Wireless Networking Basics Wireless networking allows you to establish: Communication using standard network protocols and use radio frequency Communication without the use of cables Technologies used for wireless access based on Wireless fidelity (Wi-Fi) Home Radio Frequency (HomeRF)
Types of Wireless Network – I• Peer-to-Peer(P2P) or Ad-Hoc – Connected wirelessly with the use of wireless Network Interface Card (NIC) – Computers can access printers and share files – Wired LAN can be accessed using bridging
Types of Wireless Network – II • Access point or Infrastructure wireless LAN – Wireless device connects to the access point to connect to the network – Access point acts as a hub to connect two wireless devices – Wireless bridge used to connect wireless network to wired network
Wireless Standards• Variety of standards accepted worldwide and offer different levels of security Wireless Standards IEEE 802.11 Bluetooth IrDA HomeRF WiMAX
IEEE 802.11 – I• Developed by Institute of Electrical and Electronic Engineers (IEEE) for defining different aspects of Radio Frequency Wireless networking IEEE 802.11 Standards 802.11 802.11a 802.11b 802.11g 802.11n
IEEE 802.11 – IIStandard Data Max Frequency Compatibility Rate range 802.11 2Mbps 46 2.4 GHz 802.11 meter802.11a 54Mbps 46 5 GHz 802.11a meter802.11b 11Mbps 91 2.4 GHz 802.11b meter802.11g 54Mbps 91 2.4 GHz 802.11b, meter 802.11g802.11n 540 2.4/5 GHz Mbps
IEEE 802.11 – III• Security – Four methods of wireless network security: • Data encryption (WEP and WPA) • Port based access control • Service Set Identifier (SSID) • Media Access Control (MAC) address filtering
Security - I• WEP – suitable for small network – Uses 64/128 encryption algorithm – Encryption key is static and shared – No mechanism for user authentication WPA – uses dynamic encryption key user authentication through Extensible Authentication Protocol (EAP) SSID – is a 32 character unique identifier inserted into header of each packet to secure your network configure your AP with unique SSID name
Security - II• MAC address filtering – preferred for smaller network – MAC address listed in the list can access other devices in the network – If any NIC is failed then you have to reconfigure the AP Port Based Access control (802.1x) – uses EAP hardware used such as supplicant, authenticator, and authenticating server must be 802.1x enabled to use the network
Components Requirements• The important components required for setting up a wireless network are: – Medium – Access point and Extension point – Wireless bridges and Power line bridges – Antennas – Wireless adapters – Wireless Station and Server – Software
Medium• Wireless medium is an unguided form of networking medium• Wireless transmission involves use of technologies such as Bluetooth, Infrared, Lasers, Radio signals and Microwave technologies• Lasers, infrared and Bluetooth are used mainly in LAN environment whereas microwave and other radio frequencies are used to connect vast geographical locations• Mobile computing allows users to do their work at any location
Access Point and Extension Point• Access Point – Device that bridges a wireless connection and a wired connection – Two types of access points: Hardware access points and Software access points – Generally acts as a hub and operates at layer 1• Extension Point – Used if single access point is not able to cover entire area – Acts as wireless relay extending the range of wireless network
Hardware Access Points• Hardware access point is a physical device that is used to establish a connection between a wired network and a wireless network
Software Access Points• Software Access Points are computer which includes a wireless network interface card.
Extension Point• Extension points are used if a single access point is not able to cover the entire area.
Wireless and Power-line bridges• Wireless bridge Power-line bridge – Used to connect two or Used to penetrate a more wireless networks wireless network that is otherwise difficult to penetrate
Antennas and Adapters• Antennas are used to increase the range of wireless network• Antennas should be compatible with the router, AP or the adapter i.e. installed in the network• Types of antennas used: – Omnidirectional antennas - Used indoors and small in size – Directional antennas - High gain and used for long range outdoor use• Wireless adapters help to connect computer or PDA to a network• Wireless adapters are available as PC cards, PCI and mini PCI, USB, and CompactFlash.
Wireless Station and Server• Wireless Local Area Network consists of wireless station and wireless server• Wireless station - Connects wireless network into a wireless medium Wireless Stations Wireless Clients Access Points Wireless server – The main server connected to the wired network which controls all devices within the wireless network
Software• Wireless network adapter requires two types of software so as to function properly: – Driver – Configuration Utility• Windows XP has built-in tools for configuring network adapter settings• It is better to use the drivers and configuration utilities provided by the vendor along with the wireless adapter
Application• Common applications of wireless technologies: – Wireless Local Area Network (WLAN) – Wireless Wide Area Network (WWAN) – Wireless Personal Area Network (WPAN) – Wireless Metropolitan Area Network (WMAN) – Mobile Computing
Problem Solving• Wire and Wireless Adapter – Software Troubleshooting - Wireless adapter configuration utility and wireless AP’s firmware version• Driver Compatibility• Low signal strength – Can be solved with: – Interference – Installing repeater – Changing Antenna – Installing Window XP Service Pack 2
Problem Solving• Network settings – Common network setting problems are: – SSID setting – DHCP Addresses – Encryption Keys – MAC Address Filters