Embedded Software

TIMING & FREQUENCY SYNCHRONIZATION SOFTWARE — Designed and implemented embedded timing and frequency synchronization software for a satellite base station. This core feature of the Satellite Base Station synchronized the transmitting and receiving time and frequency for traffic/control channels. The following types of synchronization were implemented: synchronization to a common reference signal; between Gateway and satellite; between Gateways; and between User Terminal and satellite. The Sheller-Miller method was used to create an object-oriented design which was implemented on VxWorks in C. The software supports TDMA technology and the GSM protocol.

T1 INTERFACE CARD FOR SATELLITE TELEPHONY SYSTEM — Developed embedded software for a T1 interface card as part of a satellite telephony system, which included the following functionality: drivers for flash memory devices, including hardware drivers and a blocked file system, a boot controller to control the overall booting process from a boot ROM, a network downloader to download software into flash memory over an Ethernet interface, a serial interface driver to interface hardware connected via multi-drop interface, and satellite downline load, which allowed the unit to receive software and configuration data via satellite.

VIDEO CONFERENCE SYSTEM — This project involved design and implementation of a real-time operating system responsible for task management, interrupt setting, and control of slave processors for a videoconference system over a commercial satellite link. The project included development of software for TDMA frame synchronization and timing, aperture control for burst detection, voice and video data management, synthesizer control for frequency tuning, and hardware register control.

WIDE AREA NETWORK SWITCHING EQUIPMENT SOFTWARE — Full software support of a complete line of WAN digital switching products. These products are used extensively around the world in both carrier and enterprise networks. Supported software includes proprietary switching, routing, and operating system software, as well as a number of access and trunking protocols, including Frame Relay, X.25, ISDN, and X.28.

MOBILE TERMINAL STATION — Designed and implemented a mobile terminal station for communications over the INMARSAT Standard-C communications system. The software was developed in C for an embedded Intel 8031 microprocessor.

FLASH MEMORY SUBSYSTEM — Designed and built a Flash memory subsystem in a real-time embedded satellite telecommunications system. The subsystem consisted of a layer of code which provided simplified access to the Flash memory.

ATM TRAFFIC CONCENTRATOR — Enhancements to the embedded application software of a Traffic Concentrator System being developed for an ATM-based Video-on-Demand network. The embedded application software consisted of software that would provide redundancy and failure-protection to ensure several thousand uninterrupted SVC connections and corresponding high-speed ATM data traffic through the system in the event of a failure on any one of the two redundant ATM switching boards on the system.