Issue link: https://www.e-digitaleditions.com/i/1327492
20 I ICT TODAY The 10G passive optical LANs (POLs) have emerged as a viable alternative, providing strong life cycle perfor- mance and requiring only the end points to change when it is time to upgrade—with the optical fiber infrastructure remaining intact. Enterprises faced with increased demand for internet of things (IoT), cloud services, big data, wireless connectivity and more, with secure and stable performance, now have the option to adopt a straight- forward and scalable solution using optical fiber cable to support Ethernet connectivity to the enterprise. THE EVOLUTION TO PASSIVE OPTICAL LANS To fully appreciate the potential in deploying 10G POLs, it is important to look at the evolution of Fiber-To-The- Home (FTTH) networks, often referred to as Fiber-to-the X (FTTx) to connote Fiber-to-the Building (FTTB) and so on. The FTTx passive optical network (PON) began with BPON, which for several years was used for lower bit rates of one Gigabit (G) and slower. The technology gradually evolved to GPON, a low-cost, well-proven tech- nology supporting higher bit rates up to 2.5G. More recently, it has evolved to higher speed versions such as XGS-PON (10G) or NGPON2 based on wave division multiplexing (WDM) up to 40G. Since GPON is a cost-effective, tried-and-tested technology that has been proven to deliver more band- width to consumers, it is now being used for emerging enterprise LANs. Systems integrators, such as a BICSI Registered Communications Distribution Designer (RCDD), are taking their FTTx solutions and moving them into enterprise network applications with the addition of the extra LAN requirements, including power over Ethernet (PoE), advanced network security, and redundancy. Also called fiber-to-the-desktop, this GPON-based technology creates a cost-effective LAN with a multitude of capabilities to support more bandwidth and services, as well as to future-proof enterprise networks. THE FIBER ARCHITECTURE BEING ADOPTED BY ENTERPRISES Based on the standardized and widely deployed passive optical network (PON) architecture, POLs have been deployed in enterprise networks for several years. Key software features and design adaptations have con- tributed to making POL a good fit for the enterprise market. The POL relies on a passive point-to-multipoint architecture that includes in-building cabling with optical singlemode fiber (SMF) using GPON technology and optical splitters. The SMF provides connectivity right to the desktop, replacing the traditional and bandwidth- limited Cat 5 or Cat 6 cables. This eliminates the need for complex and expensive active Ethernet switches and provides benefits to the network operator including: • Capex saving for cables and equipment • Opex saving from lower energy and cooling requirements (green technology) • Space saving with fewer racks of equipment and no remote hubs • Secure and reliable communications over optical fiber cables. The optical line terminal (OLT) is the active central aggregation point connected to the WAN/feeder cable from the service provider for high-speed internet and corporate servers. Typically located in the main data center, the OLT acts as the brains of the network, con- trolling the fiber's light signals to end-user devices. Optical network terminals (ONTs) are end devices that are located close to the user. They can be mounted inside telecom room (TR) closets or deployed in the work group area. The ONTs converge disparate services including data, voice and video over one SMF that feeds into local wireless access points (WAPs) or routers. These devices then enable local wired connectivity to the network, as well as Wi-Fi and RJ45 connectivity with PoE to connected devices. Since GPON is a cost-effective, tried-and-tested technology that has been proven to deliver more bandwidth to consumers, it is now being used for emerging enterprise LANs.