Hardware Requirements & Configuration
Typical Wireless LAN hardware includes the following:
- A PC Card, type 2 format, either with integral antenna. This is becoming the norm, or a Card with a tethered antenna/RF module.
- An ISA Card with external antenna connected by cable.
- Handheld terminals with integrated radios for vertical market applications such as warehousing.
- Access points that are stand-alone devices.
- A Client LAN adaptor.
There are two integral parts to a wireless LAN: an access point and a client LAN adapter.
The access point is a device that connects to the wired LAN and translates between the cabled Ethernet LAN and the radio link. It contains a 10Base-T port that connects to the LAN's hub or switch, communications and encryption software, and a radio transceiver. The client LAN adapter is typically a PC Card that fits into a portable device, although many vendors also offer ISA and PCI cards. The notebook, personal access device, or specialized device such as an inventory scanner or medical monitor sees the PC Card as an Ethernet adapter. The client adapter has a small integrated antenna.
The client adapter uses its radio transceiver to find an access point and negotiate a connection speed appropriate to the signal quality. If you want your wireless LAN to cover more than a few thousand square feet, you'll need more than one access point. Exact coverage depends on the building's construction and layout, but plan for a connection radius of several hundred feet in clear view and perhaps 50 to 60 feet going through walls, floors, and ceilings. As the user moves, the radio connection transfers to another access point, a process called "roaming". Maximum connection speeds are up to 11 Mbps; A radio LAN is generally rated at 10 Mbps.PC Cards
A PC or LAN Card (also known as a PCMCIA card) is a credit card-size memory or I/O device that fits into a personal computer, usually a notebook or laptop computer. The most common example of a PC Card is the 28.8 Kbps modem for notebook computers. There are 16-binary bit and 32-bit (CardBus) varieties of PC Cards. Another type of PC card is the ZV Card.
A card is used as an interface to connect to a PC. Most cards are in Pcmcia ISA and PCI versions. Other vendors offer an ISA-to-Pcmcia bridge to allow you to plug a Pcmcia card in a desktop.
Planning on establishing point-to-point links? Then you will need the card to offer a connector for an external antenna. LAN cards are often plugged into routers.Routers
A router is a device or software in a computer, that determines the next network point to which a packet should be forwarded toward its destination. The router is connected to at least two networks and decides which way to send each information packet based on its current understanding of the state of the networks it is connected to. A router is located at any gateway (where one network meets another), including each Internet point-of-presence. A router is often included as part of a network switch.
A router may create or maintain a table of the available routes and their conditions and use this information along with distance and cost algorithms to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination. Routing is a function associated with network layer in the standard model of network programming, the Open Systems Interconnection (OSI) model. A layer-3 switch is a switch that can perform routing functions. Access Points or "residential gateways"
Some vendors offer an Access Point or "residential gateways". An Access Point is a bridge that allows you to connect the wireless network to an Ethernet backbone, whereas the Residential Gateway connects it to an ISP. An Access Point allows the Wireless LAN to be a natural extension of a wired network. They are deployed in a cellular fashion, and provide extended security, management and roaming. NOTE:
These two kinds of products are usually not fully interchangeable.Wireless Bridges
A Wireless Bridge is connected to one of the LAN sections and redirects the traffic over the air to the correct destination. There are many products on the market, they can be slightly expensive but are very flexible, transparent and optimized for the task.Drivers
A driver is a program that interacts with a particular device or special kind of software. The driver contains the special knowledge of the device or special software interface that programs using the driver. In personal computers, a driver is often packaged as a dynamic link library file.