Five Steps to Successfully Migrate to 802.11ac

802.11ac is well on its way to becoming the standard for next-generation Wi-Fi. The gigabit speed, improved capacity and reliability that 802.11ac brings to wireless LANs (WLANs) are amplified as mobile users, devices and application usage continue to grow rapidly.

Whether you are an early adopter who has already started planning, or like several organizations, unsure of your next step, the following guidelines will help you prepare and plan for a successful migration to an 802.11ac WLAN.

Note that migrating to 802.11ac will require hardware replacement. Older 802.11n access points cannot be upgraded to 802.11ac. However, 802.11ac is backwards compatible so you can migrate gradually from 802.11a/b/g/n.

1. Audit current infrastructure.
Since 802.11ac is all about gigabit Wi-Fi, it is important that the supporting infrastructure is optimized to leverage all that 802.11ac access points (APs) have to offer.

• Is the wired network 802.11ac-ready? To avoid traffic congestion at the switch, be sure that your access switches support at least 10-gigabit uplinks. Additionally, to avoid performance degradation, the access switches will need to support PoE+ (802.3at) on every port. Although 802.11ac APs may operate on 802.3af in some cases, several tests have shown a need for more than 20 watts for optimal performance. So, planning for 802.3at is recommended.
• Will the controller need to be upgraded? In a controller-based deployment, upgrading the controllers may be considered to maximize capacity, but at a minimum, ensure they are 802.11ac-aware. For example, the ability to address 256 quadrature amplitude modulation (QAM) and multi-user MIMO.

2. Evaluate capacity requirements.
As traffic demands continue to grow exponentially, take both current and future demands into consideration when planning for capacity.

• How many mobile devices will need to be supported? Plan for at least three devices per user (laptop, tablet, and smartphone), and 20-30 devices per radio or 40-60 per dual-radio AP.
• How many devices will be active simultaneously? Evaluating both how active the devices are and the type of devices will effect capacity, and important for determining AP density.
• What applications will be used? Voice over Wi-Fi? Multicast video over Wi-Fi? Determine coverage versus capacity requirements by planning for roaming and calculating AP signal strength based on bandwidth demands and application prioritization.

3. Evaluate RF requirements.
Virtual planning tools can provide basic foundation in planning for standard deployments, but an additional physical survey is recommended for complex deployments to verify AP locations and signal coverage. Note that in most cases 1-for-1 replacements are not viable for building an optimal 802.11ac network, especially in complex deployments.

• Which RF bands will be used (2.4 GHz, 5 GHz)? Due to increasing client density, always plan to use both bands.
• What channel width (20 MHz vs. 40 MHz vs. 80 MHz) will be used in each band? Typically 20 MHz channels are used in 2.4 GHz, and 40-MHz and 80-MHz channels are used in the 5-GHz band. In dense deployments, speed may be traded off for capacity in the 5-GHz band by reducing to a 20- or 40-MHz channel.
• Will real-time location services (RTLS) be used? Consider deploying air monitors around the building perimeter to help with location accuracy. This deployment ensures that all clients are within the triangulation zone.

4. Choose the right APs.
Once all the preliminary evaluations are complete, choose APs and antenna types that are best suited for the environment to provide optimal performance and RF coverage.

• What are some unique capabilities to consider? Mobile device clients tend to stick to one AP as they roam instead of associating with one that’s closer and has a stronger signal. Access points that can eliminate sticky clients and do not cripple the 802.11ac capabilities are highly recommended.

5. Determine deployment plan.
New deployments are fairly easy to plan, but if a phased approach is preferred, it is important to understand that how you rollout could impact performance and user experience.

• Upgrading from 802.11n? It is recommended that one floor or building at a time be upgraded with new 802.11ac APs.
• Upgrading from 802.11a/b/g? Upgrading one building at a time is recommended. This approach gives devices in that area the best chance of remaining connected to the network, providing a better user experience.
• Considering mixed deployments? In the past, deploying then-new 802.11n APs with legacy 802.11 a/b/g APs resulted in client behavior problems related to device roaming. Similarly, roaming from an 802.11ac 40-MHz or 80-MHz channel to an 802.11a/g 20-MHz channel will cause some devices to stick to the higher speed AP. To avoid an unpredictable client experience, mixed deployments are not recommended.

While there might be several items to consider for successfully migrating your current network to 802.11ac, this is possibly the best time to start planning. Discover other 802.11ac resources.

Making the Move to 802.11ac: A Practical Migration Approach for Modern Networks

Start by Understanding What’s Actually Happening on Your Network

The worst thing you can do before a network upgrade is assume you already know where the problems are. Most organizations have a rough sense, “the conference rooms are always bad,” or “the warehouse drops connections constantly,” but a rough sense isn’t enough to design a solution around.

Before touching any hardware, build an honest picture of current network behavior:

• What does bandwidth usage actually look like at peak times, by area?
• How many devices are connecting per zone, and what kinds?
• What applications are driving the most traffic — video calls, cloud apps, large file transfers?
• Where do connections fail or degrade consistently?
• How does roaming perform when workers move between access points?

This baseline does two things. First, it tells you whether your current problems are capacity issues, RF design problems, or just aging hardware that needs replacing. Second, it gives you something to measure against after deployment, so you know whether the upgrade actually worked.

Skipping this step is how organizations spend significant money on new hardware and end up with roughly the same experience they had before.

The Wired Network Has to Keep Up

802.11ac pushes significantly more wireless throughput than older standards. That’s the whole point. But all that wireless traffic eventually hits a wire, and if the wired infrastructure isn’t ready for the increased load, the access points become a bottleneck waiting to happen.

A few things worth checking before deployment:

• Do uplinks to switches have enough capacity to handle the higher traffic volumes?
• Are all access point locations covered by PoE+ capable switches? 802.11ac APs draw more power than older hardware and need proper support.
• Can switch backplanes handle traffic spikes without becoming a choke point?
• Is VLAN segmentation set up sensibly for the way traffic actually flows?
• In managed deployments, can the controller handle the expanded client load?

It sounds like infrastructure housekeeping, and it is, but it’s the kind of housekeeping that directly determines whether the wireless upgrade delivers what it promised. A great access point connected to an undersized switch won’t perform like a great access point.

Choosing Access Points for Real Workloads

Not all 802.11ac access points perform the same way in real deployments. The spec sheet numbers are measured in ideal conditions. What matters is how the hardware performs when it’s loaded with real clients running real applications.

Things worth looking for:

• How many simultaneous clients does the AP handle well before performance degrades?
• Does it support beamforming and directional signal optimization that improve performance for specific clients rather than broadcasting in all directions equally?
• Multi-user MIMO capability, which allows the AP to serve multiple clients simultaneously rather than sequentially
• Load balancing across APs so clients distribute sensibly rather than piling onto the nearest one.
• Fast roaming support for environments with mobile workers or devices that need to move between APs cleanly

That last point about sticky clients deserves attention. A sticky client is a device that stays connected to a weaker AP signal when a stronger one is nearby, because the device decides when to roam, not the network. In large facilities, this creates dead weight on distant APs while nearby ones sit underutilized. Good hardware and configuration can nudge clients toward better connections, but it requires the right capabilities and deliberate setup.

Validate That It Actually Worked

Deployment complete doesn’t mean migration complete. The final step is confirming that the network performs the way it was designed to.

That means checking:

• Signal consistency across every zone, not just the areas that were obvious during planning.
• Roaming behavior as workers and devices move through the facility
• Application performance under realistic load, not just pinging the gateway, but actually running the video calls, cloud apps, and data-heavy workflows the network needs to support
• Latency for real-time applications, where even modest delays cause noticeable degradation
• Connection stability during peak usage when client counts are highest

Ongoing monitoring after validation matters too. Network usage patterns shift over time. New applications get deployed. Device counts grow. The configuration that was right at go-live may need adjustment six months later as the environment changes.