Moritz Röger

Optically powered fiber networks

Optically powered networks are demonstrated. Heterogeneous subscribers having widely varying needs with respect to power and band-width can be effectively controlled and optically supplied by a central of-fice. The success of the scheme relies both on power-efficient innovative hardware and on a novel low-energy medium access control protocol. We demonstrate a sensor network with subscribers consuming less than 1 microW average power, and an optically powered high-speed video link transmitting data at a bitrate of 100 Mbit/s.

An Optically Powered Video Camera Link

An optically powered camera sensor link is demonstrated. Power and data are transmitted over a 62.5-?m multimode glass fiber. Uncompressed video with 640 × 480 pixels resolution is streamed continuously at 100 Mb/s as soon as the fiber is illuminated with sufficient optical power. No energy has to be stored at the sensor location in batteries with limited capacities and lifetimes. Inexpensive fiber optics and low-power state-of-the-art electronics are used to make >100 mW available at sites which have no direct access to an electrical network. There is a complete electrical isolation between the remote camera unit and a base station.

Optically Powered Video Camera Link

An optically powered camera sensor link is demonstrated. Power and data are transmitted over a 62.5-¿m multimode glass fiber. Uncompressed video with 640 × 480 pixels resolution is streamed continuously at 100 Mb/s as soon as the fiber is illuminated with sufficient optical power. No energy has to be stored at the sensor location in batteries with limited capacities and lifetimes. Inexpensive fiber optics and low-power state-of-the-art electronics are used to make >100 mW available at sites which have no direct access to an electrical network. There is a complete electrical isolation between the remote camera unit and a base station.

An optically powered fibre network for heterogeneous subscribers

In optically powered networks, glass fibres are used for transmitting optical communication signals as well as optical energy for electrically powered devices. Advantages over existing power delivery technologies are: immunity to electromagnetic interference, spark-free power for safety-critical applications, slim cables, simple installation and reduced maintenance cost. Applications relate to security of public spaces and buildings, down-hole exploration, medical endoscopes, and to communications in the context of remote RF antennas and passive optical networks (PON). An optically powered network can connect widely differing subscribers with low/high bandwidth requirements, asynchronous/synchronous operation, and low/high priority, e.g., energy-preserving small-bandwidth subscribers with ultra-low duty cycles and low network priority (e.g., temperature sensors) in combination with wide-bandwidth subscribers operating at large duty cycles and high priority (e.g., video conferencing). Optical energy is supplied centrally from an access point, and this results in a combined star and tree-like network topology. As a consequence, subscribers communicate with the CO only, and therefore a standard carrier sense multiple access (CSMA) protocol cannot handle the data exchange. We present optically powered subscriber hardware and demonstrate a low-energy medium-access control (LE-MAC) protocol that extends the IEEE 802 standard, allows random and scheduled medium access of subscribers, and, by quality-of-service support, efficiently uses the available resources, namely channel bandwidth and optically supplied energy.

Reconfigurable Hardware for Power-over-Fiber Applications

In this paper we present an optically powered and motorized video camera system. Energy for the camera sensor is supplied by a glass fiber carrying 800 mW of optical power, which the sensor converts back to 320 mW of electrical power. The specific advantage of this arrangement is galvanic isolation and a very high robustness with respect to electromagnetic interference. We demonstrate that sufficient energy can be transmitted for driving an Actel Igloo FPGA, which performs the necessary signal processing. Additionally, with the help of capacitive energy storage, some small actuators can be supplied which move the camera sensor head. The base station of the system, based on a Xilinx Virtex-5 FPGA, holds a LEON-3 based system-on-chip encoding the incoming VGA video stream into Motion-JPEG formatted data in realtime, which may be directly sent to the internet using an Ethernet interface. The prototype has numerous fields of application where it performs much better than stateof-the-art solutions. Most prominent examples are visual sensors in high voltage areas as well as medical endoscopes.