Method for discovery of indoor lci based on approximate location

Abstract

As part of a localized positioning solution, a mobile device may transmit a request message to a server to obtain information about location contexts near the mobile device. In response, the server may, in some implementations, transmit a response message back to the mobile device that identifies a list of nearby LCIs and an area that encompasses these LCIs. The mobile device may store the returned LCI information and the returned area information in corresponding databases for later use. In some implementations, time limits may be placed on the returned area information after which the information is deemed stale.

1 . A machine implemented method for managing location context identifier (LCI) requests received from a mobile device, comprising:
 receiving a request message for one or more LCIs from said mobile device, said request message including location information;   determining a region associated with said location information; and   if there are no known LCIs within said region associated with said location information, transmitting a response message to said mobile device in response to said request message that indicates an unavailability of LCIs in said region.   
     
     
         2 . The method of  claim 1 , wherein:
 said response message includes an empty list of LCIs.   
     
     
         3 . The method of  claim 1 , further comprising:
 if there are no known LCIs within said region associated with said location information, determining an area that encompasses said region associated with said location information and that includes no known LCIs, wherein said response message includes an indication of said area.   
     
     
         4 . The method of  claim 3 , wherein:
 determining said area that encompasses said region associated with said location information includes identifying an area that is larger than said region associated with said location information if there are no known LCIs just outside a boundary of said region.   
     
     
         5 . The method of  claim 3 , further comprising:
 determining said area that encompasses said region associated with said location information includes identifying an area that is as large as possible, up to a limit, without encompassing any known LCIs.   
     
     
         6 . The method of  claim 3 , wherein:
 said response message includes a time-to-live indication identifying a time after which said indication of said area is considered stale.   
     
     
         7 . The method of  claim 1 , wherein:
 said location information includes an estimate of a location of said mobile device.   
     
     
         8 . The method of  claim 7 , wherein:
 said estimate of said location of said mobile device includes a position indication and an uncertainty value.   
     
     
         9 . The method of  claim 1 , further comprising:
 if there are one or more known LCIs within said region associated with said location information, transmitting a response message to said mobile device in response to said request message that includes a list of said one or more known LCIs.   
     
     
         10 . The method of  claim 9 , wherein:
 said response message that includes said list of said one or more known LCIs also includes an indication of an area that encompasses said one or more known LCIs.   
     
     
         11 . A machine implemented method for obtaining location context identifier (LCI) information at a mobile device, comprising:
 transmitting a request message for one or more location context identifiers (LCIs) from a mobile device, said request message including location information; and   receiving a response message from a server in response to said request message indicating an unavailability of LCIs if there are no known LCIs within a region associated with said location information.   
     
     
         12 . The method of  claim 11 , wherein:
 said response message further includes an indication of an area that encompasses said region associated with said location information if there are no known LCIs within said region associated with said location information, wherein said area that encompasses said region also includes no known LCIs.   
     
     
         13 . The method of  claim 12 , wherein:
 if there are no known LCIs just outside a boundary of said region, said area that encompasses said region associated with said location information is larger than said region associated with said location information.   
     
     
         14 . The method of  claim 12 , wherein:
 said response message further includes a time-to-live indication identifying a time after which said indication of said area is considered stale.   
     
     
         15 . The method of  claim 12 , further comprising:
 storing said area in a previously returned areas database.   
     
     
         16 . The method of  claim 11 , wherein:
 said response message includes an empty list of Las.   
     
     
         17 . The method of  claim 11 , further comprising:
 if there are one or more known LCIs within said region associated with said location information, receiving a response message from said server in response to said request message that indicates said one or more known LCIs.   
     
     
         18 . The method of  claim 17 , wherein:
 said response message that indicates said one or more known LCIs also includes an indication of an area that encompasses said one or more known LCIs.   
     
     
         19 . The method of  claim 18 , further comprising:
 storing information indicative of said one or more known LCIs in a local database and storing information indicative of said area that encompasses said one or more known LCIs in a previously received areas database.   
     
     
         20 . A machine implemented method comprising:
 determining at a mobile device that a location context identifier (LCI) is desired;   searching a local database of said mobile device using an estimated location of said mobile device if said estimated location is within areas previously returned by one or more directory servers; and   transmitting a request message for one or more LCIs from said mobile device if said estimated location is outside areas previously returned by said one or more directory servers.   
     
     
         21 . The method of  claim 20 , further comprising:
 after transmitting said request message, receiving a response message from a first directory server responsive to said request message, said response message including a list of LCIs identifying areas in a vicinity of said estimated location.   
     
     
         22 . The method of  claim 21 , wherein:
 said response message further includes an indication of an area that encompasses said estimated location and said LCIs in said list of LCIs if said list of LCIs has at least one LCI.   
     
     
         23 . The method of  claim 22 , further comprising:
 after receiving said response message, storing said area in a previously returned areas database and storing LCI information from said list of LCIs in said local database.   
     
     
         24 . The method of  claim 23 , wherein:
 area information stored within said previously returned areas database is time limited.   
     
     
         25 . The method of  claim 21 , wherein:
 said response message includes an empty list of LCIs if said first directory server finds no LCIs identifying areas in said vicinity of said estimated location.   
     
     
         26 . The method of  claim 25 , wherein:
 said response message further includes an indication of an area within which said mobile device is not to transmit a subsequent request message if said list of LCIs is empty.   
     
     
         27 . The method of  claim 26 , further comprising:
 after receiving said response message, storing said indication of said area within which said mobile device is not to transmit a subsequent request message in a previously returned areas database.   
     
     
         28 . An apparatus comprising:
 means for initiating transmission of a request message for one or more location context identifiers (LCIs) from a mobile device, said request message including location information; and   means for processing a response message received from a server in response to said request message that indicates an unavailability of LCIs if said server is unable to determine any known LCIs within a region associated with said location information.   
     
     
         29 . An article comprising:
 a non-transitory storage medium having machine-readable instructions stored thereon that are executable by a special purpose computing apparatus to:   initiate transmission of a request message for one or more location context identifiers (LCIs) from a mobile device, said request message including location information; and   process a response message received from a server in response to said request message that indicates an unavailability of LCIs, if said server is unable to identify any known LCIs within a region associated with said location information.   
     
     
         30 . A mobile device comprising:
 a transceiver; and   a processor to:
 initiate transmission of a request message through said transceiver for one or more location context identifiers (LCIs), said request message including location information; and 
 process a response message received at said transceiver from a server in response to said request message that indicates an unavailability of LCIs, if said server is unable to identify any known LCIs within a region associated with said location information. 
   
     
     
         31 . An apparatus comprising:
 means for determining at a mobile device that a location context identifier (LCI) is desired;   means for searching a local database of said mobile device for LCI information using an estimated location of said mobile device if said estimated location is within areas previously returned by one or more directory servers; and   means for initiating transmission of a request message for one or more LCIs from said mobile device if said estimated location is outside areas previously returned by said one or more directory servers, said request message including at least an indication of said estimated location of said mobile device.   
     
     
         32 . An article comprising
 a non-transitory storage medium having machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to:   determine at a mobile device that a location context identifier (LCI) is desired;   search a local database of said mobile device for LCI information using an estimated location of said mobile device if said estimated location is within areas previously returned by one or more directory servers; and   initiate transmission of a request message for one or more LCIs from said mobile device if said estimated location is outside areas previously returned by said one or more directory servers, said request message including at least an indication of said estimated location of said mobile device.   
     
     
         33 . A mobile device comprising:
 a transmitter; and   a processor to:
 determine that a location context identifier (LCI) is desired; 
 search a local database of said mobile device for LCI information using an estimated location of said mobile device if said estimated location is within areas previously returned by one or more directory servers; and 
 initiate transmission of a request message through said transmitter for one or more LCIs from said mobile device if said estimated location is outside areas previously returned by said one or more directory servers, said request message including at least an indication of said estimated location of said mobile device.