The SIMPLE defines a communications protocol to provide the means for geographically separated Tactical Data Link equipment to exchange environment data and TDL messages in order to conduct detailed TDL Interoperability testing. It is intended to provide specifications for a common standard to interconnect ground rigs of all types, such as simulation and integration facilities. The SIMPLE allows transmission of M-Series and J-Series messages over IP-based protocols. Previously J-Series messages could be sent using the Link 16 protocol. However, Link 16 is a radio protocol with a frequency range that limits the exchange of information to within line-of-sight. Use of flexible bearer protocols, such as IP, makes it easier to exchange such J-Series data, particularly for simulations and integration. However, the SIMPLE is not limited to use for simulation and integration, and is finding applications beyond its original purpose wherever transmission of J-Series data is not amenable over radio protocols such as Link 16.
The SIMPLE standard specifies the distributed transfer of a simulated scenario/synthetic environment using the IEEE Distributed Interactive Simulation protocols. DIS is a government/industry initiative to define an infrastructure for linking simulations of various types at multiple locations to create realistic, complex, virtual worlds for the simulation of highlyinteractive activities. A new Protocol Data Unitdefinition, the DIS PDU was added to the baseline protocol to support the exchange of DIS PDUs for simulated entities. The content of the SIMPLE DIS PDU packet is related to the DIS PDUs defined in the IEEE 1278.1 standard. As such, most Transmitter and Signal PDU fields require no translation.
Structure of the SIMPLE protocol
The SIMPLE standard consists of several elements. These are:
The SIMPLE is an application layer protocol that is designed to be independent of the transport layer. It can run using the following transport layer protocols:
In SIMPLE, the method for exchanging TDL messages is to take the host generated message traffic from the MIDS/JTIDS terminal interface and repackage it for transmission across the SIMPLE network. The receiving SIMPLE node extracts the TDL message traffic from the received packet and presents it to the host interface as if it had been received from a MIDS/JTIDS terminal.
