 Hi, welcome to week 2. By now I hope you are all familiar with the platform. You heard the lectures, learned how to use the various features of the platform, posted a query, comment, answered some questions and learned something. So what do we have in week 2? Week 2 has four sets of lectures. In the first set I am going to talk about the various kinds of mobile access devices there are. We have simple phones, these are called feature phones or dumb phones. We have smart phones, we have phablets and tablets, there is a lecture talking about different aspects and properties of these devices. We have a very nice lecture by Sumit Kallra on Android, Android is the operating system on mobile phones. He will explain to you what Android is and its various versions and so on. And there are set of wonderful lectures by Navpreet Singh who will talk about networks, local area networks, metropolitan networks, wide area networks, how the internet works when you type a URL in the browser what happens is going to explain all this. And then we are going to have a set of lectures by Aditya Jagannatham on communication networks. You know our phone connects with the internet or even a voice call over using 2G, 3G and so on. What are these things? How much data flows over a 3G network? He is going to explain this kind of stuff. And early next week we are going to have a quiz, do not get worried it is going to be a simple multiple choice kind of exam there will be a set of questions it will be fun. You can use this quizzes to consolidate your learning. You can use this quiz to test yourself if you know the important things in this space. Quizzes are not to test you guest they are also to tell you what is important in that area. Have fun.