SpringerOpen is just a brand of the company Springer Nature. You can find some info here. It's also the name of the website where you can access the articles. It allows them to cram the word "Springer" in more places if they brand every single one of their open access journals. It's like how McDonald's chicken nuggets aren't just nuggets, they're mcnuggets. Springer's open access journals aren't just open access, they're "SpringerOpen".
Citations of journal articles do not typically include the publisher. The journal's name is sufficient. In fact, if you go to to your journal's website, they explicitly say:
Citing articles in EURASIP Journal on Wireless Communications and Networking
[...] Article citations follow this format:
Authors: Title. EURASIP J Wirel Commun Netw [year], [volume number]:[article number].
Since journals can (and do) change publishers, there is no point in listing the publisher. In fact, this could be actively harmful if the journal changes hand at some point in the future. People will wonder if they're looking at the correct thing.
If you look, you will also see that the copyright holder is "BioMed Central Ltd", which is owned by Springer Nature. So if you are really intent on listing something, I would list that. The company's HQ is in London.