Digital Subscriber Line Access Multiplexer - Bandwidth Versus Distance

Bandwidth Versus Distance

Balanced pair cable has higher attenuation at higher frequencies, hence the longer the wire between DSLAM and subscriber, the slower the maximum possible data rate. The following is a rough guide to the relation between wire distance (based on 0.40 mm copper and ADSL2+ technology) and maximum data rate. Local conditions may vary, especially beyond 2 km, often necessitating a closer DSLAM to bring acceptable bandwidths:

• 25 Mbit/s at 1,000 feet (~300 m)
• 24 Mbit/s at 2,000 feet (~600 m)
• 23 Mbit/s at 3,000 feet (~900 m)
• 22 Mbit/s at 4,000 feet (~1.2 km)
• 21 Mbit/s at 5,000 feet (~1.5 km)
• 19 Mbit/s at 6,000 feet (~1.8 km)
• 16 Mbit/s at 7,000 feet (~2.1 km)
• 8 Mbit/s at 10,000 feet (~3 km)
• 1.5 Mbit/s at 15,000 feet (4.5 km)
• 800 kbit/s at 17,000 feet (~5.2 km)