Paging system with spacial, frequency and time diversity

• US 7,023,832 B2
• Filed: 07/12/2002
• Issued: 04/04/2006
• Est. Priority Date: 11/27/1985
• Status: Expired due to Fees

• Current Assignee: Protocol-ip.com, LLC
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Ragan, Lawrence, Gaskill, Garold B.
• Primary Examiner(s): Holloway, III, Edwin C.
• Application Number:
  US10/193,892
• Publication Number:
  US 20030007477A1
• Time in Patent Office: 1,362 Days
• Field of Search: 370/345, 370/458, 370/311, 370/330, 340/7.2, 340/7.27, 340/7.42, 340/7.43, 455/455, 375/267, 714/777
• US Class Current: 370/345
• 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

A highly reliable radio paging system with 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 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 provide a highly reliable radio paging system.

Claims

1. A message transmission system comprising in combination,

a plurality of transmitters, the signals from which, at least in part, are transmitted to a particular local area, each of said transmitters operating at a different frequency, said transmitters transmitting messages according to a time slot protocol, each of said transmitters transmitting the same message multiple times in a time offset fashion,

a plurality of addressable radio receivers, located is said particular local area, said receivers being frequency agile and operating according to said time slot protocol, each receiver having an assigned time slot,

each receiver being first set to the frequency of one of said transmitters and switching to the frequency of a second one of said transmitters if a message packet is not received in the receiver'"'"'s assigned time slot,

whereby said transmission system has time, and frequency diversity.

2. The system recited in claim 1 wherein said messages are transmitted on an FM sub-carrier.

3. The system recited in claim 1 wherein said transmitters are at different physical locations, thereby providing spacial diversity.

4. The system recited in claim 1 wherein each message is sent repeatedly at different times.

5. The system recited in claim 1 wherein said time slot protocol includes repeating frames each of which have 64 sub-frames and wherein each of said sub-frames has 1027 time slots.

6. A system for transmitting the same message multiple times from a transmitter system transmitting messages to a particular local area and to a receiving device located in said particular local area comprising,

means for providing spacial diversity in the transmission paths between said transmitter system and said receiver, for different transmissions of said message in said particular local area,

means for providing time diversity in the transmission path between said transmitter system and said receiver, for different transmissions of said message in said particular local area,

means for providing frequency diversity in a transmission path between said transmitter system and said receiver, for different transmissions of said message in said particular local area,

whereby highly reliable transmissions are possible between said transmitter system and said receiver system.

7. The system recited in claim 6 whereby said messages are transmitted on an FM sub-carrier.

8. The system recited in claim 6 wherein said system operates according to a time slot protocol.

9. The system recited in claim 6 wherein said system operates according to a time slot protocol that includes repeating frames each of which has 64 sub-frames and wherein each of said sub-frames has 1027 time slots.

10. The system recited in claim 6 wherein said messages are transmitted on an FM sub-carrier and said system operates according to a time slot protocol that includes repeating frames each of which has 64 sub-frames and wherein each of said sub-frames has 1027 time slots.

11. A system for sending the same messages multiple times from a transmitter system to a receiving device, both located in a local area, said, system comprising,

means for providing spacial diversity in the transmission path between said transmitter system and said receiver, by having a plurality of transmitters at different physical locations in said local area, each of which transmit the same messages,

means for providing time diversity in the transmission path between said transmitter system and said receiver, by transmitting each message a plurality of times in a time offset fashion, and

means for providing frequency diversity in the transmission path between said transmitter system and said receiver, by having each of said transmitters operating at a different frequency,

whereby highly reliable transmissions are possible between said transmitter system and said receiver system.

12. The system recited in claim 11 wherein said messages are transmitted using FM sub-carrier.