Method and apparatus for providing intelligent cellular handoff

• US 6,381,463 B1
• Filed: 02/05/1997
• Issued: 04/30/2002
• Est. Priority Date: 05/04/1995
• Status: Expired due to Fees

• Current Assignee: LGC Wireless Incorporated (TE Connectivity Limited)
• Original Assignee: Interwave Communications International SA (Alvarion Limited)
• Inventors: Tu, Jerome C., Chao, Pi-Hui
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): SMITH, SHEILA B
• Application Number:
  US08/790,206
• Time in Patent Office: 1,910 Days
• Field of Search: 455/436, 455/439, 455/440, 455/444, 455/456, 455/524, 455/525, 342/450, 342/457, 342/451, 342/452, 342/453, 342/454, 342/455, 342/456, 370/331, 340/991, 340/992, 340/993, 340/986, 375/150, 375/142, 375/325, 375/340, 375/341, 375/342, 375/343
• US Class Current: 455/456.5
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A cellular network includes a receiver configured to receive inbound information from a mobile station. A correlator is coupled to the receiver and configured to correlate the inbound information against expected information to generate a correlator signal. An interpolator is coupled to the correlator and configured to interpolate the correlator signal to generate an interpolator signal. A memory is coupled to the interpolator and configured to store the interpolator signal. A processor is coupled to the memory and configured to process the interpolator signal to determine a position of the mobile station. Additional embodiments track the position of the mobile station based on cellular hand off and mobile station position over time. The cellular network can transfer the mobile station from the microcellular network to the macrocellular network if the mobile station is moving rapidly. The cellular network can transfer the mobile station from the macrocellular network to the microcellular network if the mobile station is moving slowly. Advantages of the invention include the ability to reduce control traffic among the network elements including the BTS, BSC and MSC. As a result, the inventive network can handle more telephone calls and can organize the calls more efficiently than in traditional cellular networks.

Claims

1. A cellular base station for communicating with a mobile station and for determining a position of said mobile station, comprising:

a receiver configured to receive inbound information from said mobile station;

a correlator coupled to said receiver and configured to correlate said inbound information against expected information to generate a correlator signal;

an interpolator coupled to said correlator and configured to interpolate said correlator signal to generate an interpolator signal;

a memory coupled to said interpolator and configured to store said interpolator signal; and

a processor coupled to said memory and configured to process said interpolator signal to determine a position of said mobile station.

2. The base station of claim 1, wherein:

said inbound information includes a plurality of bursts;

said correlator signal includes a correlator signal corresponding to each of said bursts;

said interpolator signal includes an interpolator signal corresponding to each of said correlator signals;

said memory is configured to store said interpolator signals; and

said processor is configured to process said interpolator signals to determine said position of said mobile station.

3. The base station of claim 2, wherein:

said interpolator is configured to low-pass-filter said interpolator signals; and

said processor is configured to process said interpolator signals by a statistical technique to determine said position of said mobile station.

4. The base station of claim 2, wherein:

said interpolator is configured to low-pass-filter said interpolator signals; and

said processor is configured to process said interpolator signals by an averaging technique to determine said position of said mobile station.

5. A cellular network for providing intelligent cellular handoff of a mobile station, comprising:

a plurality of base stations, each base station including;

(a) a receiver configured to receive inbound information from said mobile station;

(b) a correlator coupled to said receiver and configured to correlate said inbound information against expected information to generate a correlator signal;

(c) an interpolator coupled to said correlator and configured to interpolate said correlator signal to generate an interpolator signal;

(d) a memory coupled to said interpolator and configured to store said interpolator signal; and

(e) a processor coupled to said memory and configured to process said interpolator signal to determine a position of said mobile station; and

a mobile switching structure coupled to said base stations and configured to store said position of said mobile station over time and to determine whether to handoff said mobile station from a first base station to a second base station.

6. The cellular network of claim 5, wherein for each base station:

said inbound information includes a plurality of bursts;

said correlator signal includes a correlator signal corresponding to each of said bursts;

said interpolator signal includes an interpolator signal corresponding to each of said correlator signals;

said memory is configured to store said interpolator signals; and

said processor is configured to process said interpolator signals to determine said position of said mobile station.

7. The cellular network of claim 6, wherein for each base station:

said interpolator is configured to low-pass-filter said interpolator signals; and

said processor is configured to process said interpolator signals by a statistical technique to determine said position of said mobile station.

8. The cellular network of claim 6, wherein for each base station:

said interpolator is configured to low-pass-filter said interpolator signals; and

said processor is configured to process said interpolator signals by an averaging technique to determine said position of said mobile station.

9. The cellular network of claim 5, wherein:

said mobile switching structure is configured to determine whether to handoff said mobile station from a first base station to a second base station based at least in part on a mobile station position trend.

10. The cellular network of claim 5, wherein:

said base stations are configured to measure channel condition information regarding said inbound information more often than said mobile station; and

said mobile switching structure is configured to determine whether to handoff said mobile station from a first base station to a second base station based at least in part on said channel condition information.

11. The cellular network of claim 5, wherein:

said base stations are configured to measure channel condition information regarding said inbound information more often than said mobile station; and

said mobile switching structure is configured to determine whether to handoff said mobile station from a first base station to a second base station based at least in part on a mobile station position trend and said channel condition information.

12. A cellular network for providing intelligent cellular handoff of a mobile station, comprising:

a plurality of macrocell base stations;

a plurality of microcell base stations, each microcell base station including;

(a) a receiver configured to receive inbound information from said mobile station;

(b) a correlator coupled to said receiver and configured to correlate said inbound information against expected information to generate a correlator signal;

(c) an interpolator coupled to said correlator and configured to interpolate said correlator signal to generate an interpolator signal;

(d) a memory coupled to said interpolator and configured to store said interpolator signal; and

(e) a processor coupled to said memory and configured to process said interpolator signal to determine a position of said mobile station; and

a mobile switching structure coupled to said macrocell base stations and to said microcell base stations and configured to store said position of said mobile station over time and to determine whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station.

13. The cellular network of claim 12, wherein for each base station:

said inbound information includes a plurality of bursts;

said correlator signal includes a correlator signal corresponding to each of said bursts;

said interpolator signal includes an interpolator signal corresponding to each of said correlator signals;

said memory is configured to store said interpolator signals; and

said processor is configured to process said interpolator signals to determine said position of said mobile station.

14. The cellular network of claim 13, wherein for each base station:

said interpolator is configured to low-pass-filter said interpolator signals; and

said processor is configured to process said interpolator signals by a statistical technique to determine said position of said mobile station.

15. The cellular network of claim 13, wherein:

said mobile switching structure is configured to determine whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station based at least in part on a mobile station position trend.

16. A cellular network for providing intelligent cellular handoff of a mobile station, comprising:

a plurality of macrocell base stations;

a plurality of microcell base stations configured to receive inbound information from said mobile station; and

a mobile switching structure coupled to said macrocell base stations and to said microcell base stations and configured to store information associated with the relationship between said mobile station with a specific microcell base station over time and to determine whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station.

17. The cellular network of claim 16, wherein:

said mobile switching structure is configured to determine whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station based at least in part on a mobile station position trend.

18. The cellular network of claim 16, wherein:

said base stations are configured to measure channel condition information regarding said inbound information more often than said mobile station; and

said mobile switching structure is configured to determine whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station based at least in part on said channel condition information.

19. The cellular network of claim 16, wherein:

said base stations are configured to measure channel condition information regarding said inbound information more often than said mobile station; and

said mobile switching structure is configured to determine whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station based at least in part on a mobile station position trend and said channel condition information.

20. A method of communicating between a base station and a mobile station and for determining a position of said mobile station, comprising the steps of:

receiving inbound information from said mobile station;

correlating said inbound information against expected information to generate a correlator signal;

interpolating said correlator signal to generate an interpolator signal;

storing said interpolator signal; and

processing said interpolator signal to determine a position of said mobile station.

21. The method of claim 20, wherein:

said inbound information includes a plurality of bursts;

said correlating step is performed by correlating each of said bursts to generate a plurality of correlator signals;

said interpolating step is performed by interpolating each of said correlator signals to generate a plurality of interpolator signals;

said storing step is performed by storing said interpolator signals; and

said processing step is performed by processing said interpolator signals to determine said position of said mobile station.

22. The method of claim 21, wherein:

said interpolating step includes the step of low-pass-filtering said interpolator signals; and

said processing step includes the step of processing said interpolator signals by a statistical technique to determine said position of said mobile station.

23. The method of claim 21, wherein:

said interpolating step includes the step of low-pass-filtering said interpolator signals; and

said processing step includes the step of processing said interpolator signals by an averaging technique to determine said position of said mobile station.

24. A method in a cellular network having a plurality of base stations and a mobile switching structure coupled to said base stations for providing intelligent cellular handoff of a mobile station among said base stations, comprising the steps of:

for each base station, performing the steps including;

(a) receiving inbound information from said mobile station;

(b) correlating said inbound information against expected information to generate a correlator signal;

(c) interpolating said correlator signal to generate an interpolator signal;

storing said interpolator signal; and

(d) processing said interpolator signal to determine a position of said mobile station; and

for said mobile switching structure, performing the steps including;

(a) storing said position of said mobile station over time; and

(b) determining whether to handoff said mobile station from a first base station to a second base station.

25. The method of claim 24, wherein for each base station:

said inbound information includes a plurality of bursts;

said correlating step is performed by correlating each of said bursts to generate a plurality of correlator signals;

said interpolating step is performed by interpolating each of said correlator signals to generate a plurality of interpolator signals;

said storing step is performed by storing said interpolator signals; and

said processing step is performed by processing said interpolator signals to determine said position of said mobile station.

26. The method of claim 25, wherein for each base station:

said interpolating step includes the step of low-pass-filtering said interpolator signals; and

said processing step includes the step of processing said interpolator signals by a statistical technique to determine said position of said mobile station.

27. The method of claim 25, wherein for each base station:

said interpolating step includes the step of low-pass-filtering said interpolator signals; and

said processing step includes the step of processing said interpolator signals by an averaging technique to determine said position of said mobile station.

28. The method of claim 24, wherein for said mobile switching structure:

said determining step is performed based at least in part on a mobile station position trend.

29. The method of claim 24, wherein:

for said base station, said receiving step includes the step of measuring channel condition information regarding said inbound information more often than said mobile station; and

for said mobile switching structure, said determining step is performed base;

at least in part on said channel condition information.

30. The method of claim 24, wherein:

for said base station, said receiving step includes the step of measuring channel condition information regarding said inbound information more often than said mobile station; and

for said mobile switching structure, said determining step is performed based at least in part on a mobile station position trend and said channel condition information.

31. A method in a cellular network having a plurality of macrocell base stations, a plurality of microcell base stations and a mobile switching structure coupled to said macrocell base stations and said microcell base stations for providing intelligent cellular handoff of a mobile station among said macrocell base stations and said microcell base stations, comprising the steps of:

for each microcell base station, performing the steps including;

(a) receiving inbound information from said mobile station;

(b) correlating said inbound information against expected information to generate a correlator signal;

(c) interpolating said correlator signal to generate an interpolator signal;

storing said interpolator signal; and

(d) processing said interpolator signal to determine a position of said mobile station; and

for said mobile switching structure, performing the steps including;

(a) storing said position of said mobile station over time; and

(b) determining whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station.

32. The method of claim 31, wherein for each microcell base station:

said inbound information includes a plurality of bursts;

said correlating step is performed by correlating each of said bursts to generate a plurality of correlator signals;

said interpolating step is performed by interpolating each of said correlator signals to generate a plurality of interpolator signals;

said storing step is performed by storing said interpolator signals; and

said processing step is performed by processing said interpolator signals to determine said position of said mobile station.

33. The method of claim 32, wherein for each base station:

said interpolating step includes the step of low-pass-filtering said interpolator signals; and

said processing step includes the step of processing said interpolator signals by a statistical technique to determine said position of said mobile station.

34. The method of claim 32, wherein for said mobile switching structure:

said determining step is performed based at least in part on a mobile station position trend.

35. A method in a cellular network having a plurality of macrocell base stations, a plurality of microcell base stations and a mobile switching structure coupled to said macrocell base stations and said microcell base stations for providing intelligent cellular handoff of a mobile station among said macrocell base stations and said microcell base stations, comprising the steps of:

for each microcell base station, performing the steps including;

(a) receiving inbound information from said mobile station; and

for said mobile switching structure, performing the steps including;

(a) storing information associated with the relationship between said mobile station with a specific microcell base station over time; and

(b) determining whether to handoff said mobile station from one of a macrocell base station to a microcell base station and a microcell base station to a macrocell base station.

36. The method of claim 35, wherein for said mobile switching structure:

said determining step is performed based at least in part on a mobile station position trend.

37. The method of claim 35, wherein:

for said base station, said receiving step includes the step of measuring channel condition information regarding said inbound information more often than said mobile station; and

for said mobile switching structure, said determining step is performed based at least in part on said channel condition information.

38. The method of claim 35, wherein:

for said base station, said receiving step includes the step of measuring channel condition information regarding said inbound information more often than said mobile station; and

for said mobile switching structure, said determining step is performed based at least in part on a mobile station position trend and said channel condition information.