Handover method and control transfer method

Abstract

A handover method and a control transfer method are provided. A handover method of performing an inter-cell handover between a first ground station and a second ground station may include setting a first channel to the second ground station, measuring, by an airborne radio station, a second channel and reporting a measurement result to the first ground station, sending, by the first ground station, a handover request to at least one of a ground control station (GCS) or a control and non-payload communication (CNPC) network, determining, by the at least one of the GCS or the CNPC network, whether to perform a handover, and transmitting, by the at least one of the GCS or the CNPC network, a handover instruction to the airborne radio station based on a result of the determining.

What is claimed is: 
     
         1 . A control transfer method of performing a control transfer from a first ground control station (GCS) to a second GCS, the control transfer method comprising:
 setting a handover channel to a second ground station;   measuring a currently used channel and reporting a measurement result;   determining whether to perform a handover based on the measurement result;   sending a handover request to the first GCS based on whether to perform the handover;   determining, by the first GCS, whether to perform a control transfer in response to the handover request;   sending, by the first GCS, a control transfer request to the second GCS based on whether to perform the control transfer;   requesting, by the second GCS, the second ground station to prepare for a communication using the handover channel, in response to the control transfer request;   transmitting, by the first GCS, a handover instruction to an airborne radio station when the second GCS notifies the first GCS of a start of the control transfer; and   performing, by the airborne radio station, a handover to the handover channel in response to the handover instruction.   
     
     
         2 . The control transfer method of  claim 1 , wherein
 the measuring comprises measuring, by the airborne radio station, the currently used channel and reporting the measurement result to a first ground station, and   the determining of whether to perform the handover based on the measurement result comprises sending, by the first ground station, a handover request to the first GCS based on whether to perform the handover.   
     
     
         3 . The control transfer method of  claim 1 , wherein the measuring comprises measuring, by the second ground station, the currently used channel and reporting a measurement result to the second GCS. 
     
     
         4 . The control transfer method of  claim 1 , further comprising:
 sending, by the second GCS, a security setting information request to the airborne radio station; and   responding, by the airborne radio station, to the security setting information request.   
     
     
         5 . The control transfer method of  claim 4 , wherein
 the sending of the security setting information request comprises sending the security setting information request to the airborne radio station through the second ground station, and   the responding to the security setting information request comprises responding to the security setting information request through the second ground station.