  Satellite edge computing has become a promising way to provide computing
services for Internet of Things (IoT) devices in remote areas, which are out of
the coverage of terrestrial networks, nevertheless, it is not suitable for
large-scale IoT devices due to the resource limitation of satellites. Cloud
computing can provide sufficient available resources for IoT devices but it
does not meet the service requirements of delay sensitive users as high network
latency. Collaborative edge and cloud computing is to facilitate flexible
service provisioning for numerous IoT devices by incorporating the advantages
of edge and cloud computing. In this paper, we investigate the virtual network
function (VNF) placement problem in collaborative satellite edge and cloud
computing to minimize the satellite network bandwidth usage and the service
end-to-end delay. We formulate the VNF placement problem as an integer
non-linear programming problem and propose a distributed VNF placement (D-VNFP)
algorithm to address it, as the VNF placement problem is NP-hard. The
experiments are conducted to evaluate the effectiveness of the proposed D-VNFP
algorithm. The results show that the proposed D-VNFP algorithm outperforms the
existing baseline algorithms of Greedy and Viterbi for solving the VNF
placement problem in satellite edge and cloud computing.
