EP1487230B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for merging pilot neighbor lists in a mobile telephone system
Assignee: Qualcomm Inc
•
Filing: 1998-02-13
•
Granted: 2010-10-27
•
Expires: 2018-02-13
Abstract
No abstract record available.
Inventors
- 👤 Walid M. c/o QUALCOMM Incorporated Hamdy
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 11:39
CPC Classifications
H; H04; H04W; H04W36/00; H04W36/0005; H04W36/0055; H04W36/0061
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
143 words
An apparatus for controlling handoff of a mobile station (18) from a first base station (12) to a second base station (14) by monitoring the strength of pilot signals received by the mobile station from a plurality of base stations (12, 14, 16) including the first and second base stations, the apparatus comprising: means for receiving data from the mobile station (18) representing the strength and phase of the pilot signals received by the mobile station and identifying active and candidate base stations including the first and second base stations (12, 14); and means for determining a ranked list of neighboring base stations to the mobile station (18), the ranked list depending on the strength of each pilot signal received by the mobile station and the number of times that a base station is found as a neighbor of each pilot signal received.
Claim 2
Dependent Claim
185 words
The apparatus of claim 1, wherein the means for determining (30) further comprise: means for reprieving from a memory unit (32), a fixed, predetermined neighbor list for each of said pilot signals that said mobile station is presently communicating with and whose corresponding round trip delay time does not exceed a predetermined threshold; means for generating a union of neighboring base stations from fixed, predetermined neighbor lists; means for removing from said union any member of said union which is a member of an Active or Candidate Set; means for identifying for each member of said union, said received pilot signals which include said member in their respective fixed, predetermined neighbor lists; means for calculating for each of said members, a relative signal strength based upon the number and signal strength of said received pilot signals which include said member in their respective fixed, predetermined neighbor lists; means for sorting said members based upon said relative signal strength; and means for selecting said members with the highest relative signal strengths to be included in a Neighbor List Update Message provided to said mobile station (18)
Claim 3
Dependent Claim
123 words
The apparatus of claim 2 wherein the means for calculating relative signal strength for each of said members operate in accordance with the equation: W k = ∑ j { f P j ; RTD j < RTD_MAX 0 ; RTD j > RTD_MAX where Pj is equal to the signal strength of said received pilot j, f(Pj) is a function of the signal strength of said received pilot j, RTDj is the round trip delay of said pilot j, Wk is the relative signal strength of member k in said union, RTD_MAX is a pre-determined maximum round trip delay threshold, and {j} is the set of received pilots which include member k in their respective unique, predetermined list of neighboring base stations.
Claim 4
Dependent Claim
52 words
The apparatus of claim 3 wherein the means for calculating the function f(Pj) operate in accordance with the equation: f Pj = max Pj - T_BASE , 0 ; f Pj > 0 where Pj is the signal strength of received pilot j and T_BASE is a predetermined minimum power threshold.
Claim 5
Dependent Claim
35 words
The apparatus of claim 3 wherein the means for calculating the function f(Pj) operate in accordance with the equation: f Pj = 10 Pj / 10 where Pj is the signal strength of pilot j.
Claim 6
Dependent Claim
54 words
The apparatus of claim 2 wherein the selecting means further comprise: means for removing from said union any of said members whose respective relative signal strength is not greater than a predetermined minimal threshold; and means for removing from said union members with the lowest relative signal strength, leaving a predetermined number of members.
Claim 7
Dependent Claim
17 words
The apparatus of claim 6 wherein said predetermined number of members is equal to at most twenty.
Claim 8
Independent Claim
121 words
A method of controlling handoff of a mobile station (18) from a first base station (12) to a second base station (14), the method comprising: monitoring the strength of pilot signals received by the mobile station from a plurality of base stations (12,14, 16) including the first and second base stations; receiving data from the mobile station (18) representing the strength and phase of the pilot signals received by the mobile station; and creating a ranked list of neighboring base stations to the mobile station (18), the ranked list depending on the strength of each pilot signal received by the mobile station and the number of times that a base station is found as a neighbor of each pilot signal received.
Claim 9
Dependent Claim
181 words
The method of claim 8 wherein the creating step further comprises the steps of: retrieving, from a memory unit (32), a fixed, predetermined neighbor list for each of said pilot signals that said mobile station (18) is presently communicating with and whose corresponding round trip delay time does not exceed a predetermined threshold; generating (60) an union of neighboring base stations from said fixed, predetermined neighbor lists; removing (65) from said union any member of said union which is a member of an Active or Candidate Set; identifying (70), for each member of said union, said received pilot signals which include said member in their respective fixed, predetermined neighbor lists; calculating (75), for each of said members, a relative signal strength based upon the number and signal strength of said received pilot signals which include said member in their respective fixed, predetermined neighbor lists; sorting (95) said members based upon said relative signal strength; and selecting (100, 105) said members with the highest relative signal strengths to be included in said Neighbor List Update Message provided to said mobile station (18).
Claim 10
Dependent Claim
125 words
The method of claim 9 wherein the step of calculating relative signal strength for each of said members is done in accordance with the equation: W k = ∑ j { f P j ; RTD j < RTD_MAX 0 ; RTD j > RTD_MAX where Pj is equal to the signal strength of said received pilot j, f(Pj) is a function of the signal strength of said received pilot j, RTDj is the round trip delay of said pilot j, W k is the relative signal strength of member k in said union, RTD_MAX is a pre-determined maximum round trip delay threshold, and {j} is the set of received pilots which include member k in their respective unique, predetermined list of neighboring base stations.
Claim 11
Dependent Claim
49 words
The method of claim 10 wherein the function f(Pj) is calculated in accordance with the equation: f Pj = max Pj - T_BASE , 0 ; f Pj > 0 where Pj is the signal strength of received pilot j and T_BASE is a predetermined minimum power threshold.
Claim 12
Dependent Claim
32 words
The method of claim 10 wherein the function f(Pj) is calculated in accordance with the equation: f Pj = 10 Pj / 10 where Pj is the signal strength of pilot j.
Claim 13
Dependent Claim
55 words
The method of claim 9 wherein the selecting step further comprises the steps of: removing from said union any of said members whose respective relative signal strength is not greater than a predetermined minimal threshold (100); and removing from said union members with the lowest relative signal strength, leaving a predetermined number of members (105).
Claim 14
Dependent Claim
18 words
The method of claim 13 wherein said predetermined number of members is equal to at most twenty (105).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.