There are a few requirements based on what you are trying to do, but needing a 5mb connection isn't one of them to make a slingcatcher work. I've ran my slingcatcher at one point with a 500kbps upload speeds ( video settings 320 X 240 ) from my slingbox. Not the best picture, but it still worked. I would recommend, if at all possible, at least a 1mb or over upload connection from your internet service provider in Denmark and a download speed to match that ( if not more ) in Cambodia to receive a good enough picture on that end. Stabillity of the stream on both ends and latency ( based on the quality of your ISP and the distance from Denmark to Cambodia ) could be a factor, but anything close to a 1mb upload stream while remote viewing from your slingbox to your slingcatcher should work and have acceptable picture quality, but do try to get the fastest upload speed possible in Denmark and one that offers a stable consistent connection from your internet service provider to stream to cambodia; it'll make all the difference and allow you to bump up the picture settings to 640 X 480 which will look much better on your TV screen in Cambodia. Slingbox Pro HD could do a 1280 X 540 setting, but not quite that easy to do when streaming that far of a distance and with limited upload bandwidth.
"A home network that supports consistent 5 Mbps wired/wireless connection between your PC, router, and SlingCatcher
P.S Just to address those above specs. What they are talking about is the overall speed of your LAN ( local network ). Pretty much any router and P.C is capable of a speed of 5mb's. Wireless G can do up to 54mb's, so you're covered as far as specs with any computer and router made in the last decade, so bandwidth isn't the problem. What your entire situation is based around is remote viewing which puts the dependency on your ISP providers in Denmark and Cambodia to get the most stable and fastest speeds you can find to get the best picture out of the slingcatcher.
What I understand from your post, is that you would like to know what is the minimum bandwidth for SlingCatcher to streaming video from your Slingbox.
In this case, I would recommend to check the following links which will provide information about the main Tech Specs and requirements.