An optical network unit (ONU) is a device that transforms incoming optical signals into electronics at a customer's premises in order to provide telecommunications services over an optical fibre network.

1. Optical Network Unit
By Mohammed Azam
Emirates Telecommunication Corporation

2. ONU Introduction
An optical network unit (ONU) is a device that
transforms incoming optical signals into electronics at
a customer's premises in order to
provide telecommunications services over an optical
fibre network.
In Edition to ..
An ONU is a generic term denoting a device that terminates any one of the
endpoints of a fibre to the premises network, implements a passive optical
network (PON) protocol, and adapts PON PDUs to subscriber service
interfaces. In some contexts, an ONU implies a multiple subscriber device. An
optical network terminal (ONT) is a special case of an ONU that serves a single
subscriber.

3. Optical Network Terminal (ONT)
The ONT receives the signal from the OLT and converts into
usable electronic signals for the user‘s telephone, computer,
TV or other devices.
The ONT also serves to communicate IP traffic back to the
OLT, such that voice conversations can occur, Web pages can
be requested, and TV channels can be changed.
ONT can be connected to a battery backup device, providing a
limited time period (typically 8 hours standby) of lifeline
services.

4. ONT Types, Interfaces and
Services Supported
Huawei
Zhone
Alcatel
These are Main Vendors of ONT
used in Etisalat Network in UAE

5. Huawei

6. Huawei cont..

7. Zhone

8. Zhone cont..

9. Alcatel

10. ONU is the End Point of FTTH
network

11. Do you know this?

12. ONT
installation

13. Selecting ONT Location
Brown Building
When selecting for ONT location in Brown building, it should be in a place
accessible enough during service provisioning and maintenance. And in addition
to this, the following should be taken into account when deciding for the final
ONT location.
 Power socket availability
 Existing UTP cables, if any
 Internal conduit space
 Adequate cable route
Moreover, the locations listed below are to be avoided when installing the ONT.
 Below the windows. In close proximity to water seepage, water splash areas, etc.
 Behind heavy furniture.
 Inaccessible and unfavourable areas for example above false ceiling, kitchen, etc.
 Where the ONT will suffer continuous exposure to direct sunlight.

14. Selecting ONT Location Cont..
Green Building
 In Green building, location of the ONT cabinet shall be by developer‘s
responsibility and must be installed as per the following conditions.
 he cabinet should be at a common point where all internal conduits meet.
 The cabinet should be in central and accessible locations and shall house the following.
 - RJ45 patch panel/IDC modules
 - Micro ODF for fiber termination
 - Power sockets
 Should have sufficient space around the cabinet to allow access to installation and
maintenance.
 The cabinet should be installed at a height of 1200mm above finished floor level for
better working position and to prevent accidental access by children.
 Should be located where the farthest telecom socket must not exceed 90 meters from the
cabinet.
 Should not be installed adjacent to any electrical distribution.
 Should not be installed in the kitchen or near to washroom, and other wet areas.
 Should be located in air conditioned environment.

15. ONT Cabinet for Residential
Building / Villa
 Minimum Height: 600mm
 Minimum Width: 425mm
 Minimum Depth: 120mm
 Lockable door
 Should be fitted with RJ45 patch panel
 Should be fitted with micro ODF
 Should have two power sockets for
ONU and battery rectifier powering
 Should have adequate number of
aesthetically designed holes on the front
door for ventilation
 Should be installed flush mounted on
wall

16. ONT Cabinet for Commercial
Building
 Minimum Height: 600mm
 Minimum Width: 600mm
 Minimum Depth: 300mm
 Suitable for 19‖ rack equipment
mount
 Lockable door
 Should be fitted with RJ45 patch
panel
 Should have two power sockets for
ONU and battery rectifier
powering
 With provision for air circulation
 Partially concealed or Wall mount
installation

17. ONT Installation
Normal Customer Place
 The ONT and its associated accessories shall be installed at the
location as identified during pre-installation survey. The fiber
into the ONT shall be managed using either of the following
methods depending on the site conditions.
 Using an Extended Micro-ODF.
 Using PVC trucking and Micro-ODF / Rosette.
ONT Installation with Extended Micro-ODF As shown above is
Huawei OT 550 ONT set-up using the extended micro ODF

18.  Remove the knock-outs on the top to align the Extended Micro-ODF
with the output ports of the ONT. All the knock-outs have to be
removed for a Huawei OT550 all the knock-outs except the ones at the
farthest end have to be removed for a Zhone NID -2520.
Details for installing the extended micro
ODF are detailed below.
Cont..

19. Cont..
 Install the SC/APC adapter in the holder. The
connector guiding slots of the adapter should face up.
 Wall mounts the Extended Micro-ODF. Use the slits
at the back of the unit to insert the screws.
 Guide the incoming fiber and the patch cord to the
ONT is shown below.

20. ONT Installation with PVC Trucking

21. When using the square Micro-ODF, the Micro-ODF will be mounted adjacent to
the telephone socket outlet (3/4A or 4/4A). It can be mounted to the right or left
of right of the telephone socket depending on site conditions connecting Service
Outlets.

22. ONT Deployment and Installation Rules
 ONT Cabinet for Commercial building/villa (green)
 ONT shall be installed in a Common Area where power is available or can be extended towards
ONT location and which can be accessed anytime during service provisioning and
maintenance works.
 ONT shall be installed where the farthest room it will serve is less than 90 meters.
 ONT shall be installed where UTP cables meet, if existing. However if UTP cables end up in an
inaccessible room, ONT shall be installed in a common area disregarding the existing UTP cables.
 ONT shall be enclosed in a lockable cabinet for protection and security (especially in locations where
ONT is within child‘s reach, like hallway, etc.)
 New ONT shall be installed if the existing services exceed the available ports on the ONT and if UTP
cabling requirements exceed 90 meters total length in a single run.
 New ONT shall be installed if the first ONT becomes inaccessible due to room partitioning or where
flat/villa previously occupied by single family converted to shared-accommodations.
 In a villa occupied by one-family per floor, ONT shall be installed in each floor and shall not be
shared with others. However, if one of the floors is shared by multiple families or tenants, ONT shall
be installed in a common area and shall be shared by the occupants in this floor.
 New ONT shall not be installed for a different customer sharing the same apartment if free
ports are available in the first ONT and its location is accessible (installed in a common area).
Shared ONT Typically ONT‘s are usually dedicated to an individual
single user account, i.e. flat / villa owner. However, if ONT is shared by
multiple users account, the following guide shall be taken into
consideration when deploying ONT in shared accommodations.

23. ONT Deployment and Installation Rules cont..
 Shared ONT Installation
 The ONT may also be alternatively wall mounted in a
closed telephone room outside an apartment.
 It is to be ensured that adequate cable routes are
available to lay more than one CAT6 cable from the
telephone room to the apartment.
 The ONT location should be one which is always
accessible and has an electric power socket provisioned.
Shared ONT Service Provisioning Scenarios
 Service connection in apartment with ONT in common
area. Customer can be connected by pulling a separate
UTP cable from the ONT location up to the room.

24. Over view of Presentation
 ONU Introduction
 Optical Network Terminal (ONT)
 ONT Types
 FTTH network
 ONT installation
 ONT Deployment and Installation Rules

25. Thank you