Your first decision revolves around standards: 802.11a, 802.11b or 802.11g. The market for 802.11a-only APs is limited, primarily because 802.11b is so firmly entrenched. However, if you are designing a network that requires high performance and you want to prevent the masses from accessing your network, 11a may be the way to go, but just be aware that you'll need to purchase 11a NICs for your client devices. Although 11a products support higher data rates than 11b (54 Mbps for 11a versus 11 Mbps for 11b), they tend to be more expensive and have shorter range. The range limitations are such that it may be impossible to provide full coverage in a branch or home office with 11a using a single AP, and the FCC's tighter regulations on 5-GHz products usually makes it impossible to use high-gain antennas to extend range.
View our Interactive Buyer's Guide on WAP and Gateways
The 802.11g standard combines the OFDM (orthogonal frequency division multiplexing) signal encoding technology of 11a with the 2.4-GHz frequency of 11b. In addition, 11g promises backward compatibility with 11b--but the cost of coexistence is reduced performance. In many instances, performance for all devices drops to the level of the slowest device.