Wi-Fi has improved massively in recent years with claimed speeds increasing from 11Mpbs (802.11b), to 54Mbs (802.11g) and 802.11.n claiming 300 to 600Mbps, depending on the number of radios and the radio frequencies used. The latest standards such as 802.11ac claim to provide wireless speeds as high as 3Gbps.
We have used the word 'claimed' for good reason. In the real-world environment of your home, the theoretical speeds quoted are never achieved. There are several reasons for this including:
To overcome some of these problems the Wi-Fi hubs/routers are becoming more intelligent but the bottom line is that as more people use Wi-Fi and more devices get connected to the Wi-Fi, the more congested the bandwidth becomes and the lower the performance for all. Wireless bandwidth is a finite resource and should be used wisely.
From a home security and automation perspective, we still don't consider Wi-Fi to be reliable enough or secure enough to use and opted for wired IP networking by default. We don't see this situation changing in the foreseeable future.
The Many consumers don't understand the difference between their Internet connection and their Wi-Fi connection and many talk about 'Wi-Fi speed' when they mean their Internet connection speed. This is very evident from the trials we have been involved in and the numerous Internet forums.
When you run an Internet speed test over Wi-Fi, you are not going to get very useful results because you are testing two things at the same time and can not be sure which is having the most impact on the results. There is only one proper way to run a speed test.
Earlier Wi-Fi systems operated in the 2.4GHz frequency range. These frequencies are pretty good at travelling through the materials that make up your home (brick, stone, wood, etc.) but, each wall encountered will reduce the signal strength and hence the usable range of your Wi-Fi network.
Later Wi-Fi standards introduced 5GHz Wi-Fi, which has much more bandwidth but these frequencies cannot pass through walls and other materials as well. 5GHz Wi-Fi has a shorter range than 2.4GHz of the same power. This is good because neighbours on 5GHz Wi-Fi are less likely to interfere with your network. It is bad because if you are even a short distance away from your own Wi-Fi access point, speeds will drop off quite quickly.
Many devices are 'dual band' and can use both 2.4Ghz and 5GHz Wi-Fi (assuming the access point supports both) but the act of switching between the two frequencies can sometimes be problematic. The 'hand over' between the two should be quick and seamless but this is not always the case.
Older devices with 2.4GHz Wi-Fi only can occasionally be difficult to a dual-band access point and many smart home device only use 2.4GHz because of its simplicity, lower cost chipset and improved range.
Each Wi-Fi frequency band (e.g. 2.4GHz and 5Ghz) is split into channels (Wikipedia overview). The set of channels used and the power levels allowed varies around the world but there are many common channels.
To guarantee no interference in any circumstances the Wi-Fi protocol requires 16.25 to 22MHz of channel separation and the remaining 2 MHz gap is used as a 'guard band' to allow sufficient attenuation along the edge channels. This essentially limits the number of usable bands and in the UK, you will mostly see access point configured to use channels 1, 6 and 11, to minimise the possibility of interference.
Depending on the size of your property, a single Wireless Access Point (WAP) may not provide reliable, high-speed Wi-Fi connectivity throughout your home and garden. Typically, some way of 'extending' the reach is required and this can be achieved in various ways:
Using of secondary AP is similar to using wireless repeater in repeater mode, but with a direct wired connection to the home network. The main advantages are that it is very easy to implement and configure and the throughput is not decreased like it is with a wireless repeater. The main disadvantage is the need for a wired connection to it, especially as it is likely to be placed at the other end of your home.
A Wi-Fi repeater or extender is used to extend the coverage area of your Wi-Fi network. It works by receiving your existing Wi-Fi signal, amplifying it and then re-transmitting the boosted signal. The disadvantages of this approach are that it significantly reduces the speed of your Wi-Fi and lowers the reliability of it.
Mesh Wi-Fi or Whole Home Wi-Fi systems consists of a main router/modem and a series of satellite nodes, placed around your house for full Wi-Fi coverage. They are typically all part of a single wireless network and share the same SSID and password. Most provide dual-band (both 2.4GHz and 5GHz) functionality.
Mesh systems use an additional 5GHz radio to connect mesh nodes together. This is not ideal for best performance, especially if the nodes are not close enough to communicate at their highest speeds. It also means that you have added another 5GHz radio in your home, in close proximity to the ones your client devices are using and this will introduce some level of interference. Using wired connectivity between mesh Wi-Fi nodes ensures maximum performance and reliability but not all mesh systems support this capability.
Sometimes you find a Wi-Fi connected product that simply refuses to connect to a dual-band access point. Our Tittle Light is one such example. In order to connect this to our network, we resorted to the secondary access point approach.
Understanding how you home network is working and being used is a key part of making it work reliably. There are a number of tools that can be used but, our favourite for diagnosing Wi-Fi issues is the WiFi Analyzer Android app, which supports both 2.4GHz and 5GHz (assuming the device you run it on also does).
We recommend that you avoid using Wi-Fi for smart home features as much as possible. Whilst it can work well up to a point, there are too many external factors that could potentially impact of your smart home operation. It should be limited to smartphones, tablets and those devices that have to use Wi-Fi (voice assistants, connected scales, etc.).
Wi-Fi should not be used for "IoT type" sensors because of the reliability, range, scalability and battery issues previously mentioned.
Wi-Fi should be avoided for 4K streaming and other bandwidth intensive appplications, whenever possible. Using it in this way will impact on all of the other Wi-Fi connected devices in your home. Smart TVs should be connected using Ethernet cables to get the best performance and reliability.
One of the things we see most often in online forums and on social media is people complaining about slow Wi-Fi in their home and how an Internet speed testing service is giving really poor results. Many people fail to make the distinction between their Internet connection and their Wi-Fi connection and don't realise that they are two separate sections of network. There is only one proper way to perform a speed test.
Wi-Fi is continually evolving and advancing and one of the key areas is in using less power for IoT devices.
