WO2013016988A1

WO2013016988A1 - Method and system for non-contention based random access, network-side network element, and user equipment

Info

Publication number: WO2013016988A1
Application number: PCT/CN2012/077380
Authority: WO
Inventors: 陈中明
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-08-01
Filing date: 2012-06-21
Publication date: 2013-02-07
Also published as: CN102917468A

Abstract

Disclosed is a method for non-contention based random access, comprising: a network side transmitting to a user equipment (UE) a media access control control element (MAC CE), where the MAC CE is configured with random access timing information of a cell or uplink grant (UL grant) information thereof; the UE transmitting on the cell a random access preamble on the basis of the random access timing, or transmitting on the cell the random access preamble or uplink data at a timing instructed by the UL grant; the network side calculating a time adjustment (TA) on the basis of the random access preamble or uplink data received, and feeding back to the UE, the UE successfully accessing the cell, and is thus allowed to perform normal data transmission and reception. Also disclosed are a system, network side network element, and user equipment for non-contention based random access. By implementing access to an auxiliary service cell via a non-contention based means, the present invention reduces greatly the time for accessing the cell, thus satisfying the requirement of the UE of receiving and transmitting expeditiously large amount of data.

Description

Method and system for non-conflicting random access, network side network element, user equipment

The present invention relates to a secondary serving cell access technology, and in particular, to a method and system for non-conflicting random access, a network side network element, and a user equipment. Background technique

In a wireless cellular communication system, a random access procedure (UE) for an idle state (RRC_IDLE) UE (or user equipment (UE)) initial access network, or a connection state (RRC_CONNECTED) UE Uplink synchronization with the network and acquisition of resource allocation for subsequent data communication.

In the evolved Evolved Universal Terrestrial Radio Access Network (E-UTRAN) of the 3GPP (Third Generation Partnership Project) Long Term Evolution (LTE), the following six The event may trigger the random access procedure of the UE: (1) idle state initial access; (2) RRC Connection Re-establishment procedure; (3) handover (HO, Handover); (4) RRC connection status downlink data arrival requires a random access procedure, for example, when the uplink synchronization status is "non-synchronized"; (5) RRC connection status uplink data arrival requires a random access procedure, for example, when the uplink synchronization status is "unsynchronized" or There is no physical uplink control channel (PUCCH, Physical Uplink Control Channel) resource transmission scheduling request (SR, Schedule Request); (6) RRC connection status requires random access procedure for positioning purposes, for example, UE positioning requires timing advance (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 physical downlink control channel signaling (PDCCH order) or a media access control layer (MAC) of the UE, optionally, PDCCH order or 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-collision-based manner; otherwise, the UE needs to select a random access preamble, and the random access procedure is a conflict-based manner. The UE selecting the random access resource includes selecting a random access preamble and a time-frequency domain resource of a Physical Random Access Channel (PRACH). For non-conflicting random access procedures, there is no conflict resolution process. Figure 1 is a schematic diagram of an existing random access procedure. As shown in Figure 1, the contention based random access procedure mainly includes the following steps:

Step 101: The UE sends a random access preamble through a random access channel (RACH, Random Access CHannel). The timing of the UE sending the random access preamble is configured in a system message broadcast, and the main configuration is frequency. Domain and time domain resources, where the frequency domain is configured with rach-FreqOffset (frequency offset of PRACH), and the time domain is configured with prach-Configlndex (which subframes on PRACH can send random access preambles).

Step 102: A medium access control layer (MAC) of the base station (eNB) generates a random access response message and sends the message to the UE on a downlink shared channel (DL-SCH, Downlink-Shared Channel); the random access response The message includes at least a random access preamble ID (RAPID), a time adjustment (TA, Time Alignment) information, an initial uplink grant (UL Grant, Uplink Grant), and a temporary cell-wireless network temporary identifier (Temporary C- RNTI); the random access response message is indicated by a random access-Radio Network Temporary Identifier (RA-RNTI) on the physical downlink control channel (PDCCH, Phisical Downlink Control CHannel); The uplink grant indicates the frequency domain information of the uplink data sent by the UE and the required configuration information, such as power control. Step 103: The UE sends a first scheduled transmission (UL-SCH, Uplink-Shared Channel) message, where the content of the scheduled transmission message includes at least a cell-wireless network temporary identifier (C- RNTI), a Media Control Element (MAC Control Element) or a Common Control Logical Channel Service Data Unit (CCCH SDU) including a Contention Resolution Identity; the transmission of the scheduled transmission message supports a hybrid automatic repeat request ( HARQ, Hybrid Automatic Retransmission reQuest).

Step 104: The base station sends a contention resolution message on the DL-SCH. The conflict resolution message is indicated by a C-RNTI or a temporary C-RNTI on the PDCCH, and may include a conflict resolution identifier. The message is sent to support HARQ.

The above steps 103 and 104 are used to resolve the conflict. Among the six events that trigger the random access procedure of the UE, (4) the RRC connection state downlink data arrival requires a random access procedure, and (5) the RRC connection state uplink data arrival requires a random access procedure, which triggers the Scdl execution. The random access procedure, but does not preclude other events from triggering the Scdl to perform a random access procedure, such as when the Scdl is activated, triggering the execution of the random access procedure.

In order to provide mobile users with higher data rates, the Long Term Evolution (LTE-A) system proposes Carrier Aggregation (CA), which aims to provide greater bandwidth for UEs with corresponding capabilities. Data transmission increases the peak rate of the UE. In the LTE system, the maximum downlink transmission bandwidth supported by the system is 20 MHz. Carrier aggregation is to aggregate two or more component carriers (CC, Component Carriers) to support a transmission bandwidth greater than 20 MHz and a maximum of 100 MHz. The initial stage UL CC The total number of configurations is less than or equal to the total configuration of the DL CC. An LTE-A UE with carrier aggregation capability can transmit and receive data on multiple component carriers at the same time. The UEs referred to below refer to such UEs unless otherwise specified. In the LTE-A system, after the UE enters the connected state, it can communicate with the source base station through multiple component carriers (such as CC1 and CC2) at the same time. The base station will specify one for the UE through explicit configuration or according to the protocol. The primary component carrier (PCC, Primary Component Carrier), the other component carrier is called the secondary component carrier (SCC), and the serving cell on the PCC is called the primary serving cell (Pcdl, Primary Cell), on the SCC. cell service called secondary serving cell (Scdl, secondary cell) ₀ is a secondary serving cell after the UE enters the connected state of the base station configuration. In general, a serving cell has symmetric uplink and downlink (Scdl can only configure downlink). It is clearly indicated in the system information block SIB2 that in order to avoid interference of the control channel, the concept of cross-carrier scheduling is introduced, that is, when If the PDCCH interference of a certain Scdl is severe, the PDCCH of the Scdl is not enabled, but the PDSCH of the Scdl is scheduled by another serving cell, where another serving cell can be configured through RRC signaling. The base station only allocates one C-RNTI to the UE, that is, the C-RNTI of each serving cell is the same.

According to RdlO, in the initial stage of carrier aggregation, the number of Scdl is less than one, and the scenario is limited to that if the uplink RRH and the repeater are not supported, only one TA exists, and the UE only needs to initiate uplink synchronization in the Pcdl. It will not be launched on Scdl. In the subsequent stage, due to the increase in the amount of Scdl data, the number of Scdl will increase to four, and the scene will be relaxed. For example, the uplink RRH and repeater are supported. At this time, one TA will not solve the problem, so multiple TAs will be introduced. At this time, the uplink synchronization is also initiated on the Scdl, and the random access process is performed after the Scdl is activated. The Scdl must perform normal uplink data transmission and reception after the uplink synchronization is completed. If the non-conflicting random access procedure is performed on the Scdl, the time is relatively short. If the conflicting random access procedure is performed, the time will be longer. In order to improve the user experience, it is necessary to select a non-contention random access procedure to perform data transmission and reception as soon as possible for the random access procedure on the Scdl. If the dedicated preamble resources are missing or insufficient, the Scdl access is inevitably increased. Therefore, it is necessary to shorten the random access process of Scdl and speed up user access. Summary of the invention

In view of this, the main purpose of the present invention is to provide a non-conflicting random access method and system, a network side network element, and a user equipment, which can implement fast access of the Scdl. In order to achieve the above object, the technical solution of the present invention is achieved as follows:

A method for non-conflicting random access, comprising:

Receiving, by the UE, a MAC CE sent by the network side, where the MAC CE is configured with a random access occasion information or an uplink grant UL grant information;

Transmitting, by the UE, a random access preamble on the cell according to the random access occasion, or sending random access preamble or uplink data on the cell at a timing indicated by the UL grant; and receiving the The time adjustment TA of the network side feedback accesses the cell.

Preferably, the TA is fed back by the network side according to the received random access preamble or uplink data calculation.

Preferably, the random access occasion information or the UL grant information of the cell in which the MAC CE is set is:

The MAC CE is configured with a cell that carries the identification information of the cell, and a cell that carries the random access timing information or the UL grant information, where

The bit carrying the identification information of the cell has a fixed correspondence with the bit carrying the random access occasion information or the UL grant information;

Alternatively, the random access opportunity information or the UL grant information in the cell sequentially corresponds to the valid identifier of the cell.

Preferably, the valid identifier of the cell is:

The bit indicating the cell to be activated is "1", and the identifier of the cell is valid.

The MAC CE is configured with a cell that carries random access opportunity information or UL grant information, and is used to indicate the current cell.

Preferably, the random access opportunity is a subframe in a radio frame.

Preferably, the random access opportunity is the random access opportunity in the current frame or the next frame The specified subframe.

Preferably, the network side is a base station.

A method for non-conflicting random access, comprising:

The network side sends a MAC CE to the UE, where the MAC CE is provided with the random access opportunity information of the cell or the uplink grant UL grant information;

The network side sends a random access preamble or uplink on the cell according to the timing of the UL grant indication according to the random access preamble sent by the UE on the cell at a random access occasion. Data, calculating the TA and feeding back to the UE to enable the UE to access the cell.

Preferably, the random access opportunity is a subframe in a radio frame;

Or the random access occasion is a subframe specified by the random access occasion in the current frame or the next frame.

A non-conflicting random access system, including a UE and a network side, where a network side, configured to send a MAC CE to the UE, where the MAC CE is configured with random access timing information or UL grant information of the cell; and, according to the received random access preamble or uplink data, a time adjustment TA, And feeding back to the UE, activating the cell;

a UE, configured to send a random access preamble on the cell according to the random access occasion, or send a random access preamble or uplink data on the cell at a timing indicated by the UL grant; The TA fed back by the network side accesses the cell.

Preferably, the network side is further configured to calculate a feedback TA according to the received random access preamble or uplink data.

Preferably, the MAC CE is provided with a cell carrying the identity information of the cell and a cell carrying the random access opportunity information or the UL grant information, where

The bit carrying the identification information of the cell has a fixed correspondence with the bit carrying the random access occasion information or the UL grant information; or the random access timing information or the UL in the cell The grant information sequentially corresponds to the valid identifier of the cell;

Alternatively, the MAC CE is configured with a cell that carries random access opportunity information or UL grant information, and is used to indicate the set cell.

Preferably, the random access occasion or the timing indicated by the UL grant is a subframe in a frame. Preferably, the random access occasion or the timing indicated by the UL grant is a subframe after the first subframe in the current frame or the next frame.

A network side network element, including a receiving unit, a calculating unit, and a sending unit, where the receiving unit is configured to receive random access preamble or uplink data sent by the UE;

a calculation unit, configured to calculate a TA;

a sending unit, configured to send the TA to the UE, and send a MAC CE to the UE, where the MAC CE is configured with random access occasion information or UL grant information of the cell.

A user equipment, including a sending unit and an access unit, where a sending unit, configured to send a random access preamble on the cell at a random access occasion of the cell, or send a random access preamble or uplink data on the cell at a timing indicated by the UL grant;

The access unit is configured to access the cell after receiving the TA sent by the network side.

In the present invention, the media access control control unit (MAC CE) is extended, and the random access timing information or the UL grant information indicating the cell is set, so that the base station notifies the random cell of the cell through the MAC CE. An access opportunity or a UL grant, the UE sends a random access preamble on the cell according to the random access occasion, or sends a random access preamble or uplink data on the cell at the timing indicated by the UL grant; The time adjustment TA is calculated according to the received random access preamble or uplink data, and is fed back to the UE. After receiving the UE, the UE successfully accesses the cell, and can perform normal data transmission and reception in the cell. The invention can realize the access of the secondary serving cell through the non-contention mode, greatly shortens the time of the cell access, and satisfies the requirement that the UE can quickly send and receive a large amount of data. DRAWINGS

FIG. 1 is a schematic diagram of an existing random access process;

2 is a schematic diagram of an existing MAC CE;

3 is a schematic diagram of a MAC CE of the present invention;

4 is a schematic diagram of a MAC CE of the present invention;

Figure 5 is a schematic diagram of a MAC CE of the present invention;

6 is a schematic diagram of a MAC CE according to Embodiment 1 of the present invention;

7 is a schematic diagram of a MAC CE according to Embodiment 2 of the present invention;

8a is a schematic diagram of a MAC CE according to Embodiment 3 of the present invention;

8b is a schematic diagram of a MAC CE according to Embodiment 3 of the present invention;

9 is a schematic diagram of a MAC CE according to Embodiment 4 of the present invention;

10 is a schematic diagram of a MAC CE according to Embodiment 5 of the present invention; FIG. 11 is a schematic structural diagram of a network side network element according to an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of a user equipment according to an embodiment of the present invention. detailed description

The basic idea of the present invention is to set a random access timing information or UL grant information indicating a cell to be transmitted by extending a Media Access Control Control Element (MAC CE), so that the base station notifies by MAC CE. a random access occasion or a UL grant of the cell, where the UE sends a random access preamble or uplink data according to the timing indicated by the random access occasion or the UL grant; the base station calculates according to the received random access preamble or uplink data. The time adjustment TA is performed and fed back to the UE. After receiving the UE, the UE considers that the access is successful, and can perform normal data transmission and reception in the cell.

The present invention will be further described in detail below with reference to the accompanying drawings.

In multi-carrier systems, the introduction of Scdl is to increase the traffic rate. In addition, when the carrier aggregation is just introduced, an activation deactivation mechanism is also introduced for Scdl, and the deactivation mechanism is activated in order to make the Scell be utilized as soon as possible. The non-conflicting random access procedure is implemented by the network side UE for allocating a dedicated preamble. If the dedicated preamble resource is missing, only the conflicting random access procedure can be used, or the available dedicated preamble resources are waiting for the two. The approach will bring a certain delay, which is obviously contrary to the fundamental purpose of Scdl activation. The present invention is directed to the above-mentioned deficiencies. The main technical solution is that the network side provides a dedicated manner for transmitting a random access preamble opportunity to the UE, and the UE sends a random access preamble to perform a non-conflicting random access procedure at a specified timing, thereby effectively replenishing the Scdl. When performing random access, the problem that fast access is required when the dedicated preamble is missing.

2 is a schematic diagram of an existing MAC CE. As shown in FIG. 2, in the current Scell activation command, Ci indicates a Scdl identifier that needs to be activated or deactivated. When Ci is 1, it indicates that the Scell indicated by Ci needs to be activated. When Ci is 0, Indicates that ScelL needs to be deactivated for Ci indication

In order to notify the UE of the random access occasion or UL grant of the cell, the present invention is directed to the MAC. The CE is extended. Specifically, the MAC CE is configured with a cell that carries the identity information of the cell, or a cell that carries the random access opportunity information or the UL grant information, where

If the MAC CE includes both the cell identity information and the random access preamble or the UL grant information, the bit carrying the identity information of the cell and the bit carrying the random access opportunity information or the UL grant information Have a fixed correspondence;

If the MAC CE only includes the random access preamble or UL grant information, the random access preamble or UL grant information only corresponds to the cell that receives the MAC CE.

3 is a schematic diagram of a MAC CE according to the present invention. As shown in FIG. 3, Subframe1 to Subframe7 respectively indicate that a random access preamble is sent when a Scell with cell identifiers 1 to 7 performs random access, and Subframe1 to Subframe7 and a cell identifier are 1 to 7. The Scell has a corresponding relationship. Certainly, as a variant, the cell carrying the random access timing information may be set to a variable bit manner. When two cells are required to be activated, only the random access timing information of the two cells is carried, and the two random numbers are randomly selected. The access timing information may be sequentially corresponding to the two cells of the cell to be activated.

4 is a schematic diagram of a MAC CE according to the present invention. As shown in FIG. 4, UL grant1 to UL grant 7 respectively indicate uplink grants for transmitting random access preamble or uplink data when a cell with cell identifiers 1 to 7 performs random access, UL. The grant1 to UL grant 7 has a corresponding relationship with the Scell whose cell identifiers are 1 to 7. As a matter of course, as a variant, the cell carrying the uplink grant may be set to a bit-variable manner. When the two cells need to be activated, the UL grant information of only two cells may be carried. The two UL grants may be used. The information and the two cells of the above-mentioned cell to be activated may be sequentially applied.

FIG. 5 is a schematic diagram of a MAC CE according to the present invention. As shown in FIG. 5, only one cell carrying random access timing information or uplink grant information is added to the MAC CE, where the Subframe indicates that the designated Scell is randomly selected and sent randomly. When entering the predecessor, ULgrant means to specify Scell The uplink grant of the random access preamble is sent when random access is performed.

In the above Figs. 2 to 5, "R" indicates a reserved bit. Seven cell indication bits are set, which is enough to identify the number of cells corresponding to the maximum carrier supported by the UE.

The essence of the technical solution of the present invention will be further clarified by specific examples below.

In the LTE-A system, the base station 1 is a base station having carrier aggregation capability. Base station 1 is under the jurisdiction

Three cells, Celll, Cdl2, and Cell3. Some or all of these three cells may provide carrier aggregation capabilities to the user equipment to extend the bandwidth of the transmission. The user equipment UE1 accesses the network through the base station 1 (or the network switches the UE to the base station 1), and the base station 1 configures three simultaneously working cells (Cell, Cdl2, and Cell3) according to the capability of the UE1, where the Celll provides the UE1. The NAS layer mobility information, such as the PLMN, the global cell identifier CGI, and the location area identifier TAC, is the primary cell (Pcdl, Primary Cell) of the UE1, or the primary serving cell, and the UE1 only receives the system message and the paging message of the primary cell. Cdll and Cdl2 can be RRH cells, or pass repeater, or ordinary cells. The cell IDs of Celll, Cdl2, and Cdl3 are 0, 1, and 2, respectively. These three cells are FDD. For the TDD cell, the process is the same and will not be repeated.

Embodiment 1

In this example, Cdl3 is itself scheduling itself. The timing at which the UE in the Cdl3 broadcast transmits the random access preamble is prach-FreqOffset=10, prach-ConfigIndex=3 (subframe 1 of any wireless frame can transmit a random access preamble).

Step 1: The base station sends a MAC CE to the UE. 6 is a schematic diagram of a MAC CE according to Embodiment 1 of the present invention. As shown in FIG. 6, in this example, a MAC CE includes a command to activate Cdl3 and a timing to allow a random access preamble to be transmitted, such as subframe 5, after receiving a command by the UE. Activating Cdl3 and transmitting a common random access preamble in subframe 5 of the most recent radio frame;

Step 2: The base station receives the public random access preamble, calculates a TA, and generates a response message, which is sent to the UE in the DL-SCH of the Cell3, where the message includes the TA; the message passes through the Cdl3. The RA-RNTI (or C-RNTI) on the PDCCH is indicated;

Step 3: After obtaining the TA, the UE considers that the Cdl3 access is successful, and can normally send and receive data on the Cdl3, and automatically prohibits sending the random access preamble on the subframe 5.

Embodiment 2

In this example, Cdl2 and Cell3 are themselves scheduling themselves. The timing of the UE transmitting the random access preamble in the Cdl2 broadcast is prach-FreqOffset=10, prach-ConfigIndex=5 (subframe 7 of any radio frame can be sent. The random access preamble), the timing of the UE in the Cell3 broadcast to send the random access preamble is prach-FreqOffset=10, prach-ConfigIndex=3 (subframe 1 of any radio frame can send a random access preamble).

Step 1: The base station sends a MAC CE to the UE. FIG. 7 is a schematic diagram of a MAC CE according to Embodiment 2 of the present invention. As shown in FIG. 7, in this example, the MAC CE includes a command to activate Cell2 and Cdl3, and includes a Cdl2 permission to send. The timing of random access preamble, such as subframe 5 and Cdl3, is allowed to transmit the random access preamble timing, such as subframe 3. After receiving the MAC CE, the UE activates Cdl2 and Cdl3, and passes through subframe 3 of the latest radio frame. Cell3 transmits a common random access preamble, and transmits a common random access preamble through Cdl2 on subframe 5 of the latest radio frame;

Step 2: The base station receives the common random access preamble on the Cdl2, calculates the TA, and generates a response message, which is sent to the UE in the DL-SCH of the Cdl2, where the message includes the TA; the message passes the RA-RNTI on the PDCCH on the Cdl2 ( Or C-RNTI) to indicate;

Step 3: The base station receives the common random access preamble on the Cdl3, calculates the TA, and generates a response message, which is sent to the UE in the DL-SCH of the Cdl3, where the message includes the TA; the message passes the RA-RNTI on the PDCCH on the Cdl3 ( Or C-RNTI) to indicate;

Step 4: After obtaining the TA, the UE considers that Cell 2 and Cell 3 are successfully accessed, can normally send and receive data on Cdl2 and Cdl3, and automatically prohibits sending random access on subframe 3 and subframe 5. Embodiment 3

In this example, Cdl2 and Cdl3 are themselves scheduling themselves.

Step 1: The base station sends a MAC CE to the UE. FIG. 8a is a schematic diagram of the MAC CE according to the third embodiment of the present invention. As shown in FIG. 8a, in this example, the MAC CE includes a command to activate Cell2, and includes the uplink authorization of the UE in Cell2. And the uplink grant on Cell3, the UE may send random access preamble or uplink data at the time of uplink grant. After receiving the command, the UE activates Cdl2 and Cell3 respectively, and sends the common random access preamble or uplink data in the uplink authorized subframe respectively. Step 2: The base station receives the public random access preamble or uplink data on Cdl2, and calculates The TA, the generated response message is sent to the UE in the DL-SCH of the Cdl2, where the message includes the TA; the message is indicated by the RA-RNTI (or C-RNTI) on the PDCCH on the Cell2;

Step 3: The base station receives the common random access preamble or uplink data on the Cell3, calculates the TA, and generates a response message, which is sent to the UE in the DL-SCH of the Cdl3, where the message includes the TA; the message passes the RA on the PDCCH on the Cell3. - RNTI (or C-RNTI) for indication;

Step 4: After obtaining the TA, the UE considers that Cell2 and Cell3 are successfully accessed, and can normally send and receive data on Cdl2 and Cdl3.

In this embodiment, if only one cell is activated, such as only Cdl3 is activated, then only one uplink grant may be included. FIG. 8b is a schematic diagram of a MAC CE according to Embodiment 3 of the present invention. As shown in FIG. 8b, in this example, a MAC CE structure is shown in FIG. 8b, and the uplink authorization is for Cell3.

Embodiment 4

In this example, Cell2 is scheduled by Pcell. The timing at which the UE in the Cell2 broadcast transmits the random access preamble is prach-FreqOffset=10, prach-ConfigIndex=5 (subframe 7 of any radio frame can send a random access preamble).

Step 1: The UE has uplink data arrives, and the amount of data is relatively large. At this time, Cdl2 is in an out-of-synchronization state, and has been deactivated. The UE learns that Cdl2 and Cdll need to adopt different TAs according to the pre-configuration information of the base station, and needs to acquire the TA on Cdl2. Step 2: The UE notifies the base station through the Pcdl, needs to activate the Cdl2, or needs to perform the process of acquiring the TA on the Cdl2; and may include the cell identifier that needs to be activated or needs to acquire the TA.

Step 3: The base station sends a MAC CE to the UE, and includes a command to activate the Cell2, and the UE activates the Cell2 after receiving the command;

Step 4: The base station sends the MAC CE to the UE through the Cdl2. FIG. 9 is a schematic diagram of the MAC CE according to the fourth embodiment of the present invention. As shown in FIG. 9, in this example, the timing of allowing the random access preamble to be sent on the Cdl2 in the MAC CE is as follows. Frame 5, and transmits a common random access preamble in subframe 5 of the most recent radio frame.

Step 5: The base station receives the common random access preamble, calculates the TA, and generates a response message, which is sent to the UE in the DL-SCH of the Cdl2, where the message includes the TA, and may also include an uplink grant; the message passes the Cell2 related PDCCH on the Pcdl. The RA-RNTI (or C-RNTI) on the indication is given;

Step 6, after obtaining the TA, the UE considers that the Cdl2 access is successful, and can normally send and receive data on the Cdl2, and automatically prohibits sending the random access preamble on the subframe 5.

Embodiment 5

In this example, Cell2 is scheduled by Pcdl.

Step 1: The UE has downlink data arriving, and the amount of data is relatively large. At this time, Cdl2 is in an out-of-synchronization state, and has been deactivated. The base station notifies the UE that the cell Cdl2 and the Cdll need to adopt different TAs, and needs to perform the process of acquiring the TA on the Cell2. When the UE activates the Cell2 by itself;

Step 2: The base station sends a MAC CE to the UE. FIG. 10 is a schematic diagram of a MAC CE according to Embodiment 5 of the present invention. As shown in FIG. 10, in this example, the MAC CE notifies the UE of the uplink grant on Cdl2, and the UE may be authorized in the uplink. The timing sends random access preamble or uplink data. After receiving the command, the UE activates Cdl2 and sends public random access preamble or uplink data in the uplink authorized subframe.

Step 3: The base station receives the public random access preamble or uplink data on Cdl2, and calculates the TA. Generating a response message to the UE on the DL-SCH related to the Cdl2 on the Pcell, where the message includes the TA; the message is indicated by the RA-RNTI (or C-RNTI) on the PDCCH on the Cell2;

Step 4: After obtaining the TA, the UE considers that the Cdl2 access is successful, and may be on the Cdl2.

The downlink data is received on the DL-SCH and normal feedback is performed.

The present invention also describes a non-conflicting random access system, including a UE and a network side, where the network side is configured to send a MAC CE to the UE, where the MAC CE is set with a random access occasion of the cell to be activated. Information or UL grant information; and, calculating a time adjustment TA according to the received random access preamble or uplink data, and feeding back to the UE, activating the to-be-activated cell;

And the UE is configured to send a random access preamble on the to-be-activated cell according to the random access occasion, or send a random access preamble or uplink data on the to-be-activated cell at the timing indicated by the UL grant.

It should be understood by those skilled in the art that the non-conflicting random access system of the present invention does not improve the structure of the existing communication network, and only improves the functions and interaction modes of some network elements, and will be improved below. Partially detailed description.

The MAC CE is configured with a cell that carries the identification information of the cell to be activated, and a cell that carries the random access opportunity information or the UL grant information, where

The bit that carries the identification information of the to-be-activated cell has a fixed correspondence with the bit that carries the random access occasion information or the UL grant information; or, the random access opportunity information or the location in the cell The UL grant information sequentially corresponds to the valid identifier of the to-be-activated cell;

The timing of the random access occasion or the UL grant indication is a subframe in a frame. The timing of the random access occasion or the UL grant indication is a subframe after the first subframe in the current frame or the next frame.

FIG. 11 is a schematic structural diagram of a network side network element according to an embodiment of the present invention. As shown in FIG. 11, the network side network element of the present invention includes a receiving unit 110, a calculating unit 111, and a sending unit 112.

The receiving unit 110 is configured to receive the random access preamble or uplink data sent by the UE, and the calculating unit 111 is configured to calculate the TA;

The sending unit 112 is configured to send the TA to the UE, and send a MAC CE to the UE. The MAC CE is configured with random access timing information or UL grant information of the cell.

The above network side network element mainly refers to a base station.

It should be understood in the art that the implementation functions of the processing units of the network side network element shown in FIG. 11 can be understood by referring to the related description of the foregoing non-conflicting random access method and system. Its function can be realized by a program running on the processor, or by a specific logic circuit.

FIG. 12 is a schematic structural diagram of a user equipment according to an embodiment of the present invention. As shown in FIG. 12, the user equipment of the present invention includes a sending unit 120 and an access unit 121, where

The sending unit 120 is configured to send a random access preamble on the cell at a random access occasion of the cell, or send random access preamble or uplink data on the cell at the timing indicated by the UL grant;

The access unit 121 is configured to access the cell after receiving the TA sent by the network side. The above network side network element mainly refers to a base station.

It should be understood in the art that the implementation functions of the processing units of the user equipment shown in FIG. 12 can be understood by referring to the related description of the foregoing non-conflicting random access method and system. Its function can be realized by a program running on the processor, or by a specific logic circuit.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Range of protection.

Industrial applicability

In the present invention, by extending the MAC CE, setting the random access timing information or the UL grant information indicating the cell, so that the base station notifies the random access occasion or the UL grant of the cell through the MAC CE, and the UE according to the random access The timing is to send a random access preamble on the cell, or send random access preamble or uplink data on the cell at the timing indicated by the UL grant; the base station calculates time adjustment according to the received random access preamble or uplink data. The TA is fed back to the UE. After receiving the UE, the UE successfully accesses the cell, and can perform normal data transmission and reception in the cell.

Claims

Claim

A method for non-conflicting random access, the method comprising:

The user equipment UE receives the media access control control unit MAC CE sent by the network side, where the MAC CE is provided with random access timing information or uplink grant UL grant information of the cell;

2. The method according to claim 1, wherein the TA is fed back by the network side according to the received random access preamble or uplink data calculation.

The method according to claim 1, wherein the random access occasion information or the UL grant information of the cell in which the MAC CE is set is:

The method according to claim 3, wherein the valid identifier of the cell is: indicating that the bit of the to-be-activated cell is "1", and the identifier of the cell is valid.

The method according to any one of claims 1 to 5, wherein the random access time The machine is a subframe in a radio frame.

7. The method according to claim 6, wherein the random access occasion is a subframe specified by the random access occasion in a current frame or a next frame.

8. The method according to claim 6, wherein the network side is a base station.

A method for non-conflicting random access, wherein the method includes:

10. The method according to claim 9, wherein the random access occasion information or the UL grant information of the cell in which the MAC CE is set is:

The method according to claim 9, wherein the random access occasion information or the UL grant information of the cell in which the MAC CE is set is:

The method according to any one of claims 9 to 11, wherein the random access occasion is a subframe in a radio frame; Or the random access occasion is a subframe specified by the random access occasion in the current frame or the next frame.

A non-conflicting random access system, including a UE and a network side, where: a network side, configured to send a MAC CE to a UE; where the MAC CE is configured with a random access occasion information or a UL grant of the cell And: calculating a time adjustment TA according to the received random access preamble or uplink data, and feeding back to the UE, and activating the cell;

14. The system of claim 13 wherein

The network side is further configured to calculate a feedback TA according to the received random access preamble or uplink data.

15. The system of claim 13 wherein

The system according to any one of claims 13 to 15, wherein the timing of the random access occasion or the UL grant indication is a subframe in a frame.

The method according to claim 16, wherein the random access occasion or the timing indicated by the UL grant is a subframe after the first subframe in the current frame or the next frame.

18. A network side network element, comprising: a receiving unit, a calculating unit, and a sending unit; wherein a receiving unit, configured to receive random access preamble or uplink data sent by the UE, and a calculating unit, configured to calculate a TA;

19. A user equipment, including a sending unit and an access unit, where

a sending unit, configured to send a random access preamble on the cell at a random access occasion of the cell, or send a random access preamble or uplink data on the cell at a timing indicated by the UL grant;