do you have the exact model number of the device
you may be able to use a powerline which uses the electrical wiring to transfer the signal
so you plug one end into a socket near the router with a LAN cable connected to the router
and then another one plugs into a socket on the 4th floor and you can get a wireless option - although never used
you could also use an extender on 2nd floor
If you have a laptop wireless enabled - try using xirrus (see below) - see below to map out the signal strength - for an extender to work - it needs to be in an area where its getting a good signal - I would suggest -50 to -60 on the xirrus - BUT the signal must not fluctuate below -70 - hence the graph is useful to monitor for a few minutes
need the exact model to see how to apply security - but you probably need to connect to the unit and then using its IP address you log into the configuration pages and add the wireless security
it should use IP address assigned from your homehub - add mac address to the home hub , although that can be overcome - it will stop the casual user
you may be able to use a powerline which uses the electrical wiring to transfer the signal
so you plug one end into a socket near the router with a LAN cable connected to the router
and then another one plugs into a socket on the 4th floor and you can get a wireless option - although never used
you could also use an extender on 2nd floor
If you have a laptop wireless enabled - try using xirrus (see below) - see below to map out the signal strength - for an extender to work - it needs to be in an area where its getting a good signal - I would suggest -50 to -60 on the xirrus - BUT the signal must not fluctuate below -70 - hence the graph is useful to monitor for a few minutes
need the exact model to see how to apply security - but you probably need to connect to the unit and then using its IP address you log into the configuration pages and add the wireless security
it should use IP address assigned from your homehub - add mac address to the home hub , although that can be overcome - it will stop the casual user