Just a little note today on the availability of ITU standards. While I don't need them often, every now and then they are a great help to find the answer to some really nitty gritty circuit switched telecommunication network questions, both fixed and mobile. Most of them are available from the ITU web page. Not quite as open as 3GPP standards, i.e. the latest updates and additions seem to require some form of registration and/or payment, but for most purposes it should do.