Wi-Fi® – Is a certification mark developed by the Wi-Fi Alliance to indicate that wireless local area network (WLAN) products are based on the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11 standards.
But the Wi-Fi® 802.11 network standard comes in many flavors – 802.11a, 802.11b, 802.11g, and 801.11n. The key difference is the maximum speed at which data can be transmitted under optimal conditions as well as the frequency of the radio waves, 2.4Ghz or 5Ghz.
Most Wi-Fi® Routers (acts as a gateway and translates one external Internet IP address to many private internal IP addresses for each Wi-Fi® device) and Access Points (acts as a bridge and adds wireless Wi-Fi® capability to a wired network) are 100% backward compatible. They support the highest speed of 802.11n which operates at up to 150Mbit/s, to 802.11g (54Mbits/s) down to the slowest speed 802.11b (11Mbits/s) and operate at 2.4Ghz. Almost every modern Wi-Fi® certified device, such a Smartphones, Blu-Ray players, Internet Enabled TV’s, Tablet Computers, and Internet Radio’s support at least 802.11g with the newest devices supporting the current standard of 802.11n.
When shopping for a Wi-Fi® Router or Access point, look for the 802.11n standard. When reviewing the number of products available, you may see those that claim greater than the standard indoor range of up to 230 feet. The manufacturers are able to accomplish this by using a technology called MIMO (pronounced my-moh) which stands for “multiple input and multiple output.” In simple terms, the manufacturers add more antennas to transmit and receive the wireless data signal. This improves the efficiency and reliability of the Wi-Fi® data signal between the Router/Access Point and the Wi-Fi® enabled device.
Within reason, the claims of greater distance and better coverage are accurate. A Router/Access Point that has three antennas is better than one with two antennas. More antennas mean better coverage and range.
802.11a supports up to 54Mbit/s like 802.11g but offers the advantage of operating in the 5Ghz frequency range which is significantly less crowded than the 2.4Ghz range. The 2.4Ghz frequency is used by a number of devices including microwave ovens, baby monitors, cordless phones, remote controls, TV’s, Blu-Ray Players, Notebooks Computers, and is the most popular hence the crowding.
Although less crowded, the one disadvantage of 802.11a is that the higher frequency 5Ghz signal uses a shorter wavelength which is more easily absorbed by walls and other solid objects. 802.11a works best in wide open areas with line of sight between the Router/Access Point and the device you want to connect.
Some manufacturers offer the best of both worlds: Wi-Fi® Routers and Access Points that support both 802.11a and 802.11n/g/b operating simultaneously on both the 5Ghz and 2.4Ghz frequencies. The Router/Access Point creates two separate Wi-Fi® networks: one at each frequency. The particular device you are trying to connect will figure out which frequency/ Wi-Fi® network it supports and use the best signal available to the Router or Access Point.
Note: It seems contradictory but in some cases Wi-Fi® operating at the 802.11b standard of 11Mbits/s with the ability to drop down to 5Mbits/s or even 1Mbits/s may have a greater effective range than the longer range 802.11g at 54Mbits/s. This is because the slower speeds are subject to less interference.
Less expensive Routers and Access Points may only support the 802.11b/g standards but provide a value priced alternative. They also offer the greatest level of compatibility for both old and new Wi-Fi® devices. If you have devices that support 802.11n, then make sure to purchase a Router or Access Point that supports 802.11n to get the maximum benefit of the newer standard.
In short, the more expensive the Router or Access Point, the better the feature set and the more configuration options available for the best possible Wi-Fi® experience.