DSL Technologies
ADSL
Asymmetric Digital Subscriber Line
ITU G.992.1 – G.DMT – 8.0Mbit/s, 1.0Mbit/s
ITU G.992.2 – G.Lite – 1.5Mbit/s, 0.5Mbit/s
ITU G.992.3/4 – ADSL2 – 12Mbit/s, 1.0Mbit/s
ITU G.992.5 – ADSL2+ – 24Mbit/s, 1.0Mbit/s
SDSL
Symmetric Digital Subscriber Line
SHDSL
Symmetric high-speed digital subscriber line
ITU G.991
VDSL
Very high bit-rate Digital Subscriber Line
ITU G.993.1 – VDSL
ITU-T G.993.2 – VDSL2
Signal Level Guide
ADSL
Downstream SNR = 15 dB.
Higher is better, minimum = 6 dB.
Downstream Power = < 15 dBm.
Lower is better.
Upstream SNR = 10 dB.
Higher is better.
Upstream Power = < 15 dBm.
Lower is better.
Downstream Attenuation = < 30 dB
Lower is better, maximum = 60 dB.
Upstream Attenuation = < 30 dB
Lower is better, maximum = 60 dB.
ADSL2+
Downstream SNR = 06 dB.
Higher is not better. Within range is better = 05 – 07 dB.
Downstream Power = < xx dBm.
Lower is better.
Upstream SNR = 06 dB.
Higher is not better. Within range is better = 05 – 07 dB.
Upstream Power = < xx dBm.
Lower is better.
Downstream Attenuation = < 22 dB
Lower is better, maximum = 22 dB (for 10mbps), 12 dB (for ~25mbps).
Upstream Attenuation = < 22 dB
Lower is better, maximum = 22 dB (for 10mbps), 12 dB (for ~25mbps).
Attenuation to Loop Length Conversion
10 dB ~ 0500 m
15 dB ~ 1000 m
25 dB ~ 2000 m
35 dB ~ 2500 m
NOTE
All readings are based on CPE, with average error margin of CPE taken into considerations.
