[originaltext] AT & T plans to spend 18 billion dollars in 2019 upgrading it

AT & T plans to spend 18 billion dollars in 2019 upgrading its wireless networks to handle the increasing amount of new traffic. This is roughly 2 billion dollars more than the company had invested last year. Specifically AT & T will add 2000 new cell sites and upgrade existing cell sites with 3 times more fiber links than it had in 2009. This will increase capacity to connect the cell towers to AT & T’s main network. AT & T, which is the only wireless operator in the US selling iPhone, had been a target of much criticism over this past year as many iPhone users, particularly in big cities have complained about dropped calls, slow Internet access and poor service. Some critics claimed the company has not been spending enough on network upgrades to keep up with growing demand. AT & T has admitted that it has faced some difficulties particularly in big cities, but the company is closing the gap.
3. What will the 18 billion dollars be used for?
4. Where does AT&T face difficulties in particular?