FM3TR Parameterisation


The Future Multiband Multiwaveform Modular Tactical Radio (FM3TR) is a multi-national collaboration to create a modern unclassified communication waveform, that can be used to test interoperability between two different Programmable Digital Radio platforms. The waveform addresses the issues of:

A summary of the FM3TR work may be found at http://millerlab.ucsf.edu/emondi/Public/FM3TR/FM3TR_Summary.html.

Example Parameterisation

The FM3TR waveform has been used extensively throughout the Phase 1 work as it provides a good example of a modern waveform, which has exercised the language currently under development. As the final WDL is expected to be issued as an open standard, a tutorial example of a waveform parameterisation is required. FM3TR will fill this role.

FM3TR Parameterisation

The first task in parameterisation of FM3TR is to identify the main specification structure. The top level entity shows all external interfaces identified by the specification.

The next layer of decomposition identifies the FM3TR protocol layers and, hence, the main structure of the specification. The FM3TR radio specifies a realisation of the lower three layers of an OSI protocol stack using four layers: Network (Nwk), Data Link Control (Dlc), Medium Access Control (Mac) and Physical (Phl). The FM3TR specification identifies a variety of configuration and operation parameters, but does not specify their interface. An Hci entity is therefore introduced to terminate these unspecified interactions.

The Phl layer supports transmission of either the CVSD voice_in or tx packets and corresponding reception to produce voice_out or rx packets. Further decomposition of the physical layer entity partitions the required behaviour into seven more manageable elements.

Configuration of the layer is provided through an hci message interface that the Hci entity decodes to provide control of carrier detect response and synchronisation robustness. Transmit and receive statistics may be interrogated. A packet interface is provided by the Rx and Tx entities, with the Cd entity providing a carrier_detect signal for use by the pCSMA algorithm in the MAC layer.

Multiplexing of transmit and receive signals to the antenna is provided by the Radio entity

Debounce filtering of the Push To Talk signal that accompanies the voice input is provided by the Ptt entity.

The TransSec entity is not specified by FM3TR, but it must clearly supply information to the Fsm that switches between the different operational modes of the physical layer.

The majority of the behaviour is state dependent and is therefore provided within one of the three exclusive behaviours governed by the Fsm entity.

Assuming half duplex operation, the FSM idles in the Rx state, entering either VOICE_TX or DATA_TX in response to an appropriate transmit request. Entry to RX issues a reset (to the PTT monostable). Each state specifies potentiall distinct receive and transmit activity, although the TxModulator is reused for both data and voice transmission.

The decomposition process continues until leaf entities are identified. Leaf entities at the bottom level can consist of two fundamental types. Those defined in the WDL Primitives Library, which are generic entities likely to be used by other specifications, or entities specific to the current specification. Leaf entities will contain a mathematical expression. A completed parameterisation would be contained within the WDL tool set, with auto generated HTML based text providing a full description of the parameterisation. Details of all waveform specific leaves would also be included in the parameterisation documentation.

The full FM3TR Decomposition is available.


Last updated 01 Febuary 2001