Digital cordless telephone device which gives a warning to prevent unexpected termination of communication

• US 6,556,822 B1
• Filed: 06/27/1996
• Issued: 04/29/2003
• Est. Priority Date: 06/30/1995
• Status: Expired due to Fees

• Current Assignee: Kyocera Corporation
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsumoto, Hirotsugu
• Primary Examiner(s): Kincaid, Lester G.
• Application Number:
  US08/671,558
• Time in Patent Office: 2,497 Days
• Field of Search: 455/421, 455/422, 455/423, 455/425, 455/426, 455/465, 455/436, 455/437, 455/442, 455/444, 455/566, 455/567, 455/67.1, 455/67.3, 455/67.7, 455/74.1, 455/575
• US Class Current: 455/421
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data

Abstract

A digital cordless telephone device for performing radio communication with another telephone device via one of a plurality of base stations and executing a hand-over between a first base station to a second base station based on the RSSI of the first base station. The digital cordless telephone device includes an RSSI detection unit for detecting the RSSI of the first base station, a comparison unit for comparing the RSSI detected by the RSSI detection unit with a predetermined threshold, a connection control unit for trying to execute a hand-over when the RSSI is smaller than the predetermined threshold, a measurement unit for counting the number of continuous hand-over failures, and an information unit for giving a warning to the user of the digital cordless telephone device when the number counted by the measurement unit has reached the predetermined threshold.

Claims

1. A digital cordless telephone device which performs radio communication with another telephone device via one of a plurality of base stations and executes a hand-over, the hand-over signifying said digital cordless telephone device switching its connection from a first base station to a second base station based on an RSSI of the first base station, said digital cordless telephone device comprising:

an RSSI detection means for detecting the RSSI of the first base station;

a comparison means for comparing the RSSI detected by said RSSI detection means with a predetermined threshold;

a connection control means for trying to execute a hand-over when the RSSI is smaller than the predetermined threshold;

a measurement means for counting a number of continuous hand-over failures; and

an information means for giving a warning to a user of said digital cordless telephone device when the number counted by said measurement means has reached the predetermined threshold.

2. The digital cordless telephone device of claim 1, wherein said connection control means comprises:

a disconnection means for disconnecting said digital cordless telephone device from the first base station when the RSSI is smaller than the predetermined threshold;

a search means for searching for the second base station when said disconnection means has disconnected said cordless telephone device from the first base station;

a hand-over means for executing a hand-over when said search means has searched for the second base station;

a re-connection means for trying to re-connect said digital cordless telephone device with the first base station, when the second base station does not exist; and

a judgement means for judging a hand-over to have ended in failure when said re-connection means has successfully re-connected said digital cordless telephone device with the first base station.

3. The digital cordless telephone device of claim 2, wherein said judgement means comprises:

a first judgement unit for judging whether said re-connection means has successfully re-connected said digital cordless telephone device with the first base station; and

a second judgement unit for judging whether the RSSI of the first base station is smaller than the predetermined threshold when said first judgement unit has judged that said digital cordless telephone device has been successfully re-connected with the first base station,

wherein said judgement means judges a hand-over to have ended in failure when said second judgement unit has judged the RSSI of the first base station to be smaller than the predetermined threshold.

4. The digital cordless telephone device of claim 3, wherein said measurement means comprises:

a counter for counting a number of hand-over failures which have been judged by said judgement means,

wherein said measurement means resets said counter when said hand-over means has successfully executed a hand-over and when said second judgement unit has judged the RSSI of the first base station to be one of being equal to and larger than the predetermined threshold.

5. The digital cordless telephone device of claim 2, wherein said search means comprises:

a detection unit for detecting RSSIs of said plurality of base stations except the first base station; and

a judgement unit for judging a presence or absence of the second base station from the RSSIs detected by said detection unit.

6. The digital cordless telephone device of claim 1, wherein said comparison means comprises:

a storage unit for storing the predetermined threshold.

7. The digital cordless telephone device of claim 6 further comprising:

a reception means for receiving the predetermined threshold from the first base station,

wherein said storage unit stores the predetermined threshold received by said reception means.

8. The digital cordless telephone device of claim 1, wherein said information means sounds a beep as the warning through a speaker.

9. The digital cordless telephone device of claim 1, wherein said information means sounds the beep when the number of hand-over failures counted by said measurement means has become two.

10. A digital cordless telephone device which performs radio communication with another telephone device via one of a plurality of base stations and executes a hand-over, the hand-over signifying said digital cordless telephone device switching its connection from a first base station to a second base station based on an RSSI of the first base station, said digital cordless telephone device comprising:

an RSSI detection means for detecting RSSIs of said plurality of base stations;

a comparison means for comparing an RSSI of the first base station which has been detected by said RSSI detection means with a predetermined threshold;

a search means for searching for all base stations that can be a target station for re-connection when the RSSI of the first base station is smaller than the predetermined threshold, and for selecting one base station among said all base stations;

a measurement means for counting a number of times said search means has selected the first base station continuously; and

an information means for giving a warning to a user of said digital cordless telephone device when the number counted by said measurement means has reached the predetermined threshold.

11. The digital cordless telephone device of claim 10, wherein said comparison means comprises:

a storage unit for storing the predetermined threshold.

12. The digital cordless telephone device of claim 11 further comprising:

a reception means for receiving the predetermined threshold from the first base station,

wherein said storage unit stores the predetermined threshold received by said reception means.

13. The digital cordless telephone device of claim 10, wherein said measurement means comprises:

a counter for counting a number of times said search means has selected the first base station;

wherein said measurement means resets said counter when base stations other than the first base station have been selected.

14. The digital cordless telephone device of claim 13, wherein said measurement means resets said counter when said search means has selected the first base station and the RSSI of the first base station is one of being equal to and larger than the predetermined threshold.

15. The digital cordless telephone device of claim 10, wherein said one base station that is selected among said all base stations has a highest RSSI among the RSSIs detected by said RSSI detection means.

16. The digital cordless telephone device of claim 15, wherein when said search means selects said one base station, said search means disconnects said digital cordless telephone device from the first base station.

17. The digital cordless telephone device of claim 10, wherein said information means sounds a beep as the warning through a speaker.

18. The digital cordless telephone device of claim 10, wherein said information means sounds the beep when the number of hand-over failures counted by said measurement means has become two.