FTTx Solution - White Paper
- 1. White Paper By: Syed Firas Uddin September, 2015 FTTH Network Solution
- 2. White Paper: FTTH Network Solution 1 Introduction: Broadband services have been an intense topic of conversation and debate for a number of years across the globe. There is a great demand for high speed broadband access network by users for triple play services as the data communication between users is at its highest levels. In order to meet the present and future high speed broadband requirement, Fiber to the Home (FTTH) solution is the ideal technological solution for it. FTTH is one of the most important technologies in the next generation network. It increases the access layer bandwidth and builds a sustainable development access layer network. Not only do fixed access networks benefit from FTTH solutions, but advanced wireless networks do as well especially in regard to increased backhaul capacity. Service providers across the globe are investing heavily on the FTTH solution to meet the high speed customer demands. As it involves heavy investments the different FTTH solution parameters of architecture, access design, implementation and product selection should be carefully thought of. An FTTH network is a long-term investment and the anticipated lifetime of the cable in the ground is at least 20 years. With the active equipment likely to be upgraded several times in this timeframe, it should be possible to reuse the infrastructure. So decisions made at the start of an FTTH project will have long term consequences. In order to build this new generation of optical access network, this solution draws on the technologies of the Gigabit Passive Optical Network (GPON), enabling service providers to deliver services in a simple and straightforward manner, providing cost-effective high bandwidth and multi-service support capabilities. This allows service providers to become more competitive and adapt services to ever changing customer demands. This white paper provides an overview on the FTTH network in terms of architecture, topology and infrastructure from a service providers perspective to meet the ever growing high speed broadband demands of customers. FTTH Network Solution: Fiber to the home (FTTH) network consists of an optical fiber based access network, connecting a large number of end users by a dedicated fiber to a port on the equipment in a central point known as an access node or point of presence (POP). Each POP contains the necessary electronic transmission (active) equipment to provide the applications and services, using optical fiber to the subscriber. Each POP, within an area, is connected to a larger metro fiber network all of which is based on the GPON technology. FTTH Topology: As the FTTH network comprises of active and passive elements, it is important to make a clear distinction between the topologies used for the deployment of the fiber over the passive elements and the transport of data over the fibers on the active elements. The two main topologies are Point to Multipoint and Point to Point topologies.
- 3. White Paper: FTTH Network Solution 2 In Point to Multipoint (P2MP) topology a single feeder fiber is provided from the POP to a branching point and from there one individual, dedicated fiber is deployed to the subscriber. A passive optical network technology such as GPON uses passive optical splitters at the branching point. FTTH topologies In a Point to Point (P2P) topology dedicated fibers are provided between the POP and the subscriber. Each subscriber has a direct connection with a dedicated fiber. The route from the POP site to the customer will probably consist of several sections of fibers joined with splices or connectors, but provides a continuous optical path from the POP to the subscriber home. Architecture: The FTTH network realizes the GPON architecture using the P2MP topology. In the GPON technology the dedicated one fiber per user utilizes in downstream direction a wavelength of 1550nm and in upstream direction a wavelength of 1310nm. GPON Architecture GPON realizes P2MP transmission through the passive optical splitter. The fiber connected to the OLT port is split through by the splitter into multiple channels to the ONUs of different users. The
- 4. White Paper: FTTH Network Solution 3 distance between OLT and ONU is around 20km. With the GPON technology, the Optical Distribution Network (ODN) does not have active nodes. The feature of passiveness makes the network deployment flexible, because the equipment room and power supply are not needed. Almost all of the service providers across the globe including Saudi Arabia are opting for P2MP GPON technology based FTTH architecture due to reduced cost (the equipment and fiber at the CO are shared by users, so the cost is lower than of P2P) and easy maintenance (the active equipment is removed from the access network, so the effect from electromagnetic interference, thunder and lightning is reduced where failure rate of the line and the external equipment is reduced). Further in GPON technology the passive optical splitter can be placed in two types as either in centralized splitter architecture or cascaded/distributed splitter architecture. In Saudi Arabia all the service providers use the 1:32 passive optical splitting ratio in their FTTH network. Passive Optical Splitting Scenarios A centralized approach typically uses a 1x32 splitter located in a fiber distribution hub (FDH). The hub may be located anywhere in the network. The splitter is directly connected via a single fiber to a GPON optical line terminal (OLT) in the central office/POP. On the other side of the splitter, 32 fibers are routed through distribution panels, splice ports and/or access point connectors to 32 customer homes, where it is connected to an optical network terminal (ONT). Thus, the GPON network connects one OLT port to 32 ONTs. A cascaded approach may use a 1x4 splitter residing in an outside plant enclosure. This is directly connected to an OLT port in the central office. Each of the four fibers leaving this stage 1 splitter is routed to an access terminal that houses a 1x8 stage 2 splitter. In this scenario, there would
- 5. White Paper: FTTH Network Solution 4 be a total of 32 fibers (4x8) reaching 32 homes. It is possible to have more than two splitting stages in a cascaded system, and the split ratio may vary (1x32 = 2x16, 1x32 = 4x8, 1x32 = 8x4). All the service providers in Saudi Arabia are utilizing the distributed passive optical splitting GPON architecture as it provides reduced splitter cabinet requirements and flexibility in split ratios in serving area reaching out to more customers. Infrastructure: The FTTH network infrastructure comprises of active elements and passive elements. Major service providers in Saudi Arabia deploy FTTH network infrastructure as below: Typical FTTH network As shown above the FTTH network infrastructure is segregated into various levels and sub networks for better operations. - Feeder Network: This includes POP to FDT connectivity where an optical fiber cable (usually a G.652D ducted / micro fiber cables placed inside ducts/micro ducts) from POP ODF is fed to the feeder ODF in the FDT where also the distribution splitters are housed of the serving area. - Distribution Network: This is the FDT to FAT (Fiber Access Terminal / Closure) network work which contains all the distribution cables under an FDT- (usually a G.652D ducted / micro fiber cables placed inside ducts/micro ducts).
- 6. White Paper: FTTH Network Solution 5 - Access Network: This is the last mile connectivity from FAT to Customer Building (usually an ODB), which further runs into the customer building to CPE through Face Plate (usually a G.657A indoor fiber cable). The transmission medium is the fiber cables (ducted/micro/ribbon) of various high counts. The Active infrastructures which require power are the OLT (placed in central office/POP) and ONT/CPE (placed in customer building). The Passive infrastructure that do not require power are the FPP & ODF (placed in central office/POP), feeder and customer ODF (placed in FDT), FAT (placed in a manhole) and an ODB (usually placed on customer building walls). The physical environment of the FTTH network infrastructure based on density and building type can be split into: - Single Dwelling Unit (SDU): Single Dwelling Unit is for a Single Independent Customer. This can be residential or commercial end user. Residential building types are Villas and commercial is usually stand alone office building like Banks, Coorporate offices etc. Here inside an ODB a low ratio splitter is used (usually 1:4) as the number of end users are less. Single Dwelling Unit (SDU) Multi Dwelling Unit (MDU) - Multi Dwelling Unit (MDU): MDU is multi-tenancy Business Areas or Multiple residential Apartment. An MDU can be either all commercial, all residential and or combination of both where more number of customers are concentrated. Here inside an ODB a high ratio splitter is used (usually 1:16 or 2:32) as the number of end users are more. The main influences on the method of infrastructure are type of FTTH site, size of the FTTH network, initial cost of the infrastructure deployment (CAPEX), running costs for the network operation and maintenance (OPEX) and network architecture (GPON).
- 7. White Paper: FTTH Network Solution 6 A proper FTTH network infrastructure shall be fully capable of providing a provision of high bandwidth services and content to each subscriber, a flexible network architecture design with capacity to meet future needs, a fiber connection of each end subscriber with maximum available capacity for future service demands, support for future network upgrades and expansion, minimal disruption during network deployment, to promote fiber networks gain acceptance by service providers and to provide benefit to FTTH end users. Market Outlook: Saudi Arabia’s ICT market is the biggest in the Middle East in terms of capital value and volume of spending. The future is promising, with both government and businesses keen on keeping up to date with the latest telecom developments. Smart technologies, in particular, offer interesting opportunities for investors. Services are provided by five Fixed Network Operators namely – STC, Mobily, ITC, Bayanat and Go Telecom. With a population of around 27 million and approximately 46 million registered households, the fixed broadband market is experiencing a major technology shift from ADSL to FTTH, with STC and Mobily heavily expanding FTTH coverage across Saudi Arabia, and another companies – Go Telecom and ITC also offering FTTH services. This makes an interesting opportunity for vendors, contractors and suppliers to tap into this market. Conclusion: Several fiber architectures have been developed to support FTTH deployments. While distributed splitter based architectures are suitable for the for the service providers in Saudi Arabian environments with dense concentration of customers (either SDU or MDU) offering reduced infrastructure foot print, reduced fiber counts and flexibility for gigabit highspeed bandwidth demands which all in turn can dramatically reduce up front network costs. Optical Fiber network solution as an access technology is essential for service providers as not only it meets the broadband needs of customers but also forms a major part of the cellular backbone where 90% of cellular calls are carried atleast partially over fiber. New technologies like the Internet of Things (IoT) can be fed with required highspeed broadband connections with FTTH network solution for households which will further inspire new products and services and could open entire new sectors in the business world