Multiple Links on AP-Sms

We need to ensure that on a Service Provider’s Tower Spectrum is utilized well.So we are planning to put Advantage AP-SM setup.

Since the Service Provider has G-703 interface for Connectivity as Base Station, we are using G-703 to Ethernet Convertor for Connectivity.How do I have multiple Links being fed to Advantage AP & then on SM separate out all links , making sure in the end that each link is a point to point link .Shall we need L3 devices at base Stations & at SM both end , or only at SM end only.