1. Introduction
When users select and purchase wireless routers, 2.4G and 5G words often appear in the parameters; Or when connecting to Wi-Fi, we occasionally see that two Wi-Fi signals have the same prefix name, but 2.4G and 5G are marked at the end of the name. So, what is the difference between 2.4G and 5G in wireless routers? What are the two scenarios? This article will introduce this in detail.
2. What are 2.4G and 5G in wireless router
2.4G and 5G are commonly used in wireless routers. The unit is Hz (Hz), which is used to represent the working frequency of wireless signals. They respectively represent that wireless routers can transmit and receive signals in the 2.4GHz and 5GHz frequency bands. The 2.4G and 5G of wireless routers can be simply understood as signals in two different frequency bands. It is worth noting that 5G in wireless routers is not the same concept as 5G commonly used in mobile communications. The latter’s G is the abbreviation of Generation, representing the fifth generation mobile communication technology (5G for short).
According to the difference of support for 2.4G and 5G, wireless routers can be divided into single-frequency routers and dual-frequency routers. Single-frequency wireless router refers to the device that only has 2.4G wireless module and can only work in the 2.4GHz wireless frequency band. When using this kind of device, users can only search 2.4G Wi-Fi signal. The dual-band router is a device that has both 2.4G and 5G wireless modules and can work in two band modes at the same time. When using this kind of device, users can set the wireless mode in the 2.4GHz or 5GHz band. Compared with single-frequency router, dual-frequency router can provide higher transmission rate and stronger stability.
3 . Difference between 2.4G and 5G
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Working equipment
Single-band wireless routers can only use the 2.4GHz band, while dual-band wireless routers can work in the 2.4GHz and 5GHz bands at the same time.
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Operating frequency band
The operating frequency of 2.4G signal is between 2.4GHz and 2.4835GHz.
The working frequency of 5G signal is between 5.150GHz and 5.850GHz. This frequency band is divided into 201 sub-channels. The effective bandwidth of each channel is also 20MHz, but there is no overlap between each adjacent channel.
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Signal bandwidth
The standard bandwidth of each channel in the 2.4G and 5G frequency bands is 20MHz. 2.4G can expand the bandwidth to 40MHz, and 5G can expand to 40MHz, 80MHz and even 160MHz.
Wireless transmission rate is an important index to evaluate network performance, which is mainly affected by space flow, signal bandwidth, QAM modulation mode and coding rate. As can be seen from Table 3-1, with the upgrading of wireless standards, various underlying coding, channel bandwidth and space flow technologies have been greatly improved, making a qualitative leap in the theoretical maximum rate that can be supported. Under the same 802.11ax protocol standard, since the bandwidth supported in the 5G band can reach 160MHz, while 2.4G only has 40MHz, the theoretical maximum speed of the 5G band can reach 9.6Gbps, while 2.4G can reach 2.3Gbps at most.
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Coverage
The essence of wireless signal is electromagnetic wave. The wavelength of electromagnetic wave is inversely proportional to the frequency, which means that the wavelength of 5GHz signal is less than 2.4GHz. The shorter the wavelength is, the stronger the signal penetration is. Therefore, when encountering obstacles, most of the signals will directly penetrate the obstacles, while only a small part of the electromagnetic waves will reflect or diffract. However, the signal needs to consume a lot of energy when it penetrates the obstacle, and the energy is often consumed when it does not penetrate the obstacle. Therefore, on the receiving end on the other side of the obstacle, there are few signals that can be directly penetrated, and more signals that can be transmitted by reflection or diffraction around the obstacle are received.
Therefore, when a 5GHz signal encounters an obstacle, almost all of its energy is used for penetration, which will cause a large amount of energy loss. Therefore, the signal attenuates greatly in the process of transmission, resulting in poor signal penetration ability and smaller coverage; However, due to the long wavelength and weak penetration of 2.4GHz signal, more signals can only continue to propagate through reflection and diffraction to bypass obstacles, and the signal attenuation is smaller in the process of propagation, so the signal has better wall-penetrating ability and larger coverage distance.
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Anti-interference capability
The sources of interference are mainly the interference generated by the overlapping of wireless channels and the same frequency interference caused by other applications in the same frequency band.
○ Interference between wireless channels
The adjacent channels of the 2.4G frequency band overlap during the division of subchannels, resulting in interference between wireless channels and affecting the stability of wireless transmission. However, each channel in the 5G band does not overlap, so there is no inter-channel interference.
○ Same frequency interference
In addition to wireless LAN Wi-Fi, Bluetooth, RFID, ZigBee and other technologies all use 2.4G as the working frequency band, and a variety of medical RF equipment all work in the 2.4G frequency band, so there is a lot of co-frequency interference.
In the 5G band, at present, only satellite radio measurement service and satellite fixed service are used, and no other daily household equipment except wireless router occupies this band, so it is not vulnerable to co-frequency interference.
To sum up, the anti-interference ability of 5G signal is better than 2.4G, so the network speed is more stable.
2.4G has the advantages of large coverage and strong wall-penetrating ability, but the transmission rate and anti-interference ability are poor. Therefore, 2.4G is suitable for scenarios where users have a large mobile range, many obstacles such as walls, and few access devices. 5G is complementary. There are fewer devices using 5G frequency band, the wireless environment is cleaner, the interference is less, the network is more stable, and supports higher wireless transmission rate. However, the attenuation of 5G signal during transmission is greater, and the coverage and wall-penetrating ability are inferior to 2.4G. Therefore, 5G can play a better role in the scenario of fewer obstacles and more wireless access devices. For domestic wireless routers, when the mobile device and the router are in the same room, it is suitable to use 5G signal; If there are multiple walls, 2.4G is more appropriate.
2.4G and 5G have their advantages and disadvantages. Users can choose to access 2.4G or 5G Wi-Fi signals according to their needs. However, in order to solve the problem of manual handover of users in complex network environments, wireless routers from Ruijie and other manufacturers all support the automatic handover technology of duplex routing. 2.4G and 5G are combined into one signal. Using the same SSID (network name), the device will automatically switch to the best Wi-Fi network according to the strength and quality of the two signals. Users can enjoy the best experience of 2.4G and 5G without manual switching.
