Massive MIMO (MaMIMO) is a new technology which is expected to play a part in the fifth generation (5G) mobile networks currently under development. It involves a very large number of antennas at the base station, serving many users simultaneously in the same spectrum. Distributed massive MIMO (D-MaMIMO - also known as "cell-free" massive MIMO) distributes these antennas at access points (APs) across the service area, providing better service to users at what would otherwise be the cell edge. It also has the advantage of bringing the APs closer to the users, and thus enabling ultra-low latency communications (i.e. with transmission delays of 1 ms or less), another important goal of 5G. The project will investigate both the performance of this system, using simulation and analytical tools such as stochastic geometry and network information theory, and also issues raised by the practical implementation of the technology, including the capacity of the "fronthaul" connections between the APs and the core network.