• Proximity to wireless access points: the closer you are to a wireless access point, the more likely you are to receive a strong signal.
• Total number of users and total amount of traffic: Wi-Fi is a shared medium, which results in many wireless devices competing for a set amount of available bandwidth. The number of users and amount of traffic on NDSU's wireless network peaks during regular operating hours (8 a.m. to 5 p.m., Monday through Friday). For this reason, IT recommends connecting to the wired network when transferring large data files or streaming long videos,  particularly during peak traffic hours.
• Sources of radio frequency interference: radio frequency interference involves the presence of unwanted radio signals that disrupt access to the wireless network. Potential sources of RF interference include cordless phones, Wi-Fi enabled printers, wireless cameras, Bluetooth devices, wireless game controllers, wireless audio headsets, and computer peripherals (e.g., wireless mice and keyboards). RF interference can also be caused by other devices, such as florescent lighting and microwave ovens.
• Sources of passive wireless interference: passive wireless interference can be caused by some construction materials, furniture, and home decor items. These materials can absorb or obstruct a wireless signal.

Wireless Interference

1. Unauthorized Wireless Devices: one major interference source is unauthorized wireless devices, most commonly wireless routers. These devices can disrupt the service for neighboring wireless access points. They also pose a security risk and are in violation of acceptable use policy. The IT Division will detect and disable unauthorized wireless routers. Using a computer or other device to create an ad-hoc wireless network, where the device acts as a relay for other devices to connect to the Internet, is also against acceptable use policy. We recommend disabling this feature because both the host ad-hoc device and all connected devices will have a much slower connection.
2. Cordless Phones: cordless phones operate on many different frequencies. You can typically find out which frequency your phone uses by simply reading the labels. They include the following: 900MHz, 2.4GHz and 5.8GHz. A computer using Wi-Fi may have connection problems if anyone is using a 2.4GHz phone in the area.
3. Microwaves: microwave ovens can also cause interference with Wi-Fi devices. If a computer within 10 feet of an operating microwave is experiencing slow connection, consider relocating one of the devices.
4. Bluetooth: devices that are Bluetooth-capable, including laptops, smartphones, keyboards and mice, can also interfere with Wi-Fi access.
5. Construction materials, furniture and home decor items: items consisting of metal or plaster with embedded mesh (e.g., furniture, metal decor, lighting, appliances) cause very high levels of interference. Items consisting of paper or heavy fabric (e.g., books, draperies, posters) cause high levels of interference. Items consisting of glass (e.g., glass decor, windows) cause medium levels of interference. Items consisting of wood or sheetrock (e.g., walls, wood furniture) cause low levels of interference.

Tips for minimizing potential interference

• If possible, avoid using devices that operate in the following frequency ranges used by 802.11:
• 2.40 - 2.485 GHz
• 5.18 - 5.6 GHz
• 5.68 - 5.86 GHz
• Use 5 GHz wireless options whenever possible. You will find this option for both 802.11a and 802.11n. Using this band will provide better performance by limiting the potential of interference as well as having more non-overlapping channels. (Note: Not all devices support 5 GHz. For assistance, contact the IT Help Desk.)
• If wireless performance in your room or office is inconsistent or poor, consider whether other devices or construction materials in close proximity may be interfering with your wireless connection. Simply moving your wireless device to an alternative location in that space may provide better connectivity.
• Turn off Wi-Fi on your cell phone if you are using cellular for your data connection.