Large public venue

• 1: Network design fundamentals and criteria for large public venues
• 2: Radio frequency planning and channel optimization
• 3: Bandwidth planning and capacity calculations
• 4: Security practices and network protection for LPV
• 5: LPV calculator instructions

1 - Network design fundamentals and criteria for large public venues

This topic presumes the reader possesses an advanced knowledge level of Wi-Fi deployments and RF design. This guide aims to bring the most relevant design considerations and factors relevant to high-density and large public venues, either indoors or outdoors.

Some of the common, high-density design criteria for a wireless network design can be broken down into the metrics mentioned here. Designing a high-density wireless network must consider critical environmental and technical factors beyond just the seating capacity of the venue and an estimation of how many devices will need Wi-Fi connectivity.

The first couple of metrics are self explanatory and help the network planner achieve a rough estimate of AP count, but that does not provide the complete design or answer for all of the considerations that must be weighed for an LPV deployment.

There are several assumptions this guide and the online calculator make which might not align perfectly to the project you are pursuing. Based on the previously mentioned considerations, the following assumptions are listed:

Seating capacity

• HPE Aruba Networking recommends any venue with less than 10,000 users use an overhead mounting scheme.

• Venues large enough for more than 10,000 users may have a mixture of overhead and underseat access points. The LPV rough order of magnitude calculator will allow an engineer to choose between the two methodologies.

Take rate

• Due to the ubiquitous nature of Wi-Fi and smart devices, today’s take rate (total number of unique users) may range from 20% and 100% depending on the venue type and network usage expected.

• Remember that network utilization will grow over time and best to scope a venue based on the customer’s expected growth of function, utilization and ultimately usage 2-3 years into the future. Far better to err on the side of extra capacity than less.

Seats or areas covered per AP

• Based on experience, HPE Aruba Networking assumes that with an overhead mounting deployment in a large public venue, each AP radio will service up to 200 clients.

• If underseat AP placement is used, HPE Aruba Networking assumes 60 clients per radio for under seat AP placements.

• The online LPV ROM calculator uses these values as the default. The tool allows these variables to be changed based on the actual venue’s requirements.

Associated devices per radio

Determining the optimal number of devices per radio is crucial for maintaining network performance in high-density environments. While access points have maximum association limits, effective design requires operating well below these thresholds.

• Underseat placement - design for the actual seat count covered by each AP.
• Overhead placement - design for ~150 devices per radio based on expected take rate.

Understanding these design parameters allows you to calculate realistic association expectations and properly size the network infrastructure for sustained performance under actual operating conditions.

Underseat placement

For underseat placement, design for 100% take rate of the seats covered by each AP radio. The number of expected clients per radio should match the seat count per AP. For example, if the design covers 60 seats per AP, plan for 60 clients per AP radio.

Overhead placement

Overhead mounted access points typically cover larger areas than underseat deployments. Each overhead AP generally serves 150-200 seats, but client associations are calculated based on expected take rate rather than the total seat count the AP covers. The actual number of connected devices will depend on venue type and user behavior patterns, where ~150 active associations per radio is a starting point in the design.

Radio type

• Due to current bifurcation of 6 GHz regulatory adoption at the time of writing between 500 MHz or 1200 MHz decisions, 6 GHz radio usage in LPV will only be applied to countries with 1200 MHz of unlicensed frequency for 6 GHz use.

• All other regions will default to 5 GHz radio usage for LPV.

Gateways

Several factors will dictate whether gateways will be used or not. The key deciding factors for gateways/controllers are:

• Any solution designed with an AOS-8 architecture.

• Any solution involving Dynamic Segmentation.

• In the case of an AOS-10 based network architecture, any solution with more than 500 Access Points or more than 5000 clients, whichever comes first.

To simplify design decisions and maximize the performance, HPE Aruba Networking recommends the 9240 Gateway model be used. This provides HPE Aruba Networking’s most powerful hardware gateway and can provide throughput and connectivity options that any large venue may require.

Gateways can be clustered together to provide additional capacity and redundancy. Cluster sizes can vary from a 6-node cluster with AOS-10 or clusters with up to 12 nodes when utilizing AOS-8.

This scaling is very important and can be further simplified by stating that at least one pair of HPE Aruba Networking 9240 gateways be used per 32,000 devices.

As a best practice, network capacity should be engineered to 80% of maximum limits to provide adequate headroom for traffic spikes, device growth, and optimal performance under real-world conditions.

Refer to the Validated Solution Guide (VSG) capacity planning for sizing and planning of gateways at scale.

Access points and antennas

Based on HPE Aruba Networking’s experience in real-world, large public venues hosting thousands of concurrent users, this guide and the online LPV ROM calculator tool default to a number of Access Points from the AP-5xx/AP-6xx/AP-7xx series, based on venue location and area being served.

As previously stated, based on 6 GHz adoption, all US Deployments will default to 6 GHz capable access points. Because of the nature of 6 GHz this eliminates having to worry about backwards compatibility or legacy devices, further simplifying design considerations.

HPE Aruba Networking recommends using directional antennas where possible, to focus coverage on high-density areas, to improve signal quality and reduce interference.

United States deployments

• If indoors, with underseat placement, AP-6xx series Access Points will be used in conjunction with external antennas, specifically AP-ANT-312 antennas.

• If indoors, mounted overhead, the AP-679 model will be used with integrated antennas allowing for both narrow and wide antenna patterns.

• If outdoors, with underseat placement, the AP-654 with AP-ANT-312 external antennas will be used.

• If outdoors, mounted overhead, then AP-679 with integrated directional antennas will be used.

• Suites and concession stands typically require an AP per location, the AP-635 will be the default selection for these types of areas. These are presumed to provide either overhead or side coverage.

• Gates in to and out of the venue are often high-density locations in and of themselves. In these cases, an overhead mounted AP-677 will be suggested by default.

For all other Rest of World Deployments, 5 GHz radios will be used by default due to current adoption and ratification rates for 6 GHz usage. As adoption and ratification increases, the calculator can be modified to reflect these new opportunities to deploy in 6 GHz.

Rest of world deployments

• Indoor, underseat, external antennas, AP-5xx series with AP-ANT-312.

• Indoor, overhead, external antennas, AP-574 with AP-ANT-5314.

• Outdoor, underseat, external antennas, AP-518 with AP-ANT-312.

• Outdoor, overhead, external antennas, AP-574 with AP-ANT-5314.

• Suites and concession stands require an AP per location, an AP-5xx series access point will be the default selection for these types of areas. These are presumed to provide either overhead or side coverage.

• Gates in to and out of the venue are often high-density locations in and of themselves. In these cases, an overhead mounted AP-577 will be suggested by default.

Use of AP-6xx series access points and 6 GHz frequencies in rest of the world deployments must follow the target country’s respective 6 GHz outdoor regulations.

Type of venue

Another key consideration will be the type of venue. Based on the venue, areas, expected traffic flow, capacity, and expected usage.

Common venues

Common examples of high-density, large public venues include the following:

• Large meeting rooms

• Lecture halls and auditoriums

• Convention center meeting halls

• Hotel ballrooms

• Stadiums, arenas, and ballparks

• Concert halls and amphitheaters

• Casinos

• Airport concourses

• Passenger aircraft and cruise ships

• Places of worship

• Financial trading floors

Each example includes some common design criteria as well as unique challenges and considerations.

• Venue layout - document the physical and architectural characteristics of the venue, which can impact signal propagation.

• User density and distribution - understand how users are distributed across the venue, as density impacts interference and capacity needs. What is the anticipated user flow through the venue? Certain areas may need more or less coverage and capacity depending on how users are expected to flow through the area.

• Assess network infrastructure - routing/switching architecture, system services, for example the venue’s internet connection, MAC/ARP limitations, DHCP/DNS performance, etc.

• Real-world factors - adjust for real-world factors such as signal quality, interference, and user movement. Typically, real-world throughput is about 50-70% of theoretical maximums. Also consider protocol overheads from operations like MAC layer acknowledgments and beacon transmissions.

• Environmental overheads - account for additional environmental factors like RF noise and non-Wi-Fi interference that may impact performance.

• High-density areas should never be designed for peak single-client burst rate. VHD areas are designed to provide a low, common throughput like 1 Mbps or 4 Mbps to all clients. While occasionally possible to hit the peak if the network is not busy, the baseline assumption for any high-density network is that the channel is very congested and average device throughput is much lower than the peak rate.

• Use 20 MHz channel widths as the baseline configuration. 40 MHz channels should only be considered in certain advanced situations which are out of scope for this page. This narrower channel width brings down the peak data rate dramatically (from 780 Mbps to just 86.7 Mbps for a typical 1SS 802.11ac smartphone).

• Most client devices are only 1 SS or 2 SS capable, and many will operate at 1 SS when the battery is low to conserve battery life. This is expected across modern devices due to physical size and battery power constraints.

Venues with a movable roof

While stadiums with roofs that open and close can introduce some complexities, a robust and flexible Wi-Fi solution that maximizes the 6 GHz band advantages can still be achieved by factoring in a few key considerations:

• Position APs and antennas strategically to account for the changing environment when the roof opens or closes. Consider that the roof position will affect signal propagation and reflection.

• Understand that opening the roof changes the RF environment significantly. Have strategies in place to deal with signal diffraction and attenuations when the roof is closed.

• Evaluate how different roofing materials, both in open and closed positions, impact RF signals. Metal or concrete structures could reflect or absorb 6 GHz signals.

• Implement infrastructure that can withstand any vibrations or movements caused by the mechanism opening and closing the roof.

• Apply dynamic frequency selection to adapt to potential changes in interference patterns caused by the transient nature of the stadium’s roof.

• Design network plans that minimize interference from other sources, including cellular networks or microwave links.

• Plan for seamless handover and transition between APs as users move into areas with differing roof statuses (open vs. closed), ensuring consistent high-quality connectivity.

• Utilize wider channel availability in 6 GHz to support more users and high-bandwidth applications.

2 - Radio frequency planning and channel optimization

The frequency band utilized will directly affect the total system throughput (TST) based on the number of available channels in each country based on that country’s regulatory adoption of the band.

While the 2.4 GHz band has been approved for use in most countries, the number of non-overlapping channels in this band makes 2.4 GHz unusable for LPV deployments. 2.4 GHz is not taken into consideration for any LPV planning.

Most HPE Aruba Networking access points include a 2.4 GHz radio but this radio is recommended to be disabled for client usage in large public venue deployments due to insufficient non-overlapping channels for high-density environments. While the 2.4 GHz band may optionally be repurposed for specialized applications like IoT devices or handheld scanners in targeted areas, 2.4 GHz should remain disabled for general client access. Legacy 2.4 GHz-only clients should be decommissioned in favor of 5 GHz-capable devices.

Customers should look to leverage both the 5 GHz and 6 GHz bands to increase capacity. The 5 GHz band offers more non-overlapping channels than 2.4 GHz, and 6 GHz provides even more, reducing interference and allowing more simultaneous connections.

Today’s current state of technology is based on Wi-Fi 7. The latest 802.11be standard builds upon the previous standard of 802.11ax and can operate across the 2.4 GHz, 5 GHz, and 6 GHz frequency bands.

Using 5 GHz

Available since the release of 802.11a in 1999, 5 GHz became widely adopted around the world. This band can now provide up to 28 non-overlapping 20 MHz wide channels, when including U-NII-4.

Using 6 GHz

6 GHz capable access points provide significantly increased capacity and with the 6 GHz band can handle more devices simultaneously without sacrificing performance, making them perfect for very high-density environments like conference centers, stadiums, and other public venues.

Wi-Fi 6, Wi-Fi 6E, or Wi-Fi 7 access points benefit from higher data rates, improved efficiency, and reduced latency. Wi-Fi 6E extends these benefits into the 6 GHz spectrum, offering more channels and less congestion. Wi-Fi 7 can also leverage 6 GHz.

Previously unused, the 6 GHz frequency range offers a vast amount of clean, uncongested spectrum. This means more bandwidth, less interference, and lower latency leading to significantly faster speeds and more reliable connections.

6 GHz offers wider channels, up to 320 MHz are possible and can deliver multi-gigabit speeds in a single collision domain with no overlap from other Basic Service Sets. In the LPV setting, there will be many Basic Service Sets using the same collision domain preventing scaling out and deploying wider channel widths.

This means optimizing Wi-Fi performance for tens of thousands of users in a large public venue requires careful balancing of throughput, capacity, and interference when selecting channel widths from 20 MHz to 320 MHz.

Channel width

5 GHz

Channels can be bonded together to increase the channel bandwidth, but historically any LPV deployment should use 20 MHz channels. This includes any deployment with more than 14 access points in a single area. The primary goal is to provide clients with separate collision domains to improve performance and user experience in the LPV setting.

6 GHz

Channel width selection depends on multiple deployment specific factors requiring careful evaluation at each implementation. Use appropriate channel widths (20, 40, 80, 160 or 320 MHz) based on the specific use case, AP density, regulatory constraints, and available spectrum of the environment to balance increased throughput with potential interference.

Careful consideration of the expected use of the network will help influence this design decision. Some main points to consider are listed below.

Utilizing narrower channels can minimize interference from overlapping channels, thus enhancing overall network stability and performance. While having more channels helps with capacity, each individual channel provides lower throughput compared to wider options, which might not be ideal for high-bandwidth applications.

In general, bonded channels should not be used in high-density areas such as large public venues.

Take for example a large public venue with over 50,000 visitors, 20 MHz non-overlapping channels at 6 GHz are significantly better than 80 MHz bonded channels because.

• Capacity and density - the primary challenge in such a dense environment is user density, not necessarily raw speed for individual users. 20 MHz channels allow you to serve many more concurrent users. Think of this like lanes on a highway. More, narrower lanes (20 MHz) allow more cars (users) to travel simultaneously than fewer, wider lanes (80 MHz), even if the wider lanes technically allow for faster speeds. With 50,000+ users, maximizing the number of simultaneous connections is crucial.

• Interference mitigation - in a crowded 6 GHz spectrum, interference is a significant concern. 20 MHz channels are less susceptible to interference than 80 MHz channels. A narrower channel is less likely to be impacted by adjacent channel interference or other radio frequency noise. With 80 MHz channels, a single interfering signal can disrupt a much larger chunk of the spectrum, impacting more users.

• Reduced channel contention - with more, narrower channels, the likelihood of channel contention (multiple devices trying to use the same channel simultaneously) is reduced. This translates to a smoother, more reliable experience for users.

• Simplified network management - managing a network with numerous 20 MHz channels is generally easier than managing a smaller number of wider channels, especially in a dense environment. It provides more granular control and flexibility for network optimization.

• Lower latency - while 80 MHz could offer lower latency under ideal conditions, in a real-world, high-density scenario, the increased contention and interference are likely to result in higher latency for many users. 20 MHz channels, while not as fast individually, would likely provide a more consistent and lower latency experience for the majority of users due to less congestion.

40 MHz channels represent a middle ground between 20 MHz and 80 MHz, and while they might seem like a compromise, they are still less suitable than 20 MHz channels for a large public venue with 50,000+ simultaneous users.

Consider the following:

• Capacity still a concern - while using 40 MHz channels offers more capacity than 80 MHz, they still provide less capacity than 20 MHz channels. In a venue with such a high user density, maximizing the number of concurrent connections remains the top priority. 40 MHz channels simply don’t offer enough “lanes” on the Wi-Fi highway to handle that many users efficiently.

• Increased interference risk - 40 MHz channels are still more susceptible to interference than 20 MHz channels. In a crowded 6 GHz spectrum, this increased risk can lead to performance degradation and dropped connections for a significant number of users.

• Device compatibility - while more 6 GHz devices will likely support 40 MHz than 80 MHz, there might still be some devices that only support 20 MHz. Sticking with 20 MHz ensures the widest possible compatibility and allows the maximum number of users to connect.

• Diminishing returns - while 40 MHz offers a theoretical speed increase over 20 MHz, the real-world benefit in a dense environment is likely to be minimal. The increased contention and interference will likely negate any potential speed gains, and may even result in lower overall performance for many users.

• Network management complexity - managing a network with a mix of 20 MHz and 40 MHz channels can add complexity to network planning and optimization, especially in a large venue. Sticking with a consistent channel width (20 MHz) simplifies management and allows for more predictable performance.

Additional considerations:

• Increased reuse distance - Using 80 MHz or 40 MHz channels reduces the number of radio channels by bonding them together.

• Thermal noise floor increases by 3 dB with each doubling of channel width. This means higher SINRs - 20 MHz channels experience up to 6 dB more SINR than 80 MHz channels for the same data rate, and up to 3 dB more SINR than 40 MHz channels.

• Higher performance - distributing 25 users each across four different 20 MHz channels delivers better results than placing 100 users on a single 80 MHz channel.

In a large public venue with 50,000+ users, prioritizing capacity and reliability over raw speed is paramount. 20 MHz channels offer the best balance of these factors, ensuring a usable and consistent Wi-Fi experience for the vast majority of visitors. While 80 MHz might seem attractive on paper, this approach is simply not practical or scalable for such a dense user base.

40 MHz channels might seem like a good compromise, they ultimately fall short of meeting the demands of such a large public venue with 50,000+ users. Again, the priority in such an environment is maximizing capacity and ensuring reliable connectivity for the majority of users. 20 MHz channels remain the most effective solution for achieving this goal.

Spatial efficiency is critical. When large numbers of users are present, optimizing channel utilization and providing the most dense coverage as possible, requires the solution architect to consider small channel sizes.

HPE Aruba Networking recommends not to use bonded channels in high-density areas unless the anticipated network and channel reuse dictates use.

Recommendations

Given the scenario of a large public venue with 50,000 users, choosing the correct channel width depends on usage patterns and network goals:

• Opt for 40 MHz channels if the focus is on maximizing throughput for fewer but bandwidth-intensive applications. 40 MHz is ideal where high-speed internet access for streaming and media-rich applications is critical, and the network can be managed to limit interference. However, we cannot opt for 40 MHz because the capacity is too high for effective channel reuse at 40 MHz channel width. Careful consideration, at a smaller venue size than the scenario, could be performed to evaluate if 40 MHz channel width is feasible. Please contact your account team for a more in depth conversation about this topic.

• Opt for 20 MHz channels since the aim is to maximize user capacity and ensure robust connectivity across a highly dense user base, reducing interference and improving overall user density management. This setup can better handle a large number of devices performing less data-intensive activities, like browsing and social media usage.

A hybrid approach may be most effective, dynamically adjusting channel width based on coverage area type, user distribution, usage patterns, and real-time network conditions. However, the network design must maintain consistent channel widths across the ESS. Inconsistent channel widths cause clients to prefer BSSes with wider channels over those with better signal quality, as channel width ranks higher in BSS selection criteria than signal strength.

Different areas of a large public venue cam vary greatly in the coverage and capacity required. Ticketing areas, gates, concessions, concourses and bowl areas all have different requirements. Advanced network management tools and careful planning can optimize channel utilization effectively in such a large venue.

Channel plans

All channel plans can be categorized according to three criteria.

1. Dynamic vs. static

   • A dynamic channel plan is one that can change in response to external events, such as interference or system load.
   • In a static channel plan, the channel numbers are fixed and should not change.

2. Global vs. local

   • A global channel plan uses the same channel list for all APs that terminate on the system.
   • A local channel plan uses different channel lists for different groups of APs on the same system.

3. Repeating vs. non-repeating

   • A channel plan is repeating if the same channel number is used more than once in the same coverage area.
   • A channel plan is non-repeating if the same channel number cannot be reused in the same coverage area.

Most indoor WLANs are dynamic, global, and repeating.

Typical examples for high-density.

• Global and non-repeating

  • University building with multiple adjacent lecture halls, with all channels available but no individual lecture hall can use the same channel more than once. Could be static or dynamic depending on exact configuration method used.

• Local and repeating

  • Outdoor stadium with the bowl area using outdoor-only channels and the suites and concourses using indoor-only channels.

  • Large arena bowl area with fixed channel assignments that uses DFS channels for capacity, while only non-DFS channels are in use in other parts of the facility.

• Static, local, non-repeating

  • A concert hall with two dedicated ticketing APs at entry gates on channels 36 and 149. Every gate features an identical setup.

  • Stadium press box with four dedicated APs that are hard-coded to channels that cannot be used in the bowl seating area.

  • A convention center with a “house” channel dedicated to presenters that exists on one AP in the front of every individual meeting room (and nowhere else).

• Dynamic, global, non-repeating

  • A press area with six APs that can use any channel but no channel can be used more than once.

Coverage strategies

Additional assumptions will be made based on the coverage strategy used. As stated, this guide and the online LPV rough order of magnitude calculator tool only accounts for overhead or underseat deployments. However, due to the variations of large public venues, certain considerations must be made. Each area of the LPV must be assessed individually and only one coverage strategy per area is recommended.

There is adjacent channel interference (ACI) and co-channel interference (CCI) in virtually every high-density deployment. So long as minimum separation distances are observed, ACI can be safely ignored in most high-density areas of 10,000 seats or less.

Remember that AP to AP spacing when using directional antennas, the AP’s should be no closer than 2 meters or 6.5 feet. Access Points utilizing integrated antennas should be spaced never less than 5 meters or 16 feet apart.

Overhead coverage

Side coverage

Floor coverage

Additional coverage considerations

• Venue design - the physical layout and construction materials of the venue can influence which approach is more effective.

• User density and behavior - high user density can favor underseat installations due to their ability to minimize interference, whereas overhead APs might be superior in less dense scenarios.

• Cost and scalability - underseat solutions can be more costly due to the number of APs required and installation complexity but might provide superior service in capacity-demanding environments.

• Temporary deployments - underseat placement can be used more readily in temporary coverage areas versus mounting Access Points overhead.

• Future-proofing - overhead solutions might more easily accommodate the integration of future technology updates with less disruption.

In general, the decision between overhead and underseat APs should be tailored to the specific requirements and conditions of the venue. In many cases, a hybrid approach leveraging both methods in strategic locations can provide the most robust and comprehensive coverage, balancing coverage quality and capacity while considering installation and maintenance logistics.

Overhead coverage

• Overhead coverage is a good choice when uniform signal is desired everywhere in the area.

• APs with integrated antennas may be used when the area’s ceilings are less than 10 meters or 33 feet high. For open spaces with minimal signal attenuation, consider integrated directional antennas for better control of signal propagation.

• If the ceilings are higher than 15 meters/50 feet use of external antennas should be used. If questions persist, consult with your account team for further consultation.

• No RF spatial reuse is possible with overhead coverage because of the wide antenna pattern and multipath reflections.

• In multi-floor venues, stagger the Access Points in each room underneath and do not place access points directly above one another.

• Floors generally absorb more RF energy than walls (10-15 dB is a typical range).

Advantages:

• Line-of-sight coverage - overhead mounting typically ensures better line-of-sight to users, reducing signal obstructions such as furniture or people.

• Wider coverage area - generally provides a broader coverage area, making overhead coverage more effective for covering large open spaces.

• Reduced physical interference - less likely to be blocked by objects or people, which can be particularly advantageous when utilizing higher frequency bands like 5 GHz and 6 GHz.

• Reduced reflection - higher placement can help minimize signal reflection and refraction that are common when signals interact with fixtures, furniture, or people, which is a significant consideration at higher frequencies due to their limited penetration abilities.

• Easier maintenance access - easier to access for maintenance and upgrades without interfering with seating or crowd movement.

Disadvantages:

• Potential for higher contention - if not adequately planned, can lead to more overlapping coverage areas, which can increase contention and interference.

• Installation complexity - may require complex installations in venues with high ceilings or other architectural constraints.

Side coverage

• Wall, beam, and column installations with side-facing coverage are very common in high-density areas.

• To reduce both Adjacent Channel Interference (ACI) as well as Co-Channel Interference (CCI), mount all the AP’s on one wall facing the same direction.

• Signal bleed outside of the desired coverage area is wasted as compared to overhead coverage.

• When mounting back-to-back, ensure proper channel separation to avoid interference. For access points configured with 20 MHz channel width, maintain a minimum of 40 MHz separation between radio channels. For example, use channels 36 and 44 rather than 36 and 36 or 36 and 40.

• Signal levels will be lower in the center of the room than on the sides.

Underseat coverage

• Should be used high-density areas with more than 10,000 seats.

• Underseat places APs create Picocells and that allows for a much higher radio density compared to overhead or side coverage schemes.

• Picocell designs leverage the natural human body loss that occurs to RF signals as they pass through a crowd (also known as “crowd loss” or “crowd effect”).

• Significant increases in total system throughput are possible because of increased RF spatial reuse.

• Because higher AP densities can be achieved, cell sizes can be as small as between 60-75 seats. This guide and the online LPV rough order of magnitude calculator use a default of 60 seats for underseat designs.

• APs should be evenly distributed and spaced to provide more uniform signal coverage in the area. Strive to make AP-to-AP distances as equal as possible.

• Minimum AP-to-AP spacing should never be less than 2 m (6.5 ft) when using external directional antennas.

• Minimum AP-to-AP spacing should never be less than 5 m (16 ft) when using integrated antennas.

Advantages:

• Proximity to users - placement nearer to users can enhance the quality of the connection due to reduced signal path length and attenuation.

• Reduced Co-Channel interference (CCI) - signal is more contained and less likely to interfere with surrounding cells, effectively compartmentalizing coverage.

• Targeted coverage - ideal for environments where the seating arrangement is fixed and dense, allowing for precise coverage planning.

Disadvantages:

• Physical obstructions - signals can be impeded by human bodies, furnishings, and other physical barriers, especially detrimental for higher frequency bands.

• Maintenance Challenges - harder to access for repairs or upgrades, as these might disrupt seating arrangements or require special scheduling during unoccupied times.

• Smaller cell size - each AP typically covers a smaller area, requiring careful planning to ensure comprehensive coverage without gaps.

3 - Bandwidth planning and capacity calculations

One of the key success criteria of a high performance, Wi-Fi network is the expected system performance and amount of bandwidth available to users and applications.

Number of access points

Once considered, a simple formula can help you estimate the number of access points required for a high-density deployment:

$AP\ count = 5/6\ GHz\ radio\ count = \displaystyle\frac{Associated\ device\ capacity\ (5/6\ GHz)}{Max\ associations\ per\ radio}$

In this example, you can simply calculate how many radios of a certain type will be required. Max associations per radio as stated earlier calculated at 60 users per radio for underseat placement of the access point or if mounted overhead, one radio per 200 clients.

Number of clients per access point

Clients per access point are both a design decision as well as a hardware limitation. While the following values represent maximum client association counts for certain platforms, designs should target significantly lower client counts to ensure optimal performance and user experience. You must always check the product data sheet to verify what the maximum allowed associations is per radio.

• AP-67x - max 512 associated client devices per radio (1024 total)

• AP-654 - max 1024 associated client devices per radio (2048 total)

• AP-518 - max 512 associated client devices per radio (1024 total)

• AP-574 - max 512 associated client devices per radio (1024 total)

• AP-635 - max 512 associated client devices per radio (1024 total)

The online LPV rough order of magnitude calculator by default calculates 60 client devices per radio when placed underseat and 200 client devices per radio when mounted overhead. These numbers can be tailored to the venue’s density requirements.

Bandwidth per client

Calculating the bandwidth per client is simply a matter of taking the channel’s available bandwidth and dividing by the anticipated number of clients per radio/channel.

This is not a perfect calculation and doesn’t take into account any of the real world conditions such as interference, congestion, distance, channel width, etc and one can easily take approximately 25% off that total because of lost airtime due to the nature of Wi-Fi communications. HPE Aruba Networks uses the term “Goodput” to define the actual amount of useable bandwidth minus the overhead, protocol limitations, and other factors like distance that can reduce the actual usable throughput.

Setting realistic expectations about Wi-Fi speeds is important - focus on whether the solution will provide a useable experience for the venue’s needs rather than theoretical numbers.

Associated device capacity

The associated device capacity (ADC) count and associated device per radio count are more important factors than bandwidth per client in designing a high-performance, high-density WLAN which meets the customers demands today and throughout the expected service life of the network. Depending on the type of venue, associated device capacity will vary. For example, a university lecture hall may have close to a 100% take rate versus a concert hall may have less than a 25% take rate.

This formula may provide a rough AP count, but will not guarantee a high-performance, high-density wireless LAN. This AP count still is not considering key performance metrics such as per-user bandwidth requirements or radio cell size. These two metrics can increase the number of access points truly required to deliver the correct design for the customer’s requirements.

In fact, high-density WLAN in large public venues must be designed with growth in mind. A high-density WLAN should be designed knowing that adoption increases over time and that the Associated Device Capacity number impacts much more than just the number of radios needed for a given band, but also all the upstream network infrastructure that will be required such as address space, ARP cache size, forwarding/bridge table size, DHCP lease binding database size, firewall sessions, public IP addresses for NAT/PAT, captive portal sessions, system licenses, HA dimensioning, and so on.

Other criteria such as the maximum associated devices on a particular radio can vary based on the model access point chosen.

Computing the total system throughput for a Wi-Fi network involves multiple considerations, including the Wi-Fi technology in use, the spectrum available, the environment, and user behavior. There are two main throughput numbers to be concerned with, Per AP Throughput and the Aggregate throughput across all APs.

To calculate a Per AP throughput, simply multiply the estimated per-client throughput by the number of supported users per AP. This can vary by AP Model and can be verified by checking the device’s datasheet.

Total system throughput

The basic mathematical formula to compute the aggregate throughput or the total system throughput is as follows:

$\displaystyle{Total\ system\ throughput\ (TST) = Channels \times Average\ channel\ throughput \times Reuse\ factor}$

Where:

• Channels = Number of channels in use by the high-density network.

• Average Channel Throughput = Weighted average goodput that is achievable in one channel by the expected mix of devices for that specific facility.

• Reuse Factor = Number of RF spatial reuses possible. For all but the most exotic high-density networks, this is equal to 1, which means no RF spatial reuse.

• Assume a 5 GHz deployment with 9 channels, an average channel throughput of 50 Mbps, and no RF spatial reuse, the TST would be 450 Mbps: $9\ Channels \times 50\ Mbps \times 1\ Reuse = 450\ Mbps$.

Additional channel throughput considerations

• Channel throughput depends heavily on the number of stations that attempt to use the channel simultaneously.

• Collisions and MAC-layer inefficiencies reduce overall capacity as more and more devices contend (compete) for medium access.

• Single-client throughput represents peak goodput performance measured during a speed test on a clean channel without other users present.

• Multi-client throughput is the weighted average goodput that is achievable in one channel by the expected mix of devices in a particular high-density area.

• Channel throughput can be further reduced by many impairments including misbehaving client devices, CCI, ACI and non-Wi-Fi interference.

• Real-world environments are rarely so pristine.

Another example calculation

Assume each access point can effectively deliver 100 Mbps of real-world throughput and support 50 users efficiently.

If 1,000 APs are deployed strategically throughout the venue:

• Each AP can support 100 Mbps.

• Total throughput for all APs is $1,000\ APs \times 100\ Mbps/AP = 100,000\ Mbps\ or\ 100\ Gbps$.

Then for each AP supporting 50 users:

• User throughput equals $100\ Mbps \div 50\ users = 2\ Mbps/user$.

4 - Security practices and network protection for LPV

Large public venues which offer open guest networks in high-density areas are natural targets for casual and malevolent hackers. This list of network hardening options is considered a best practices and is recommended:

• If possible, do not configure a Layer 3 interface on wireless user subnets (including secure subnets) unless a captive portal is being used and redirect is required. The gateway or controller should be Layer 2 only on all wireless subnets into which users can be placed.

• Do not configure the gateway or controller to be the default gateway for any user subnet.

• Place the DHCP server on a Layer 3 separated subnet and use DHCP relay.

• Avoid configuring the gateway or controller as the DHCP relay for any user subnet.

• Configure the validuser ACL to allow the configured and known user subnets, and disallow those IP addresses or IP address ranges that should be protected such as default gateways for each subnet, DNS, DHCP, captive portal, etc.

• The guest role should explicitly disallow connection to network infrastructure elements via TCP ports 22 and 4343.

• The guest role should explicitly disallow telnet, SSH, and other protocols that are not required for guest services.

• Enable ARP spoof prevention on the default gateway for wireless user subnets and also on the controller if there is an L3 address on any wireless user VLANs.

• Use a dedicated infrastructure subnet to connect all Wi-Fi gateways or controllers, APs, and servers.

• Use ClearPass for administrator authentication using RADIUS and/or TACACS. Monitor the logs.

• Use an IDS solution to monitor infrastructure and user subnets for suspicious activity.

• Shutdown all unused Ethernet interfaces on the gateway/controller.

• Monitor for rogue and potential rogue devices in Central and on the gateway or controller.

• Enable “enforce-dhcp” in AAA profiles to prevent users from being able to assign static addresses and gain access to disallowed networks or spoof network resources.

5 - LPV calculator instructions

Designed to assist with the effort for generating a rough order of magnitude (ROM) design, the LPV ROM calculator utilizes the assumptions in the previous pages along with the LPV team’s years of experience and best practices to generate a bill of materials that can be used for ROM purposes.

Getting started

The first question is the country where the LPV resides. This helps the calculator by determining the primary radio to be used at the venue. This will also help compute the venue’s total system throughput.

The ROM calculator takes all of the previous design criteria mentioned and default assumptions into consideration. As there are a variety of large public venues with various density requirements, the tool allows for key assumptions to be modified.

The country determines which frequency band to use. When the United States is chosen, the calculator will provide a solution set based on 6 GHz. If Rest of World is selected, the calculator will default to the 5 GHz band.

Coverage strategy

The key determining factor in coverage strategy to be used is the expected take rate of visitors and their devices. Venues with less than 10,000 seats are recommended to use an overhead coverage strategy. The reasons and concerns were specified previously.

Venues with more than 10,000 seats may incorporate a variety of coverage strategies depending on the number and types of areas the venue may contain. The calculator will allow modeling of both overhead and underseat coverage of an LPV and also a mixed environment in the case of a more complicated venue layout. Implementing an underseat coverage strategy, the LPV ROM calculator will initially target 60 seats per radio. Overhead coverage strategies assume a default of 200 seats to be covered per radio.

These default values and other calculator defaults can be changed under the Advanced Deployment Options.

Here the number of clients/seats can be modified to reflect the number of seats to that will be planned for either overhead or underseat coverage.

Other advanced options include the maximum number of clients per controller or gateway, the maximum number of access points per switch, and switch capacity preference. Due to maximum Ethernet cable lengths most LPV environments will typically connect no more than 20 access points to a single switch. Also, depending on the expected usage of the area, more or less wired ports may need to be provided possibly for kiosks or other types of device access. To allow for further flexibility in the deployment the calculator allows for the selection between 24 and 48 port access switches.

The calculator will suggest either a 24 port or 48 port HPE Aruba Networking 6300M switch.

Additional coverage requirements

Large public venues often have areas which require different amounts of Wi-Fi network capacity and may require different coverage strategies to serve them. Examples of areas requiring special handling include:

• Entrance gates, usually exhibit a predictable and very high flow of traffic as visitors enter and then traverse the venue.

• Suites, common to sporting arenas and some other venues, require special handling as the suites could be reserved for corporate or private customers.

• Press or broadcast booths, quite often require dedicated planning to handle the potential higher network usage from people in the area.

• Concession areas which are often dispersed throughout large public venues. Typically found outside of the main event or bowl area of the venue and may require additional consideration.

Depending on the venue type, areas designated for purposes like event registration or event support could be calculated as a suite or gate with the online calculator.

To simplify design considerations, these areas default to a single AP per area. The calculator allows planning for a set number of each type of area, adding the additional access points to the estimate. If density requirements dictate more than a single AP in any one of the areas, make sure to adjust the number entered accordingly.

All additional gate, suite, or concession areas, regardless of region, will default to either the AP-635 or AP-677.

Example output

Here is the calculator output from a large public venue modeled on the following criteria:

• Country: United States
• Coverage strategy: underseat & overhead
• Underseat seating capacity: 50,000
• Overhead capacity: 2,500
• Number of gates: 8
• Number of suites: 24
• Number of concessions: 40

The calculator provides a reasonable, rough order of magnitude of the size of this example LPV project and can provide sufficient information to answer some of the initial questions that may arise.