Full-Fledged 10Base-T Ethernet Underwater Optical Wireless Communication System

Abstract

Marine researchers and operators during their daily work need consistent data from the underwater environment to constantly monitor the habitat’s probes and the robots condition. For underwater applications, wireless communication are of paramount importance. Today, the needs for high-speed communication has prompted the exploration of the Underwater Optical Wireless Communications (UOWC) method. This article presents the design and validation aspects of the optical layer of a bidirectional UOWC system developed in the framework of the European Project SUNRISE, able to provide wireless connectivity compliant to 10Base-T Ethernet protocol (Manchester-coded signal with 10 Mbit/s data rate). The designed modems are made of two similar optical transceivers, each including a transmitter, a receiver unit and an optical power monitor part. The transmitter is based on an array of blue Light Emitting Diodes (LEDs), the receiver exploits a commercially available Avalanche Photodiode (APD) and the monitoring relies on a pin-photodiode. The modems, after a deep characterization in controlled environments, were proved to work with the required 10Base-T Ethernet, up to 7.5 m distance in shallow harbor waters. The complete optical system is intended to become a node of the SUNRISE infrastructure

Performance analysis of OCDMA wireless communication system based on double length modified prime code for security improvement

“…Such channels can affect the optical beam propagation characteristics, leading to losses in the signal strength and changes in signal properties such as amplitude and phase [16–20]. Therefore, many channel models have been studied in the literatures to evaluate the OWC system performance [21–26]. In such models, various modulation techniques were introduced to enhance the channel performance.…”

A 30 Gb/s PAM4 underwater wireless laser transmission system with optical beam reducer/expander

“…In a highly turbid harbour underwater channel, it is vital to match the fibre collimator’s field of view of in receiver optics to maintain high transmission rates in PAM4 UWLT systems 34 . The key issue is to match the beam size to the fibre collimator’s receiving area to avoid large coupling loss and keep the high-turbidity harbour underwater link working.…”

Underwater optical wireless communications, networking, and localization: A survey

“…The research on UOWC is mainly focused on increasing the transmission range and data rate of UOWC systems. The trend to improve the data rate of UOWC systems by using light emitting diodes (LEDs) has been followed in [20]- [26].…”