WLAN Components
Wireless Network Cards
To have successful wireless communication, a minimum of 2 devices that have a radio transmitter and a radio receiver which are tuned to the same radio frequency is required:
- End devices with wireless NICs
- A network device, like for example a Wireless router or Wireless Access Point
If a device does not have an integrated Wireless network card (NIC), an additional PCI-e Wireless NIC or a USB NIC can be purchased and used with that device.
A lot of antennas are built into devices and are not visible like for example smart-phones, tablets and laptops
Wireless Home Routers
This is the device that an end device will associate and authenticate with and it varies based on the size and requirement of the WLAN.
Home users typically connect to small wireless routers which can also serve as an Access point, a Switch and a Router all in one.
For example, a home user typically uses a small all-in-one router which can act as the following
| Access Point |
| Provides 802.11 a/b/g/n/ac wireless signal |
| Switch |
| Provides 4 full-duplex ports @ 10/100/1000 Ethernet speeds to connect wired devices |
| Router |
| Provides as a default gateway for connecting to other networks like for example, the internet |
Such router is usually implemented domestically or within a small business. The router will advertise it’s wireless services by sending beacons containing the SSID (Shared Service Set Identifier)
A wireless router is commonly implemented as a small business or residential wireless access device. The wireless router advertises its wireless services by sending beacons containing its shared Service Set Identifier (SSID).
When broadcasting the SSID, other devices will wirelessly discover it and attempt to associate and authenticate with it to obtain access to the local network and the internet.
Most of the wireless routers nowadays, provide also advanced features like for example high-speed access, streaming support, IPv6, QoS, and more…
A home user may also choose to extend the network via WiFI Range extenders which are not highly scalable. A device will connect to such extender and the extender will boost the signal.
Wireless Access Points (APs)
Range extenders are used in small environments like for example households and small offices. As mentioned earlier, they are not highly scalable and another solution must be used in large businesses.
The best solution would be to opt for Wireless Access Points (APs) to provide dedicated wireless access to end-user devices that are using their wireless NIC card to discover nearby Access Points advertising SSIDs
There are 2 different types of Access Points
| Autonomous Access Points |
| These are standalone devices configured manually one by one using Command-Line or GUI. Such access points are used when only a few of them are required since each and every single access point operates individually and will require manual configuration and management. This would become too complicated to manage if loads of access points are required. |
| Controller-Based Access Points (CBAs) |
| Also known as LAPs (Lightweight Access Points). Such access points use what’s known as an LWAPP (Lightweight Access Point Protocol) to communicate with a WLC (WLAN controller). Such access points are used in large areas where a lot of access points are required. When plugged-in each AP can be adopted to the same controller and will be automatically configured and managed by that same controller. The ports on the switch interconnecting the Access Points will need to be configured in trunking mode so that all specified VLANs will have access when connected via such Access Point. |
Wireless Antennas
Many professional Access Points usually require external antennas to make them fully functional. There are a total of 3 types of antennas:
| Omnidirectional Antenna |
| Such antennas provide 360-degree coverage and are ideal for domestic use, open office environments, rooms, and outside areas. |
| Directional Antenna |
| Such antennas focus the signal into a given direction (aka. beam-forming antennas). This will improve the signal to/from the Access Point in the direction the antenna is pointing resulting in stronger signal strength in one direction and reduce signal strength in all the other directions. Examples of this are Yagi and Parabolic dish Antennas. |
| MIMO Antenna |
| Multiple Input Multiple Output (MIMO) uses multiple antennas to increase available bandwidth for IEEE 802.11n/ac/ax wireless networks. Up to a maximum of 8 transmit/receive antennas can be used in conjunction to increase throughput. |