Hybrid Wireless Networking

Development of hybrid optical and radio frequency network for mobile and temporary applications, including disaster recovery and environmental monitoring.

hybrid optical network

Dr. LoPresti and his collaborators received a $300,000 grant from the National Science Foundation to develop the technologies needed to construct a free-space (wireless) network using both optical and radio-frequency links. The outcome of the project will be the commercialization and product development of disaster area wireless network (DAWN). The NSF funds are used to carry out the following research tasks.

  1. The development of viable physical layer connectivity between balloons using hybrid free-space optical (FSO) and radio frequency.
  2. The development of receiver access control (RAC) protocols, allowing the sharing of receivers among multiple FSO nodes.

The development of routing algorithms and topology design that facilitates a self-configuring FSO ring topology with an RF link for inter-nodal communications, as well as backup capacity when FSO links are unavailable. Routing protocols will maximize the throughput of the network and minimize blocking probabilities through the use of multi-homing and a cross-layer approach.

The problem addressed by Dr. LoPresti’s work is the integration of the systems responsible for node stabilization with systems controlling the alignment of the FSO physical layer. Even with sophisticated acquisition, alignment and tracking systems in place, prior work has shown that the performance of such systems are enhanced by knowledge of the current location and likely future locations of the optical transceivers. Research efforts will focus on interfacing the stabilization system with innovative transceiver systems currently under development by the investigators. We will investigate the use of raw position data, statistical data on motion, and control data from the stabilization system for selecting appropriate settings for the optical output power, beam divergence, and steering angle. The goal is to increase the connection probability and duration of a viable FSO link by proactively adapting the connection parameters to accommodate expected changes in the communication channel.

Specific work will involve the following tasks:

  • Identification and acquisition of information and signals relevant to the alignment process for FSO transceivers.
  • Determining what processing is required on the signals to provide useful information to the transceiver.
  • Formatting of information into signals for controlling the alignment of the transceiver.
  • Experimental and simulation based evaluation of designs that are developed.

Translating the most promising design(s) into a form appropriate for commercialization