Apparatus and method for positioning mobile station

An apparatus for calculating an enhanced observed time difference from a mobile station and transmitting the enhanced observed time difference to a servicing mobile location center for a location-based service, the apparatus comprising:

• a period checker unit adapted to determine if a predetermined period has arrived;
• a detector unit adapted to detect the intensity of received signals whenever the period has arrived for detecting the intensity of received signals for an entire channel;
• a first memory for storing a database of the intensity of received signals detected by the detector unit;
• and
• a controller unit adapted to choose a base transceiver station, the synchronization channel of which is to be measured, when a location-measuring request and assistance data are received from the servicing mobile location center, based on response time detected from the location-measuring request and a predetermined priority, calculate an enhanced observed time difference for the chosen base transceiver station and transmit a location-measuring response, including the calculation result, to the servicing mobile location center,
• wherein said priority is set to a priority order of:
• [1] an overlap between a channel list included in the assistance data and a list of a number of nearby cells, having a higher priority level than [2] a broadcast control channel allocation list excepting the channel list included in the assistance data and the list of nearby cells, having a higher priority level than [3] a cell having the strongest signal intensity among the remaining base transceiver stations.

A method for calculating an enhanced observed time difference from a mobile station and transmitting the enhanced observed time difference to a servicing mobile location center for a location-based service, the method comprising:

• receiving a location-measuring request and assistance data from the servicing mobile location center via a radio resource link protocol;
• choosing a base transceiver station, the synchronization channel of which is to be measured, based on response time detected from the location-measuring request and a predetermined priority;
• and
• receiving the synchronization channel of the chosen base transceiver station, calculating an enhanced observed time difference for the chosen base transceiver station, and transmitting a location-measuring response, including the calculation result, to the servicing mobile location center via the radio resource link protocol,
• wherein a first priority is assigned to an overlap between a channel list included in the assistance data and a list of a number of nearby cells, and a second priority is assigned to a broadcast control channel allocation list.

A method for calculating an enhanced observed time difference from a mobile station and transmitting the enhanced observed time difference to a servicing mobile location center for a location-based service, the method comprising:

• determining if a detection period has arrived;
• detecting and storing the intensity of received signals for the entire channel when the period has arrived;
• receiving a location-measuring request and assistance data via a cordless resource link protocol;
• choosing a base transceiver station, the synchronization channel of which can be measured, based on response time detected from the location-measuring request and predetermined priority;
• and
• receiving the synchronization channel of the chosen base transceiver station, calculating an enhanced observed time difference for the chosen base transceiver station and transmit a location-measuring response, including the calculation result, to the servicing mobile location center via the radio resource link protocol,
• wherein a first priority is assigned to an overlap between a channel list included in the assistance data and a list of six nearby cells, a second priority is assigned to a broadcast control channel allocation list, and a third priority is assigned to a channel having the strongest signal intensity stored in the second step.