Wireless Network Speeds

Question: How Fast Is a Wi-Fi Network?

Theoretical vs. Actual Network Speeds

Like most kinds of computer networks, Wi-Fi supports varying levels of performance depending on which technology standards it supports. Each Wi-Fi standard is rated according to its maximum theoretical network bandwidth:

• 802.11b offered up to 11 megabits per second (Mbps)
• 802.11a and 802.11g offer up to 54 Mbps
• 802.11n offers up to 300 Mbps

The performance of Wi-Fi networks practically never approaches these theoretical maximums. 802.11b networks, for example, generally operate no faster than about 50% of theoretical peak, around 5.5 Mbps. Likewise, 802.11a and 802.11g networks generally run no faster than 20 Mbps. And even though 802.11n rates at 300 Mbps compared to wired Fast Ethernet at 100 Mbps, the Ethernet connection can often outperform 802.11n Wi-Fi in real-world usage.

Factors Limiting Wi-Fi Connection Speeds

The disparity between theoretical and practical Wi-Fi performance comes from network protocol overhead, radio interference, physical obstructions on the line of sight between devices, and decreasing signal strength with distance. In addition, as more devices communicate on the network simultaneously, its performance will also decrease. A Wi-Fi network connection operates at the highest possible speed that both devices (endpoints) can support. An 802.11g laptop connected to an 802.11n router, for example, will network at the lower speeds of 'g'.
On home networks, the performance of an Internet connection is often the limiting factor in end-to-end network speed. Even though most residential networks support sharing files within the home at speeds of 20 Mbps or more, Wi-Fi clients will still connect to the Internet at the usually lower speeds supported by Internet providers.
Wi-Fi performance continues to be improved with future generations of the technology. Speeds upwards of 1 Gbps (1000 Mbps) are expected with next-generation 802.11ac Wi-Fi.

Suggested Reading

• How Can I Achieve an 802.11n Speed Rating of 300 Mbps?
• How Fast Is 802.11g Wi-Fi Networking?
• What Is the Actual Speed of an 802.11b Wi-Fi Network?
  
  
  courtesy: About.com