Method and apparatus for performing cell reselection in wireless communication system
A method of operating a terminal and a base station in a wireless communication system and an apparatus supporting the same are disclosed. The method comprises receiving a first system information block (SIB) from a first base station—the received first SIB including at least one first parameter for a cell reselection learning model—, receiving radio channel environment information from the first base station, updating the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information, and performing cell reselection for a second base station based on the updated at least one second parameter.
1 . A method comprising:
receiving, by a terminal, a first system information block (SIB) from a first base station, the first SIB including at least one first parameter;
receiving, by the terminal, first information from the first base station;
receiving information related to a weight from the first base station; and
performing, by the terminal, a cell reselection for a second base station based on at least one second parameter,
wherein the at least one first parameter is updated to the at least one second parameter using a cell reselection learning model,
wherein the first information and the at least one first parameter are inputted to a cell reselection learning model to update the at least one first parameter to the at least one second parameter,
wherein the weight is a value for minimizing a difference between a value measured by the first base station and the at least one first parameter, and
wherein, when updating the at least one first parameter to the at least one second parameter, the weight is further considered.
2 . The method of claim 1 ,
wherein the at least one first parameter is generated by the first base station,
wherein the first base station receives parameter information related to the cell reselection learning model from a plurality of terminals, and
wherein the at least one first parameter is generated based on the parameter information related to the cell reselection learning model received from the plurality of terminals and is transmitted to the terminal through the first SIB.
3 . The method of claim 1 ,
wherein the at least one second parameter is transmitted to the second base station,
wherein, based on the at least one second parameter, cell reselection related information is received through a second SIB from the second base station,
wherein the cell reselection for the second base station is performed based on the cell reselection related information, and
wherein the cell reselection related information is generated by the second base station based on the at least one second parameter.
4 . The method of claim 3 , wherein the at least one second parameter is transmitted to the second base station through a random access channel (RACH).
5 . The method of claim 1 , wherein the first information comprises information related to a channel state.
6 . The method of claim 1 , further comprises receiving information indicating whether to use the cell reselection learning model from the first base station.
7 . The method of claim 6 , wherein the terminal updates the at least one second parameter only when the information indicating whether to use the cell reselection learning model indicates that the cell reselection learning model is used.
8 . The method of claim 1 , wherein the cell reselection learning model is a model trained based on a beta distribution.
9 . The method of claim 8 , wherein the reselecting the second base station based on the at least one second parameter comprises reselecting the second base station based on a maximum value of values obtained by randomly sampling the beta distribution.
10 . The method of claim 9 ,
wherein parameters of the beta distribution are α and β, and
wherein an α+1 operation is performed on the parameters of the beta distribution based on a receive power of the terminal being maintained or being increased after cell reselection, and
wherein a β+1 operation is performed on the parameters of the beta distribution based on the receive power being decreased after cell reselection.
11 . The method of claim 10 , further comprising:
updating the beta distribution based on the β+1 operation; and
transmitting the at least one second parameter, on which the β+1 operation is performed, to the second base station.
12 . An apparatus comprising:
a wireless transceiver; and
a processor,
wherein the processor is configured to:
control the wireless transceiver to receive a first system information block (SIB) from a first base station, the received first SIB including at least one first parameter,
control the wireless transceiver to receive a first information from the first base station,
control the wireless transceiver to receive information related to a weight from the first base station, and
perform a cell reselection for a second base station based on at least one second parameter,
wherein the at least one first parameter is updated to the at least one second parameter using cell reselection learning model,
wherein the first information and the at least one first parameter are inputted to a cell reselection learning model to update the at least one first parameter to the at least one second parameter,
wherein the weight is a value for minimizing a difference between a value measured by the first base station and the at least one first parameter, and
wherein, when updating the at least one first parameter to the at least one second parameter, the weight is further considered.
13 . The apparatus of claim 12 ,
wherein the at least one first parameter is generated by the first base station,
wherein the first base station receives parameter information related to the cell reselection learning model from a plurality of terminals, and
wherein the at least one first parameter is generated based on the parameter information related to the cell reselection learning model received from the plurality of terminals and is transmitted using the wireless transceiver through the first SIB.
14 . The apparatus of claim 12 ,
wherein the processor is further configured to:
control the wireless transceiver to transmit at least one second parameter to the second base station, and
control the wireless transceiver to receive, through a second SIB, cell reselection related information generated by the second base station based on the second parameter, and
perform the cell reselection for the second base station based on the cell reselection related information included in the received second SIB.
15 . A base station comprising:
a wireless transceiver; and
a processor connected to the wireless transceiver,
wherein the processor is configured to:
control the wireless transceiver to transmit a system information block (SIB) including at least one first parameter to a first terminal,
control the wireless transceiver to transmit a first information to the first terminal, and
control the wireless transceiver to transmit information related to a weight to the first terminal,
wherein the at least one first parameter is generated based on parameter information related to a cell reselection model received from a plurality of terminals,
wherein the first information and the at least one first parameter are used by the cell reselection model by the first terminal to update the at least one first parameter to at least one second parameter,
wherein the weight is a value for minimizing a difference between a value measured by the first base station and the at least one first parameter, and
wherein, when updating the at least one first parameter to the at least one second parameter, the weight is further considered.
16 . The apparatus of claim 12 , wherein the at least one second parameter is transmitted to the second base station through a random access channel (RACH).
17 . The apparatus of claim 12 , wherein the first information comprises information related to a channel state.
18 . The apparatus of claim 12 , wherein the processor is further configured to:
control the wireless transceiver to receive an information indicating whether to use the cell reselection learning model from the first base station, and
update the at least one second parameter only when the information indicating whether to use the cell reselection learning model indicates that the cell reselection learning model is to be used.