CHAPTER 2: WIRELESS NETWORK FUNDAMENTALS
Wireless Network Configuration
Ad-hoc Mode (Peer-to-Peer Workgroup)
The Institute of Electrical and Electronics Engineers (IEEE) standard for wireless LANs (WLANs), 802.11, offers two methods for configuring a wireless network — ad hoc and infrastructure. In an ad hoc network, computers are brought together as needed; thus, there is no structure or fixed points to the network — each node can generally communicate with any other node. There is no access point involved in this configuration. It enables you to quickly set up a small wireless workgroup and allows workgroup members to exchange data or share printers as supported by Microsoft Networking in the various Windows operating systems. Some vendors also refer to ad hoc networking as
In this configuration, network packets are directly sent and received by the intended transmitting and receiving stations. As long as the stations are within range of one another, this is the easiest and least expansive way to set up a wireless network.
To set up an ad hoc workgroup operating with standard protocols, do the following:
ySet all stations to connect in
ySet all stations to use the same network name (or SS ID).
ySet all stations to use no WEP encryption key or an identical WEP encryption key.
ySet all stations to use the same wireless channel for communication.
Infrastructure Mode
With a wireless access point, you can put the wireless LAN into the infrastructure mode. It provides wireless connectivity to multiple wireless network devices within a fixed range or area of coverage, interacting with a wireless nodes via an antenna.
In the infrastructure mode, the wireless access point converts airwave data into wired Ethernet data, acting as a bridge between the wired LAN and wireless clients. Connecting multiple access points via a wired Ethernet backbone can further extend the wireless network coverage. As a mobile computing device moves out of the range of one access point, it moves into the range of another. As a result, wireless clients can freely roam from one Access Point domain to another and still maintain seamless network connection.
To set up an infrastructure network operating with standard protocols, do the following:
ySet all wireless stations to connect in infrastructure mode
ySet all stations to use the same network name (or SS ID).
ySet all wireless access point to use the same network name ( or ESS ID).
ySet all stations to use no WEP encryption key or an identical WEP encryption key.
ySet up wireless channels used by individual access point. (It is not necessary to set channels on the stations as the stations will automatically scan through all channels for the nearest access point.)
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