Information-Centric Wireless Sensor SAGIN With Decentralized Caching Status Aware Multiple Subsystem Nested Coded Caching

Information-centric networking (ICN) can efficiently utilize bandwidth resources and reduce network data transmission latency, but coded multicast gains are not considered. A novel multiple-subsystem nested coding caching (MSNCC) is then proposed in hierarchical multirelay wireless sensor space-air-ground integrated network (SAGIN) with distinct sensor cache capacities and coded caching for potential coded caching gains. The group-based and zero-bit padding coded caching schemes are tightly coupled with two divided subsystems: 1) network layer placement and 2) physical-layer delivery. Through decentralized caching status (DCSs) aware coded caching optimization, the first subsystem achieves caching gains between adjacent layers, and the second subsystem directly exploits coded multicast gains between a server and several sensors. In situation I of the number of sensors larger than that of files, the MSNCC adopts the group-based decentralized caching to transmit coded subfiles between relays and sensors. In situation II of the remaining scenarios, the zero-bit padding coded caching improves link rate and system complexity. The innovation is the MSNCC with distinct sensor cache capacities by combining group-based decentralized, zero-bit padding, and hierarchical caching together. It effectively improves the link load in the worst circumstance by exploiting potential coded multicast opportunities among relays for different transmissions. Simulation results indicate that, in situation I, the MSNCC obtains approximately 38.5% and 26.5% reduction in delivery rate compared with those of uncoded caching and zero-bit padding coded caching, respectively. It also achieves about 33.3% rate gains compared with that of the uncoded caching.