An optimization model for fragmentation-based routing in delay tolerant networks

Abstract

The explosive growth of mobile data traffic has raised big penetration to cellular network. Fortunately, offloading part of traffic through Delay Tolerant Network (DTN) would be a promising option to relieve load pressure. However, the existing routing strategies designed for DTNs are inappropriate in offloading scenario, where i) large data item would take on the dominance of mobile traffic, ii) centralized control can be exploited with merge between DTN and cellular network. To improve the routing performance of large data transmission, we propose a novel optimization model by creating two-tier solution space based on fragmentation, maximizing the probability that the requested data item is successfully delivered before expiration, taking limited buffer space as constraint metric. Moreover, a specific routing scheme is instantiated from our model, which is supported by uniform fragmentation and fine-grained path selection. Extensive trace-driven simulations show that our scheme is more appropriate for offloading case with outstanding performance in terms of replication overhead and acceptable routing capability.

创新点

通过容断容迟网络分流数据,已成为缓解蜂窝系统流量负载的前瞻性举措。然而,针对容断容迟网络的路由策略不适用于具有以下特征的分流场景:1)大容量文件在移动流量中的占比较高;2)蜂窝网络引入了集中化控制的优势。因此,本文创新性地以节点缓存空间的有限性为约束条件,以最大化数据成功递交率为优化目标,基于分片传输策略,提出了具有双层解空间的优化模型。此外,利用均匀分片策略及细粒度的路径选择机制,实现了基于上述优化模型的路由策略,在大幅度降低网络副本开销的情况下保证了路由传输性能。