Professor Raymond Yeung of The Chinese University of Hong Kong (CUHK) has pioneered network coding, a major breakthrough in information science which makes network communications more efficient, reliable, stable, and secure.
Network coding is a networking technology in which transmitted data is encoded and decoded to increase network throughput and reduce delays, making the network more robust.
Professor Yeung’s revolutionary research has far-reaching impact not only on wireless communications and the internet but also in the aerospace industry. His textbooks on information theory and network coding have been adopted by more than 100 universities worldwide.
A recipient of numerous international awards, Professor Yeung gave the world’s first MOOC (Massive Open Online Courses) on information technology in 2014, enlightening more than 25,000 students from around the world on this leading technology.
Giants of Science
CUHK has been a forerunner in telecommunications since half a century ago when then Vice-Chancellor Professor Charles K. Kao founded the Department of Electronic Engineering. Known as the Father of Fibre Optics, Professor Kao was awarded the 2009 Nobel Prize in Physics for developing the ground-breaking optic fibre technology that transformed the way the world communicates.
At CUHK, Professor Kao built a long-term strategy focussing on electronic engineering as well as information and communication technologies, helping it stay ahead of its peers worldwide across the decades.
In 2010, CUHK established the Institute of Network Coding with funding of more than HK$80 million (equivalent to US$10.3 million) from the Hong Kong Government-funded Areas of Excellence scheme, the largest engineering research project ever funded in the territory.
The institute conducts cutting-edge research on network coding and its use in internet communications, wireless communications, information security, data storage, and bioinformatics, strengthening Hong Kong’s status as an international research centre in the field.
In its latest work, Professor Yeung’s team has put forward the BATched Sparse Code – known as BATS codes – a sophisticated network coding technique which overcomes the problem of data loss in multi-hop wireless transmission and offers higher speed, reliability and stability.
BATS codes offer less complex encoding and decoding than conventional random linear network coding, and require a much lower buffer size at the intermediate nodes. For example, for a multi-hop network with three hops and a 20% rate loss per hop, BATS code can increase the transmission rate by 56% and reduce the loss rate by 29%. The advantages of BATS codes become even more pronounced when the number of hops increases.
The technology has already resulted in patents from a number of different countries and Professor Yeung’s team is now working towards its future applications for 5G wireless communications, satellite communications, the Internet of Things, and wireless sensor/mesh networks.
Looking ahead, Professor Yeung hopes to further enhance Hong Kong’s leading position in network coding, making Hong Kong a premier network coding centre by maintaining a world-class research team with comprehensive expertise in all areas of network coding.
The work of the Institute of Network Coding has led to other major discoveries in the field of communications. Co-director Professor Liew Soung-chang and his team have hit on a way of speeding up wireless networks that slow down when they are logged into by multiple users.
They developed the revolutionary Physical-layer Network Coding (PNC) which significantly improves the capacity and energy efficiency of wireless networks by tackling the wireless interference problem.
PNC turns interference into an advantage by harnessing the hidden useful information contained in the interference, allowing multiple devices to transmit messages simultaneously without the usual slowing down.
“Compared with conventional schemes, PNC can accommodate a larger number of wireless devices in a wireless network without sacrificing the speed,” Professor Liew explained. “PNC efficiently addresses the interference bottleneck problems in wireless networks, leading to a dramatically improved system throughput by 100%.” PNC has immense application potential, including earth-to-space communications.