Portable telephone set and communicative base station switching system

• US 6,931,250 B2
• Filed: 05/30/2001
• Issued: 08/16/2005
• Est. Priority Date: 05/31/2000
• Status: Expired due to Fees

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Tamukai, Kiyoshi
• Primary Examiner(s): Tran, CongVan
• Application Number:
  US09/866,714
• Publication Number:
  US 20020032033A1
• Time in Patent Office: 1,539 Days
• Field of Search: 455436-440, 455/403, 455/404.2, 455/435.2, 455/456.1, 455/456.3, 34235706-35707, 342/357.12
• US Class Current: 455/437
• CPC Class Codes: H04W 36/322 by location data

Abstract

A received electric field measuring section 11 measures the received electric fields from the communicative base station and the neighbor base stations. A received electric field memory section 12 stores received electric field patterns of the communicative base station and two given neighbor stations measured in the received electric field measuring section whenever the communicative base station for communication for the first time is switched over to one of the neighbor base stations. A received electric field pattern comparing section 13 compares the received electric field patterns of the communicative base station having and the two given neighbor stations and the received electric field patterns stored in the received electric field memory section whenever the received electric fields from the communicative base station been in communication with before and the two given neighbor base stations are measured in the received electric field measuring section. A base station position acquiring and switching means 14 and 15 acquires the position of a neighbor station, which the portable terminal is moving toward, in correspondence to a stored received electric field, which is found in the received electric field pattern comparing section to be identical in pattern with a measured received electric field, and switching the communicative base station over to the pertinent neighbor base station.

Claims

1. A communicative base station switching system of a portable terminal for switching a communicative base station to neighbor base stations while in motion comprising:

a received electric field measuring section for measuring the received electric fields from the communicative base station and the neighbor base stations;

a received electric field memory section for storing received electric field patterns of the communicative base station and two given neighbor stations measured in the received electric field measuring section whenever the communicative base station for communication for a first time is switched over to one of the neighbor base stations;

a received electric field pattern comparing section for comparing the received electric field pattern of the communicative base station and the two given neighbor stations and the received electric field patterns stored in the received electric field memory section whenever the received electric fields from the communicative base station having been in communication with the portable terminal before and the two given neighbor base stations are measured in the received electric field measuring section; and

a base station position acquiring and switching means for acquiring the position of a neighbor station, which the portable terminal is moving toward, in correspondence to a stored received electric field, which is found in the received electric field pattern comparing section to be identical in pattern with a measured received electric field, and switching the communicative base station over to the pertinent neighbor base station.

2. The communicative base station switching system according to claim 1, wherein when the portable terminal communicates with the communicative base station for the first time, the received electric field pattern comparing section executes the comparison after the received electric field patterns of all the plurality of neighbor base stations have been stored in the received electric field comparing section by switching the communicative base station over to the neighbor base stations.

3. The received base station switching system according to claim 1, wherein when the portable terminal communicates with the communicative base station for the first time while the received electric field patterns of all the plurality of neighbor base stations have not been stored in the received electric field comparing section by switching the communicative base station over to the neighbor base stations, the received electric field measuring section executes the received electric field measurement for switching the communicative base station over to the neighbor base station of the maximum received electric field intensity.

4. The communicative base station switching system according to claim 1, wherein the two given neighbor base stations comprise at least one of two adjacent base stations, two adjacent base stations that are separated by one base station, and two adjacent base stations that are separated by two base stations.

5. A communicative base station switching method of a portable terminal for switching a communicative base station to neighbor base stations while in motion, comprising:

measuring the received electric fields from the communicative base station and the neighbor base stations;

storing received electric field patterns of the communicative base station and two given neighbor stations measured in the received electric field measuring section whenever the communicative base station for communication for the first time is switched over to one of the neighbor base stations;

comparing the received electric field patterns of the communicative base station and the two given neighbor stations and the received electric field patterns stored in the received electric field memory section whenever the received electric fields from the communicative base station having been in communication with the portable terminal before and the two given neighbor base stations are measured in the received electric field measuring section; and

acquiring the position of a neighbor station, which the portable terminal is moving toward, in correspondence to a stored received electric field, which is found in the received electric field pattern comparing section to be identical in pattern with a measured received electric field, and switching the communicative base station over to the pertinent neighbor base station.

6. The communicative base station switching method according to claim 5, further comprising determining whether the portable terminal previously communicated with the communicative base station.

7. A communicative base station switching system of a portable terminal for switching a communicative base station to neighbor base stations while in motion, comprising:

a measuring section for measuring electric field patterns from the communicative base station and a plurality of neighbor base stations;

a memory section for storing the electric field patterns of the communicative base station and two of the plurality of neighbor stations measured in the measuring section, when the communicative base station for communicating with the portable terminal has not been in previous communication with the portable terminal, and when the communicative base station for communicating with the portable terminal is switched over to one of the neighbor base stations;

a comparing section for comparing the electric field patterns of the communicative base station and the two neighbor stations received by the measuring section with the electric field patterns stored in the memory section, when the communicative base station has been in previous communication with the portable terminal, and when the communicative base station and the two neighbor base stations are measured in the measuring section; and

a position acquiring and switching section for acquiring a position of a neighbor station, which the portable terminal is moving toward, based on an electric field pattern stored in the memory section which is found in the comparing section to be identical to an electric field pattern measured by the measuring section, and switching the communicative base station to a pertinent neighbor base station.

8. A communicative base station switching method of a portable terminal for switching a communicative base station to neighbor base stations while in motion, comprising:

determining whether the portable terminal previously communicated with the communicative base station;

measuring electric field patterns from the communicative base station and a plurality of neighbor base stations;

storing the electric field patterns of the communicative base station and two of the plurality of neighbor stations when the portable terminal has not previously communicated with the communicative base station and when the communicative base station is switched over to one of the neighbor base stations;

comparing the electric field patterns of the communicative base station and the at least two of the plurality of neighbor stations with stored electric field patterns when the communicative base station previously communicated with the portable terminal and when the electric field patterns of the communicative base station and the at least two of the plurality of neighbor base stations are measured; and

acquiring the position of a neighbor station that the portable terminal is moving toward, based on a stored electric field pattern, which is determined to be identical with a measured electric field pattern, and

switching the communicative base station to said neighbor base station in which the stored electric field pattern is determined to be identical to a measured electric field pattern.

9. A communicative base station switching system of a portable terminal for switching a communicative base station to neighbor base stations while in motion, comprising:

means for measuring electric field patterns from the communicative base station and a plurality of neighbor base stations;

means for storing the electric field patterns of the communicative base station and two of the plurality of neighbor stations measured in the means for measuring, when the communicative base station for communicating with the portable terminal has not been in previous communication with the portable terminal, and when the communicative base station for communicating with the portable terminal is switched over to one of the neighbor base stations;

means for comparing the electric field patterns of the communicative base station and the two neighbor stations received by the means for measuring with the electric field patterns stored in the means for storing, when the communicative base station has been in previous communication with the portable terminal, and when the communicative base station and the two neighbor base stations are measured in the means for measuring; and

means for acquiring a position of a neighbor station, which the portable terminal is moving toward, based on an electric field pattern stored in the means for storing which is found in the means for comparing to be identical to an electric field pattern measured by the means for measuring, and

means for switching the communicative base station to said neighbor base station that the portable terminal is moving toward.

10. A communicative base station switching system of a portable terminal for switching a communicative base station to neighbor base stations while in motion comprising:

a measuring section for measuring power levels of the communicative base station and the neighbor base stations and for determining whether the portable terminal has previously communicated with the communicative base station;

wherein, if the portable terminal has not previously communicated with the communicative base station, said measuring section measures power levels of the communicative base station and the neighbor base stations; and

wherein, if the portable terminal has previously communicated with the communicative base station, said measuring section selects two neighbor base stations and measures power levels of said two neighbor base stations and the communicative base station;

a memory section for storing power levels measured by the measuring section when the communicative base station is switched to a neighbor station;

a comparing section for comparing the power levels of the selected two neighbor base stations measured by the measuring section with the power levels of the neighboring base stations stored in the memory section, and determining whether a power level measured by the measuring section is identical to a power level stored in the memory section; and

a switching section for switching from the communicative base station to a corresponding neighbor base station when the power level measured by the measuring section is identical to the power level stored in the memory section.