Project Description and Outcome

Ideas

The University of Maryland, College Park, has developed a remote, real-time surveillance system to demonstrate the ultra-broadband capability of hybrid Free Space Optical (FSO)/RF links. Our system transmits ultra-high bandwidth, high resolution images from surveillance cameras monitoring regions of interest on campus. Hybrid wireless links transfer live, high resolution, video imagery that can be processed in real time to provide important information about targets of interest in the field of view. Targets of interest can be “events” detected by intelligent image analysis software, moving vehicles, or background changes in the field of view. This requires high quality, both in terms of spatial resolution and in the time domain (frame rate), which demands a large bandwidth. An important feature of our system is that it provides transmission of high-resolution imagery, which requires low latency, high data-rate frame transfer end-to-end over the Internet, with wireless communications in the “last mile.”
Our system, which includes high resolution, zoomable, tracking cameras, with 1.25Gb/s FSO and 100Mbs 24GHz directional RF links, can remotely process incidents over an internet and execute follow up activity such as tracking in real time. The average data transfer rate for this application is approximately 183Mb/s, corresponding to slightly less than 15% of total available bandwidth.

Tools

The University of Maryland has developed revolutionary hybrid, broadband wireless, combined free space optical (FSO) (laser communication) / radio frequency (RF) networks with topology control. Such networks provide high-speed Internet access to fixed infrastructures (commercial, residential, educational) for such applications as homeland security, education, e-commerce, e-science, telemedicine. They also provide a rapid deployment capability (e.g., emergency vehicles) for homeland security, disaster recovery and emergency response. The key technologies involve establishing and maintaining: 1) the highly directional FSO/RF beams between two nodes (i.e., switches, routers, base-stations) and 2) the connectivity and quality-of-service (QoS) throughout the network in response to degradation. This research is driven by the need to provide truly broadband (up to Gb/s and higher) to mobile users and to fixed users who are not connected to the fiber backbone infrastructure (the first/last mile problem). The unique technology combines autonomous backbone formation with assured, agile, optical wireless and RF links. Our research in autonomous reconfigurability of hybrid wireless networks has shown that robustness, quality of service and fault tolerance can be achieved because of the media diversity and topology control. In addition, optical wireless communications, with data rates of up to 1 Gb/s, offer great promise for scalability and broadband, multimedia service in contrast to the constraints of RF communications.
Conventional wireless connectivity is limited in bandwidth, has poor security, and is rapidly running out of available spectrum. FSO technology promises to offer a bandwidth approximately 20,000 times greater than the current high-speed Internet wireless bandwidth and 1,000 times greater than cable or DSL bandwidths in the communications “last mile.”
Surveillance of the nation’s critical infrastructure -- roads, buildings, water storage and distribution systems, electrical, rail and environmental systems –has become a critical component of homeland security efforts. Keeping military and law enforcement officials and disaster management teams adequately informed as they initially respond to hazardous spills, major weather events or terrorist related activities is equally important.
The broadband wireless networking of sensors for surveillance and intelligence has emerged as a significant research and development thrust. The focus of the Center is on research and development aimed at new network architectures, protocols, and technologies for infrastructure sensing, with an emphasis on very high data transmission.