Key characteristics of the USB 3.2 solution include:

Two-lane operation using existing USB Type-C? cables
Continued use of existing SuperSpeed USB physical layer data rates and encoding techniques
Minor update to hub specification to address increased performance and assure seamless transitions between single and two-lane operation

For example, a USB 3.2 host connected to a USB 3.2 storage device will now be capable of realizing over 2 GB/sec data transfer performance over
　an existing USB Type-C? cable that is certified for SuperSpeed USB 10 Gbps.

ＵＳＢ３．２　１０Ｇｂｐｓ　２レーン　＝２０Ｇｂｐｓ？
ＵＳＢ３．１　１０Ｇｂｐｓ
ＵＳＢ３．０　　５Ｇｂｐｓ


Thunderbolt 3 2015年6月　全二重　１レーン 40Gbps ×2（双方向）　×1レーン　2m（電線）　60m（光ファイバー）

Thunderbolt　Ｇｅｎ２　２０Ｇｂｐｓ
Thunderbolt　Ｇｅｎ１　１０Ｇｂｐｓ

Beyond Thunderbolt 3
will have to increase the bandwidth still further, probably taking the standard up to 80 Gbit/s (10 GB/s).

Thunderbolt 3がやたらと速いけど、これの物理層はどうなってるの？

高速伝送のための信号補正用チップが組み込まれており、とあるが。