WO2009100660A1 - A random access control method, system and device - Google Patents

Abstract

A random access control method, system and device are provided in the embodiments of the present invention, the method involves: the indication message sent from the base station is received, the information for transforming the access transmission type is carried in the indication message; the access transmission type is changed according to the information for transforming the access transmission type to perform the uplink access. In the present invention, the base station controls the uplink access transmission type of the user equipment according to the load situation, and transforms the access transmission type that occupies more resources into the access transmission type that occupies few resources, the uplink total load of the current cell in the base station or the corresponding access transmission type load is reduced, so as to reduce the congestion probability occurred in the transmission path of the user equipment.

Description

 The present invention claims to be submitted to the Chinese Patent Office on February 5, 2008, and the application number is 200810074277.3, and the invention name is "a random access control method, system and device" The priority of the Chinese Patent Application, the entire contents of which is incorporated herein by reference. Technical field

 The present invention relates to the field of communications technologies, and in particular, to a random access control method, system, and device. Background technique

 3GPP (3rd Generation Partnership Project) WCDMA (Wideband Code Division Multiple Access) R8 version introduces Enhanced RACH (Random Access Channel), which is enhanced in 3GPP WCDMA. The random access uses the E-DCH (Enhanced Dedicated Channel) instead of the RACH in the R99 version to implement uplink transmission, so as to reduce the uplink transmission delay of the UE (User Equipment) and increase the uplink transmission rate.

 The uplink access transmission type of the UE in the R99 version is R99 PRACH (Physical Random Access Channel), and the RACH is mapped to one or more physical random access channels, which can be flexibly adapted according to the needs of the operator. Determine the RACH capacity. In the R8 version, the E-DCH uplink access transmission type of the UE includes an enhanced uplink of 10 ms TTI (Transmission Time Interval) and an enhanced uplink of 2 ms TTI, and the uplink information is transmitted at intervals of 10 ms and 2 ms, respectively.

In the process of implementing the present invention, the inventors have found that the prior art has the following disadvantages: The uplink access transmission type of the user equipment is an enhanced uplink or R8 of R8 10ms TTI. If the uplink total load of the current cell of the base station is too large, or the load of the corresponding access transmission type is too large, the uplink access of the user equipment fails, and the transmission path of the user equipment is congested. Summary of the invention

 The embodiment of the invention provides a control method, system and device for random access, which implements a base station to control a user equipment access transmission type according to a current access load condition.

 An embodiment of the present invention provides a method for controlling random access, including:

 Receiving an indication message sent by the base station, where the indication message carries the information of the converted access transmission type;

 And changing the access transmission type according to the converted access transmission type information to perform uplink access.

 An embodiment of the present invention provides a method for controlling random access, including:

 Receiving an access request of the user equipment;

 Detecting the uplink load occupancy;

 And sending, to the user equipment, an indication message, where the indication message carries the user equipment to convert access transmission type information, if the uplink load occupancy condition exceeds a preset value.

 The embodiment of the invention provides a random access control system, including:

 The base station is configured to: after receiving the access request of the user equipment, detect an uplink load occupation situation, and send an indication message to the user equipment if the uplink load occupancy condition exceeds a preset value;

 The user equipment is configured to receive an indication message sent by the base station, where the indication message carries the information of the converted access transmission type, and changes the access transmission type according to the converted access transmission type information to perform uplink access.

An embodiment of the present invention provides a base station, including: a receiving unit, configured to receive an access request of the user equipment;

 a detecting unit, configured to detect an uplink load occupancy situation;

 And an indication sending unit, configured to send an indication message to the user equipment, where the indication message carries the user equipment to convert the access transmission type information, when the receiving the access request is determined, and the uplink load occupancy exceeds a preset value .

 The embodiment of the invention provides a user equipment, including:

 a receiving unit, configured to receive an indication message sent by the base station, where the indication message carries information about the converted access transmission type;

 And an access unit, configured to change an access transmission type according to the converted access transmission type information to perform uplink access.

 In the embodiment of the present invention, when the UE initiates the uplink access, the network side controls the uplink access transmission type of the user equipment according to the current total uplink load condition of the current cell and the load condition of the various access transmission types. The access transmission type that occupies a large number of resources is converted into an access transmission type that occupies less resources, which reduces the total uplink load of the current cell of the base station or the corresponding access transmission type load, thereby reducing the congestion probability of the transmission path of the user equipment. . DRAWINGS

 1 is a flowchart of a method for controlling random access in Embodiment 1 of the present invention; FIG. 2 is a schematic diagram of an enhanced RACH in an embodiment of the present invention;

 3 is a schematic diagram of an enhanced RACH physical random access procedure in the embodiment of the present invention; FIG. 4 is a schematic diagram of a physical random access procedure in the embodiment of the present invention;

 FIG. 5 is a structural diagram of a control system for random access in an embodiment of the present invention. detailed description

In the embodiment of the present invention, the base station may be based on the current cell load and the access transmission type. Whether the load meets the system configuration requirements, and decides whether to notify the user equipment to convert the access transmission type. In order to achieve control of the access load, reasonable access transmission type control should be

R8 E-DCH→ R99 PRACH, or convert from a heavily loaded R8 E-DCH resource to a R8 E-DCH resource with a small load, that is, control the "degraded" use of the uplink access resource. The uplink load size generated by using the R8 E-DCH resource can be distinguished according to the length of the used or the maximum transmission power. For example, when the load of the current cell or the load of a certain access transmission type is relatively large, the base station can control the uplink load by instructing the user equipment to change the access transmission type. The access transmission type conversion includes: converting from an enhanced dedicated channel E-DCH access to a physical random access channel PRACH access; or from a heavily loaded R8 E-DCH resource to a small load R8 E-DCH resource access , that is, the degradation of the access transmission type.

 The control method for random access in the first embodiment of the present invention, as shown in FIG. 1, includes the following steps:

 Step 101: The base station receives an access request of the user equipment.

 Step 102: The base station detects the uplink load occupation, including the occupied load of the total load of the cell and the occupied load of the access transmission type. If the total load of the cell or the occupied load of the corresponding access transmission type exceeds a preset value, the user equipment is sent to the user equipment. Sending an indication message, instructing the user equipment to convert the access transmission type information.

 Step 103: The user equipment receives an indication message sent by the base station, where the indication message carries the information of the converted access transmission type.

 Step 104: The user equipment changes the access transmission type according to the converted access transmission type information to perform uplink access.

The method includes: determining whether the number of preamble retransmissions reaches a preset value, and if not, selecting, according to the access transmission type, a corresponding signature to send an access preamble in the next available access slot; if not, the access fails. . The control method for random access in the second embodiment of the present invention includes the following steps when converting the enhanced dedicated channel E-DCH access to the physical random access channel PRACH access:

 Step 201: The UE performs an access attempt of the 2ms TTI E-DCH, and sends an access request to the base station. After the MAC layer of the user equipment triggers the enhanced RACH physical random access procedure, the physical layer also needs to select a uplink access slot, signature, and preamble transmit power to transmit a preamble, just like the R99 physical random access procedure.

 Step 202: The Node B (base station) receives the access request of the UE, detects the corresponding access preamble, and determines whether to control the access transmission of the UE according to the uplink load situation at this time or the resource usage of the 2 ms TTI E-DCH. Type conversion.

 The enhanced RACH process is shown in Figure 2, including the preamble and resource allocation phases, the conflict resolution and resolution phase, the E-DCH data transmission phase, and the release resource phase. The access preamble and the resource allocation phase, the NodeB (base station) broadcasts all available uplink E-DCH (Enhanced Dedicated Channel) resources through system messages, where each set of uplink E-DCH resources Corresponding to a resource index number, the uplink E-DCH resource includes an uplink DPCH (Dedicated Physical Channel) information, an E-DCH information, an E-AGCH (E-DCH Absolute Grant Channel) information, and an E-RACH. Information, maximum uplink transmit power, TTI (Transmission Time Interval) length, etc. The base station divides the existing 16 signature signature sets into two sub-sets, and the PRACH access of R99 and the enhanced uplink access of R8 respectively use different signature subsets.

 When the UE sends the preamble corresponding to the R99 PRACH, or sends the preamble of the enhanced uplink corresponding to the R8 and does not configure the E-AICH, when the Node B detects the preamble signature, the AICH acknowledges the AI (Acquisition Indicator). The AI of the signature corresponding to the current pilot signature is +1, representing ACK, and is -1, representing NACK.

Each preamble signature is bound to a default resource configuration, when sending an enhancement to access R8 When the uplink corresponding preamble is configured and the E-AICH is configured, the AI of the signature corresponding to the current pilot signature is +1, representing the ACK, the access of the responded UE is accepted, and the default resource configuration is used; when the AI of the response is - 1 . On behalf of NACK, the responded UE needs to receive the E-AICH channel and read the configuration information carried by it.

 A signature in the signature set of the E-AICH channel transmission configuration, the 16 signatures in the signature set being orthogonal to the 16 signatures in the signature set of the AICH. The number of signatures that E-AICH can send is 16, and the combination of different E-AI values (+1 or -1) of the same signature can indicate up to 32 values, but in a given access slot. E-AICH can only indicate one of 32 values at most, which means that at most one signature with no E-AI is 0. One of the 32 values that can be represented represents NACK, and the rest can represent the index number of the uplink E-DCH resource. The index number is obtained by the default resource configuration of the accessed access preamble signature and the offset, and the combination of different signatures carried by the E-AICH and its E-AI indicates different resource offsets. The combination of the signature of the E-AICH and the E-AI value is associated with the uplink E-DCH resource offset, and the content and index number of the resource are broadcast by the system message.

 The resource indication method is shown in Table 1, where X represents the access preamble signature of the NACK replied by the AICH, and Y represents the total number of E-DCH resources in the cell. Therefore, the combination of the signature and the E-AI value carried by the E-AICH indicates the offset of the default resource relative to the preamble signature. After receiving the indication, the UE uses the resource of the corresponding index number for uplink transmission.

 Table 1 shows the method of resource allocation information converted by E-AICH indication

 UE NodeB NodeB NodeB E-DCH transmission AICH transmission E-AI E-AICH resource configuration index Signature transmission signature on E-AICH transmission signature

 1 K-D +1 0 NACK

1 K-D -1 Retry R99

PRACH ¹ Ki) +1 1 Level down

¹ Ki) -1 ( X+1 ) mod Y

¹ Ki) +1 2 ( X+2 ) mod Y

¹ Ki) -1 ( X+3 ) mod Y

¹ Ki) +1 3 ( X+4 ) mod Y

¹ Ki) -1 ( X+5 ) mod Y

¹ Ki) +1 4 ( X+6 ) mod Y

¹ Ki) -1 ( X+7 ) mod Y

 +1 5 ( X+8 )

¹ Ki)

 Mod Y

¹ Ki) -1 ( X+9 ) mod Y

¹ Ki) +1 6 ( X+10 ) mod Y

¹ Ki) -1 ( X+11 ) mod Y

¹ Ki) +1 7 ( X+12 ) mod Y Ki) -1 ( X+13 )

¹

 Mod Y

 K-i) +1 8 ( X+14 )

¹

 Mod Y

 K-i) -1 ( X+15 )

¹

 Mod Y

 K-i) +1 9 ( X+16 )

¹

 Mod Y

 K-i) -1 ( X+17 )

¹

 Mod Y

 K-i) +1 10 ( X+18 )

¹

 Mod Y

 K-i) -1 ( X+19 )

¹

 Mod Y

 K-i) +1 11 ( X+20 )

¹

 Mod Y

 K-i) -1 ( X+21 )

¹

 Mod Y

 K-i) +1 12 ( X+22 )

¹

 Mod Y

 K-i) -1 ( X+23 )

¹

 Mod Y

 K-i) +1 13 ( X+24 )

¹

 Mod Y

 K-i) -1 ( X+25 )

¹

Mod Y 1 Ki) +1 14 ( X+26 ) mod Y

 1 K-i) -1 ( X+27 ) mod Y

 1 K-i) +1 15 ( X+28 ) mod Y

 1 Ki) -1 ( X+29 ) mod Y If the current cell load is large, or there is no available 2ms TTI E-DCH resource, the E-AICH is used to instruct the UE to use the 10ms TTI E-DCH resource for uplink transmission, or use R99 PRACH access. The E-AICH indication conversion method is as shown in Table 1, adding an indication of transition to R99 PRACH: "Retry R99 PRACH", and a downgrade indication "Level down" for accessing the R8 E-DCH resource, where the downgrade indicates "Level down" " is optional, ie E-AICH may not indicate "Level down".

 The schematic diagram when using R99 PRACH is shown in Figure 4, where the access procedure includes the following steps:

 1. Determine and select an uplink access slot according to the available RACH (Access Random Access Channel) set of the ASC (Access Service Class).

 2. Randomly select a signature in the set of available signatures (Signatures) for the given ASC.

 3. Set the value of the preamble retransmission counter to the maximum number of preamble retransmissions.

 4. Determine the command preamble power based on the preamble initial power and the minimum power requirement.

5. Set the appropriate preamble transmit power based on the commanded preamble power, as well as the minimum power requirement and maximum allowable power. Then use the selected uplink access slot, signature and preamble The transmit power transmits a preamble.

 6, determining whether an acquisition indication (ACK or NACK) corresponding to the selected signature is detected in the downlink access slot corresponding to the selected uplink access slot; if yes, proceeding to step 107; If not, perform the following steps:

 a. selecting the next available access slot in a given set of available RACH subchannels of the ASC;

 b. randomly select a new signature in a given set of signatures of the ASC; c. Increase the commanded preamble power by a power ramp. If the commanded preamble power exceeds the maximum allowable power by 6 dB, it is necessary to report the physical layer status "No ACK on AICH" to the MAC (Media Access Control) layer and exit the current physical random access procedure;

 d. Decrease the value of the preamble retransmission counter by one;

 e. If the value of the preamble retransmission counter is greater than 0, step 105 is repeated, otherwise the status "no ACK on AICH" needs to be reported to the MAC and the current physical random access procedure is exited.

 7 . If a NACK acquisition indication corresponding to the selected signature is detected in the downlink access slot corresponding to the selected uplink access slot, the physical layer status "NACK received on the AICH" needs to be reported. The MAC layer exits the current physical random access procedure; if an ACK capture indication corresponding to the selected signature is detected in the downlink access slot corresponding to the selected uplink access slot, then The random access message is started after the uplink access slot 3 or 4 uplink access slots of the last transmission preamble.

 8. Report the physical layer status "RACH message sent" to the MAC layer and exit the current physical random access procedure.

Step 203: After the accessed UE receives the "Retry R99 PRACH" indication through the E-AICH, if the number of preamble retransmissions does not reach the configured maximum value, the R99 is continued. The access of the PRACH, in the next available access slot, selects the corresponding signature to continue to send an access preamble, and the power of the access preamble can no longer climb. After the received UE receives the "Level down" indication through the E-AICH, if the number of preamble retransmissions does not reach the configured maximum value, the R8 enhanced uplink access is continued, and the request for small enhanced uplink resources is requested. The available access slots, selecting the corresponding signature to continue to send an access preamble, the power of the access preamble can no longer climb. For example, an access attempt of 10 ms TTI E-DCH is performed in the next available access slot. In Table 2, if the signature number sent by the E-AICH is S, E-AI is EAI, and the indicated resource offset is 0. Then when the "Retry R99 PRACH" indication is included, without the "Level down" indication,

² ; when both "Retry R99 PRACH" and "Level down" are included

0 = 2(5 -1) + ^-^

In the case of the indication, ² ; when the "Retry R99 PRACH" and "Level down" instructions are not available, ² .

 In the embodiment of the present invention, a random access control system, as shown in FIG. 5, includes: a base station 100, configured to: after receiving an access request of a user equipment, detect an uplink load occupation situation, if the uplink load occupancy situation exceeds The preset value sends an indication message to the user equipment.

 The user equipment 200 is configured to receive an indication message sent by the base station, where the indication message carries the information of the converted access transmission type, and changes the access transmission type according to the converted access transmission type information to perform uplink access. The conversion access transmission type includes: converting from an enhanced dedicated channel E-DCH access to a physical random access channel PRACH access; or from a heavily loaded R8 E-DCH resource to a small load R8 E-DCH resource connection In.

 The base station 100 includes:

 The receiving unit 110 is configured to receive an access request of the user equipment.

The detecting unit 120 is configured to detect an uplink load occupancy situation. The indication sending unit 130 is configured to send an indication message to the user equipment 200, where the indication message carries the user equipment 200 to convert the access transmission type information, when it is determined that the access request is received, and the uplink load occupancy exceeds a preset value. .

 User equipment 200 includes:

 The receiving unit 210 is configured to receive an indication message sent by the base station, where the indication message carries the converted access transmission type information.

 The access unit 220 is configured to change the access transmission type according to the converted access transmission type information to perform uplink access.

 The determining unit 230 is configured to determine whether the number of preamble retransmissions reaches a preset value, and if not, select a corresponding signature to send an access preamble in the next available access slot according to the access transmission type; if yes, Determine access failure.

 In the embodiment of the present invention, the base station controls the uplink access transmission type of the user equipment according to the load condition, and converts the access transmission type that occupies more resources into the access transmission type that occupies less resources, and reduces the uplink of the current cell of the base station. The total load or the corresponding access transmission type load, thereby reducing the congestion probability of the transmission path of the user equipment.

 Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by hardware, or can be implemented by means of software plus necessary general hardware platform, and the technical solution of the present invention. It can be embodied in the form of a software product that can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for making a computer device (may It is a personal computer, a server, or a network device, etc.) that performs the methods described in various embodiments of the present invention.

 In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of 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.

Claims

Rights request A random access control method, comprising:  Receiving an indication message sent by the base station, where the indication message carries the information of the converted access transmission type;  And changing the access transmission type according to the converted access transmission type information to perform uplink access.  2. The method for controlling random access according to claim 1, wherein the changing the access transmission type according to the converted access transmission type information for uplink access comprises:  If the number of preamble retransmissions does not reach the preset value, according to the access transmission type, the corresponding preamble signature is selected to send the access preamble in the next available access slot.  The control method for random access according to claim 1 or 2, wherein the converted access transmission type information is a Retry R99 PRACH indication, and the E-DCH access is converted from an enhanced dedicated channel to a physical random connection. Incoming channel PRACH access; or the converted access transmission type indication is a degraded indication, switching from a heavily loaded R8 E-DCH resource access to a small load R8 E-DCH resource access.  4. A random access control method, comprising:  Receiving an access request of the user equipment;  Detecting the uplink load occupancy; Sending an indication message to the user equipment, where the indication message carries the user equipment to convert an access transmission type letter, if the uplink load occupancy exceeds a preset value Interest.  The method for controlling random access according to claim 4, wherein the uplink load occupancy situation comprises:  The occupied load of the total load of the cell and/or the occupied load of the type of access transmission. The control method of the random access according to claim 5, wherein the occupied load of the access transmission type comprises:  2ms transmission time interval ΤΉ E-DCH resource usage.  The random access control method according to any one of claims 4 to 6, wherein the control method is characterized in that  The user equipment converts the access transmission type information to a Retry R99 PRACH indication,  Instructing to convert from an enhanced dedicated channel E-DCH access to a physical random access channel PRACH access;  Or the user equipment converts the access transmission type information to a degraded indication, and converts from a large R8 E-DCH resource access to a small load R8 E-DCH resource access.  8. A random access control system, comprising:  The base station is configured to: after receiving the access request of the user equipment, detect an uplink load occupation situation, and send an indication message to the user equipment if the uplink load occupancy condition exceeds a preset value; The user equipment is configured to receive an indication message sent by the base station, where the indication message carries the information of the converted access transmission type, and changes the access transmission type according to the converted access transmission type information to perform uplink access. The control system for random access according to claim 8, wherein the changing the access transmission type according to the converted access transmission type information for uplink access comprises: converting from the enhanced dedicated channel E-DCH access to Physical random access channel PRACH access; or from a heavily loaded R8 E-DCH resource access to a small load R8 E-DCH resource access.  10. A base station, comprising:  a receiving unit, configured to receive an access request of the user equipment;  a detecting unit, configured to detect an uplink load occupancy situation;  And an indication sending unit, configured to send an indication message to the user equipment, where the indication message carries the user equipment to convert the access transmission type information, when the receiving the access request is determined, and the uplink load occupancy exceeds a preset value .  11. A user equipment, comprising:  a receiving unit, configured to receive an indication message sent by the base station, where the indication message carries information about the converted access transmission type;  And an access unit, configured to change an access transmission type according to the converted access transmission type information to perform uplink access.  The user equipment of claim 11, further comprising: a determining unit, configured to determine whether the number of preamble retransmissions reaches a preset value, and if not, according to the access transmission type, in the next available The access slot selects a corresponding signature to send an access preamble; if it is reached, it determines that the access fails.