2.4 GHz radio use

Some Baby monitors use the 2.4 GHz band. Some transmit only audio but others also provide video.

Wireless microphones operate as transmitters. Some digital wireless microphones use the 2.4 GHz band (e.g. AKG model DPT 70).

Wireless speakers operate as receivers. The transmitter is a preamplifier that may be integrated in another device. Some wireless speakers use the 2.4 GHz band, with a proprietary protocol. They may be subject to dropouts caused by interference from other devices.

Video senders typically operate using an FM carrier to carry a video signal from one room to another (for example, satellite TV or closed-circuit television). These devices typically operate continuously but have low (10 mW) transmit power. However, some devices, especially wireless cameras, operate with (often unauthorized) high power levels, and have high-gain antennas.

Amateur Radio operators can transmit two-way Amateur television (and voice) in the 2.4 GHz band—and all ISM frequencies above 902 MHz—with maximum power of 1500 watts in the US if the transmission mode does not include spread spectrum techniques.[11][12] Other power levels apply per regions. In the UK, the maximum power level for a full licence is 400 watts.[13] In other countries, maximum power level for non-spread-spectrum emissions are set by local legislation.

Although the transmitter of some video cameras appears to be fixed on one frequency, it has been found in several models that the cameras are actually frequency agile, and can have their frequency changed by disassembling the product and moving solder links or dip switches inside the camera.

These devices are prone to interference from other 2.4 GHz devices, due to the nature of an analog video signal showing up interference very easily. A carrier to noise ratio of some 20 dB is required to give a "clean" picture.

Continuous transmissions interfere with these, causing "patterning" on the picture, sometimes a dark or light shift, or complete blocking of the signal.

Non-continuous transmissions, such as Wi-Fi, cause horizontal noise bars to appear on the screen, and can cause "popping" or "clicking" to be heard in the audio.

Video senders are a big problem for Wi-Fi networks. Unlike Wi-Fi they operate continuously, and are typically only 10 MHz in bandwidth. This causes a very intense signal as viewed on a spectrum analyser, and completely obliterates over half a channel. The result of this, typically in a Wireless Internet service provider-type environment, is that clients (who cannot hear the video sender due to the "hidden node" effect) can hear the Wi-Fi without any issues, but the receiver on the WISP's access point is completely obliterated by the video sender, so is extremely deaf. Furthermore, due to the nature of video senders, they are not interfered with by Wi-Fi easily, since the receiver and transmitter are typically located very close together, so the capture effect is very high. Wi-Fi also has a very wide spectrum, so only typically 30% of the peak power of the Wi-Fi actually affects the video sender. Wi-Fi is not continuous transmit, so the Wi-Fi signal interferes only intermittently with the video sender. A combination of these factors - low power output of the Wi-Fi compared to the video sender, the fact that typically the video sender is far closer to the receiver than the Wi-Fi transmitter and the FM capture effect means that a video sender may cause problems to Wi-Fi over a wide area, but the Wi-Fi unit causes few problems to the video sender.

Many video senders on the market in the UK advertise a 100 mW equivalent isotropically radiated power (EIRP). However, the UK market only permits a 10 mW EIRP limit. These devices cause far more interference across a far wider area, due to their excessive power. Furthermore, UK video senders are required to operate across a 20 MHz bandwidth (not to be confused with 20 MHz deviation). This means that some foreign imported video senders are not legal since they operate on a 15 MHz bandwidth or lower, which causes a higher spectral power density, increasing the interference. Furthermore, most other countries permit 100 mW EIRP for video senders, meaning a lot of video senders in the UK have excessive power outputs.

Many radio-controlled drones, model aircraft, model boats and toys use the 2.4 GHz band. These radio systems can go up to 500 meters in R/C cars and over 2.5 kilometres (1.6 mi) in drones/airplanes.

Some garage door openers use the 2.4 GHz band.

Some Smart Power Meters use the 2.4 GHz band.

Some new truly wireless power transmission uses the 2.4 GHz band.

It is better to use Ethernet or maybe PLC when Wi-Fi can be avoided (but beware of power surges, they may happen through any conductive cable).

A general strategy for Wi-Fi is to only use the 5 GHz and 6 GHz bands for devices that also support it and to switch off the 2.4 GHz radios in the access points when this band is not needed anymore.

Often solving interference is as simple as changing the channel of the offending device. Particularly with video senders, whereby plugging in the receiver with no transmitter attached will let you "see" the neighbour's video sender, this technique is considered part of the "Installation process". Where the channel of one system, such as a Wireless ISP cannot be changed, and it is being Interfered with by something such as a video sender, the owner of the video sender is normally very happy to assist with doing this, providing it is not too much work. However the problem comes when the interference is something such as a wireless CCTV camera which is mounted on a chimney and requires a long ladder to access. Such cameras, due to their height, cause serious problems across a wide area.

Another cure is to offer an alternative product to the owner free of charge. Typically this would be a wired camera, which normally have far better performance than wireless cameras anyway, a cable to replace the video sender, or an alternative video sender which has been hard-wired to an alternative channel, with no means of changing it back to the offending frequency.

Yet another cure is to move from 2.4 GHz to another frequency which lacks the vulnerability to interference inherent at that frequency, for example the 5 GHz frequency for 802.11a/n.

If a device using a proprietary protocol is causing or suffering interference, replacing it with another one using a different communication scheme (proprietary or standard) might solve the problem.

In extreme cases, where the interference is either deliberate or all attempts to get rid of the offending device have proved futile, it may be possible to look at changing the parameters of the network. Changing collinear antennas for high gain directional dishes normally works very well, since the narrow beam from a high gain dish will not physically "see" the interference. Often sector antennae have sharp "nulls" in their vertical pattern, so changing the tilt angle of sector antennas with a spectrum analyzer connected to monitor the strength of the interference can place the offending device within the null of the sector. High gain antennas on the transmitter end can "overpower" the interference, although their use may cause the effective radiated power (ERP) of the signal to become too high, and so their use may not be legal.

Interference caused by a Wi-Fi network to its neighbors can be reduced by adding more base stations to that network. Every Wi-Fi standard provides for automatic adjustment of the data rate to channel conditions; poor links (usually those spanning greater distances) automatically operate at lower speeds. Deploying additional base stations around the coverage area of a network, particularly in existing areas of poor or no coverage, reduces the average distance between a wireless device and its nearest access point and increases the average speed. The same amount of data takes less time to send, reduces channel occupancy, and gives more idle time to neighboring networks, improving the performance of all networks concerned. However, there is a maximum number of base stations that can be added, after which they disrupt the network more than that they help: any additional capacity is then sapped by control traffic.[15]

The alternative of increasing coverage by adding an RF power amplifier to a single base station can bring similar improvements to a wireless network. The additional power offered by a linear amplifier will increase the signal-to-noise ratio at the client device, increasing the data rates used and reducing time spent transmitting data. The improved link quality will also reduce the number of retransmissions due to packet loss, further reducing channel occupancy. However, care must be taken to use a highly linear amplifier in order to avoid adding excessive noise to the signal.

All of the base stations in a wireless network should be set to the same SSID (which must be unique to all other networks within range) and plugged into the same logical Ethernet segment (one or more hubs or switches directly connected without IP routers). Wireless clients then automatically select the strongest access point from all those with the specified SSID, handing off from one to another as their relative signal strengths change. On many hardware and software implementations, this hand off can result in a short disruption in data transmission while the client and the new base station establish a connection. This potential disruption should be factored in when designing a network for low-latency services such as VoIP.