When purchasing as router for use with a wide-area, keep in mind that wide-area networking spans many different devices and services. Interface considerations will vary depending upon the type of service and the kinds and amount of traffic that will be sent over it.
Protocols are agreed upon formats for translating data between devices. Protocols determine many different aspects of the data including, error checking, compression types as well as indications of delivery and retrieval by devices. There are a variety of standard protocols from which programmers can choose. Each with its particular advantages and disadvantages; meaning that, some are simpler than others, some are more reliable, and some are faster. For the user, it is important that the device have the correct protocols in order to be able to communicate with other computers.
Firewall / VPN
Stateful Packet Inspection (SPI), DoS Prevention, MAC Address Filtering, IP Filtering, NAT
Internal antennas are built into the device and can not be changed or directed. External antennas can be directed to point in different directions; this may be used to increase range of the device. Detachable antennas are screwed into the device and can be upgraded or replaced easily.
There are many standards of modulation. The following are some of the most commonly used types.
DSSS DSSS (Direct-Sequence Spread Spectrum) is a transmission technology that combines the data signal with a higher data rate bit sequence called a chipping code. This improves noise resistance and data integrity.
OFDM OFDM (Orthogonal Frequency Division Multiplexing) transmits digital data over a radio wave by splitting a radio signal into multiple sub-signals. These are then transmitted simultaneously at different frequencies. This modulation technique reduces the amount of crosstalk in signal transmissions.
CCK CCK (Complementary Code Keying) uses a set of 64 eight-bit code words to encode data for 5.5 and 11Mbps data rates in the 2.4GHz band of 802.11b standard. The code words have unique mathematical properties. This allows them to be correctly distinguished from one another by a receiver even in the presence of substantial noise and interference.
WEP data encryption is defined by the 802.11 standard to provide two main security features to a network. The first is to prevent access to the network by "intruders" using similar wireless LAN equipment. The second is to prevent eavesdropping of wireless LAN traffic. WEP works by allowing an administrator to set defined respective 'keys' for each wireless network. Access is denied by anyone who does not have a key.
The wireless standards that are supported by the device, these standards tell you which functionalities a device has as well as the standards that should be supported by the wireless adapter itself.