5GHz WiFi Disadvantages
Disadvantages - Shorter Range, Cost, Old Component Replacement
There are some disadvantages to going to a 5GHz wireless network. One is that the higher the frequency of a wireless signal, the shorter its range. For example, 2.4 GHz networks cover a substantially larger range than 5 GHz wireless networks. 5 GHz networks do not penetrate solid objects such as walls nearly as well as do 2.4 GHz signals. This can limit an access points reach inside buildings like homes and offices where many walls may come between a wireless antenna and the user.
Another disadvantage is that 5GHz equipment does not readily mix with 2.4GHz equipment already installed. This is a consideration if you're upgrading a current large wireless network installation. If you wanted to mix an already installed 2.4GHz network with a 5GHz network, you would have to make sure all components of the network is dual band.
Cost is another factor. The popularity of 2.4GHz means that wireless network components such as access points, antennas and network cards are more easily available and costs less.
One perceived advantage of a higher frequency is speed. However, 5GHz networks are not necessarily faster than 2.4GHz. There are 2.4GHz products using 802.11g that can match or can be faster that 5GHz 802.11a by using paired radios inside access points instead of one which can increase capacity up to 108Mbps.
As you can probably see, switching to 5GHz requires planning. There are a few things to consider before making the jump. In general, if high performance and over crowding of other 2.4GHz networks in the area is an important factor, then 5GHz wireless network may be the answer. However, If you have little control of what network cards your users are using or of access points, then a 2.4GHz system may be a better choice.
Have It Both Ways - Dual Band Wireless Networking
Unless you control and limit the devices used on your network, a dual band network works best. If, on your network, you have 5GHz equipmnet AND anyone might use devices like iPads, iPods, WiFi enabled smart phones and other devices that can only use 2.4GHz, dual band routers will be required. Dual band equipment that covers both 2.4GHz and 5GHz is ideal and covers the best of both worlds. If the cost is within your budget, a dual band wireless network should be considered.