Broadband 101


Basic Terminology

  • Bits are the base unit of information in computing. Network speeds are usually measured in “bits per second”
  • 1 Kilobit (Kbps) = 1,000 bits transferred per second (bps) Dial-up connections are 56 Kbps
  • 1 Megabit (Mbps) = 1,000,000 bps; about 30 seconds to download an MP3 song
  • 1 Gigabit (Gbps) = 1,000,000,000 bps; about 10 seconds to download an HD movie
  • Bytes are the base unit for file size and used in computing monthly caps
  • FCC Definition for “basic broadband” is 25 Mbps downstream; 3 Mbps upstream; users can perform basic tasks but many argue this definition sets the bar too low (Additional FCC Information)
  • Download” is the speed, measured in bits, that your computer receives data
  • Upload” is the speed that your computer sends data
  • Symmetric” connections are comparable in upload and download speeds. DSL and cable often has upload speeds 5-10x slower than downstream. Businesses increasingly need symmetric connections to maximize productivity

Traditional Technology

  • DSL uses the copper telephone lines to deliver access to the Internet. Common DSL downstream speeds are .5 to 6 Mbps, though they can get up to 40 for people living very close to the equipment that generates the signal. Upstream speeds are often below 1.5 Mbps and rarely exceed 4.
  • Cable, fittingly enough, uses a cable network to deliver services. Speeds commonly vary from 6-30 Mbps download and 1-3 Mbps upload on standard tiers. Some cable companies offer 100 Mbps down and 10 Mbps up for a hefty premium. However, cable networks are shared, meaning you may not achieve the advertised speeds during periods of peak usage due to congestion from your neighbors.
  • Wireless Internet access is a complement to wired connections, not a substitute. Many 4G networks have caps that strictly limit usage.

Common Broadband Goals

  • Faster speeds now
  • Affordable service
  • Reliable performance
  • Universal access
  • Scalable Networks (often fiber-optic) that allow capacity to grow as a rapidly as demand

Fiber Optics

  • The Gold Standard.
  • Basic idea: Lasers shoot pulses of light across very thin strands of glass.
  • Fiber optic networks are reliable, resilient, and use technology that offers nearly unlimited expansion. They have fewer points of failure than copper and cable networks.
  • Fiber strands last for decades and capacity can be increased by upgrading the lasers on each end without having to lay new fiber.
  • The high cost of new fiber networks is mostly the labor to put the cables in place on poles or in conduit underground; operating costs are lower than for cable, DSL, or wireless networks.