Abstract: The presently disclosed subject matter includes, inter alia, a separation module being operatively connectible to a network device operable to facilitate data communication in a communication network, the separation module being configured to control data communication in the communication network, the separation module being assigned with a network-id associating the separation module with a given network environment; the separation module being further configured to tag a data packet received by the network device from a first direction, in order to associate the data packet with a given network environment; and determine whether a tag, associated with a data packet received by the network device from a second direction, is compatible with the assigned network-id, and if it is, remove the tag from the data packet and allow transmission of the data packet.

Abstract: A communication system comprising moving relay/s including base- and mobile-station functionality and a radio manager, all co-located, emergency moving relay/s further including a simulated stationary network that includes a simulated IP connectivity gateway communicating with a simulated mobility management entity and simulating the operation of a stationary network; the emergency moving relay being a root of a subtree including moving relay/s and mobile station/s, and utilizing its mobile-station functionality, base station functionality and radio manager for normal and emergency operation including communicating to a designated mobile station in the subtree each message received from a moving relay mobile in the subtree, the message having an IP address of the designated mobile station; or communicating to the simulated stationary network each message received from a moving relay/mobile station in the subtree and having an IP address not matching any mobile station in the subtree.