Protocol for network having a plurality of intelligent cells

• US 4,947,484 A
• Filed: 11/08/1988
• Issued: 08/07/1990
• Est. Priority Date: 11/10/1987
• Status: Expired due to Term

• Current Assignee: Echelon Systems Corp.
• Original Assignee: Echelon Systems Corp.
• Inventors: Sander, Wendell B., Twitty, William B.
• Primary Examiner(s): Atkinson, Charles E.
• Application Number:
  US07/268,933
• Time in Patent Office: 637 Days
• Field of Search: 371/37, 371/32, 371/33, 371/52, 371/37.1, 370/85, 370/86, 370/94
• US Class Current: 714/776
• CPC Class Codes: G08C 15/00 Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path
• CPC Class Codes: H02J 13/00007 using the power network as support for the transmission
• CPC Class Codes: H02J 13/00028 involving the use of Internet protocols
• CPC Class Codes: H05B 47/155 Coordinated control of two or more light sources
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/246 the system involving the remote operation of lamps or lighting equipment

Abstract

A network for sensing, communicating and controlling, which uses packets to communicate between a plurality of cells. Cells in a system are given a system identification number (e.g., a 48 bit number). One part of the system identification number (e.g., 32 bits) is transmitted with a packet. The remaining part of this system identification number (e.g., 16 bits) is included in the computation of a cyclic redundancy code (CRC). A receiving cell is able to verify that a packet is intended for it by examining the first part of the system identification number in the packet and by computing and comparing the CRC in the same manner as was done by the transmitting cell.

Claims

1. In a network for sensing, communicating and controlling, where packets are communicated between a plurality of cells, an improved method for including in said packets representations of a system identification number of N bits comprising the steps of:

including a portion of said N bit identification number in a field within each of said packets;

using the remaining bits of said N bit identification number in the calculation of a cyclic redundancy code (CRC), said CRC calculation including other fields in said packet;

transmitting the results of said CRC calculation with said packet.

2. The method defined by claim 1 including the additional steps of:

receiving said packet;

calculating the CRC for said other fields of said packet using said system identification number in said calculation;

comparing the results of said calculation with said results of said CRC calculation transmitted with said packet.

3. The method defined by claim 1 wherein the portion of said CRC calculation using said remaining bits of said N bit identification number is stored for use in subsequent CRC calculations.

4. The method defined by claims 1 or 2 including the additional step of converting said predetermined fields of said packet into segments of six bit codes where each segment comprises three binary ones and three binary zeroes.

5. In a network for sensing, communicating and controlling, where a plurality of cells communicate with one another with packets, each of said packets comprising a plurality of first fields, an improvement comprising the steps of:

including with said packet a second field the value of which represents the total time waited by all of said cells to transmit one of said packets;

including with said packet a first verification number calculated for said first fields, said first number being used to verify the accuracy of transmission of said first fields;

including with said packet a second verification number calculated for said second field, said second verification number being used to verify the accuracy of transmission of said second field;

whereby said first verification number may be calculated before said second field is determined.

6. The method defined by claim 5 wherein said first verification number is a cyclic redundancy code.

7. The method defined by claim 6 wherein said second verification number is a cyclic redundancy code.

8. In a network having a plurality of cells which communicate with one another with packets, where each of said cells includes processing means for preparing and interpreting said packets, some of said cells for repeating said packets, an improvement comprising:

a field in said packets representing the time one or more of said repeater cells waits to transmit a packet;

said processing means of each of said repeater cells including means for counting the time said cell waits for transmitting a packet and means for operating upon said field to indicate in said field said time said cell waits,

whereby an improved network is realized.

9. The improvement defined by claim 8 wherein, when said field reaches a predetermined number, said cell discards said packet rather than transmitting it.

10. The method defined by claim 9 wherein said processing means calculates a cyclic redundancy code for said field.