Abiding Geocast is a time stable geocast scheme used in ad hoc networks or in cellular networks. Messages are delivered to all nodes that are inside a destination region within a certain period of time. In contrast to an ordinary geocast, which is delivered to all nodes which are inside a destination region exactly at the time of sending plus distribution delay in the network, abiding geocast allows senders to define a lifetime for the geocast message.
Abiding geocast is created by the retransmission of the geocast message, either periodically to the destination region or whenever a node inside the destination region detects a new neighbor.
New services and applications such as position-based advertising, position-based publish and subscribe use abiding geocast. In the future, abiding geocast in the automotive industry may enable vehicles to form a position-aware ad hoc network. Many necessary conditions are already in place: many vehicles are already equipped with a navigation system (i.e. are position-aware) and, triggered by the introduction of automatic toll systems, many will be equipped with communication systems in the near future (in many countries based on IEEE 802.11a). Abiding geocast enables the creation of virtual traffic signs such as local hazard warnings \cite{Maihoefer04bb}. For example, an abiding geocast fixed to a certain geographical area could warn approaching vehicles about an icy road.