You can also start by making sure you're in all the meetings with other teams where your project and their project meet. Ask pointed questions in those meetings to gain understanding. Be friendly and courteous and helpful and they'll make sure you are in those meetings from now on. From there you'll get invited to other meetings that may be only slightly adjacent to your project. Again, be friendly, courteous and helpful. You will eventually get known for being someone with understanding and you'll find yourself in some rather important meetings after that.