SBIR-STTR Award

This effort will continue the development of an optical analog microphone initiated on a previous SBIR program and will also include a feasibility study of various methods of providing total digital voice signal distribution of interphone communications between positions and with radios. the performance benefits of including the digital conversions in the headset vs. converting in the "box" that the headset plugs into will be evaluated in a simulated noise environment. The final report will quantify the performance of the digital headset and will recommend a design and a testing methodology to be demonstrated in Phase II. The second part of the Phase I effort will involve a study of the whole intercom/radio system, including the control functions necessary for call initiation and termination. A key part of the study will develop a Performance Index to be sued to compare and rate the effects of using various communications protocols. Factors to be included in the Index will be voice quality, operational use of the system, reliability and maintainability, equipment form factors, and costs; protocols to be considered will include various isosynchronous and time sensitive "standard" protocols such as FDDI II, ATM, 100Base-VG, Isosynchronous Ethernet, and FFOL as well as a synthesized unique protocol that is customized for digital shipboard or aircraft intercom/radio systems. To arrive at the rating factors that are incorporated in the Performance Index, the Navy Program office and field operators will be consulted. A final report will summarize relative benefits and will recommend a Demonstration model to be implemented in Phase II. This Digital Voice Signal Distribution of Crew Communication study and demonstration will be performed by a joint venture partnership of Micro Optics Inc., the developer of the digital headset, and TechnoSys, Inc., the developer of the Distribution System. The synergism of this partnership will take advantage of the expertise in physics and optics offered by Micro Optics and the Voice communication Systems experience provided by the engineers at TechnoSys. The joint venture partnership will remain in existence through the commercialization and production of the system in Phase III.

Keywords:
Digital Headset Digital Intercomm Isosynchronous Protocols Optical Transducer Noise Cancelling

This effort will continue the development of the acoustic-to-optical analog microphone first conceived on a prior SBIR contract and demonstrated with a digital interface in Phase I. Microphone noise cancellation will be extended to at least 13 dB using a combination of optical design techniques and noise reduction algorithms implemented in the Voice Control Module DSP. In addition, a very high noise-immunity interface to the headset earphones will be developed using either digital or optical transmission; an optical interface will be implemented if the optical earphone investigation and preliminary design performed on a current USAF grant proves feasible and offers size and weight advantages. Otherwise, a digital interface will be provided and the conversion and amplifier circuitry on the headset, optimized. Optical-acoustic earphones and an acoustic-optical microphone would allow the highest RFI/EMI noise immunity possible and the associated headset size and weight is anticipated to be smaller and lighter than for conventional headsets. The Distribution system, which performs call establishment, call conferencing and transmission of audio and control data between positions, will be developed and a prototype implemented. The prototype will be developed around an Open System architecture and will be constructed in a modular fashion, allowing the system to be operated with several different standard network protocols such as Fiber Channel, Ethernet, Fast Ethernet, and FDDI. COTS hardware will also be employed to the maximum extent possible. The prototype system will consist of an "Avionics" Position and a "Commercial" Position, interconnected via an Ethernet-based fiberoptic backbone bus. Each Position will be equipped with the headsets described above; The Avionics Position will also include a digital CVSD radio interface and a simulated radio. The prototype performance will be evaluated under variable bus loads by using a second PC workstation to generate a variable number of packets that will be transmitted over the bus to the first PC. This interchange of data packets will also demonstrate the compatability and coexistence of the Digital Voice Distribution System in systems where other users could b

Keywords:
Acoustical/Optical-Headsets Digital-Audio Voice-Over-Ethernet Intercomm Conferencing Interphone