Which of the following devices allows wireless communication devices to connect to a wireless network using Wi-Fi, Bluetooth, or related standards?
- Express card
- WAP
- WNIC
- Wireless repeater
- None
Answer(s): B
Explanation:
A wireless access point (WAP) is a device that allows wireless communication devices to connect to a wireless network using Wi-Fi, Bluetooth, or related standards. The WAP usually connects to a wired network, and it can transmit data between wireless devices and wired devices on the network. Each access point can serve multiple users within a defined network area. As people move beyond the range of one access point, they are automatically handed over to the next one. A small WLAN requires a single access point. The number of access points in a network depends on the number of network users and the physical size of the network.
Answer option C is incorrect. A wireless network interface card (WNIC) is a network card that connects to a radio-based computer network, unlike a regular network interface controller (NIC) that connects to a wire-based network such as token ring or ethernet. A WNIC, just like a NIC, works on the Layer 1 and Layer 2 of the OSI Model. A WNIC is an essential component for wireless desktop computer. This card uses an antenna to communicate through microwaves. A WNIC in a desktop computer is usually connected using the PCI bus.
Answer option A is incorrect. ExpressCard, a new standard introduced by PCMCIA, is a thinner, faster, and lighter modular expansion for desktops and laptops. Users can add memory, wired or wireless communication cards, and security devices by inserting these modules into their computers. ExpressCard slots are designed to accommodate modules that use either Universal Serial Bus (USB) 2.0 or the PCI Express standard.
ExpressCard modules are available in two sizes, i.e., 34 mm wide (ExpressCard/34) and 54 mm wide (ExpressCard/54). Both modules are 75 mm long and 5 mm high. An ExpressCard/34 module can be inserted in either a 54 mm slot or a 34 mm slot, but an ExpressCard/54 requires a Universal (54 mm) slot. However, an extender can be used with ExpressCard/34 slot to connect the ExpressCard/54 module from outside of the computer. Both the modules are identical in performance. They take full advantage of the features of the PCI Express or USB 2.0 interfaces. The only difference between them is that the ExpressCard/54 form-factor, due to its larger surface area, allows for greater thermal dissipation than does an ExpressCard/34. As the performance does not vary with module size, module developers usually prefer to fit their applications into the smaller ExpressCard/34 form factor. But some applications, such as SmartCard readers, and CompactFlash readers, require the extra width of an ExpressCard/54 module.
Answer option D is incorrect. A wireless repeater is a networking device that works as a repeater between a wireless router and computers. It is used to connect a client to the network when the client is out of the service area of the access point. If the wireless repeater is configured properly, it extends the range of the wireless LAN network.