Synchronous receiving method for selective calling signal

• US 4,802,240 A
• Filed: 07/01/1987
• Issued: 01/31/1989
• Est. Priority Date: 07/03/1986
• Status: Expired due to Term

• Current Assignee: Kokusai Denki Kabushiki Kaisha
• Original Assignee: Kokusai Denki Kabushiki Kaisha
• Inventors: Yamaguchi, Hiroyuki, Yokoyama, Naomi
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Kuntz, Curtis A.
• Application Number:
  US07/068,656
• Time in Patent Office: 580 Days
• Field of Search: 455/343, 455/228, 455/229, 455/127, 455/38, 340/825.06, 340/825.44, 340/825.53, 340/825.48, 340/311.1
• US Class Current: 340/7.32
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 88/022 Selective call receivers
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A synchronous receiving method for a selective calling signal is disclosed, in which the selective calling signal comprises a first code of predetermined format which enables a receiving unit to easily detect that information is being sent over a channel, a second code of a predetermined format which succeeds the first code and causes the receiving unit to be synchronized with the information transmitted over the channel, and a third code which succeeds the second code and sends information to the receiving unit. In accordance with the present invention, the synchronization is established with the third code in place of the second code included in the transmitted signal to settle the problems of impaired battery saving efficiency, decreased amount of information and increased transmitting time.

Claims

1. A synchronous receiving method for a selective calling signal, which detects by a receiving unit first, second and third codes of a received information signal of a predetermined code format, and for enhancing the battery saving efficiency of the receiving unit, comprising the steps of:

intermittently operating the receiving unit for a fixed short period of time at regular time interval by turning ON and OFF power supply to the receiving unit under control of a timing control circuit in the receiving unit, before the detection of the first code for indicating that information is being sent on a channel;

continuing the operating of the receiving unit for a fixed period of time, during which a just preceding one of the second codes is detected as a synchronizing code, after the detection of the first code;

intermittently receiving and detecting by the receiving unit third codes of information, the position of which is determined by a selective calling number sent between adjacent two of the second codes and assigned to the receiving unit, at intervals determined by a self-identification memory in the receiving unit, without causing the receiving unit to receive and detect the second codes which are sent after the just preceding one of the second codes at regular intervals in the time interval between the detection of the just preceding one of the second codes and the detection of a next one of the first codes and utilizing the third codes for deciding whether the receiving unit is synchronized with the transmitted signal of the channel.

2. A synchronous receiving method for a selective calling signal, which detects by a receiving unit first, second and third codes of a received information signal of a predetermined code format, and for enhancing the battery saving efficiency of the receiving unit, comprising the steps of:

intermittently operating the receiving unit for a fixed short period of time at regular time interval by turning ON and OFF power supply to the receiving unit under control of a timing control circuit in the receiving unit, before the detection of the first code for indicating that information is being sent on a channel;

continuing the operation of the receiving unit for a fixed period of time, during which a just preceding one of the second codes is detected as a synchronizing code, after the detection of the first code;

intermittently receiving and detecting by the receiving unit a newly transmitted signal starting with the first code, by an intermittent power supply operation whereby the receiving unit is actuated in synchronism with the period of the second codes transmitted at regular intervals after the most preceding one of the second codes and for a period of time long enough to detect the first code and shorter than the time for detecting each second code, in the time intervals between the detection of the just preceding on of the second codes and the detection of the next one of the first codes;

intermittently received and detecting, at intervals determined by a self-identification memory in the receiving unit, the third code of information the position of which is determined between adjacent two of the second codes sent after the most preceding one of the second codes by a selective calling signal sent between the adjacent two of the second codes and assigned to the receiving unit; and

utilizing the third code for deciding whether the receiving unit is synchronizing with the transmitted signal of the channel.