GPON Traffic Flow in Network

by pk-admin Gpon

IP Network (Ethernet Frame)==OLT (GEM Frame)==ONT(Ethernet Frame)

OLT Broadcast All Data (GEM1,GEM2…) to ONTs,but in ONT it will filter using Port ID in GEM Frame , Once ONT Receive GEM Frame will process only data which belongs to it. OLT Assigning different time slot to each ONT.and ONT can only send back data on that specific time slot assigned by OLT.

Data Transmission ;Downstream:

Downstream :From OLT to ONT (User)

Max 2.5 Gbit/s Wave length Downstream: 1480 nm-1450 nm , 1490 ;data packet transmitted in an broadcast manner (AES encryption used to prevent eavesdropping)

Data Transmission ;Upstream:

Upstream :From ONT (User)  to OLT

Max 1.25 Gbit/s  ,Wave length Upstream: 1290 nm – 1330 nm (narrowed) , 1310 nm;

ONTs are located at different distance ,(same wavelength + Same fiber ) so data packet transmitted in a TDMA manner .

1.Distance OLT-ONT measured.

2.Timeslot allocated according to distance.

3.ONT send upstream according to granted timeslot.