802.11ac is more evolutionary than revolutionary, building on what were revolutionary technologies in 802.11n, most notably MIMO. Among the key innovations in 802.11ac are wider 80-160 MHz channels and standard beamforming. It also offers better modulation for faster throughput, as well as multi-user MIMO, which transmits individual data streams to multiple receivers simultaneously.
802.11ac will really be about improving reliability, throughput and overall capacity, as was the case with 802.11n. So how should enterprise organizations prepare for 802.11ac? Following are some key recommendations.
1. Perform a wired-network audit.
Robust 802.11ac deployments with three streams and 80-MHz channels will probably not exceed the port capacity of Gigabit Ethernet switches. Nonetheless, there should be 10 gigabit uplinks from the switch to the core — not to connect access points (APs), but to avoid bottlenecks at the switch.
New cable installations should pull two uplink cables to every switch unless fiber is used. While many 802.11ac APs will operate on 802.3af power-over-Ethernet (PoE), switches for new deployments should provision 802.3at just in case and for future contingencies.
Finally, it’s important to look for potential performance problems in the network core and especially in backhaul to the Internet. Reports from the network management console can be invaluable in monitoring and analyzing such data.
2. Plan for coexistence and migration.
Except in rare cases, there should be no need to rip-and-replace equipment to upgrade to 802.11ac. The best approach is a phased, staged, non-disruptive one.
A good place to start is an 802.11ac deployment in a new physical space not previously covered by Wi-Fi. This creates an opportunity for careful evaluation, experience and tuning. The optimal deployment strategy will likely involve setting aside a 40- or 80-MHz channel for 802.11ac.
Given the increasing use of direct-forwarding architectures where traffic to and from APs does not flow through a controller, controller upgrades may not be required. However, as controllers evolve with new features, upgrades may be desirable in many campus WLAN deployments.
3. Re-examine Wi-Fi channel utilization.
The potential for re-designing Wi-Fi channel allocations must be considered. This may occur automatically through radio management features, but verification with appropriate site-survey tools during the initial phase of the 802.11ac deployment is still recommended.
The vastly underutilized 5-GHz band is not likely to create any significant issues. It may be advantageous to run 802.11ac in 40-MHz channels at some locations during initial deployments. Throughput will be lower, but backward-compatibility will improve.
4. Plan for capacity.
Since the advent of enterprise-class wireless LANs more than a decade ago, it has always been advantageous to deploy APs with an emphasis on capacity rather than RF coverage alone.
Optimal 802.11ac performance can be sustained by keeping the distance between endpoints as short as possible. Adopting a dense deployment strategy continues to be a beneficial approach with 802.11ac.
Despite the advances of 802.11ac, wider channels may result in less effective range as RF power spreads across more spectrums and sources of interference. The ever-increasing number of devices and demand for Wi-Fi services will continue to drive high-density deployments.
5. Assess operations and analyze budgets.
Network management capabilities are critical to the success of any enterprise Wi-Fi deployment. IT organizations should discuss with their vendor of choice any anticipated 802.11ac upgrades including the features that will be available to improve ongoing operations.
802.11ac also creates an excellent opportunity to consider unifying wired and wireless management. Enterprise IT organizations should review current and required assurance, compliance and analytics functionality with vendors.
Updating budgetary models is strongly advised. While some 802.11n and 802.11ac designs have appeared at the upper end of current AP prices, mainstream 802.11ac APs will likely not be much more expensive than 802.11n APs.
Finally, one of the most promising high-yield investments an IT organization can make is in an improved enterprise-class management console. The right multivendor, multisite management console will bring positive benefits in operating expense calculations.
There’s no stopping 802.11ac. While upgrades will take some time, it is important to prepare your network now for the arrival of this new technology. Properly planned and executed, this transition can be easy for network operations staff and transparent for users.