Depending on how long you plan to be there, I would investigate the cost of getting your own broadband; Even if the network has been set up well, you'll never get great gaming out of a heavily shared connection because of all the contention from other people.
If WiFi is your only option I have always found the best option is to find out exactly where your signal is strongest and pop in a proper external antenna that runs off a PCI card, preferably Intel but the card is not as important as the external antenna. USB adapters are too small to have decent antennas in them, they should be avoided if you aren't getting a strong signal.
If you can talk to the building manager to find out where the nearest access point is, then a directional antenna will make a big difference once aligned. I have onl ever used the flat plate-style antennas which are a PITA to align for the best signal but that hawking dish thing that Ryu linked looks like a more tolerant and user-friendly piece of kit.
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