# Presentation: 657319

## National Communications System (NCS)Local Loop Overview

**Ralph U. Silver**
**BellSouth Network Training**
**BellSouth Telecommunications**
**ralph.silver@bellsouth.com **
**404-927-5750**** **

## Presentation Contents

**Presentation Contents**
- Telecom Plant Basics
- Copper Distribution
- Feeder-Distribution Interfaces
- Electronic Equipment in the Local Loop
- SONET Multiplexers
- Digital Loop Carrier: Copper T-1 Feed
- Digital Loop Carrier: SONET Mux Feed
- DSL Access Multiplexer
- Fiber to the Curb
- Fiber to the Home/Premises
- Wireless Options: Cellular
- Wireless Options: WiMAX
- Wireless Options: WiFi
- Catastrophic Events & the Local Loop
- Recovery Efforts
- References & Glossary

## I. Telecom Plant Basics

**I. Telecom Plant Basics**

## Main Components of a Telecom Network

**Main Components of a Telecom Network**
- Outside Plant (OSP) – buried and aerial cables, poles, manholes, and other structures and in customer premises.
- Central Office (CO) – a building equipped with switches, routers and many other devices to support the outside plant and to connect to other central offices.
- Inter-Office Facilities (IOF) – equipment and cables used to interconnect central offices.

## The Basic Telephone Circuit

**The Basic Telephone Circuit**

**(Twisted Pair)**

## Twisted Pairs

**Twisted Pairs**
- A pair of copper conductors that are used to transmit electrical signals. They are twisted around each other to cancel electromagnetic interference that causes cross-talk.
- In telecommunications, the unshielded twisted pair (UTP) is commonly used to transmit telephony and data in analog and in digital forms.
- We use the word *pairs* to indicate the plural of twisted pair.

## Twisted Pairs (continued)

**Twisted Pairs** (continued)
- The conductor pairs must be insulated from each other. In the last 35+ years, the insulation has been plastic, and each pair has been color coded to identify it from others.

## Twisted Pairs (continued)

**Twisted Pairs** (continued)
- Many older cables, however, have paper-like insulation that is known as *pulp insulation*.
- Pulp-insulated conductors are very susceptible to damage from water, so when placed in underground conduits, they are kept dry via pressurized air.

## Applications of Twisted Pairs

**Applications of Twisted Pairs**
- The electric signals transmitted on twisted pairs can be analog or digital. The following are the most common applications of twisted pairs in telecommunications.
*POTS*
- Plain Old Telephone Service (POTS), requires one twisted pair per telephone line.
- The POTS signals are analog, which means that the electric flow is continuous, even as the voltage and amperage vary.

## Applications of Twisted Pair (continued)

**Applications of Twisted Pair (continued)**
*T-1*
- A set of two twisted pairs can also be conditioned to transmit a 1.5Mbps digital signal called a DS1.
- Such lines are known as T-1 lines.
- T-1 lines can transport 24 digitized POTS lines in 64Kbps digital signals called DS0 (D-S-zero).

## Applications of Twisted Pair (continued)

**Applications of Twisted Pair** (continued)
*ISDN*
- Twisted pairs are also used to transmit *Integrated Services Digital Network* (ISDN) in two forms:
*Basic Rate Interface* (BRI) provides a 128Kbps digital signal _with __**2**__ __*bearer*_ channels for information and 1 *data* channel for overhead (known as 2B+D)
*Primary Rate Interface* (PRI) provides a 1.5Mbps digital signal with 23 bearer channels for information and one data channel for overhead (known as 23B+D)

## Applications of Twisted Pair (continued)

**Applications of Twisted Pair** (continued)
*DSL*
- Twisted pairs can be used to provide *Digital Subscriber Line* (DSL) service. DSL uses discrete multi-tone modulation (DMT) to generate a digital signal.
- DSL can be provided in many different downstream line rates, ranging from to 256Kbps to 24Mbps.
- Upstream rates range from 128Kbps to 1.5Mbps.

## Applications of Twisted Pair (continued)

**Applications of Twisted Pair** (continued)
*Power*
- Twisted pairs can also be used to provide electric power to remote equipment.
- This is done in *fiber-to-the-curb* (FTTC) architectures, which will be discussed later.

## Fiber

**Fiber**
- Fiber optics consists of strands made of highly pure glass.
- The purity of the glass and the consistency of the geometry of the fiber strand, allow light to be transmitted through it for long distances.
- These characteristics make fiber optic strands an ideal method for transmitting data at very high rates.

## Cable

**Cable**
- Multiple twisted copper pairs are wrapped into bundles known as *binder groups,* and the binder groups are encased in tubular sheathing. This is known as cable.
- Binder groups in most modern cables are made up of 25 twisted pairs.
- A twisted pair cable may contain from 1 to 168 binders, for a total of 25 to 4200 pairs (i.e., 25 pairs per binder).

## Cable (continued)

**Cable** (continued)
- The tubular exterior of cable is known as the *cable sheath*. The sheath in modern cables is made of a rugged, highly durable plastic.
- Some very old cables have sheaths that are made of lead, and they require special handling due to the toxicity of lead.

## Cable (continued)

**Cable** (continued)
- The picture below shows a cable with its twisted pairs exposed.

## Cable (continued)

**Cable** (continued)
- A cable may also contain fiber optic strands instead of twisted pairs.
*Fiber cable*, as it is known, is mostly used in high capacity transport.

## Cable (continued)

**1**

**Cable** (continued)
- The cable below shows a fiber sheath containing loose-tube fibers.

## Cable (continued)

**Cable** (continued)
- Fiber cables also have multiple bundles of fibers. Fiber bundles contain 12 fibers per binder group.
- Fiber cables can contain from 2 to 864 fibers.
- In recent years, fiber cable has also been used to serve individual customers in what is known as fiber-to-the-premises (FTTP), fiber-to-the-home (FTTH), and fiber-to-the-curb (FTTC) architectures.
- These will be explained later.

## Cable Specs

**Cable Specs**
- There are many types of cable specifications from which to choose.
- The selection is determined by:
- the signal transmission requirements
- the required capacity
- the environment in which the cable is to be installed

## A) Transmission Requirements

- The signal transmission requirements will determine:
- the American Wire Gauge (AWG) of the conductors (electrical signal)
- 19 gauge
- 22 gauge
- the design of the sheath
- the selection of shielding within the sheath
- the type of fiber used (optical signal)
- multi-mode fiber
- single-mode fiber

- 24 gauge
- 26 gauge

## B) Capacity

*B) Capacity*
- The capacity requirement will determine the size of the cable in terms of the number of pairs or fibers that are required.
- Size ranges include:
- Twisted pairs: 25 to 4200 pairs
- Fibers: 2 to 864 fibers

## C) Environment

*C) Environment*
- Cable is installed in many environments:
- In earth – known as *buried cable*; requires a special cable that has a gel filler to eliminate air gaps and thus prevent water intrusion.
- On pole lines – known as *aerial cable;* has an air core to reduce weight; the sheath can be hardened and provided with steel armor to protect it from squirrels.

## C) Environment (continued)

*C) Environment* (continued)
- In conduit runs with manholes – known as *underground cable*; gel-filled cable is used in modern installations
- Under water – known as *submarine cable*; requires a gel-filled interior and a special, extra rugged sheath design that includes layers of steel armor.

## II. Copper Distribution

**II. Copper Distribution**

## Customer Premises

**Network Interface Device (NID):** Demarcation point between inside wiring and TELCO facilities. Serves as testing point to isolate problems in the circuit.

**Inside Wiring:**
- Belongs to the house
- Distributes telephony and DSL service throughout the structure
- Uses unshielded twisted copper pairs

**Telephone Wiring Jack:**
- Belongs to the house
- Connected to the inside wiring
- RJ11 connector is standard

**Customer Premises**

## RJ11 Wall Jack

**RJ11 Wall Jack**

**RJ11 Connector**

**Network Interface Device**

**Customer Premises**

## Direct Feeder Architecture

**Distribution Terminal:**
- Used to access individual pairs in the cable and connect them to the subscriber’s service wire. Can be pole mounted for aerial cable, or pedestal mounted for buried cable.

**NID**

**Service Wire:**
- Connects the subscriber’s NID to a distribution terminal. Can be aerial or buried. Also known as a drop wire. Come in 1, 2, or 5-pair capacity.

**Feeder Cable:**
- Provides connectivity between the central office and the outside facilities. Referred to as Facilities 1 (F1).
- Depending on the type used, they may contain 25 - 2000 copper pairs, & may have plastic or pulp insulated conductors, and gel or air fill.

**Central Office (CO):**
- A building that houses electronic equipment such as switches and routers. The CO is at the center of the local network and it provides connections to the rest of the networks in the world.

**Direct Feeder Architecture**

## Direct Feeder Architecture

**Direct Feeder Architecture**

**Service Wire**

**Aerial Service Wire connected**
**To a NID**

## Direct Feeder Architecture

**Direct Feeder Architecture**

**Aerial Terminal**

**Pedestal Terminal**

## Direct Feeder Architecture

**Direct Feeder Architecture**

**Twisted Pair Cable**

## Direct Feeder Architecture

**Direct Feeder Architecture**

**Central Office (CO)**

## III. Feeder-Distribution Interfaces:

**III. Feeder-Distribution Interfaces:**
**Distributed Feeder Architecture**

## Feeder-Distribution Interface (FDI)

**Feeder-Distribution Interface (FDI)**
- FDIs provide an important function in the local loop. They serve as the interface between cables coming from the central office and cables distributed to customers.
- They also provide a useful location from which to test circuits and isolate problems in the line.
- Other names for FDI include: cross-connect box, cross-box, serving area interface (SAI).

## Feeder-Distribution Interface (FDI) (continued)

**Feeder-Distribution Interface (FDI) (continued)**
- When an FDI is installed, the cable plant is segmented into two major components known as:
- Feeder facilities (F1)
- Distribution facilities (F2)

## Distributed Feeder Architecture: Copper-Fed FDI

**App Servers**

**Distribution**
**Terminal**

**Central Office (CO)**

**Feeder cable/F1**

**NID**

**Feeder-Distribution Interface (FDI):**
- Used to administer distribution cable pairs and connect them to feeder cable. Serves as testing point to isolate problems in the circuit. Also known as a cross-connect box, cross-box, serving area interface (SAI), or interface.

**Distribution Cable:**
- Used to administer distribution cable pairs and connect them to feeder cable. Separating feeder from distribution allows greater flexibility and reduced costs in equipping a central office.  Also known as Facilities 2 (F2).

**Distributed Feeder Architecture: Copper-Fed FDI**

**Service **
**Wire**

## Distributed Feeder Architecture: Copper-Fed FDI

**Distributed Feeder Architecture: Copper-Fed FDI**

- Feeder-Distribution Interface (FDI)

- Open View

- Closed View

## Distributed Feeder Architecture: Copper-Fed FDI

**Distributed Feeder Architecture: Copper-Fed FDI**

- Feeder-Distribution Interface (FDI)

- Close-up View of Binding Posts

## IV. Electronic Equipment in the

**IV. Electronic Equipment in the**
**Local Loop**

## Electronic Equipment in the Local Loop

**Electronic Equipment in the Local Loop**
- Electronic equipment in the local loop is vital in providing today’s high-bandwidth services. _They_ fall into the following categories.
- SONET Multiplexers
- Digital Loop Carrier
- DSL Access Multiplexers
- Fiber to the Curb

## V. SONET Multiplexers

**V. SONET Multiplexers**

## SONET Multiplexers

**SONET Multiplexers**
- The importance of SONET multiplexers cannot be overstated. They tie together every major network element in a modern telecommunications network.
- Synchronous Optical NETwork (SONET), is a technology that enables optical transport of high-bandwidth signals over long distances.
- Telecom companies build SONET networks in ring topologies to create what is known as a self-healing ring (SHR).

## SONET Multiplexers (continued)

**SONET Multiplexers (continued)**
- The equipment nodes in these rings serve to take optical signals down to an electrical level to feed other equipment to provide customer service.
- Besides POTS and voice communications, a significant part of these networks is used to interconnect enterprise LANs (Local Area Networks).
- In fact, LAN interconnection services are the fastest growing driver of new telecommunications technologies.

## SONET Multiplexers (continued)

- Example of a SONET multiplexer equipped to deliver 28 T-1s and one T-3.
- This model can transport up to 622Mbps of data and voice traffic over a SONET ring.

**SONET Multiplexers (continued)**

## SONET Multiplexers (continued)

- This next-generation multiplexer can deliver even more T-1s and T-3s for service. This model can transport up to 2.488Gbps of data and voice traffic.

**SONET Multiplexers (continued)**

## SONET Multiplexers (continued)

- Illustration of a 4-node SONET ring.
- A multiplexer is generally referred to as a MUX.

**SONET Multiplexers (continued)**

**MUX**

**Fiber**
**Cable**

## SONET Multiplexers (continued)

**SONET Multiplexers (continued)**
- All of the subsequent electronic network elements that are presented here are supported by SONET multiplexers.
- The only exception is T-1 fed Digital Loop Carrier, which is explained next.

## VI. Digital Loop Carrier (DLC):

**VI. Digital Loop Carrier (DLC):**
**Copper T-1 Feed**

## Digital Loop Carrier: Copper T-1 Feed

**App Servers**

**Distribution**
**Terminal**

**Distribution cable/F2**

**FDI**

**Central Office (CO)**

**Feeder cable**
**/F1**

**DLC**

**Digital Loop Carrier (DLC):**
- Performs A/D and D/A conversion of POTS
- Takes channels from the DS1 signal and converts them to DS0s for POTS
- DS1 signals can be received from a T-1 or from a fiber multiplexer
- Needs commercial power and has battery back-up
- Usually installed in private easements or inside buildings
- Installed in a cabinet, vault, hut, or building to protect the electronics

**NID**

**T-1 Lines (digital):**
- Use twisted pair cable
- Line-powered from the CO
- Provide channelized DS1 signals to the DLC
- Require signal regeneration approximately every 6000’.
- Each T-1 transports one DS1 signal

**Service **
**Wire**

**Digital Loop Carrier: Copper T-1 Feed**

## DLC cabinet with door open

**Digital Loop Carrier: Copper T-1 Feed**

**Cabinet Enclosures**

## Digital Loop Carrier: Copper T-1 Feed

**DLC in electronics hut**

**DLC in Controlled Environment **
**Vault (CEV)**

**Digital Loop Carrier: Copper T-1 Feed**

**Other Enclosures**

## VII. Digital Loop Carrier:

**VII. Digital Loop Carrier:**
**SONET Mux Feed**

## Digital Loop Carrier: Fiber Mux Feed

**App Servers**

**Distribution**
**Terminal**

**Distribution cable/F2**

**Central Office (CO)**

**Feeder cable**
**/F1**

**DLC**

**NID**

**SONET Multiplexer:**
- Receives optical signals carrying channelized DS1s from the CO and converts each DS1 to a T-1 to feed the DLC equipment
- Can also receive optical signals carrying DS3s for service or for DSL Access Multiplexers
- Frequently referred to as a MUX

**Fiber Cable:**
- Optically transports signals from the CO to multiplexers in DLC sites.

**T-1**

**Service **
**Wire**

**FDI**

**Digital Loop Carrier: Fiber Mux Feed**

## Fiber cable sheath with ribbons of fibers to connect the fiber multiplexer to the central office

- Fiber cable sheath with _ribbons of_ fibers to connect the fiber multiplexer to the central office

**Digital Loop Carrier: Fiber Mux Feed**

- Cross-sectional view of one ribbon of fibers

## VIII. DSL Access Multiplexer (DSLAM)

**VIII. DSL Access Multiplexer (DSLAM)**

## DSL Access Multiplexer (DSLAM)

**Distribution**
**Terminal**

**Service **
**Wire**

**Distribution cable/F2**

**Central Office (CO)**

**Feeder cable**
**/F1**

**DLC**

**T-1**

**MUX**

**Fiber **
**Cable**

**FDI**

**DSL Access Multiplexer (DSLAM):**
- Receives electrical DS3 from the CO via a multiplexer
- Takes Feeder pairs from FDI and adds DSL channels to them
- Referred to as a DSLAM

**DS3**

**DSL Access Multiplexer (DSLAM)**

## DSLAM mounted on a rack

**DSL Access Multiplexer (DSLAM)**

## IX. Fiber to the Curb (FTTC)

**IX. Fiber to the Curb (FTTC)**

## Fiber-to-the-Curb (FTTC)

**Fiber-to-the-Curb (FTTC)**
- FTTC is a new architecture that has been deployed for the last several years.
- It consists of placing fiber cables in neighborhoods and businesses and connecting electronics equipment at the edge of the customer premises.
- FTTC also requires specialized DLC equipment that can support optical transmission of POTS lines.

## Fiber-to-the-Curb (FTTC) (continued)

**Fiber-to-the-Curb (FTTC) (continued)**
- FTTC allows optimal quality of services and it enables higher-bandwidth services to be provided.
- The term FTTC stems from the fact that when deployed in neighborhoods, the electronics terminal -known as an optical network _unit_ (ONU)- sits near the street curb.
- This is a different architecture from fiber-to-the-premises (FTTP), to be explained later in this presentation.

## Fiber To The Curb

**ONU**

**Service **
**Wire**

**Distribution Fiber with Twisted Pairs for Power**

**Central Office (CO)**

**DLC**

**T-1**

**MUX**

**Fiber **
**Cable**

**Optical Network Unit (ONU):**
- Consists of a metallic, weatherproof enclosure equipped with electronics
- Distribution fiber cable is looped into the enclosure and one fiber strand is connected to the optical line interface
- ONUs remain on the edge of the street, thus the term fiber-to-the-curb

**Fiber To The Curb**

**DS3 for DSL**

**NID**

**Distribution Fiber:**
- FTTC requires placing fiber as distribution cable
- Twisted copper pairs must be included alongside or within the fiber cable sheath to provide electrical power to the ONUs

## Optical Network Unit (ONU)

**Fiber To The Curb**

## DLC cabinet for FTTC

**Fiber To The Curb**

## X. Fiber to the Premises (FTTP) & 

**X. Fiber to the Premises (FTTP) & **
**Fiber to the Home (FTTH)**

## Fiber-to-the-Premises (FTTP)

**Fiber-to-the-Premises (FTTP)**
- FTTP is another new architecture that has been deployed for the last few years.
- It consists of placing fiber cables in neighborhoods and businesses and connecting electronics equipment at the edge of the customer premises.
- It differs from FTTC in that the electronics terminal resides inside the customer’s premises.

## Fiber-to-the-Premises (FTTP) (continued)

**Fiber-to-the-Premises (FTTP) (continued)**
- Placing the electronics terminal inside the customer’s premises relies on the customer’s power feed to the electronics.
- For this reason, a rechargeable battery backup unit connected to an AC outlet needs to be installed inside the customer premises.

## XI. Wireless Options:

**XI. Wireless Options:**
**Cellular Systems**

## Cellular Systems

**Cellular Systems**
- Cellular systems are an efficient and popular telecommunications technology.
- The convenience of a cellular telephone has overridden the lowered sound quality and connection reliability.
- There are several cellular technologies that have been deployed in the U.S. alone.

## Cellular Systems (continued)

**Cellular Systems (continued)**
- The latest cellular system technologies deployed in the U.S. include:
*CDMA - *Code Division Multiple Access
*GSM - *Global System for Mobile
- GPRS & EDGE are subsets of GSM
*iDEN* - Integrated Digital Enhanced Network
*UMTS - *Universal Mobile Telecommunications System
- CDMA2000 is a subset of UMTS

## Cellular Systems (continued)

**Cellular Systems (continued)**
- Regardless of the wireless technology used by the carrier, the physical architectures remain relatively the same.
- A cellular system consists of:
- Antenna arrays
- Base Transceiver Stations (BTS)
- Mobile Telephone Switching Office (MTSO)
- Backhaul connectivity
- Commercial power source

## Cellular Systems (continued)

**Cellular Systems (continued)**

**PSTN**

- MTSO

- DS1 or DS3
- wireline connection

**Cell Site:**
- Includes antenna array & Base Transceiver Station

**Cell System:**
- Several coordinated cell sites are known as a cell system. Each cell covers an area with a radius ranging from 1-20 miles

**Cellular Backhaul:**
- Consists of DS1 or DS3 wireline trunks. These wireline trunks are usually transported via DLC and multiplexers. Some networks may use microwave transmission for backhaul.

**MTSO:**
- Each cellular switching station controls the operation of a cellular system.

## Cellular Systems (continued)

**Cellular Systems (continued)**
- Main take-away: Even though the connection from the phone set to the antenna is wireless...
- ... the antenna’s connection back to a switch is usually carried by wireline telecom equipment...
- 		...and commercial power is still needed.

## Cellular Tower Connections

**Central Office (CO)**

**MUX**

**Fiber **
**Cable**

**T-1 or T-3 from co-located telecom multiplexer**

**Cellular Tower Connections**

**BTS**

**Fiber **
**Cable**

**MUX**

**Base Transceiver Station inside electronics hut**

**MTSO**

**Mobile Telephone Switching Office**

## XII. Wireless Options:

**XII. Wireless Options:**
**WiMAX**

## WiMAX

**WiMAX**
- Worldwide Interoperability for Microwave Access (WiMAX) is a technology that enables wireless transmission of digital broadband signals.
- Effectively, it is supposed to be a replacement for wireline DSL and cable modem.
- It may also be used for wireless backhaul.

## WiMAX (continued)

**WiMAX (continued)**
- Two forms of WiMAX are being developed:
- Fixed WiMAX – standard IEEE 802.16d
- Mobile WiMAX – standard IEEE 802.16e
- Most immediate practical applications for WiMAX are:
- backhauling traffic from cellular and WiFi base stations to a central office
- replacement of enterprise T-1 circuits
- alternative to DSL and cable modem in rural or developing regions

## WiMAX (continued)

**WiMAX (continued)**

**Central Office (CO)**

**MUX**

**Fiber **
**Cable**

**T-1 or T-3 from co-located multiplexer**

**BTS**

**Base Transceiver Station inside electronics cabinet**

**WiMAX**
**Antenna**

**PC**

**Modem**

**Non-line-of-sight**
**signal**

## WiMAX (continued)

**WiMAX (continued)**
- WiMAX is still a new technology and has not reached a high rate of adoption.
- Analysts predict that late 2006 will see more WiMAX carrier level devices available in the market.
- Currently there are other products that use the same concept, but with proprietary standards. These are known as *pre-WiMAX* technologies.

## WiMAX (continued)

**WiMAX (continued)**
- Main take-away: WiMAX and pre-WiMAX architectures still require wireline transport to a central office and commercial power.

## XIII. Wireless Options: 

**XIII. Wireless Options: **
**WiFi**

## Wireless Fidelity (WiFi):

- is IEEE 802.11b & 802.11g standards for fixed broadband wireless access with short reach
- reach is ~ 300’ depending on obstructions
- The WiFi signal is transmitted to and from a base station known as an access point
- uses the unlicensed 2.4GHz band radio frequency (cordless phones and microwave ovens use this same band)

**WiFi**

## WiFi

**WiFi**

**Distribution**
**Terminal**

**Service **
**Wire**

**Distribution cable/F2**

**Feeder cable**
**/F1**

**DLC**

**T-1**

**MUX**

**Fiber **
**Cable**

**FDI**

**DS3**

**DSLAM**

**CO**

**WiFi Router**

## WiFi (continued)

**WiFi (continued)**
- Allows users to gain wireless connectivity to a router – the access point. The router in turn can have a high-speed connection to an Internet Service Provider.
- WiFi works with:
- Laptops
- PDAs
- any WiFi-enabled devices
- A wireless Local Area Network (WLAN) is also known as a hotspot and uses WiFi technology.

## WiFi (continued)

**WiFi (continued)**
- There are many wireless routers in the market. Below i are two pictures of typical designs.

## WiFi (continued)

**WiFi (continued)**
- In short, WiFi merely replaces the Category 5e cabling from a laptop/PC to a router.
- The connection from the router to the central office is a wireline connection, and the router requires commercial power.

## XIV. Catastrophic Events & The Local Loop

**XIV. Catastrophic Events & The Local Loop**

## “Normal” Disasters

- Long-term loss of commercial power
- Flood & wind damage
- Damage or disability to road infrastructure

***“******Normal” Disasters***

## Status of BellSouth’s Network on 9/1/2005

**Status of BellSouth’s Network on 9/1/2005**
- 53 SONET rings were severed in multiple points
- 22 COs were either out of service or evacuated
- 38 CO switches were isolated from the SS7 network & unable to process inter-office calls
- 7 COs were on batteries, 151 on generators, some of which could not be accessed for refueling

## Downed service wires	  	141,182

**Summary of Damages to BellSouth’s Network**
- COs damaged or destroyed   	         33
- Poles damaged		  	  24,982
- Cable spans down	 	  	  66,465
- Downed service wires	  	141,182
- FDIs damaged			     750+
- DLC sites destroyed			         34
- Damaged distribution terminals	  33,000
- Feeder cable destroyed    1.9M sheath feet
- Sludge removed from manholes    830 tons

## Damaged & Destroyed Central Offices

## Damaged & Destroyed Central Offices

## XV. Recovery Efforts

**XV. Recovery Efforts**

## Recovery Efforts

**Equipment Shipped**
- 2,334 Truckloads of Network Equipment
**Generators Deployed**
- 1,044 Generators deployed multiple times
- Total of 333 truckloads of generators moved
**Fuel Distributed**
- 1.5M gallons of diesel fuel for generators and vehicles
- 1M gallons of unleaded gas for vehicles
- 43 Refueling Tankers, 27 above ground storage tanks
- 949 Additional Vehicles Provided

**Recovery Efforts**

## Recovery Efforts (continued)

**Temporary Telephony**
- Deployed portable DLC Equipment
- DLC & MUX in cabinet; powered by generator; backhaul is microwave transmission (known as “SLC on Wheels”)
- Wireless POTS
- Works like a local POTS phone, but connects to the cellular network
- Phone is AC powered
- Allows customers to forward their regular phone number to the wireless POTS phone to facilitate communications with relatives & friends, insurance companies, etc.
- Requires a functioning cell system

**Recovery Efforts (continued)**

## Recovery Efforts (continued)

**Temporary Internet Access**
- Deployed pre-WiMAX technology to serve returning homeowners served by damaged wireline plant
- Wireless Broadband
**Temporary Restoration of Links to Cell Sites**
- Deployed optical T-1s

**Recovery Efforts (continued)**

## Recovery Efforts (continued)

**Business Processes**
- Set up teams throughout the region to handle millions of transactions:
- Billing credits
- New connections
- Disconnections
- Employee assistance
- Approval of temporary technologies
- Many other operations and administration functions that are critical to operations

**Recovery Efforts (continued)**

## XVI. References & Glossary

**XVI. References & Glossary**

## www.fcc.gov/cgb/

- www.wikipedia.com
- www.howstuffworks.com
- www.itu.int
- www.iec.org

**Resources to Learn More**
**About Telecommunications**

## A/D – Analog-to-Digital conversion

- D/A – Digital-to-Analog conversion
- DLC – Digital Line Carrier
- DS0 – Digital Signal level 0
- DS1 – Digital Signal level 1
- DSL – Digital Subscriber Line
- DSLAM – DSL Access Multiplexer
- FDI – Feeder-Distribution Interface
- FTTC – Fiber to the curb
- FTTH – Fiber to the home
- FTTP – Fiber to the premises
- LAN – Local Area Network
- MUX - Multiplexer
- NID – Network Interface Device
- POTS – Plain Old Telephone Service
- PSAP – Public Service Answering Point (911 Center)
- PSTN – Public Switched Telephone Network
- SAI – Serving Area Interface
- WiFi – Wireless Fidelity
- WiMAX – Worldwide interoperability for Microwave Access

**GLOSSARY OF ACRONYMS**