The advent of the 802.11ac Wave 2 standard heralds an era of increased connectivity for multiple users. The standard’s predecessor – 802.11ac Wave 1 – saw increased throughput speeds, but Wave 2 takes that a step further with its ability to have four users concurrently streaming on a connection.
When additional devices are connected to a Wi-Fi network, as instanced with SU-MIMO (single-user, multiple-input, multiple-output) technology, device performance will concurrently slow down because routers can communicate with only one device at a time. MU-MIMO (multiple-user, multiple-input, multiple-output) or 802.11ac Wave 2 technology, on the other hand, allows a Wi-Fi router to provide concurrent downstream communication with multiple devices simultaneously. While it is certainly a boon for home Wi-Fi users, its importance in the business arena should not be overlooked. With an increasing number of employees bringing their own devices to work, connecting to Wi-Fi routers should present less of a problem to IT departments who typically struggle with overloaded networks.
The result is a three-fold increased capability in terms of capacity as well as reduced network latencies, as there isdecreased waiting time for each device to receive a signal, therefore providing an increase in the speed of the network. This is especially relevant when routers are required to handle more bandwidth-intensive activities such as streaming and gaming.
Further benefits are apparent with outdoor Wi-Fi deployments. Using Wave 2 technology means that users can have three times more devices connected to a base station. This means three times more capacity, since three more subscriber modules (SMs) can communicate with the base station simultaneously.
802.11ac Wave 2 offers the option of using 160 MHz channels for improved performance. This allows for high-speed delivery of large files and data access and movement. However, because of the overcrowding of channels with the introduction of Wave 1, there are simply not enough channels left to achieve 160 MHz deployment. So, if you wish to use Wave 2 standards on channels up to 160 MHz channel, then you will need to have access to open channels next to each other.
To optimise this capability, you will require a spectrum analyser that searches for these channels to enable the radio to choose the cleanest channel. For example, MiRO’s Cambium ePMP™ Force 300-25 and PTP550 products institute an automatic, live search using Dynamic Search Optimisation (DSO), to ensure selection of optimal channels. If technology used does not support the search feature, then using Wave 2 means nothing.
Typically gigabit internet, for products like Google Fiber, AT&T GigaPower and Verizon Fios, is confined to hardline connections. However, using the Wave 2 standard may mean opening the door for gigabit Wi-Fi. The PHY (physical) rate, which in turn affects the throughput rate of data transfer, is much higher in Wave 2. The 802.11n could only achieve 450 Mbps and Wave 1 PHY rate maxes out at 1.3 Gbps, while Wave 2 can be as high as 2.34 Gbps. Even if the throughput was 50% lower than the theoretical PHY rate for Wave 2, in theory it would still be above 1 Gbps.
The fourth spatial stream provided with Wave 2 means that, generally, the greater the number of antennas, the greater the distance that a particular data rate can be sustained (depending on the environment). This is a marked differentiator from the previous iterations that supported only three receive antennas, and it signals a move to overall improved performance.
By providing additional 5 GHz channels, Wave 2 allows for greater bandwidth and flexibility for RF to move channels in instances of interference. There are approximately 37 separate channels available in the 5 GHz frequency worldwide. However, some of these are not allocated for Wi-Fi use. As conditions change, 802.11ac Wave 2 will be able to operate in more channels, thereby providing additional bandwidth to support more users, devices and applications.