PON Design

Understanding PON Design FTTx Overview/Glossary

1 of 57

Understanding PON Design

FTTx Overview/Glossary/Acronyms


2 of 57

FTTx Overview Fiber-to-the-x (FTTx) can be described using a number of optical fiber architectures. This section will briefly describe the following architectures:

Fiber-to-the-Premise (FTTP)

Fiber-to-the-Home (FTTH)

Fiber-to-the-Business (FTTB)

Fiber-to-the-Curb (FTTC)

Fiber-to-the-Node (FTTN)

FTTx is also discussed in the context of deployment scenarios such as Greenfield, Overbuild, Rehabilitation and Hybrid architectures.

General descriptions are offered for products and accessories for which actual design considerations may be built.

The next generation of broadband access networks must be able to provide the needed bandwidth for current demands as well as that for any future applications.

Optical fiber provides but one solution for existing and future requirements. With optical fiber technologies, bandwidth demands are satisfied, bringing the communications infrastructure more powerful tools that can interface directly with homes, businesses, offices, community centers, and government agencies. Optical fiber technology provides a higher capacity data transfer at very high speeds. This enables the community or service provider to supply a wide range services and applications, such as High Definition TV (HDTV), Video on Demand (VoD) and high-speed data all while providing the basic fundamentals of voice connectivity.

Broadband Access equipment providers are able to offer technology advances through the converged services of triple-play features using network aggregation and subtending in combination with the passive optical network (PON) technology.

The following is a partial list of advantages in using optical fiber systems: - Higher Bandwidth Capacity - Resistance to Outside Interference - Longer Reach - Lower Maintenance Costs - Longer Life - Better Reliability Communities and service providers are able to offer a wide range of value-added services, above and beyond existing services over a fiber optic infrastructure.

Fiber Access Overview Communities and service providers have responded to the growing demand for broadband services by either moving towards a wireless solution or upgrading their existing copper infrastructure with xDSL technologies. Both of these technologies are readily available today, and represent a natural evolution to more applications and better utilization of their copper plants. But this is considered as an intermediate solution, due to rate limitations of wireless, and the transmission limitations of copper lines. Both technologies impose a technical trade off between rate and reach. This affects the number and types of services that can be offered by the service providers and communities. It is becoming more economical - and even more important - strategically imperative, for communities and service providers to start bringing fiber as close to residential and small business premises sooner, rather than later.


3 of 57

Exhibit 1: Schematic Diagram PON Network

Fiber-To-The-Premises (FTTP) though an emerging technology is not new. Fiber-to-the-Home (FTTH) has been commercially available for about ten years, and FTTP is viewed as the next logical step in the evolution of the access network. In an FTTP architecture, an optical fiber is deployed all the way to the customers premise or location; either to the residence (FTTH - Fiber To The Home) or to a business (FTTB - Fiber To The Business). Exhibit 1 above is an expanded view of the components that comprise the Passive Optical Network (PON) between the Optical Line Termination (OLT) at the central office (CO) and the Optical Network Termination (ONT) at the home. Most of the active equipment providers have similar components that provide similar services. Basically, the Optical Line Termination (OLT) takes an electrical signal from a particular content, converts the signal into an optical signal, and then transports that signal down through the network. There are two downstream optical wavelengths, 1550 nm for a video overlay, and 1490 nm for traditional voice and data services. There may or may not be a 1550 nm Video OLT (V-OLT) in the network: This is dependent upon whether you are providing video content through a video overlay (which is analog CATV Services) or switched digital video (SDV) (which is IP Video, not streaming video). If you are providing video through SDV, there will not be a V-OLT within the network. However, there will always be a Packet or Digital OLT (P/D-OLT) in the network as this is where your voice and data are transmitted and received. When using the video overlay techniques where the Video OLT is a separate set of electronics within the Central Office (CO) or Head-End (HE), there are new combining or mixing techniques that are needed to provide the upstream video on demand (VOD) services from the Central Office (CO) or Head-End (HE). Video on Demand (VOD) Techniques are discussed in the Video Training Module later in this course. The additional wavelength is the 1590 nm wavelength that provides the RF Return when the video overlay is used. This combining or mixing is accomplished with the use of the coarse wave division multiplexer (CWDM). So, What is CWDM (Coarse Wavelength Division Multiplexing)? CWDM is the technology for combining up to 18 International Telecommunications Union (ITU) wavelengths and transmitting them simultaneously onto a single fiber to be separated at the far end. The ITU standard for CWDM defines the 18 channels, 20 nanometers spaced, between 1271nm and 1611nm wavelengths. If there is a V-OLT, the 1550 nm and 1490 nm signals are combined through a Wave Division Multiplexer (WDM) module or CWDM and sent to the OSP fiber through the Main Distribution Fiber Frame to the Optical Distribution Network (ODN). The ODN serves as the access portion of the network. The fiber is spliced to the primary feeder fiber (F1) within the OSP which is connected or spliced to a centralized splitter

1490 nm DS Digital

1310 nm US Digital1550 nm DS Overlay

1590 nm US RF Return


4 of 57

housed within a Fiber Distribution Terminal or Hub (FDT or FDH). The cabinet containing the centralized splitter is also referred to as a Primary Flexibility Point (PFP), Local Convergence Point (LCP) or Fiber Service Area Interface (FSAI). The distribution fiber (F2) architecture may be centralized where all the F2 fiber extends from the FDH to the home, or distributed, where the splitting configuration extends at the FDH as well as the network access point (NAP) where the access terminals are located closer to the customer premise. The signals on the output of the splitter are distributed to homes or premises through the secondary or distribution fiber to a Fiber Access Terminal (FAT) that connects the Distribution Fiber to the Drop Cable terminating at the ONT. The fiber access terminal is also referred to as Network Access Point (NAP), and the ONT may be called a Network Interface Device (NID). The ONT must communicate upstream with the OLT. This is accomplished by an upstream 1310 nm laser within the ONT. The ONT converts the traditional voice and data electrical signals to an optical signal, and sends the optical signal through the same ODN through the WDM, which is finally received by the OLT. The OLT then converts the optical signal back into the corresponding electrical signals which is then processed. A Network Interface Device (NID) is located at the customer premise in the form of an Optical Network Termination (ONT), or Optical Network Unit (ONU). The ONT/ONU terminates the optical access network providing direct connectivity to the feature-rich services of voice, data, and video at the customer premise. The customer interfaces at the ONT comprise the transition from fiber to the customer premise wiring. These interfaces are as follows: RJ-45 10/100 Mbps Ethernet port for data (includes Voice over IP [VOIP] and Video over IP [SDV]), RJ-11 for voice, and F-Connector for video. In the early years, the high cost of building an all optical network limited deployments to new build or Greenfield areas. Just as infrastructure costs have decreased, and bandwidth needs have increased, communities and service providers are now recognizing the alternative solution to over build their networks with optical fiber. The initial investment required for optical fiber deployments is still fairly high and may require a proven return on a particular business case. A phase by phased approach is an alternative where the optical fiber access starts with a Fiber-to-the-Node (FTTN) or Fiber-to-the-Curb (FTTC) type of deployment either ADSL2+ or VDSL. In the FTTN/FTTC configurations, an optical link is deployed to a remote Digital Subscriber Line Access Mux (DSLAM) in a Service Area Interface (SAI) cabinet located near a residential community, subdivision or business setting. The DSLAM will convert the optical signal into an electrical signal where the services are easily transferred to existing copper facilities, and will interface directly with an ONU at the home. Due to the shorter reach of the copper infrastructure, service providers are able to offer higher bandwidth services without having to place the optical fiber directly to the premise. Future FTTP configuration upgrades can be economically justified, as a natural second phase, and/or service requirements grow. FTTN/FTTC are considered intermediate steps in providing broadband infrastructures. Greenfield

The ultimate FTTP deployment is the Greenfield scenario in newly built areas, where there is no existing broadband infrastructure and no constrictions exist. In new neighborhoods and planned communities, the application of FTTP is easy to justify as initial overheads are quickly repaid; the difference in infrastructure costs for fiber and copper is negligible, and construction costs are equivalent. Fiber greatly reduces future maintenance costs for the physical plant, thus it makes sense to deploy fiber to residences and businesses in Greenfield applications. Greenfield customers include:

Single-Dwelling Units (SDU) Multi-Dwelling Units (MDU). Small Business Units (SBU) Small/Medium Business Multi-Tenant Units (MTU).

Because of the nature of these new developments, a relatively high take-rate for second phone lines, data, and video services can be assumed, creating higher revenues and lowering the cost of deployment. Furthermore, due to the dense populations of FTTP customers in Greenfield applications, fiber can be cost-effectively run all the way from the CO to the Local Convergence Point (LCP), where the first passive split can be made.


5 of 57

Overbuild

The Full Overbuild scenario is an FTTP application. Where market demand for advanced data and video services exists in serviced neighborhoods, it may be desirable to deploy fiber along with the existing copper network. The following factors can contribute to a decision to overbuild an existing plant:

Aging infrastructure. Projected high take-rates. Competitive pressures. Requirement for higher bandwidths than that available with the current copper technologies.

The objective of the Full Overbuild with fiber is to gradually transition all customers to the FTTP system, while in concurrent, retiring the aging copper plant and the active infrastructure such as Digital Loop Carrier (DLC).

Rehabilitation

The Rehabilitation scenario aims to save expenditure when there is insufficient justification for such. The aim is identical to that of the Greenfield scenario, and all services are provided to all customer premises. The difference is that Rehabilitation involves existing customers, served with existing services, and over an existing copper plant. Voice and data services are provided on the copper network, and video on an existing coaxial network, if such exists. FTTP and FTTN can be installed in close proximity to customer premises. Should there be a need for a high-speed data, it can be provided from the FTTN network to requesting customers prior to a direct fiber build to the customer. Auditing Your FTTP Network Deployment Successful FTTP deployment begins with building a solid network foundation. Here, we examine the objectives of your FTTP deployment, your network infrastructure considerations, and the operational requirements you may face by asking informed questions: After youve completed this audit and carefully examined the important aspects of FTTP deployment, call 1-866-210-1122 and let ADC answer your tough questions. 1. Do you have plans to deploy FTTP, or are you considering deploying FTTP?

_ Deploying now _ In the next 6 months _ In the next year _ Considering

1. Have you chosen a Design Engineering consultant?

_ Yes (Name: ) _ No _ Need assistance

3. Is your FTTP deployment...

_ Greenfield _ Overbuild _ Own overbuild _ Competitor _ Refurbish _ Unknown

4. Have you chosen an active component supplier?

_ Yes (name supplier) . _ No APON ( ) _ Need assistance _ GEPON ( ) _ BPON ( ) _ GPON ( ) _ P2P Ethernet ( ) _ Active Ethernet ( )


6 of 57

5. Have you chosen a passive, outside plant (OSP) component supplier?

_ Yes (Name: ) _ No _ Need assistance

6. What business challenges lead you to consider FTTP? _ Increasing revenue/sales _ Retaining subscribers _ Supporting community quality of life _ Minimizing long-term maintenance costs by retiring copper plant _ Other ______________________

7. Have you built a business plan for FTTP? If so, what metrics do you target? (list metrics)

_ Revenue/subscriber (________________________) _ Cost/homes passed (________________________) _ MTTR- Mean-Time-To-Repair (____________ ___) _ Cost/truck roll (____________________________) _ Provisioning (______________________________) _ Other_______________________

8. Are you actively deploying other access technologies? Please check all that apply.

_ DSL _ Video _ Data services _ Voice services _ TI/T3 _ Wireless _ Satellite _ Other ___________

9. At what stage are your FTTP projects?

_ Activating service _ First office application and/or field trials _ Vendor selection _ Collecting information from vendors _ Securing funding/budgets _ Other ___________

10. What process will you use to select vendors?

_ RFI _ RFP/RFQ _ Sole source

11. What services will you offer over your FTTP network?

_ Voice _ TR008/GR303 _ Multiple lines _ T1/T3 (fractional T1) _ VoIP _ Video _ Video overlay with On-Demand/Pay-Per-View _ Video overlay without On-Demand/ Pay-Per-View _ QAM 256 _ Switched digital video _ HDTV _ IPTV


7 of 57

_ Data (tiered service levels) _ Security _ Meter reading (municipalities and utilities) _ Interactive gaming _ Other ___________

12. Which architecture type are you deploying?

_ Passive Optical Network (PON) _ Point-to-Multipoint _ Point-to-Point Ethernet _ Point-to-Point ATM _ SONET Ring _ Other ___________

13. Which overall approach do you favor for your OSP network?

_ Aerial _ Direct burial _ Above ground cabinet _ Above ground access terminal (pedestal) _ Unknown

14. Which additional considerations do you favor for your OSP network?

_ Splicing _ Connectorization _ Combination of both _ Unknown _ Other _____________

15. Have you chosen a splitter architecture?

_ Distributed/Cascaded _ Centralized _ Unknown

16. How many homes passed does your FTTP network serve when fully deployed?

_ 100 or less _ 101 to 500 _ 501 to 1000 _ 1001 to 5000 _ 5001+

17. What initial take-rate is expected?

_ 0% _ 1% to 25% _ 26% to 50% _ 51% to 75% _ 76+

18. How many total subscribers do you expect your FTTP network to serve when fully deployed?

_ 100 or less _ 101 to 500 _ 501 to 1000 _ 1001 to 5000 _ 5001+


8 of 57

19. If currently deploying, what percent of your potential subscribers are currently turned up? _ 0% _ 1% to 25% _ 26% to 50% _ 51% to 75% _ 76+

20. How would you rate the current state of fiber expertise among your technicians?

_ Excellent: They are thoroughly trained in FTTP and understand the nuances of fiber optic cable management and slack storage.

_ Fair: While some are experienced in FTTP, many technicians lack familiarity with the technology. _ Poor: We need to thoroughly train most of our staff in FTTP.

21. If you could offer FTTP now, what take-rates would you anticipate?

_ Less than 10% homes passed _ 10% to 24% homes passed _ 25% to 49% homes passed _ 50% or greater homes passed

22. What environmental extremes will your network face?

_ Temperature extremes _ Flooding _ Earthquakes/seismic activity _ Snow/ice _ Unknown

What would you say are the most critical FTTP challenges for you to overcome?

1.

2.

3. 23. What right-of-way constraints or community covenants impact your infrastructure options? (i.e. moratorium on above ground facilities, ROW federally mandated)

1.

2.

3.


9 of 57

FTTH Council - Definition of Terms

Revision Date: August 2008 INTRODUCTION The mission of all the FTTH Councils in North America, Europe and Asia-Pac includes the communication to stakeholders in our respective regions of the extent of usage of FTTH throughout the world and forecasting the growth of FTTH. This task has been made difficult by the proliferation of terms and acronyms that, while no doubt useful to individual organizations for their specific purposes, lack precise definitions. This is of particular concern when different research organizations choose their own definitions when conducting research. As a consequence it becomes impossible to compare the research on FTTH between different regions, or between different studies of the same region. This document defines the terms used by all the FTTH Councils (North-America, Europe, Asia-Pacific). To promote consistency when commissioning or commenting on research the Councils members will confine themselves to those terms defined in this document. This document specifically aims to reduce the terms used to a subset that are well defined, adequate and useful. THE TERMS Fiber-to-the-Home (FTTH)

Fiber to the Home is defined as a telecommunications architecture in which a communications path is provided over optical fiber cables extending from the telecommunications operators switching equipment to (at least) the boundary of the home living space or business office space. This communications path is provided for the purpose of carrying telecommunications traffic to one or more subscribers and for one or more services (for example Internet Access, Telephony and/or Video-Television). This definition excludes architectures where the optical fiber terminates in private space before reaching the home living space or business office space and where the access path continues to the subscriber over a physical medium other than optical fiber (for example copper loops). This definition excludes architectures where the optical fiber cable terminates in public space (for example an operators street-side cabinet) and where the access path continues to the subscriber over a physical medium other than optical fiber (for example copper loops). It is acknowledged that other parties such as the US FCC make specific concessions for such architectures. However, for the formal communications of the Councils, architectures that are excluded by this definition are NOT Fiber-to-the-Home.

Fiber-to-the-Building (FTTB)

Fiber to the Building is defined as a telecommunications architecture in which a communications path is provided over optical fiber cables extending from the telecommunications operators switching equipment to (at least) the boundary of the private property enclosing the home or business of the subscriber or set of subscribers, but where the optical fiber terminates before reaching the home living space or business office space and where the access path continues to the subscriber over a physical medium other than optical fiber (for example copper loops).


10 of 57

FTTB construction is a transitional form commonly used as a means to deliver services to existing buildings in conjunction with associated FTTH construction (for example for new buildings). By introducing fiber cables from the fiber termination point to the home living space or business office space FTTB can be converted to full FTTH. Such a conversion is desirable as FTTH provides better capacity and longevity than FTTB. This communications path is provided for the purpose of carrying telecommunications traffic to one or more subscribers and for one or more services (for example Internet Access, Telephony and/or Video-Television). This definition excludes architectures where the optical fiber cable terminates in public space (for example an operators street-side cabinet) and where the access path continues to the subscriber over a physical medium other than optical fiber (for example copper loops). However, for the formal communications of the Councils, architectures that are excluded by this definition are NOT Fiber-to-the-Building.

Cable Plant Topology

The cable plant which connects the operators premises and subscribers premises can be deployed in the following different topologies: Point-to-Point (P2P) cable plant provides optical paths from the telecommunications operators switching equipment to a single contiguous location such that the optical paths are dedicated to traffic to and from this single location. In generic terms this is a star topology. Point-to-Multipoint (P2MP) cable plant provides branching optical paths from the telecommunications operators switching equipment to more than one contiguous location such that portions of the optical paths are shared by traffic to and from multiple locations. In generic terms this is a tree topology. Ring cable plant provides a sequence of optical paths in a closed loop that begins and ends at the telecommunications operators switching equipment and connects a series of more than one contiguous location such that portions of the optical paths are shared by traffic to and from several locations. A location is identified as being within the boundaries of the private property enclosing the home, business or premise of the subscriber or set of subscribers. Note that from these definitions it is not possible to identify the access protocol used over the cable plant. It is possible for a network to be built so that a common cable plant can include a mix of different topologies, or be re-configured over time to support different topologies, to allow for mixed user categories, to allow access diversity for reliability, and for future flexibility and network longevity.

Access Protocol

Access Protocols are the methods of communication used by the equipment located at the ends of the optical paths to ensure reliable and effective transmission and reception of information over the optical paths. These protocols are defined in detail by the standards organizations that have created them, and are recognized and implemented by manufacturers around the world. These definition of terms are to be used primarily within a Passive Optical Network (PON) where there are no or limited active components in the field. Networks may be passive where remote huts or cabinets are placed within a protected ring architecture and fiber may extend from these locations directly to the subscriber premises.


11 of 57

The Access Protocols in use today for FTTH Networks and the optical portion of FTTB Networks are: EFM defined as Ethernet in the First Mile or Ethernet over P2P 100baseFX, 100baseLX, 100baseBX, 1000baseLX and 1000baseBX in IEEE 802.3ah GEPON defined as Gigabit Ethernet PON 1000basePX in IEEE802.3ah BPON defined as Broadband PON in ITU-T G.983 GPON defined as Gigabit PON in ITU-T G.984 WDM PON defined as a wavelength PON, not fully ratified under ITU-T at this time. Standards are being reviewed. OTHER access protocols such as proprietary or pre-standard access protocols may be noted for the purpose of completeness in research.

Network Usage

FTTH/FTTB Networks may be dedicated to the services of a single retail service provider, or made available to many retail service providers, who may connect to the network at the packet, wavelength or physical layer. Exclusive Access refers to the situation where a single retail service provider has exclusive use of the FTTH network. Open Access (Packet) refers to the situation where multiple retail service providers may use the FTTH Network by connecting at a packet layer interface and compete to offer their services to end users. Open Access (Wavelength) refers to the situation where multiple retail or wholesale service providers may use the FTTH Network by connecting at a wavelength layer interface and compete to offer their services. Open Access (Fiber) refers to the situation where multiple retail or wholesale service providers may use the FTTH Network by connecting at a physical layer (dark fiber) interface and compete to offer their services. Open Access (Duct) refers to the situation where multiple retail or wholesale service providers may share the use of a duct network covering a substantial region by drawing or blowing their fiber cables through the shared ducts, and compete to offer their services.

User Categories

FTTH/FTTB Networks may deliver services to the following categories of users: Residential refers to private users in their homes. Residential users may live in MDU (multi-dwelling units such as apartments/condominiums) or SFU (single family dwelling units such as stand-alone houses/villas/landed property). Business refers to large (corporate), medium, and small (Small Business, Small Office Home Office) business users. Businesses may occupy MTU (multi-tenanted units such as office blocks/towers) or STU (single-tenanted units such as a stand-alone office building or warehouse).


12 of 57

NETWORK SIZE

The size of FTTH/FTTB Networks is described in the following terms: The number of Homes/Premises Passed is the number of residential and business premises to which an operator can currently deliver FTTH access within the operators standard service activation period (for example 30 days) should the owners/occupiers sign a contract for an access service. Typically new service activation will require the installation and/or connection of a drop cable from the street or basement to the home or office, and the installation of subscriber premises equipment. The network that is determined to be drop ready is considered to be a Homes/Premises Passed. This definition excludes premises that cannot be connected without further installation of substantial cable plant such as feeder and distribution cables to reach the area in which a potential new subscriber is located. The number of Homes/Premises Connected is the number of residential and business premises to which an operator is supplying FTTH access under a commercial contract. The Take-up Rate or Take Rate for a network is calculated by the simple division of Home/Premises Connected by Home/Premises Passed, and is expressed as a percentage.

SERVICES

FTTH/FTTP Networks are used to deliver the following services: Internet refers to use of the Public Internet for exchanging email, web-browsing, etc. Voice refers to the exchange of human conversations by use of IP or Other encoding and transport protocols. (This category does not include Voice carried over the Public Internet.) Video refers to the exchange of visual material by use of IP, RF (carried via a separate optical wavelength) or Other encoding and transport protocols. (This category does not include Video carried over the Public Internet.) Internet Video Internet video is defined as any video being delivered using IP protocols over the internet. The video can range from download to streaming content. The video can also come in many forms ranging from standard MPEG2 and MPEG4 to WMV, AVI and MOV. It could also include raw digital video. The video can be supplied by any server on the internet. Most of these systems are open and available to anyone on the internet. Some may require membership or user login. IPTV (IP-based TV) The transmission of TV programs from private Internet providers such as cable and telephone companies or from a Web site using IP protocols over an IP network. Also called "TV over IP" or Video over IP, IPTV uses streaming video techniques to deliver scheduled TV programs. Unlike transmitting over the air or via standard cable to a TV set, IPTV uses the IP protocol as the delivery transport and requires a users device (Set Top Box or Mobile Video Device) to decode the images in real-time. In the IPTV environment, the user only receives the channel that is being viewed. IPTV Broadcast Video (IBV) A set of network devices that encode broadcast channels, such as ESPN, CNN, History Channel, network broadcasts (ABC, NBC, CBS, Fox, PBS, etc.), Discover Channel, Disney, etc., using MPEG2 or MPEG4 encoding and distributed using IP multicast protocols over an IP network. These IP streams are transported over a broadband connection to the user and decoded at the users device (Set Top Box or Mobile Video Device). The multicast


13 of 57

streams for a specific broadcast maybe different for the STB and the Mobile Video device. This would allow the BVS to provide encoding for a specific type of device. IPTV Distribution System The system used to distribute IPTV channels from the Broadcast Video Server to the end users. The system consists of the headend (video acquisition system, encoders & video on demand servers), content management & Digital Rights Management (DRM), and IP fiber backbone & edge routers. The distribution system also includes a set of protocols used for content delivery to the end user. These protocols can be open, standard, proprietary, or a combination. This system is closed and available only to subscribers. Personal Video Recorder This is a device that allows trick plays on live content by recording all content to a hard drive. May be local (in the Set top) or in the network. Initial offering by TiVO. Video on Demand (VoD): Video on Demand systems allow users to select and watch stored video content over an IP network as part of an interactive television system. VOD systems are either "streaming", in which the video is streamed over the IP network to the user, or "download", in which the program is downloaded in its entirety to the users device (Set Top Box or Mobile Video Device) before viewing starts. VoD uses unicast IP protocols to deliver the Video to the end user. Video on Demand systems allow the user to pause, fast forward, fast rewind, slow forward, slow rewind, jump to previous/future frame etc (trick play) Applications other than those listed above are categorized as Other.

CONCLUSION The intention of this document is to make it possible for Council Members and the FTTH industry to speak a common language when discussing FTTH statistics and network characteristics. No doubt Council members and other stakeholders will feel the need to use a wide range of terms for technical solutions, concepts, and models. This document does not discourage this activity, as it is inherent in the free flow of communication on which our industry thrives. However to be successful, the terms defined in this document must be used frequently and consistently. Thus all Council Members and other stakeholders such as operators, analysts, journalists, and government and regulatory staff are encouraged to use these terms as the well-defined vocabulary that underpins the more general expressions. With regards to Market Research however, in order for research by different organizations conducted in the same or different regions to be meaningfully compared, it is essential that these terms are used and no others.

Design Questions


14 of 57

Typically with any change in infrastructure, there are a number of assumptions or design questions that will arise. Below are only a few:

1. How many homes do you plan to serve out of each local convergence PON cabinet? Is the Serving Area Greenfield or Overbuild Area? If this is an Overbuild Area, are you overbuilding yourself or your competitor? Is the Serving Area a single family or multi dwelling development or mix? For Greenfield applications, is the Serving Area being developed in phases? What is the total Serving Area Size? Are the Serving Area Size and Distribution Area (DA) Size the same? (If different,

explain.)

2. Are you planning on sparing any fibers for the Feeder (F1) Fiber and/or the Distribution (F2) Fiber? For Feeder Fiber sparing, there is no rule-of-thumb for count and size. Typically, the

sparing in the feeder fiber is accomplished by capitalizing on the buffer tube count. (i.e. The PON Cabinet that serves 216 subscribers. For this style of Cabinet, you would need 6.75 feeder fibers [216/32=6.75]. You will probably use some sparing of the Distribution (F2) fiber so in providing services for say, 192 subscribers, you will need only six (2) Feeder (F2) Fibers. However, connectorized and/or splice input feeder trays accept twelve (12) fibers (one buffer tube), and the buffer tube fiber count is generally twelve (12) fibers. Here, you would use this count, six (6) fibers for the distribution serving area (SA), and six (6) fibers as spare.)

Service Providers today use sparing within the distribution (F2) on the order of 1.125 to 1.5 fibers per subscriber. Cabinets can be sized at 1.2 fibers per home (In some cases, up to 1.5 fibers per home.) (i. e. Example 1: The Cabinets that have two (2) 72-port pre-terminated panels for 144 distribution fibers. The centralized splitter configuration calls for four (4) 1x32 splitter couplers which will account for 128 subscribers. Here, we have 1.125 fibers per subscriber. Example 2: Another Cabinet has three (3) 72-port pre-terminated panels for 216 distribution fibers. The centralized splitter configuration calls for six (6) 1x32 splitter couplers which will account for 192 subscribers. Here again, we have 1.125 fibers per subscriber.) In both Example 1 and Example 2, the service provider is sparing within the cabinets. Some sparing may actually be in the distribution (F2) fiber itself. In Example 2, the cabinet supports 216 subscribers (only 192 subscribers used), where the distribution (F2) fiber count may be a 288-count fiber. Here, this will show 288/192=1.5 fibers per subscriber.


15 of 57

Additional Assumptions and/or Questions for FTTx Projects With any project in the Outside Plant, additional assumptions may need to be understood. Below are just a few assumptions that may arise during the initial design stages.

- Is this a green field location with few placement obstacles? - What are the RW restrictions? - Very few placement restrictions all Rights of Way (RW) are open for front and rear cable

placements. - Is cable placement along the interstate highway considered as a useable path? - Will above ground pedestals or below ground terminals be used for distribution cabling and drop

cables? - Will the drop cables will be connectorized or spliced at the pedestals? - Will 8, 10 or 12 pedestals be used at the drop locations? - Will 12 pedestals will be used at drop/splice locations? - Will multi-fiber service terminals will be used at the drop locations? - For single family homes and town homes, how many spare fibers per residence? - Will each townhouse unit will be served individually or with MDU electronics? - Will the drops to the residential homes be placed from pedestals directly to each home? - For the business and industrial locations Assume that at least two fibers are available for each lot

and approximately 1 spare per terminal. - Are copper facilities planned or needed in the development? - What is the distance of the feeder (F1) cable from the central office to the fiber distribution terminal

(local convergence point)? - Is the serving area (SA) fed by the feeder (F1) cable only, where no additional cables are placed

for large scale additions in the area Is this area the end of the central office boundary? - Assume that common sized cables are used for better pricing (12, 24, 48, 96, 144, 218, 288, 384) - Assume that the cable count shown as an example of 24 F cable (i.e. 1-12 , 12DD) cable has 12

fibers active and 12 dead - For the video service solution, will the video be IP video or video overlay (RF Video)? - Is this a field trial? (equipment available? when needed in 2006/2007?) - All initial cost shown on the spread sheet are list prices. - Total pricing is based on total IP solution or mix. - Assume that the take rate for services are between 25%-30%. - What is the take rate for services? - The developer and/or service provider are committed to provide all home owners services, 100%

whether they use them or not. - What is the type of infrastructure placements? Buried, aerial, using above ground pedestals or all

out of sight below ground? - Is joint trenching with power company or others available? - 1 foot minimum separation from buried power cables. - 40-inch separation from the neutral for aerial cable placement. - Is locating drop cables a needed capability? - Are pass through capabilities needed? For business or special offerings. - Is your PON design for EFM, GEPON, BPON, GPON or WDM PON Design solution? - Are you designing the network for Active Ethernet? - Who is the active component provider (OLT/ONT)?


16 of 57

Telcordia Reference Model The governing body of BellCore (Telcordia) has determined through GR-909 that specific definitions and practices for FTTH should be followed. Below are the most current definitions provided by Telcordia.

Telcordia Reference Model for FTTH

Exhibit 2. Reference Architecture from Telcordia GR-909 Release 2005

Telcordia Reference Definitions

Application Environment: Residential and Small Business (large multi-dwelling unit and multi-tenant unit applications may be added in future.) From an earlier slide detailing end customers, for the residential community, the Segments, Services and Interfaces will include the Single Family and MDU Markets, while the business community will include the Retail and MTU Markets.

ONT Definition: An ONT is an ONU which is the customer network interface device (NID)

located on customer premises that serves a single LEC customer. ONT Ownership: ONTs are network equipment owned by the LEC, but in the future, may

become part of the customer-owned equipment. ONT Powering: Primary and backup powering of ONTs is provided by the customer.


17 of 57

Digital Video Support with an Analog Video Overlay: If an analog video overlay is supported, digital video services will by provided via sub-carrier multiplexing on the AM-VSB system and not using baseband digital video transport on the FITL system. The RF Return can be provided as an IP return for VOD services.

FTTB Definition Fiber-to-the-Building, here the ONU is either attached to or located within a

building and serves multiple LEC customers. Applications include residential multi-dwelling unit (MDU) and business multi-tenet unit (MTU) buildings.

CABLE AND DROP WIRE SELECTION PROCESS Cable Design Considerations In order to select the correct fiber optic cable design for ones planned application, the following should be asked and determined: Is the planned infrastructure to be aerial, buried, or underground plant, or a combination of two, or all three? Is there a preference to use a dielectric cable or a metallic cable? Then ask and determine: Are there specific cable designs for each type of plant infrastructure? The answer is no! The present day cable construction, both dielectric and metallic, can be used in aerial, buried, or underground plant. The choice between Dielectric and metallic. The dielectric cable requires no protection from foreign voltages, lightning strikes, etc., plus the sheath preparation time is much less than metallic. The metallic cable design requires the application of bonding and grounding hardware to provide a field of safety for those who work on these cable sheaths, as well as protection of the electronic equipment that the cable connects to on each end. The selection process for feeder, backbone/trunk, distribution cables, and the connecting drop wire.

FEEDER CABLE In making the first step toward selecting the proper feeder cable design, what are the key considerations?

A. When high-count fiber cables are required (such as 144 fibers to 864 fibers) the DriTube ribbon cable design will provide high productivity when applied with the mass fusion splicing method. It will also utilize minimal splice closure space.

B. Fiber requirements below the 144f count can be packaged in a DriCore loose-tube design. The

benefits of mass fusion splicing can still be attained in using this cable, by applying the ribbonizing method to the individual fibers contained within the buffer tubes.

C. The central office or head-end patch-panel terminations are best served by being equipped with DriTube ribbon cables, in both an FT-4 cable design (OFNR) (Sumitomo) and an Indoor/Outdoor cable design. The use of this cable design will enhance productivity of labor through the mass fusion splicing method.


18 of 57

BACKBONE/ TRUNK CABLE As one gets deeper into the network, the use of backbone / trunk cables (96 fibers to 288 fibers) is utilized to distribute the feeder fibers. This cable can serve as a combination backbone / trunk cable and a distribution cable. When selecting the correct cable design for this application, the following should be considered.

A. When deploying any type of cross-connect housing, splitter housing, etc., most stubs from these types of apparatus are equipped as ribbon cable. Here again the benefits of mass fusion splicing are achieved when the backbone / trunk cables meet the stubs of these units.

B. The design of the distribution terminals that are being deployed in concert with the stubbed

products, will also have an impact on selecting the cable design to use in the backbone / trunk application. Those terminals with ribbon fanouts will mate well with ribbon cables, while those terminals equipped with single fusion pigtails (when less than four pigtails) will mate well with loose-tube cables.

DISTRIBUTION CABLE Within the deepest area of the network lies the distribution area, where fiber counts of 12 to 72 fibers are typical. In determining which cable design to apply, ribbon DriTube, Loose-Tube DriCore, or filled central tube Bundle cable, the design of the terminal and its splicing method should be considered. The following information should be relevant in selecting a cable product:

A. Aerial Taut Sheath Splicing. In selecting a loose-tube cable for this application, the spacing of and the identification method for the ROL (reverse oscillation lay) of the buffer tubes, is important. The unraveling of the buffer tubes at the ROL will provide the maximum in fiber slack during the splicing operation.

B. In using the ribbon product in this scenario, there is no need to locate a rol-type location. When

compared to the buffer tube accessing operation, the ribbon design yields less fiber slack. The access time to reach fibers in the loose-tube and ribbon cable is about the same.

C. When selecting the filled central tube bundled cable, here again there is no need to locate a rol-

type location. There is also no need to spend time accessing packaging such as a buffer tube or ribbon, to get at the individual fibers. The fiber slack yield is comparable to that of loose tube cables.

Slack Available in Aerial, Buried, and Underground Splicing Operations. Where cable slack is provided during the placing operation, the choice of loose-tube , ribbon, or bundled cables is influenced by the following:

A. Splice closure or terminal design. Fanout or pigtail, plus storage capacity.

B. Single fusion or mass fusion (4,8,&12 fibers)

C. The need for fiber access tools. FIBER DROP WIRE, 1 TO 12 FIBERS The final step in building an FTTP / FTTH connection is to select the proper drop wire for use in this application which brings the customer to the service structure. The choices are as follows:

Aerial self-supporting drop wire - Aerial dielectric drop wire Buried dielectric drop wire - Locatable buried drop wire


19 of 57

The termination methods of pre connectorized; raw-end splice to fiber; raw-end splice to pigtail; are all common with the four designs listed above. For aerial drop wire applications, the following information must be known.

What storm loading area applies? Heavy, medium, or light. What span lengths are there to be met? What flammability standard is required? What is the attachment hardware preference? What sheath access tools are required? What are the bonding and grounding requirements of the area?

For aerial spans, the following applies.

Heavy storm loading area, self-supporting span maximum is 300 feet, and the dielectric maximum is 75 feet.

Medium storm loading area, self-supporting maximum is 500 feet, and the dielectric maximum is 150 feet.

Light storm loading area, self-supporting span maximum is 750 feet, and the dielectric maximum is 250 feet.

Self-supporting drop wire design requires a wire-vise type attachment hardware along with insulation hardware.

Dielectric drop wire requires a clamping-type device for attachments. For the buried drop wire application, which can be plowed, trenched, or pulled into conduit, the following is information that should be known when selecting between the two designs.

Is the drop wire required to be locatable? If the drop wire is not required to be locatable, the standard dielectric drop should be selected.

Enabling Technologies for PON Due to the topology of PON, the transmission modes for downstream (i.e., from OLT to ONT) and upstream (i.e., from ONT to OLT) are different. For the downstream transmission, the OLT broadcasts optical signal to all the ONTs in continuous mode (CM), i.e., the downstream channel always has optical data signal. However, in the upstream channel, ONTs can not transmit optical data signal in CM. It is because that all the signals transmitted from the ONTs converge (with attenuation) into one fiber by the power splitter (serving as power coupler), and overlap among themselves if CM is used. To solve this problem, burst mode (BM) transmission is adopted for upstream channel. The given ONT only transmits optical packet when it is allocated a time slot and it needs to transmit, and all the ONTs share the upstream channel in the time division multiplexing (TDM) mode. The phases of the BM optical packets received by the OLT are different from packet to packet, since the ONTs are not synchronized to transmit optical packet in the same phase, and the distance between OLT and given ONT are random. Besides the characteristics of random phases in the burst mode packets, the other issue is about the amplitudes of the received packets. Since the distance between the OLT and ONTs are not fixed, the optical packets received by the OLT have different amplitudes, supposing the transmitted optical powers of the packets at ONT sides are similar. In order to compensate the phase variation and amplitude variation in a short time (e.g., within 40 ns for GPON), burst mode clock and data recovery (BM-CDR) and burst mode amplifier (e.g., burst mode TIA) need to be employed, respectively. Furthermore, the BM transmission mode requires the transmitter works in burst mode, and such burst mode transmitter shall be able to turn on and off in short time. The below three kinds of circuitries in PON are quite different from their counterparts in the point-to-point continuous mode optical communication link.


20 of 57

PON Glossary Below is a glossary of terms that are frequently used within the PON environment. It contains many of the terms also associated with various parts of the Access Network of which PON is one type. Access Network The method, time, circuit, or facility used to enter the network. The service provided by local exchange carriers or alternate access providers, which connect an interexchange carrier with its customers. The Access Network today is predominantly passive twisted pair copper wiring. ADM Add/Drop Multiplexer capable of extracting or inserting lower-bit-rate signal from a higher-bit-rate multiplexed signal without completely demultiplexing the signal. ADSL Asymmetric Digital Subscriber Line transmits data asymmetrically meaning the bandwidth usage is much higher in one direction than the other. Typical ADSL applications transmit 8 Mbps downstream and 768Kbps upstream, depending on the length of the local twisted pair loop. This is particularly beneficial for residential Internet access, remote access and video on demand because downstream usage far exceeds upstream usage. ADSL2+ Asymmetric Digital Subscriber Line Two Plus (ADSL2+) extends the capability of basic ADSL by doubling the number of downstream bits. The data rates can be as high as 24 Mbit/s downstream and 1 Mbit/s upstream depending on the distance from the DSLAM to the customer's home.

ADSL2+ is capable of doubling the frequency band of typical ADSL connections from 1.1 MHz to 2.2 MHz. This doubles the downstream data rates of the previous ADSL2 standard of up to 12 Mbit/s, but like the previous standards will degrade from its peak bitrate after a certain distance.

Also ADSL2+ allows port bonding. This is where multiple ports are physically provisioned to the end user and the total bandwidth is equal to the sum of all provisioned ports. So if 2 lines capable of 24 Mbit/s were bonded the end result would be a connection capable of 48 Mbit/s. Not all DSLAM Vendors have implemented this functionality. ADSL2+ port bonding is also known as g.998.x or g.Bond

APON An Asynchronous Transfer Mode (ATM) based Passive Optical Network (PON). ATM Asynchronous Transfer Mode is a connection-oriented service that segments data into a succession of small units called cells. Data transmitted from multiple sources is segmented into cells by the ATM network device, and the cells are then interleaved onto a single transmission media. It is asynchronous in the sense that the recurrence of cells depends upon the required or instantaneous bit rate. See also TDM and packet switching. Backbone The part of a network used as the primary path for transporting traffic between network segments. A high-speed line - or series of connections - that forms a major pathway within a network. Bandwidth The throughput, or ability to move information through or from a device, system or subsystem tem, usually measured in quantities of data per second. A measure of the information-carrying capacity of a communications channel; range of usable frequencies that can be carried by a system, corresponding to the difference between the lowest and highest frequency signal that can be carried by the channel. BLEC Building Local Exchange Carrier B-PON Broadband Passive Optical Network (PON) Broadcast One-to-all transmission where the source sends one copy of the message to all nodes, whether they wish to receive it or not.


21 of 57

CATV CATV (originally "community antenna television," now often "community access television") is more commonly known as "cable TV." In addition to bringing television programs to those millions of people throughout the world who are connected to a community antenna, cable TV is an increasingly popular way to interact with the World Wide Web and other new forms of multimedia information and entertainment services. Cell A unit of transmission in ATM. A fixed-size frame consisting of a 5-octet header and a 48-octet payload. Cell Delay Variation (CDV) CDV is a component of cell transfer delay, induced by buffering and cell scheduling. Peak-to-peak CDV is a QoS delay parameter associated with CBR and VBR services. The peak-to-peak CDV is the ((1-a) quintile of the CTD) minus the fixed CTD that could be experienced by any delivered cell on a connection during the entire connection holding time. The parameter a is the probability of a cell arriving late. CLEC (Competitive Local Exchange Carrier) In the United States, a CLEC (competitive local exchange carrier) is a company that competes with the already established local telephone business by providing its own network and switching. CO The Central Office is where communications common carriers terminate customer lines and locate switching equipment that interconnects those lines. Also, considered a location where Switching, Transmission and Power equipment that provide telephone service is centralized. Coaxial Cable A type of cable with a center conductor, an insulator, a solid or braided shield around this insulator with a tough jacket on the outside. The inner insulation provides a constant distance between the center conductor and the shielding, providing a superior quality signal over longer distances, which gives higher bandwidth and better immunity to external interference than simple twisted pair cable provides. Connection Admission Control (CAC) The set of actions taken by the network during the call setup phase (or during call renegotiation phase) in order to determine whether a connection request can be accepted or should be rejected (or whether a request for re-allocation can be accomplished). Constant Bit Rate (CBR) An ATM service category, which supports a constant or guaranteed rate to transport services such as video or voice as well as circuit emulation that requires rigorous timing control and performance parameters. QoS Parameter typically used for voice traffic. Core Network See backbone Coupler Fused fiber device that optically splits and multiplexes signals. The couplers used in the PON outside plant network are basically power splitter wherein the power from the OLT is sent into different branches of the network to feed the ONTs based upon their distance from the OLT. Another type of coupler/splitter is used to separate the incoming and outgoing signals into their respective wavelengths at the OLT and ONT. This is a WDM coupler/splitter and is sometimes referred to as an optical multiplexer/deplexer. CSMA/CA In computer networking, CSMA/CA belongs to a class of protocols called multiple access methods. CSMA/CA stands for: Carrier Sense Multiple Access With Collision Avoidance. In CSMA, a station wishing to transmit has to first listen to the channel for a predetermined amount of time so as to check for any activity on the channel. If the channel is sensed "idle" then the station is permitted to transmit. If the channel is sensed as "busy" the station has to defer its transmission. This is the essence of both CSMA/CA and CSMA/CD. In CSMA/CA (LocalTalk), once the channel is clear, a station sends a signal telling all other stations not to transmit, and then sends its packet. In Ethernet 802.11, the station continues to wait for a time, and checks to see if the channel is still free. If it is free, the station transmits, and waits for an acknowledgment signal that the packet was received.

CSMA/CA is a modification of pure Carrier Sense Multiple Access (CSMA). Collision avoidance is used to improve the performance of CSMA by attempting to be less "greedy" on the channel. If the channel is sensed busy before transmission then the transmission is deferred for a "random" interval. This reduces the probability of collisions on the channel.


22 of 57

CSMA/CA is used where CSMA/CD cannot be implemented due to the nature of the channel. CSMA/CA is used in 802.11 based wireless LANs. One of the problems of wireless LANs is that it is not possible to listen while sending, therefore collision detection is not possible. Another reason is the hidden terminal problem, whereby a node A, in range of the receiver R, is not in range of the sender S, and therefore cannot know that S is transmitting to R.

CSMA/CA can optionally be supplemented by the exchange of a Request to Send (RTS) packet sent by the sender S, and a Clear to Send (CTS) packet sent by the intended receiver R, alerting all nodes within range of the sender, the receiver, or both, to keep quiet for the duration of the main packet. This is known as the IEEE 802.11 RTS/CTS exchange.

CSMA/CD In computer networking, Carrier Sense Multiple Access With Collision Detection (CSMA/CD) is a network control protocol in which

a carrier sensing scheme is used. a transmitting data station that detects another signal while transmitting a frame, stops transmitting that frame,

transmits a jam signal, and then waits for a random time interval (known as "backoff delay" and determined using the truncated binary exponential backoff algorithm) before trying to send that frame again.

CSMA/CD is a modification of pure Carrier Sense Multiple Access (CSMA).

Collision detection is used to improve CSMA performance by terminating transmission as soon as a collision is detected, and reducing the probability of a second collision on retry.

Methods for collision detection are media dependent, but on an electrical bus such as Ethernet, collisions can be detected by comparing transmitted data with received data. If they differ, another transmitter is overlaying the first transmitter's signal (a collision), and transmission terminates immediately. A jam signal is sent which will cause all transmitters to back off by random intervals, reducing the probability of a collision when the first retry is attempted. CSMA/CD is a layer 2 protocol in the OSI model.

Ethernet is the classic CSMA/CD protocol. See also the similar Carrier sense multiple access with collision avoidance (CSMA/CA) protocol.

CWDM Coarse wavelength division multiplexing (CWDM) is a method of combining multiple signals on laser beams at various wavelengths for transmission along fiber optic cables, such that the number of channels is fewer than in dense wavelength division multiplexing (DWDM) but more than in standard wavelength division multiplexing (WDM).

CWDM systems have channels at wavelengths spaced 20 nanometers (nm) apart, compared with 0.4 nm spacing for DWDM. This allows the use of low-cost, uncooled lasers for CWDM. In a typical CWDM system, laser emissions occur on eight channels at eight defined wavelengths: 1610 nm, 1590 nm, 1570 nm, 1550 nm, 1530 nm, 1510 nm, 1490 nm, and 1470 nm. But up to 18 different channels are allowed, with wavelengths ranging down to 1270 nm.

The energy from the lasers in a CWDM system is spread out over a larger range of wavelengths than is the energy from the lasers in a DWDM system. The tolerance (extent of wavelength imprecision or variability) in a CWDM laser is up to 3 nm, whereas in a DWDM laser the tolerance is much tighter. Because of the use of lasers with lower precision, a CWDM system is less expensive and consumes less power than a DWDM system. However, the maximum realizable distance between nodes is smaller with CWDM

Cyclic Redundancy Check (CRC) A mathematical algorithm commonly implemented as a cyclic shift register that computes a check field for a block of data. The sender transmits this check field along with the data so that the receiver can either detect errors, and in some cases even correct errors. Dark Fiber Dark fiber refers to unused fiber-optic cable. Often times companies lay more lines than what's needed in order to curb costs of having to do it again and again. The dark strands can be leased to individuals or other companies who want to establish optical connections among their own locations. In this case, the fiber is neither controlled by nor connected to the phone company. Instead, the company or individual provides the necessary components to make it functional.


23 of 57

dBm Decibels in Milliwatts (dBm) Again, for the design engineer who is designing for the Passive Optical Network, the power out for most of the electronics is typically stated as decibels in Milliwatts, or dBm. Here, you see a table that is expressed in milliwatts of power, and the conversion to dBm. For most of us, when we talk about the optical power as in a system output power of 1 milliwatt, what we are saying is that the output power is 0 dBm. When we start calculating the link loss budget of a network in combination with the receiver specifications dictated by the active component providers we may think that if we increase the output power so the attenuation or loss is negated, then we can go unlimited distances with unlimited bandwidths. Because of some dispersion and scattering concepts, this is not so. Also in our link loss calculations, we will see when using the video overlay on the 1550 nanometer wavelength, the output power of the electronics will be stated as approximately 20 dBm or 100 milliwatts. 20 dBm of power is in the classification of lasers that can cause injury.

Table 1 Decibel Table Conversion: dBm = dB milliwatt = 10 x Log10 (Power in mW / 1 mW)

DLC Digital Loop Carrier DS0 Digital Signal level Zero: One 64 Kb channel DS1 Digital Signal level 1: 24 data channels (64 Kb) and 8 Kb for signaling; total data rate of 1.544 Mbps DS3 Digital Signal level 3: 28 DS1s encapsulated; 44.736 Mbps data rate. DSL Digital Subscriber Line is a method of providing high-speed data services over the twisted pair copper wires traditionally used to provide POTS. Types of DSL include ADSL (asymmetric digital subscriber line), HDSL (high data rate digital subscriber line), SDSL (single line digital subscriber line), and VDSL (very high data rate digital subscriber line). DSLAM Digital Subscriber Line Access Multiplexer Provides high-speed Internet or Intranet access over traditional twisted-pair telephone wiring through the use of ADSL technology. Provides simultaneous high-speed digital data access and POTS analog service over the same twisted-pair telephone line. Can be installed in the CO or at and ISP adjacent to the CO DWDM Dense Wave Division Multiplexing is an optical multiplexing technique used to increase the carrying capacity of a fiber network beyond what can currently be accomplished by time division multiplexing (TDM) techniques. Different wavelengths of light are used to transmit multiple streams of information along a single fiber with minimal interference.

Power Ratio dBm = 10 x Log10 (Power in mW / 1 mW) dBm 1 mW 1 mW/1mW=1 0 dBm = 10 x Log10 (1) 0dBm

2 mW 2 mW/1mW=2 3 dBm = 10 x Log10 (2) 3dBm



100mW 100 mW/1mW=100 20 dBm = 10 x Log10 (100) 20dBm

1 W 1000 mW/1mW=1000 30 dBm = 10 x Log10 (1000) 30dBm

10 W 10000mW/1mW=10000 40 dBm = 10 x Log10 (10000) 40dBm


24 of 57

Dense wavelength division multiplexing (DWDM) is a technology that puts data from different sources together on an optical fiber, with each signal carried at the same time on its own separate light wavelength. Using DWDM, up to 80 (and theoretically more) separate wavelengths or channels of data can be multiplexed into a lightstream transmitted on a single optical fiber. Each channel carries a time division multiplexed (TDM) signal. In a system with each channel carrying 2.5 Gbps (billion bits per second), up to 200 billion bits can be delivered a second by the optical fiber. DWDM is also sometimes called wave division multiplexing (WDM).

Since each channel is demultiplexed at the end of the transmission back into the original source, different data formats being transmitted at different data rates can be transmitted together. Specifically, Internet (IP) data, Synchronous Optical Network data (SONET), and asynchronous transfer mode (ATM) data can all be travelling at the same time within the optical fiber.

DWDM promises to solve the "fiber exhaust" problem and is expected to be the central technology in the all-optical networks of the future.

DWS DWS (Dynamic Wave Slicing) extends WDM (Wave Division Multiplexing) by "slicing" each wavelength so that it can serve multiple end points (customers). This provides a division of available bandwidth over a PON by enabling a single fiber segment to allocate bandwidth to multiple customers according to their particular needs (from 1.7 to 100 Mbps in 1.7 Mbps increments). This provides effective utilization of the total capacity of the fiber optic media. Easement An easement is the right to use another person's land for a stated purpose. It can involve a general or specific portion of the property. EPON Ethernet based Passive Optical Network (PON). (IEEE 802.3ah) Ratified in 2004, EPON is the standard of the Institute of Electrical and Electronics Engineers Inc. (IEEE). Running at 1.25 Gbps symmetric, it is highly suitable for data services. EPON uses IP rather than ATM data encapsulation. Erbium-Doped Fiber Amplifier (EDFA) A key enabling technology of DWDM, EDFAs allow the simultaneous amplification of multiple signals in the 15xx nanometer region, e.g. multiple 2.5 Gbps channels, in the optical domain. EDFAs drastically increase the spacing required between regenerators, which are costly network elements because they (1) require optical/electrical/optical conversion of a signal and (2) operate on a single digital signal, e.g. a single SONET or SDH optical signal. DWDM systems using EDFAs can increase regenerator spacing of transmissions to 500-800 km at 2.5 Gbps. EDFAs are far less expensive than regenerators and can typically be spaced 80-120 km apart at 2.5 Gbps , depending on the quality of the fiber plant and the design goals of the DWDM system. Ethernet A LAN used to connect devices within a single building or campus at speeds up to 10 Mbps. Within the OSI model, Ethernet is defined at layer one (physical) and layer two (data link). Based on Carrier Sense Multiple Access/Collision Detection (CSMA/CD), Ethernet works by simply checking the wire before sending data. Sometimes two stations send at precisely the same time in which case a collision is detected and retransmission is attempted. EFM (Ethernet in the First Mile or Ethernet over P2P) In the context of an optical access network, this term describes and architecture in which all optical links are from one point to another, without optical branching. However branching can be (and usually is) done at an intermediate point by way of an active device. The intermediate active device can be located anywhere in the network including the central office or a curb side enclosure. Fiber Access Terminal (FAT) A fiber optic access point sometimes referred to as a network access point (NAP). This may be in the form of an above ground pedestal, and aerial or buried splice closure. Fiber Distribution Hub/Terminal (FDH/FDT) A fiber optic distribution point sometimes referred to as a fiber service area interface (FSAI), service area interface (SAI), or local convergence point (LCP). This is an area where the primary optical feeder fibers and secondary optical distribution feeders are facilitated or combined.


25 of 57

Fiber Optic Cable A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves. Fiber optics has several advantages over traditional metal communications lines: Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data. Fiber optic cables are less susceptible than metal cables to interference. Fiber optic cables are much thinner and lighter than metal wires. Data can be transmitted digitally (the natural form for computer data) rather than analogically. Fibre Channel Fibre Channel is an industry standard technology for transmitting data between computer devices at up to 1.0625 Gbps and over 10 km in distance. Fibre Channel is optimized for connecting servers to shared storage devices and for interconnecting storage controllers and drives. Fibre Channel utilizes either an optical fiber or copper connection. FTTB Fiber to the Business/Basement FTTC Fiber to the Curb/Cabinet Fiber to the curb (FTTC) is a telecommunications system based on fiber-optic cables run to a platform that serves several customers. Each of these customers has a connection to this platform via coaxial cable or twisted pair.

Fiber to the curb allows delivery of broadband services such as high speed internet. High speed communications protocols such as broadband cable access (typically DOCSIS) or some form of DSL are used between the cabinet and the customers. The data rates vary according to the exact protocol used and according to how close the customer is to the cabinet.

FTTC is subtly distinct from FTTN or FTTP (all are versions of Fiber in the Loop). The chief difference is the placement of the cabinet. FTTC will be placed near the "curb" which differs from FTTN which is placed far from the customer and FTTP which is placed right at the serving location.

Unlike the competing fiber to the premises (FTTP) technology, fiber to the curb can use the existing coaxial or twisted pair infrastructure to provide last mile service. For this reason, fiber to the curb costs less to deploy. However, it also has lower bandwidth potential than fiber to the premises.

In the United States of America, the largest deployment of FTTC was carried out by BellSouth Telecommunications. With the acquisition of BellSouth by AT&T, deployment of FTTC will end. Future deployments will be based on either FTTN or FTTP. Existing FTTC plant may be removed and replaced with FTTP.[5]

FTTN Fiber to the Node (FTTN), also called fiber to the neighborhood or fiber to the cabinet (FTTCab),[3] is a telecommunication architecture based on fiber-optic cables run to a cabinet serving a neighborhood. Customers connect to this cabinet using traditional coaxial cable or twisted pair wiring. The area served by the cabinet is usually less than 1,500 m in radius and can contain several hundred customers. (If the cabinet serves an area of less than 300 m in radius then the architecture is typically called fiber to the curb.)[4]

Fiber to the node allows delivery of broadband services such as high speed internet. High speed communications protocols such as broadband cable access (typically DOCSIS) or some form of DSL are used between the cabinet and the customers. The data rates vary according to the exact protocol used and according to how close the customer is to the cabinet.

Unlike the competing fiber to the premises (FTTP) technology, fiber to the node can use the existing coaxial or twisted pair infrastructure to provide last mile service. For this reason, fiber to the node costs less to deploy. However, it also has lower bandwidth potential than fiber to the premises. FTTX Fiber to the "x" c/b/h/k FSAN Full Service Access Network. is a forum for the worlds leading telecommunications services providers and equipment suppliers to work towards a common goal of truly broadband access networks. For more information visit http://www.fsanet.net


26 of 57

Gigabit Ethernet Another variation of the Ethernet protocol, is capable of transmitting data at one billion bits per second. This standard may eventually challenge ATM and Frame Relay as the high-speed LAN topology of choice, but, at present, ATM and Frame Relay still offer Quality of Service (QoS) guarantees that Gigabit Ethernet cannot match. Gigabit Ethernet can use high-quality copper wire at distances of less than 25 meters and optical fiber cabling for greater distances. GEPON Giga-Bit Ethernet Passive Optical Network (See EPON) Headend MSO (CATV) telecommunications office Header Error Control (HEC) A 1-octet field in the ATM cell header containing a CRC checksum on the cell header fields, HEC is capable of detecting multiple bit errors or correcting single bit errors. HDSL Unlike ADSL, High Bit Rate Digital Subscriber Line (HDSL) is a symmetric method of transmitting data at rates up to 1.5 Mbps in both directions. Because of the symmetric properties, the highest transmission rates can only be supported at lengths of 15,000-foot distances of two or more twisted pair lines. HPNA Home Phone Networking Alliance seeks to establish standards for home networking over regular coax and phone lines within the home - for compatibility between telecom, computer and network products. HomePNA is a relatively new technology, which allows you to network your home computers much like a LAN using your existing telephone wiring. Internet access can be shared among several computers with or without a router. Computers can access each others peripherals like printers and storage devices as well as the ability to play multiplayer games. HomePNA uses frequencies different from voice or fax calls while conducting data across the phone line.

Coaxial cables are included in the HomePNA 3.1 standard to increase the networking capabilities and overcome some limitations of phone jack location. It's not clear if this part of HomePNA 3.1 specification will be included in ITU G.9954 (01/07) or in any specification another standard body or will remain available only to HomePNA members.

ICP Integrated Communications Provider (e.g. ATG) Internet Protocol (IP) A set of rules for how data gets transmitted from one place to another on the Internet. IP is a connectionless protocol, in which data gets broken down into a number of small bundles known as packets, and each packet gets transmitted to the destination separately, possibly along a different route than other packets from the same message. IOT Intelligent Optical Terminal ISP Internet Service Provider ITU International Telecommunications Union IAD Integrated Access Device Lambda (l) Greek symbol used to signify wavelength. Last Mile The last mile is the local access network that extends from the Central Office (CO) to the end-user subscriber. Also called the local loop network, it is traditionally copper-based and suffers from the bandwidth limitations of that media. Leased Line A physical line that a single subscriber leases from a carrier, giving the subscriber exclusive rights to the line's capacity.


27 of 57

Line (SONET) A transmission medium, together with the associated Line Terminating Equipment (LTE), required to provide the means of transporting information between two consecutive line terminating network elements, one of which originates the line signal and the other terminates the line signal. Multimedia over Coax Alliance The Multimedia over Coax Alliance (MoCA) is an open, industry driven initiative promoting distribution of digital video and entertainment through existing coaxial cable in the home. MoCA technology provides the backbone for whole home entertainment networks of multiple wired and wireless products. The goal of the Multimedia over Coax Alliance is to facilitate home networking on existing coaxial cable in the 1 GHz microwave band. This cable can be used for data connections to televisions, set top boxes, and other entertainment devices without the need for new connections. The technology underlying MoCA provides the elements necessary to use this cable to distribute high-quality multimedia content and high-speed data with throughput exceeding 100 Mbit/s. MoCA is a non-profit mutual benefit corporation to develop and promote specifications for the transport of digital entertainment and information content over coaxial cable. MoCA members have agreed as part of membership to license under reasonable and non discriminatory (RAND) terms any intellectual property required for member companies to implement the MoCA Specification. Metro Network A network spanning a geographical area greater than a LAN but less than a WAN (Wide Area Network). IEEE 802.6 specifies the protocols and cabling for a MAN. MTU/MDU Multiple Tenant Unit/Multiple Dwelling Unit - a building with more than one residence or business. MSO Multiple Systems Operator (i.e., CATV company) Multi-mode Fiber Optical fiber supporting propagation of multiple modes of light. Multimode fibers have a larger core diameter than single mode fibers. Multi-Cast The ability of one network node to send identical data to a number of end-points. (Usually associated with multicast video techniques where the source will send a single stream and multiple end-points will accept the stream.) Transmission of information to a group of recipients via a single transmission by the source, in contrast to unicast or broadcast. In IP multicast, there is a one-to-many transmission, where a host may join or leave a group at any time. Multiplex A general concept that refers to combining independent sources of information into a form that can be transmitted over a single communication channel. Multiplexing can occur both in hardware (i.e., electrical signals can be multiplexed) and in software (i.e., protocol software can accept messages sent by multiple application programs and send them over a single network to different destinations). NGDLC Next Generation Digital Loop Carrier OAN Optical Access Networking OAS Optical Access Switch OC-# Short for Optical Carrier, used to specify the speed of fiber optic networks conforming to the SONET standard. The table shows the speeds for common OC levels.

OC-1 = 51.85 Mbps OC-3 = 155.52 Mbps OC-12 = 622.08 Mbps OC-24 = 1.244 Gbps OC-48 = 2.488 Gbps OC-192 = 9.952 Gbps OC-768 = 39.808 Gbps


28 of 57

ODN The Optical Distribution Network is the optical fiber access network usually used to describe the PON Network, the outside plant (OSP). The ODN consists of but is not limited to the optical fiber, optical distribution cabinets, splitters, and optical access points. ODSI Optical Domain Service Interconnect is an open, informal initiative comprised of service providers and networking vendors. ODSI represents a coalition of networking professionals with a common interest in selecting, applying and promoting the open interfaces and protocols that will allow higher-layer service networks to effectively interoperate with the intelligent optical network core. http://www.odsi-coalition.com. Open Systems Interconnection (OSI) A logical structure for network operations standardized by the International Standards Organization (ISO). The OSI model organizes the communications process into seven different categories and places the categories in a layered sequence based on their relationship to other users. Layers, seven through four, deal with end-to-end communications between the message source and the message destination, while layers three through one deal with network access. OLT The optical line termination is the PON controller card or unit located at the CO. The terminal at the subscribers end of the network is the ONT or optical network terminal. Several OLTs may be located in a single chassis. The laser at the OLT is frequently a DFB (distributed-feedback laser) transmitting at 1490nm and is always on. Signals from the OLT tell the ONTs when to send upstream traffic to it. ONT The optical network termination resides at the subscribers end of the PON. It provides the interface between the network and the subscribers equipment. Frequently the laser used at the ONT is a Fabry Perot type and operates at 1310nm and only transmits when given permission by the OLT. Operations Administration and Maintenance (OAM) A group of network management functions that provide network fault indications, performance information and data and diagnosis functions. OSP Outside Plant (See ODN) Path (SONET) A path at a given bit rate is a logical connection between the point at which a standard frame format for the signal is assembled, and the point at which the standard frame format for the signal is disassembled. Payload The data in an ATM cell or IP packets that subscribers want to access (the message, conversation, file, etc.). The term payload is used to distinguish the subscriber's data from the "overhead," which is data in an ATM cell or IP packet that network equipment tacks on to the payload to help guide its transmission across the network. PBX Private Branch Exchange PON A Passive Optical Network (PON) is made up of fiber optic cabling and passive splitters and couplers that distribute an optical signal through a branched "tree" topology to connectors that terminate each fiber segment. Compared to other access technologies, PON eliminates much of the installation, maintenance, and management expenses needed to connect to customer premises. Per the FSAN specifications PON is a point to multipoint system with one OLT at the central office servicing up to 32 ONTs. The system is single fiber with downstream traffic sent in the 1550 nm wavelength window and upstream traffic being sent in the 1310 wavelength window. This is an example of Bi-directional transmission on a single fiber. Sometimes the PON is called B-PON, which indicates it is a Broadband PON. Also it can be an APON, which is an ATM based PON or an EPON, which is an Ethernet based PON. Point of Presence (POP) A facility used by a network access provider to house physical equipment that enables subscribers to access the network. The term is used to describe the location where a long distance carrier connects to a local service carrier, and also the location where an Internet service provider houses equipment that enables dialup subscribers to access the Internet.


29 of 57

Public Switched Telephone Network (PSTN) The traditional voice network infrastructure, including both local service and long distance service that has been in use in various parts of the world for up to a century or so. Quality of service (QoS) The concept of applying and ensuring specific, quantifiable performance levels on a shared network. Performance can be assessed based on physical measurements of the network, the methods by which network traffic is prioritized, and on how the network is managed. Regional Bell Operating Company (RBOC) One of six telephone companies created after AT&T divestiture. Also, the acronym for the local telephone companies created in 1984 as part of the break-up of AT&T. (The six RBOCs are Ameritech, Bell Atlantic, Bell South, NYNEX, Southwestern Bell and U.S.West. Some of the six have and/or are merging.)

Right-of-Way - A right-of-way is a type of easement that gives someone the right to travel across property owned by another person.

Router A computer that directs bundles of data being transmitted between nodes on different networks. RT Remote Terminal Scalable The ability to add power and capability to an existing system without significant expense or overhead. Simple Network Management Protocol (SNMP) A set of protocols for managing complex networks. SNMP works by sending messages, called protocol data units (PDUs), to different parts of a network. SNMP compliant devices called agents, store data about themselves in Management Information Bases (MIBs) and return this data to the SNMP requesters. Single Mode Fiber Used to describe optical fiber that allows only one mode of light signal transmission SONET Synchronous Optical Network Standards for transmitting digital information over optical networks. It defines a physical interface, optical line rates known as Optical Carrier (OC) signals, frame formats and a OAM&P (Operations, Administration, Maintenance and Provisioning) protocol. The base rate is known as OC-1 and runs at 51.84 Mbps. Higher rates are a multiple of this such that OC-12 is equal to 622 Mbps (12 times 51.84 Mbps) STS-1 Synchronous Transport Signal 1 - Electrical SONET signal at 51.84 Mbps. T1 Refers to a networking standard capable of transmitting data at a rate of 1.54-Mbps. This protocol is commonly employed by very large enterprises such as telecommunications companies, the Internet backbone and connections from Internet service providers to the Internet backbone T3 A faster implementation of T1. Using coaxial cable, T3 allows for data transmission rates of 45 Mbps and is used for WAN backbones , the Internet backbone and connections from Internet service providers to the Internet backbone. TDM Time Division Multiplex - A method for transmitting multiple calls over a single line; each call is assigned a recurring timeslot on the line, and a small portion of that call gets transmitted over the line each time its assigned timeslot is available. TDMA Time Division Multiple Access


30 of 57

Twisted pair cable A form of wiring in which a pair of wires are wrapped around one another again and again. Twisting two wires reduces their susceptibility to electrical interference. UBR Unspecified Bit Rate - a QoS parameter used typically used for data transmission. Unicast The transmit operation of a single PDU (protocol data unit) from one source to a single destination. In Unicast video, this is one channel delivered to a single interface device. Point-to-point transmission requiring the source to send an individual copy of a message to each requester. (See multicast.) Variable Bit Rate (VBR) An ATM Forum defined service category which supports variable bit rate data traffic with average and peak traffic parameters. A generic term for sources that transmit data intermittently. The ATM Forum divides VBR into real-time and non-real-time service categories in terms of support for constrained Cell Delay Variation (CDV) and Cell Transfer Delay (CTD). Vault Outside plant enclosure used to house telecommunications equipment. VDSL or VHDSL (Very High Bitrate DSL)[1] is a DSL technology providing faster data transmission over a single twisted pair of copper wires. VDSL is a scheme to boost transmission speeds to as much as 52 Mbps for very short distances (up to 1000 ft.) on copper wire, or longer distances in fiber-optic networks.

These fast speeds mean that VDSL is capable of supporting high bandwidth applications such as HDTV, as well as telephone services (Voice over IP) and general Internet access, over a single connection. VDSL is deployed over existing wiring used for POTS (Plain Old Telephone System) and lower-speed DSL connections.

Second-generation VDSL2 systems (ITU-T G.993.2) utilize bandwidth of up to 30 MHz to provide data rates exceeding 100 Mbit/s simultaneously in both the upstream and do

Date post:	09-Oct-2015
Category:	Documents
Upload:	tran-quang-anh
View:	53 times
Download:	2 times

PON Design

Documents