Splitter and wireless router

We have two desktops, two laptops, and an Xbox all running off of one cable connection. The laptops and Xbox run off of a wireless router. In an effort to find a way to equalize the bandwidth usage amongst the devices I added a splitter between the wireless router and the desktops in the hopes that this would allow all of the devices to get an equal share of the bandwidth (15Mbps/2Mbps). The problem that keeps occurring is that the main computer connected to the wireless router always has a connection, however, the other desktop and laptops will seemingly lose connectivity at times. I say seemingly because the computers will show that they are connected but they cannot navigate the web, find servers, etc. This is remedied by restarting the computer or laptop. I need to know why the connectivity is being lost, what set-up is best for the items we have, and how to insure that all can be run at the same time without lag or loss of usage. Thank you for any ideas and help you can give me with this problem.

 

Please disregard this post since it is now apparent that the splitter option was not a viable one and that I was sold something I did not need from a less than reputable salesman. I am returning the splitter and will contact my internet provider when the problem occurs again, per their statement.