How to manage the way router shares traffic

I just came here from stackoverflow, hope it's the right place to ask this question.

We share internet in our apartment via a Linksys router (2 people are connected with wireless and 2 people with Ethernet cable). The channel is 15 Mbit, which should be enough, but when someone starts to download something on max speed, no one else can even open a web page. Is there a way to tell the router to share traffic among peers? Or it does not distinguish between connected computers and just redirects packets?

Another solution would be using a download manager with speed control but my roommates are lazy :)

Thank you.

From serverfault Piligrim

• Probably you can install DD-WRT firmware on your router. It has 2 types of QoS: HFSC and HTB

  

  It also has:

  • service based priority
  • mac based piority
  • ip based priority
  • port based piority
  Mecki : HFSC is broken in DD-WRT AFAIK (sometimes more, sometimes less, but they admit that in their own wiki and forum), thus everyone is highly recommend to use HTB until they finally fix this once and for all. Just a little tip (using DD-WRT myself at home)
  From SaveTheRbtz