Section 6.7. Summary

6.7. Summary

This chapter presented basics of wireless networking without touching on the large-scale routing issues. Starting with the fundamental concept at the LAN level, we analyzed several IEEE 802.11 standards. The basic versions802.11a, 802.11b, and 802.11g typically use Carrier Sense Multiple Access with collision avoidance (CSMA/CA).

A cellular network , includes a networked array of base stations , each located in a hexagonal cell to cover networking services. Each mobile user should register with the regional mobile switching center . Because of unexpected interference whenever a user works with radio frequencies, we looked at known interference and frequency reuse . Frequency reuse in a certain region of a wireless network occurs when the same frequency used in one area could be reused to cover another area.

We also studied mobile IP. We learned that this protocol is responsible for handling the mobility of users attached to the Internet. A mobile host is allowed to hold two addresses simultaneously : a home address and a foreign address. One of the main elements of mobile IP is registration in a foreign network.

At the end of this chapter, we introduced wireless mesh networks (WMNs), including WiFi and WiMAX technologies. The wireless fidelity (WiFi) technology is a set of standards for wireless local area networks that allows mobile devices, such as laptop computers, digital cameras , and personal digital assistants, to connect to local area networks. The world wide interoperability for microwave access (WiMAX) technology is the IEEE 802.16 standard that can connect IEEE 802.11 WiFi hotspots to one another and to other parts of the Internet. We also looked at wireless mesh networks (WMNs) constructed as a wireless network backbone for several applications.

In the next chapter, we study routing and internetworking issues in widearea networks. We explore how routing algorithms and protocols are performed both within and beyond a single wide area network.