A computer network is an interconnection of computers and other devices in a particular manner for the purpose of sharing resources. The resources being shared in a network could either be software like files and applications or hardware like printers and scanners. The interconnection of these devices in a Local Area Network (LAN) are traditionally achieved using cables (a wired connection) terminated on the Network Interface Cards (NIC) on these devices or without cables (a wireless connection). Wireless networks (WLANs) as specified by the IEEE 802.11 standard uses free space as the medium of communication between two devices.
In carrying out this research, a number of resources have been obtained as sources of information for the work. These are reviewed as follows.
In a paper from U.S. Robotics, a general overview of the WLAN technology with emphasis on the different IEEE 802.11 specifications, the signaling techniques, WLAN performance and security issues was provided. This paper will be useful in providing a general knowledge base as an entry point to gaining better understanding of the whole WLAN technologies.
In Malladi and Agrawal (2002), information on the applications of mobile and wireless network technologies are presented. This paper will be useful to source information on the different applications that WLANs can be used for.
The security issues in WLANs will be examined using the work of Lackner (2013) who did a comparative study on the security issues in wireless network standards; and the work of Goel et al. (2013) where the different techniques of securing a wireless network using authentication is examined.
Components of a WLAN
The basic components of a WLAN include a wireless NIC card or PCI Adapter for desktop computers, an Access Point (AP) and a wireless router. The NIC card is a hardware component of a PC that allows the transmission and reception of radio signals. The AP is the link or bridge between the wired part of a network and the wireless part of the network. The wireless router enables multiple devices to share the same connection.
The IEEE 802.11 Standard
The physical layer and the Media Access Control (MAC) layers of the WLAN are specified in the IEEE 802.11 protocol with communication achieved over the 2.4 GHz and 5.0 GHz frequency bands. There are different specifications of the IEEE 802.11 wireless standard owing to difference in characteristics such as data rates, range of coverage, frequency of transmission etc. Some of these specifications are presented in table 1.
WLAN Signaling
Since the signals in wireless network communication are transmitted in free space, there is a very high likelihood that the signals will interfere with each other. To prevent this, different signaling techniques are used such as;
Direct Sequence Spread Spectrum (DSSS): transmitted data is spread over a large range of frequencies in the full bandwidth of the frequency band using an encoding scheme.
Frequency Hopping Spread Spectrum (FHSS): where a carrier signal hopping from one frequency to the other is used to transmit data.
Orthogonal Frequency Division Multiplex (OFDM): data is encoded on multiple carrier frequencies with a higher bandwidth obtained.
Security in WLAN
WLAN technology is also susceptible to security breaches especially owing to the broadcast nature of the signals. The effects of wireless network security breaches include identity theft, theft of sensitive information, data loss and denial of service. A number of measures can however be put in place to secure a WLAN such as using authentication and cryptography.
Applications
The applications of WLANs are unlimited as they find relevance in every sphere of business endeavour. Used widely in commerce especially POS terminals of retailers, warehouse inventory management, healthcare, hospitality to enhance the operations of these businesses.
REFERENCES
Goel, S., Behniwal, M. and Sharma, A.J. (2013). Authentication and Key Distribution Schemes for Wireless Sensors Network. International Journal of Advanced Research in Computer Science and Software Engineering, 3(7), 1343 - 1350.
Lackner, G. (2013). A Comparison of Security in Wireless Network Standards with a Focus on Bluetooth, Wi-Fi and WiMax. International Journal of Network Security, 15(6), 420 - 436.
Malladi, R. and Agrawal, P.D. (2002). Current and Future Applications of Mobile and Wireless Networks. Communications of the ACM, 45(10), Pp 144 - 146.
U.S. Robotics. (n.d). Wireless LAN Networking White Paper. PDF. Retrieved from http://support.usr.com/download/whitepapers/wireless-wp.pdf
