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OSP PLANNING AND DESIGN PROCEDURE: It is specialized processes leading to a successful installation and operation of a fiber optic network. OSP Planning and Design in fact includes determining the type of communication system in the telecom network, which will be carried over the network, the geographic layout (premises, campus, outside plant (OSP, etc.). So it is very important to know about the OSP planning and Design Procedure.

The OSP Planning and Design of the network must precede not only the installation itself, but it must be completed to estimate the cost of the project and, for the contractor, bid on the job. OSP Planning and Design not only affects the technical aspects of the installation, but the business aspects also. OSP Planning and design provide the proper connecting buildings over distances as short as a few hundred meters to hundreds or thousands of kilometers. Data transfer rates for telecom network are typically 2.5 to 10 gigabits per second using very high power lasers that operate exclusively over single mode fibers.

OSP Planning & Design


Now I will explain in short about the planning objectives,Planning standards etc. I hope that it will provide the more technical support for OSP planning and Design to built optical network.

For the Local Access Network, the objectives are to:-
maximize the use of the existing network
minimize the number of unused pairs
 ensure the subscriber is provided with a fault free network
 ensure the efficiency of O&M, eliminating unnecessary work and minimizing costs
provide sufficient new plant of a type that satisfies the needs of Subscribers.
optimize the use of fiber optic in the access network.

The application of these planning standards vary according to operators,
depending on the local objectives for the following:
Ultimate lines per dwelling unit
Provisioning period for secondary cable
Provisioning period for primary cable
 Provision of appropriate supporting structures
Provision of type of services offered to or required by subscribers.

For copper networks and to maintain administrative integrity, thorough planning of the location and perimeters of each exchange area is imperative.

A cabinet area is a geographic area within which all secondary cable is brought to a single cabinet for cross-connection with the primary cable. 
The objective in designing a cabinet area is to find the most economical balance of costs between the ultimate secondary plant and providing primary plant on an incremental basis. The size of each cabinet area should be optimized within economic, transmission and line plant limitations.

Some services such as ISDN and similar will reduce the future demand for copper pairs and increase the requirements for fiber optic in the network. Some broadband services may require the use of fiber optic cables for provision to Remote Access Nodes(RANs) which are located in CSAs. The CSA design places the RAN close enough to the subscribers to provide digital services such as ISDN and 2MBit/Sec data channels over the copper pairs without further work.

The local access network is that part of a telecommunications network which connects the subscribers with their dedicated switching facility.The existing access network of operators contains the following elements.Traditional flexible copper network from local exchanges.
Flexible copper networks connected to fiber fed remote access nodes of varying types.Fiber fed RANs placed inside major commercial centers and connected directly to the customers network. HDSL facilities fed over existing copper primary cables (PGS) to existing cabinets. Wireless in the Local Loop (WLL) connected direct to customers telephones.It is expected that the evolution to fiber fed access solutions will form the basis of future developments.

The use of primary cables feeding cabinets to which secondary cables are normally connected leads to maximum use of the primary cables, maximum use of duct space nearer to the exchange (which is generally the most expensive) and gives flexibility in the network to accommodate sudden pockets of demand at minimum cost.The switching hierarchy in the local network and its relationship to the national switching network.
The local access network comprises all the plant and equipment necessary to provide subscribers lines from the telephone exchange Main Distribution Frame (copper network) or the appropriate terminal equipment when served by optical fiber or radio via a Remote Access Node, to the Subscribers Terminal Block, inclusive.

Duct systems, pole lines and cable vaults in the local area are part of the outside plant. Pressurization equipment for use in the local network is part of the outside plant.Outside Plant also includes cable networks for long distance circuits, junction circuits, pair gain systems and RAN's in the local area.

Long Term Planning is the continual process of reviewing, revising and updating the telephone system based on operators policies. A long term plan is required to obtain an overall picture of the future for budgeting purposes and to prepare for projects in the years following immediate construction programs.
-It involves checking existing facilities and growth forecasts to determine what, when and where additional facilities will have to be added in the future to the existing network to allow for expected demand for growth and for new types of service.

-Failure to co-ordinate the design, construction and maintenance activities of the Local Access Network with other proposed developments, e.g. switching provision, can result in failure to provide key elements of the network at the correct time, at an insufficient level of provision, below an acceptable standard and at a very high cost; all of which can impair the operators revenue earning capability from the network.

-Many outside influences such as municipal authorities who initiate road projects or must provide approval for telephone projects, new development or redevelopment, etc., may require the planner's initial plans or ideas to be redesigned due to the timing or size of these outside influences.

-The end result of Long Term Planning should be to define and record fundamental Primary Areas and routes. This will form the basis of the Outside Plant Plan and will provide guidelines for defining the initial construction program.
-It is within this plan that the detailed design of local access networks takes place.

The basis of the Outside Plant Forecast is the General Planning Forecast which is prepared for each Local Switching Center Area. Depending on the nature of the Switching Center Area, revisions to the General Planning Forecast may occur only once a year for slow growth Switching Center Areas, or several times yearly for active Switching Center Areas.
The General Planning Forecast is supported by basic assumptions relating to items such as:
 General economic conditions.
General business conditions.
Rate of commercial, industrial and residential expansion.
Community planning, zoning and land values.
 Changes in community character or economic status of its inhabitants.
 Fringe area growth.
 Construction of, or major changes in, transportation facilities

Development of a specific forecast requires the Forecaster to assemble reference material and assimilate the various inputs into a cohesive individual forecast.

The following is typical reference material which would be used:
Material from Forecast Files
 Current General Planning Forecast
 Previous forecasts (for the same Primary Route)
Special services forecast
Topographical maps
Zoning maps
 Aerial surveys (to show buildings and vacant land)
Building reports
Digitized maps
News clippings
In service count by cabinet area (current and historical)
Maps showing local switching center area, primary area, and engineering forecast area boundaries.
Advice of potential residential, commercial and industrial developments..


Access network planner is not responsible for other line plant functions, the “Access” network may require input by third party references. Input during detailed design activities considered as important information for the fine-tuning of the current plan.The final planning recommendations may be used as input for the preparation of a development budget.

The reliability of the Access Network is vital since a high percentage of all subscriber complaints are due to outside plant defects. It is the combined skills of the outside plant planners, the designers, the construction personnel and the materials approved for use in the network that are prime factors in ensuring that the network will service the needs of the subscribers. In developing the plans for the network the planners will need to take account of all factors which will influence the operation and maintenance of the network during its service lifetime.

There is a requirement to develop the Access network utilizing the most suitable technology that is available taking into account trends in the development of available electronics, transmission bearers and the services to be provided.

With the increased rate of change in the field of remote switching and pair gain systems there is a high probability of the electronic subscriber interface being located nearer the subscriber. This will have significant impact on the type of access network provided. Careful consideration must be given to the integration of these facilities to ensure minimum customer disturbance while obtaining maximum benefit from the advances in technology.

Provision of a network which will enable service to be given on demand during the planned life of the network with the minimum of additional expenditure;

Provision of the network as economically as possible consistent with sound engineering design, utilizing the existing network to the best advantage;

Ensure that both the Duct and Cable are planned to satisfy the following technical requirements:-

(i) transmission and signaling limits as laid down in the transmission plan;
(iii) civil engineering and electrical engineering specifications.


Subscriber Radio Systems (SRS)
These systems are generally used to provide standard telecommunication services and others such as telex data etc., to widely scattered rural subscribers located beyond the transmission limits of existing local exchanges. In some cases there will be a requirement for cable plant to be connected to the system via a cross-connection point, to provide the final link to the subscriber. Each system has a capacity of approximately 350 subscribers

Remote Switching Units
Can be placed in the network to satisfy a demand which is in excess of a typical multiplexer. The remote switching unit is effectively a “mini” exchange with all the normal facilities and comes in a range of sizes from around 700 line units and upwards of 2,000. They can be placed in cabinets, containers or in suitable accommodation provided in a commercial building

Can be placed outdoors in the network where there is a density of subscribers who will have a high usage rate of the facilities on offer and where a greater bandwidth other than the standard is required. All subscribers will have access to all facilities at the same time if required. Multiplexers can be located in a building or at a road side cabinet.

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