A wireless telecommunication system comprising a terminal device, a first network access node and a second network access node, wherein the first and second network access nodes are configured to support a dual connectivity mode of operation for the terminal device in which the first network access node acts as a master network access node and the second network access node acts as a secondary network access node and in which the same data are communicated between the terminal device and the first network access node and between the terminal device and the second network access node.