CN101820663A - Wireless access control method and device in long term evolution access system - Google Patents

Abstract

The invention discloses a wireless access control method and a wireless access control device in a long term evolution (LTE) access system. The wireless access control method comprises the following steps of: calculating the number of total resource blocks in a cell; calculating the number of resource blocks used by accessed service in the cell; calculating the number of resource blocks needed to be used by service to be accessed; judging whether the service to be accessed can be accessed to the cell according to the number of the total resource blocks in the cell, the number of the resource blocks used by the accessed service in the cell and the number of the resource blocks needed to be used by the service to be accessed, if so, permitting the service to be accessed to be accessed to the cell, otherwise, refusing to access the service to be accessed to the cell. The technical scheme of the invention can realize the wireless access control based on the resource blocks.

Description

Wireless access control method and device in long term evolution access system

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for controlling wireless access in a long term evolution access system.

Background

Radio resources of a cell in a Long Term Evolution (LET) access system are limited, and in order to access bearers as many as possible, and simultaneously ensure the rate of the access bearers and improve the utilization rate of the radio resources, a radio access network needs to perform effective access control.

The conventional access control method for the radio access network comprises the following steps: online UE number limitation, active bearer number limitation, hardware resource utilization, and the like.

However, according to the characteristics of the wireless communication system, the access bottleneck is mainly the time-frequency resource of the air interface, which is referred to as a resource block herein. In a long term evolution system, no scheme for performing radio access control according to time-frequency resources exists at present.

Disclosure of Invention

The invention provides a wireless access control method in an LTE access system, which can realize wireless access control based on resource blocks;

the invention also provides a wireless access control device in the LTE access system, and the device can realize wireless access control based on the resource block.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the invention discloses a wireless access control method in an LTE access system, which comprises the following steps:

calculating the total number of resource blocks of the cell;

calculating the number of resource blocks used by accessed services in a cell;

calculating the number of resource blocks needed to be used by the service to be accessed;

and judging whether the service to be accessed can be accessed to the cell or not according to the total number of the resource blocks of the cell, the number of the resource blocks used by the accessed service in the cell and the number of the resource blocks needed to be used by the service to be accessed, if so, allowing the service to be accessed to the cell, otherwise, refusing the service to be accessed to the cell.

The invention also discloses a wireless access control device in the LTE access system, which comprises: the device comprises a total resource calculation module, a used resource calculation module, a to-be-used resource calculation module and an access judgment module, wherein:

the total resource calculation module is used for calculating the total resource block number of the cell and sending the total resource block number to the access judgment module;

the used resource calculation module is used for calculating the number of resource blocks used by the accessed service in the cell and sending the resource blocks to the access judgment module;

the resource to be used calculation module is used for calculating the number of resource blocks required to be used by the service to be accessed and sending the number of the resource blocks to the access judgment module;

and the access judging module is used for judging whether the service to be accessed can be accessed into the cell or not according to the total number of the resource blocks of the cell, the number of the resource blocks used by the accessed service in the cell and the number of the resource blocks needed to be used by the service to be accessed, if so, the service to be accessed is allowed to be accessed into the cell, otherwise, the service to be accessed is refused to be accessed into the cell.

It can be seen from the above that, the present invention first calculates the total number of resource blocks in a cell, the number of resource blocks used by an accessed service in the cell, and the number of resource blocks needed to be used by a service to be accessed, and then judges whether the service to be accessed can be accessed to the cell according to the total number of resource blocks in the cell, the number of resource blocks used by the accessed service in the cell, and the number of resource blocks needed to be used by the service to be accessed, if so, the service to be accessed is allowed to be accessed to the cell, otherwise, the service to be accessed is denied to be accessed to the cell, and wireless access control can be realized based on resource blocks.

Drawings

Fig. 1 is a flowchart of a radio access control method in an LTE access system according to an embodiment of the present invention;

fig. 2 is a block diagram of a structure of a radio access control device in an LTE access system according to an embodiment of the present invention.

Detailed Description

The core idea of the invention is that when a new service is accessed, the number of resource blocks needed to be used by the new service to be accessed is calculated, on the basis, the number of resource blocks occupied by the existing service in a cell is added, and is compared with the total number of resource blocks in the cell, if the number of resource blocks exceeds the total number of resource blocks in the cell, the access is failed, otherwise, the access is successful.

Fig. 1 is a flowchart of a radio access control method in an LTE access system according to an embodiment of the present invention. As shown in fig. 1, the method includes:

step 101, calculating the total resource block number of the cell. Here, a resource block refers to a time-frequency resource.

In this step, the total number of resource blocks in a cell includes: the total uplink resource block number of the cell and the total downlink resource block number of the cell.

Step 102, calculating the number of resource blocks used by the accessed service in the cell.

In this step, the number of resource blocks used by the accessed service in the cell includes: the number of resource blocks used by the accessed service uplink in the cell and the number of resource blocks used by the accessed service downlink in the cell.

103, calculating the number of resource blocks needed by the service to be accessed;

in this step, the number of resource blocks to be used for the service to be accessed includes: the number of resource blocks required for uplink transmission of the service to be accessed and the number of resource blocks required for downlink transmission of the service to be accessed.

And step 104, judging whether the service to be accessed can be accessed to the cell according to the total number of the resource blocks of the cell, the number of the resource blocks used by the accessed service in the cell and the number of the resource blocks needed to be used by the service to be accessed, if so, allowing the service to be accessed to the cell, otherwise, refusing the service to be accessed to the cell.

In this step, when the sum of the number of resource blocks used by the uplink of the accessed service and the number of resource blocks required by the uplink transmission of the service to be accessed in the cell is less than the total number of uplink resource blocks of the cell, and the sum of the number of resource blocks used by the downlink of the accessed service and the number of resource blocks required by the downlink transmission of the service to be accessed in the cell is less than the total number of downlink resource blocks of the cell, the service to be accessed is allowed to be accessed into the cell, otherwise the service to be accessed is refused to be accessed into the cell; or, when the sum of the number of resource blocks used by the accessed service uplink in the cell and the number of resource blocks required by the uplink transmission of the service to be accessed is less than the sum of the number of cell uplink total resource blocks multiplied by a preset coefficient, and the sum of the number of resource blocks used by the accessed service downlink in the cell and the number of resource blocks required by the downlink transmission of the service to be accessed is less than the sum of the number of cell downlink total resource blocks multiplied by the preset coefficient, allowing the service to be accessed to access the cell, otherwise, refusing the service to be accessed to access the cell.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in detail below with reference to specific embodiments.

Calculation of total resource blocks of first and second cells

In the present invention, the total number of uplink and downlink resource blocks of a cell can be calculated according to the cell configuration, and in this embodiment, a 10ms radio frame is used as a granularity. For a Time Division Duplex (TDD) system, the total number of resource blocks in a cell is related to the system bandwidth and the uplink and downlink configuration, and for a Frequency Division Duplex (FDD) system, the total number of resource blocks in a cell is related to the uplink and downlink bandwidth.

After the cell is successfully established, the channel bandwidth and the uplink and downlink configuration are determined, and the number of uplink subframes N in the wireless frame is determined_ul-SFAnd a downlink subframe number N in a radio frame_dl-SFIs determined. For example, table 5.6-1 in 3GPP 36101 is channel bandwidth configuration, specifically as shown in table 1 below, and table 4.2-2 in 3GPP 36211 is uplink configuration, specifically as shown in table 2 below.

Channel bandwidth (ChannelBandwidth BW)Channel)[MHz]	1.4	3	5	10	15	20
							Transmission Bandwidth configuration (Transmission Bandwidth configuration N)RB)	6	15	25	50	75	100

TABLE 1

TABLE 2

For the TDD mode, the total number of uplink resource blocks N of the cell is calculated according to the following formula_ul-PRBAnd the total downlink resource block number N of the cell_dl-PRB：

N_ul-PRB＝N_RB×N_ul-SF，

N_dl-PRB＝N_RB×N_dl-SF，

Wherein N is_RBConfiguring parameters for transmission bandwidth, N_ul-SFIs the number of uplink subframes, N, in a radio frame_dl-SFIs the number of downlink subframes in a radio frame.

For the FDD mode, the total uplink resource block number N of the cell is calculated according to the following formula_ul-PRBAnd the total downlink resource block number N of the cell_dl-PRB：

N_ul-PRB＝N_ul-RB×N_SF，

N_dl-PRB＝N_dl-RB×N_SF，

Wherein N is_ul-RBConfiguring a parameter, N, for the uplink transmission bandwidth_dl-RBConfiguring a parameter, N, for the downlink transmission bandwidth_SFIs the number of subframes within a radio frame.

N used in the above formula_RB、N_ul-SF、N_dl-SF、N_ul-RB、N_dl-RBAnd N_SFThe isoparameters may be obtained from an Operations and Maintenance (OM) system, cell context.

Measurement of related parameters

In order to calculate the number of resource blocks used as indicated by the accessed service and the number of resource blocks to be used for accessing, the following parameters about the cell and the user need to be measured:

1. about a cell

1) Actual average rate R of uplink of accessed service in cell_ul-aThat is, the actual average rate of all the existing uplink services in the cell, including the initial transmission and the retransmission;

2) actual downlink average rate R of accessed service in cell_dl-aThat is, the actual average rate of all downlink services existing in the cell, including initial transmission and retransmission;

3) the number N of resource blocks occupied by each wireless frame is actually averaged by the uplink service in the accessed service in the cell_ul-a；

4) The downlink service in the accessed service in the cell actually averages the number N of resource blocks occupied by each wireless frame_dl-a；

5) Modulation and coding Scheme (Modulation and coding Scheme) MCS (Modulation and coding Scheme) of cell uplink_ul-CELL；

6) Cell downlink average modulation and coding scheme parameter MCS_dl-CELL；

7) Cell uplink average retransmission rate lambda_ul-CELL；

8) Cell downlink average retransmission rate lambda_ul-CELL；

2. About the user

1) User uplink average modulation and coding scheme parameter MCS_ul-UE；

2) User downlink average modulation and coding scheme parameter MCS_dl-UE；

3) User uplink average retransmission rate lambda_ul-UE；

4) User downlink averagingRetransmission rate lambda_dl-UE。

Thirdly, calculating the number of resource blocks used by the accessed service in the cell

In the invention, the number N of resource blocks used by the accessed service uplink in the cell is calculated according to the following formula_ul-oAnd the number N of resource blocks used by the downlink of the accessed service in the cell_dl-o：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>ul</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>dl</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>,</mo></mrow></math>

Wherein R is_ul-tIs the sum of the uplink rates, R, of the accessed services in the cell_dl-tIs the sum of the downlink rates of the accessed services in the cell. R_ul-tAnd R_dl-tAll the data are statistical values, and the data need to be added or subtracted cumulatively after the service bearer is established or released, and are recorded in the cell context.

Fourthly, calculating the number of resource blocks needed to be used by the service to be accessed

When the uplink and downlink guarantee rate of the service to be accessed is GBR_ulAnd GBR_dl(in bps), the equivalent number of bits to be transmitted in a radio frame can be expressed as:

<math><mrow><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>RF</mi></mrow></msub><mo>=</mo><msub><mi>GBR</mi><mi>ul</mi></msub><mo>&times;</mo><mfrac><mrow><mn>10</mn><mi>ms</mi></mrow><mrow><mn>1000</mn><mi>ms</mi></mrow></mfrac></mrow></math>

<math><mrow><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>RF</mi></mrow></msub><mo>=</mo><msub><mi>GBR</mi><mi>dl</mi></msub><mo>&times;</mo><mfrac><mrow><mn>10</mn><mi>ms</mi></mrow><mrow><mn>1000</mn><mi>ms</mi></mrow></mfrac></mrow></math>

here, one radio frame is taken to be 10ms, B_ul-RFThe bit number of uplink transmission of a radio frame, B, is used for ensuring the uplink rate of the service to be accessed_dl-RFThe bit number of downlink transmission of a radio frame is used for ensuring the downlink rate of the service to be accessed.

According to the uplink and downlink MCS parameters, the bit number B of uplink transmission of each resource block can be obtained by looking up the table 7.1.7.1-1(Modulation and TBS index table for PDSCH), the table 7.1.7.2-1(Transport block size table) and the table 8.6.1-1(Modulation, TBS index and redundancy version table for PUSCH) in the 3GPP 36213_ul-PRBAnd bit number B of downlink transmission of each resource block_dl-PRB. When the service to be accessed is the first load of the user or the load of the switching user, the MCS is used for controlling the switching of the load_ul-CELLObtaining B_ul-PRBAccording to MCS_dl-CELLObtaining B_dl-PRB(ii) a When the service to be accessed is the load initiated after the on-line user, according to the MCS_ul-UEObtaining B_ul-PRBAccording to MCS_dl-UEObtaining B_dl-PRB. Table 7.1.7.1-1, Table 7.1.7.2-1, and Table 8.6.1-1 are the same as Table three, Table four, and Table five, respectively, below:

watch III

Watch four

Watch five

I.e. for the downlink: firstly, look up table three according to MCS parameter, wherein the MCS parameter is corresponding to I in table three_MCSParameter, find the corresponding I_TBSParameter, then according to I_TBSLooking up table four to find the number of resource blocks N_PRBA value corresponding to 1, which is the number of bits B of downlink transmission of each resource block_dl-PRB. For example, according to Table four, when I_TBSWhen the parameter is 1, B_dl-PRBIs 24 when I_TBSWhen the parameter is 2, B_dl-PRB32, and so on.

Similarly, for the uplink, first look up table five according to the MCS parameter, whichThe inner MCS parameter is I in the corresponding table five_MCSParameter, find the corresponding I_TBSParameter, then according to I_TBSLooking up table four to find the number of resource blocks N_PRBA value corresponding to 1, which is the number of bits B of uplink transmission of each resource block_ul-PRB。

In order to ensure the rate required by the higher-layer service, the resources required by transmission are divided into two parts, namely the resources required by initial transmission and the resources required by retransmission.

Calculating the number N of resource blocks needed by the initial transmission of the uplink service of the service to be accessed according to the following formula_ul-iAnd the number N of resource blocks needed by the initial transmission of the downlink service of the service to be accessed_dl-i：

$N_{\mathrm{ul}-i}=\frac{B_{\mathrm{ul}-\mathrm{RF}}}{B_{\mathrm{ul}-\mathrm{PRB}}},$

$N_{\mathrm{dl}-i}=\frac{B_{\mathrm{dl}-\mathrm{RF}}}{B_{\mathrm{dl}-\mathrm{PRB}}},$

Wherein, B_ul-RFAnd B_dl-RFRespectively ensuring the uplink and downlink rates of a service to be accessed, the bit number of uplink transmission and the bit number of downlink transmission of a wireless frame; b is_ul-PRBAnd B_dl-PRBRespectively representing the uplink transmission bit number and the downlink transmission bit number of each resource block;

calculating the number N of resource blocks needed by the uplink service retransmission of the service to be accessed according to the following formula_ul-rAnd service to be accessedThe number of resource blocks N required for downlink service retransmission_dl-r：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>ul</mi></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>dl</mi></msub><mo>,</mo></mrow></math>

Wherein λ is_ulFor the uplink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switching user, the λ_ulTaking the average retransmission rate lambda of the cell uplink_ul-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_ulAverage retransmission rate lambda of user uplink_ul-UE；λ_dlFor the downlink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switched user, the λ_dlTaking the average downlink retransmission rate lambda of the cell_dl-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_dlUser downlink average retransmission rate lambda_dl-UE；

Finally, the calculation is carried out according to the following formula:

ΔN_ul＝N_ul-i+N_ul-r，

ΔN_dl＝N_dl-i+N_dl-r，

wherein, Δ N_ulNumber of resources, Δ N, required for uplink transmission of a service to be accessed_dlThe number of resources required for downlink transmission of the service to be accessed.

Fifth, access judgment

Whether the following two inequalities are satisfied simultaneously is judged according to the above calculation:

N_ul-o+ΔN_ul≤N_ul-PRB×ρ

N_dl-o+ΔN_dl≤N_dl-PRB×ρ

and when the two inequalities are simultaneously satisfied, allowing the service to be accessed to access the cell, and otherwise, refusing the service to be accessed to access the cell.

And rho is a receiving threshold coefficient, and a value between 0 and 1 is taken. This is because the dropped call at handover tends to cause user dissatisfaction more easily than the initial access rejection, so a mechanism for reserving resources is introduced here for the handover user. For example, ρ is 0.9 when the initially accessed user bearer is admitted, and ρ is 1 when the switched user bearer is admitted. This is equivalent to reserving 10% of the resources for the handover user, and when the cell resource block usage reaches 90%, all bearers of the initial access user are rejected, but the reserved resources can be used for the handover user.

Next, a composition structure of the radio access control apparatus in the present invention is given.

Fig. 2 is a block diagram of a structure of a radio access control device in an LTE access system according to an embodiment of the present invention. As shown in fig. 2, the apparatus includes: a total resource calculation module 201, a used resource calculation module 202, a to-be-used resource calculation module 203, and an access decision module 204, wherein:

a total resource calculation module 201, configured to calculate the total number of resource blocks in a cell, and send the total number of resource blocks to an access decision module 204;

a used resource calculation module 202, configured to calculate the number of resource blocks used by an accessed service in a cell, and send the number of resource blocks to an access decision module 204;

the to-be-used resource calculating module 203 is configured to calculate the number of resource blocks that need to be used by the to-be-accessed service, and send the number of resource blocks to the access determining module 204;

an access decision module 204, configured to determine whether the service to be accessed can be accessed to the cell according to the total number of resource blocks of the cell, the number of resource blocks used by the service already accessed in the cell, and the number of resource blocks needed to be used by the service to be accessed, if so, the service to be accessed is allowed to be accessed to the cell, otherwise, the service to be accessed is denied to be accessed to the cell.

As shown in fig. 2, the apparatus further comprises: a parameter acquisition module 205;

the parameter obtaining module 205 is configured to obtain a transmission bandwidth configuration parameter N in a TDD mode_RBAn uplink subframe number N in a radio frame_ul-SFAnd a downlink subframe number N in a radio frame_dl-SFAnd sending the data to the total resource calculation module; in FDD mode, the method is used for obtaining the configuration parameter N of the uplink transmission bandwidth_ul-RBDownlink transmission bandwidth configuration parameter N_dl-RBAnd the number of subframes N within one radio frame_SFAnd sends it to the total resource calculation module 201;

the total resource calculating module 201 is configured to calculate the total uplink resource block number N of the cell according to the following formula_ul-PRBAnd the total downlink resource block number N of the cell_dl-PRB：

For the TDD mode, the transmission rate is,

N_ul-PRB＝N_RB×N_ul-SF，

N_dl-PRB＝N_RB×N_dl-SF，

for the case of the FDD mode,

N_ul-PRB＝N_ul-RB×N_SF，

N_dl-PRB＝N_dl-RB×N_SF。

as shown in fig. 2, the apparatus further comprises: a measurement module 206;

the measurement module 206 is configured to measure an uplink actual average rate R of an accessed service in a cell_ul-aActual downlink average rate R of accessed service in cell_dl-aCell uplink average retransmission rate lambda_ul-CELLCell downlink average retransmission rate lambda_dl-CELLThe number N of resource blocks occupied by each wireless frame is actually averaged by the uplink service in the accessed service in the cell_ul-aAnd the number N of resource blocks occupied by each radio frame is actually averaged by the downlink service in the accessed service in the cell_dl-aAnd sends the above parameters to the used resource calculation module 202;

the used resource calculating module 202 is configured to obtain an uplink rate sum R of the accessed service in the cell from the context of the cell_ul-tAnd the sum R of the downlink rates of the accessed services in the cell_dl-tAnd calculating the number N of resource blocks used by the accessed service uplink in the cell according to the following formula_ul-oAnd the number N of resource blocks used by the downlink of the accessed service in the cell_dl-o：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>ul</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>dl</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>.</mo></mrow></math>

The measurement module 206 is further configured to measure an uplink average retransmission rate λ of the cell_ul-CELLCell downlink average retransmission rate lambda_dl-CELLUser uplink average retransmission rate lambda_ul-UEUser downlink average retransmission rate lambda_dl-UECell uplink average modulation and coding scheme MCS_ul-CELLCell downlink average modulation and coding scheme MCS_dl-CELLUser uplink average modulation and coding scheme MCS_ul-UEAnd user downlink average modulation and coding scheme MCS_dl-UEAnd sends it to the resource to be used calculation module 203;

the to-be-used resource calculating module 203 is configured to calculate a resource to be used according to the MCS when the to-be-accessed service is a first bearer of the user or a bearer of the handover user_ul-CELLObtaining the bit number B of uplink transmission of each resource block_ul-PRBAccording to MCS_dl-CELLObtaining the bit number B of downlink transmission of each resource block_dl-PRB(ii) a When the service to be accessed is a load initiated after the on-line user, the method is used for carrying out the load according to the MCS_ul-UEObtaining the bit number B of uplink transmission of each resource block_ul-PRBAccording to MCS_dl-UEObtaining the bit number B of downlink transmission of each resource block_dl-PRB(ii) a Used for obtaining the bit number B of a wireless frame uplink transmission for ensuring the uplink and downlink rates of the service to be accessed according to the uplink guaranteed rate of the service to be accessed_ul-RFAnd bit number B of downlink transmission_dl-RF；

A to-be-used resource calculating module 203, configured to calculate the upper limit of the to-be-accessed service according to the following formulaNumber N of resource blocks needed for initial transmission of business affairs_ul-iAnd the number N of resource blocks needed by the initial transmission of the downlink service of the service to be accessed_dl-i：

$N_{\mathrm{ul}-i}=\frac{B_{\mathrm{ul}-\mathrm{RF}}}{B_{\mathrm{ul}-\mathrm{PRB}}},$

$N_{\mathrm{dl}-i}=\frac{B_{\mathrm{dl}-\mathrm{RF}}}{B_{\mathrm{dl}-\mathrm{PRB}}},$

A to-be-used resource calculating module 203, configured to calculate the number N of resource blocks required by uplink service retransmission of the to-be-accessed service according to the following formula_ul-rAnd the number N of resource blocks needed by the retransmission of the downlink service of the service to be accessed_dl-r：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>ul</mi></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>dl</mi></msub><mo>,</mo></mrow></math>

Wherein λ is_ulFor the uplink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switching user, the λ_ulTaking the average retransmission rate lambda of the cell uplink_ul-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_ulAverage retransmission rate lambda of user uplink_ul-UE；λ_dlFor the downlink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switched user, the λ_dlTaking the average downlink retransmission rate lambda of the cell_dl-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_dlUser downlink average retransmission rate lambda_dl-UE；

Finally, the to-be-used resource calculating module 203 is configured to calculate the number of resources Δ N required for uplink transmission of the to-be-accessed service according to the following formula_ulAnd the number of resources delta N required for downlink transmission of the service to be accessed_dl：

ΔN_ul＝N_ul-i+N_ul-r，

ΔN_dl＝N_dl-i+N_dl-r。

In fig. 2, the access determining module 204 is configured to allow the service to be accessed to access the cell when the sum of the number of resource blocks used for uplink of the accessed service and the number of resource blocks required for uplink transmission of the service to be accessed in the cell is smaller than the total number of uplink resource blocks of the cell, and the sum of the number of resource blocks used for downlink of the accessed service and the number of resource blocks required for downlink transmission of the service to be accessed in the cell is smaller than the total number of downlink resource blocks of the cell, otherwise, deny the service to be accessed to access the cell;

or,

the access decision module 204 is configured to allow the service to be accessed to access the cell when the sum of the number of resource blocks used by the uplink of the accessed service and the number of resource blocks required for uplink transmission of the service to be accessed in the cell is smaller than the sum of the number of uplink total resource blocks of the cell multiplied by a preset coefficient, and the sum of the number of resource blocks used by the downlink of the accessed service and the number of resource blocks required for downlink transmission of the service to be accessed in the cell is smaller than the sum of downlink total resource blocks of the cell multiplied by the preset coefficient, and otherwise, deny the service to be accessed to access the cell.

In summary, the present invention is a technical solution that first calculates the total number of resource blocks in a cell, the number of resource blocks used by an accessed service in the cell, and the number of resource blocks needed to be used by a service to be accessed, and then determines whether the service to be accessed can be accessed to the cell according to the total number of resource blocks in the cell, the number of resource blocks used by the accessed service in the cell, and the number of resource blocks needed to be used by the service to be accessed, and if so, allows the service to be accessed to the cell, otherwise, denies the service to be accessed to the cell, and can implement wireless access control based on resource blocks.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A wireless access control method in a Long Term Evolution (LTE) access system is characterized by comprising the following steps:

calculating the total number of resource blocks of the cell;

calculating the number of resource blocks used by accessed services in a cell;

calculating the number of resource blocks needed to be used by the service to be accessed;

and judging whether the service to be accessed can be accessed to the cell or not according to the total number of the resource blocks of the cell, the number of the resource blocks used by the accessed service in the cell and the number of the resource blocks needed to be used by the service to be accessed, if so, allowing the service to be accessed to the cell, otherwise, refusing the service to be accessed to the cell.

2. The method of claim 1, wherein the total number of resource blocks in the cell comprises: the total uplink resource block number of the cell and the total downlink resource block number of the cell;

the calculating the total number of the resource blocks of the cell comprises:

for the TDD mode, the total number N of uplink resource blocks of the cell is calculated according to the following formula_ul-PRBAnd the total downlink resource block number N of the cell_dl-PRB：

N_ul-PRB＝N_RB×N_ul-SF，

N_dl-PRB＝N_RB×N_dl-SF，

Wherein N is_RBConfiguring parameters for transmission bandwidth, N_ul-SFIs the number of uplink subframes, N, in a radio frame_sl-SFIs the number of downlink subframes in a radio frame;

for FDD mode, the total number of uplink resource blocks N of the cell is calculated according to the following formula_ul-PRBAnd the total downlink resource block number N of the cell_dl-PRB：

N_ul-PRB＝N_ul-RB×N_SF，

N_dl-PRB＝N_dl-RB×N_SF，

Wherein N is_ul-RBConfiguring a parameter, N, for the uplink transmission bandwidth_dl-RBConfiguring a parameter, N, for the downlink transmission bandwidth_SFIs the number of subframes within a radio frame.

3. The method of claim 1, wherein the calculating the number of resource blocks used by the accessed service in the cell comprises:

calculating the number N of resource blocks used by the accessed service uplink in the cell according to the following formula_ul-oAnd the number N of resource blocks used by the downlink of the accessed service in the cell_dl-o：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>ul</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>dl</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>,</mo></mrow></math>

Wherein R is_ul-tIs the sum of the uplink rates, R, of the accessed services in the cell_dl-tIs the sum of the downlink rates, R, of the accessed services in the cell_ul-aIs the actual average rate, R, of the uplink of the accessed service in the cell_dl-aIs the actual average downlink speed, lambda, of the accessed service in the cell_ul-CELLIs the cell uplink average retransmission rate, lambda_dl-CELLIs the cell downlink average retransmission rate, N_ul-aThe number of resource blocks occupied by each wireless frame is actually averaged for the uplink service in the accessed service in the cell, N_dl-aAnd actually averaging the number of resource blocks occupied by each wireless frame for the downlink service in the accessed service in the cell.

4. The method of claim 1, wherein the calculating the number of resource blocks required to be used for accessing the service comprises:

calculating the number N of resource blocks needed by the initial transmission of the uplink service of the service to be accessed according to the following formula_ul-iAnd the number N of resource blocks needed by the initial transmission of the downlink service of the service to be accessed_dl-i：

$N_{\mathrm{ul}-i}=\frac{B_{\mathrm{ul}-\mathrm{RF}}}{B_{\mathrm{ul}-\mathrm{PRB}}},$

$N_{\mathrm{dl}-i}=\frac{B_{\mathrm{dl}-\mathrm{RF}}}{B_{\mathrm{dl}-\mathrm{PRB}}},$

Wherein, B_ul-RFAnd B_dl-RFRespectively ensuring the uplink and downlink rates of a service to be accessed, the bit number of uplink transmission and the bit number of downlink transmission of a wireless frame; b is_ul-PRBAnd B_dl-PRBRespectively representing the uplink transmission bit number and the downlink transmission bit number of each resource block;

calculating the number N of resource blocks needed by the uplink service retransmission of the service to be accessed according to the following formula_ul-rAnd the number N of resource blocks needed by the retransmission of the downlink service of the service to be accessed_dl-r：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>ul</mi></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>dl</mi></msub><mo>,</mo></mrow></math>

Wherein λ is_ulFor the uplink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switching user, the λ_ulTaking the average retransmission rate lambda of the cell uplink_ul-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_ulAverage retransmission rate lambda of user uplink_ul-UE；λ_dlFor the downlink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switched user, the λ_dlTaking the average downlink retransmission rate lambda of the cell_dl-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_dlUser downlink average retransmission rate lambda_dl-UE；

Finally, the calculation is carried out according to the following formula:

ΔN_ul＝N_ul-i+N_ul-r，

ΔN_dl＝N_dl-i+N_dl-r，

wherein, Δ N_ulNumber of resources, Δ N, required for uplink transmission of a service to be accessed_dlThe number of resources required for downlink transmission of the service to be accessed.

5. The method according to any one of claims 1 to 4, wherein the determining whether the service to be accessed can access the cell according to the total number of resource blocks of the cell, the number of resource blocks used by the accessed service in the cell, and the number of resource blocks required to be used by the service to be accessed comprises:

when the sum of the number of resource blocks used by the uplink of the accessed service and the number of resource blocks required by the uplink transmission of the service to be accessed in the cell is less than the total number of uplink resource blocks of the cell, and the sum of the number of resource blocks used by the downlink of the accessed service and the number of resource blocks required by the downlink transmission of the service to be accessed in the cell is less than the total number of downlink resource blocks of the cell, allowing the service to be accessed to the cell, or else rejecting the service to be accessed to the cell;

or,

when the sum of the number of resource blocks used by the accessed service uplink in the cell and the number of resource blocks required by the uplink transmission of the service to be accessed is smaller than the total number of resource blocks in the cell multiplied by a preset coefficient, and the sum of the number of resource blocks used by the accessed service downlink in the cell and the number of resource blocks required by the downlink transmission of the service to be accessed is smaller than the total number of resource blocks in the cell multiplied by the preset coefficient, the service to be accessed is allowed to be accessed to the cell, otherwise, the service to be accessed is refused to be accessed to the cell.

6. A radio access control apparatus in an LTE access system, the apparatus comprising: the device comprises a total resource calculation module, a used resource calculation module, a to-be-used resource calculation module and an access judgment module, wherein:

the total resource calculation module is used for calculating the total resource block number of the cell and sending the total resource block number to the access judgment module;

the used resource calculation module is used for calculating the number of resource blocks used by the accessed service in the cell and sending the resource blocks to the access judgment module;

the resource to be used calculation module is used for calculating the number of resource blocks required to be used by the service to be accessed and sending the number of the resource blocks to the access judgment module;

and the access judging module is used for judging whether the service to be accessed can be accessed into the cell or not according to the total number of the resource blocks of the cell, the number of the resource blocks used by the accessed service in the cell and the number of the resource blocks needed to be used by the service to be accessed, if so, the service to be accessed is allowed to be accessed into the cell, otherwise, the service to be accessed is refused to be accessed into the cell.

7. The apparatus of claim 6, further comprising: a parameter acquisition module;

the parameter obtaining module is used for obtaining a transmission bandwidth configuration parameter N in a TDD mode_RBAn uplink subframe number N in a radio frame_ul-SFAnd a downlink subframe number N in a radio frame_dl-SFAnd sending the data to the total resource calculation module; in FDD mode, the method is used for obtaining the configuration parameter N of the uplink transmission bandwidth_ul-RBDownlink transmission bandwidth configuration parameter N_dl-RBAnd the number of subframes N within one radio frame_SFAnd sending the data to the total resource calculation module;

the total resource calculating module is used for calculating the total uplink resource block number N of the cell by the following formula_ul-PRBAnd the total downlink resource block number N of the cell_dl-PRB：

For the TDD mode, the transmission rate is,

N_ul-PRB＝N_RB×N_ul-SF，

N_dl-PRB＝N_RB×N_dl-SF，

for the case of the FDD mode,

N_ul-PRB＝N_ul-RB×N_SF，

N_dl-PRB＝N_dl-RB×N_SF。

8. the apparatus of claim 6, further comprising a measurement module;

the measuring module is used for measuring the actual average uplink rate R of the accessed service in the cell_ul-aActual downlink average rate R of accessed service in cell_dl-aCell uplink average retransmission rate lambda_ul-CELLCell downlink average retransmission rate lambda_dl-CELLThe number N of resource blocks occupied by each wireless frame is actually averaged by the uplink service in the accessed service in the cell_ul-aAnd the number N of resource blocks occupied by each radio frame is actually averaged by the downlink service in the accessed service in the cell_dl-aAnd sending the parameters to a used resource calculation module;

the used resourceA calculating module, configured to obtain an uplink rate sum R of accessed services in the cell from the context of the cell_ul-tAnd the sum R of the downlink rates of the accessed services in the cell_dl-tAnd calculating the number N of resource blocks used by the accessed service uplink in the cell according to the following formula_ul-oAnd the number N of resource blocks used by the downlink of the accessed service in the cell_dl-o：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>ul</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>o</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>t</mi></mrow></msub><mrow><msub><mi>R</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>/</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>&lambda;</mi><mrow><mi>dl</mi><mo>-</mo><mi>CELL</mi></mrow></msub><mo>)</mo></mrow></mrow></mfrac><mo>&times;</mo><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>a</mi></mrow></msub><mo>.</mo></mrow></math>

9. The apparatus of claim 6, further comprising: a measurement module;

the measurement module is used for measuring the cell uplink average retransmission rate lambda_ul-CELLCell downlink average retransmission rate lambda_dl-CELLUser uplink average retransmission rate lambda_ul-UEUser downlink average retransmission rateλ_dl-UECell uplink average modulation and coding scheme MCS_ul-CELLCell downlink average modulation and coding scheme MCS_dl-CELLUser uplink average modulation and coding scheme MCS_ul-UEAnd user downlink average modulation and coding scheme MCS_dl-UEAnd sending the data to a resource calculation module to be used;

a module for calculating resources to be used, when the service to be accessed is the first bearer of the user or the bearer of the switched user, the module is used for calculating the resources to be used according to the MCS_ul-CELLObtaining the bit number B of uplink transmission of each resource block_ul-PRBAccording to MCS_dl-CELLObtaining the bit number B of downlink transmission of each resource block_dl-PRB(ii) a When the service to be accessed is a load initiated after the on-line user, the method is used for carrying out the load according to the MCS_ul-UEObtaining the bit number B of uplink transmission of each resource block_ul-PRBAccording to MCS_dl-UEObtaining the bit number B of downlink transmission of each resource block_dl-PRB(ii) a Used for obtaining the bit number B of a wireless frame uplink transmission for ensuring the uplink and downlink rates of the service to be accessed according to the uplink guaranteed rate of the service to be accessed_ul-RFAnd bit number B of downlink transmission_dl-RF；

A resource to be used calculating module for calculating the number N of resource blocks needed by the initial transmission of the uplink service of the service to be accessed according to the following formula_ul-iAnd the number N of resource blocks needed by the initial transmission of the downlink service of the service to be accessed_dl-i：

$N_{\mathrm{ul}-i}=\frac{B_{\mathrm{ul}-\mathrm{RF}}}{B_{\mathrm{ul}-\mathrm{PRB}}},$

$N_{\mathrm{dl}-i}=\frac{B_{\mathrm{dl}-\mathrm{RF}}}{B_{\mathrm{dl}-\mathrm{PRB}}},$

A resource to be used calculation module for calculating the number N of resource blocks needed by the uplink service retransmission of the service to be accessed according to the following formula_ul-rAnd the number N of resource blocks needed by the retransmission of the downlink service of the service to be accessed_dl-r：

<math><mrow><msub><mi>N</mi><mrow><mi>ul</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>ul</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>ul</mi></msub><mo>,</mo></mrow></math>

<math><mrow><msub><mi>N</mi><mrow><mi>dl</mi><mo>-</mo><mi>r</mi></mrow></msub><mo>=</mo><mfrac><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>RF</mi></mrow></msub><msub><mi>B</mi><mrow><mi>dl</mi><mo>-</mo><mi>PRB</mi></mrow></msub></mfrac><mo>&times;</mo><msub><mi>&lambda;</mi><mi>dl</mi></msub><mo>,</mo></mrow></math>

Wherein λ is_ulFor the uplink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switching user, the λ_ulTaking the average retransmission rate lambda of the cell uplink_ul-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_ulAverage retransmission rate lambda of user uplink_ul-UE；λ_dlFor the downlink retransmission rate, when the service to be accessed is the first bearer of the user or the bearer of the switched user, the λ_dlTaking the average downlink retransmission rate lambda of the cell_dl-CELLLambda is when the service to be accessed is the load-bearing initiated after the on-line user_dlUser downlink average retransmission rate lambda_dl-UE；

And finally, a resource to be used calculation module for calculating the number of resources delta N required by the uplink transmission of the service to be accessed according to the following formula_ulAnd the number of resources delta N required for downlink transmission of the service to be accessed_dl：

ΔN_ul＝N_ul-i+N_ul-r，

ΔN_dl＝N_dl-i+N_dl-r。

10. The apparatus according to any one of claims 6 to 9,

the access judging module is used for allowing the service to be accessed to the cell when the sum of the number of resource blocks used by the uplink of the accessed service and the number of resource blocks required by the uplink transmission of the service to be accessed in the cell is less than the total number of uplink resource blocks of the cell, and the sum of the number of resource blocks used by the downlink of the accessed service and the number of resource blocks required by the downlink transmission of the service to be accessed in the cell is less than the total number of downlink resource blocks of the cell, otherwise, refusing the service to be accessed to the cell;

or,

the access judging module is used for allowing the service to be accessed to the cell when the sum of the number of resource blocks used by the uplink of the accessed service and the number of resource blocks required by the uplink transmission of the service to be accessed in the cell is smaller than the sum of the number of uplink total resource blocks of the cell multiplied by a preset coefficient, and the sum of the number of resource blocks used by the downlink of the accessed service and the number of resource blocks required by the downlink transmission of the service to be accessed in the cell is smaller than the sum of downlink total resource blocks of the cell multiplied by the preset coefficient, otherwise, the service to be accessed is refused to be accessed to the cell.

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