| 摘要 |
<p>Packets are transmitted between stations of an ad-hoc network of mobile stations by using routing tables which are stored at each station of the network. Routing information is broadcast or multicast according to three schedules; upon demand to show new routes, periodically to show recently changed routes, and less often to provide a complete dump of all known routes. A new route will trigger immediate re-broadcast so that this information is quickly disseminated. A new route is defined to be one with a better metric or a metric of infinity. A metric of infinity indicates a broken link; i.e., a particular destination is no longer reachable and thus all other destinations depending upon the newly unreachable destination are themselves unreachable. Periodically, routes are advertised. This advertisement serves primarily in most cases to notify all neighbors that everything they have stored is still correct regarding the broadcasting Mobile Host. On rarer occasions when the routing topology changes, the demand nature of the incremental update displaces the periodic transmission until an update interval transpires. In order to damp out oscillations, data is kept about how often the routes change. Based on this data, a decision may be made to delay advertising routes which are about to change soon, thus damping oscillations of the route tables.</p> |
