Automatic cell transfer based on reverse channel characteristics

• US 6,035,196 A
• Filed: 08/25/1997
• Issued: 03/07/2000
• Est. Priority Date: 08/25/1997
• Status: Expired due to Term

• Current Assignee: Eagle Technology, LLC (L3Harris Technologies, Inc.)
• Original Assignee: The Whitaker Corporation (Meggitt PLC)
• Inventors: Hengeveld, Thomas, Martinez, Dennis
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): NGUYEN, DUC M
• Application Number:
  US08/918,277
• Time in Patent Office: 925 Days
• Field of Search: 455/436, 455/437, 455/439, 455/421, 455/452, 455/442, 455/443, 455/440, 455/441, 370/331-333
• US Class Current: 455/437
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/36 by user or terminal equipment

Abstract

In a distributed communication system, a mobile initiates a cell transfer or channel top based upon an assessment of measured parameters on the reverse channel. Advantageously, a mobile initiates a cell transfer in response to either a reverse channel utilization or reverse channel success rate.

Claims

1. A cell transfer method, comprising:

measuring by a mobile one or more reverse channel transmission parameters in a communications link between a base station and the mobile;

assessing by the mobile the one or more measured transmission parameters against one or more thresholds;

initiating by the mobile a search for an alternate communications link in accordance with the assessment.

2. A cell transfer method as recited in claim 1 wherein the step of measuring the transmission parameters of the reverse channel includes measuring the reverse channel transmission success rate comprising:

transmitting a reverse channel message block,

transmitting a forward channel message block with an indication as to whether the reverse channel message block was received, and assessing the quantity of transmitted and received reverse channel message blocks relative to the quantity of transmitted reverse channel message blocks.

3. A cell transfer method as recited in claim 2 wherein measuring one or more reverse channel transmission parameters comprise measuring reverse channel utilization.

4. A cell transfer method as recited in claim 3 wherein the step of assessing utilization comprises:

assessing the quantity of idle reverse channel message blocks relative to the total number of reverse channel message blocks.

5. A cell transfer method as recited in claim 2 and further comprising:

determining the one or more thresholds against which the reverse channel transmission success rate is compared, values of the one or more thresholds being based upon the forward channel received signal strength,

comparing the threshold value against the measured reverse channel transmission success rate, and

offering a decision to transfer to a second base station if the measured reverse channel transmission success rate is below the determined one or more threshold values.

6. A cell transfer method as recited in claim 2 wherein values of the one or more thresholds are fixed quantities known by the mobile.

7. A cell transfer method as recited in claim 2 wherein values of the one or more thresholds are dynamic quantities.

8. A cell transfer method as recited in claim 2 wherein values of the one or more thresholds are offered by a user of the mobile.

9. A cell transfer method as recited in claim 8 and further comprising:

determining a first threshold value,

comparing the first threshold value against the reverse transmission success rate,

offering a first decision to transfer,

determining a second threshold value,

comparing the second threshold value against the reverse channel utilization,

offering a second decision to transfer, and

transferring the communication link from the established communications link to an alternate communications link if either the first or second decision to transfer is affirmative.

10. A cell transfer method as recited in claim 8 and further comprising:

determining a first threshold value,

comparing the first threshold value against the reverse channel transmission success rate,

offering a first decision to transfer,

determining a second threshold value,

comparing the second threshold value against the reverse channel utilization,

offering a second decision to transfer, and

transferring the communication link from the established communications link to an alternate communications link if the first and second decision to transfer is affirmative.

11. A cell transfer method as recited in claim 1 wherein measuring one or more reverse channel transmission parameters comprises measuring reverse channel utilization.

12. A cell transfer method as recited in claim 1 wherein measuring one or more reverse channel transmission parameters includes measuring a reverse channel utilization comprising assessing the quantity of transmitted and received reverse message blocks relative to the quantity of transmitted reverse channel message blocks and further comprising assessing the reverse channel utilization.

13. A cell transfer method as recited in claim 1 wherein measuring one or more reverse channel transmission parameters comprises:

transmitting continuously in time forward channel message blocks on the forward channel, each message block indicating whether a respective reverse channel message block is idle.

14. A cell transfer method as recited in claim 13 and further comprising:

determining values of the one or more thresholds against which the reverse channel utilization is compared by calculation of a cell transfer advisability parameter as a function of reverse channel utilization,

generating a random number within a possible range of the cell transfer advisability parameters,

comparing the random number against the cell transfer advisability parameter, and

offering a decision to transfer to a second base station if the cell transfer advisability parameter is greater than the random number.

15. A cell transfer method as recited in claim 1 wherein searching occurs only if the mobile has transmitted on the reverse channel without success.

16. A cell transfer method as recited in claim 1 wherein measuring the reverse channel transmission parameters further comprises:

measuring a reverse channel transmission success rate, and

measuring a reverse channel utilization.