What Limits Wireless Bandwidth?by David Dunning
Wireless bandwidth refers to the speed of data transfer between electronic devices capable of communicating wirelessly, using radio-frequency signals. Wireless bandwidth is typically measured in thousands of bits (kilobits) or millions of bits (megabits) per second (Mbps), but numerous factors can limit, or reduce, bandwidth so that wireless connections become slower and less reliable than users might expect.
Wireless bandwidth is limited to the maximum bandwidth specified for any particular wireless technology. Devices that comply with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards -- colloquially known as "Wi-Fi" devices -- offer maximum theoretical bandwidths ranging from 11 Mbps (for 802.11b or wireless-B devices) to 450 Mbps (for 802.11n or wireless-N devices). Bluetooth technology, on the other hand, offers a maximum theoretical bandwidth of 2.1 Mbps (for Bluetooth 2.0 devices).
The strength of wireless signals decreases with distance, so wireless technologies also specify a maximum theoretical range outside of which devices may suffer from reduced bandwidth or receive no wireless signal at all. Wireless-N devices have a theoretical maximum range of 650 feet or more, while Bluetooth 2.0 devices have a theoretical maximum range of about 300 feet, but a device known as a wireless repeater, positioned halfway between wireless devices, can extend these maximum ranges.
Wireless networking signals have relatively high frequencies and short wavelengths, which means they are attenuated, or weakened, by obstructions such as walls, ceilings and metal objects. The weakening of the signal can limit bandwidth, reducing the connection speed to a crawl or making it difficult for wireless devices to establish a connection in the first place. Large, substantial obstructions in close proximity to wireless devices cause the most interference to wireless signals.
Other factors, including radio interference from common household devices, such as cordless phones, microwave ovens and remote-control toys, or terrain, vegetation and even weather conditions, such as high air pressure, rain and wind, can limit bandwidth. Some wireless devices, known as dual-band devices, can operate in the 2.4 GHz and the less crowded 5 GHz frequency band of the radio spectrum, so switching to the higher frequency can reduce interference and its effects on bandwidth. Otherwise, you can reduce radio interference by choosing household devices that operate in a different frequency band, such as the 900 MHz band, from your wireless networking devices.