| Name |
ADSL |
ADSL2 |
ADSL2+ |
HDSL |
IDSL |
RADSL |
SDSL |
SHDSL |
VDSL |
VDSL2 |
| Description |
Asymmetric Digital Subscriber Line |
Asymmetric Digital Subscriber Line
2 |
Asymmetric Digital Subscriber Line 2plus |
High-Bit-Rate Digital Subscriber Line |
ISDN
over Digital Subscriber Line |
Rate
Adaptive Digital Subscriber Line |
Single-line Digital Subscriber Line |
Symmetric High-Bit-Rate Digital Subscriber Line |
Very
High-Bit-Rate Digital Subscriber Line |
Very
High-Bit-Rate Digital Subscriber Line 2 |
|
ITU-T
Standard |
G.992.1 (G.dmt),
G.992.2 (G.lite) |
G.992.3 (G.dmt.bis), G.992.4 (G.lite.bis) |
G.992.5 |
G.991.1 |
|
|
|
G.991.2 (G.shdsl) |
G.993.1 (G.vdsl) |
G.993.2 |
|
Type |
asymmetric |
asymmetric |
asymmetric |
symmetric |
symmetric |
asymmetric
or symmetric |
symmetric |
symmetric |
asymmetric
or symmetric |
asymmetric
or symmetric |
| Maximum Downstream Rate |
8 Mbps (Full Rate), 1.5 Mbps (Lite) |
12 Mbps |
24 Mbps |
T1 (4-wire), E1 (6-wire) |
128 kbps |
7 Mbps |
T1/E1
(2-wire) |
2.3 Mbps (2-wire), 4.6 Mbps (4-wire) |
52 Mbps
(asymmetric), 26 Mbps (symmetric) |
100
Mbps |
| Maximum Upstream Rate |
1 Mbps (Full Rate), 512 kbps (Lite) |
1 Mbps |
1 Mbps |
T1 (4-wire), E1 (6-wire) |
128 kbps |
1 Mbps |
T1/E1
(2-wire) |
2.3 Mbps (2-wire), 4.6 Mbps (4-wire) |
6 Mbps
(asymmetric), 26 Mbps (symmetric) |
100
Mbps |
|
Coverage @ 24 AWG |
12,000 feet
(Full Rate)
18,000 feet
(Lite) |
18,600 feet |
22,000 feet |
12,000 feet |
18,000 feet |
18,000 feet |
10,000 feet |
11,000 feet |
5,000
feet |
12,000
feet |
|
Line coding |
DMT |
DMT |
DMT |
2B1Q/CAP |
2B1Q |
CAP |
2B1Q/CAP |
TC-PAM |
DMT |
DMT |
|
POTS (telephone) presence in the same line |
yes |
yes
or no |
yes
or no |
no |
no |
yes |
yes |
no |
yes |
yes |
Notes:
- xDSL means any type of DSL.
- symmetric means having the same downstream and upstream rates.
- asymmetric means having the downstream rate that is faster than upstream rate.
- ITU-T : International Telecommunication Union
Telecommunication Sector
- Existing standard of VDSL is ANSI T1E1.4
- T1 (1.544 Mbps) is used in North America and Japan. E1 (2.048 Mbps) is used in Europe and other countries.
- 1 line = 1 pair of copper wires or 2 copper wires; 2 lines = 4 wires; 3 lines = 6 wires
- AWG : American Wire Gauge; 24 AWG has 0.5 mm diameter
- Line coding : DMT, CAP, 2B1Q
- TC-PAM: Trellis Coded - Pulse Amplitude Modulation.
- POTS : Plain Old Telephone Service
|