel (UL-SCH); the content of the scheduled transmission message at least comprises a cell-radio network temporary identifier (C-RNTI), a media access Control Element (MAC Control Element) or a common Control logic channel service data unit (CCCH SDU) comprising a conflict Resolution identifier (content Resolution Identity); the transmission of the scheduled transmission message supports Hybrid Automatic repeat request (HARQ);
step 104, the base station sends a conflict Resolution message (context Resolution) on the DL-SCH; the conflict resolution message is indicated by C-RNTI or temporary C-RNTI on PDCCH, and can comprise a conflict resolution identifier; the transmission of the message supports HARQ.
The above steps 103 and 104 are used to resolve the conflict. In the six events for triggering the random access procedure of the UE, among the six events, (4) the random access procedure is required when the RRC connection state downlink data arrives, and (5) the random access procedure is required when the RRC connection state uplink data arrives, the Scell is triggered to execute the random access procedure, but the random access procedure is triggered to execute when other events trigger the Scell to execute the random access procedure, such as activation of the Scell, is not excluded.
In order to provide a higher data rate for a mobile user, a Long Term evolution advanced (LTE-a) system proposes a Carrier Aggregation (CA) technique, which aims to provide a UE with a corresponding capability with a larger bandwidth data transmission and improve a peak rate of the UE. In the LTE system, the maximum downlink transmission bandwidth supported by the system is 20MHz, carrier aggregation is to aggregate two or more Component Carriers (CCs) to support a transmission bandwidth greater than 20MHz and not more than 100MHz at most, and the total number of UL CCs in the initial stage is configured to be less than or equal to the total number of DL CCs. An LTE-a UE with carrier aggregation capability can simultaneously transmit and receive data on multiple component carriers, and the UE referred to below refers to such UE unless otherwise specified. In the LTE-a system, after entering a connected state, a UE may communicate with a source base station through multiple Component carriers (e.g., CC1, CC2) at the same time, and the base station may assign a Primary Component Carrier (PCC) to the UE through explicit configuration or according to a protocol agreement, where other Component carriers are called Secondary Component Carriers (SCCs), a serving Cell on the PCC is called a Primary serving Cell (Pcell, PrimaryCell), and a serving Cell on the SCC is called a Secondary serving Cell (Scell, Secondary Cell). The secondary serving cell is configured by the base station after the UE enters the connected state. Generally, a certain serving cell has symmetric uplink and downlink (Scell may only configure downlink), and it is explicitly indicated in the system information block SIB2 that, in order to avoid interference of a control channel, a concept of cross-carrier scheduling is introduced, that is, when PDCCH interference of a certain Scell is severe, PDCCH of the Scell is not enabled, but PDSCH of the Scell is scheduled through another serving cell, where another serving cell may be configured through RRC signaling. The base station allocates only one C-RNTI for the UE, i.e. the C-RNTI of each serving cell is the same.
According to Rel10, in the initial stage of carrier aggregation, the number of scells is as small as only 1, and the scenario is limited to not support uplink RRH and repeat, so that there is only one TA, and the UE only needs to initiate uplink synchronization on the Pcell, but not on the Scell. In the subsequent stage, due to the increase of the data volume of the Scell, the number of the scells is increased to 4, the scenario is also relaxed to support uplink RRH and repeat, and at this time, one TA cannot solve the problem, so that a plurality of TAs are introduced. At this time, uplink synchronization is also initiated on the Scell, and the random access process is executed after activation of the Scell, and the Scell must perform normal uplink data transceiving after the uplink synchronization is completed. If the non-conflicting random access procedure is performed on the Scell, the time is relatively short, and if the conflicting random access procedure is performed, the time is relatively long. In order to improve user experience, it is necessary to shorten a conflicting random access procedure or to speed up the Scell sending uplink data.
Disclosure of Invention
In view of this, the main objective of the present invention is to provide a method and a system for accessing a secondary serving cell, a network element at a network side, and a user equipment, which can enable an Scell to quickly implement access when the Scell needs to be used.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
a method for secondary serving cell access, comprising:
user Equipment (UE) sends uplink data or a random access preamble to a network side through an auxiliary serving cell at an uplink data or random access preamble sending time notified by the network side;
and after receiving the time adjustment TA fed back by the network side, the UE completes the access of the auxiliary service cell.
Preferably, the TA is calculated and fed back by the network side according to the random access preamble or the uplink data sent by the UE.
Preferably, the uplink data or the random access preamble is sent at the earliest random access preamble or uplink data sending opportunity determined by the network side for the UE.
Preferably, the timing for transmitting the uplink data or the random access preamble is a subframe which satisfies the timing condition for transmitting the uplink data or the random access preamble in the current frame or the next frame.
Preferably, the method further comprises:
the UE receives the notification of the opportunity of sending the uplink data or the random access preamble and the notification of the activation command of the secondary serving cell, which are sent together by the network side; or, the UE receives a notification of the timing for transmitting the uplink data or the random access preamble, which is sent by the network side after sending the activation command of the secondary serving cell.
Preferably, the method further comprises:
the UE determines that different TAs are required to be adopted by the auxiliary serving cell and the main serving cell;
or, the UE receives a notification that the secondary serving cell and the primary serving cell need to adopt different TAs, where the notification is sent by the network side.
Preferably, the method further comprises:
and the UE informs the network side of needing to activate the auxiliary service cell or needing to acquire the TA of the auxiliary service cell through the main service cell.
Preferably, the network side is a base station.
A method for secondary serving cell access, comprising:
the network side informs the UE of the opportunity of sending uplink data or random access preamble;
and after receiving the uplink data or the random access preamble sent by the UE through the auxiliary service cell, the network side calculates a TA and feeds the TA back to the UE so that the UE is accessed to the auxiliary service cell.
Preferably, the uplink data or the random access preamble is sent at the earliest random access preamble or uplink data sending opportunity determined by the network side for the UE.
Preferably, the method further comprises:
the network side sends a notice of the opportunity of sending the uplink data or the random access preamble and a notice of an activation command of the secondary serving cell to the UE together; or, the network side sends a notification of the timing for sending the uplink data or the random access preamble to the UE after sending the activation command of the secondary serving cell.
Preferably, the method further comprises:
and the network side informs the UE that the auxiliary service cell and the main service cell need to adopt different TAs.
A system for accessing a secondary service cell comprises a UE and a network side, wherein,
the network side is used for calculating TA according to the received random access preamble or uplink data and sending the TA to the UE; and informing the UE of the opportunity of sending uplink data or random access preamble;
the UE is used for sending the random access preamble or the uplink data to the network side through the auxiliary serving cell at the time of sending the uplink data or the random access preamble; and completing the access of the auxiliary service cell after receiving the TA.
Preferably, the uplink data or the random access preamble is sent at the earliest random access preamble or uplink data sending opportunity determined by the network side for the UE.
Preferably, the uplink grant occasion is a subframe which satisfies the occasion condition of sending the uplink data or the random access preamble in the current frame or the next frame.
Preferably, the network side is further configured to send, to the UE, a notification of the occasion for sending the uplink data or the random access preamble together with a notification of an activation command for the secondary serving cell;
or, after the notification of the activation command of the secondary serving cell, sending a notification of an opportunity to transmit uplink data or a random access preamble to the UE.
Preferably, the UE is further configured to determine that the secondary serving cell and the primary serving cell need to use different TAs;
or, the network side is further configured to notify the UE that the secondary serving cell and the primary serving cell need to use different TAs.
Preferably, the UE is further configured to,
and informing the network side of activating the auxiliary service cell or acquiring the TA of the auxiliary service cell through the main service cell.
A network side network element comprises a determining unit, a receiving unit, a calculating unit and a sending unit; wherein,
a determining unit, configured to determine, for the UE, an occasion to send uplink data or a random access preamble;
a receiving unit, configured to receive a random access preamble or uplink data sent by a UE;
a calculation unit for calculating TA;
a sending unit, configured to send the TA to the UE; and sending the uplink data or random access preamble sending time to the UE.
Preferably, the determining unit is further configured to determine an earliest random access preamble or uplink data transmission opportunity for the UE; the uplink grant time is a subframe which meets the time condition of sending uplink data or random access preamble in the current frame or the next frame.
A user equipment comprises a sending unit and an access unit, wherein,
a sending unit, configured to send a random access preamble or uplink data to a network side through an auxiliary serving cell at an uplink data or random access preamble sending time notified by the network side;
and the access unit is used for completing the access of the auxiliary service cell after receiving the TA sent by the network side.
In the invention, when the base station determines the uplink authorization time or the time for sending the preamble for the Scell of the UE, the uplink access time as early as possible is selected instead of the common time (such as the 1 st subframe of each frame) for sending the uplink access preamble for the UE, so that the UE does not need to wait for a long enough time to access the Scell. The invention enables Scell access of the UE to be quicker, and can provide Scell access for the UE as soon as possible when the service load of the UE is heavier.
Drawings
Fig. 1 is a schematic diagram of a conventional random access procedure;
FIG. 2 is a flowchart of a method for accessing a secondary serving cell according to the present invention;
fig. 3 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention;
fig. 4 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention;
fig. 5 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention;
fig. 6 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention;
fig. 7 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a network element on a network side according to an embodiment of the present invention;
fig. 9 is a schematic structural diagram of a user equipment according to an embodiment of the present invention.
Detailed Description
The basic idea of the invention is as follows: when the base station determines the uplink authorization sending time or the random access preamble sending time for the Scell of the UE, the base station selects the uplink access time as early as possible instead of the common time (such as the 1 st subframe of each frame) when the UE sends the uplink access preamble, so that the UE does not need to wait for a long enough time to access the Scell.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings by way of examples.
Fig. 2 is a flowchart of a method for accessing a secondary serving cell according to the present invention, and as shown in fig. 2, the method for accessing a secondary serving cell mainly includes the following steps:
step 201, UE sends random access preamble or uplink data to a base station;
step 202, the base station calculates a TA according to the received random access preamble or uplink data, and feeds back the TA to the UE, and after the UE acquires the TA, the UE can normally receive and transmit data in the cell. The base station may also feed back an initial uplink Grant (UL Grant) to the UE together with the TA.
The essence of the technical solution of the present invention is further clarified by specific examples below.
The following embodiments of the present invention are applied in the scenario that in the LTE-a system, the base station 1 is a base station with carrier aggregation capability. Base station 1 polices two cells, Cell1 and Cell2 respectively. Some or all of the two cells may provide the user equipment with the capability of carrier aggregation to extend the bandwidth of the transmission. The UE1 accesses the network through the base station 1 (or the network switches the UE to the base station 1), the base station 1 configures two cells (Cell1, Cell2) operating simultaneously for the UE1 according to the capability of the UE1, wherein the Cell1 provides NAS layer mobility information such as PLMN, global Cell identifier CGI, location area identifier TAC, and the like for the UE1, and is a primary Cell (Pcell) or a primary serving Cell of the UE1, and the UE1 only receives system messages and paging messages of the primary Cell. Cell1, Cell2 may be RRH cells, or cells passing through a repeater, or normal cells. The two cells are FDD, and the procedure is the same for TDD cells, and the description is not repeated.
Example one
In this embodiment, the Cell2 schedules itself, and the UE in the Cell2 broadcast sends the random access preamble at the time of reach-FreqOffset ═ 10 and reach-ConfigIndex ═ 3 (the random access preamble can be sent in the subframe 1 of any radio frame). Fig. 3 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention, and as shown in fig. 3, the method for accessing a secondary serving cell according to the embodiment of the present invention mainly includes the following steps:
step 301, the base station sends MAC CE to the UE, including a command to activate Cell2, and the UE activates Cell2 after receiving the command.
Step 302, the base station notifies the UE, or the UE learns that different TAs need to be used for Cell2 and Cell1 according to the bs pre-configuration information, and needs to perform a TA acquisition process on Cell2, and at the same time notifies the UE that a random access preamble can be initiated on subframe 5 of the next radio frame (here, subframe 5 is selected to be distinguished from subframe 1 in the system message broadcast, and may be any subframe other than subframe 1, and the radio frame may also be the current radio frame, and the base station determines the earliest possible transmission timing and notifies the UE). Here, the random access preamble transmission opportunity may be combined with the activation command to notify the UE.
Step 303, the UE performs the TA acquisition process on Cell2, selects a common preamble by itself, and sends the common preamble to the base station at a designated time through the PRACH of Cell 2.
Step 304, the base station receives the common preamble, calculates TA, generates a response message, and sends the response message to the UE on the DL-SCH of the Cell2, where the message includes TA and may also include uplink grant; this message is indicated by the RA-RNTI (or C-RNTI) on the PDCCH on Cell 2.
In step 305, after obtaining the TA, the UE considers that Cell2 is successfully accessed, and may send and receive data normally on Cell2, and automatically forbids sending a random access preamble on subframe 5.
In this embodiment, if the UE does not receive the response from the base station in the specified time, the UE automatically sends the random access preamble again in the specified subframe of the next radio frame, for example, subframe 5, and if the attempts are not successful after the specified number of times, the UE abandons the attempts.
Example two
In this embodiment, the Cell2 schedules itself. Fig. 4 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention, and as shown in fig. 4, the method for accessing a secondary serving cell according to the embodiment of the present invention mainly includes the following steps:
step 401, the base station sends MAC CE to the UE, including a command to activate Cell2, and the UE activates Cell2 after receiving the command;
step 402, the base station notifies the UE, or the UE learns that different TAs are needed for Cell2 and Cell1 according to the base station pre-configuration information, and needs to execute a process of acquiring the TA on Cell2, and notifies the UE, and the UE can send a random access preamble or uplink data at an authorized time in uplink authorization of Cell 2. Here, the uplink grant may be combined with the activation command to notify the UE.
Step 403, the UE performs a TA acquisition process on Cell2, selects a common preamble by itself, and sends the common preamble to the base station through the UL SCH of Cell2 at a specific time, at this time, the UE may also send an uplink data to the base station;
step 404, the base station receives the common preamble or uplink data, calculates TA, generates a response message, and sends the response message to the UE on the DL-SCH of Cell2, where the message includes TA and may also include uplink grant; this message is indicated by the RA-RNTI (or C-RNTI) on the PDCCH on Cell 2;
in step 405, after obtaining the TA, the UE considers that Cell2 is successfully accessed, and can normally transmit and receive data on Cell 2.
In this embodiment, if the UE does not receive the response from the base station at the specified time, the UE automatically gives up.
EXAMPLE III
In this embodiment, Cell2 is scheduled by Pcell, the timing for UE in Cell2 broadcast to send a random access preamble is prach-FreqOffset ═ 10, and prach-ConfigIndex ═ 3 (subframe 1 of any radio frame can send a random access preamble), fig. 5 is a flowchart of a method for assisting serving Cell access in the embodiment of the present invention, and as shown in fig. 5, the method for assisting serving Cell access in the embodiment of the present invention mainly includes the following steps:
step 501, the base station sends the MAC CE to the UE, including a command to activate Cell2, and the UE activates Cell2 after receiving the command;
in step 502, the base station notifies the UE, or the UE learns that different TAs need to be used for Cell2 and Cell1 according to the bs pre-configuration information, and needs to perform a TA acquisition process on Cell2, and at the same time notifies the UE that a random access preamble can be initiated on subframe 5 of the next radio frame (here, subframe 5 is selected to be distinguished from subframe 1 in the system message broadcast, and may be any subframe other than subframe 1, and the radio frame may also be the current radio frame, and the base station determines the earliest possible transmission timing and notifies the UE). Here, the random access preamble transmission opportunity may be combined with the activation command to notify the UE.
Step 503, the UE performs the TA acquisition process on Cell2, and selects a common preamble by itself, and sends the common preamble to the base station at a designated time through the PRACH of Cell 2.
Step 504, the base station receives the common preamble, calculates TA, generates a response message, and sends the response message to the UE on the DL-SCH of Cell2, where the message includes TA and may also include uplink grant; the message is indicated by RA-RNTI (or C-RNTI) on PDCCH related to Cell2 on Pcell;
in step 505, after obtaining the TA, the UE considers that Cell2 is successfully accessed, and may send and receive data normally on Cell2, and automatically forbids sending a random access preamble on subframe 5.
Example four
In this embodiment, the Cell1 schedules itself, and the UE in the Cell2 broadcast sends the random access preamble at the time of reach-FreqOffset ═ 10 and reach-ConfigIndex ═ 3 (the random access preamble can be sent in the subframe 1 of any radio frame). Fig. 6 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention, and as shown in fig. 6, the method for accessing a secondary serving cell according to the embodiment of the present invention mainly includes the following steps:
601, when uplink data arrive at the UE and the data volume is large, the Cell2 is in an out-of-step state and is deactivated, and the UE learns that the Cell2 and the Cell1 need to adopt different TAs according to the base station pre-configuration information and needs to acquire the TAs on the Cell 2;
step 602, the UE notifies the base station through the Pcell that the Cell2 needs to be activated, or that a process for acquiring TA needs to be executed on the Cell 2;
and the notification message contains the cell identification of the TA which needs to be activated or acquired.
Step 603, sending the MAC CE to the UE, including a command to activate Cell2, and activating Cell2 after receiving the command;
in step 604, the base station notifies the UE that a random access preamble can be initiated in a subframe 5 of a next radio frame (here, the subframe 5 is selected to be distinguished from subframe 1 in the system message broadcast, and may be any subframe except subframe 1, and the radio frame may also be a current radio frame, and the base station determines the earliest possible transmission opportunity and notifies the UE). Here, the random access preamble transmission opportunity may be combined with the activation command to notify the UE.
Step 605: the UE executes the process of acquiring TA on the Cell2, selects a common preamble by itself, and sends the common preamble to the base station at a designated time through the PRACH of the Cell2
Step 606: the base station receives the common preamble, calculates TA, generates a response message and sends the response message to the UE on DL-SCH of Cell2, wherein the message contains TA and also can contain uplink authorization; this message is indicated by the RA-RNTI (or C-RNTI) on the PDCCH on Cell 2;
step 607: after the UE obtains the TA, it considers that Cell2 is successfully accessed, and may send and receive data normally on Cell2, and automatically forbids sending random access preamble on subframe 5.
EXAMPLE five
In this embodiment, the Cell2 is scheduled by the Pcell, and the UE in the Cell2 broadcast sends the random access preamble at a time of prach-FreqOffset ═ 10 and a time of prach-ConfigIndex ═ 3 (subframe 1 of any radio frame can send the random access preamble). Fig. 7 is a flowchart of a method for accessing a secondary serving cell according to an embodiment of the present invention, and as shown in fig. 7, the method for accessing a secondary serving cell according to the embodiment of the present invention mainly includes the following steps:
step 701, when downlink data arrive at the UE and the data volume is large, the Cell2 is in an out-of-step state and is deactivated, the base station notifies the UE that the Cell2 and the Cell1 need to adopt different TAs, and a TA acquisition process needs to be executed on the Cell2, and the UE activates the Cell2 by itself;
in step 702, the base station notifies the UE that it can initiate random access preamble on subframe n of the current radio frame or the next radio frame (subframe n is a subframe that can normally send random access preamble, in this embodiment, subframe 1 is followed by 3 subframes, i.e., subframe 4) (here, subframe 4 is followed by 3 subframes after the normal subframe is selected to be distinguished from subframe 1 in the system message broadcast, which may be any subframe except subframe 1, and the radio frame may also be the current radio frame, and the base station determines the earliest possible sending opportunity and notifies the UE). Here, the random access preamble transmission opportunity may be combined with the activation command to notify the UE.
Step 703, the UE performs the TA acquisition process on Cell2, selects a common preamble, and sends the common preamble to the base station at a designated time via PRACH of Cell2
Step 704, the base station receives the common preamble, calculates TA, generates a response message, and sends the response message to the UE on the DL-SCH of Cell2, where the message includes TA and may also include uplink grant; the message is indicated by RA-RNTI (or C-RNTI) on PDCCH related to Cell2 on Pcell;
step 705, after obtaining the TA, the UE considers that Cell2 is successfully accessed, may receive downlink data on the DL-SCH in Cell2 and perform normal feedback, and automatically prohibits random access preamble transmission on subframe 4.
The invention also discloses a system for accessing the auxiliary service cell, which comprises the UE and the network side, wherein,
the UE is used for sending a random access preamble or uplink data to the network side through the auxiliary serving cell at the uplink authorization opportunity notified by the network side; and obtaining the TA fed back by the network side, and transmitting and receiving data in the auxiliary service cell;
the network side is used for calculating time adjustment TA according to the received random access preamble or uplink data and feeding back the TA to the UE; and notifying the UE of the uplink grant opportunity.
It should be understood by those skilled in the art that the system for assisting serving cell access of the present invention does not improve the existing communication network structure, and only improves the functions and interaction modes of part of network elements, and the following describes the improved parts in detail.
In the system for accessing the secondary serving cell, the uplink grant time is the earliest random access preamble or uplink data transmission time determined by the network side for the UE.
In the system for accessing the auxiliary service cell, the uplink authorization opportunity is a subframe behind a first subframe in a current frame or a next frame.
In the system for accessing the secondary serving cell of the present invention, the network side is further configured to send a notification of the uplink grant opportunity and a notification of an activation command for the secondary serving cell to the UE together; or sending a notification of the uplink grant occasion to the UE after the notification of the activation command of the secondary serving cell
In the system for accessing the auxiliary serving cell, the UE is further used for determining that the auxiliary serving cell and the main serving cell need to adopt different TAs;
or, the network side is further configured to notify the UE that the secondary serving cell and the primary serving cell need to use different TAs.
The network element at the network side mainly refers to a base station.
Fig. 8 is a schematic structural diagram of a network element on a network side according to an embodiment of the present invention, and as shown in fig. 8, the network element on the network side according to the embodiment of the present invention includes a determining unit 80, a receiving unit 81, a calculating unit 82, and a sending unit 83; wherein,
a determining unit 80, configured to determine, for the UE, an occasion for sending uplink data or a random access preamble;
a receiving unit 81, configured to receive a random access preamble or uplink data sent by a UE;
a calculation unit 82 for calculating TA;
a sending unit 83, configured to send the TA to the UE; and sending the uplink data or random access preamble sending time to the UE.
The determining unit 80 is further configured to determine an earliest random access preamble or uplink data transmission timing for the UE; the uplink grant time is a subframe which meets the time condition of sending uplink data or random access preamble in the current frame or the next frame.
The network element at the network side mainly refers to a base station.
It should be understood by those skilled in the art that the functions implemented by the processing units of the network-side network element shown in fig. 8 can be understood by referring to the related description of the foregoing method and system for access control. The functions may be implemented by a program running on a processor or by specific logic circuits.
Fig. 9 is a schematic diagram of a structure of a UE according to an embodiment of the present invention, and as shown in fig. 9, the UE according to an embodiment of the present invention includes a sending unit 90 and an access unit 91, wherein,
a sending unit 90, configured to send a random access preamble or uplink data to a network side through an auxiliary serving cell at an uplink data or random access preamble sending time notified by the network side;
the access unit 91 is configured to complete access to the secondary serving cell after receiving the TA sent by the network side.
The network element at the network side mainly refers to a base station.
It should be understood by those skilled in the art that the functions implemented by the processing units of the user equipment shown in fig. 9 can be understood by referring to the related description of the method and system for access control. The functions may be implemented by a program running on a processor or by specific logic circuits.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.