Abstract: In delay/disruptiontolerant network (DTN) such as city bus network， all or part of the topological information can be used for routing calculation. A topologybased double slot routing (DSR) algorithm for the DTN is proposed. The DSR algorithm divides the DTN cycle into time slots. The best path is selected from valid paths in the current and next slots. It can thus ensure that most traffic transmission are completed before link interruption and offer tolerance to predictable link interruption. In path choosing， the DSR algorithm uses transmission delay and delay jitter rate as path parameters to ensure transmission reliability and stability. It also exploits alternate paths to provide tolerance for unpredictable link interruption. Simulation and performance analysis are performed， and the results show that the asproposed algorithm is linkinterruptiontolerant with higher message delivery ratio and lower average transmission delay.

Key words: delay/disruptiontolerant network, routing, topology information, double slot, delay, delay jitter