Wi-Fi is the popular name for IEEE Standard 802.11x which was established in 1997. It has grown to become the go to technology for unlicensed wireless access to the internet. In commercial applications it is also referred to as the Wireless Local Area Network or WLAN.
RF Frequencies: 2.4 GHz and 5.0 GHz
802.11 A is dual band and utilizes both frequencies
802.11 N still being deployed and offering up to 500
802.11 AC is the latest standard. It generally is dual band using 2.4 GHz and 5.0 GHZ. This significantly increases speed up to 10 Gigabits.
Performance Factors: Distance, Throughput, Users, Scalability
Access Point is the physical device that is at the edge of the network communicating with the device or thing.
Controller is now an optional point of a wi fi system. The systems that use controllers utilize thin AP’s and provide the functionality,switching and security.
Virtualized Controller is where the AP’s have advanced chip sets and memory and communicate via the internet to a virtual controller that helps in updating and reconfiguration.
Craig Mathias contributed this discussion on the much higher degree of variability in the architecture of WLAN systems and solutions. This model is based on the concept of planes, to describe the internal functions of a given WLAN architecture. These planes are as follows:
Data Plane – This describes how data moves within the WLAN. The biggest question is whether data from an access point (AP) can be forwarded directly to its destination, or whether this data must flow through a separate physical element, called a controller.
Management Plane – This describes how the system is configured, monitored, and how many other required functions are implemented. The management function is almost always centralized in a single location, even for large, distributed, and multi-vendor solutions. The point of residence can also be in a controller, or a separate appliance or server.
Control Plane – This plane can be thought of as the “operating system” of the WLAN, executing policies defined by the Management Plane and optimizing the flow of data in the Data Plane. And, you guessed it, such functionality also often resides in a controller (which can even be virtual in some products), or can be distributed across the APs. Controller functionality can also move among elements in some implementations.
The Data Plane should be as distributed as possible, and that the Management Plane must be centralized. So it's the Control Plane that presents the greatest opportunity for controversy, as it can be fully distributed and implemented in an AP, reside in a server, or, again, live in a separate box, the controller. While vendor arguments are plentiful and often persuasive, there's not enough empirical (based on appropriate benchmarks) or analytical (the results of mathematical models of system behavior given specific configuration and loading) to provide a definitive argument either way. One can certainly make the argument that a controller adds cost (and that additional or redundant controllers may be required to handle certain loads and/or provide fault tolerance), but one must consider the total cost of a given solution, not the cost of individual elements. And one can make the argument that a controller-based implementation provides a more global view of system condition and behavior, and thus could yield higher performance especially over time.
Hot Spot 2.0
Voice over Wi Fi