Managing network access based on ranging information

Methods, systems, and apparatus for restricting use of a network element outside an authorized location range are disclosed. In one aspect a method includes obtaining, for a network element of a passive optical network, an identifier and ranging information corresponding to a present location of the network element; identifying, from a database and based on the identifier of the network element, stored ranging information specifying a previous location of the network element; determining, based on a comparison of the ranging information with the stored ranging information, that the location of the network element has changed more than a specified amount; and outputting an alert in response to determining that the location of the network element has changed more than a specified amount.