I don't believe they keep records of browsing history as such and even if they did it would probably require legal intervention to obtain it. I could be wrong about that however I have never seen any information suggesting this information can be obtained. Have you deleted the history on your device and need to find a specific site or do you need this info for legal reasons or such?
All Telco's now keep a record of the IP addresses you visit for two years. So if you visit www.optus.com.au then their IP address will be logged (e.g. 220.127.116.11). However what articles you looked at or what you downloaded etc. is not kept.
This info is not something you can request though.