Chapter 1: Wireless Networking/Technology

1. Chapter 1:Wireless Networking/Technology

2. Wireless Networking • Definition: • the technologies that enable computers to communicate using standard network protocols broadcasted on a radio frequency rather than on cable. • Nowadays has grown with various products and very popular with homes, businesses and schools, and handheld equipment.

3. Wireless Networking

4. Wireless Networking • Two kinds of wireless networks: • ad-hoc or peer-to-peer networking • infrastructure networking

5. Ad-hoc or peer-to-peer networking • Consists of a number of computers that each equipped with wireless networking interface card (figure 1). • Each computer can communicate directly with the other entire wireless enabled computer but may not be able to access wired resources. • Fixable if one of the computers acts as a bridge to the wired LAN using special software and/or additional hardware to connect to the wired LAN.

6. Figure 1: Wireless Network IC

7. Ad-hoc or peer-to-peer networking

8. Infrastructure networking • A wireless network can also use an access point, or base station. • Two types of access point: • dedicated hardware • integrated • The access point acts like a hub, providing connectivity for the wireless computers. • Can connect the wireless LAN to a wired LAN, allowing wireless computer access to LAN resources, such as file servers or existing internet connectivity.

9. Dedicated Hardware Access Point (HAP) • Usually used as an extension of a wired network, providing additional access in remote areas or for a mobile workforce.

10. Figure 2: 2:Dedicated hardware access point

11. Integrated Access Points • Multi functional devices which include features not commonly found in access points, such as integrated PPPoE support and extensive configuration flexibility. • Provide both wired and wireless access in one unit. • With appropriate networking support, users on the wireless LAN can share files and printers located on the wired LAN and vice versa. • All current configurations provide total support of the TCP/IP

12. Figure 3: Integrated access point

13. Infrastructure networking • There could be many networked computers using a single access point. • Some hardware access points limit to 10. • Newer models will support up to 225 wireless connections. • It is a shared media, using more computers than recommended will cause performance and reliability to suffer.

14. Infrastructure networking • For large networks, designers could have / use more than one access points to connect to a wired LAN, or even to a second wireless LAN if the access point supports this. • In most cases, separate access points are interconnected via a wired LAN, providing wireless connectivity in specific areas such as offices or classrooms, but connected to a main wired LAN for access to network resources, such as file servers (figure 4).

15. Figure 4: Large network with multiple access points

16. Infrastructure networking • When using multiple access points, each access point wireless area should overlap its neighbors. This provides a seamless area for users to move around in using a feature called roaming. • Roaming: • the extending of connectivity service in a network that is different than the network with which a station is registered.

17. Infrastructure networking • A wireless computer can “roam” from one access point to another, with the software and hardware maintaining a steady network connection by monitoring the signal strength from in-range access points and locking on to the one with the best quality (figure 5).

18. Figure 5: Roaming

19. Wireless network interconnects two or more LANs Ohhs…. It is too difficult to install fiber for networking the schools, campuses… “ahh.. Wireless networking…”

20. Wireless LAN • Need to bridge to create WLAN. • There are two types of bridging: • point-to-point • point-to-multipoint • WLAN bridging connections can be significantly less costly and a much faster installation compared to time consuming permit process and trenching needed for installing fiber.

21. Wireless LAN • IEEE 802.11 (Wireless LAN) standard has various versions. • IEEE 802.11: • a standard produced by the Institute of Electrical and Electronic Engineers (IEEE). • define all aspects of Radio Frequency Wireless. • Series  802.11b, 802.11a, 802.11g, 802.11n. • Not all 802.11 networks are compatible • Wi-Fi Certified (Wi-Fi.org).

22. Wireless LAN • Antennas are often used to increase the range of WLAN systems, but proper antenna selection can also enhance the security of WLAN. • Using a directional antenna will decrease the chances of signal interception. • Some bridges support repeater mode.

23. Figure 6: Point to Point

24. Figure 7: Point to Multipoint

25. Figure 8: Repeater Mode

26. Wireless Technology Bluetooth

27. Bluetooth Technology • Is an open specification for short-range wireless communication between electronic devices. • Has become a standard for interconnecting small mobile devices in wireless world. • Its specification is developed, published and promoted by Bluetooth Special Interest Group (SIG).

28. Bluetooth Technology • Used for Wireless Personal Area Networks (WPANs) with range around 10 m. • it is a low-power short-range radio communication technology. • The characteristic of the technology offers lot of advantages: • Low power requirement • Low Cost • Short Range of 10 m • Bluetooth Security • Transmission speed of 800 Kbps • 2.4 GHz ISM

29. Bluetooth vs. WLAN • Bluetooth products work over shorter distances and are designed to solve different problems. • Functionality WLAN stand alone as a network component, the functionality of a Bluetooth component requires a host. • The host can be any number of Bluetooth enabled devices: • cell phones, headsets, keyboards, PDAs, vending machines, cameras and bar code readers