To be able to surf on your mobile unit you need to attach a subscription for data traffic to your standard subscription to prevent a unnecessarily high cost.
On the university we use AllTele, they offers following packet of data traffic tied to subscriptions in Telia's net:
If you use up all of your assigned data amount you will not be charged extra, but the speed will be significantly slower until next month. Note that all prices applies to data traffic in Sweden.
If you are about to go abroad with your phone there is some things to be considered so your subscription not will be charged high costs. Read more on the page Utlandsvistelse.