Hand-off between ultra-wideband cell sites

• US 20050048978A1
• Filed: 03/12/2001
• Published: 03/03/2005
• Est. Priority Date: 12/14/2000
• Status: Active Grant

• Current Assignee: Intellectual Ventures Holding 81 LLC (Intellectual Ventures LLC)
• Original Assignee: Pulse-Link Incorporated
• Inventors: Jolly, Donald W., Santhoff, John H., Arrieta, Rodolfo T.
• Granted Patent: US 6,907,244 B2
• Time in Patent Office: Days
• US Class Current: 455/442
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/7174 Pulse generation in general H04L25/03834
• CPC Class Codes: H04B 1/7176 Data mapping, e.g. modulation
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1816 with retransmission of the same, encoded, message
• CPC Class Codes: H04L 1/1829 Arrangements specially adapted for the receiver end
• CPC Class Codes: H04L 1/203 Details of error rate determination, e.g. BER, FER or WER
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data

Abstract

Briefly, the present invention provides a dynamic channel re-assignment capability between mobile units, base stations and sectors within base station coverage areas. The wireless devices used in the present invention may include impulse radio communication devices such as, for example ultra-wideband radio (also known as digital pulse wireless) communication devices. Ultra-wideband bandwidth and channel allocation can be effectively managed, even though link quality generally deteriorates near the outer boundary of the base station. By maintaining dual communications with an adjoining base station, the present invention reduces the bit error rate and maintains signal strength (e.g., RF signal strength). This procedure is termed a “soft-handoff”.

Claims

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15. A method for performing a soft hand-off in an ultra-wideband code-based cellular communication system, wherein the soft hand-off is from a first mobile unit to a second mobile unit to a base station, the method comprising the steps of:

monitoring signal strength and the bit error rate from a first base station and determining that either is unacceptable;

attempting to locate an adjacent base station with an acceptable signal strength and bit error rate and determining that no adjacent base station has an acceptable signal strength and bit error rate;

transmitting a hand-off request from a first mobile device that is linked to the first base station to a second mobile device;

receiving a response from the second mobile device; and

using the second mobile device

as a temporary repeater to pass data to a second base station.

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20. A computer program product for performing a soft hand-off in an ultra-wideband code-based cellular communication system, wherein the soft hand-off is from a first mobile unit to a second mobile unit to a base station, comprising:

computer code for monitoring signal strength and the bit error rate from a first base station and determining that either in unacceptable;

computer code for attempting to locate an adjacent base station with an acceptable signal strength and bit error rate and determining that no adjacent base station has an acceptable signal strength and bit error rate;

computer code for transmitting a hand-off request from a first mobile device that is linked to the first base station to a second mobile device;

computer code for receiving a response from the second mobile device; and

computer code for using the second mobile device as a temporary repeater to pass data to a second base station.

21. A system for performing a soft hand-off in an ultra-wideband code-based cellular communication system, wherein the soft hand-off is from a first mobile unit to a second mohi Is unit to a base station, the system comprising:

means for monitoring signal strength and the bit error rate from a first base station and determining that either is unacceptable;

means for attempting to locate an adjacent base station with an acceptable signal strength and hit error rate and determining that no adjacent base station has an acceptable signal strength and bit error rate;

means for transmitting a hand-off request from a first mobile device that is linked to the first base station to a second mobile device;

means for receiving a response from the second mobile device; and

means for using the second mobile device as a temporary repeater to pass data to a second base station.

22. A mobile unit for an ultra-wideband code-based cellular communication system, wherein mobile unit performs a soft hand-off to a second mobile unit to a base station, the mobile unit comprising:

means for monitoring signal strength and the bit error rate from a first base station to which it is linked sod determining that either is unacceptable;

means for attempting to locate an adjacent base station with an acceptable signal strength and bit error rate and determining that no adjacent base station has an acceptable signal strength and bit error rate;

means for transmitting a hand-off request to a second mobile device;

means for receiving a response from the second mobile device; and

means for using the second mobile device as a temporary repeater to pass data to a second base station.

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26. A base station system for an ultra-wideband code-based cellular communication system, wherein there is a soft hand-off from a first mobile unit to a second mobile unit to the base station, the base station comprising:

means for monitoring signal strength and the bit error rate from the first base station and determining that either is unacceptable; and

means for attempting to locate an adjacent base station with an acceptable signal strength and bit error rate and determining that no adjacent base station has an acceptable signal strength and bit error rate.

27. A method for performing a soft hand-off in an ultra-wideband cellular communication system, comprising the steps of:

monitoring a signal strength and a bit error rate from a first base station;

monitoring the signal strength and the bit error rate from a second base station;

comparing the signal strength and the bit error rate from the first base station to the signal strength and the bit error rate from the second base station or to predetermined levels;

transferring data reception and transmission from the first base station to the second base station when the signal strength from the second base station is greater than the signal strength of the first base station or when the bit error rate of the second base station is less than the bit error rate of the first base station or when either signal strength or bit error rate is below a pre-determined level;

wherein

a mobile device is linked to the first base station and requests the position of a plurality of base stations;

the plurality of base stations reply;

the mobile unit determines and stores the location of each of the base stations;

each of the base stations transmits an associated rating to the mobile device;

the mobile device calculates the data integrity of each base station and establishes a link with a base station having the highest data integrity; and

the mobile device transmits a link curtailment to the first base station.

28. A computer program product for performing a soft hand-off in an ultra-wideband code-based cellular communication system, comprising:

computer code for monitoring a signal strength and a bit error rate from a first base station;

computer code for monitoring the signal strength and the bit error rate from a second base station;

computer code for comparing the signal strength and the bit error rate from the first base station to the signal strength and the bit error rate from the second base station or to predetermined levels;

computer code for transferring data reception and transmission from the first base station to the second base station when the signal strength from the second base station is greater than the signal strength of the first base station or when the bit error rate of the second base station is less than the bit error rate of the first base station or when either signal strength or bit error rate is below a pre-determined level;

wherein

a mobile device is linked to the first base station and requests the position of a plurality of base stations;

the plurality of base stations reply;

the mobile unit determines and stores the location of each of the base stations;

each of the base stations transmits an associated rating to the mobile device;

the mobile device calculates the data integrity of each base station and establishes a link with a base station having the highest data integrity; and

the mobile device transmits a link curtailment to the first base station.

29. A base station for an ultra-wideband code based cellular communication system comprising:

means for monitoring a signal strength and a bit error rate from the base station;

means for comparing the signal strength and the bit error rate from the base station to predetermined levels;

means for transferring data reception and transmission to a second base station;

wherein

a mobile device is linked to the base station and requests the position of a plurality of base stations;

the plurality of base stations reply;

the mobile unit determines and stores the location of each of the base stations;

each of the base stations transmits an associated rating to the mobile device;

the mobile device calculates the data integrity of each base station and establishes a link with a base station having the highest data integrity; and

the mobile device transmits a link curtailment to the base station.