Method for dynamically changing control frames for selective call receiving devices

• US 5,923,266 A
• Filed: 01/23/1998
• Issued: 07/13/1999
• Est. Priority Date: 12/04/1995
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ayerst, Douglas I., Lin, Jyh-Han, Khan, Malik, Dorenbosch, Jheroen Pieter, Cannon, Gregory Lewis, Wang, Zhonghe, Choi, Kwok Keung, Nelson, Leonard
• Primary Examiner(s): Louis-Jacques, Jacques H.
• Assistant Examiner(s): Beaulieu, Yonel
• Application Number:
  US09/012,274
• Time in Patent Office: 536 Days
• Field of Search: 340/825.52, 340/825.44, 340/825.47, 340/825.22, 370/310, 370/3
• US Class Current: 340/7.39
• CPC Class Codes: H04W 88/026 using digital address codes
• CPC Class Codes: H04W 88/187 using digital or pulse address codes
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A selective call receiving device (10) such as a pager is controlled to dynamically change a base frame assigned to the device and subsequent control frames derived therefrom. The time that the device is operative to look for its address in a received signal can thus be dynamically changed to improve the efficiencies of a mixed systems environment without substantially reducing the battery life of the selective call receiving device (10). In two embodiments of the invention a new base frame for the device is derived from an originally assigned base frame that is stored in the selective call receiving device. In another embodiment, a new base frame for the device is derived from the device'"'"'s address along with frame management information that is received by the selective call receiving device.

Claims

1. A method for controlling a selective call receiving device having an associated system of a plurality of different systems sharing a frequency channel, said selective call receiving device having parameters assigned thereto including at least one assigned address and an assigned base frame and said method controlling said device to dynamically change the base frame assigned to the device, said assigned base frame determining a time that the device is operative to look for the device'"'"'s address in a received signal, the method comprising:

storing a first base frame assigned to said device and an address assigned to said device;

receiving a signal having control frame information and a reference frame identifying one of said different systems;

determining whether said reference frame identifies said associated system;

determining a step value from said control frame information when said received signal identifies said associated system; and

deriving a new base frame for said device in accordance with one of said assigned parameters, said reference frame and said step value to change the time that the device is operative to look for the device'"'"'s address in said received signal.

2. A method for controlling a selective call receiving device as recited in claim 1 wherein said new base frame is derived from said reference frame, said step value and said first base frame assigned to said device.

3. A method for controlling a selective call receiving device as recited in claim 1 wherein said new base frame is derived from said reference frame, said step value and said address assigned to said device.

4. A method for controlling a selective call receiving device as recited in claim 1 wherein said step of determining whether said reference frame identifies said associated system includes searching the frames of one or more channels until a frame is found that includes information identifying said associated system.

5. A method for controlling a selective call receiving device as recited in claim 4 wherein said information identifying the system that is associated with the device includes a system identification and a service provider identification.

6. A method for controlling a selective call receiving device as recited in claim 1 wherein said new base frame is determined by mod(RFN, SSS)+SHFN-mod(SHFN, SSS) where RFN is a number associated with said reference frame, SSS is said step value and SHFN is a number associated with said first base frame.

7. A method for controlling a selective call receiving device as recited in claim 1 wherein said reference frame includes information identifying a first possible base control frame and said step value represents the spacing between different base control frames for other devices in the same system as said device and said new base frame assigned to said device is derived from said first possible base control frame, said step value, and said device'"'"'s address.

8. A method for controlling a selective call receiving device having an associated system, at least one assigned address, and an assigned base frame, said method controlling said device to dynamically change the base frame assigned to the device, said assigned base frame determining a time that the device is operative to look for the device'"'"'s address in a received signal, the method comprising:

storing a first base frame assigned to said device;

receiving a signal having a reference frame identifying a system, said received signal including control frame information X and said reference frame having an associated reference frame number;

determining whether the received signal includes a reference frame identifying said associated system;

determining a step value from said control frame information X if said received signal identifies said associated system, said step value being represented by 2^X ;

modifying said first base frame in accordance with said reference frame number and said step value to derive a new base frame; and

determining in accordance with said step value a number of frames from which said new base frame is spaced to a next successive control frame that is assigned to said device.

9. A method for controlling a selective call receiving device as recited in claim 8 wherein said new base frame is determined by mod(RFN, SSS)+SHFN-mod(SHFN, SSS) where RFN is said reference frame number, SSS is said step value and SHFN is a number associated with said first base frame.

10. A method for controlling a selective call receiving device as recited in claim 8 wherein said device includes an assigned device collapse value that is stored in said device;

said received signal includes a system collapse value; and

said step of determining a number of frames from which the new base frame is spaced to a next successive control frame includes the steps of determining the minimum of the device collapse value and said system collapse value; and

determining the maximum of said minimum and said step value, said maximum representing the number of frames from which the new base frame is spaced to a next successive control frame.

11. A method for controlling a selective call receiving device having an associated system, an associated service provider, at least one assigned address and an assigned base frame, said method controlling said device to dynamically change the base frame assigned to the device, said assigned base frame determining a time that the device is operative to look for the device'"'"'s address in a received signal, the method comprising:

storing a first base frame assigned to said device;

detecting in the received signal a reference frame identifying one of a plurality of systems and a service provider and a plurality of frames transmitted by said one of the plurality of systems, said reference frame having a reference frame number;

determining whether said reference frame identifies said associated system;

measuring a step value from the spacing between frames transmitted by said one of the plurality of systems when said reference frame identifies said associated system and the service provider associated with said device; and

modifying said first base frame in accordance with said reference frame number and said step value to derive a new base frame.

12. A method for controlling a selective call receiving device as recited in claim 11 wherein said new base frame is determined by mod(RFN, SSS)+SHFN-mod(SHFN, SSS) where RFN is said reference frame number, SSS is said step value and SHFN is a number associated with said first base frame.

13. A method for controlling a selective call receiving device as recited in claim 11 including the step of determining in accordance with said step value a number of frames from which said new base frame is spaced to a next successive control frame that is assigned to said device.

14. A method for controlling a selective call receiving device as recited in claim 13 wherein said device includes an assigned device collapse value that is stored in said device;

said received signal includes a system collapse value; and

said step of determining a number of frames from which the new base frame is spaced to a next successive control frame includes the steps of determining the minimum of the device collapse value and said system collapse value and determining the maximum of said minimum and said step value, said maximum representing the number of frames from which the new base frame is spaced to a next successive control frame.

15. A method for controlling a selective call receiving device having an associated system, at least one assigned address, and an assigned base frame, said method controlling said device to dynamically change the base frame assigned to the device, said assigned base frame determining a time that the device is operative to look for the device'"'"'s address in a received signal, the method comprising:

storing a value representing a first base frame assigned to said device, said first base frame value being formed of a plurality of bits;

receiving information representing a system base frame mask X and a system base frame offset that is a number between 0 and 2^X -1; and

modifying said first base frame value with said base frame mask and said base frame offset to provide a new base frame to change the time that the device is operative to look for the device'"'"'s address in said received signal.

16. A method for controlling a selective call receiving device as recited in claim 15 wherein said modifying step includes the steps of replacing each of X least significant bits in said first base frame value with a zero;

and adding said base frame offset to provide said new base frame.

17. A method for controlling a selective call receiving device having an associated system of a plurality of different systems sharing a frequency channel, said selective call receiving device having parameters assigned thereto including at least one assigned address and an assigned base frame and said method controlling said device to dynamically change the base frame assigned to the device, said assigned base frame determining the time that the device is operative to look for the device'"'"'s address in a received signal, the method comprising:

storing a first base frame assigned to said device and an address assigned to said device;

receiving a signal having control information and a reference frame identifying one of said different systems;

determining whether said received signal identifies said associated system;

retrieving control frame information from said received signal when said received signal identifies said associated system, said control frame information including an identity of a first possible device control frame; and

deriving a new base frame for said device from information assigned to said device and from said first possible device control frame.

18. A method for controlling a selective call receiving device as recited in claim 17 wherein said new base frame is derived from the address assigned to said device and said first possible device control frame.

19. A method for controlling a selective call receiving device as recited in claim 17 wherein said control frame information includes a step value X and said method includes determining a subsequent control frame for said device based on said new base frame plus an integer times 2^X.

20. A method for controlling a selective call receiving device as recited in claim 19 wherein a plurality of control frames are grouped in a cluster for a plurality of selective call receiving devices and said control frame information includes a first distance value representing the distance between control frames within a cluster, said new base frame being derived from said information assigned to said device, said first possible device control frame and said first distance value.

21. A method for controlling a selective call receiving device as recited in claim 20 wherein said control frame information includes a second distance value representing the distance between control frames associated with one device in one cluster and said control frames for said one device are determined based upon said new base frame for said one device plus a first integer times 2^X plus a second integer times said second distance value.

22. A method for controlling a selective call receiving device as recited in claim 17 wherein said control frame information includes a value representing the number of systems in said plurality of different systems and said new base frame is derived from the address assigned to said device, said first possible device control frame and said value representing the number of systems in said plurality of different systems.

23. A method for controlling a selective call receiving device having an associated system, at least one assigned address, and an assigned base frame, said method controlling said device to dynamically change the base frame assigned to the device, said assigned base frame determining a time that the device is operative to look for the device'"'"'s address in a received signal, the method comprising:

storing a first base frame assigned to said device and an address assigned to said device;

receiving a signal having control information and a reference frame identifying a system;

determining whether the received signal identifies said associated system;

retrieving control frame information from said received signal if said received signal identifies said associated system, said control frame information including the identity of a first possible device control frame; and

deriving a new base frame for said device from said address assigned to said device and from said first possible device control frame.

24. A method for controlling a selective call receiving device as recited in claim 23 wherein said control frame information includes a step value X and said method includes determining a subsequent control frame for said device based on said new base frame plus an integer times 2^X.

25. A method for controlling a selective call receiving device as recited in claim 24 wherein a plurality of control frames are grouped in a cluster for a plurality of selective call receiving devices and said control frame information includes a first distance value representing the distance between control frames within a cluster, said new base frame being derived from said address assigned to said device, said first possible device control frame and said first distance value.

26. A method for controlling a selective call receiving device as recited in claim 25 wherein said control frame information includes a second distance value representing the distance between control frames associated with one device in one cluster and said control frames for said one device are determined based upon said new base frame for said one device plus a first integer times 2^X plus a second integer times said second distance value.