Virtual Baseband Unit Splitting Exploiting Small Satellite Platforms

Recently, border monitoring and security has become an important topic since current methods against illegal immigration are expensive and inefficient. In particular, inefficiency and ineffectiveness increase when monitoring operations are focused on complex borders, where there is no available/reliable connectivity. In the last decade, the deployment of different kinds of unmanned aerial vehicles was seen as the main paradigm to provide on-demand wireless network access. Significant research work has been done on so called mobile base stations. Nevertheless, drones have specific technical limitations in terms, for example, of battery life and carried weight. Given above fundamental limits, network virtualization becomes a fundamental paradigm for system realization. In the last years, baseband processing was not seen any more as a monolithic block but has been studied as a chain of virtual functions. Especially, baseband unit can be split into five sub-blocks belonging to layer 1 to layer 3, where each degree of splitting implies more and more stringent requirements to be guaranteed, mainly in terms of throughput and latency. Split E is the logic separation of hybrid automatic repeat request from lower layers, which imposes the most flexible requirements. On the other hand, Split D (forward error correction, encoding/decoding logic functions) sets more stringent bounds on throughput and latency so that it requires careful study and detailed analysis for a correct system-level design. The main objective of this article is to study theoretically and numerically (i.e. via simulations) Split D to make it feasible with the help of small satellites. The paper will study the structure and the capabilities of small satellites to be used as small data centers to host radio access virtual network functions like forward error correction. The theoretical analysis is supported by simulations in order to highlight advantages and challenges of the proposed approach.