Wireless communication has grown exponentially in the last couple of years. Research and technology have worked hand-in-hand to accommodate data traffic needs and are currently using 4G networks. Due to the projected demand for bandwidth-intensive media and devices, industry and academia will continue their efforts to ensure that technology keeps up with the projected need for more powerful communication networks.
Dr. Ngatched has a background in Electrical Engineering. Since he was a child, he liked to fix things, to make them work.
“My interest in engineering starts from the fact that I like solving problems. To use my imagination to create and innovate.”
Said Dr. Ngatched, who has done extensive work in digital and wireless communication systems, including underwater communications, and has received several grants throughout his career to help further his research. He recently received an NSERC grant for his project Illumination and Communication: Energy-Efficient and Secure Next-Generation Wireless Systems and Beyond.
This new research project will last for 5 years at least and will focus on using visible light communications (VLC) to address some of the requirements for the next generation wireless network referred to as 5G, wireless networks.
“it is a new communication paradigm where researchers are trying to use the light, not only for illumination, but also for communication”
VLC systems modulate the information bits and transmit the signals through light emitting diodes (LEDs) transmitters with the aid of a varied instantaneous intensity of the visible light, and at the receiver photodiodes (PDs) are used for signal detection. VLC comes with lots of benefits: financial, technical, medical, and social. Unlike radio frequency (RF) communications, VLC is safe for humans. In addition, VLC is safe for all electronic equipment, and thus can be used in RF restricted areas (e.g., airplanes, chemical plants or hospitals). Since VLC can be incorporated into existing lighting infrastructures as a complementary functionality, the technology has a ubiquitous character and a low implementation cost. Furthermore, VLC is an eco-friendly technology and provides worldwide, unregulated, and almost unlimited bandwidth.
A crucial issue facing wireless communications is the spectrum crunch problem, since most of the RF spectrum has already been allocated. That is where the spectrum of visible light, from infrared to ultraviolet, will come in to alleviate the scarcity. When Dr. Ngatched was asked if there is potential for the light spectrum to become full too, he said:
“Yes, but it will take decades. Right now it’s free and available.”
The long-term objectives of the research program are to use tools and insights from information theory, communications theory, signal processing and convex optimization to solve some of the new technical challenges in addressing the requirement for low latency and high spectrum efficiency that future wireless networks will face.
In a different project, Dr. Ngatched is investigating the use of VLC for underwater communications.
“There are three options for underwater wireless communications: radio frequency (RF) waves, acoustic waves, and optical waves.”
And the problem, according to Dr. Ngatched, is that RF waves suffer from high attenuation in water, which seriously limits the transmission range to very short distances. On the other hand, acoustic waves suffer from high communication latency and have very low transmission data rate. Thus, they cannot support high-bandwidth underwater applications, such as image and real-time video transmission. Moreover, acoustic waves have harmful effects to the marine life.
Since water is relatively transparent to light in the blue and green bands of the optical spectrum, Dr. Ngatched and many researchers believe that visible light lasers or LEDs can be used as transmitters for underwater wireless connectivity with very high data rates. The high-speed advantage will guarantee the realization of real-time applications such as imaging, underwater real-time video transmission, and high throughput sensor networks.
Written by Mayra Sanchez; Edited by Dr. Telex Ngatched.