Wireless LAN is the most prevalent form of communication for devices in a particular region. When wireless LAN is used in practically any type of environment, its vulnerability to threats increases. As a result, understanding these risks and weaknesses is crucial. Unlike wired networks, which need physical access to the equipment, wireless networks can be abused and targeted from afar (Coleman, 2014).
This can occur when an attacker establishes a rogue entry point within an existing LAN. An attacker sets it up to essentially sniff wireless network traffic in order to obtain access to a legitimate network. They offer simple network access and leave the user unaware of their vulnerability for an extended amount of time.
Denial of Service
The attack is done by sending a large amount of traffic at a particular target. These limits access to services. For instance causing of interferences over the 2.4 GHz band, since the band is only limited to only three non-overlapping channels, an attacker needs to cause enough interference to these channels to initiate service interruption.
Threat Minimization
Encryption prevents the attacker's form identifying and decoding the type of information being transmitted over the network. These protect the confidentiality of information sent over the wireless network by encrypting all wireless traffics.
Signal hiding is also an effective way of preventing interception from attackers. With this technique, attackers are unable to identify and locate a wireless network. This can be done by using bidirectional antennas to constraint signal emanations within desired network coverage.
Spread Spectrum Technology
Spread spectrum is an RF communications system where the baseband signal bandwidth is spread over a larger bandwidth by injecting a higher frequency signal. Spread spectrum takes the data to be transmitted and spreads it across the frequencies using it (Coleman, 2014). The two types of spread spectrum modulations are frequency hopping (FHSS) and direct sequencing (DSS).
FHSS spread spectrum; data is transmitted using a small frequency carrier space, then hops to another frequency carrier space and transmits then to another frequency and so on. This implies that data is transmitted at a particular frequency for a given period of time.
In DSSS, spread spectrum carrier stays at the same frequency. The narrowband data is spread over a much larger bandwidth by use of pseudo-random chip sequence. The narrowband signal and spread spectrum signal both use the same amount of transmitting power to carry the same information.
Comparison between FHSS and DSS
Similarities between DSSS and FHSS
In terms of similarities, both DSSS and FHSS can operate without errors with other radio signals in the same band. Besides that for a given level of band interference, both DSS and FHSS have the capability to operate with lower signal level and hence, able to operate over long distances for the same level of transmitted energy.
Differences between DSSS and FHSS
FHSS systems lean on diversifying RF carrier frequency, this result to rough nature of mistakes due to frequency selective fading channel. On the contrary, in DSSS, info bits are distributed across both frequency and time planes minimizing interference and fading effects. This implies that DSSS systems are prone to gross blunders but at low levels compared to FHSS.
Importance of the Spread Spectrum
Low Power Density
The amount of energy per specific frequency transmitted is very low. The result of low power density transmitted signal is that such a signal will not interfere with other systems trans-receivers in the same location.
Resistance to Interference and Jamming Effect
Spread spectrum systems present a high resistance to noises and interference. This makes it possible to recover their original information even on a noisy medium. Interference and jamming signal are rejected since they do not have the spread spectrum key.
Reference
Coleman, D. D. (2014). Certified wireless network administartor. Indiana: Wiley.
