- Wi-Fi Standard in Use
There are five Wi-Fi standards that you can deal with outside a museum, a military base or a telecom operator’s installation: 802.11a, 802.11b, 802.11g, 802.11n, and 802.11ac. Among these, 802.11a and 802.11b are quickly becoming the sort of thing Indiana Jones might be interested in.
These standards specify different frequency bands, different encoding technologies, RF parameters (such as receiver sensitivity), and maximum speeds. Furthermore, not all devices support all standards.
Consequently, the combination of client devices and Wi-Fi standards in use already places a theoretical limit on the maximum speed and range that you can achieve.
- Signal Power
802.11-family standards are all industry standards and are only concerned with networking. But manufacturers need to respect other regulations as well.
In particular, due to interference and health concerns, RF equipment used for personal and most commercial purposes is limited in terms of emission power.
Between this limit and those imposed by industrial standards, most current Wi-Fi devices are inherently limited to ranges of up to 90-100 ft. (for 802.11 ac and 802.11g) or 200-225 ft. (for 802.11n).
- Equipment Quality and Build
Industrial and government standards place hard requirements on radio parameters of networking equipment but do not make specific requirements in terms of performance.
Consequently, the quality and performance of a Wi-Fi network also depend on a myriad of design choices that manufacturers make. Some of these are deliberate choices, as manufacturers try to cover the entire breadth of the price-performance spectrum. Others are pretty much accidental, and it’s just the best that a manufacturer can do.
- Antennae: Count and Quality
The antenna is a critical component of a device’s RF chain. Its build – size, material and connector quality – is therefore critical to the quality of your Wi-Fi signal. Antenna count can also influence your Wi-Fi connection quality, in many ways.
Antenna quality tends to be a difficult thing to evaluate. For example, it’s important for antennae to be of particular sizes, not necessarily as big as possible. Consequently, antenna quality is something you tend to learn of, rather than evaluate by looking at a device.
- Firmware Quality
The firmware running on a Wi-Fi router, Wi-Fi access points or Wi-Fi repeater is responsible for much of the RF operation of the device. It monitors signal quality and strength from all client devices, handles channel allocation, adjust signal power and so on.
Bugs in firmware can therefore have a negative impact over your Wi-Fi signal and connection quality.
Some manufacturers issue updates for their devices’ firmware. Some of these updates fix connection quality issues, but it’s important to stay up-to-date with them regardless, as they often fix security issues, too.
- The RF Chain
The RF chain is that part of a device – smartphone, tablet, laptop, Wi-Fi access point etc. – which encodes, transmits, receives and decodes radio signals. Its quality is critical to the quality and strength of wireless signals, and to the quality of the network connection they carry.
Sometimes, RF chain quality is not very symmetric. The network performance of a high-quality smartphone, for example, will be negatively impacted by a poor-quality Wi-Fi AP.
- Client Equipment
When it comes to client equipment, it’s not only the quality of the RF chain that determines your Wi-Fi networking experience. Other parameters, like the build quality and the quality of Wi-Fi drivers, can affect a particular device’s signal quality or speed.
It’s important to keep this in mind and to have a good overview of what client equipment you will deploy. Realistically assessing the capabilities of client equipment is an important part of determining the requirements of a Wi-Fi network.
Not sure what the requirements for your Wi-Fi network are? Schedule a FREE, no-obligations on-site survey with ACCL. Our report will tell you all your need to know!
- Error Mitigation Capabilities
The quality of the RF signals going between a smartphone and a wireless access point can be degraded by a variety of factors, from RF interference to sheer distance.
Some devices support a number of error mitigation algorithms, such as LDPC (Low-Density Parity-Check). Activating these algorithms can improve signal quality and improve network performance under certain conditions.
- Environmental Factors
Hardware aside, practical experience shows that deploying the same equipment in different environments results in different performance characteristics.
Some environmental factors, like where you install a wireless access point, are firmly under your control. Others, such as RF noise and interference aren’t fully under your control, so you need to take them into account when designing a Wi-Fi network.
- RF Noise and Interference
All Wi-Fi devices operate in several frequency bands, in the 2.4 GHz and 5 GHz spectrum. The “all” part is very encompassing: that includes your Wi-Fi devices, your neighbour’s Wi-Fi devices – all of them operate in this spectrum, and sometimes they can interfere with each other. This has a negative impact on the quality of Wi-Fi signals.
Not all interference is due to other Wi-Fi devices. Other wireless protocols, such as Bluetooth and ZigBee, operate in the same frequency band as Wi-Fi. And sometimes interference is entirely accidental: poorly-screened USB 3.0 cables, for example, can generate significant RF noise.
The presence of RF interference decreases the performance of a Wi-Fi network, and its effects tend to decrease the closer you are to the Wi-Fi access point.
Consequently, wireless access points are placed so that they are sufficiently close to any client equipment, while still far apart enough so as not to interfere with each other.
- Office Construction
The size of the rooms, the material of the walls and ceiling, and even the construction and relative height of the surrounding buildings influence the quality of Wi-Fi signal in your office.
All these parameters influence both how signals from your equipment propagate, and how much interference from the outside can get in.
RF signal propagation is one of the most complex domains of physics and electrical engineering. More often than not, we have to rely on both simulation and measurements in order to figure out where to place Wi-Fi access points for optimum performance.
- Access Point Location
Due to all these factors, the location of a wireless access point has a great deal of influence over Wi-Fi signal quality and strength.
Not only distance from client equipment, but proximity to walls, structural elements such as reinforced concrete pillars, or large metallic objects like cabinets, can be important factors to consider when deploying a Wi-Fi access points.
- Device Installation
Where exactly an access point is placed is not the only factor that influences performance. Many other factors related to the position of an access point have important consequences.
For example, an antenna does not radiate RF signals uniformly. There is a narrow region, right on top of the antenna, where the signal strength is very low. Antenna orientation, both in relation to client equipment and to the surrounding environment (walls, structural elements) can influence Wi-Fi signal quality.
Other important factors related to device installation include ventilation, RF screening (deliberate or not) and height.
What can interfere with WiFi signal and network factors
Some of the factors that influence wireless performance are not related to a specific device, but to the network as a whole. Most of these factors are under your control, and taking them into account when devising a Wi-Fi network is critical to its performance and reliability.
- Number of Connected Devices
So, what can interfere with Wifi? Have you noticed how, when you are in a very crowded room, it’s sometimes hard to hear what another person is hearing? Even though you can definitely hear the noise, it’s hard to isolate one specific voice.
A somewhat similar phenomenon can happen in RF devices, too. Only a finite number of client devices can be connected to an access point at a given time.
It looks like this problem is easy to solve: if there are 400 devices in an office, and an access point can support up to 100 devices, 4 access points should be enough, right?
Unfortunately, Wi-Fi devices tend to be very mobile today. Sometimes – during an all-hands meeting, for example – 200 of those devices can be in a single room.
Consequently, it’s not only the device count that matters, it’s also the usage patterns of those devices. Crowded areas, like cafeterias or large conference rooms and auditoriums, may need to be over-budgeted.
- Uplink Speed and Load
Wi-Fi access points still have to connect to the rest of your network, and then to the Internet. Traffic between different departments, for example, will go through more devices than just a Wi-Fi access point. And, of course, Internet traffic goes through your ISP.
The performance of your Wi-Fi connection depends on how fast and how busy the network on the “other side” of the wireless access point is.
This is not something that you can mitigate on the wireless side, but it is something that you need to take into account. Wi-Fi traffic tends to be very diverse: smartphones can download hundreds of megabytes of firmware upgrades, and the age of BYOD means that company networks need to accommodate some personal traffic in the background as well.
- Equipment Configuration
Just like a car can be tweaked for better performance, networking equipment can be configured to improve the speed or reliability of its connections.
Sometimes, this configuration is strictly about optimisation, such as enabling the use of an error mitigation algorithm. But sometimes it’s really a matter of right and wrong.
For example, the exact frequency bands that a device can use, and the maximum signal strength, vary from one country to another (confusingly enough, some parameters differ even between the UK and Australia, for instance).
Some devices are pre-programmed for a given market, but others need to be configured for operation in a particular region. Operating under the wrong parameters can lead to poor signal quality and sub-optimal performance.
- Network Configuration
The configuration of your network will not affect the quality and strength of Wi-Fi signal, but it will affect the performance you can get out of it.
Correct (or incorrect) configuration of your core network can affect the bandwidth and latency you get out of your wireless access points, sometimes in unpredictable ways.
Furthermore, Wi-Fi networks have a different structure and very different behaviour from wired networks. They aren’t designed in the same way, and integrating the wired and wireless sections of your network is an important aspect of network design.
If you want to make sure that you have a fast and reliable Wi-Fi network, and you see to what can interfere with WiFi signal, we’re just a phone call or an email away. We’ve been installing various types of networks in London for more than 20 years. Get in touch with us for your complementary, no-obligations survey.
Related topics: How to set up WiFi in the office Point to point WiFi