When the portable computer returns to the office, a gap usually exists between what is on the portable and what is on the desktop machine. One alternative is to use a docking station to allow the notebook to function as both a portable and as a desktop system. This concept is explored later in this chapter. The other alternative is to make the portable computer network-ready so that it can plug into the network in the office.
Some notebook computer models come from the manufacturer with a built-in network adapter as standard equipment. In other portables, PC Card network adapters can be used with a network socket device so that the portable can be connected to the office network. The socket device has internal circuitry that prevents the open net connection from adversely affecting the network when the portable is removed. Some network adapters use the system's parallel port and a pocket LAN adapter to connect portables to the network. The LAN adapter actually works between the network, the computer, and its printer, as shown in Figure 3.18.
Figure 3.18 Networking portables.
Notebook computers can also be used in dial-up networking environments. Therefore, several newer portable models include built-in modems as standard equipment. Other portables can be configured for dial-up operations by simply installing a PC Card modem, as illustrated in Figure 3.19. These modems slide into Type II PCMCIA slots and connect to the telephone jack through a special phone cable. The cable plugs into a small slot on the card and into the phone jack using a standard RJ-11 connector. Other PC Card modems possess a pop-out RJ-11 port that can be used with standard telephone cables instead of a proprietary cable like the one just described.
Figure 3.19 A PC Card modem.
Wireless Networking with Portables
Notebook computers are natural selections for use as wireless networking clients. Because they are portable, they can be used anywhere within any wireless access point's hot spot. As you will see in Chapter 5, "Peripherals and Ports," many enterprises are creating hot spots to enable traveling computer users to access their access pointfor a fee. Notebook computers typically use PC Cardbased wireless network adapters like the one depicted in Figure 3.20.
Figure 3.20 Wireless networking a notebook computer.
The wireless PC Card adapter slides into one of the notebook's PCMCIA slots and should be auto-detected by the system. The card communicates with a remote access point (or AP) through the embedded antenna that sticks out of the computer's PC Card slot. The device should be capable of functioning on the wireless LAN, provided the card's driver and the operating system's networking components have been set up properly for communications.
Installing Wireless Networking in Portables
Adding wireless communications to portable computers involves the same process described for the desktop computers in Chapter 2, "Adding and Removing FRU Modules in Desktop Systems." Notebook computers typically use a wireless PCMCIA adapter to communicate with the network's access point. For the most part, the installation process involves inserting the wireless card in the PCMCIA slot and supplying the OEM drivers from the manufacturer's CD. Part of configuring the drivers involves identifying the name of the access point that the card should use. Afterward, you simply need to configure networking support in the operating system.
If the wireless LAN has been configured with WEP encryption, the WEP key also needs to be entered into the wireless adapter card's Properties. Wireless Encryption Protocol (WEP) is a security protocol used to protect wireless transmissions from being intercepted and read by unintended users. This protocol is described in Chapter 19, "Basic Networking Concepts."
Because wireless units can and do move, you must be aware of certain wireless connectivity issues. Type 802.11b cards have a limited range of operation (that is, about 500 feet). This estimation relies on a clear line-of-sight pathway existing between the card and the access point. The signals used under this wireless specification do not travel well through objects. In addition, if the card is used in a multiple-access-point environment, it always tries to communicate with the access point it has been configured to use. To switch to another access point, you must reconfigure this setting.
Many wireless configuration applications include a built-in power meter program that shows the relative signal strength being received from the access point. When you're positioning a computer that has a wireless network card, you should use this tool to maximize the location of the computer. Likewise, if you are operating in a multiple-access-point environment, you can use this tool to identify the best access point to use in a given location.