Communication system and method

摘要

The application relates to a communication system comprising: a communication network; an access node connected to the communication network; at least one network node connected to the communication network, wherein the at least one network node does not control the access node; and a user terminal configured to establish a data connection with the access node, herein the user terminal is arranged to periodically generate a message at predetermined intervals and transmit the periodic message to the at least one network node via the access node over the communication network and receive responses to the periodic messages from the at least one network node; wherein the at least one network node is configured to determine that the data connection established between the user terminal and the access node is required to be terminated; the user terminal further arranged to analyse the responses received from the at least one network node to determine whether to terminate the connection to the access node, and, in the case that the connection to the access node should be terminated, transmit a disconnect message to the access node from the user terminal.