Here is what I intend to do, my family predominately uses a LAN cable to connect to the BSNL data one connection via a standard modem. I have bought a wifi router and I plan to create wifi network which should have good signal on 1st and 2nd floor. I am planning to keep modem on second floor and the router on first floor. The modem will be connected to the router via a lan splitter and a 20 foot long cable. I am using the splitter so that I can use the other port to connect to a desktop.
1) Will the lan splitter decrease my internet speed in any which way?
something like this...
2) Will the 20 foot cable decrease the speed in any which way?