Hiroshi Takatori, Chief Technology Officer, KeyEye Communications
Simultaneous bidirectional transmission (SBT) has been repeatedly proven as the ultimate technology for noisy, band-limited channels in ISDN, HDSL, HDSL-2, and 1G Ethernet. The key to using this technique in backplanes is to develop multi-gigahertz echo cancellation using common CMOS technology. When full duplex transmission is combined with multi-level PAM, the signaling rates across the backplane can be 1/4 to 1/8 that of the data rate (@BER 10-18) with little change in power. This paper will include a performance comparison of the available backplane technologies in real-world environments, give a high-level overview of the implementation requirements for SBT in silicon, and offer measurements made from the industry's first 10-Gbps simultaneous bidirectional device.