Why organizing your APs in your network is important.
May 1, 2024
This entry we will dive a little deeper into WiFi to look at the nuances of organizing your WiFi Access Points (APs) appropriately. It is becoming more common to see a mix of WiFi standards (802.11n/ac/ax) in a single network environment. Be it due to availability of equipment, budgets, or resources, operating a mixed environment is becoming the norm.
Why should you group your APs by standard? They will work just fine in one single group – and it is easier to deploy and manage.
While this is true, there are nuances that will slowly erode and reduce the quality and efficiency of your WiFi over time. WiFi is a significant investment – shouldn’t you get the most from it?
Here are a few pitfalls of not organizing or grouping your APs properly.
- Firmware mismatches between APs of different standards/capabilities may cause service and/or connectivity issues.
- Inconsistent quality and connection experiences by the users/clients as they switch between different APs (capabilities of 802.11n is different from 802.11ax).
- Regulatory compliance requirements (indoor verses outdoor APs).
- Group APs with the same standard/capabilities (all 802.11ac APs) in the same wireless groups as well as physical locations within your network. This allows you to take advantage of enhanced features and capabilities in the APs to ensure a more consistent service for the clients.
- Grouping allows you to provide different WiFi Networks (SSIDs) to different areas. E.g. the scanner gun SSID is only available in the warehouse while the Visitor SSID is available in the office areas. You can still have a wireless network SSID that exists in all AP groups for full and seamless coverage.
- Grouping allows you to upgrade you APs (e.g. firmware updates) in smaller batches, reducing the impact and risk on your network.
- Assist in identifying and resolving WiFi and network related issues as they arise.
Making WiFi better, one network at a time.
Back to Top
Know Your (Wi-Fi) Clients
June 6, 2024
As engineers and designers of Wi-Fi networks, we spend a lot of time thinking about how the Wi-Fi works and behaves from a network perspective. We often overlook the other important variable in Wi-Fi – the client devices. These can be anything from your laptop, tablet and smart phone to wearables, gaming systems, and the multitude of IoT devices.
A Wi-Fi network is only as good as the Wi-Fi client’s ability to connect and use the Wi-Fi service. You can have the latest and greatest Wi-Fi Access Points and systems, but if your client devices cannot connect and use the Wi-Fi as they need to – all of that does not matter.
Identifying and knowing the actual capabilities of your Wi-Fi clients is critical to determining how you will configure and manage your Wi-Fi network. Do your Wi-Fi clients support the latest Wi-Fi standards? Do they support fast roaming? What is their transmit power range? The rule of thumb is to identify your least capable but most important (LCMI) Wi-Fi device, and build your Wi-Fi network service around that.
All these details will factor into how you should design, configure, and manage your Wi-Fi service. Designing around the clients – and not the technology – provides the greatest returns.
Making Wi-Fi better one network at a time.
Back to Top
Are you WiFi6E / 7 ready?
July 26, 2024
Researching, testing, and implementing the latest technologies is normal operation for us in the IT world. One of the main reasons (or concerns) for deploying new tech is our ability to understand, manage, and support it.
It takes time and practice to be able to assess, diagnose, and mitigate WiFi issues in 2.4GHz and 5GHz. With 6GHz you have new parameters, security features, and encryption methods to contend with.
First and foremost, you need to align the technology with your needs and device capabilities. Considering WiFi6E/7 is really about your ability to use the 6GHz band.
- What client devices can or will use 6GHz and where?
- Will 6GHz be on its own SSID or will it be shared across the WiFi bands (2.4/5/6GHz)?
- Will WPA2/WPA3 mixed mode encryption be used (for backwards compatibility to older devices) or will WPA3 be implemented for all devices?
- How will 6GHz impact WiFi roaming across the entire network?
- Do you need to support low latency applications and services (VoIP, real time streaming, etc)?
Next, how can you take advantage of WiFi6E/7 in supporting and managing your network?
Tools and systems provided by WiFi vendors will play an important role in this decision. Traditional vendors like Cisco/Meraki, Aruba, Ruckus, Extreme have mature tools and applications for supporting their equipment and features. New contenders like Cambium, EnGenius, and TP-Link are quickly catching up with their own capabilities.
More than just the upfront price, you need to consider the long-term effort in supporting and managing your WiFi network. Do you have the staff, skills, and time to spend on WiFi management? If not, what investment do you need to make to upgrade your team? More expensive equipment may have lower operational costs over time due to the ease of use. Lower cost equipment may have higher operational costs due to lack of tools and features. Weigh all these considerations in making the decision towards your move to WiFi6E/7.
Making WiFi better one network at a time.
Back to Top
2023
Should you use OWE for Public WiFi?
February 27, 2023
Opportunistic Wireless Encryption (OWE) otherwise known as Enhanced Open WiFi, is a new authentication method introduced in the 802.11 standard around 2018 to allow devices (WiFi client and Access Point) to negotiate an encrypted session between them to ensure the data transmitted is secure.
Well that sounds just like WPA or WPA2. Yes it does, except with OWE, the client (e.g. your smart phone) and the Access Point (AP) determine the PSK between them rather than a network administrator providing you a PSK (think of the WiFi password written on the wall in a coffee shop) that you enter in when joining the WiFi network.
Since it is the devices that determine the PSK and encryption, there is no password to share or to fall into nefarious hands. An additional benefit is it is easier for clients to join as there is no entering of passwords - just connect and go.
This seems to be the ideal solution for public WiFi networks - except not all vendors support it yet. At a minimum you would need a WiFi 6 capable AP that support OWE to provide the service, then only select clients (as of this writing in February 2023) will support it. There is an OWE Transition option that will allow clients that can connect to OWE to do, so while other clients stay on the open WiFi network. There are some security concerns around this approach and the fact that you still have an open WiFi network.
If providing WiFi to your customers is important, do what you need to do to give them the service they require. Do revisit and review your WiFi settings from time to time to see if and when you can move to a more secure footing - such as OWE - to protect you and the clients on the network.
Here are the known WiFi client OSs that will support OWE:
Back to Top
The Cost of WiFi: Balancing Upfront with Ongoing Costs
November 21, 2023
In an era dominated by connectivity, WiFi has become an indispensable part of our daily lives. Whether at the office, public spaces, or on the go, the convenience of wireless internet is undeniable. However, the true cost of WiFi extends far beyond the initial investment in hardware.
-
Upfront costs would be defined by the following criteria:
- WiFi Network Design and Configuration. For any WiFi implementation, this can define the overall success of the WiFi solution. Remember, even bad WiFi still works sometimes.
- WiFi and Network Hardware and Installation. The primary driver of most WiFi projects: how much does it cost and how soon can it be installed?
As these are tangible items that one can associate a cost (price) to, they tend to be the focus of any WiFi project. It is typically these costs that budgets, timing, and decisions are based upon.
-
Ongoing costs of a WiFi network are less tangible and are based on possibilities.
- WiFi Management Costs. Include hardware and software updates, configuration changes, and optimizations. Usually done when necessary (not planned) so there tends to be no cost associated with them except as required.
- WiFi Operational Costs. Can include electrical power, equipment licensing, and support subscriptions for the operation of the WiFi equipment.
- Training and Skills Cost. Having the visibility and access to detect, identify, and resolve WiFi related issues will vary based on the vendor and skills of the IT staff. A lack in either or both areas can lead to significant operational costs.
- Unaccounted Costs. These are the most difficult to quantify and factor into a WiFi solution – but are just as important. These include:
- Productivity costs due to downtime or inability to access the WiFi network.
- Inconsistent connectivity or inability to support newer devices and technologies on the WiFi network.
- Inability to handle scale/growth of devices on the WiFi network.
The true cost of WiFi goes beyond the initial investment in hardware and installation. Balancing upfront costs with ongoing support and management expenses is key to maintaining a reliable and secure wireless network. You may save on the initial investment but find that it leads to higher long-term costs due to increased downtime, security breaches, and the need for extensive support and troubleshooting.
In a world where connectivity is integral to daily life and business operations, understanding and budgeting for the true cost of WiFi ensures a seamless and sustainable network experience.
Back to Top
2021
Be Kind to Your Neighbours … WiFi
January 5, 2021
A common scenario I see when investigating Customer WiFi networks, is the presence of external WiFi networks broadcasting into the same space (i.e. two adjacent offices in the same building, each with their own WiFi network running at full power).
Not only does this cause congestion (too much traffic in a small area), but if these external networks are supporting older WiFi standards (e.g. 802.11b) then there is a possibility that their WiFi signals can trigger your WiFi network to switch to a legacy (protection) mode – even if you do not have any legacy devices on your network. This can result in lower throughput and performance speeds on your network.
As WiFi engineers, this is why we stress proper configuration and optimization of WiFi networks. Not just for the benefit of your network, but for your neighbours WiFi network as well.
Good WiFi makes good neighbours …
Back to Top
Understanding WiFi Speeds
February 6, 2021
It is very common for me to receive questions from colleagues and customers asking why they are not getting the advertised speeds on their WiFi networks when they run their `speed tests`. There are numerous reasons why this might be the case but most of the time it is expectation verses reality.
What do I mean by that? When you look at the different WiFi providers, they promote the newest and best capabilities of their products. This includes claims such as ‘the fastest’, ‘blazing speeds’, ‘up to 9.6Gbps’, etc.
What they are promoting is the theoretical speed of the technology (expectation) and not the reality (real world speeds). Why the discrepancy? Again, many reasons but it mostly comes down to two factors: the client device (i.g. your smart phone, tablet, laptop) and the WiFi environment you are working in (i.e. your home or office).
Think of your WiFi Access Point (AP) or wireless router as a highway and you can drive up to 200mph on this highway. This is similar to seeing WiFi6 (802.11ax) having speeds up to 9.6Gbps (theoretical).
Now think of your device (i.e. your new laptop) as the vehicle on this highway. It might be a nice sports car capable of 180mph. You might be able to hit 180mph if you are the only one on the highway. Now your friend is driving their economical compact car (i.e. smart phone) on the same highway and they can only do up to 80mph. So now you can see even though 200mph is available, the vehicles capabilities (80mph) limit how fast one can go.
Now put yourself on this highway at rush-hour (i.e. the WiFi network in your office). You have many vehicles, all with different speed capabilities moving on this highway. What happens at rush-hour? Unless you are lucky enough to be in the express lane, the overall speed is dictated by the slowest moving vehicles.
Only in near perfect and ideal conditions could we ever come close to the advertised speeds. The reality is WiFi (and WiFi clients) generally operate at a third to half of what is advertised by the network/AP. Putting an 80mph car on a 200mph highway will only ever get you 80mph.
Don’t get me wrong, the improvements in WiFi technologies and capabilities over the past five years have been significant and we can achieve very good speeds and throughput (close to 1Gbps in some cases).
The reality is most WiFi devices today range between 300 – 600Mbps (i.e. a slow car on fast highway) – and most people won’t notice the different between these speeds. What we need to do better is set the right expectations with users as to what the WiFi can actually provide them – a stable, consistent, and quality service.
Making WiFi better - one network at a time.
Back to Top
Good News for WiFi - 6GHz spectrum is now in Canada!
May 21, 2021
Great news for WiFi developers, MSPs, and consumer of WiFi services. The Government of Canada has just approved the use of the 6GHz spectrum (1200MHz wide) for use in Canada (here).
This not only bring new enhancements in speed and capacity but also allows for more room to design and use WiFi (as the 2.4GHz is very congested and the 5GHz band is becoming congested) in every increasing high density environments.
We won`t see 6GHz capable devices at the consumer level for some time yet, but this announcement is important for organizations that rely on wireless point-to-point (P2P) links for connecting their dispersed network locations (i.e. industrial site or campus). With the increase in bandwidth and speed, these wireless links will rival their more expensive wired (i.e. fiber) alternatives.
I personally am looking forward to the new devices and features that will leverage this new frequency spectrum.
Back to Top
Upgrade or Extend the Life of Your WiFi?
May 26, 2021
Are you having WiFi issues? Are you considering a WiFi upgrade? There are many factors that you need to consider as part of the decision to either upgrade your WiFi environment or to look at your current setup to see where improvements can be made to extend the life of your network for a bit longer.
If you have an older WiFi network (802.11b/g/n), a strong case can be made to do an upgrade. Just the continued evolution of WiFi devices (WiFi5, WiFi6) can justify this decision. There are however, other factors to consider. Here are a few when looking to decide if an upgrade or extension of the WiFi network is needed.
- Is it a technology or capacity reason to upgrade your WiFi? If the majority of your devices are, or will soon be, WiFi5/WiFi6 capable or you have a greater number of WiFi devices connecting and using the WiFi network, this would be a driver for a WiFi technology upgrade.
- Are your WiFi issues based around poor coverage, performance, connectivity? These issues are more likely to be based on WiFi mis-configuration, lack of optimization, or running default settings. In these scenarios, you may not need a network upgrade but rather WiFi optimization and tuning of the network. Even older 802.11n networks can be optimized to provide reasonable capacity and performance for your systems and users without requiring a full network upgrade.
- What clients (devices) do you used today in your WiFi environment that needs to be supported after and upgrade? We continue to see in many warehouse and industrial environments, the continued use of 802.11b/g/n devices (i.e. hand scanners, time clocks, tablets). We call these LCMI (Least Capable Most Important) devices and they are typically a key element in any upgrade decision.
- Whether you upgrade or extend the life of your WiFi network, can you retire older WiFi protocols (802.11b/g) to help with the overall performance and operation? Moving to newer protocols and standards is ideal wherever and whenever possible. Removing support for 802.11b (and possible g) can greatly improve your WiFi performance and operation.
- What is your timing to complete a network upgrade and budget to do so? These two considerations alone can determine if a WiFi upgrade is feasible or not. Balancing the technology needs against your business will help make an informed decision.
A brand new WiFi network can still be deployed badly.
Taking care to ensure your investment is operating in the most efficient and optimal way will benefit everyone in the long run.
Back to Top
Using Wide Channels
October 19, 2021
One of the aspects of WiFi to gain higher throughput speeds, is to implement wider channels (40, 80, 160 MHz) from the standard 20MHz. While this may seem to be a positive configuration approach, there are questions that need to be considered when looking to implement wide channels on your WiFi network.
1. Do you have enough available channels on your WiFi network to support wide channels? If you are operating in the 2.4GHz band it is never a good idea to use wide channels (40Mhz max) as you only have three (3) usable channels to start with and if you have more than one Access Point (AP) then you will already begin to have problems (channel over lap). In the 5GHz band, you will start with twenty-five (25) 20MHz channels that would be reduced for each channel width option you select (40MHz = 12 channels, 80MHz = 6 channels, 160Mhz = 2 channels). Depending on the number of APs you are using in your area, channel overlap or channel interference from neighboring WiFi networks will have an impact on your WiFi operation when using these wider channels. In a high density environment (many APs within range of each other), this will become significant as channel overlap and interference is a leading cause of poor WiFi operation and performance.
2. Can your client devices support these wide channels? As mentioned in previous articles, the WiFi client devices play a significant role on the WiFi environment as they determine where and how they will connect and use the WiFi services. As most client devices are typically small and battery operated, they will not support the larger channel widths as these require the client device to use more battery power to transmit and receive. Also depending on the protocol support of the client device, not all features may be implemented to take advantage of the wider channels. An 802.11ac (WiFi5) device may only be able to support 20 or 40MHz wide channels so it would never get the benefit of an 80MHz wide channel on your WiFi network. These clients will only ever use the 20 or 40 MHz portion of the channel so there is wasted channel space and unnecessary WiFi overhead generated on the network to maintain this configuration.
3. Is your RF environment `clean` enough to allow for wider channels? A lesser known impact of increasing channel widths is for each increase in the channel width (i.e. 20 -> 40 MHz) there is a 3db increase in the resultant noise floor for that channel. This means that your signal to noise ratio (SNR) will also be impacted. So if your network was designed for a minimum signal strength of -67dbm with 20db SNR for 20MHz wide channels, if you increase your channel width to 40MHz, to maintain that same SNR (which is an important parameter for many applications such as video and voice applications), then your minimum signal strength will have to change from -67dbm to -64dbm (3db increase) to maintain the same minimum levels for the clients. If your RF environment already has a high noise floor (-85dbm) or has a number of external WiFi networks that overlap with the current channel plan of your network, achieving these minimum parameters will be difficult if at all.
Like all WiFi configuration options, there are pros and cons to each setting, and each should be examined for its applicability and value it will bring to the overall performance and operability of your WiFi.
Building better WiFi one network at a time.
Back to Top
Top 5 Tips for Better WiFi
December 30, 2021
The thing about WiFi is it will work even if it is not implemented correctly. Here are a few tips to fix some common mistakes made with WiFi deployments that can provide immediate improvements.
-
Having too many SSIDs. An SSID is what we see and select when we want to connect to a WiFi network. Most WiFi networks can support several SSIDs and are typically used to provide access to different users or services. Having too many SSIDs available on your network can result in slow performance as the Access Points (APs) have to spend more time broadcasting and responding to these SSIDs rather than servicing the WiFi users.
Best practice is to have four (4) or less SSIDs for best results. -
WiFi power settings too high. An all too common situation on WiFi networks. Power setting set too high can result in several conditions that can impact the behavior of the APs as well as how the WiFi clients interact with the WiFi network. This is more pronounced in multiple AP deployments but some of these effects can be seen in single AP deployments as well. Transmit power set to high can cause:
- Co-channel interference (CCI) between APs on the same network (very pronounced in the 2.4GHz band and in medium to high density AP deployments).
- Interference from external WiFi networks operating on the same channels (see my Be Kind to Your Neighbours WiFi article).
- Because it is the WiFi client that decides what AP to connect to, if there are several APs with a strong signal present, the WiFi client may `hop` between APs in an attempt to connect to the best one. This is observed as frequent connection drop and re-connection by the users.
- Reduced throughput due to high contention rates. If your WiFi client is trying to transmit to its local AP but `hears` and AP from the other side of the building, operating on the same channel, and also trying to transmit, one of the devices will back off and wait for that next opportunity to try again (remember WiFi is a very polite protocol). If this happens frequently enough (as it does in medium to high density WiFi environments), the WiFi clients will have to wait longer periods of time between transmit opportunities. This is observed by the users as very slow throughput (speeds). This is a killer scenario to any time sensitive applications such as VoIP (drops) and video streaming (buffering).
- WiFi clients typically cannot operate and the same transmit power levels as the APs (especially mobile devices like smart phones, IoT devices, etc). If your AP is transmitting at 100% full power but your client device is only capable of 50% to 75% of that power level then you will have a power imbalance. This means the client is far away from the AP, it may be able to hear the AP but it does not have the power to send a response signal back to the AP. The AP will assume the client did not receive the transmission and will attempt to send it (retry) again. Multiple retries will be observed as slow throughout or even dropped connections.
Reduce transmit power to match your least capable WiFi client. -
Use of wide channels. This is appropriate in the right situation to achieve higher throughput (speed). A typical WiFi channel is 20MHz wide. In the 5GHz band, 40, 80, and 160MHz wide channels can be used to increase throughout speeds. This sounds great until you consider other factors on your WiFi network such as the number of APs you have, the band you are applying the channel width to (2.4GHz or 5GHz), and the capabilities of your WiFi client devices.
A few considerations to help you determine if wide channel use is for you:
- NEVER USE 40MHz channels in 2.4GHz band. You only have 3 channels to start with and you cannot afford to lose any of them.
- Can your WiFi client devices support wide channels? Most modern WiFi devices will support 20 and 40MHz wide channels with a few supporting 80MHz. If a WiFi client is connected to an 80MHz channel but can only use 40MHz of it, then the other 40MHz is wasted. A better used would be to allocate that 40MHz to another channel so that multiple clients could be active on the WiFi network at the same time.
- The more APs you have in your network, the smaller your channel width should be. This is mostly to prevent co-channel interference (CCI) between the APs that will kill your connection quality and throughput.
- NEVER USE 40MHz channels in 2.4GHz band. You only have 3 channels to start with and you cannot afford to lose any of them.
Set appropriate channel widths to your network. When in doubt, use 20MHz. -
Legacy WiFi support. It is great that WiFi is backwards compatible to older WiFi technologies but it can also be a detriment to the overall performance of the network. This really only effect the 2.4GHz band so it is most pronounced with older WiFi such as 802.11b devices. With 802.11b, the WiFi needs to operate a lower data rates (1 and 2Mbs) for communications to be managed properly and will reduce your overall network performance. If you have specific WiFi devices that require this standard then absolutely keep it enabled, but most modern WiFi devices (post 2010) will support 802.11n (2.4GHz/5GHz) and better so this allows for much higher data rates and performance of your network.
When appropriate disable support for 802.11b and if applicable 802.11g. Run your 2.4GHz network with 802.11n. -
Where you place your Access Points (APs). AP placements can mean the difference between good and excellent WiFi. Even moving an AP 3 meters (10 feet) can have a drastic improvement on signal coverage and quality. This is mostly due to the environment the APs are deployed (walls, building materials, obstructions, etc) but also where the WiFi devices will be used relative to the AP. Most APs are deployed for convenience and security, not for optimum service (hallway deployments in building is a good example of this). It is understood that there are situations where this type of deployment cannot be avoided so employing a good WiFi designer will help you maximize the performance of the WiFi in these scenarios. The best guides for WiFi placement are:
- Put the APs where the WiFi clients are.
- Never put an AP in a hallway intersection. This causes `hidden node` problems with client devices and is most often seen in hallway deployments.
- Mount the APs as they were designed. Usually horizontal on the ceiling. This ensures the best and most appropriate distribution of WiFi signals.
- Keep the AP away from obstructions. Closets, metal piping, duct work, and concrete walls will impede WiFi signals. Avoid them.
Think through your placement of APs before installing. Using WiFi design software or enlisting the help of a WiFi designer will make this process easier.
Making WiFi better - one network at a time.
Back to Top
2020
Thoughts on 6GHz
May 14, 2020
Now that the FCC has approved the 6GHz frequency band for unlicensed use, understanding the implications and use of this additional frequency band will be important for the continued growth of WiFi. (Note: For us in Canada we are still pending on CRTC approval as of this writing) In recent episodes of the Clear To Send podcast (https://www.cleartosend.net/) they discussed the new 6GHz spectrum for WiFi. I had to listen to these episodes a few times as there was a lot of information to digest and to understand how this would be applied and impact the way we approach WiFi designs today.
Why we need 6GHz.
WiFi is ubiquitous and we rely on it more and more. As more devices use WiFi or share the same frequency bands as WiFi (IoT devices, cellular 5G), this current space is quickly becoming congested. We need the additional room to provide for our ever increasing WiFi needs. 6GHz capable devices will be labeled as WiFi6E.
What 6GHz provides us.
Similar to the 5GHz band, 6GHz provides higher bandwidth and throughput speeds. 6GHz also has many more channels than the 5GHz band, allowing for these wider channels and higher throughput (important for applications such as 4k video streaming). A second feature of the 6GHz band will be the use of Power Spectral Density (PSD). In the 2.4GHz and 5GHz bands PSD determines the power output of a radio as a fixed setting regardless of the channel bandwidth (i.e. 20, 40, 80). In 6GHz PSD allows for the dynamic increase of the radio power output as the channel width increases (40, 80, 160MHz). This is important for reducing the effect of the ambient RF noise as the channel width is increased and improves the throughput for signal sensitive applications such as 4k video streaming.
Limitations of 6GHz.
WiFi is not the first to the 6GHz band. Telecoms use some of the 6GHz frequencies for wireless connectivity/backhaul for their networks. These identified frequencies will be excluded from the available channels. Another limitation will be antenna types. 6Ghz will be primarily for indoor use (internal antenna that are omnidirectional or semi-directional). Outdoor use of 6GHz capable APs will be for specified/limited use with no external/detachable antenna.
6GHz equivalent of DFS.
As mentioned above, some of the channels in the 6GHz band will be excluded as they are already in use with some Telecom providers. This is handled by Automated Frequency Coordination (AFC) which is loosely the equivalent of the DFS channels in the 5GHz spectrum.
Final Thoughts.
6GHz and WiFi6/6E will increase the usability and use cases for WiFi especially when compared to cellular 5G services. A few advantages of this will be lower cost to deploy and maintain and it can be used in low density (population) areas where 5G does reach. I for one will be interested to see how it performs and to really dig into its use cases and applications.
Back to Top
All Wireless networks start with a wire ...
September 29, 2020
Its interesting to experience peoples perception of technology. Be it from really good marketing or overly generalized concepts, the tendency to expect more than what the technology is able to provide is quite prolific. Seems that WiFi is not immune to this.
To a certain degree, I believe we in the WiFi industry share a lot of this responsibility. In promoting WiFi as easy to install and use, we have obscured the nuances and complexities of what is required to have not just good WiFi but great WiFi (although many of us are working on trying to change that perception).
One of the areas that I keep running into is - `Its wireless. Why do we need so may wires?`. Think of your WiFi like the fixtures in your house. It is the light or faucet that you use - not the electrical wires or pipes they are connected to. However, without these wires and pipes, your fixtures are non-functional. Same applies to WiFi.
If these wires and pipes (i.e. the wired network) are not well constructed, installed, and maintained, your fixtures will not perform the way they should. As such, your WiFi can only be as good as the network it is plugged into. A good WiFi design will account for the wired network and its optimization as part of the overall design.
Secondly, as advanced as WiFi has become over the years (WiFi6, 6GHz spectrum, OFDMA, etc) the capabilities toted for WiFi are theoretical and usually much less in real world applications. This is not to diminish the value of WiFi but to highlight that it is just part of an over all system that we use.
To use another analogy, like a freeway system, WiFi (the on and off ramps) is great at connecting and aggregating many transient end points (i.e. wireless devices) to the network (the freeway). WiFi has yet to achieve the speed and capacity of a wired network (although it is getting closer), and if you have a large WiFi footprint (many Access Points and WiFi networks), the wired network becomes even more critical to the overall operation and performance.
To have a great WiFi network, you must first start with a wire ...
Back to Top
Five Steps to Effective Troubleshooting (... actually Six)
November 20, 2020
This is a topic I have wanted to share for some time now. A little throwback to my support days…
Whether you are trying to resolve a network communication issue, software application issue, or just trying to get your lawn mower to start, there are basic steps that you should always follow to efficiently find and resolve a problem.
These steps can be applied to an entire system or any part within a system. The trick to effective troubleshooting is to not jump to conclusions (surprise!). That method – although seemingly fast – is almost never correct and usually just addresses the symptom(s) not the problem. Which means you will be coming back to troubleshoot this again (and again, and again).
Methodically working your way through a problem to the root cause – may seem longer - but it also means that you can get to the real root cause and resolve the issue - once.
Here are the steps that I have used in practice and found to be effective in getting to the desired outcome.
1. Know the Environment. Knowing and understanding how things work (end-to-end) for a given system/process is key. If you do not know what it should be doing you will not be able to effectively identify any issues.
2. Know the Parts. Knowing the parts or steps within the system/process and their expected behaviour is what enables you to observe, measure, and track the results.
3. Start at the Beginning. Many issues can present themselves in a very benign way that are often overlooked or dismissed. This is leads to false assumptions and diagnosis. Begin with the input and observe/measure the behaviour at each point. Does the behaviour/output match what should occur, or does it differ?
4. Rinse and Repeat. If it differs, then repeat Step 3 starting at the point just before the observed issue was detected and measure again. This is to ensure you have accurately isolated your failure point. Do this as many times as required.
5. Diagnose and Resolve. Once you have identified the point where the issue is occurring, used all available tools and information to determine the root cause and develop a fix/resolution to the problem.
6. (Bonus Step) Documentation and Preventative Measures. Seems obvious but in busy environments documenting the issue and putting preventive measures in place can be easily overlooked.
Notice we did not even start to troubleshoot until we were at Step 3. This should highlight the importance of completely understanding the environment and its’ expected outcomes before you begin. In using this method, you will likely be surprised with the actual results.
Remember, it was the tortoise that won …
Back to Top
2019
Turn down the radio ...
July 9, 2019
Unlike the song from the ‘80’s, turning down you WiFi radios is a good thing. As WiFi is deployed in higher density environments (think offices, arenas, conference centers, MDUs, etc) the impact of co-channel interference, client stickiness, airtime availability and utilization become factors in the overall quality and performance of the WiFi service.
There is no one magic setting for a properly configured and tuned WiFi network but certainly the radio transmit power level is a good starting place. This one setting is the foundation for all other radio settings to operate from.
Lowering the radio transmit level reduces the cell size of a given AP and will allow it to only ‘hear’ its immediate neighbor’s (not the AP two floors away). This reduction in cell size will also decrease the chances of co-channel interference for the same reason. Thirdly, as clients roam within a WiFi area, they are more likely to associate to their closest AP as it should be providing the best service options for that particular location.
The other consideration is setting the appropriate power level for each band (2.4 and 5). As per my previous article (Re-Thinking Wi-Fi Surveys – Part 2), 2.4 GHz signals propagate differently than 5 GHz. Tuning these bands to a proper output level will further improve your operational efficiency and quality (especially in 2.4 where co-channel interference is greater).
Radio power levels are a first good step in improving your WiFi network and one where you can see the benefits almost immediately. From there you can adjust other settings to further refine your network.
Turn it down … and rock on.
Back to Top
The Value of WiFi Surveys
April 16, 2019
As we have referred to many times, the one size fits all for Wi-Fi is not relevant any more. Designing, deploying and managing today`s Wi-Fi networks is possibly one of the most complex and time consuming activities for network administrators, especially with the compounding effect of IoT technologies, online applications and user expectations.
So how do you make this easier and manageable for shrinking IT resources and growing demand for services?
Most Wi-Fi manufacturers today provide an extensive set of tools and capabilities into their products to allow network engineers and administrators to deploy and manage a Wi-Fi network. Looking at Access Point (AP) operational states, number of connected clients, data throughput are all relevant and required information needed to effectively manage a Wi-Fi network on a day to day basis.
But this only provides half the picture.
What is missing is the view of the network from a client device perspective. (Note: yes there are products and tools coming onto the market that are beginning to fill this role but they still provide a limited view). As we know, the Wi-Fi devices decide how and where they will connect to the Wi-Fi network. How we as designers and engineers design and configure a Wi-Fi network can only ‘suggest’ to the device how they should (not will) associate and use the available Wi-Fi services.
This decision on the device as to where and how it will connect to the Wi-Fi network is based upon several variables that may not be known or visible from the management side of the network. This can include the relative signal strength, sources of external interference, co-channel interference, physical obstructions, less than optimal Wi-Fi configurations, etc. This is compounded even more with environments that are constantly changing (public spaces, convention centers, marinas, retail, etc).
You do not need to be doing these Wi-Fi surveys constantly, but they should be part of a regular network health check program. With how fast Wi-Fi technologies are changing, a Wi-Fi survey performed at least once a year or whenever a significant network change is implemented, will assist in understanding the operation of your Wi-Fi network.
Knowing the state of the Wi-Fi network on both sides of the AP will not only give you the insight to the true performance and utilization of your network but also help you in identifying and addressing potential issues before they become issues. This allows network administrators focus on the planning and growth of the network for the users, devices, services and applications that use it.
Back to Top
2018
Wi-Fi Design: Science, Art or Both?
June 5, 2018
As Wi-Fi technologies and networks become more prevalent, how they are used and the expectations of the users on them is also changing. Whether you are in an office environment, public area such as a sports arena or in a campground, the demands and requirements place on a Wi-Fi network today are vastly different than they were even two years ago.
Hence the days of a ‘one-size-fits-all’ or ‘standard-cookie-cutter’ Wi-Fi network is no longer viable. With users carrying multiple Wi-Fi enabled devices, each with different applications and services, it is vastly changing the data profile on the network. And it is not just data usage. How users join, interact and leave the network is now so fluid that the traditional static Wi-Fi configurations that we have long relied on are showing their limitations.
So as Wi-Fi designers, what are we to do? How can we anticipate how a Wi-Fi network will be used next month let alone next year? Fortunately Wi-Fi technologies are catching up with how people interact with them. Higher capacity APs, multiple antennas, MU-MIMO all provide us with greater options in how a network can be shaped. That is the Science part.
It is however not a pure technology based approach. There is a degree of intuition that needs to be included in a design. Placement of APs, how one organizes AP groups, when to steer connections and on-the-fly configuration changes is where the Art of design comes into it.
Being able to successfully blend the two is easier said than done. One will stumble and make mistakes along the way but that is how you will develop the intuition side of your craft. I was going to call this article the Zen of Wi-Fi Design – but that seems a little presumptuous given that Zen implies a mastery of something which we clearly have not. The Science and Art of Wi-Fi Design more accurately describes what we do. We are good at our craft but recognize that there is room to grow and develop it further.
Know the fundamentals, be bold in your designs, push the boundaries of the technology and remember that it is people that we are ultimately providing a solution to.
Back to Top
2016
Thoughts on Wi-Fi Meshing…
October 19, 2016
I have spent a lot of time these past few months visiting locations where Wi-Fi has been deployed over a localized area (predominately outdoor environments) for public use. One of the common conditions I see during these visits is the prevalence of meshing the APs to each other to build out the Wi-Fi network (there is a significant difference between meshing and point to point wireless connections which I will touch upon later).
I certainly understand the reasons and the perception as to why this would seem to be a good idea (mostly to keep costs down), but there are fundamental aspects that the installers may not have considered when using this deployment technique.
The main aspect is that a meshed connection utilizes the same Wi-Fi radios to establish and maintain this wireless connection as is used to serve the Wi-Fi clients. This means that the radios have to split their time and resources (see my previous article Re-Thinking Wi-Fi Surveys Part 3) between serving the local Wi-Fi clients and maintaining this wireless connection. You can think of this as the Wi-Fi radio spending half its time serving clients and the other half transferring data across the wireless link.
To put this another way, if your Wi-Fi AP is capable of providing 100Mbs of service, once it is meshed, this available capacity is now cut in half (50Mbs). This compounds further as you mesh out to additional APs (called a hop). As you move further away, the available speed/capacity of the Wi-Fi service at those locations is continuously cut in half (see Figure 1).
Figure 1: Available Wi-Fi over a Meshed Network
As you can see, clients that are farthest away from the ‘root’ AP will have the least availability of Wi-Fi speeds and capacity.
In contrast, point to point is a dedicated wireless connection between two APs that the local wireless clients do not use. The results are you will lose some of your radios for servicing local clients but the dedicated connection will ensure reasonable throughput speeds and will not degrade the overall Wi-Fi service speed and capacity by very much. Point to point also has the advantage of connecting locations that are farther away than what a typical meshed (or non-fibre) connection could do. Like cabling however, they do add costs to a network deployment.
Meshing is a tool to be used by Wi-Fi designers and installers, but only under specific conditions and only when the effects and results are considered. In general, if you are looking to provide a quality, stable and reliable Wi-Fi service, then you should avoid meshing.
In the long term, you will be better off to make the extra investment in the cabling infrastructure upfront; even consider a smaller Wi-Fi foot print initially and build over time if you have to operate around budget constraints. This will ensure an optimum Wi-Fi service and most importantly – happy customers.
Back to Top
Re-Thinking Wi-Fi Surveys Part 1
August 11, 2016
An important aspect of designing and implementing a Wi-Fi network is the Wi-Fi site survey. This is usually done pre-deployment to determine the state of the existing area where Wi-Fi services are to be added or upgraded. Traditionally these Wi-Fi surveys are done from the perspective of the Access Points (APs) to determine the Wi-Fi coverage area and signal strength from a given location.
This is a valid approach when trying to determine the minimum number of APs needed to provide Wi-Fi services within a given area. With the dramatic increase of mobile and other Wi-Fi enabled devices, this approach is no longer sufficient to properly assess and design a Wi-Fi network for today and tomorrow. Why? The proximity of a mobile device to an AP where it can effectively `talk` has to be considered.
NB. There are other aspects to consider when assessing and designing a Wi-Fi network – local environment, RF sources, density - but for this article we will be focusing on the effective ranges of the devices.
One analogy use to explain this is having two people in a room. One speaks in a normal voice (mobile device) and one speaks with a loud voice (AP). If these two people are close together, they can easily hear and talk to each other. As they move farther apart (as mobile devices tend to do), the normal voice person continues to hear the loud voice person. However, the loud voice person finds the normal voice person harder to hear as they move away. Eventually they can no longer ‘hear’ the normal voice person.
This is essentially becomes the effective range of the Wi-Fi service. It is not how far away a device can receive the AP signal but rather how far away the AP can receive the mobile device signal. This is supported in looking at the specifications of the various devices. Most APs will transmit their Wi-Fi signal between 100-200 mW (milliwatts) while most mobile devices transmit between 10-40 mW. The lower the transmit wattage, the smaller the range.
When performing a Wi-Fi survey or analyzing the survey results, this aspect needs to be a factored into the process. As Wi-Fi continues to become a ubiquitous utility (same as electricity and water), this change in Wi-Fi design needs to be adopted to ensure the continued effectiveness and value of Wi-Fi networks in the future.
Back to Top
Re-Thinking Wi-Fi Surveys Part 2
August 19, 2016
Most access points (APs) today are dual radio units. One radio is typically operating in the 2.4GHz band (for legacy devices and lower speed devices) and the other radio in the 5GHz band (for newer devices and bandwidth intensive services).
An area of confusion is the service range of the 2.4GHz band vs. the 5GHz band. Measurements will show that the 5GHz band covers approximately 60% of the area covered by the 2.4GHz range as measured by signal strength.
Measurements will also show that the 5GHz band cannot penetrate barriers (walls, doors, trees, water, etc) as well as the 2.4GHz band. The reason for this is that higher frequencies are reflected/absorbed by the surrounding materials much more readily than lower frequencies (you hear the bass coming from another room before you hear the higher pitches). This is one of the main reasons why the 2.4GHz is still prevalent and relevant in today’s Wi-Fi networks.
With this information why would one want to deploy Wi-Fi using the 5GHz band? There are several reasons.
Once you understand the capabilities of each band, you can use these to your advantage to deliver a quality Wi-Fi service to the user.
Matching this with the effective ranges (previous article), you can now begin to develop the picture of what your Wi-Fi network will look like.
Back to Top
Re-Thinking Wi-Fi Surveys Part 3
September 6, 2016
Previously, we discussed how Wi-Fi and network designers need to consider the band and effective range of access points (APs) and mobile devices to determine how they will interact and operate in a Wi-Fi network. This will be a determining factor in the placement and spacing of APs in your network.
For the final part of this series, the third critical aspect of a Wi-Fi network to consider is capacity – or - how many users an AP is expected to serve.
To continue with the conversation analogy, you (AP) are a vendor with a single customer (mobile device). You are the only two present so transactions can flow freely. Soon another customer (another mobile device) joins you so now you are dividing your attention between the two of them and yourself. Soon three more people approach the counter (more mobile devices) and now you are listening and responding to five separate customers. This is basically how an AP interacts with Wi-Fi devices. It will listen and respond to each device but can only do so one at a time.
One to One Communications
One to Many Communications
The next thing to consider is how many ‘customers’ can an AP manage. This is very subjective and will vary between Wi-Fi vendors but a good rule of thumb to follow is most APs today can handle 50 concurrent connections (Wi-Fi devices). There is also a concept of ‘over-subscription’ whereby you plan to service more than 50 devices per AP. This can be applied to environments with a high level of transient (short stay) users as not all devices will be active at the same time. For example, you could have 75 devices connected to an AP but only 50 devices are active at any given time. Environments where Wi-Fi users will have longer dwell times and/or use media rich applications, then you need to plan on a smaller number of connections per AP. The environment and Wi-Fi usage requirements will determine where and when you can apply this over-subscription element.
So now we are not just planning and designing for coverage and service range, but for capacity as well. The key to this aspect is how often do you expect to see these high capacity situations? As network designers we have to decide and balance our designs between this peak usage and the nominal usage.
These may seem to be more design rather than survey considerations but when doing a Wi-Fi survey, we need to determine if and how these requirements are currently being met.
Back to Top