Researchers at the University of Oxford claim to have reached a Li-Fi milestone by achieving bi-directional speeds of 224 gigabits per second (Gbps).
The Oxford University researchers published their research work in the IEEE Photonics Technology Letters journal and described an indoor optical bidirectional wireless link with an aggregate capacity over 100 Gb/s. The link operates across ~3 m range at 224 Gb/s (6 x 37.4 Gb/s) and 112 Gb/s (3 x 37.4 Gb/s) with a wide field of view (FOV) of 60° and 36°, respectively. The researchers believe it is the first demonstration of a wireless link of this type with a FOV that offers practical room-scale coverage. The researchers achieved the performance by developing specialized broadcast LEDs and receivers operating with different fields of view and bands that affect the data transmission speeds.
Dominic O'Brien, lead researcher and photonics engineer at Oxford University, described the technology working in a similar way to projectors and the research team are working to incorporate tracking technology into the system so that the light can locate the computer wherever it is placed in a room.
Li-Fi is only able to work within line of sight which means a computer would need to be in a fixed position for now. The speed is also dependent on the receiver's field of view. With a 60-degree field of view, the researchers were able to transmit six wavelengths of 37.4 Gbps each, for an aggregate bandwidth of 224 Gbps. When the field of view was narrowed down to 36 degrees, the researchers transmitted only three wavelengths for an aggregate bandwidth of 112 Gbps.
The researchers believe optical fiber communication networks have the potential to provide terabit aggregate capacities to buildings and offices within modern cities and point out that existing practical wireless systems are orders of magnitude below the capacity possible with Li-Fi technology.
Currently Internet users Wi-Fi technologies operating to Wi-Fi 802.11ac are only able to transfer data at between 7 Gbps tp 10 Gbps.
