FTTx Architecture - Central Office and Splitters

Transcription

1 FTTx Architecture - Central Office and Splitters

2 The PON Network - Basic Network Architecture Schematic Diagram PON Network 1550 nm DS Overlay 1310 nm US Digital 1490 nm DS Digital KEY: OLT OPTICAL LINE TERMINATION ONT OPTICAL NETWORK TERMINATION ODN OPTICAL DISTRIBUTION NETWORK AT ACCESS TERMINAL FDH/FDT FIBER DISTRIBUTION HUB/TERMINAL VAM VALUE ADDED MODULE Headend Access Customer 2

3 Attraction of PON FTTP No active components. From the Central Office to the end user an FTTP network is typically passive Dramatically reduces network maintenance and cost Fiber is non-conductive, Fiber can carry a large amount of traffic, and Fiber has a long shelf life. Single fiber to end user Capable of providing revenue-generating services such as voice, high-speed data, analog or digital CATV, and video on demand (VOD) Local battery back-up and low power consumption Reliable, scalable, secure Future proof architecture 3

4 Generic Layout 4

5 PON Single Fiber Architecture Models Four Primary PON Designs 1. Distributed Splitting 2. Centralized Splitting 3. Splitting in the CO 4. Point to Point Central Office / Head-End Central Office / Ethernet/EFM Head-End Broadband (BPON) GigaBit (GPON) Ethernet (GEPON) P O N 5

6 Typical PON Architectures OLT ODN ONT P2P Ethernet In-The-First Mile P2P Splitting In the CO/HE Optical Line Termination Single Coupler FDH - Cross Connect 1x32 Coupler FDH - Fiber Service Area Interface Centralized Splitting Optical Line Termination Single Coupler 1x32 Coupler Access Terminal Distributed Splitting Optical Line Termination Distributed Couplers 1x8 Coupler 1x4 Coupler 6

7 Distributed Splitting 7

8 Distributed Splitting 8

9 OSP Implications for FTTP Deployment Splitter Deployment Strategy Distributed/Cascade Central Office Fiber Distribution Hub Fiber Access Terminal Optical Line Termination 1 x 4 Splitter 1 x 8 Splitter. 1 x 8 Splitter. Concept : Splitters are located in FDH and at OSP locations Theory : Cascading splitters in OSP will minimize the amount of fiber that needs to be deployed to provide service. Reality : Cascaded splitters reduce distribution cable material costs but creates inefficient use of OLT PON Ports and may increase the testing and turn-up time of customers. 9

10 Distributed Splitting Model Advantages: Least Expensive Passive System to Design - Minimal up-front network CAPEX requirements - Uses Fiber-lean Feeder and Distribution System Can be efficient - Where Take Rate is High and Fairly Stable - Where Growth is Not an Issue Disadvantages: Limitations on Bandwidth and Adaptability - No Single Splitter Configuration or Adaptation Point - High splitting ratio may limit future network scalability and electronics Inefficient where Take Rate is Low (<50%) Complex to Grow/Scale 10

11 Centralized Splitting Model 11

12 Centralized Splitting Model 12

13 OSP Implications for FTTP Deployment Splitter Deployment Strategy Centralized Central Office Optical Line Termination Fiber Distribution Hub 1 x 32 Splitter Fiber Access Terminal Fiber Access Terminal Concept : All splitters are located in FDH OSP locations Theory : Centralizing the splitter locations for a neighborhood will maximize OLT utilization and provide a single point of access for troubleshooting. Reality : Provides best OLT utilization & flexibility in limited take rate builds, provides easy craft access for testing and turn-up but increases the distribution cable material costs. Allows for ease in transitioning to other PON technologies. 13

14 Centralized Splitting Model Advantages/ Disadvantages Advantages: LCP Consolidates Local Subscriber Configuration - Ability to service 32 or more (typ ) Subscribers per PON - Provides for a central turn-up location pointing to the OLT and ONT Balances network scalability with up-front CAPEX - Fiber-lean Feeder & Fiber-rich Distribution System - Provides dedicated Optical Path from FDH to Subscribers - Easily adaptable for future WDM PON and split ratio changes Supports Efficient Growth Strategies Disadvantages: Requires Truck-Roll to FDH for Splitter Connection/Mgt - May increase cost of incremental subscriber turn-up 14

15 P2P/CO Splitter - Homerun Model 15

16 P2P/CO Splitter Homerun Model 16

17 Central Office / Head End Connection Methods Central Office Equipment Frame Fiber Distribution Frame Line-up Cable Entrance Vault OSP Cable To FDT OLT Equipment Patchcord Equipment Termination Panel Cross Connect Patchcord OSP Termination Panel Factory Terminated Multi-fiber Intra Facility Cable Splice Panel OSP and OLT fibers are connected in Fiber Distribution frames Excellent test access and flexibility Excellent balance of cost and flexibility More floor space is required for FDF bays Cross connect is the best solution for FTTP deployments Most service providers use cross connect for their core fiber networks already 17

18 P2P/CO Splitter Home Run Advantages/ Disadvantages Advantages: Dedicated Optical Path (Provider-to-subscriber) - All Switching And/or Splitting at Central Point - Can be easily adapted from splitters to Point to Point Network - Only Splices/Connectors in Field Highest Bandwidth Capacity and Adaptability No Truck-Roll Subscriber Configuration Disadvantages: - Port-by-Port Turn-up of Subscribers from CO Up-Front CAPEX Investment Required - Uses Fiber-rich Feeder and Distribution System - High Fiber Counts in CO / Head End 18

19 Next Generation FDF Solutions - The Challenges Service providers are facing increasing pressure to: Reduce service turn-up time Reduce technician errors Reduce maintenance expenses Reduce labor costs Resolve customer problems faster Traditional FDF solutions do not address these issues well enough Critical question How do you make these connections in the most cost effective manner possible while maintaining flexibility and reliability in the network 19

20 Next Generation Fiber Distribution Frames What you should be looking for. Superior Access with no congestion Higher density LC connectors provide greater density over SC connectors On frame splicing without taking up termination capacity Craft friendly parts resulting in faster connections with fewer errors Integration of splitters and other optical components Promotes quick configuration changes in dynamic networks Please stop by the TE Booth for more information 20

21 Thank you. 21