How to Identify and Reduce Wireless Signal Interference

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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.

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
• Certain external electrical sources such as power lines, electrical railroad tracks, and power stations
• Wi-Fi Cameras
• Baby Monitors
• 2-Way Radios
• Unshielded power or video cables

It is also possible to have interference from construction materials used in the building you are in (Table 1). The following chart may assist with placement of the router and devices:
 

Material	Interference	Sample Use
Wood/wood paneling	Low	Inside a wall or hollow door
Drywall	Low	Inside walls (every wall between the router and the wireless device degrades the signal more)
Plaster	Low	Inside walls (Without wire mesh)
Furniture	Low	Couches or office partitions
Clear glass	Low	Windows
Tinted glass	Medium	Windows
People	Medium	High-volume traffic areas that have considerable pedestrian traffic
Ceramic tile	Medium	Walls
Concrete blocks	Medium/high	Outer wall construction
Bricks	Medium	Walls
Marble	Medium	Counter Tops
Mirrors	High	Mirror or reflective glass
Metals	High	Metal office partitions, doors, metal office furniture
Water	High	Aquariums, rain, fountains

Table 1: Construction Materials

Besides competing signal interference, other hardware and even natural environmental elements can interfere with signal reception/transmission. Some common, and not so common environmental factors to consider are these:

• Electrical Load Centers (Fuse boxes or electrical conduits)
• Metal panels/sheeting in the roof or walls, including stucco lathe in exterior walls
• Pine Trees
• Sunspots/Solar activity

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. To increase wireless bandwidth, it will be necessary to keep interferences in mind while setting up your work space.