Syrian OEM Optical Line Terminals (OLTs) using NRZ modulation are deployed in national FTTP networks to convert electrical signals to fiber optic signals and manage PON traffic efficiently.

Overview of OLTs in Syria

An Optical Line Terminal (OLT) is the service provider endpoint of a Passive Optical Network (PON). It converts electrical signals from the provider's equipment into fiber optic signals for distribution to multiple endpoints, such as Optical Network Units (ONUs) or Optical Network Terminals (ONTs), and coordinates multiplexing across the network . OLTs can support various PON standards, including GPON, EPON, XG-PON, and WDM, with each port capable of serving multiple ONUs through split ratios typically ranging from 1:32 to 1:64, and up to 1:128 for XGS-PON .

NRZ Modulation in OLTs

NRZ (Non-Return-to-Zero) is a line coding method used in optical transmission where the signal does not return to zero between bits. NRZ is widely used in OLTs for efficient, high-speed data transmission over fiber, particularly in GPON and EPON networks. It is simpler and more cost-effective than alternatives like RZ (Return-to-Zero), making it suitable for large-scale deployments in Syria's FTTP infrastructure .

Syrian Deployment Context

Syria's BARQ NET FTTP initiative aims to deploy fiber-to-the-premises across all 14 governorates, including Damascus, Aleppo, Homs, and Latakia . Local companies such as OSC provide OEM and integration services, including supply, installation, and operation of OLTs, GPON ports, and optical cables for universities, ISPs, and public infrastructure . These OLTs are typically installed at central offices or distribution points and connect to ONUs at customer premises, supporting broadband, leased lines, and enterprise networks.

Key Features of Syrian OEM OLTs

• Line coding: NRZ for efficient optical transmission
• PON support: GPON, EPON, XG-PON depending on deployment
• Port capacity: Each port can serve 32–128 ONUs depending on split ratio
• Deployment: Central offices, university campuses, and ISP distribution points
• Local integration: Provided by Syrian OEMs like OSC, including installation, fusion splicing, and network management

Applications

Syrian OEM OLTs with NRZ modulation are used for:

• FTTH/FTTB broadband services for residential and commercial users
• Enterprise leased lines and high-speed connectivity
• University and government networks linking multiple campuses via optical fiber
• Wholesale access for ISPs under the VULA model in BARQ NET FTTP These OLTs form the backbone of Syria's passive optical network, enabling high-speed, scalable, and cost-effective fiber connectivity across urban and regional areas.