Wireless Personal Area Network Wpan Computer Science Essay

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Wireless networking is becoming more preferable than wired networks by users all around the world. This paper demonstrates a brief explanation about few kinds of wireless networks, such as: Wireless Local Area Networks sometimes referred to as Wi-Fi, WiMax and Wireless Personal Area Network (WPAN) which is provided by using the Bluetooth technology. The main issue covered in the report is the security challenges regarding Wi-Fi, and it proves that by implementing specific security standards such as: Wi-Fi Protected Access (WPA) in the Data Link layer more security would be provided to the wireless network than by just depending on the standard security protocol in the network layer (IPSec). The paper concludes that the Data Link layer security is a more reliable, compelling solution and that network layer security improves link layer security and not replaces it.


A wireless network is any network of computers and computer peripherals that communicate with each other without using wires. The devices in this type of networks broadcast their packets using radio waves or optical wavelengths. Almost all wireless networks in the world work on a standard set up set by the Institute of Electrical and Electronics Engineers known as the 802.11 standard. Users can benefit from wireless networks whether it is set up at home, a small business or even a huge enterprise. For instance, a user can access the network resources from any location within his/ her wireless network's coverage area. Using a wireless network, the user is no longer tied to his/ her desk as he/ she was with a wired connection. Furthermore, a wireless network is easy to setup because there are no cables to be stringed, thus the installation can be quick and cost-effective. Not forgetting to mention that a user can easily expand wireless networks with existing equipment, unlike the wired network where additional wiring might be required. Wireless networks' types vary depending on the geographical area covered and the technology of transmission being used.

Types of Wireless Networks:

Wireless Personal Area Network (WPAN):

These types of wireless networks allow the transmission of data between devices within a reasonably small area, generally within reach of a person. WPANs can be implemented using the Bluetooth technology which transmits data via low-power radio waves. The radio technology used by Bluetooth is called frequency-hopping spread spectrum. This technology chops up the data being sent and transmits chunks of it in the range 2.402 GHz - 2.480 GHz (gigahertz). Bluetooth is a packet-based protocol with a master-slave structure where one master may communicate with up to seven slaves in a WPAN, or a piconet; all devices share the master's clock. Three versions of Bluetooth standards have been used up till today. The Bluetooth 1.2 version supports a data rate of 1 megabit per second (Mbps), while Bluetooth 2.0 can manage up to 3 Mbps. The latest Bluetooth 3.0 version can manage up to 24 Mbps. Bluetooth exists in various devices nowadays, such as the cell phones, laptops, video games such as Wii and other computer peripherals. A user can simply send data from his/ her laptop to his/ her cell phone using the Bluetooth technology.

Wireless Local Area Network (WLAN):

A WLAN is usually referred to as a Wi-Fi (Wireless Fidelity) network or 802.11 network. This type of wireless network covers a limited geographical area, such as: a house, an airport, a coffee shop (30-100 meter or 100-300 feet). Any place that allows users to connect wirelessly is called a wireless hotspot. A simple Wi-Fi network consists of two or more computers each equipped with Wi-Fi network cards (wireless clients) and a wireless router (access point) and it usually operates at a radio frequency of 2.4 GHz or 5 GHz. When the wireless client sends out the data, the binary data will be encoded to radio frequency and transmitted via wireless router. The receiving wireless client will then decode the signal back to binary data.

IEEE 802.11 standards:

The IEEE 802.11 standards that are common in a Wi-Fi network's hardware are: 802.11a, 802.11b, 802.11g and 802.11n. 802.11a uses orthogonal frequency-division multiplexing (OFDM), an efficient coding technique that splits that radio signal into several sub-signals before they reach a receiver which results in reducing interference. It transmits at a radio frequency of 5 GHz and can handle up to 54 Mbps. Two of the main flaws of this standard are its short range coverage (60-100 feet) and its limited ability to penetrate physical barriers. On the other hand, 802.11b standard which uses complementary code keying (CCK) modulation to improve speeds is more able to penetrate physical barriers and has the longest range coverage (70-150 feet). It transmits at a radio frequency of 2.4 GHz and can handle up to 11 Mbps. Not forgetting to mention that it does not support as many simultaneous connections as 802.11a and it is more susceptible to interference than 802.11a. It is considered the slowest and cheapest standard among all of the standards. Although 802.11g transmits at 2.4 GHz like 802.11b, it is much faster. It can move up to 54 Mbps and its range is between (65-120 feet). The reason behind that is that the 80211g standard uses the OFDM coding used in 802.11a. The latest IEEE802.11 standard for Wi-Fi networks is the 802.11n. The popularity of this new standard is due to its improvement in terms of speed and range. For example, because of network congestion, 802.11g fails to move 54 Mbps as it is supposed to, and only handles about 24 Mbps. Whereas, 802.11n can reach speeds up to 140 Mbps and may offer larger ranges.

IEEE 802.11 Operating modes:

There are two operating modes regarding the wireless network and these are specified by the IEEE 802.11 standards. The modes are:

Infrastructure mode:

Basic Service Set (BSS): enables the connection between wireless clients and an existing wired network with the help from a single access point (wireless router).

Extended Service Set (ESS): is basically two or more Basic Service Sets forming a single subnet.

Ad-hoc mode: This operating mode is also known as peer-to-peer and it is considered as an independent Basic Service Set. It enables a direct connection between wireless clients, without the need for an access point. An ad hoc network consists of up to 9 wireless clients and is useful for quick and easy wireless networks.

Worldwide Interoperability for Microwave Access (WiMax):

This type of wireless network is mainly designed for wireless metropolitan area networks. In other words, it can provide broadband wireless access (BWA) up to 50 km (30 miles) for fixed stations and 5-15 km (3-10 miles) for mobile stations. WiMax is also referred to as IEEE 802.16 network and it is promoted by the WiMax Forum. Although WiMax and Wi-Fi share some essential technical characteristics, each has its own unique perspective of approaching the wireless space. For instance, the IEEE 802.11 WLAN standards describe only four radio link interfaces that operate in the 2.4 GHz or 5 GHz unlicensed radio bands. However, the WiMax standards include a much wider range of potential implementations to address the requirements of carriers around the world. For example, the 802.16a standard that was released in 2003 describes systems operating between 2 GHz and 11 GHz.