ADSL2 and ADSL2+ technologies have enabled ISP providers to provide their customers with high-speed broadband via legacy copper lines. We've compiled a list of the 11 most commonly asked questions about ADSL2 & ADSL2+ to demystify the Digital Subscriber Line (DSL) technologies. If you’re interested in learning more about VDSLs, visit our VDSL/2 FAQ here.
1. What is ADSL2/ADSL2+?ADSL2 and ADSL2+ are DSL technologies that deliver high-speed broadband using Plain Old Telephone Services (POTS). Copper telephone wires consist of at least 25 or more twisted wire pairs making transmission signals susceptible to crosstalk. ADSL2 and ADSL2+ utilize sophisticated modulation technologies to eliminate noise and interference in transmission signals. This allows for relatively error-free transmission via legacy copper lines.
2. How fast is ADSL2?Actual speeds vary depending on networking environments and copper loop lengths. ADSL2 can achieve downstream data rates of up to 12 Mbps speeds at its source while ADSL2 can achieve up to 24 Mbps. ADSL2/2+ are best suited for longer loop lengths. ADSL2 can reach distances of up to 5,000 meters while ADSL2+ can achieve up to approximately 6,000 meters.Refer to the chart below to compare ADSL2, ADSL2+, and VDSL2 speeds.
3. What is the farthest ADSL2/2+ can reach?ADSL2 can reliably support high-speed broadband to loop lengths as far as 5,000 meters while ADSL2+ can achieve slightly longer distances at 6,000 meters.
4. What are some ADSL2 improvements?ADSL2 improves:
- Modulation Efficiency
- State Machine Initialization
- Coding Gain
- Signal Processing Algorithms
- Framing Overhead Reduction
- Seamless Rate Adaptation (SRA)