Wireless Technologies
Wireless LAN/Wi-Fi
"Wi-Fi" is a trademark of the Wi-Fi Alliance and the brand name for products using the IEEE 802.11 family of standards. It is also known as wireless LAN (WLAN) and can refer to as any of the established 802.11 standards: 802.11a, 802.11b, 802.11g and 802.11n. New wireless standards will continue to evolve.
The wireless technology is fast evolving, and consumer needs to be aware of their PC & router capability and limitation, so as to avoid misunderstanding and mismatch in performance expectation and surfing experience.
A device enabled with Wi-Fi, such as a personal computer, video game console, smart phone, or digital audio player, can connect to the Internet via a wireless router that connects to a modem.
The 802.11 family consists of a series of over-the-air modulation techniques that use the same basic protocol.
| 802.11 Standard | 802.11b | 802.11g | 802.11a | 802.11n | |
|---|---|---|---|---|---|
| Frequency | 2.4GHz | 2.4GHz | 5GHz | 2.4GHz | 5GHz |
| Channel Bonding | No | No | No | Yes | Yes |
| Max Bandwidth Per Channel | 11Mbps | 54Mbps | 54Mbps | 270Mbps | 270Mbps |
| Range (Unblock, LOS) | ~30m | ~30m | - | ~50m | ~30m |
There are factors that can adversely affect the wireless network connection (speed performance, or data throughput rate) and user surfing experience, includes:
- LOS or Line of sight, blockage (walls etc), and distance between PC and routers. 802.11(a/b/g) is unable to pass through a solid object without a significant reduction and dissipation of the signal.
- Compatibility of 802.11 standards between the PC and routers.
- Interference from others wireless devices or WLAN operating at same or interfering frequency range.
- Configuration of the PC and routers.
- Hardware performance of the PC and routers.
- Volume of network traffic.
Data security Risks
As wireless signal may go beyond your home, outsider may be able to access to your wireless LAN if it is not protected (eg. using wireless encryption). Wired Equivalent Privacy (WEP), is the most common wireless encryption-standard, may be more easily breakable even when correctly configured. Wi-Fi Protected Access (WPA and WPA2) encryption, which became available in devices in 2003, aimed to solve this problem.
Dual Band
Dual band refers to the capability to transmit on the 5 GHz band of 802.11a and also the 2.4 GHz band used by 802.11b, 802.11g, and 802.11n. Ordinary Wi-Fi equipment only supports one signal band, whereas dual-band gear contains two different types of wireless radios and can support connections on both 2.4 GHz and 5 GHz links.
Dual-band Wi-Fi is a feature of some wireless routers and network adapters.
Dual Band Routers
Ordinary routers only support one wireless signal band, while dual-band routers can support connections on both 2.4 GHz and 5 GHz links.
Some 802.11n Wi-Fi routers also allow simultaneous dual band communication with both 2.4 GHz and 5 GHz clients at the same time. These routers provide maximum flexibility in setting up a home network. It allows 802.11b/g/n clients to run on the 2.4 GHz side, 802.11a and 802.11n clients can run at 5 GHz.
Dual Band Adapters
Dual-band Wi-Fi network adapters likewise contain two wireless radios. These adapters can be configured to use either 802.11a via one radio, or the 802.11b/g/n family via the other, but not both.
