The past fortnight has been a highly significant one in the world of WiFi. It is testament to the effort of teams behind the scenes both at standards bodies and vendor R&D departments that the market is thriving despite the huge focus on 5G, and claims from some quarters that 5G – especially when it reaches unlicensed spectrum – will make WiFi redundant over time, at least outside the home. But the variety of new developments we have seen in July so far show how the WiFi community will leverage the home incumbency to drive new experiences that can then be applied to broader markets including enterprise, public access, vehicles and the Internet of Things.
The Wireless Broadband Alliance (WBA) has baked a tray of deployment guidelines for WiFi 6 (802.11ax), iced with a set of scenarios for the next generation WiFi technology rolling out later this year. It intends to familiarize service providers with the taste of WiFi 6 in this critical period amid 5G network roll-outs, but have too many cooks spoiled the broth?
The 40-page guidelines cover four broad topics, spanning RF planning and design, infrastructure service level agreements (SLAs), seamless mobility, and preparation for coexistence.
The most detailed section relates to 12 SLAs against which a WiFi network can be measured. WiFi 6 is designed to significantly improve the performance of a number of concurrent users with multiple specific design principles, which impacts heavily on the number of business support systems (BSS) and backhaul requirements for a given coverage. The introduction of uplink multiple user access, including both UL OFDMA (Uplink Orthogonal Frequency Division Multiple Access) and UL MU-MIMO, will especially enable more concurrent accesses to the radio resources, according to the WBA.
UL OFDMA and UL MU-MIMO are cited throughout the report, credited for boosting power and range, with higher spectral efficiency, for example providing ideal for use in stadium builds given the increased demand for video upload, where it is common to limit the end user to speeds to just 2Mbps to 5Mbps.
However, when detailing packet loss, the WBA warns that if even a single station is unable to adhere to the maximum allowed time or frequency offset, then the access point (AP) will not be able to decode either of the set of high efficiency trigger-based PLCP Protocol Data Unit from multiple users in response to a trigger frame. In other words, the entire UL OFDMA frame exchange will be regarded as corrupted and need re-transmissions.
So WiFi 6 will include latency-reducing techniques like OFDMA, a battery-saving technique called Target Wake Time, and of course MU-MIMO which can increase capacity when serving a small number of high bandwidth clients – ideal for managed services such as high-bandwidth video applications operating in the 5 GHz band.
Meanwhile, because 2.4 GHz is often congested with legacy clients (802.11b/g/n), the WBA says when (or if) the 6 GHz band becomes available, it will extend the 5 GHz band to free up unprecedented capacity for gigabit broadband access, allowing WiFi 6 to serve next generation mission critical applications.
In terms of deployment scenarios, the report cites massive investment in the USA to upgrade cable networks, with the cable industry having recently launched its 10G initiative and 80% of cable gigabit services now available to 80% of housing units. This is given as a critical reason why subscribers must experience the enhanced speed on the wireless network too.
Staying in the residential space, the WBA cites non-managed multi-dwelling units (MDUs) as the most challenging environment. This is due to rogue overlapping APs, ever-changing channel configuration and a higher client density. It advises multi-AP set ups for larger premises running the EasyMesh standard for facilitation of client and band steering, while defining a communications protocol for easy onboarding, provisioning, control and automated management of APs.
As with any new standard, WiFi 6 guidelines will grow as field trials are executed, producing results to evolve the technology accordingly.
An early example is Boingo Wireless, which has been trialing WiFi 6 at John Wayne Airport in southern California, deploying Cisco WiFi 6 technology to allow airport staff to carry out day-to-day admin tasks as well as streaming high bandwidth content on pre-released Samsung Galaxy S10 handsets, fitted with WiFi 6 chipsets.
Boingo has reported high data rates, ultrafast speeds, and no buffering, though not offering any actual data. The trial will continue to explore new applications, particularly testing whether WiFi can meet key 5G requirements for a range of connected use cases in dense environments.