Overview of Wireless Technologies
As mentioned above wireless technologies, in the simplest sense, enable one or more devices to communicate without physical connections—without requiring network or peripheral cabling. Wireless technologies use radio frequency transmissions as the means for transmitting data, whereas wired technologies use cables. Wireless technologies range from complex systems, such as Wireless Local Area Networks (WLAN) and mobile phones including the new generation of 3G mobile phones, to simple devices such as wireless headphones, microphones, and other devices that do not process or store information. They also include Infrared (IR) devices such as remote controls, some cordless computer keyboards and mice, and wireless hi-fi stereo headsets, all of which require a direct line of sight between the transmitter and the receiver to close the link.
Wireless networks serve as the transport mechanism between devices and among devices and the traditional wired networks (enterprise networks and the Internet). Wireless networks are many and diverse but are frequently categorized into five groups based on their coverage range: Wireless Wide Area Networks (WWAN); Wireless Metropolitan Area Network (WMAN); Wireless Local Area Network (WLANs), Mobile Broadband Wireless Access (MBWA), and Wireless Personal Area Networks (WPAN). WWAN includes wide coverage area technologies such as 2G cellular, Cellular Digital Packet Data (CDPD), Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS) and Mobitex. WMAN and MBWA represents wireless internet connection at broadband speeds within city or suburbs, it includes 802.16 and emerging standards such as 802.20. WLAN, representing wireless local area networks, includes 802.11, HiperLAN, and several others. WPAN, represents wireless personal area network technologies such as Bluetooth and IR.
Wireless Technologies and Standards
There are a number of standards used in wireless technologies. Some of the key ones include:
- The IEEE 802.11 standards provide specifications for high-speed networks that support most of today’s applications. The IEEE 802.11 specifications are wireless standards that specify an "over-the-air" interface between a wireless client and a base station or access point, as well as among wireless clients. These 802.11 standards can be compared to the IEEE 802.3 standard for Ethernet for wired LANs. The IEEE 802.11 specifications address both the Physical (PHY) and Media Access Control (MAC) layers and are tailored to resolve compatibility issues between manufacturers of Wireless LAN equipment.
- IEEE802.15 provides standards for low complexity and low-power consumption connectivity.
- IEEE 802.16 standard, the “Air Interface for Fixed Broadband Wireless Access Systems” is also known as the IEEE WirelessMAN air interface. This technology is designed to provide wireless last-mile broadband access in the Metropolitan Area Network (MAN), delivering performance comparable to traditional cable, DSL, or T1 offerings.
- Bluetooth (Wireless Personal Area Network) is an alternative wireless network technology that has followed a different development path than the 802.11 family. Bluetooth supports a very short range (approximately 10 metres) and relatively low bandwidth (1 Mbps). In practice, Bluetooth networks PDAs or cell phones with PCs but does not offer much value for general-purpose WLAN networking. The Bluetooth standard was developed by a computer and communications industry consortium, specifying how mobile phones, computers, and PDAs interconnect with each other, with home and business phones, and with computers using short-range wireless connections.
- IEEE 802.1X offers an effective framework for authenticating and controlling user traffic to a protected network, as well as dynamically varying encryption keys. 802.1X ties a protocol called EAP (Extensible Authentication Protocol) to both the wired and wireless LAN media and supports multiple authentication methods, such as token cards, Kerberos, one-time passwords, certificates, and public key authentication.
This list of standards is in no way comprehensive. This paper does not go into the detail of each of the standards within the IEEE 802.11 family but in general terms stipulates the concerns/risks/vulnerabilities within this group of standards and some ways to manage them. There are several standards within IEEE 802.11 ranging from IEEE 802.11a to IEEE 802.11R. There are also emerging standards including IEEE 802.11j, 802.11k, 802.11m and 802.20.
It is also important to note that this paper does not focus on other WLAN standards besides IEEE 802.11 such as the European Telecommunications Standards Institute’s (ETSI) HiperLan and the
Security Features of IEEE 802.11
The IEEE 802.11 WLAN – or WiFi specification has identified several services to provide a secure operating environment. The security services are provided largely by the Wired Equivalent Privacy (WEP) protocol to protect link level data during wireless transmission between clients and access points. WEP does not provide end-to-end security, but only for the wireless portion of the connection. However, there are a number of problems with the WEP protocol and its vulnerabilities significantly limit its ability to safeguard data. Commonly available tools such as AirSnort, WEPCrack and dweputils have the ability to crack WEP keys by analysing traffic from totally passive data captures. An improvement on WEP is the Wi-Fi Protected Access (WPA) which was introduced in 2003. WPA avoids most of WEP's vulnerabilities and WPA-PSK is the current minimum standard and WPA2 (Advanced Encryption Standard (AES) with RADIUSauthentication), is industry best practice.
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