Since the 802.11n standard was launched in 2009, it is most normal to have a router that simultaneously uses two bands of Wi-Fi frequencies to provide connectivity, however, it was not until the departure of the Wi-Fi 5 standard that the Operators began to provide these types of routers that use 2.4GHz and 5GHz at the same time . We also know that as the simultaneous dual band, 2 Wi-Fi and even the 5GHz band is known as “WiFi Plus” as it provides better wireless performance in terms of speed.
Introduction to 2.4 GHz and 5 GHz networks
If you recently changed your router, your Internet provider will have provided you with one that includes both frequency bands. Generally, fiber optic customers two years and older have one of this type. An example of a dual band router are the two HGU models that Movistar provides to its clients, or the Livebox Fibra de Orange / Jazztel or the routers that Vodafone and Grupo Masmóvil provide to their clients.
Before we start, we have to comment that this has nothing to do with 2G, 3G, 4G or 5G mobile networks. Somewhere where there is public WiFi, you still find a sign that calls them 2.4G or 5G. So we wanted to clarify that concept, those G refer to the generation. Right now, in 2020 we are in full expansion of 5G or fifth generation networks.
However, when we talk about Wi-Fi, that G is related to radio frequency. In the case of 2.4G networks, it means that it emits its signal in the 2.4 Gigahertz (GHz) band. Then, on the other hand, we have 5G which means that the signal works in the 5 GHz band.
Next, I will briefly explain the 802.11 standard. So you can check and understand how our home routers have evolved in the last 20 years.
The 802.11 standard and how it has influenced the Wi-Fi speed of our routers
The 802.11 standard is a family of wireless standards created by the Institute of Electrical and Electronics Engineers. In this case, I will only comment on the ones that have been used the most in the routers that we have in our homes. Let’s briefly talk about the 802.11 a, b, g, n, ac and ax standards.
The 802.11a revision was approved in 1999. This standard operates in the 5 GHz band with a maximum speed of 54 Mbit / s. The data rate is reduced to 48, 36, 24, 18, 12, 9 or 6 Mbit / s if necessary. It has a range of 20 km with special radii. It has not been a standard that has been used in the routers that we have at home.
The next one that we are going to discuss is the 802.11b standard that was also ratified in 1999. The maximum transmission speed is 11 Mbps, and it works in the 2.4 GHz band. In practice, the maximum transmission speed with this Standard is approximately 5.9 Mbit / s over TCP and 7.1 Mbit / s over UDP. An example that some of you may have had at home is the Zyxel Prestige 650.
Next, in June 2003 the modulation standard was approved: 802.11g , we could consider it as an evolution of 802.11b. Like the latter, it operates in the 2.4 GHz band, but operates at a maximum theoretical speed of 54 Mbit / s. However, the average would be 22 Mbit / s of actual transfer speed. It should be noted that it is compatible with standard B and uses the same frequencies. An example of a router in this category would be the Zyxel Prestige 660HW-D1.
The next one that we are going to discuss is the 802.11n standard that was approved by the IEEE on September 11, 2009. Its theoretical maximum speed depends on the number of antennas and the amplitude modulation in square (64QAM by default, 256QAM or 1024QAM), so the maximum speed would be up to 1000Mbps if we use four antennas and 1024QAM modulation, since there have been no routers with more than four antennas.
In addition, it can work in the 2.4 GHz and 5 GHz bands. Thanks to this, 802.11n is compatible with devices based on all previous editions of Wi-Fi (a / b / g). An example would be the Comtrend VG 8050 router that Movistar put with the first fiber optic lines.
The most common currently is the 802.11ac standard that was ratified in July 2014. Also known as WiFi 5, Gigabit WiFi or popularly as WiFi 5G. This standard consists of improving transfer rates up to 433 Mbit / s per data stream, but if we use 1024QAM, we can achieve up to 540Mbps per data stream. Also, theoretically you could reach rates of 2100 Mbps using 4 antennas. In this case, an example of a WiFi AC router would be the FritzBox 7590.
Finally, mention the 802.11ax standard that is designed to operate in the 2.4 GHz and 5 GHz bands. It is also known as WiFi 6. In this case, we have quite important differences from the previous standards, now we have bidirectional MU-MIMO to increase overall network performance, OFDMA to allow connection of multiple devices and transmit simultaneously without loss of speed, power saving features, BSS Color to mitigate interference from neighboring Wi-Fi networks, and we even have high more wireless speed. In addition, in the 5GHz band we have 160MHz of channel width, to achieve speeds of up to 4.8Gbps with four antennas. This standard is the present and future of today’s Wi-Fi networks, and very soon we will see in a massive way operator routers that use Wi-Fi 6 or also known as 802.11ax.
The 2.4 GHz band, the beginning of everything
When we talk about the 2 WiFis, one of them is the 2.4GHz networks. Following the thread of the standards that we explained above, these would basically be those that can operate on our router in the 2.4 GHz band:
- 802.11b
- 802.11g
- 802.11n
- 802.ax
Depending on the standard used, we will have a higher speed or a lower speed, we must remember that we can achieve speeds between 11Mbps of the 802.11b standard, and up to 1148Mbps of the Wi-Fi 6 standard. Currently, they are operating exclusively in the 2.4 GHz band ( no 2 WiFi) there would be two kinds of equipment:
- The operators ADSL routers and almost any ADSL2 + router that we buy.
- The first fiber optic routers that have not yet been replaced by simultaneous dual-band (2 WiFi)
In this sense, it should be noted that it would be very strange to find a house with a router that did not comply with the 802.11n standard at least, although the most normal thing nowadays is that it supports the Wi-Fi 5 (802.11ac) standard.
The disadvantages of this frequency band is that we will only be able to use channels 1 to 13. The 2.4 GHz WiFi band works from 2,412 MHz (channel 1) to 2,472 MHz (channel 13), and we would have a new channel every 5 MHz, each Wi-Fi network occupies 20MHz of channel width, or 40MHz of channel width, so we would be occupying the entire electromagnetic spectrum available.
With so few channels, it will cause us to have a lot of interference with the networks of our neighbors. Since, for example, in a large city we will have many neighbors each with its 2.4 GHz Wifi. In addition, 2.4GHz Wi-Fi networks go further than 5GHz networks, so we will suffer from even more interference and packet loss. Choosing the Wi-Fi channel is critical in this frequency band, although normally the routers have activated an “Auto” mode that is in charge of analyzing the Wi-Fi networks around us, and they select an optimal automatic channel, based on the Wi-Fi 4 standard, this option is available in the vast majority of routers.
Logically, having little channel width and a lot of interference, the main drawback of 2.4 GHz networks is that the connection speed that we can achieve is much lower than that of 5 GHz . In general we could have an average maximum speed of about 100 Mbps.
The 5 GHz band, the fastest
Regarding those that have a 5 GHz band or 5G Wifi, they use the 802.11n standard if the router is very old, or directly the 802.11ac if it is one of the current ones. Currently there are already routers with Wi-Fi 6, but the operators have not yet taken the step to provide them to their customers, although it is a matter of time that it is a reality. As a general rule, it should be noted that these 5G WiFi routers are dual band so they also have WiFi 2.4.GHz.
One of the most positive points of these 5 GHZ Wifi networks is that they have more channels available, and 80MHz or 160MHz of channel width, so we will achieve high wireless transfer rates. For this reason, with a modern smartphone that supports 5 GHz networks, we can obtain speeds greater than 500 Mbps. Remember that in a 2.4 GHz one, the average is over 100 Mbps.
One way to check it would be with the free speed test app.
However, 5 GHz networks because of the frequency in which they emit, have a drawback and it is none other that supports the distance worse. When you leave the room where the router is, the signal starts to drop dramatically. Walls and mirrors are the great enemies of this type of network.
And why do we have 2 WiFi networks in our router?
Some of you may wonder why we have 2 WiFi networks. More than one would think that with the faster 5GHz network you would have enough. However, if you think carefully we find two fundamental reasons why we need to have 2 WiFis:
- Compatibility with older devices.
- Greater coverage within our home or workplace.
One reason for compatibility may be because you have a quality laptop that does not support the 5 GHz network because it has an older Wi-Fi card. Let’s suppose that what you use it for is powerful enough and you don’t have to buy another one. We would also have to talk about smartphones, although high-end ones have supported both bands for quite a few years, lower-range ones have not. However, those of medium-high range who buy for prices close to € 300 support it, but there are still models that do not.
For example, many lower midrange phones from two years ago can only connect to the 2.4 GHz band in b / g / n modes. Another situation that must be considered that currently in 2020 there are still mobiles that can only connect to 2.4G networks. These are entry-level mobiles that cost about € 100. As you can see, simply for compatibility, it is worthwhile to have dual band routers, fortunately for us that is the trend.
Now we are going to try the great virtue that 2.4 GHz networks offer us. That is nothing else that allows us to have a greater distance with the router even if we lose speed. For example, it may be the case that in an area you do not have WiFi 5 available, but you can use your 2.4 GHz network. A practical case, may also be the use of IoT devices (smart plugs, IP cameras, motion detectors and other home automation devices), the vast majority of them connect only to 2.4 GHz networks. One reason is that they require little bandwidth, and the other is that the distance from the router to which you can place it is much greater .
I don’t have two Wi-Fi networks but my router is dual band
Sometimes Wi-Fi routers are simultaneous dual band, but we will not see two different Wi-Fi networks when we are going to connect with our mobile or computer. The reason is that the router is internally configured with a single SSID (Wi-Fi network name) that is shared by both frequency bands (2.4GHz and 5GHz). This allows the router to have band-steering, and place the wireless device in the best available frequency band, ideal so that we do not have to worry about which SSID we connect to, we will only have one, and the router will take care of positioning us properly in the best available frequency band.
As you have seen, having the two frequency bands with 2 WiFi networks is necessary, each band must be used depending on your needs at all times. Thus the coexistence of both offers us more possibilities.
