Asynchronous data transmission

• US 20080137662A1
• Filed: 10/05/2007
• Published: 06/12/2008
• Est. Priority Date: 10/05/2006
• Status: Active Grant

• Current Assignee: John M. Holt
• Original Assignee: John M. Holt
• Inventors: Holt, John M.
• Granted Patent: US 7,852,845 B2
• Time in Patent Office: Days
• US Class Current: 370/394
• CPC Class Codes: G06F 9/54 Interprogram communication
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A method of, and system for, asynchronous data transmission are disclosed which have application in the transmission of stock exchange data or replicated memory data. Later transmitted data (14) is used to overwrite earlier transmitted and received data (13). However, earlier transmitted data (14) which is received later than later transmitted data (15) (for example due to network latency) does not overwrite the later transmitted data (15). Transmitted data packets include a count value (15) indicative of the sequence position of each data packet in a transmitted sequence (13, 14, 15) of data packets. A transmitter and receiver for asynchronous data transmission and reception, and a packet signal structure are also disclosed.

Claims

1. A transmitter for transmitting an updating data packet to an external receiver, said transmitter characterized in that:

said transmitter is adapted to transmit said updating data packet that forms part of a sequence of information and each updating data packet transmitted being intended to overwrite a previously transmitted data packet, each said updating data packet transmitted comprises (i) an identifier of the replicated memory location to be updated, (ii) the content with which said replicated memory location is to be updated, and (iii) a resident updating count of the updating source associated with the identified replicated memory location, and each updating data packet comprising (a) a updating data identifier, (b) a updating data content, and (c) an updating count value; and

said transmitter including a count valuer within said transmitter for determining a magnitude of the updating count value for each data packet transmitted, said updating count value indicating the position of said updating data packet in said sequence of information.

2. A transmitter as in claim 1, further including the external receiver.

3. A method for transmitting an updating data packet to an external receiver, said method for transmitting comprising:

transmitting said updating data packet to an external receiver;

said transmitted updating data packet forms part of a sequence of transmitted information and each updating data packet transmitted is transmitted with the intention to overwrite a previously transmitted data packet, each said updating data packet transmitted comprises (i) an identifier of the replicated memory location to be updated, (ii) the content with which said replicated memory location is to be updated, and (iii) a resident updating count of the updating source associated with the identified replicated memory location, and each updating data packet comprising (a) a updating data identifier, (b) a updating data content, and (c) an updating count value; and

determining a magnitude of the updating count value for each data packet transmitted, said updating count value indicating the position of said updating data packet in said sequence of information.

4. A computer program stored in a computer readable media, the computer program adapted for execution in a processor within a computer or information appliance and a memory coupled with the processor to modify the operation of the computer or information appliance, for modifying the operation of the computer or information appliance, the modification including performing a method transmitting an updating data packet to an external receiver, said method comprising:

transmitting said updating data packet to an external receiver;

said transmitted updating data packet forms part of a sequence of transmitted information and each updating data packet transmitted is transmitted with the intention to overwrite a previously transmitted data packet, each said updating data packet transmitted comprises (i) an identifier of the replicated memory location to be updated, (ii) the content with which said replicated memory location is to be updated, and (iii) a resident updating count of the updating source associated with the identified replicated memory location, and each updating data packet comprising (a) a updating data identifier, (b) a updating data content, and (c) an updating count value; and

determining a magnitude of the updating count value for each data packet transmitted, said updating count value indicating the position of said updating data packet in said sequence of information.

5. A receiver for asynchronous receiving of updating data packets by a single computer operating within a multiple computer system, the receiver adapted for receiving a transmission from an external transmitter, the receiver comprising:

a count comparator for comparing a currently received updating count value received from said external transmitter with a previously received updating count value; and

data content writing means for overwriting the previously received data content with the currently received data content only if the current received updating count is greater than the previously received updating count.

6. A receiver system as in claim 5, further including the external transmitter.

7. A transceiver system including a transmitter and a at least one receiver for asynchronous transmission and reception of data packets;

said transmitter operative to transmit said data packets each forming part of a sequence of information and each intended to overwrite a previously transmitted packet of information in said receiver, and each packet comprising a data identifier, a data content and a packet count value, said system comprising a count valuer within a transmitter to determine the magnitude of the packet count value for each data packet, said count value indicating the position of said data packet in said sequence;

the or said receiver including a count comparison means to compare the currently received packet count value with the previously received packet count value and overwriting the previously received data content with the currently received data content only if the current received packet count exceeds the previously received packet count.