Impact of time delays on the JTIDS network

ITT Avionics has developed the intermediate processor (IP) to act as a gateway device for connecting a host tactical data system (TDS) to its associated C² communications terminal. Originally developed for JTIDS interoperability testing the intermediate processor has evolved into a generic product which can act as a virtual host to a C² communications terminal and as a virtual terminal (VT) to a host TDS. In this manner, the terminal and its host can be physically remote from one another and operate as if they were directly connected. One of the major concerns with this method of remoting the JTIDS terminal from its host TDS is the time delays incurred by sending the TDI data the extended distance. End-to-end timing analysis shows that information transferred between a host system and its associated JTIDS terminal will experience time delays ranging from 40 ms to 100 ms depending on the packet size and distance (telephone routing) between the VH and VT communicating over a 64 Kbps DDS link. It is shown that time delays experienced while utilizing the IP to support the decentralized methodology for testing the interoperability of JTIDS-equipped host TDSs, as well as while utilizing the (IP) in a combat environment to remote the JTIDS terminals as far forward in the battle area as possible, have no impact on the operational effectiveness of the community of host TDSs using Class 1 or Class 2 JTIDS terminals