Two high-speed angle diversity optical wireless systems have recently been implemented, as part of a European Community funded project. One operates at 1.25 Gb/s offering a limited coverage area, and the other at 280 Mb/s, with room scale coverage. In this paper, we summarize the design approach for these systems and their performance. Implications of these results for the design and implementation of future systems are also discussed.

The European project "hOME Gigabit Access Network" (OMEGA) targeted various wireless and wired solutions for 1 Gbit/s connectivity in Home Area Networks (HANs). One objective was to evaluate the suitability of optical wireless technologies in two spectral regions: visible light (visible-light communications - VLC) and near infrared (infrared communications - IRC). Several demonstrators have been built, all of them largely relying on overthe- shelf components. The demonstrators included a "wide-area" VLC broadcast link based on LED ceiling lighting and a laser-based high-data-rate "wide-area" IRC prototype. In this paper we discuss an adapted optical-wireless media-access-control (OWMAC) sublayer, which was developed and implemented during the project. It is suitable for both IRC and VLC. The VLC prototype is based on DMT signal processing and provides broadcasting at ~ 100 Mbit/s over an area of approximately 5 m2. The IRC prototype provides ~300 Mbit/s half-duplex communication over an area of approximately 30 m2. The IRC mesh network, composed of one base station and two terminals, is based on OOK modulation, multi-sector transceivers, and an ultra-fast sector switch. After a brief discussion about the design of the optical-wireless data link layer and the optical-wireless switch (OWS) card, we address the card development and implementation. We also present applications for the VLC and IRC prototypes and measurement results regarding the MAC layer.

During the European collaborative project OMEGA, two optical-wireless prototypes have been developed. The first prototype operates in the near-infrared spectral region and features Giga Ethernet connectivity, a simple transceiver architecture due to the use of on-off keying, a multi-sector transceiver, and an ultra-fast switch for sector-to-sector hand over. This full-duplex system, composed by one base station and one module, transmits data on three meters.The second prototype is a visible-light-communications system based on DMT signal processing and an adapted MAC sublayer. Data rates around to 100 Mb/s at the physical layer are achieved. This broadcast system, composed also by one base station and one module, transmits data up to two meters.In this paper we present the adapted optical wireless media-access-control sublayer protocol for visible-light communications. This protocol accommodates link adaptation from 128 Mb/s to 1024 Mb/s with multi-sector coverage, and half-duplex or full-duplex transmission.

The hOME Gigabit Access (OMEGA) home-area-network project aims at bridging the gap between home and access network and providing Gb/s connectivity to users. The project considers a combination of various technologies such as radio-frequency and wireless optical links operating at infrared and visible wavelengths. When combined with power-line communications (PLC), this enables a home backbone that meets the project's "without new wires" vision. A technology-independent MAC layer will control this network and provide services as well as connectivity to any number of devices the user wishes to connect to in any room of a house/apartment. In order to make this vision come true, substantial progress had to be achieved in the fields of optical wireless physical layer development and data-link-layer protocol design. This paper reports an experimental demonstration of an indoor visible-light wireless link including a MAC layer protocol adapted to optical wireless communications systems. The system operates at 84 Mb/s broadcast and was successfully used to transmit three highdefinition video streams.