High performance 1553: a feasibility study

MIL-STD-1553's one megabit-per-second data rate is adequate for the vast majority of command and control applications within avionics systems but there are emerging systems that require higher data rates. Implementing higher data rate communication generally requires the use of high speed cables. Installing new cabling in legacy aircraft can be cost prohibitive. This work explores the possibility of extending the bandwidth of MIL-STD-1553 by implementing a broadband communication system over legacy 1553 cabling. Various measurement techniques were employed by Data Device Corporation to characterize the performance of a typical 1553 network and each of its major elements. The results of these measurements are used to predict the theoretical capacity of the network using Shannon's equation. The analysis includes characterization of the signal level, noise level, and bandwidth of various channels within a MIL-STD-1553 network. The goal of the research is to quantify the amount of unused capacity within a MIL-STD-1553 system. This work does not present methods of implementing a broadband system but rather provides a framework and initial results for evaluating the feasibility of such a system. The findings presented in This work suggest that there are hundreds of megabits of theoretical capacity available in a MIL-STD-1553 network. The actual achievable data rates would depend on a number of factors including the waveform (or signal coding scheme), and the 1553 bus topology (i.e. bus length, stub length, and number of couplers). The attractiveness of a high performance 1553 system stems from the reuse of legacy cabling and the ability to add new capability to existing platforms without disturbing existing hardware and software.