In-network guidance activated with overhearing for mobile wireless multi-hop networks

In-network guidance for off-path caching, called Breadcrumbs, has been proposed for cache networks. In Breadcrumbs, during content download, a router holds a pointer, breadcrumb, which denotes the latest download direction. When a content request occasionally encounters a breadcrumb along its default-path to the repository, location-based routing is switched to hop-by-hop breadcrumb-based routing and it is forwarded to offpath cache. In our previous work, we evaluated Breadcrumbs in fixed wireless multi-hop networks and showed that total network throughput is significantly improved. In this paper, we focus on mobile wireless multi-hop networks where Breadcrumbs trail might be fragmented due to node mobility. To resolve this technical problem in mobile environment, we propose a new in-network guidance method, overhearing-aided Breadcrumbs. In overhearingaided Breadcrumbs, a router which overhears content download by other nodes makes one-hop breadcrumb. Our evaluation results show that proposed overhearing-aided Breadcrumbs outperforms conventional Breadcrumbs in mobile wireless multi-hop networks.