Another milestone for 802.11ac and gigabit wireless LANs

This vendor-written tech primer has been edited by Network World to eliminate product promotion, however readers should note it will likely favor the submitter's approach.

Interest in 802.11ac is explained simply by the desire for speed. In homes, the complexity and challenges of A/V or other multimedia distribution and streaming is a catalyst for higher-speed networking, as is anything that improves gaming performance. Enterprise networks may not have as glamorous a need for higher speed, however depend on increasing bit rates to improve user experiences in high-density areas just as conference rooms and auditoriums, improve data service to mobile Internet devices, background synchronization between devices, and support more lifelike video systems.

802.11ac is an evolutionary step in the development of wireless networking. Previous 802.11 technologies have operated in the now-familiar 2.4GHz and 5GHz bands, and the 802.11ac project began with a project authorization at the IEEE that focuses the effort at less than 6GHz.

Wide project authorization that covers both the 2

Even with a wide project authorization that covers both the 2.4GHz and 5GHz frequency bands, the task group developing 802.11ac has decided to focus the new standard on only the existing 5GHz band because much of the benefit from 802.11ac's underlying technologies is derived from wider channels. We don't expect that dual-band APs will go away any time shortly because there are so many devices that are 2.4GHz-only. To continue to build dual-band APs, the industry will build dual-innovation APs with 802.11n remaining the capstone research at 2.4GHz, and 802.11ac offering higher speeds in the 5GHz band.

802.11ac as well has taken the possibility to simplify one promising 802.11n feature: Most access points use omnidirectional antennas that direct radio energy evenly in all directions no matter where the intended receiver of a transmission may be located. With the multiple-antenna arrays required for 802.11n, access points gained the capability of selectively focusing radio energy in a particular direction using a innovation called explicit beamforming. By taking a measurement of the radio channel between two devices, it was possible for an AP to determine how to transmit a signal to focus the energy. 802.11n had multiple ways of performing the explicit measurement, with the unfortunate side effect that none was ever widely adopted. 802.11ac has simplified beamforming by settling on one protocol for explicit measurement.

The rise of smartphones

With the rise of smartphones and tablets, the existence of pervasive wireless LANs is just assumed to exist by most users. The continued development of robust, high-speed technologies just as 802.11ac will meet the needs of users for the at once several years. [As well see: "Wi-Fi client surge forcing fresh wireless LAN thinking"]