When it comes to the cable selection between OS1 and OS2 single mode fiber, it’s essential to be clear that you are adopting these SMF cables for long-haul transmissions. Choose the proper cables based on your link length requirements.
OS1 optical fiber cables are applied for indoor network infrastructures, which are mainly deployed in internal building/campus networks, as well as internal cabling within telecommunication exchanges and data centers. Then OS1 cables are fit for your indoor application demands. OS2 optical fiber cables are more appropriate for outdoor and universal loose tube solutions, which would include external plant and most backhaul networks. When it is needed for outdoor network infrastructure, then OS2 is the way to go.