Fixed subscriber unit

• US 6,314,270 B1
• Filed: 05/18/1998
• Issued: 11/06/2001
• Est. Priority Date: 05/23/1997
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Uchida, Osamu
• Primary Examiner(s): SMITS, TALIVALDIS IVARS
• Application Number:
  US09/080,287
• Time in Patent Office: 1,268 Days
• Field of Search: 379/413, 379/419, 455/572, 455/573, 455/67.1
• US Class Current: 455/67.7
• CPC Class Codes: H04W 52/0296 switching to a backup power supply
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A fixed subscriber unit includes a voltage measuring unit which acquires a DC input voltage value to be applied to a power circuit, and a comparator/judging unit which compares a preset DC voltage with the DC voltage measurement and judges whether the power circuit is driven by the DC voltage from an AC/DC adaptor or by the DC voltage supplied from a charge battery. When the power circuit is driven by the charge battery, the available operation time of the fixed subscriber unit is calculated by a calculation unit from the DC voltage measurement. The information thus obtained on the driving power state and/or the available operation time are aurally or visually notified to the user by a notification unit. The user thus can select an appropriate method of using the fixed subscriber unit according to the prevailing situation.

Claims

1. A fixed subscriber unit connected by wire means to at least one telephone set which has its power supplied from said fixed subscriber unit through said wire means, said fixed subscriber unit comprising:

a radio section for transmitting and receiving radio signals to and from a base station connected to a public telephone network;

a signal processing section for processing signals between said at least one telephone set and said radio section such that said at least one telephone set can communicate with another telephone set connected to said public telephone network;

a power back-up charge battery unit for being connected to an AC/DC adaptor, said AC/DC adaptor outputting a DC voltage when supplied with an electric power from an external AC power supply, wherein, when a DC voltage is being output by said adaptor, said power back-up charge battery unit supplies an output comprising said DC voltage while charging a battery of said power back-up charge battery unit, and when a DC voltage is not being supplied from said adaptor, said power back-up charge battery unit supplies an output comprising output power from said battery;

a power circuit for supplying electric power to each section of said fixed subscriber unit when connected to said power back-up charge battery unit;

voltage measuring means for measuring an output voltage of said power back-up charge battery unit;

comparator/determining means for comparing the measured voltage with a predetermined voltage and determining whether said power circuit is supplied with electric power from said external AC power supply through said power back-up charge battery unit or only from said power back-up charge battery unit;

ringing tone signal generating means for generating a ringing tone signal for notifying a user of said at least one telephone set of information regarding said power back-up charge battery unit, on the basis of a determination of said comparator/determining means; and

notification means for notifying said user of the information on said power back-up charge battery unit by sending said generated ringing tone signal to said at least one telephone set through said wire means.

2. A fixed subscriber unit according to claim 1, wherein said notification means comprises means for visually notifying the user as to whether said power circuit is supplied with electric power from said external AC power supply through said power back-up charge battery unit or only from said power back-up charge battery unit.

3. A fixed subscriber unit according to claim 1, further comprising:

calculation means for calculating an available operation time of said power back-up charge battery unit in the case where said power circuit is supplied with electric power only from said power back-up charge battery unit.

4. A fixed subscriber unit according to claim 3, wherein said notification means comprises means for visually notifying the user of said available operation time.

5. A fixed subscriber unit according to claim 3, wherein said notification means notifies the user of the available operation time by controlling at least one of a frequency and a period of generation of said ringing tone signal on the basis of a calculation result of said calculation means.

6. A fixed subscriber unit according to claim 4, wherein said predetermined tone is a dial tone.

7. A fixed subscriber unit according to claim 4, wherein said predetermined tone is a busy tone.

8. A fixed subscriber unit according to claim 3, wherein said notification means notifies the user of the available operation time as audio information by controlling a memory for storing the audio information, on the basis of a calculation result of said calculation means.

9. A fixed subscriber unit according to claim 1, wherein:

said wire means comprises two telephone wires; and

said fixed subscriber unit further comprises a two-wire/four-wire converting means for converting said two telephone wires to a total of four wires including two transmit wires and two receive wires, said total of four wires being connected to said radio