Hi Sue. My name is***** you for your question and the opportunity to assist. Every consumer grade wireless router provided by an internet service provider operates at 2.4Ghz. Some also operate at both the 2.4Ghz and 5Ghz bands. I know of no consumer product that operates soley at 5Ghz. That being said, you won't go wrong purchasing a 2.4Ghz product. In your situation with having to send a wireless signal upstairs I would recommend purchasing a powerline product to upgrade the wireless signal. The way these devices work is by using your electrical wiring to send the internet signal upstairs to a second adapter that then broadcasts the signal wirelessly in that area. These kits have two components. The first plugs into a power outlet by your TalkTalk router and is connected to it via a supplied network cable. The second adapter of the set is plugged into a power outlet in the area with a weak signal. The second adapter contains it's own wireless radio and provides a strong signal in the area in which it is located. I do not recommend using a signal booster that only connects wirlessly to your router. These devices do a poor job of sending wireless signals to upstairs areas. Below is an example of a powerline kit that would meet your needs:-http://uk.tp-link.com/products/details/?categoryid=2244&model=TL-WPA281KIT#spec-Please let me know if you need more clarification. I will always do my best to answer your question. Your satisfaction is my top goal. If you are not satisfied with the answer I provide, for any reason, please allow me to continue to help you (or recommend you for another expert or refund) rather than giving a negative rating. A positive rating is always appreciated.