Method and apparatus for calculating location of terminal in wireless communication system
According to one embodiment of the present invention, a method for calculating the location of a terminal in a wireless communication system, which is to be performed by the terminal, comprises the steps of: transmitting, to a location server, a request for location estimation assist data for calculating the location of the terminal; receiving the location estimation assist data from the location server; and calculating the location of the terminal using the location estimation assist data. The location estimation assist data includes radio map information including a received signal strength (RSS) value from each access point collected at a plurality of location estimation reference points in a region having a predetermined range. The radio map includes information regarding the location estimation reference points (hereinafter, referred to as “update points”) which require an update of the radio map. The method may further include a step of determining whether or not an update of the location estimation assist data is required based on the calculated location of the terminal and the information regarding the update points.
1. A method for calculating a location of a terminal in a wireless communication system, the method being performed by the terminal and comprising:
transmitting a request for assistance data for calculating the location of the terminal to a location server;
receiving the assistance data from the location server; and
calculating the location of the terminal using the assistance data,
wherein the assistance data includes radio map information including a received signal strength (RSS) value from each of one or more access points, collected from multiple reference points within an area of a predetermined range, and information about update points for which an update of a radio map is necessary, and
determining whether update of the assistance data is needed based on the calculated location of the terminal and the information about the update points.
2. The method according to claim 1 , wherein the radio map information further includes:
an identifier of a radio map, a reference location of the radio map, indexes of the multiple reference points arranged in the radio map, and locations of the reference points.
3. The method according to claim 1 , wherein the radio map information further includes:
valid time information of the radio map information and valid geographic area information of the radio map information.
4. The method according to claim 1 , wherein determining whether an update of the assistance data is needed includes:
determining whether the calculated location of the terminal corresponds to the update points.
5. The method according to claim 4 , further comprising:
transmitting an update request of a radio map to the location server upon determining that an update of the assistance data is needed,
wherein the update request of the radio map includes an identifier of the radio map and indexes of the update points.
6. The method according to claim 5 , wherein the update request of the radio map further includes information about a moving direction and moving velocity of the terminal.
7. The method according to claim 1 , wherein the RSS value includes a mean of RSS values and a standard deviation of RSS values.
8. The method according to claim 1 , wherein the request for the assistance data includes:
an identifier of a specific radio map when the identifier of the specific radio map is assigned to the terminal.
9. The method according to claim 1 , wherein the request for the assistance data includes:
reference locations of a radio map requested by the terminal and identifiers of the reference locations.
10. The method according to claim 1 , wherein the request for the assistance data includes:
information indicating a geographic range of a radio map requested by the terminal based on an approximate location of the terminal.
11. The method according to claim 1 , wherein the request for the assistance data includes:
information about one or multiple access points accessible by the terminal.
12. The method according to claim 1 , wherein calculating the location of the terminal using the assistance data includes:
collecting RSS values from one or a plurality of access points at a current location of the terminal, comparing the collected RSS values with the RSS value of the radio map, and determining a reference point having a least difference or most similar pattern between the collected RSS values and the RSS value of the radio map as the location of the UE.
13. A terminal for calculating a location of the terminal in a wireless communication system, the terminal comprising:
a radio frequency (RF) unit; and
a processor in communication with the RF unit,
wherein the processor controls the RF unit such that the RF unit transmits a request for assistance data for calculating the location of the terminal to a location serve and receives the assistance data from the location server,
wherein the processor calculates the location of the terminal using the assistance data,
wherein the assistance data includes radio map information including a received signal strength (RSS) value from each of the one or more access points, collected from a plurality of reference points within an area of a predetermined range, and information about update points for which an update of a radio map is necessary, and
wherein the processor determines whether an update of the assistance data is needed based on the calculated location of the terminal and the information about the update points.