Hard handover method, controller and communication system

Abstract

The invention is related to a controller of a communication system, the controller comprising: means for determining user terminal time delay between delivery and acknowledgement of a transmission; means for conveying the user terminal time delay; means for calculating switching time delay; and means for transferring user terminal data conveyance to the handover target network controller at a moment based on the switching time delay.

1 . A method, comprising:
 determining user terminal time delay between delivery and acknowledgement of a transmission, in a handover source network controller;   conveying the user terminal time delay to a handover target network controller; and   transferring user terminal data conveyance to the handover target network controller based on the switching time delay.   
   
   
       2 . The method of  claim 1 , further comprising:
 calculating a switching time delay in the handover target network controller.   
   
   
       3 . The method of  claim 2 , wherein the switching time delay is calculated by using an equation comprising, 
     
       
         
           
             
               
                 
                   round 
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                   trip 
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                   time 
                 
                 2 
               
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                 UE 
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                 cell 
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                 changeover 
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                 time 
               
             
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     wherein the UE corresponds to a user terminal or a user equipment, and the UE cell changeover time is a previously known parameter or is estimated during an intra-RNC hard handover, where a round-trip time is measured during a configuration management and subtracted from the switching time delay caused by the hard handover target network controller. 
   
   
       4 . The method of  claim 1 , wherein the conveying comprises conveying by adding a new field to a container that is passed to the handover target network controller during an inter-RNC hard handover. 
   
   
       5 . An apparatus, comprising:
 a determiner configured to determine user terminal time delay between delivery and acknowledgement of a transmission;   a conveyer configured to convey and receiving the user terminal time delay; and   a transferor configured to transfer user terminal data conveyance to a handover target network controller based on the switching time delay.   
   
   
       6 . The apparatus of  claim 5 , further comprising:
 calculator configured to calculate a switching time delay.   
   
   
       7 . The apparatus of  claim 6 , wherein the calculator is configured to calculate the switching time delay by using an equation comprising 
     
       
         
           
             
               
                 
                   round 
                    
                   
                     - 
                   
                    
                   trip 
                    
                   
                       
                   
                    
                   time 
                 
                 2 
               
               + 
               
                 UE 
                  
                 
                     
                 
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                 cell 
                  
                 
                     
                 
                  
                 changeover 
                  
                 
                     
                 
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                 time 
               
             
             , 
           
         
       
     
     wherein the UE corresponds to a user terminal or a user equipment, and the UE cell changeover time is a previously known parameter or is estimated during an intra-RNC hard handover, where a round-trip time is measured during a configuration management and subtracted from the switching time delay caused by the hard handover target network controller. 
   
   
       8 . The apparatus of  claim 6 , wherein the calculator is further configured to calculate the switching time delay using user terminal cell changeover time and the user terminal time delay between the delivery and the acknowledgement of the transmission. 
   
   
       9 . The apparatus of  claim 5 , wherein the conveyer is further configured to receive the user terminal time delay. 
   
   
       10 . The apparatus of  claim 5 , wherein the conveyer is configured to convey the user terminal time delay by adding a new field to a container that is passed to the handover target network controller during an inter-radio network controller hard handover. 
   
   
       11 . The apparatus of  claim 5 , wherein the determiner is further configured to determine a round-trip time as the user terminal time delay between the delivery and the acknowledgement of the transmission. 
   
   
       12 . The apparatus of  claim 5 , further comprising:
 a controller configured to control the switching time delay by delaying sending of a relocation detect message from a target radio network controller (RNC).   
   
   
       13 . A computer program embodied on a computer-readable medium, the computer program configured to control a processor to perform operations comprising:
 determining user terminal time delay between delivery and acknowledgement of a transmission, in a handover source network controller;   conveying the user terminal time delay to a handover target network controller; and   transferring user terminal data conveyance to the handover target network controller based on the switching time delay.   
   
   
       14 . A system, comprising:
 a controller configured to,
 determine user terminal time delay between delivery and acknowledgement of a transmission; 
 convey the user terminal time delay; 
 calculate a switching time delay; and 
 transfer user terminal data conveyance to a handover target network controller based on the switching time delay. 
   
   
   
       15 . A method, comprising:
 receiving a user terminal time delay from a handover source network controller;   calculating a switching time delay in the handover target network controller using the user terminal time delay; and   transferring a user terminal data conveyance to the handover target network controller based on the switching time delay.   
   
   
       16 . The method of  claim 15 , wherein the switching time delay is calculated using user terminal cell changeover time and the user terminal time delay between the delivery and the acknowledgement of the transmission. 
   
   
       17 . The method of  claim 15 , wherein a round-trip time is determined as the user terminal time delay between the delivery and the acknowledgement of the transmission. 
   
   
       18 . The method of  claim 15 , wherein the switching time delay is controlled by delaying sending of a relocation detect message from a target radio network controller. 
   
   
       19 . An apparatus, comprising:
 a receiver configured to receive a user terminal time delay from a handover source network controller;   a calculator configured to calculate a switching time delay in the handover target network controller using the user terminal time delay; and   a transferor configured to transfer a user terminal data conveyance to the handover target network controller based on the switching time delay.   
   
   
       20 . The apparatus of  claim 19 , the calculator is configured to calculate the switching time delay using a user terminal cell changeover time and the user terminal time delay between the delivery and the acknowledgement of the transmission. 
   
   
       21 . The apparatus of  claim 19 , wherein a round-trip time is determined as the user terminal time delay between the delivery and the acknowledgement of the transmission. 
   
   
       22 . The apparatus of  claim 19 , wherein the switching time delay is controlled by delaying sending of a relocation detect message from a target radio network controller. 
   
   
       23 . A computer program embodied on a computer-readable medium, the computer program configured to control a processor to perform operations comprising:
 receiving a user terminal time delay from a handover source network controller;   calculating a switching time delay in the handover target network controller using the user terminal time delay; and transferring a user terminal data conveyance to the handover target network controller based on the switching time delay.