Funding for this research was provided by:
Research on Joint algorithm of Network selection and Cognitive Spectrum allocation in High-Speed Rail Communication Environmen (61661026)
Received: 20 November 2019
Accepted: 30 January 2020
First Online: 12 March 2020
Ethics approval and consent to participate
: This article does not contain any studies with human participants or animals performed by any of the authors.All authors agree to submit this version and claim that no part of this manuscript has been published or submitted elsewhere.
: The authors declare that they have no competing interests.