Paging system with spacial, frequency and time diversity

• US 6,433,668 B1
• Filed: 12/09/1994
• Issued: 08/13/2002
• Est. Priority Date: 05/25/1990
• Status: Expired due to Term

• Current Assignee: Cufer Asset Ltd LLC (Intellectual Ventures LLC), Seiko Instruments Incorporated (Seiko Group)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Ragan, Lawrence, Gaskill, Garold B.
• Primary Examiner(s): Holloway, III, Edwin C.
• Application Number:
  US08/353,572
• Time in Patent Office: 2,804 Days
• Field of Search: 340/825.44, 340/7.2, 340/7.27, 340/7.42, 340/7.43, 370/311, 370/330, 455/455
• US Class Current: 340/7.27
• CPC Class Codes: G04G 21/04 using radio waves radio-controlled time-pieces G04R
• CPC Class Codes: G08B 3/1016 using wireless transmission calling systems using transmission by inductive loop H04B5/00
• CPC Class Codes: G08B 3/1066 with other provisions not elsewhere provided for, e.g. turn-off protection
• CPC Class Codes: G08B 5/222 Personal calling arrangements or devices, i.e. paging systems selective calling systems and call receivers H04W84/00, H04W68/00
• CPC Class Codes: G08B 5/223 using wireless transmission
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 84/022 One-way selective calling networks, e.g. wide area paging
• CPC Class Codes: H04W 88/022 Selective call receivers
• CPC Class Codes: H04W 88/026 using digital address codes
• CPC Class Codes: H04W 88/185 Selective call encoders for paging networks, e.g. paging centre devices
• CPC Class Codes: H04W 88/187 using digital or pulse address codes
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention provides a highly reliable radio paging system. The radio paging system of the present invention provides a combination of time, frequency and spacial diversity in order to increase the reliability of the system. Time diversity is provided by broadcasting the same message at a number of different times. Spacial diversity is achieved by broadcasting the same message from a number of different locations. Frequency diversity is achieved by broadcasting the same message at a number of different frequencies. The paging receiver according to the present invention is designed to receive messages on a number of different frequencies; however, the pager only responds to a message the first time that it receives the particular message. The combination of time, frequency, and spacial diversity provided by the present invention results in a highly reliable radio paging system.

Claims

1. A message transmission system comprising in combination,

first and second transmitters located at different physical locations, said first transmitter operating at a first frequency and said second transmitter operating at a second frequency which is different than said first frequency, each of said transmitters transmitting the same messages at different times,

a plurality of radio receivers, said receivers being frequency agile,

means for setting a receiver to said first frequency and for switching to the frequency of said second transmitter if a message is not received from said first transmitter,

whereby said transmission system has time, space and frequency diversity.

2. The system recited in claim 1 wherein said transmitters transmit information on an FM subcarrier.