Location identification

• US 7,522,926 B2
• Filed: 11/21/2005
• Issued: 04/21/2009
• Est. Priority Date: 11/26/2004
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Zhu, Ting Yong, Zhang, Ling, Chu, Heng
• Primary Examiner(s): Bhattacharya; Sam
• Application Number:
  US11/284,115
• Publication Number:
  US 20060114145A1
• Time in Patent Office: 1,247 Days
• Field of Search: 455 412- 413, 455/404.2, 4554561-457, 701/207, 701/213, 701/216, 34235701-3571
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/0295 Proximity-based methods, e.g. position inferred from reception of particular signals

Abstract

The location of a mobile terminal may be determined in response to signals received from a plurality of RFIDs. Information from a plurality of RFIDs for determining a location of a mobile terminal is received by the mobile terminal. The mobile terminal may maintain an in-range list that comprises all the RFIDs in which the mobile terminal is currently within their coverage range. The location of the mobile terminal is calculated in response to the received information for determining a location by calculating the common coverage area of the RFIDs in the in-range list.

Claims

1. A method for location identification, comprising:

receiving information from a plurality of RFIDs for determining a location of a mobile terminal;

maintaining an in-range list that comprises all the RFIDs in which said mobile terminal is currently within their coverage range;

calculating the location of the mobile terminal in response to said received information for determining a location by calculating the common coverage area of said RFIDs in said in-range list, wherein the information for determining a location from said RFID comprises the location information of said RFID and the coverage range information of said RFID;

maintaining an out-range list that comprises a list of the RFIDs that said mobile terminal is currently out of their coverage range, wherein calculating said mobile terminal'"'"'s location range comprises subtracting the coverage range of each RFID in said out-range list from the common coverage area of said RFIDs in said in-range list, and the information for determining a location from said RFID further comprises the location information of RFID'"'"'s neighboring said RFIDs and said neighboring RFID'"'"'s respective coverage range information;

adding a new RFID to said in-range list when said mobile terminal receives a signal from said RFID; and

adding said neighboring RFIDs that are not present in the in-range list to said out-range list according to the information that comes from said RFID and that represents the location of said neighboring RFIDs and their respective coverage range.

2. A mobile terminal, comprising:

a RFID reader for receiving information for determining a location from a plurality of RFIDs;

a location determination module for determining said mobile terminal'"'"'s location according to the information for determining a location from said plurality of RFIDs;

said location determination module comprising;

an in-range list maintaining unit for maintaining an in-range list that comprises all the RFIDs that said mobile terminal is currently within their coverage range; and

an intersection range calculating unit for calculating a common coverage range of said RFIDs in said in-range list, wherein

said location determination module farther comprises;

an out-range list maintaining unit for maintaining an out-range list that comprises all of the RFIDs that said mobile terminal is currently out of their coverage range, and

an exclusion range calculating unit for subtracting the coverage range of each RFID in said out-range list from the common coverage range calculated by said intersection range calculating unit,

said RFID reader farther receives location-based service information from said RFIDs,

said mobile terminal farther comprises a service information storing means for storing said location-based service information,

said plurality of RFIDs comprise;

a plurality of sub-RFIDs, each sub-RFID is used to store and transmit one information segment, and

a main RFID for storing and transmitting the information representing the sequence of the information segments stored in said plurality of sub-RFIDs.

3. A computer usable medium having computer readable instructions embodied therein for location determination, the computer readable instructions, when executed on a computer system, causing the computer system to perform the operations comprising:

receiving information from a plurality of RFIDs for determining a location of a mobile terminal;

maintaining an in-range list that comprises all the RFIDs in which said mobile terminal is currently within their coverage range;

calculating the location of the mobile terminal in response to said received information for determining a location by calculating the common coverage area of said RFIDs in said in-range list, wherein the information for determining a location from said RFID comprises the location information of said RFID and the coverage range information of said RFID;

maintaining an out-range list that comprises a list of the RFIDs that said mobile terminal is currently out of their coverage range, wherein calculating said mobile terminal'"'"'s location range comprises subtracting the coverage range of each RFID in said out-range list from the common coverage area of said RFIDs in said in-range list, and the information for determining a location from said RFID further comprises the location information of RFID'"'"'s neighboring said RFIDs and said neighboring RFID'"'"'s respective coverage range information;

adding a new RFID to said in-range list when said mobile terminal receives a signal from said RFID; and

adding said neighboring RFIDs that are not present in the in-range list to said out-range list according to the information that comes from said RFID and that represents the location of said neighboring RFIDs and their respective coverage range.