Abstract: An improved network for communication of message packets. The network of the present invention implements an improved collision avoidance, detection and backoff system for communication on a media between nodes. The apparatus calculates a time period P after detecting the media is idle using a formula F which is a function of a pseudo-random delay factor T. If the media remains idle during the time period P, the device may transmit a message. The apparatus further has the ability to assign messages as being either priority or non-priority messages. Priority messages may be transmitted during priority message slots preassigned to transmitting nodes. Non-priority message contend for the media during a period of time following the period set for transmission of priority messages.

Abstract: An improved network for communication of message packets. The present invention provides for improved reliable multicast messaging wherein messages may be reliably multicast to members of a multicast group and acknowledgements may be handled in an improved and efficient manner. In particular, a message may be transmitted to all members of a group, each member of the group responding to receipt of the message with an acknowledgement message. Further, facility is provided to allow for transmissions of reminder messages in the event one or members of a group do not respond to a message with an acknowledgement.

Abstract: A network for sensing, communicating and controlling having a plurality of cells which communicate with packets. A packet requesting acknowledgements is transmitted to a plurality of destination cells. The transmitting cell listens for acknowledgements from the destination cells. The transmitting cell waits a predetermined period of time to receive the acknowledgements and then infers that a collision has occurred if a reply is not received from any of the destination cells. Different actions are taken by the transmitting cells as a result of the inference of collision as opposed to a case where the cell receives an acknowledgement from at least one destination cell.

Abstract: A cell for a network which provides for sensing of conditions, communicating messages and controlling objects through messages encoded into segments of six bit codes each containing 3 binary ones and 3 binary zeros. The messages begin with one predetermined code which provides bit synchronization followed by a second predetermined code which provides byte synchronization.

Abstract: A network for sensing, communcating and controlling including a plurality of cells. Each cell is identified by a permanent, unique identification number. Groups of cells are programmed to perform group functions and are assigned group identification numbers. Communication is performed via a medium using the cell identification numbers and group identification numbers.