Signal Measurement on Component Carriers in Wireless Communication Systems

Abstract

A method in a wireless communication device includes performing measurements of a first serving cell on a first carrier frequency at a first rate, determining whether a signal level of a second serving cell on a second carrier frequency exceeds a threshold, and performing measurements of the first serving cell at a second rate if the signal level of the second serving cell is below the threshold, wherein the second rate is higher than the first rate.

1 . A method in a wireless communication device, the method comprising:
 performing measurements of a first serving cell on a first carrier frequency at a first rate;   determining whether a signal level of a second serving cell on a second carrier frequency is below a threshold; and   performing measurements of the first serving cell at a second rate if the signal level of the second serving cell is below the threshold, the second rate higher than the first rate.   
     
     
         2 . The method of  claim 1  further comprising reporting information based on at least some of the measurements to a first base station. 
     
     
         3 . The method of  claim 2 , wherein reporting information includes reporting information based on at least the measurements performed on the first serving cell at the second rate. 
     
     
         4 . The method of  claim 1  further comprising receiving a handover command from the first base station in response to sending the measurement report. 
     
     
         5 . The method of  claim 4  further comprising handing over to a second base station in a location different than the first base station in response to receiving the handover command. 
     
     
         6 . The method of  claim 4 , wherein the first serving cell on the first carrier frequency is a deactivated serving cell, the method further comprising configuring the first serving cell as a primary serving cell in response to receiving the handover command. 
     
     
         7 . The method of  claim 1 , wherein the wireless communication terminal is configured for carrier aggregation, and wherein the first carrier frequency is a deactivated carrier and wherein the second carrier frequency is a primary carrier frequency. 
     
     
         8 . The method of  claim 1  further comprising
 filtering the measurements performed on the first serving cell, 
 wherein reporting at least some of the measurements to the first base station includes reporting the filtered measurements. 
 
     
     
         9 . A method in a wireless communication base station, the method comprising:
 configuring a wireless communication terminal for carrier aggregation on a primary serving cell on a first carrier frequency and on a secondary serving cell on a second carrier frequency;   determining a secondary serving cell measurement threshold for measurements of the secondary serving cell when the secondary serving cell is deactivated;   signaling the secondary serving cell measurement threshold to the wireless communication terminal;   receiving a measurement report from the wireless communication terminal,   the measurement report based on measurements of the secondary serving cell on the second carrier frequency at a rate dependent on whether a signal measured on the primary serving cell is below the secondary serving cell measurement threshold;   signaling a handover command to the wireless communication terminal based on the measurement report.   
     
     
         10 . The method of  claim 9 , wherein the handover command signals the wireless communication terminal to hand over to a second base station in a location different than a location of the wireless communication base station. 
     
     
         12 . The method of  claim 9 , wherein the rate of measurements of the secondary serving cell on the second carrier frequency increase when the signal measured on the primary serving cell is below the secondary serving cell measurement threshold.