Wireless communication method and device

Abstract

A wireless communication method and device are provided. The wireless communication method includes the steps of receiving a plurality of measurement results; determining whether a cell-change event is triggered according to the measurement results; calculating a reverse-direction criterion to determine whether a ping-pong effect will occur when the cell-change event is triggered; and terminating the cell-change event when the ping-pong effect will occur.

What is claimed is: 
     
         1 . A wireless communication method, comprising:
 receiving a plurality of measurement results;   determining whether a cell-change event is triggered according to the measurement results;   calculating a reverse-direction criterion to determine whether a ping-pong effect will occur when the cell-change event is triggered; and   terminating the cell-change event when the ping-pong effect will occur.   
     
     
         2 . The wireless communication method of  claim 1 , wherein the cell-change event is a cell reselection (CR) or a handover (HO). 
     
     
         3 . The wireless communication method of  claim 2 , further comprising:
 checking whether the reverse-direction criterion is satisfied according to stored system information or stored measurement parameter to determine whether the ping-pong effect will occur.   
     
     
         4 . The wireless communication method of  claim 2 , further comprising:
 removing a target cell or a target frequency for an evaluation from a candidate cell list for a time period when the reverse-direction criterion is satisfied.   
     
     
         5 . The wireless communication method of  claim 3 , wherein if the cell reselection is for inter radio access technology (IRAT), the method further comprises:
 performing an evaluation for the cell reselection in an evaluation phase before radio access technology (RAT) changes, wherein system information for a target cell is obtained in the evaluation phase.   
     
     
         6 . The wireless communication method of  claim 3 , further comprising:
 performing a cell global ID check or checks location information or history information to avoid physical cell identity (PCI) confusion.   
     
     
         7 . The wireless communication method of  claim 3 , further comprising:
 forbidding transmission of a measurement report for triggering the handover to a target cell when the reverse-direction criterion is satisfied.   
     
     
         8 . The wireless communication method of  claim 3 , further comprising:
 performing handover when the stored measurement parameters for the target cell cannot be obtained.   
     
     
         9 . The wireless communication method of  claim 1 , wherein if the cell-change event is for inter radio access technology (IRAT), the method further comprises:
 determining whether a current radio access technology is a preferred radio access technology and whether the current radio access technology has good signal quality; and   checking the reverse-direction criterion when the current radio access technology is the preferred radio access technology and the current radio access technology has good signal quality.   
     
     
         10 . The wireless communication method of  claim 9 , wherein when the current radio access technology is not the preferred radio access technology or the current radio access technology does not have good signal quality, the reverse-direction criterion will not be checked. 
     
     
         11 . The wireless communication method of  claim 1 , wherein if the cell-change event is for intra long term evolution (INTRA-LTE), the method further comprises:
 selecting a cell which has better signal strength to camp on when the ping-pong effect will occur.   
     
     
         12 . The wireless communication method of  claim 1 , further comprising:
 checking whether a multiple-cell ping-pong will occur according to cell-change history information and stored system information.   
     
     
         13 . A wireless communication device, comprising:
 a processor, configured to determine whether a cell-change event is triggered according to measurement results, and calculate a reverse-direction criterion to determine whether a ping-pong effect will occur when the cell-change event is triggered, wherein the processor terminates the cell-change event when the ping-pong effect will occur.   
     
     
         14 . The wireless communication device of  claim 13 , wherein the cell-change event is a cell reselection (CR) or a handover (HO). 
     
     
         15 . The wireless communication device of  claim 14 , wherein the processor further calculates whether the reverse-direction criterion is satisfied according to stored system information or stored measurement parameter to determine whether the ping-pong effect will occur. 
     
     
         16 . The wireless communication device of  claim 14 , wherein the processor further removes a target cell or a target frequency for an evaluation from a candidate cell list for a time period. 
     
     
         17 . The wireless communication device of  claim 15 , wherein if the cell reselection is for inter radio access technology (IRAT), the processor further performs an evaluation for the cell reselection in an evaluation phase before radio access technology (RAT) changes, wherein system information for a target cell is obtained in the evaluation phase. 
     
     
         18 . The wireless communication device of  claim 15 , wherein the processor further performs a cell global ID check or checks location information or history information to avoid physical cell identity (PCI) confusion. 
     
     
         19 . The wireless communication device of  claim 15 , wherein the processor further forbids the transmission of a measurement report for triggering the handover to technology target cell when the reverse-direction criterion is satisfied. 
     
     
         20 . The wireless communication device of  claim 15 , wherein the processor further performs handover when the stored measurement parameters for the target cell cannot be obtained. 
     
     
         21 . The wireless communication device of  claim 13 , wherein if the cell-change event is for inter radio access technology (IRAT), the processor further determines whether a current radio access technology is a preferred radio access technology and whether the current radio access technology has good signal quality, wherein when the current radio access technology is the preferred radio access technology and the current radio access technology has good signal quality, the processor checks the reverse-direction criterion. 
     
     
         22 . The wireless communication device of  claim 21 , wherein when the current radio access technology is not the preferred radio access technology or the current radio access technology does not have good signal quality, the processor will not check the reverse-direction criterion. 
     
     
         23 . The wireless communication device of  claim 13 , wherein if the cell-change event is for intra long term evolution (INTRA-LTE), the processor further selects a cell which has better signal strength to camp on. 
     
     
         24 . The wireless communication device of  claim 13 , wherein the processor further checks whether a multiple-cell ping-pong will occur according to cell-change history information and stored system information.