Stages of FTTx Network deployment and critical considerations
Fiber to the “Anywhere” is popularly represented as a generic term FTTx. In earlier days, the primary use of the optical fiber was, to support backhaul requirement of various telecom services like – Macro Cell sites, Enterprise locations, Central offices for Fixed Broadband etc. The density of drop points on fiber networks used to be very small in earlier era, typically 2 to 3 drop points per kilometre. Also, the technology was point-to-point, where both ends were connected using active device, without any passive splitting. There was limited scale deployment of FTTP or FTTH in premium localities, which were served using Point-to-Multipoint technologies. However, the scope and complexities of fiber deployment has increased multi-fold because of recent development in the application world, which demands low latency, highly elastic bandwidth with an ability to support time-based demand, enterprise grade high availability even at homes, adequate fiber count to support Any-Haul (X-Haul) requirements of 5G, Cloud adoption etc.
Due to enhanced complexities associated with the densification and constantly increasing demand of fiber at new sites, it is critical to understand every stage of deployment in detail, before deciding to invest in fiber infrastructure.
The various stages in FTTx deployment have been depicted below:
1. Design: This is one of the most critical stage in the FTTx network creation journey. At this stage, the network rules, guidelines and constraints are decided. For example, split ratio to be followed in the design is a critical consideration in any FTTH network and whether it should be 16, 32 or 64, needs to be decided at design stage itself. Similarly, the serving area boundary to be connected from a central office, is decided at this stage only. This stage is very important for converting business requirements into actual network design. Sometimes, the design is iterative process, based on the consultation between business owner and network planner. In such cases, scenario-based planning needs to be done on a good Design Simulation Tool before arriving at a design rule. Such tools help in optimizing the Capital cost of building a network at large scale.
2. Field Survey: This stage is closely connected with the Design process. Design is an iterative process and normally initial design is created on desktop, without visiting the actual locations. The accuracy of initial design or desktop design is dependent on the quality of digital data available. However, the final design requires actual site visits to capture the ground information like – feasibility of placement of Cabinet along the road or pole, whether cable laying has to be done on left or right side of the road, fiber entry gate of a walled community with multiple entry gates, availability of fiber / cable / conduit / Cabinet space in case it has to be taken on lease from infrastructure owner (e.g. Openreach in UK). Also, information related to way-leave or Right of way (RoW) is also collected at this stage. All this information with geo-tagging, is sent back to the Network designer to further fine tune the design to near accurate level. Traditionally, survey was done manually and used to be very resource intensive and time consuming. However, new location-based survey automation app has made this entire process very agile and completely eliminates the need of back-office work, post completion of field survey. Using the Survey automation App, the productivity of surveyor and designer can be increased by 3X times, saving significant time and money.
3. Build: This is the most time and resource intensive stage. After design finalization, engineering design is handed over to build team. The FTTx build team typically consists of – OFC Execution crew, Element installation technicians, Splicers and Quality audit engineers. While these teams are equipped with different machines and tools to perform their tasks, one of the biggest challenges associated with the Build process is, Synchronization and Orchestration of numerous activities involved. Also, reconciliation of varying quantity of different materials is the second major challenge. Third major aspect is capturing the As-build drawing, with high level of accuracy. Traditionally, all these tasks used to be done manually. However, increasing scale has made it practically impossible to manage thousands of tasks performed concurrently at different location and stitch them together. All these challenges can be mitigated using an Integrated Network Build Management Platform. The core of such platform is Geospatial Database Management system. Multiple tools and Apps get integrated on this Platform to automate entire tasks listed above and facilitate a single view to the Program owner. This Platform also helps in automating most of the task performed manually on the ground and ensures proper work flow to enable efficient end to end build process.
4. Connect: In any FTTx deployment process, network level deployment task is performed to provide the reach to the end points like Premises, enterprises or Cell sites. A popular term to depict access to FTTH is Home Pass. It means that network reach has been provided to the nearest feasible point to the home. In case the network has been built to provide 100% home passes, it typically means that the last elements of the FTTx network have been placed within 50 meter range from the home. In case of a request for an activation, no network level activity will have to be performed and just few fiber connectorization work should lead to activation of FTTH service to an end customer. Similarly, for extending Connectivity to a mobile cell site, a joint chamber or tapping point may be located within less than 100-meter distance, from where a cell site can be connected on fiber backhaul. In nutshell, last element of the FTTx network e.g., FAT (Fiber Access Terminal), OTB (Optical Termination Box), FTB (Fiber Termination Box) etc should be located near the end point to enable easy and fast connectivity to end points.
5. Activate: In earlier sections, we have covered points related to fiber infrastructure of FTTx. However, ultimate objective of FTTx network is to provide services to the end users like fixed broadband, high speed wireless connectivity, Enterprise VPN etc. In the service activation, all support systems of the network like OSS, BSS, Asset Management System etc. play very critical role. While there are lot of such systems available from different vendors, very few of them have capabilities to provide end-to-end logically connected solution. For example, there are many organizations having advance OSS system for logical network management and control. However, such systems need to be integrated with Physical Asset Management system, keeping records of OF Cable routes, Fiber utilization, splicing details etc. If the two systems are not integrated and correlated, multiple touch points will be required in the entire activation and asset reconciliation process. Lack of having integration of various subsystems hampers implementation of auto provisioning or Zero Touch provisioning for activation of the service.
The design, deployment and Management of a FTTx network is complex multi-stage process. There are a lot of inter-dependency among different stages of the network creation. Additionally, the process of network build and management has become highly complex due to increased scale. In such scenario, significant focus is needed on few critical aspects like – Very well-planned architecture for end-to-end service, heavy automation and minimum human intervention, strong linking of physical and logical assets etc.