Applies To: WatchGuard Cloud-managed Access Points (AP130, AP330, AP332CR, AP430CR, AP432)
Before you deploy Wi-Fi in WatchGuard Cloud access points on your network, you must research, design, and plan your wireless network deployment to make sure it meets your requirements for coverage, capacity and airtime demand, and security.
Evaluate Requirements
When you evaluate your current environment and wireless requirements, make sure to consider:
- What wireless modes must your access point support (802.11ax, 802.11ac Wave 1 and Wave 2, 802.11a/b/g/n)?
- What types of wireless clients do you want to allow to connect?
- What wireless modes do they typically support?
- What SSIDs and networks do you want to create?
- Are there groups of wireless users who need wireless access to different network resources?
- Do you want to set up a guest wireless network that only allows Internet access?
- Where is the best physical location for each access point?
- What is the physical size of the environments wireless users will connect from?
- Do you need more than one access point to cover multiple areas?
Coverage Planning
Traditional coverage planning examines the physical environment where the wireless network will be deployed and the different factors that can affect your wireless signal power, range, and attenuation.
Coverage planning provides:
- Optimal frequency usage and access point locations
- Determination of transmit power levels
- Prevention of channel interference
- Examination of floor plans, physical obstructions, and building materials
Capacity Planning
As part of your wireless deployment planning you must also consider capacity and airtime demand. You must factor in to your plan the expected peak airtime demand amount and type of traffic, and traffic patterns for your wireless network and the coverage area it serves.
For example, a deployment for a hotel and its conference rooms has very different capacity and airtime demand criteria than a deployment for a small office, a retail department store, or a school campus. Each wireless deployment is unique and requires both coverage and capacity planning.
Capacity and airtime demand analysis provides:
- Optimal number of clients per access point radio, including idle and active clients. You must factor in slow periods and worst-case usage scenarios.
- Airtime demand and minimum data rates for different types of application traffic.
- Include email, web, video, social media, streaming, and other applications.
- Determine bandwidth throughput per application and connection, then determine aggregate bandwidth required in the wireless network coverage area.
- Considerations for growth, based on the number of connected clients and application bandwidth usage
Wireless Site Survey
Complete a wireless site survey to analyze your physical environment and existing wireless signals. Use a wireless site survey utility, such as AirMagnet Planner, or any other similar tool.
- Measure before the deployment as part of your plan
- Measure any existing wireless signals and interference in your environment
- Measure wireless signal strength at different locations.
- Measure after the deployment to see the access point signal strength and range
- After you install your access points, make another heat map to verify that your current placement provides adequate coverage and signal strength.
- Check for wireless channel congestion and make sure the distance between access points does not degrade the signal to problematic levels.
WatchGuard Predictive Site Surveys
WatchGuard can assist partners with predicative site surveys for customers. WatchGuard provides to partners a Wi-Fi Customer Requirements Questionnaire that specifies the data required to create a predictive site survey for the deployment. The site survey includes sizing information for the number and types of access points required by the wireless network, and a deployment floor plan with suggested access point placement.
To download the questionnaire, log in to your partner account on the WatchGuard web site and go to Product > Selling Secure Wi-Fi.
For more information, see WatchGuard Wireless Site Survey.
Channel Capacity Planning
Most wireless networks are designed for capacity rather than coverage, especially in educational environments where high client densities and high bit rate applications, such as video streaming, are common.
To design networks based on capacity, the first step is to define the requirements that include client density, client types, applications, use cases, and throughput requirements.
For a successful design, you also need other information related to the environment. This includes factors such as Wi-Fi spectrum availability, building layouts, building materials used, and neighbor Wi-Fi channel usage.
The design process includes these analysis and planning stages:
- Requirements Analysis
- Clients
- Applications
- Use Cases
- Wireless Environment Analysis
- Channel Capacity Planning
Requirements Analysis
Clients
You must determine the number and types of client devices and where they are located on the network. Channel capacity and overall network capacity are as much a function of the client population as the types of deployed access points and switches.
While it is not always possible to know the exact breakdown of client capabilities (for example, 802.11ax vs 802.11ac Wave 1 or Wave 2, 1x1, 2x2, and 3x3) for a given area of the network, the more details that you know, the more accurate your channel capacity planning will be. Often you can use monitoring tools in the current Wi-Fi deployment to gather details about the clients in use on your network.
Applications
You must determine which applications are typically used on your wireless client devices. To estimate a per-client Mbps throughput requirement for a given area of a deployment, use the application with the highest bit rate. For example, in a classroom the highest bit rate application could be HD video streaming at 5 Mbps. For this use case, we recommend a per-client throughput requirement of 5 Mbps. To determine which applications are used by your wireless clients, you can use application visibility tools on your current wireless network.
It is also important to consider the requirements for applications that you plan to use in the future. We recommend you communicate with IT personnel about proposed future application use.
These are reference approximate bit rates for common applications. You can use these values to calculate approximate capacity requirements.
|
Application |
Approximate Average Bit Rate |
|---|---|
|
Audio |
100–1 Mbps |
|
File Backups |
20–60 Mbps |
|
File Sharing |
5 Mbps |
|
On-Line Testing |
2–4 Mbps |
|
Printing |
1–3 Mbps |
|
Video Conferencing: Standard Definition |
5–1 Mbps |
|
Video Conferencing: High Definition |
2–3 Mbps |
|
Video Gaming* |
Requires measurements |
|
Video Streaming: Standard Definition |
1 Mbps |
|
Video Streaming: High Definition 720p |
3–5 Mbps |
|
Video Streaming: High Definition 1080p |
8–12 Mbps |
|
Video Streaming: UHD (4K) |
18–25 Mbps |
|
Webinars |
1 Mbps |
|
Web Browsing |
750 Kbps |
Use Cases
A use case is defined as the number and types of devices and their applications and usage patterns for a specific location. To learn about use cases for a deployment, we recommend you perform a thorough site walk-through with IT personnel familiar with the current network.
Wireless Environment Analysis
There are several environmental factors that can affect the range and performance of wireless networks. You must estimate the path loss and attenuation of your wireless signals because of these factors.
Walls and ceilings
Walls and ceilings between the access point and wireless clients can degrade signal strength. Wireless signals can penetrate walls and other structures, but the rate of penetration is directly related to the type of building materials, material thickness, and the distance from the wireless antenna.
Building materials
Metal and aluminum doors, glass, concrete, metal studs, brick walls, glass, and other types of building materials can have a significantly negative effect on the strength of wireless signals.
EMI (Electro-magnetic interference)
EMI from other electrical devices, such as microwaves, cordless phones, and wireless headsets can generate significant RF noise and degrade or disrupt wireless communications.
Distance
Wireless signals degrade quickly past their maximum range. You must plan your network carefully to provide adequate wireless coverage over the range you require in your environment.
Channel Capacity Planning
As part of capacity planning you must review and understand the wireless spectrum availability to help guide the planning process.
The number of channels potentially available for a deployment depends on the regulatory domain of the country where the deployment is located. Some regulatory domains have greater spectrum capacity than others. The amount of spectrum available for a given deployment has a direct impact on the types of uses cases you can support.
About DFS Channels
In some regions, you can enable additional DFS (Dynamic Frequency Selection) channels that operate in the 5 GHz band. DFS channels are also used by radar systems, and transmissions from your access point stop if radar signals are detected on that channel.
Many networks rely on DFS channels to meet higher scalability requirements.
We recommend you enable DFS channels if they are available, and that you provision both 5 GHz and 2.4 GHz bands. You can also enable 2.4 GHz coverage throughout the deployment as a best practice to provide access for clients that use both bands.
Channel Availability
This table shows the number of channels available for the 5 GHz band in the US.
|
Channel Width |
Without DFS |
With DFS |
|---|---|---|
|
20 MHz |
9 |
25 |
|
40 MHz |
4 |
12 |
|
80 MHz |
2 |
6 |
|
160 or 80+80 MHz |
1 |
3 |
Most networks deploy 40 MHz or 80 MHz channels based on use case requirements and spectrum availability. Some notable exceptions are high density auditorium or stadium and arena deployments where it is often preferable to use 20 MHz channels because of the ability to reuse channels.
We recommend you consider the use of 80 MHz channel plans only if DFS channels are available, because without DFS channels only two non-overlapping 80 MHz channels are available. if you use DFS channels, you have six non-overlapping DFS channels available.
Channel Width
Wider channel widths such as 80 MHz and 160 MHz provide greater bandwidth and data rates compared to smaller channel widths (20 and 40 MHz), but this also means fewer channels are available and increases the possibility of co-channel interference in dense environments.
For example:
- 160 MHz — Only two channels are available
- 80 MHz — Provides 6 non-overlapping channels if DFS channels available
- 40 MHz — Provides 12 non-overlapping channels if DFS channels available
- 20 MHz — Many channels and combinations available
Channel width selection depends on several factors including use case requirements, spectrum availability, RF environment, and budget for the number of access points required. In a deployment in which you cannot use DFS channels (and must therefore use 40 Mhz channels), you might need to reconsider your requirements. For example, you might need to decrease the bit rate at which video is streamed for 2.4 GHz-only clients and for dual band clients that do not support DFS channels. Deploy 2.4 GHz throughout your network to provide some additional capacity.
In general, these channel widths are recommended:
- High density and non-DFS deployments — Use 20 or 40 MHz channels
- Low density and DFS channels available — Use 40 MHz channels
- Well-designed deployment with DFS channels available — 80 MHz channels
Channel Capacity Estimation
Capacity planning must be use-case specific and must consider these factors:
- Total active devices
- Types of devices
- Usage patterns
- Applications in use
- Area of coverage
Estimated throughput capacities for different channel widths and spatial streams are provided in this table:
| Spatial Streams | Maximum Data Rate per Channel Width | |||
|---|---|---|---|---|
| 20 MHz | 40 MHz | 80 MHz | 160 MHz | |
| 1 Spatial Stream | 87 Mbps | 200 Mbps | 433 Mbps | 867 Mbps |
| 2 Spatial Streams | 173 Mbps | 400 Mbps | 867 Mbps | 1.73 Gbps |
| 3 Spatial Streams | 289 Mbps | 600 Mbps | 1.33 Gbps | 2.34 Gbps |
| 4 Spatial Streams | 347 Mbps | 800 Mbps | 1.73 Gbps | 3.47 Gbps |
These rates are maximum data rates and not throughput capacity rates. Throughput capacity rates are much lower because of factors such as protocol overhead, contention loss, and loss due to signal strength degradation.