Fiori Back-End Requirement

Our ERP Solution is SAP ERP 6.0 EHP 5.0 SP 6.0 / NetWeaver 7.0 EHP 2.0 SP 9.0

We wish to implement Fiori apps, but I am confused with what I am reading online as Back-End NetWeaver Requirements.

If you see this link :

http://help.sap.com/fiori_bs2013/helpdata/en/ec/a91e530fe4e60be10000000a441470/content.htm?frameset=/en/5f/fc1f533f86ef28e10000000a4450e5/frameset.htm&current_toc=/en/40/1b675374bc6655e10000000a423f68/plain.htm&node_id=6&show_children=false

It seems to say that you bust be on NetWeaver 7.4 on the Back-End.  Is that true?

I was under the assumption that if you have a Hub Gateway configuration you can use older NetWeaver versions for the Fiori solution.

Thanks for your help in advance