Portable telephone set and communicative base station switching system

• US 20020032033A1
• Filed: 05/30/2001
• Published: 03/14/2002
• Est. Priority Date: 05/31/2000
• Status: Active Grant

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Tamukai, Kiyoshi
• Granted Patent: US 6,931,250 B2
• Time in Patent Office: Days
• 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 the 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 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; 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 are either two adjacent base stations or two adjacent but one base stations or two adjacent but 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:

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

a step 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 the first time is switched over to one of the neighbor base stations;

a step for comparing 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; and

a step 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.

6. A communicative base station switching system of a portable terminal for switching a communicative base station while in motion comprising:

a base station memory section for storing base station position data;

a base station position comparing section for receiving position data from a global positioning system of a mobile body and obtaining and comparing the distances of the base stations from the portable terminal by using the received position data as the position data of the portable terminal; and

a base station frequency switching section for switching the communicative base station of the portable terminal to the neighbor base station closest to the portable terminal according to the result of comparison in the base station position comparing section.

7. A communicative base station switching system of a portable terminal for switching a communicative base station while in motion in which base station position data and the portable terminal position data are obtained, the distances of the base stations from the portable terminal are obtained on the basis of the obtained position data, and the communicative base station of the portable terminal is switched to the neighbor base station closest to the portable terminal.