Terminal polling method

• US 5,053,883 A
• Filed: 04/20/1989
• Issued: 10/01/1991
• Est. Priority Date: 12/23/1988
• Status: Expired due to Term

• Current Assignee: Tech 5 SAS
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Johnson, Lee R.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/340,659
• Time in Patent Office: 894 Days
• Field of Search: 364/241.1 MS File, 380/3, 380/4, 380/10, 358/349, 358/84, 358/86, 455/2, 340/825.08, 340/825.52, 370/85.8, 370/95.2
• US Class Current: 725/114
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04N 21/2143 located in a single building, e.g. hotel, hospital or museum arrangements specially adapted for plural spots in a confined site in broadcast systems H04H20/63; adaptations for transmission by electric cable for domestic distribution in television systems H04N7/106
• CPC Class Codes: H04N 21/47 End-user applications
• CPC Class Codes: H04N 21/478 Supplemental services, e.g. displaying phone caller identification, shopping application
• CPC Class Codes: H04N 21/6402 Address allocation for clients address allocation in data networks H04L61/50
• CPC Class Codes: H04N 7/0888 Subscription systems therefor
• CPC Class Codes: H04N 7/165 Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/173 with two-way working, e.g. subscriber sending a programme selection signal
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

A method of transferring data from a plurality of remote terminals to a central location over a communication network is disclosed. First random numbers are respectively generated for each of the remote terminals. A mask value is then determined. The random numbers associated with the remote terminals are compared with the mask value to determine whether a respective terminal attempts to transfer data to the central location. In a disclosed embodiment the method is used to locate new terminals in a hotel or hospital system.

Claims

1. A method of controlling the transfer of data from a plurality of remote terminals to a central location over a communication network, said method comprising the steps of:

generating random numbers respectively associated with each of said plurality of remote terminals;

determining a mask value at the central location;

prompting said remote terminals by said central location; and

comparing the random numbers associated with each remote terminal with said mask value to determine whether a respective terminal should transfer data to said central location based on the result of the comparison when said remote terminals are prompted by said central location.

2. The method according to claim 1 further comprising the step of:

incrementing the random number associated with each remote terminal by a predetermined value if data is not transferred to said central location when said remote terminals are prompted by said central location.

3. The method according to claim 2 further comprising the steps of:

monitoring the number of times the remote terminals are prompted to transfer data to said central location;

generating new random numbers associated with each remote terminal when the monitored number of times has a predetermined relationship with said mask value.

4. The method according to claim 3 wherein new random numbers associated with each remote terminal are generated when the monitored number of times equals the mask value.

5. The method according to claim 2 wherein the random number is increased by a predetermined value.

6. The method according to claim 5 wherein the predetermined value is one.

7. The method according to claim 2 wherein the random number is decreased by a predetermined value.

8. The method according to claim 7 wherein the predetermined value is one.

9. The method according to claim 1 wherein the random numbers associated with each remote terminal are generated by a counter associated with each terminal.

10. The method according to claim 1 wherein the mask value is determined in accordance with the number of remote terminals.

11. The method according to claim 1 wherein the comparing step comprises logically comparing the random numbers with the mask value.

12. The method according to claim 11 wherein the random numbers are ANDed with the mask value.

13. The method according to claim 1 wherein said communication network comprises a telephone network.

14. A method of automatically identifying a plurality of remote terminals each having a unique identifier from a central location, said method comprising the steps of:

generating random numbers respectively associated with each of said plurality of remote terminals;

determining a mask value at the central location;

transmitting commands to said remote terminals by said central location; and

comparing the random numbers associated with each remote terminal with said mask value to determine whether a respective terminal should transfer the identifier to said central location in response to the commands transmitted by said central location.

15. The method according to claim 14 wherein the central location has a list of stored identifiers, the method further comprising the step of:

comparing an identifier transferred to said central location with the list of stored identifiers to determine whether the transferred identifier is contained in the list of stored identifiers.

16. The method according to claim 15 wherein if the transferred identifier is contained in the list of stored identifiers, the method further comprising the steps of:

conditioning the remote terminal associated with the transferred identifier to not attempt to transfer the associated unique identifier to said central location in response to commands transmitted by said central location.

17. The method according to claim 15 wherein if the transferred identifier is not contained in the list of stored identifiers, the method further comprising the steps of:

adding the transferred identifier to the list of stored identifiers;

conditioning the remote terminal associated with the transferred identifier to not attempt to transfer the associated unique identifier to said central location in response to commands transmitted by said central location.

18. An apparatus for controlling the transfer of data to a central location over a communication network, the central location determining a mask value and transmitting commands, said apparatus comprising:

random number generating means for generating a random number;

comparison means for comparing the random number with the mask value determined by said central location to determine whether the apparatus should transfer data to said central location in response to the commands transmitted by said central location based on the result of the comparison.

19. The apparatus according to claim 18 wherein said apparatus is adapted to transfer data over a telephone network.

20. The apparatus according to claim 18 wherein said random number generating means comprises a counter.

21. The apparatus according to claim 18 wherein said comparison means comprises an arrangement of logic gates.

22. The apparatus according to claim 21 wherein said logic gates comprise AND gates.

23. Control apparatus for controlling the transfer of stored data to a central location from a plurality of remote terminals over a communication network, each terminal having a random number generator, said control apparatus comprising:

prompt means at the central location for prompting each of the remote terminals to generate a respective random number;

mask means at the central location for determining a mask value;

compare means for comparing the random numbers respectively generated in the remote terminals with the mask value to determine whether a respective terminal should transfer data to said central location based on the result of the comparison.

24. A method of controlling the transfer of data from a plurality of remote terminals to a central location over a communication network, said method comprising the steps of:

generating random numbers respectively associated with each of said plurality of remote terminals;

determining a mask value;

prompting said remote terminals by said central location;

comparing the random numbers associated with each remote terminal with said mask value to determine whether a respective terminal should transfer data to said central location based on the result of the comparison when said remote terminals are prompted by said central location;

incrementing the random number associated with each remote terminal by a predetermined value if data is not transferred to said central location when said remote terminals are prompted by said central location;

monitoring the number of times the remote terminals are prompted to transfer data to said central location; and

generating new random numbers associated with each remote terminal when the monitored number of times has a predetermined relationship with said mask value.

25. The method according to claim 24 wherein new random numbers associated with each remote terminal are generated when the monitored number of times equals the mask value.

26. A method of automatically identifying a plurality of remote terminals each having a unique identifier from a central location, the central location having a list of stored identifiers, said method comprising the steps of:

generating random numbers respectively associated with each of said plurality of remote terminals;

determining a mask value;

transmitting commands to said remote terminals by said central location;

comparing the random numbers associated with each remote terminal with said mask value to determine whether a respective terminal should transfer the identifier to said central location in response to the commands transmitted by said central location; and

comparing an identifier transferred to said central location with the list of stored identifiers to determine whether the transferred identifier is contained in the list of stored identifiers.

27. The method according to claim 26 wherein if the transferred identifier is contained in the list of stored identifiers, the method further comprising the steps of:

conditioning the remote terminal associated with the transferred identifier to not attempt to transfer the associated unique identifier to said central location in response to commands transmitted by said central location.

28. The method according to claim 27 wherein if the transferred identifier is not contained in the list of stored identifiers, the method further comprising the steps of:

adding the transferred identifier to the list of stored identifiers;

conditioning the remote terminal associated with the transferred identifier to not attempt to transfer the associated unique identifier to said central location in response to commands transmitted by said central location.

29. A method of controlling a plurality of remote terminals which transmit data to a central location over a communication network in response to commands from said central location, said method comprising the steps of:

generating random numbers in said remote terminals in response to a first command;

setting a predetermined number in said remote terminals to fix a frequency at which said remote terminals respond to a second command;

comparing the random numbers in said remote terminals with the predetermined number; and

transmitting data from said remote terminals over said communication network in accordance with the comparisons of the random numbers with the predetermined number.

30. The method according to claim 29 wherein said communication network comprises an RF data channel.

31. The method according to claim 29 wherein said method further comprises the step of:

transmitting an acknowledgment from said central location to remote terminals transmitting data which is received by said central location.

32. The method according to claim 31 further comprising the step of:

incrementing the random numbers in unacknowledged remote terminals to generate new random numbers in said unacknowledged remote terminals;

comparing the new random numbers in said unacknowledged remote terminals with the predetermined number; and

transmitting the data from said unacknowledged remote terminals over said communication network in accordance with the comparisons of the new random numbers with the predetermined number.

33. The method according to claim 32 wherein the steps of claim 32 are repeated until said central location transmits an acknowledgment to each of said remote terminals.

34. The method according to claim 29 wherein the step of generating random numbers comprises reading a counter respectively associated with each of said remote terminals.

35. The method according to claim 29 wherein the step of setting the predetermined number comprises transmitting the predetermined number from said central location to said remote terminals.