Radio pager reporting frequency band information

• US 5,877,701 A
• Filed: 09/24/1996
• Issued: 03/02/1999
• Est. Priority Date: 09/26/1995
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nagakura, Tomio
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): WILSON JR, WILLIAM HALL
• Application Number:
  US08/718,844
• Time in Patent Office: 889 Days
• Field of Search: 340/825.44, 340/825.03, 340/311.1, 340/825.69, 455/71, 455/161.2, 455/166.2, 455/186.1, 455/185.1, 455/161.1, 455/165.1, 455/255, 455/32.1, 455/526, 455/517, 455/575, 455/434, 455/75, 455/76, 455/182.1 , 455/183.1, 455/260, 455/160.1, 455/183.2, 455/195.1, 331/25, 334/16, 370/310, 370/312, 370/313, 370/314, 1/1
• US Class Current: 340/7.42
• CPC Class Codes: H04W 8/245 from a network towards a terminal
• CPC Class Codes: H04W 88/022 Selective call receivers

Abstract

A radio pager of the present invention includes a non-volatile memory storing frequency information for each of a plurality of frequency bands for the confirmation of a frequency band. The frequency information are sequentially read out of the memory while frequency signals respectively corresponding to the information are sequentially fed to a frequency synthesizer, until frequency lock is detected. The frequency band to which the locked frequency belongs is determined to be the frequency band assigned to the radio pager and is reported to the operator. Therefore, even before frequency information for allowing the synthesizer to output a desired oscillation frequency corresponding to a receipt frequency is written to the pager and when a frequency band particular to the pager is not labeled on the pager body, the operator can see the frequency band easily. This prevents the operator from writing frequency information in the ROM of an inadequate radio pager to which a desired frequency band is not assigned.

Claims

1. A radio pager adaptive to a plurality of frequency bands for identifying and reporting to a user a frequency band assigned to the radio pager before frequency information for producing a desired oscillation frequency corresponding to a reception frequency has been stored in the radio pager by an external source, said radio pager comprising:

a radio section including a frequency synthesizer adaptive to a particular frequency band;

a non-volatile memory for storing frequency information for confirmation for each of a plurality of frequency bands;

frequency lock detecting means for determining whether the oscillation frequency of said frequency synthesizer has been locked at a frequency corresponding to a frequency signal input to said frequency synthesizer; and

control means for determining and reporting to a user a frequency band assigned to the radio pager before frequency information for producing a desired oscillation frequency corresponding to a reception frequency has been stored in the radio pager by an external source, said control means sequentially reading said frequency information of the plurality of frequency bands from said non-volatile memory and providing said frequency signal representative of said frequency information to said frequency synthesizer until said frequency lock detecting means detects that the oscillation frequency of said frequency synthesizer has been locked in response to said frequency signal, and reporting the frequency band to which the lock frequency belongs as the frequency band assigned to the radio pager.

2. A radio pager as claimed in claim 1, wherein to determine if the frequency has been locked, said frequency lock detecting means determines whether the phases of a frequency-divided reference oscillation frequency and a frequency-divided output oscillation signal are fully coincident.

3. A radio pager as claimed in claim 1, wherein to determine if the frequency has been locked, said frequency lock detecting means determines whether a control voltage input to a VCO, which oscillates at a frequency corresponding to said control voltage, is coincident with a preselected value.

4. A radio pager as claimed in claim 3, wherein said nonvolatile memory stores two channels of frequency information for each of the plurality of frequency bands, one channel being higher than a center frequency of the respective frequency band and the other channel being lower than said center frequency, and wherein said frequency lock detecting means determines whether the control voltage input to said VCO is higher or lower than a voltage corresponding to when the frequency is locked at the center frequency of a preselected one of the frequency bands, and wherein said control means determines, when said frequency lock detecting means detects both a value higher than said voltage and a value lower than said voltage in response to said two channels of frequency information of a same frequency band, that said frequency band is a frequency band assigned to said radio pager.