The average worker has a primary computing device, usually a laptop, and at least one other mobile device, usually a smartphone. Many workers also carry tablets for collaboration, presentations, training and other uses. As the number of devices per user increases, competition for bandwidth on the wireless network increases.
The problem is, most wireless networks were designed to provide simple coverage, not to support high device density or meet the performance demands of modern business applications. Remember, the first iPad wasn’t even introduced until 2010.
In recent years, the 802.11ac Wi-Fi standard has helped to overcome this challenge, offering faster speeds, higher capacity, more reliability, and connectivity over longer distances. However, 802.11ac technology is now struggling to keep up with demand. Beyond desktop and mobile devices, you have Internet of Things (IoT) devices that are constantly transmitting data and contributing to Wi-Fi congestion.
The problem with 802.11ac is that it’s basically a faster version of an older model in which bandwidth is shared among devices, access point coverage areas overlap, and devices have to wait for a clear path to the access point. If there’s interference or congestion, the device has to wait, which causes inefficiency and performance degradation.
The demand for more performance and capacity has brought us 802.11ax, or high-efficiency wireless. 802.11ax was designed for high-density public spaces, such as train stations, airports, conference centers and stadiums. But organizations struggling to support high-density environments and bandwidth-hungry applications such as videoconferencing stand to benefit as well.
802.11ax overcomes the shortcomings of 802.11ac in a number of ways. The new standard increases pure throughput by almost 40 percent. Improvements in quadrature amplitude modulation (QAM) enable the transmission of more data per packet and more efficient spectrum utilization. 802.11ax creates wider channels, which are divided into narrower sub-channels. With more available channels, wireless devices have more paths to the access point, resulting in higher performance and efficiency.
802.11ac Wave 2 technology used Multi-user, Multi-Input, Multi-Output (MU-MIMO) to enable four simultaneous streams per access point. 802.11ax supports twice as many simultaneous streams and uses beamforming to precisely direct each stream toward the receiver’s antenna. Using Orthogonal Frequency Division Multiple Access (OFDMA) technology, 802.11ax divides each MU-MIMO stream into four streams, which quadruples the available bandwidth per user.
802.11ax opens up more available channels by operating in both the 2.4Ghz and 5Ghz spectrums, and also supports simultaneous downlink and uplink transmissions. In other words, an access point with downlink MU-MIMO can transmit to multiple streams while uplink MU-MIMO allows devices to receive transmissions from multiple sources at the same time.
In addition to OFDMA, 802.11ax includes a number of new technologies and capabilities, including trigger-based random access, dynamic fragmentation, spatial frequency re-use and target wake time. These enhancements are designed to boost efficiency and extend battery life.
Pre-standard 802.11ax products are already hitting the market. Generally, it’s safe to adopt these products because they’re backward compatible and typically certified with a firmware upgrade. However, if you feel like you’re not ready to make the move to 802.11ax, there are ways to maximize Wi-Fi capacity with existing technologies. In the next post, we’ll discuss the differences in designing a Wi-Fi network for coverage vs. capacity and how to overcome the challenges of capacity planning.