Time for a new router if you want increased wireless speeds. Many newer routers are available with mesh points to provide solid coverage throughout the house. Below is the Google result for your router. Max speeds are rarely achieved.

The N150 router is compatible with IEEE 802.11b/g/n standards, and the maximum speed that you can get with WRT120N is 150 Mbps.

https://routerchart.com/linksys/link...20n-wrt120n-68