![](https://csdnimg.cn/release/download_crawler_static/14915255/bg6.jpg)
2-16 4 4
A 111 1111 1 B 11 1 111 1 1
C 11 1 111 1 1 D 11 1 111 1 1
S 113 1131 1
0 1
S?A= 11 311311 8=1 A 1
S?B= 1 1 311 3 11 8=1 B 0
S?C= 1 1 311 3 11 8=0 C
S?D= 113113 11 8=1 D 1
2-17 xDSL HFC FTTx
xDSL
HFC
450 MHz 750 MHz HFC
FTTx x
2-18 ASDL 1MHz
DMT
3-01 ( ) ( ) ?
?
3-02 ? .
3-03 ? ?
TCP/IP
OSI
3-04 ( )
3-05
3-06 PPP PPP PPP PPP
A 0xFF
C 0x03PPP PPP