Prof. Danny H.K. Tsang ECE, HKUST

Prof. Danny H.K. Tsang
• Joined HKUST in May 1992
• For contribution to the optimization of communications networks
• Research on efficient delivery of multimedia traffic over different networks
•ATM networks
•CDN and P2P networks
•WiFi networks (IEEE 802.11e)
•Optical networks (SONET/SDH)
• Invent 64B/65B encoding in 2000
• In 2001, the invention was adopted by the International
Telecommunication Union (ITU - 國際電信聯盟)’s Generic Framing
Procedure recommendation GFP-T (ITU-T G.7041/Y.1303)
• In 2005, the invention obtained a US Patent number 6,952,405
64B/65B Encoding
• Fiber Channel and Gbit Ethernet (以太網) use 8B/10B encoding to achieve
clock synchronization (only 80% efficiency or 20% bandwidth waste)
• In 8B/10B, there are a total of 256 possible data and 12 possible controls (i.e.,
a total of 268 possible data/controls)
The 64B/65B Invention
• For the delivery of 8B/10B data/controls over SONET/SDH, we take advantage
of SONET/SDH having very accurate clock, and we just propose an efficient
method to represent the 268 possible data/controls
• Achieve an efficiency of 64/65 (98.5% efficiency or 1.5% bandwidth waste)
Less bandwidth waste  less network congestion  happier users