- FTTH networks use fiber optic cables to directly connect homes and businesses to a central access point, enabling high-speed broadband access. Service providers in Saudi Arabia are heavily investing in FTTH to meet customer demands.
- The paper discusses GPON, the predominant FTTH architecture using a point-to-multipoint topology with passive optical splitters. Distributed splitting is commonly used for flexibility.
- Key components of FTTH infrastructure include the feeder network connecting POPs to distribution points, the distribution network, and last mile access network connecting to customer buildings.
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