Question

Question about network communications.

What is the cause of wireless radio frequency interference?

Why must we consider interference and noise when we want to make a reliable wireless communication system?

Answer 1

1.

Because the air is shared by all transmitters, transmissions by any device at the same frequency as an access point's radio can cause interference. Because 802.11 wireless networks operate in unlicensed bands used by many technologies, such as microwave ovens, video surveillance cameras, cordless phones, they are subject to interference. In addition, wireless access points sharing the same channel might interfere with each other. The effect of interference is highly dependent on the strength of the transmission and the distance from the interferer. Access points closest to and on the same channel as an interferer will be affected more than those that are further away.

These are some common causes of wireless interference:

• Leaving the channel number on each radio set to the default value can result in high interference among the radios because too many radios are sharing the bandwidth on one channel.
• Hidden nodes in a wireless network referring to nodes that are out of range of other nodes or a collection of nodes. A hidden node can generate a high number of cyclic redundancy check (CRC) code errors.
• Co-channel interference or adjacent channel interference can result from setting radios to bands that have overlapping channels. The channels might not all be in use by your network—neighboring company signals can also cause interference.
• Some non-network devices, such as microwave ovens, car alarms, cordless phones, or wireless video cameras can interfere with wireless channels. Most often, these devices are using the 2.4-GHz frequency.
• Bad electrical connections can cause broad RF spectrum emissions.

Point 2

With the increasing number of wireless devices in our environment, wireless signal interference becomes a concern for connection stability and overall performance, it is important to understand what causes interference so that you can effectively reduce interface and enhance wireless performance.

Therefore, there are many mitigation techniques concern in combating some of these issues, such as adaptive transmit power control (ATPC). ATPC use to decrease interference between link and other services, and to increase the link availability. Keywords: Adaptive transmit power control (ATPC), co-channel interference, fractional degradation in performance (FDP), terrestrial microwave link (TML), frequency sharing criteria, high power amplifier (HPA).

A solution to interference problems in wireless communication networks is interference alignment . In communication systems, noise is an error or undesired random disturbance of a useful information signal. ... While noise is generally unwanted, it can serve a useful purpose in some applications, such as random number generation . To reduce the interference on your wireless network, ensure that you are reducing the number of devices in the area. Additionally, you can attempt to use a different wireless channel that has less traffic.

Wi-Fi technologies can use both the 2.4 GHz or 5.0 GHz transmission bandwidths. Bluetooth only uses the 2.4 GHz transmission bandwidth.

Because these bandwidths are also shared by many household and office devices, relocation of some devices may be necessary to reduce competing device interference.

Some signs that you may be experiencing interference are:

• Intermittent wireless connections
• Unable to pair Bluetooth devices properly
• Slow performance on one device when another is being used
• Wireless signal strength decreases within normal ranges from the router
• Decreased download and upload speeds

It is possible to reduce the interface in your environment, if you are able to effectively isolate the cause(s) and take steps to reduce the interference.

To identify every device in your environment using the 2.4GHz and 5.0 GHz bandwidths, it will be necessary to check the specifications on every electronic device. Keep in mind that while they may not list the bandwidth, they are using these radio frequencies if they are noted to be "Bluetooth", "Wi-Fi" or "Wireless" devices. Here are some of the more common devices that can cause interference:

• Microwaves
• Cordless Phones
• Tablets
• Direct Satellite Service etc.