# US 2018/0324656 A1 · Cell reselection method and appratus

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- Number: US 2018/0324656 A1
- Document ID: US20180324656A1
- Status: Published application
- Kind: A1
- Application number: 15/772,095
- Filed: 2016-09-06
- Published: 2018-11-08
- Earliest claimed: 2015-11-03
- Assignees: China Mobile Communications Group Co., Ltd.
- Applicants: China Mobile Communications Group Co., Ltd.
- Inventors: Ningyu Chen; Zhuo Chen; Nan Hu
- Web page: https://patentgrep.com/patent/US20180324656A1

## CPC

- H04W 36/08: Reselecting an access point
- H04W 36/00837: {Determination of triggering parameters for hand-off}
- H04W 36/302: {due to low signal strength}
- H04W 48/02: Access restriction performed under specific conditions
- H04W 48/20: Selecting an access point
- H04W 48/12: using downlink control channel
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

The present disclosure provides a cell reselection method and apparatus. The cell reselection method comprises: after a terminal sends a first access request or the first access request is blocked for preset times, separately obtaining a first block parameter of a serving cell and a second block parameter of a neighboring cell of the serving cell, the first access request being an access request for a target service or application; generating offset parameter information corresponding to the target service or application according to the first block parameter and the second block parameter, the offset parameter information comprising: information about first duration for which the target service or application needs to wait to access the serving cell and information about second duration for which the target service or application needs to wait to access the neighboring cell; and applying the offset parameter information to a cell reselection rule R, and determining a target cell to camp on.

## Claims

### Claim 1

A cell reselection method, applied to User Equipment (UE), wherein the cell reselection method comprises:
after the UE sends a first access request or the first access request is barred for a predetermined number of times, acquiring a first barring parameter of a serving cell and a second barring parameter of a neighbor cell of the serving cell, the first access request being a request for accessing a target service or application;
generating offset parameter information corresponding to the target service or application according to the first barring parameter and the second barring parameter, the offset parameter information comprising: first time information indicating a time period for which the target service or application is required to wait for access to the serving cell and second time information indicating a time period for which the target service or application is required to wait for access to the neighbor cell; and
applying the offset parameter information to a cell reselection R criterion, and determining a target cell for camping on.

### Claim 2 (depends on 1)

The cell reselection method according to claim 1, after applying the offset parameter information to the cell reselection R criterion and determining the target cell for camping on, the cell reselection method further comprising:
judging whether a second access request for the target service or application is sent or not within a first predetermined time after camping on the target cell;
if the second access request is sent within the first predetermined time and no access request for the target service or application is sent within a second predetermined time after finishing an indication operation corresponding to the second access request, determining that the offset parameter information gets invalid; and
if the second access request is not sent within the first predetermined time, determining that the offset parameter information gets invalid.

### Claim 3 (depends on 1)

The cell reselection method according to claim 1, wherein acquiring the second barring parameter of the neighbor cell of the serving cell comprises:
receiving the second barring parameter, broadcast by the serving cell, of the neighbor cell, wherein the second barring parameter is an access control barring parameter of the neighbor cell; or,
acquiring a Master Information Block (MIB) message of the neighbor cell, and performing analysis and processing on a System Information Block (SIB) message according to the MIB message to obtain the second barring parameter of the neighbor cell, wherein the second barring parameter is the access control barring parameter of the neighbor cell.

### Claim 4 (depends on 1)

The cell reselection method according to claim 1, wherein generating the offset parameter information corresponding to the target service or application according to the first barring parameter and the second barring parameter comprises:
acquiring a first access control class corresponding to the target service or application in the serving cell and a second access control class corresponding to the target service or application in the neighbor cell;
taking a barring parameter in the first access control class as the first barring parameter, wherein information of the first barring parameter comprises: a barring probability Pbars of the serving cell and a barring time Tbars of the serving cell;
taking a barring parameter in the second access control class as the second barring parameter, wherein information of the second barring parameter comprises: a barring probability Pbarn of the neighbor cell and a barring time Tbarn of the neighbor cell; and
generating the offset parameter information through formulae QACDC,s=α×(1−Pbars)×Tbars and QACDC,n=α×(1−Pbarn)×Tbarn, α representing a preset adjustment parameter, QACDC,s representing the first time information and QACDC,n representing the second time information.

### Claim 5 (depends on 1)

The cell reselection method according to claim 1, wherein generating the offset parameter information corresponding to the target service or application according to the first barring parameter and the second barring parameter comprises:
acquiring barring parameters in all access control classes of the serving cell, and taking the barring parameters in all the access control classes of the serving cell as the first barring parameter;
acquiring barring parameters in all access control classes of the neighbor cell, and taking the barring parameters in all the access control classes of the neighbor cell as the second barring parameter;
generating the first time information through a formula QACDC, s=α1×(1−Pbar1)×Tbar1+α2×(1−Pbar2)×Tbar2+ . . . +αn×(1−Pbarn)×Tbarn, where QACDC,s represents the first time information, Pbarn represents a barring probability of the nth access control class of the serving cell, Tbarn represents a barring time of the nth access control class of the serving cell, and αn represents a weighted value of the nth access control class of the serving cell; and
generating the second time information through a formula QACDC, n=α1×(1−Pbar1)×Tbar1+α2×(1−Pbar2)×Tbar2+ . . . +αi×(1−Pbari)×Tbari, where QACDC,n represents the second time information, Pbari represents a barring probability of the ith access control class of the neighbor cell, Tbari represents a barring time of the ith access control class of the neighbor cell, and αi represents a weighted value of the ith access control class of the neighbor cell.

### Claim 6 (depends on 4)

The cell reselection method according to claim 4, wherein applying the offset parameter information to the cell reselection R criterion and determining the target cell for camping on comprises:
acquiring a value of R of the serving cell through a formula Rs=Qmeas,s+QHyst−Qoffsettemp−QACDC,s where Rs represents the value of R of the serving cell, Qmean,s represents Reference Signal Receiving Power (RSRP) for cell reselection, QHyst represents a reselection hysteresis parameter of the serving cell, Qoffsettemp represents a new offset parameter in the cell reselection R criterion, and QACDC,s represents the first time information;
acquiring a value of R of the neighbor cell through a formula Rn=Qmeas,n−Qoffset−Qoffsettemp−QACDC,n, where Rn represents the value of R of the neighbor cell, Qmean,n represents the RSRP for cell reselection, Qoffset represents an offset value of the neighbor cell, Qoffsettemp represents the new offset parameter in the cell reselection R criterion, and QACDC,n represents the second time information; and
selecting a cell with a maximum value of R from the serving cell and the neighbor cell as the target cell.

### Claim 7

A cell reselection device, applied to User Equipment (UE), wherein the cell reselection device comprises:
an acquisition module, configured to, after the UE sends a first access request or the first access request is barred for a predetermined number of times, acquire a first barring parameter of a serving cell and a second barring parameter of a neighbor cell of the serving cell, the first access request being a request for accessing a target service or application;
a generation module, configured to generate offset parameter information corresponding to the target service or application according to the first barring parameter and the second barring parameter, the offset parameter information comprising: first time information indicating a time period for which the target service or application is required to wait for access to the serving cell and second time information indicating a time period for which the target service or application is required to wait for access to the neighbor cell; and
a first determination module, configured to apply the offset parameter information to a cell reselection R criterion and determine a target cell for camping on.

### Claim 8 (depends on 7)

The cell reselection device according to claim 7, further comprising:
a judgment module, configured to judge whether a second access request for the target service or application is sent or not within a first predetermined time after camping on the target cell;
a second determination module, configured to, if the second access request is sent within the first predetermined time and no access request for the target service or application is sent within a second predetermined time after finishing an indication operation corresponding to the second access request, determine that the offset parameter information gets invalid; and
a third determination module, configured to, if the second access request is not sent within the first predetermined time, determine that the offset parameter information gets invalid.

### Claim 9 (depends on 7)

The cell reselection device according to claim 7, wherein the acquisition module comprises:
a receiving unit, configured to receive the second barring parameter, broadcast by the serving cell, of the neighbor cell, wherein the second barring parameter is an access control barring parameter of the neighbor cell; or,
a first acquisition unit, configured to acquire a Master Information Block (MIB) message of the neighbor cell, and perform analysis and processing on a System Information Block (SIB) message according to the MIB message to obtain the second barring parameter of the neighbor cell, wherein the second barring parameter is the access control barring parameter of the neighbor cell.

### Claim 10 (depends on 7)

The cell reselection device according to claim 7, wherein the generation module comprises:
a second acquisition unit, configured to acquire first access control class corresponding to the target service or application in the serving cell and a second access control class corresponding to the target service or application in the neighbor cell;
a first processing unit, configured to take a barring parameter in the first access control class as the first barring parameter, wherein information of the first barring parameter comprises: a barring probability Pbars of the serving cell and a barring time Tbars of the serving cell;
a second processing unit, configured to take a barring parameter in the second access control class as the second barring parameter, wherein information of the second barring parameter comprises: a barring probability Pbarn of the neighbor cell and a barring time Tbarn of the neighbor cell; and
a first generation unit, configured to generate the offset parameter information through formulae QACDC,s=α×(1−Pbars)×Tbars and QACDC,n=α×(1−Pbarn)×Tbarn, α representing a preset adjustment parameter, QACDC,s representing the first time information and QACDC,n representing the second time information.

### Claim 11 (depends on 7)

The cell reselection device according to claim 7, wherein the generation module further comprises:
a third acquisition unit, configured to acquire barring parameters in all access control classes of the serving cell, and take the barring parameters in all the access control classes of the serving cell as the first barring parameter;
a fourth acquisition unit, configured to acquire barring parameters in all access control classes of the neighbor cell, and take the barring parameters in all the access control classes of the neighbor cell as the second barring parameter;
a second generation unit, configured to generate the first time information through a formula QACDC, s=α1×(1−Pbar1)×Tbar1+α2×(1−Pbar2)×Tbar2+ . . . +αn×(1−Pbarn)×Tbarn, where QACDC,s represents the first time information, Pbarn represents a barring probability of the nth access control class of the serving cell, Tbarn represents a barring time of the nth access control class of the serving cell, and αn represents a weighted value of the nth access control class of the serving cell; and
a third generation unit, configured to generate the second time information through a formula QACDC, n=α1×(1−Pbar1)×Tbar1+α2×(1−Pbar2)×Tbar2+ . . . +αi×(1−Pbari)×Tbari, where QACDC,n represents the second time information, Pbari represents a barring probability of the ith access control class of the neighbor cell, Tbari represents a barring time of the ith access control class of the neighbor cell, and αi represents a weighted value of the ith access control class of the neighbor cell.

### Claim 12 (depends on 10)

The cell reselection device according to claim 10, wherein the first determination module comprises:
a fifth acquisition unit, configured to acquire a value of R of the serving cell through a formula Rs=Qmeas,s+QHyst−Qoffsettemp−QACDC,s, where Rs represents the value of R of the serving cell, Qmean,s represents Reference Signal Receiving Power (RSRP) for cell reselection, QHyst represents a reselection hysteresis parameter of the serving cell, Qoffsettemp represents a new offset parameter in the cell reselection R criterion, and QACDC,s represents the first time information;
a sixth acquisition unit, configured to acquire a value of R of the neighbor cell through a formula Rn=Qmeas,n−Qoffset−Qoffsettemp−QACDC,n, where Rn represents the value of R of the neighbor cell, Qmean,n represents the RSRP for cell reselection, Qoffset represents an offset value of the neighbor cell, Qoffsettemp represents the new offset parameter in the cell reselection R criterion, and QACDC,n represents the second time information; and
a determination unit, configured to select a cell with a maximum value of R from the serving cell and the neighbor cell as the target cell.

### Claim 13 (depends on 5)

The cell reselection method according to claim 5, wherein applying the offset parameter information to the cell reselection R criterion and determining the target cell for camping on comprises:
acquiring a value of R of the serving cell through a formula Rs=Qmeas,s+QHyst−Qoffsettemp−QACDC,s, where Rs represents the value of R of the serving cell, Qmean,s represents Reference Signal Receiving Power (RSRP) for cell reselection, QHyst represents a reselection hysteresis parameter of the serving cell, Qoffsettemp represents a new offset parameter in the cell reselection R criterion, and QACDC,s represents the first time information;
acquiring a value of R of the neighbor cell through a formula Rn=Qmeas,n−Qoffset−Qoffsettemp−QACDC,n, where Rn represents the value of R of the neighbor cell, Qmean,n represents the RSRP for cell reselection, Qoffset represents an offset value of the neighbor cell, Qoffsettemp represents the new offset parameter in the cell reselection R criterion, and QACDC,n represents the second time information; and
selecting a cell with a maximum value of R from the serving cell and the neighbor cell as the target cell.

### Claim 14 (depends on 11)

The cell reselection device according to claim 11, wherein the first determination module comprises:
a fifth acquisition unit, configured to acquire a value of R of the serving cell through a formula Rs=Qmeas,s+QHyst−Qoffsettemp−QACDC,s, where Rs represents the value of R of the serving cell, Qmean,s represents Reference Signal Receiving Power (RSRP) for cell reselection, QHyst represents a reselection hysteresis parameter of the serving cell, Qoffsettemp represents a new offset parameter in the cell reselection R criterion, and QACDC,s represents the first time information;
a sixth acquisition unit, configured to acquire a value of R of the neighbor cell through a formula Rn=Qmeas,n−Qoffset−Qoffsettemp−QACDC,n, where Rn represents the value of R of the neighbor cell, Qmean,n represents the RSRP for cell reselection, Qoffset represents an offset value of the neighbor cell, Qoffsettemp represents the new offset parameter in the cell reselection R criterion, and QACDC,n represents the second time information; and
a determination unit, configured to select a cell with a maximum value of R from the serving cell and the neighbor cell as the target cell.