Does a reduction in split ratio increase the bandwidth available?

• A. False
• B. True
• C. Not applicable
• D. Depends on wavelength

Answer: (B)

In a PON-style network, the total bandwidth coming from the OLT is shared among all subscribers behind a splitter. The split ratio determines how many subscribers share that same fiber path. When you reduce the split ratio, there are fewer users sharing the same capacity, so the bandwidth that can be allocated per user increases (up to the total capacity of the link). For example, with a fixed downstream capacity of 2.5 Gbps, moving from a 1:32 split to 1:8 raises the per-user share from about 78 Mbps to about 312 Mbps, assuming equal sharing and no overhead. The same idea applies upstream with the scheduler. So, yes, lowering the split ratio increases the bandwidth available to each user (the total link capacity doesn’t magically rise, it’s just divided among fewer users).