Guaranteed reliable broadcast network

• US 5,036,518 A
• Filed: 11/02/1988
• Issued: 07/30/1991
• Est. Priority Date: 11/02/1988
• Status: Expired due to Fees

• Current Assignee: Lawrence C.N. Tseung
• Original Assignee: Lawrence C.N. Tseung
• Inventors: Tseung, Lawrence C. N.
• Primary Examiner(s): Atkinson, Charles E.
• Application Number:
  US07/266,473
• Time in Patent Office: 1,000 Days
• Field of Search: 371/32, 371/33, 340/825.05, 340/825.5, 364/200, 364/222.2, 364/242.95, 370/91, 370/92, 370/94.1, 370/94.3
• US Class Current: 714/748
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 12/1877 Measures taken prior to transmission
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint

Abstract

A system that guarantees reliable data transmission for one-to-many and/or many-to-many communications amongst data processing stations includes several dedicated functions/stations distributed across a communications network. One or more general participant stations connected to a shared communications facility (e.g., a communications network) serves as a source and/or destination of information. A retransmission station receives input data from the general participant stations on a one-to-one basis, generates a special message header, and retransmits the message on the network. A designated recorder station ensures messages sent from the retransmission station are correct. This designated recorder station effectively communicates with the retransmission station on a one-to-one basis over the network, detects missed or corrupted messages, and can request the retransmission station to resend again. The designated recorder station also acknowledges reception of messages from the retransmission station. A playback recorder station listens to and stores the messages from the retransmission station either entirely or selectively. If this station detects missing or corrupted messages, it obtains the correct information from the designated recorder station using one-to-one communications. If a general participant station detects missing or corrupted messages, it obtains the correct information from this playback recorder station using one-to-one communications. A powered off general participant station can regain all the missed messages from the playback recorder station. An optional management station controls orderly start and stop of group communications or conferences and may also handle secure, confidential communications. Examples are provided to show how this guaranteed, reliable, one-to-many or many-to-many system can be applied to overcome previously unsolved problems.

Claims

1. A method of providing guaranteed reliable broadcast data communications to plural digital signal processing stations connected to a digital communications network, said method comprising the steps of:

(a) originating a digital signal message;

(b) assigning a global identifier to said message;

(c) broadcasting said message together with said assigned global identifier over said communications network;

(d) receiving and acknowledging said broadcasted message with a designated recorder station; and

(e) receiving said broadcasted message correctly with substantially 100% reliability at each of said plural stations without requiring acknowledgements from said plural stations.

2. A method as in claim 1 wherein said receiving step (e) includes the steps of:

receiving said broadcasted message with a playback recorder station different from said designated recorder station;

testing for correct receipt of said broadcasted message by said playback recorder station; and

if said testing step reveals said playback recorder station failed to correctly receive said broadcasted message, requesting said designated recorder station to communicate a version of said message over said network to said playback recorder station so as to guarantee said playback recorder station correctly receives said message.

3. A method as in claim 2 wherein said receiving and acknowledging step (d) includes the steps of introducing a time delay before acknowledging said broadcast message with said designated recorder station, and varying said time delay in response to receipt of requests from said playback recorder station to communicate a version of said message over said network to said playback recorder station.

4. A method of ensuring guaranteed reliable data communications between more than two general participant data processing stations all connected to a digital communications network, said method comprising the steps of:

(a) performing a first phase of message communications, said first phase comprising the following steps;

(a1) originating a digital message at a first of said general participant data processing stations,

(a2) transmitting said digital message over said digital communications network, and

(a3) receiving said digital message communicated by said transmitting step (a2) with a retransmission station connected to said network; and

(b) performing a second phase of message communications, said second phase comprising the following steps;

(b1) assigning a global identifier to said message received by said receiving step (a3), and

(b2) broadcasting said message together with said global identifier from said retransmission station over said communications network,

(b3) receiving said broadcasted message by each of said general participant stations correctly with substantially 100% reliability without requiring acknowledgement of said broadcasted message from any of said general participant stations;

wherein said step (b3) includes the additional step of guaranteeing said broadcasted messages are received by a designated recorder station also connected to said network, including the following steps;

(i) receiving said broadcasted messages with said designated recorder station,

(ii) testing for correct reception of said messages by said designated recorder station, and

(iii) generating a positive acknowledge message with said designated recorder station for those messages said testing step reveals said designated recorder station correctly received.

5. A method of providing guaranteed reliable secure digital message exchanges over a digital communications network to plural general participant data processing stations connected to said network, said method comprising the steps of:

(a) generating a data message with a first general participant station;

(b) sending said data message over said digital communications network from said first general participant station to a further station;

(c) encrypting said data message at said further station with a conference encryption key;

(d) broadcasting said encrypted message over said network to said plural general participant stations using a guaranteed reliable one-to-many technique;

(e) providing a subset of said plural general participant stations beforehand with a preassigned conference decryption key corresponding to said conference encryption key; and

(f) independently decrypting said encrypted message only at said general participant stations within said subset using said preassigned conference decryption key.

6. The method of claim 5 wherein said further station is a management station.

7. The method of claim 5 wherein said encrypting step (c) and broadcasting step (d) are performed by the same combined management/retransmission station.

8. The method of claim 5 wherein said broadcasting step (d) includes the following steps:

(i) broadcasting said message with a retransmission station;

(ii) testing for correct receipt of said broadcasted message at each of said plural general participant stations; and

(iii) communicating said message from said retransmission station to those general participant stations, if any;

said testing step (ii) reveals did not correctly receive said broadcasted message.

9. The method of claim 5 wherein said steps (c) and (d) are performed by the same data processing station.

10. The method of claim 5 further including the step of authenticating said first general participant station before performing said encrypting step (c).

11. The method of claim 5 wherein:

said sending step (b) comprises the step of encrypting said message with an individualized encryption key preassigned and corresponding to said first general participant station and communicating said encrypted message to said further station; and

said method further includes the step of decrypting said message at said further station with a decryption key corresponding to said first general participant station individualized encryption key before performing said encrypting step (c).

12. The method of claim 5 wherein:

said sending step (b) includes sending a plurality of fields of said message;

said encrypting step (c) comprises encrypting said plural fields with corresponding plural different encryption keys;

said providing step (e) comprises the step of providing only some of said plural different keys to said authorized general participant stations; and

said decrypting step (f) comprises decrypting some but not all of said plurality of fields encrypted by said encrypting step (c).

13. A method of providing secure one-to-many and many to-many data communications over a digital signal communications network using private and public keys, said network being of the type which permits plural general participant data processing stations to communicate with one another via digital messages, said method comprising the steps of:

(a) encrypting a data message to be broadcasted with a private conference key corresponding to a first general participant station;

(b) broadcasting the enhanced encrypted data message over said communications network to said plural general participant stations connected to said network using a guaranteed reliable one-to-many technique;

(c) pre-authorizing ones of said plural general participant stations beforehand by providing said stations with a public conference key which together with said private conference key forms a private and public key pair; and

(d) decrypting said enhanced encrypted data message at said pre-authorized ones of said plural general participant stations using said public conference key.

14. The method of claim 13 wherein said broadcasting step (b) comprises the following steps:

(i) assigning a global identifier to said encrypted message; and

(ii) broadcasting said message together with said assigned global identifier over said communications network.

15. In a distributed data processing system of the type including a first data processing station connected by a common digital communications network to plural additional stations, said first data processing station being a source of shared data, a method of accommodating sudden changes in demand for computing resources without overloading the first data processing station, said method comprising the following steps:

(a) providing non-shared information in each of said additional data processing stations;

(b) broadcasting shared information as messages from said first data processing station to said additional data processing stations over said communications network using a guaranteed reliable one-to-many technique;

selecting said messages by said additional data processing stations based on the contents of said messages; and

(d) changing the number of said additional data processing stations without significantly affecting the loading of said first data processing station.

16. The method of claim 15 wherein said broadcasting step (b) comprises the following steps:

(i) originating said shared information messages;

(ii) assigning global identifiers to said messages;

(iii) broadcasting said messages together with said assigned global identifiers over said communications network; and

(iv) correctly receiving said messages by each of said additional stations without requiring acknowledgements from said additional stations.

17. A method as in claim 15 wherein said broadcasting step (b) includes the step of correctly receiving each of said messages with each of said plural data processing stations without requiring acknowledgement messages to be generated by said plural stations in response to said broadcasted messages.

18. A method as in claim 17 wherein said correctly receiving step comprises the following steps:

testing for correct receipt of said broadcasted messages at each of said plural stations;

generating request messages only from those of said stations said testing step reveals failed to correctly receive said broadcasted messages; and

retransmitting said incorrectly received messages, if any, over said network from said retransmission station to said stations generating request messages using a known reliable one-to-one communications protocol.

19. A method of providing guaranteed reliable data communications over a digital communications network of the type connected to plural general participant stations to provide demonstrations at each of said plural general participant stations without requiring specialized demonstrator software/hardware to be provided in said plural general participant stations, said method comprising the steps of:

(a) generating a visual display format at a first general participant station;

(b) converting said visual display format at said first general participant station into a display output message representing said display format;

(c) broadcasting said display output message over said network using a guaranteed reliable one-to-many technique;

(d) receiving said broadcasted display output message with each of said general participant stations; and

(e) generating said visual display format independently at each of said plural general participant computers in response to said broadcasted message.

20. A method as in claim 19 further including the steps of:

(f) storing said broadcasted display output message, at a playback recorder station;

(g) communicating said stored message from said playback recorder station to at least one of said plural general participant stations at an arbitrary time subsequent to the time said broadcasting step (c) is performed; and

(h) generating said visual display format at said subsequent time with said one plural general participant computer in response to said communicated message.

21. The method of claim 19 wherein said broadcasting step (c) comprises the following steps:

(i) assigning a global identifier to said message;

(ii) broadcasting said message together with said assigned global identifier over said communications network;

(iii) receiving and storing said broadcasted message; and

(iv) correctly receiving said messages with substantially 100% reliability by each of said plural stations without requiring acknowledgements from said plural stations.

22. The method of claim 19 further including the step of editing the visual/display format generated by at least one of said general participant stations in response to said broadcasted message to include additional features and/or exclude unwanted features.

23. The method of claim 19 further including the step of simultaneously displaying said visual display format and providing audio information at each of said plural general participant stations in response to receipt of said broadcasted message.

24. A method of providing guaranteed reliable broadcast data communications over a digital communications network for an unknown number of plural general participant stations connected to said network, said system comprising the steps of:

(a) selecting a conference number;

(b) generating data to be processed by a subset of said plural general participant stations associated with said conference number;

(c) incorporating said conference number and said generated data into a message;

(d) broadcasting said message over said network using a guaranteed reliable one-to-many technique;

(e) receiving said broadcasted message with said plural general participant stations; and

(f) processing said received generated data at said plural stations within said subset in response to said received conference number.

25. The method of claim 24 wherein said broadcasting step (d) comprises the following steps:

(i) assigning a global identifier to said message;

(ii) broadcasting said message together with said assigned global identifier over said communications network;

(iii) receiving and storing said broadcasted message; and

(iv) correctly receiving said messages by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

26. A method as in claim 24 further including the following steps:

(g) repeating said steps (b)-(f) a plurality of times;

(h) associating a further station with said conference number subsequent to at least one repetition of said steps (d) and (e) such that said further station does not receive at least one of said messages broadcasted by said step (d);

(i) performing said receiving step (e) with said further station for each message broadcasted by said broadcasting step (d) subsequent to the time said associating step (h) is performed; and

(j) providing said further station with all messages broadcasted by said broadcasting step (d) prior to the time said associating step (h) is performed.

27. A method as in claim 26 wherein said providing step (j) includes the following steps:

(j1) receiving each of said broadcasted messages with a playback recorder station connected to said network;

(j2) storing said messages received by said receiving step (j1); and

(j3) communicating stored versions of all messages broadcasted by said broadcasting step (d) prior to the time said associating step (h) is performed over said network from said playback recorder station to said further station.

28. A method of distributing software to plural data processing stations of the type including a base sequence of program control instructions for controlling the operations thereof, said plural stations being connected to a digital communications network, said method comprising the steps of:

(a) providing an update sequence of program control instructions to be distributed;

(b) providing a further sequence of program control instructions;

(c) dividing said update program control instruction sequence into packets having lengths suitable for network transmission;

(d) broadcasting said packets over said network using a guaranteed reliable one-to-many technique;

(e) broadcasting said further program control instruction sequence over said network using said guaranteed reliable one-to-many technique;

(f) receiving said broadcasted packets and said broadcasted further program control instruction sequence at each of said plural data processing stations; and

(g) executing said received further program control instruction sequence at each of said plural stations, including the step of automatically controlling the application of said update program control sequence to said base program control sequence at each of said plural stations under control of said received further program control instruction sequence in response to said received packets.

29. The method of claim 28 wherein said broadcasting steps (d) and (e) each comprise the following steps:

(i) formatting said program control instruction sequence into at least one message;

(ii) assigning a global identifier to said message;

(iii) broadcasting said message together with said corresponding assigned global identifier over said communications network; and

(iv) correctly receiving said message by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

30. A method of monitoring activities on a digital communications network of the type connected to plural general participant data processing stations, said method comprising the steps of:

(a) applying inputs to a first general participant station;

(b) generating messages at said first general participant station, said generated messages specifying all of said inputs applied by said applying step (a);

(c) broadcasting said generated messages over said digital communications network using a guaranteed reliable one-to-many technique; and

(d) receiving and storing said broadcasted messages with a further playback recorder data processing station connected to said network.

31. The method of claim 30 wherein:

said steps (a)-(c) are performed for each of said plural general participant stations; and

said step (d) comprises the step of receiving said storing said broadcasted messages generated by all of said plural general participant stations.

32. The method of claim 30 wherein said broadcasting step (c) comprises the following steps:

(i) assigning global identifiers to said messages;

(ii) broadcasting said messages together with said corresponding assigned global identifiers over said communications network; and

(iii) correctly receiving said broadcasted messages by said playback recorder station with substantially 100% reliability without requiring acknowledgements from said playback recorder station.

33. In a digital communications network of the type connecting plural data processing stations, a method of providing conferencing for said plural data processing stations, said method comprising the steps of:

(a) selecting a first conference number designating a first subset of said plural stations;

(b) selecting a further conference number different from said first conference number designating a further subset of said plural stations, at least one of said stations being within both said first and further subsets;

(c) broadcasting a first message over said communications network to said plural data processing stations using a guaranteed reliable one-to-many technique, said first message specifying said first conference number;

(d) broadcasting a further message over said communications network to said plural data processing stations using said guaranteed reliable one-to-many technique, said further message specifying said further conference number;

(e) receiving and processing said first broadcasted message with each of said plural data processing stations within said first subset in response to said received first conference number; and

(f) receiving and processing said further broadcasted message with each of said plural data processing stations within said further subset in response to said received further conference number.

34. The method of claim 33 wherein said broadcasting steps (c) and (d) each comprise the following steps:

(i) assigning a global identifier to said message;

(ii) broadcasting said message together with said assigned global identifier over said communications network; and

(iii) correctly receiving said message by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

35. A method as in claim 33 further including the following steps:

(i) repeating said step (c) a plurality of times;

(ii) associating a further station with said first conference number subsequent to at least one repetition of said step (c) such that said further station does not receive at least one of said messages broadcasted by said step (c);

(iii) performing said receiving step (e) with said further station for each message broadcasted by said broadcasting step (c) subsequent to the time said associating step (ii) is performed; and

(iv) providing said further station with all messages broadcasted by said broadcasting step (c) prior to the time said associating step (ii) is performed.

36. A method as in claim 35 wherein said providing step (iv) includes the following steps:

(j1) receiving each of said broadcasted messages with a playback recorder station connected to said network;

(j2) storing said messages received by said receiving step (j1); and

(j3) communicating stored versions of all messages broadcasted by said broadcasting step (c) prior to the time said associating step (ii) is performed over said network from said playback recorder station to said further station

37. A method of managing the broadcast capability of a communications network of the type connected to plural data processing stations, said method comprising the steps of:

(a) communicating messages from a first of said plural stations to a management station over said communications network;

(b) authorizing said communicated messages for broadcast at said management station; and

(c) broadcasting the authorized messages over said communications network to said plural stations using a guaranteed reliable one-to-many technique.

38. The method of claim 37 wherein said broadcasting step (c) comprises the following steps:

(i) assigning global identifiers to said messages;

(ii) broadcasting said messages together with said assigned global identifiers over said communications network; and

(iii) correctly receiving said messages by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

39. In a digital communications system of the type including a communications network connecting plural data processing stations each having an operating state, a method of providing a backup of a first of said data processing stations, said method comprising the steps of:

(a) making a non-volatile copy of said first data processing station initial operating state;

(b) applying inputs to said first data processing station;

(c) changing said first data processing station operating state in response to said applied inputs;

(d) generating messages indicating said applied inputs;

(e) broadcasting said messages over said communications network using a guaranteed reliable one-to-many technique;

(f) receiving and storing said broadcasted messages with a playback recorder data processing station connected to said network; and

(g) recovering from failure of said first data processing station, including the following steps;

(g1) initializing a further one of said data processing stations similar to said first data processing station with said initial operating state copy,

(g2) communicating versions of said stored broadcasted messages from said playback recorder station over said network to said further data processing station,

(g3) processing said inputs indicated by said supplied message versions with said further station in the same order said inputs were applied to said first station by said applying step (b), and

(g4) changing the operating state of said further station from said initial operating state to the operating state of said first station at the time of failure of said first station in response to said processing step.

40. The method of claim 39 wherein said broadcasting step (e) comprises the following steps:

(i) assigning global identifiers to said messages;

(ii) broadcasting said messages together with said assigned global identifiers over said communications network; and

(iii) correctly receiving said messages by said playback recorder station and at least one other of said stations without with substantially 100% reliability requiring acknowledgements from said at least one other station.

41. The method of claim 39 wherein:

said changing step (g4) includes producing outputs in response to said input message versions; and

said method further comprises the steps of;

(i) generating first state change messages indicating said operating state changes effected by said changing step (c);

(ii) generating outputs at said first station in response to said applied inputs and/or said changes;

(iii) generating output messages indicating said generated outputs;

(iv) repeating said steps (e) and (f) for said state change messages and for said output messages; and

(v) ensuring said operating state of said further station does not drift with respect to the first station operating state at the time of said first station failed, including the steps of;

supplying versions of said state change messages and said output messages from said playback recorder station to said further station over said network.

comparing said operating state changes made by said processing step with said state changes indicated by said operating state change message versions, and

comparing said outputs produced by said processing step with said outputs indicated by said output message versions

42. In a digital communications system of the type including a communications network connecting plural data processing stations each having an operating state, a method of providing at least one hot standby station comprising the steps of:

(a) copying of said primary data processing station initial operating state onto a secondary data processing station;

(b) applying inputs to said first data processing station;

(c) changing said first data processing station operating state in response to said applied inputs;

(d) generating messages indicating said applied inputs;

(e) broadcasting said messages over said communications network using a guaranteed reliable one-to-many technique;

(f) receiving said broadcasted messages with said secondary data processing station;

(g) processing said inputs indicated by said supplied messages with said secondary station in substantially the same order said inputs were applied to said first station by said applying step (b), and

(h) changing the operating state of said further station from said initial operating state to the operating state of said first station in response to said input processing performed by said step (g).

43. The method of claim 42 wherein said broadcasting step (e) comprises the following steps:

(i) assigning global identifiers to said messages;

(ii) broadcasting said messages together with said assigned global identifiers over said communications network; and

(iii) correctly receiving said messages by said secondary station with substantially 100% reliability without requiring acknowledgements from said secondary station.

44. A method as in claim 42 wherein said (a) and (f)-(h) are performed by an arbitrary number of plural secondary stations connected to said network.

45. The method of claim 42 wherein

said changing step (h) includes producing outputs in response to said input message versions;

and

said method further comprises the steps of;

(i) generating first state change messages indicating said operating state changes effected by said changing step (c);

(ii) generating outputs at said first station in response to said applied inputs and/or said changes;

(iii) generating output messages indicating said generated outputs;

(iv) repeating said steps (e) and (f) for said state change messages and for said output messages; and

(v) ensuring said operating state of said further station does not drift with respect to the first station operating state, including the steps of;

comparing said operating state changes made by said processing step with said state changes indicated by said operating state change message versions, and

comparing said outputs produced by said processing step with said outputs indicated by said output message versions

46. In a distributed processing system of the type including plural data processing stations connected to a common digital communications network, said plural stations each including a means for a processing task different from processing tasks performed by others of said plural stations, a method of efficiently performing on-line transaction processing comprising the steps of:

(a) performing data processing tasks in a distributed manner with said plural data processing stations;

(b) generating a processing request for a first processing task with a general participant data processing station connected to said network;

(c) broadcasting said processing request over said network using a guaranteed reliable one-to-many technique;

(d) receiving said broadcasted processing request message with each of said plural data processing stations;

(e) performing said processing task in response to receipt of said broadcasted message by one of said plural stations preprogrammed to perform said first task; and

(f) communicating a result, if any, of said first processing task performing step over said network to said general participant station.

47. The method of claim 46 wherein said broadcasting step (c) comprises the following steps:

(i) assigning a global identifier to said processing request message;

(ii) broadcasting said message together with said assigned global identifier over said communications network; and

(iii) correctly receiving said messages by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

48. In a distributed data processing system of the type including a communications network connecting plural data processing stations, a method of managing a distributed database comprising the steps of:

(a) storing portions of a unitary database in a distributed manner at said plural data processing stations;

(b) generating plural database change requests, affecting certain of said database portions;

(c) communicating said plural change requests to a retransmission station connected to said network;

(d) serializing said communicated change requests into a sequence;

(e) broadcasting said serialized change requests over said network using a guaranteed reliable one-to-many technique; and

(f) effecting changes to said database portions in the order of said sequence in response to receipt of said broadcasted change requests by the ones of said stations storing said certain database portions, including the following steps;

(f1) testing for conflicts between broadcasted change requests affecting the same database portion, and

(f2) failing to process a change request later in said sequence if said testing step reveals said later change request conflicts with a change request earlier in said sequence.

49. The method of claim 48 wherein said broadcasting step (e) comprises the following steps:

(i) assigning global identifiers to said change requests;

(ii) broadcasting said change requests together with said assigned global identifiers over said communications network; and

(iii) correctly receiving said messages by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

50. In a data processing system of the type including a digital communications network connecting plural data processing stations, a method of distributing database processing comprising the steps of:

(a) generating a plural message containing different types of information;

(b) broadcasting said message over said communications network using a guaranteed reliable one-to-many technique;

(c) receiving said broadcasted first and second message with each of said plural data processing stations; and

(d) selectively accepting said received message with each of said data processing stations in response to said information types said message contains.

51. The method of claim 50 wherein said broadcasting step (b) comprises the following steps:

(i) assigning global identifiers to said messages;

(ii) broadcasting said message together with said assigned global identifier over said communications network; and

(iii) correctly receiving said messages by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

52. A method as in claim 50 wherein:

said method further includes the following steps;

(i) encrypting a first subset of fields within said message with a first encryption key prior to said broadcasting step (b);

(ii) encrypting a second subset of fields within said message with a second encryption key prior to said broadcasting step (b);

(iii) providing a first subset of said stations with a first decryption key corresponding to said first encryption key;

(iv) providing a second subset of said stations with a second decryption key corresponding to said second encryption key;

(v) decrypting said first subset of fields by said first subset of stations with said first decryption key; and

(vi) decrypting said second subset of fields by said second subset of stations with said second decryption key.

53. In a distributed process control system of the type including plural data processing stations connected to a common digital communications network, said plural stations being preprogrammed to perform different processing tasks, a method of eliminating the need for a powerful master data processing station comprising the steps of:

(a) originating processing command messages;

(b) broadcasting said messages over said network using a guaranteed reliable one-to-many technique; and

(c) performing said processing tasks at said plural stations in a distributed manner in response to receipt of said broadcasted messages.

54. The method of claim 53 wherein said broadcasting step (b) includes the following steps:

(i) assigning global identifiers to said messages;

(ii) broadcasting said messages together with said assigned global identifiers over said communications network; and

(iii) correctly receiving said messages by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

55. In a distributed processing system of the type including plural data processing stations connected to a common digital communications network, said plural stations each including means for storing a portion of a unitary database, a method of efficiently processing database requests comprising the steps of:

(a) storing said database in a distributed manner with said plural data processing stations;

(b) generating a database request with a general participant data processing station connected to said network;

(c) broadcasting said database request over said network using a guaranteed reliable one-to-many technique;

(d) receiving said broadcasted database request with each of said plural data processing stations;

(e) accessing said database portion stored by a first of said plural data processing stations in response to said broadcasted database request to provide a result; and

(f) communicating said result of said accessing step (e) over said network to said general participant station.

56. The method of claim 55 wherein said broadcasting step (c) comprises the following steps:

(i) assigning a global identifier to said processing request message;

(ii) broadcasting said message together with said assigned global identifier over said communications network; and

(iii) correctly receiving said messages by each of said plural stations with substantially 100% reliability without requiring acknowledgements from said plural stations.

57. A method as in claim 55 wherein:

first and second ones of said plural data processing stations each store the same portion of said database;

said receiving step (d) includes the steps of receiving said broadcasted message with each of said first and second stations;

said method further includes the following steps;

(i) applying a first volunteer message to said communications network with said first station in response to receipt by said first station of said broadcasted message,

(ii) applying a second volunteer message to said network with said second station in response to receipt by said second station of said broadcasted message, and

(iii) selecting one of said first and second stations in response to said first and second volunteer messages; and

said accessing step (e) and communicating step (f) are performed only by said station selected by said selecting step (iii).

58. A method as in claim 55 wherein said storing step comprises the steps of:

storing a first portion of said unitary database at a first of said plural stations, and

storing a second database portion logically related to said first portion at a second of said plural stations;

said accessing step comprises the step of concurrently accessing said first and second related portions independently at said first and second plural stations, respectively, in response to receipt by said first and second stations of said broadcasted database request; and

said communicating step comprises the step of communicating a result of said accessing step from each of said first and second stations to said general participant station.

59. A system for providing guaranteed reliable broadcast data communications to plural digital signal processing stations connected to a digital communications network, said system comprising:

message originating means connected to said network for originating a digital signal message;

assigning means for assigning a global identifier to said message;

broadcasting means, connected to said network and also connected to receive said originated message and said assigned global identifier, for broadcasting said message together with said assigned global identifier over said communications network;

designated recorder means connected to said network for receiving and acknowledging said broadcasted messages;

receiving means within each of said plural stations connected to said network for receiving said broadcasted message at each of said plural stations; and

guaranteeing means connected to said network for guaranteeing correct reception of said message by each of said plural station receiving means without requiring acknowledgements from said plural stations.

60. A system as in claim 59 wherein said designated recorder means includes means for introducing a time delay before acknowledging said broadcasted message and for varying said time delay in response to receipt of requests for said playback recorder means.

61. A system as in claim 59 wherein said guaranteeing means includes:

a playback recorder station connected to said network for receiving said broadcasted message;

means connected to at least one of said station receiving means for testing for correct receipt of said broadcasted message by said station receiving means; and

providing means, connected to said playback recorder station and communicating with said testing means, for providing said message received by said playback recorder station over said network to said station receiving means if said testing means reveals said station receiving means failed to correctly receive said broadcasted message so as to guarantee correct reception of said message by said station receiving means.

62. A system as in claim 59 wherein:

said system further includes;

transmitting means connected to said originating means and to said network for transmitting said message over said network and;

retransmission receiving means connected to said network and to said broadcasting means for receiving said transmitted message and for controlling said broadcasting means to broadcast said message;

wherein said designated recorder means also connected to said communications network for receiving said broadcasted message and for testing for correct receipt of said broadcasted message, said designated recorder means including means for communicating an acknowledgement message to said retransmission receiving means over said communications network if said testing means reveals said designated recorder means correctly received said broadcasted message;

said retransmission receiving means also for receiving said acknowledgement message; and

control means connected to said retransmission receiving means and to said broadcasting means for controlling said broadcasting means to repeat broadcast of said message in response to failure of said retransmission receiving means to receive said acknowledgement message from said designated recorder station; and

wherein each of said plural stations includes means for inhibiting generation of an acknowledgement message in response to correct receipt of said broadcasted message.

63. A system for providing guaranteed reliable broadcast data communications comprising:

a digital communications network;

plural digital signal processing stations connected to said digital communications network;

means connected to said communications network for applying messages to said communications network;

a retransmission station connected to said network, said retransmission station including;

receiving means for receiving said applied messages,

serializing means connected to said receiving means for serializing said received messages into a sequence, including means for assigning a different identifier to each of said received messages, said assigned identifiers indicating the order for said messages in said sequence, and

broadcasting means connected to said serializing means for broadcasting each of said messages together with said identifier corresponding thereto over said communications network to said plural stations;

means connected to said network for guaranteeing reception of said messages by each of said plural stations; and

processing means operatively associated with each of said plural stations for processing said received messages in the order of said sequence in response to said identifiers associated with said received messages, wherein said guaranteeing means includes;

a designated recorder station comprising;

receiving means connected to said network for receiving said broadcasted messages,

testing means connected to said designated recorder station receiving means for testing for correct reception for said messages by said designated recorder station receiving means, and

acknowledgement message generating means connected to said network and to said testing means for generating a positive acknowledgement message for those messages said testing means reveals said designated recorder station receiving means correctly received.

64. A system for ensuring guaranteed reliable broadcast data communications comprising:

a digital communications network;

plural general participant stations connected to said network;

message originating means within at least one of said general participant stations for originating a message;

broadcasting means connected to said network and connected to receive said originated message for broadcasting said message over said communications network to said plural general participant stations using a guaranteed reliable one-to-many technique; and

playback recorder means connected to said network for receiving and broadcasted message and for storing said received message, said playback recorder means including recovering means for later recovering from the failure of one of said general participant stations to receive said broadcasted message, said recovering means including communicating means for communicating said storing message to said one general participant station over said communications network, said broadcasting means including a designated recorder station connected to said network, said designated recorder station including;

receiving means for receiving said broadcasted message, and

means connected to said receiving means for temporarily storing said received message;

said playback recorder means including testing means for testing for correct receipt of said broadcasted message; and

said designated recorder means further includes communicating means in communication with said testing means for communicating said temporarily stored message over said network from said designated recorder station to said playback recorder means if said testing means reveals said playback recorder means failed to correctly receive said broadcasted message.