Towards an end-to-end delay analysis of LEO satellite networks for seamless ubiquitous access

LEO satellite networks, with moderate propagation delay and low terminal power requirement, are considered as a promising solution to providing global seamless access services for ubiquitous computing. In order to satisfy the requirement of accessing computing resource for users, end-to-end delays should be bounded for a continual and reliable connectivity. But given dynamic topology and non-uniform distribution of terrestrial users, end-to-end delays within LEO satellite networks are liable to fluctuate. Hence, to examine the delay constraint, an analytical model based on a tandem queue is established under a hot-spot traffic pattern, which is unfavorable for bounded delays. The departure interval moments of a target flow are calculated and fitted for the next link as input parameters, from which queuing delays under cross flows are iteratively obtained. The analytical results show that this model is able to depict the influence by the traffic pattern with satisfying accuracy, which is valuable for the design of routing schemes in satellite networks.