Penalty of cell reselection for a wireless device
AssigneeASUSTeK COMPUTER INC.
InventorRex Huan-Yueh Chen
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Abstract
An improved device and method for determining when to start a timer that applies a temporary offset to a signal quality measurement of a cell that is a candidate for reselection in a 3GPP Hierarchical Cell Structured wireless communications system. For a cell ranking criterion R, the timer is started to apply the temporary offset according to present invention rules that insure that the temporary offset is not applied until a candidate is eligible for reselection, preventing premature expiration of the timer and unintended cell reselection. A present invention mobile unit that uses the improved method includes a housing, a central processor, a timer for applying the temporary offset, and a memory. The memory includes computer code that applies the claimed invention rules for starting the timer.
Claims12
An improved method for serving cell reselection by a mobile unit in a Hierarchical Cell Structure (HCS) wireless communications system, each cell in the HCS wireless communications system having an assigned HCS priority, the mobile unit comprising a Radio Resource Control (RRC) used to establish at least a radio bearer for receiving system information transmitted from the serving cell to the mobile unit when the mobile unit is within a service area of the serving cell, the method comprising:
- if the HCS priority of the serving cell equals the HCS priority of a candidate cell, starting a timer after a measured signal quality of the candidate cell is greater than a sum of a measured signal quality of the serving cell plus a system information supplied offset between the serving cell and the candidate cell plus a system information specified hysteresis value for the serving cell to apply a temporary offset to obtain adjusted signal quality measurements of the candidate cell, the temporary offset being distinct from the system information supplied offset between the serving cell and the candidate cell, the system information specified hysteresis value for the serving cell, and the sum of both the system information supplied offset between the serving cell and the candidate cell and the system information specified hysteresis value for the serving cell, the adjusted signal quality measurements used for ranking that candidate cell for reselection;
- and
- completing cell reselection according to the adjusted measured signal quality of the candidate cell.
A mobile unit for use in a Hierarchical Cell Structure (HCS) wireless communications system, each cell in the HCS wireless communications system having an assigned HCS priority, the mobile unit in radio contact with a serving cell and capable of reselecting to a candidate cell, the serving cell broadcasting system information to be used by the mobile unit in a cell reselection process, the mobile unit comprising:
- a housing;
- a timer for applying a temporary offset to a signal quality measurement of the candidate cell for a predetermined time interval;
- a central processing unit for executing computer code;
- and
- a memory comprising:
- computer code for determining a quality measure for cell reselection setting in the serving cell;
- and
- improved computer code for starting a timer to apply a temporary offset to signal quality measurements of the candidate cell when the candidate cell qualifies for reselection, the temporary offset being distinct from the system information supplied offset between the serving cell and the candidate cell, the system information specified hysteresis value for the serving cell, and the sum of both the system information supplied offset between the serving cell and the candidate cell and the system information specified hysteresis value for the serving cell, the adjusted signal quality measurements used for ranking that candidate cell for reselection;
- wherein the improved computer code starts the timer if the HCS priority of the serving cell equals the HCS priority of the candidate cell and after the measured signal quality of the candidate cell is greater than the sum of a measured signal quality of the serving cell plus a system information supplied offset between the serving and the candidate cell plus a system information specified hysteresis value for the serving cell.
A method of ranking candidate cells during a cell reselection procedure in a Hierarchical Cell Structure (HCS) wireless communications system, each cell in the HCS wireless communications system having an assigned HCS priority, the wireless communications system comprising a mobile unit and a serving cell, the mobile unit having a Radio Resource Control (RRC) for establishing at least a radio bearer for receiving system information transmitted from the serving cell to the mobile unit when the mobile unit is within a service area of the serving cell, the method comprising:
- selecting candidate neighboring cells according to predetermined measurement rules using system information supplied thresholds;
- starting a timer in the mobile unit for application of a temporary offset adjusting signal quality measurements of a candidate cell after that candidate cell qualifies for reselection, the temporary offset being distinct from the system information supplied offset between the serving cell and the candidate cell, the system information specified hysteresis value for the serving cell, and the sum of both the system information supplied offset between the serving cell and the candidate cell and the system information specified hysteresis value for the serving cell;
- and
- ranking candidate cells according to the adjusted signal quality measurements for each candidate cell.
Dependencies are inferred from the claim text.