narrowband noise and simple jamming. Both transmitter and receiver must
have their hopping sequences synchronized to create the effect of a single
"logical channel". To an unsynchronised receivers an FHSS transmission
appears to be short-duration impulse noise. 802.11 may use FHSS or DSSS.
6. Do I need the same kind of antenna on both sides of a link ?
No. Provided the antenna is optimally designed for 2.4GHz or 5GHz operation.
WLAN NICs often include an internal antenna which may provide sufficient
reception.
7. Why the 2.4 Ghz Frequency range ?
This frequency range has been set aside by the FCC, and is generally labeled
the ISM band. A few years ago Apple and several other large corporations
requested that the FCC allow the development of wireless networks within this
frequency range. What we have today is a protocol and system that allows for
unlicensed use of radios within a prescribed power level. The ISM band is
populated by Industrial, Scientific and Medical devices that are all low power
devices, but can interfere with each other.
8. What is Server Set ID (SSID) ?
SSID is a configurable identification that allows clients to communicate to the
appropriate base station. With proper configuration, only clients that are
configured with the same SSID can communicate with base stations having the
same SSID. SSID from a security point of view acts as a simple single shared
password between base stations and clients.
9. What is an ESSID ?
ESSID stands for Extended Service Set Identifier and identifies the wireless
LAN. The ESSID of the mobile device must match the ESSID of the AP to
communicate with the AP. The ESSID is a 32-character maximum string and is
case-sensitive.
Security FAQ
1. How do I secure the data across an Access Point's radio link ?
Enable Wired Equivalency Protocol (WEP) to encrypt the payload of packets
