Alternative communication protocol between SAP Sourcing and PI 7.31 AEX

Dear Experts

We are integrating SAP Sourcing 9.0 and ECC 6.0 EHP6 thru a SAP PI 7.31 AEX system. We know that the supported communication protocol between SAP Sourcing and PI system is FTP(s) or Shared Folder. We would like to know if there is any other alternative for communication protocol. e.i. HTTP connections or any other option. Please advice.

Thanks

Kind regards

Emanuel