Method and system for transmitting periodic and aperiodic data over a critical avionics databus

A network for transmitting data between modules in a communications system, wherein said data comprises periodic data and aperiodic data, said network comprising;

• a master network interface controller, wherein said master interface controller is configured (i) to allocate a first time interval for transmission of periodic data over a network databus, (ii) to dynamically allocate an aperiodic data transmission time interval, and (iii) to dynamically assign variable time slots within the aperiodic data transmission time interval for transmission of aperiodic data on said network databus;
• a first backplane coupled to said master network interface controller, a plurality of first modules coupled to said first backplane, wherein data is transmittable from one of said first modules along said first backplane to another of said first modules and said master network interface controller;
• a network databus coupled to said master network interface controller;
• at least one network interface controller coupled to said network databus;
• a second backplane coupled to said network interface controller,
• a plurality of second modules coupled to said second backplane, wherein data is transmittable from one of said second modules along said second backplane to another of said second modules and said network interface controller;
• and
• wherein:
• said first and second modules are capable of requesting transmission of said aperiodic data over said network databus, wherein said requests of transmission are dynamically prioritizable by said master network interface controller,
• said master network interface controller comprises a data transmission prioritization table, wherein said table comprises priority information regarding said aperiodic data, and
• said priority information comprises data block size and type of data, wherein said type of data comprises isochronous and asynchronous data.

A method of transmitting both periodic and aperiodic data in a network system comprising a network databus with a plurality of Network Interface Controller (NIC) modules arranged to communicate said data over said network databus, at least some of said data arriving from a plurality of devices coupled to said NIC modules through a signal backplane, wherein at least one of said NIC modules acts as a master timing NIC module responsible for allocating a first time interval for transmission of periodic data over said databus and for allocating bandwidth on said network databus, said method comprising the steps of:

• transmitting all periodic data on said network databus during said first time interval;
• transmitting requests for said master timing NIC module for transmission of aperiodic data;
• processing said requests by dynamically assigning an aperiodic data transmission interval;
• dynamically assigning variable transmission time intervals within the aperiodic data transmission interval, according to priority and availability of bandwidth on said network databus;
• transmitting a status message to said plurality of NIC modules, said status message indicating what requests are assigned bandwidth on said network databus for transmission of aperiodic data and order of transmission;
• transmitting said aperiodic data over said network databus according to said order of transmission;
• transmitting the status message to each of said NIC modules;
• and
• storing indicators in said priority tables as to what requests were assigned bandwidth on said network databus for transmission of aperiodic data and order of transmission.