Radio communication apparatus and method for radio communication

• US 6,542,759 B1
• Filed: 08/23/2000
• Issued: 04/01/2003
• Est. Priority Date: 06/14/1997
• Status: Expired due to Fees

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Vertex Standard LMR, Inc. (Motorola Solutions, Inc.)
• Inventors: Takei, Hideo, Fujiki, Shiro
• Primary Examiner(s): Le, Thanh Cong
• Application Number:
  US09/644,627
• Time in Patent Office: 951 Days
• Field of Search: 455/421, 455/73, 455/88, 455/97, 455/575, 455/62, 455/63, 455/67.1, 455/67.7, 455/404
• US Class Current: 455/575.1
• CPC Class Codes: G08B 27/008 with transmission via TV or radio broadcast
• CPC Class Codes: H04B 1/034 Portable transmitters

Abstract

A radio communication apparatus has a switch for indicating occurrence of emergency, a speaker, a speaker driver for emitting an alarm sound by driving said speaker in response to the operation of the switch, and a transmitter for transmitting a predetermined alarm signal by radio. When an emergency condition occurs to an owner of the radio communication apparatus, the radio communication apparatus emits an alarm sound from the speaker and emits an alarm signal by radio in response to a switching operation. Therefore, a person a short-distance away will be informed of an emergency by sound, and a person a long-distance away will be received by using a radio.

Claims

1. A radio communication apparatus, comprising;

a switch which is operable by a user;

a transmitter for transmitting a predetermined code one time with a first frequency in response to the operation of said switch when said switch is operated while in communication with another radio communication apparatus with said first frequency, and for then transmitting said predetermined code with a second frequency which is different from said first frequency; and

a receiver for changing a reception frequency to said second frequency when a predetermined code is received while in communication with said another radio communication apparatus using said first frequency.

2. A radio communication apparatus, comprising:

an emergency switch, which is operable by a user, for indicating occurrence of emergency;

memory for storing a control code indicating occurrence of emergency;

transmission means for reading out said control code from said memory by the operation of said emergency switch, and transmitting said control code with a previous transmission frequency;

means for changing the transmission frequency of said transmission means to an emergency communication frequency after transmission of said control code; and

reception means for receiving a radio signal and changing a call frequency to the emergency communication frequency upon detection of the control code in the received signal.

3. The radio communication apparatus according to claim 2, further comprising means for measuring a suspension period of time of communication with the emergency communication frequency and returning the emergency communication frequency to a previous transmission frequency when the suspension period of time exceeds a predetermined period.

4. The radio communication apparatus according to claim 2, wherein:

said transmission means transmits a signal containing a discrimination code assigned thereto in response to the operation of said emergency switch with the emergency communication frequency; and

said reception means discriminates whether or not a suspension period of the received signal exceeds a fixed period of time, and when said reception means discriminates if the suspension period of the received signal exceeds the fixed period of time, said reception means returns the emergency communication frequency to the previous call frequency.

5. The radio communication apparatus according to claim 2, wherein said control code is a control code based on one of CTCSS, MSK, DCS, DTMF, 2TONE and 5TONE.

6. A method for changing a communication frequency in case of emergency while at least two radio communication apparatuses, including first and second radio communication apparatuses, are communicating with each other using a first communication frequency and when a predetermined switch with which said first radio communication apparatus is equipped is operated, said method comprising steps of:

transmitting a predetermined code one time with said first frequency from said first radio communication apparatus, and then transmitting a predetermined code with a second frequency for emergency communication from said first radio communication apparatus receives a predetermined code transmitted from said first radio communication apparatus; and

making said second radio communication apparatus change the reception frequency to said second frequency when said second radio communication apparatus receives the predetermined code transmitted with said first frequency from said first radio communication apparatus.