UMTS DNB RF Operation Guidelines

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ATT-002-290-370

UMTS DNB RF Operation Guidelines

Abstract:

This Guideline provides high level guidance for UMTS Distribu ted Node B (DNB) RF operation including

plumbing, ordering information, planning and installation issues.

Audience:

Product Name:

Effective Date: NA

Published : Issue 4, 06/22/11

Expires On:

Related Documents:

Canceled Documents:

Issuing Department: National RAN

Business Unit: NP&E

Points Of Contact: Ming Ho

Author(s):

See Contact List ATTUID

AT&T Practice ATT-002-290-370

Issue 4, 06/22/11

AT&T Proprietary (Internal Use Only)

Not for use or disclosure outside the AT&T companies, except under written agreement.

2011 AT&T Intellectual Property. All rights reserved.

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Table Of Contents

Reason For Current Issue

1. About This Document 1

1.1. Purpose 11.2. Scope 1

1.3. Audience 1

1.4. Related Documentation 1

2. Introduction 2

2.1. Ericsson UMTS DNB 4

2.1.1. Main Unit 4

2.1.2. Remote Radio Head 6

2.1.3. OBIF 7

2.2. ALU UMTS DNB83. DNB Ordering 10

4. DNB Installation 11

4.1. Sheltered Site 12

4.2. Outdoor Site 14

4.3. Rooftop Site 17

5. DNB Operation and Support 19

5.1. E-911 support 19

5.2. Cable and Sweep 19

5.3. RX-AIT 20

5.4. TMA Support 20

5.5. RET Support 20

5.6. Alarming 20

5.7. Battery Backup Requirements for DNB 20

6. Appendix A Transmit Power Limits in CMRS Bands 21

7. Appendix B American Wire Gauge (AWG) Table 21

8. Acknowledgements 22

9. Contact List 22

A.1. Document Specific Acronyms 23

A.2. Acronyms Dictionary 24

Revision Log 23

ACRONYMS 23


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Reason For Current Issue

Issue Number Date Description Published By

4 06/22/11 Updated with new hardware

and feature information.

mh8532

1. About This Document

1.1. Purpose

The purpose of this document is to provide RF equipment and operation guidelines for UMTS Distributed Node B (DNB).

1.2. Scope

This document addresses Distributed Node B ordering, equipment operation and installation guidance or practices. The

commissioning, administration and maintenance of DNB is beyond the scope of this document and should refer to DNB

vendors documents.

1.3. Audience

The audience for this document includes AT&T Mobility RF Planning, Equipment, Operation personnel, and contractors

involved with Distributed Node B installation and operation.

1.4. Related Documentation

The following documents are related to this document:

[1] PL-218 UMTS DNB Policy Letter

[2] Non-Standard Equipment Justification Form

[3] ATT-002-290-041 (ND-00026) RF Connector & Weatherproofing Guidelines

[4] ATT-002-290-383 ( ND-00071) Grounding Standard


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[5] ATT-002-290-142 (ND-00157) RF Surge Arrestor Guidelines

[6] ATT-002-290-043 (ND-00029) Antenna/Cable System Sweep MOP

[7] ATT-002-290-172 (ND-00194) RX-AIT Guidelines

[8] ATT-002-290-316 (ND-00354) PIM Measurement MOP

[9] ATT-002-290-150 (ND-00170) TMA Guidelines

[10] ATT-002-290-125 (ND-00135) RET Guidelines

[11] ATT-TELCO-002-200-381 Fiber Optic Connector & Adapter Inspection and Cleaning Tools & Procedures

[12] ATT-TELCO-JA-000-000-433 Understanding OTDR

2. Introduction

The Distributed Node B (DNB) is the next step in the evolution of the Classic/Macro Node B. The Original Equipment

Manufacturers (OEMs) have evolved their UMTS Node B platform to the distributed architecture, i.e., Remote Radio

Heads (RRH) and Baseband Unit (BBU). Looking forward LTE will offer only distributed architecture. AT&T's leadership

has made a strategic business decision to move forward with the Distributed Node B (DNB) deployment [1]. Figure 1 is

illustrating the DNBs evolution from the Macro architecture, DNBs components, advantages and challenges. Key DNB

advantages include the following:

Less footprint

Less power consumption

RRH can be close to antenna resulting less feeder loss


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Figure 1: DNB's evolution, components, advantages and challenges.

The Distributed Node B contains several major components:

Base Band Unit (BBU) or Main Unit (MU)

Remote Radio Head (RRH)

Mounting Kit/Set (rack, wall, pole, floor)

Power, fiber and alarm cables including Bias-T cables and daisy chain fiber jumpers

A BBU supports several RRHs based on Common Public Radio Interface (CPRI)

Footnote:Currently the protocols between RRH and BBU are OEM proprietary.

at a distance up to 15 km (~ 9 miles) to the 1st RRH. The overall can achieve up to 35 km.

NOTE:Initially , the distance between BBU and RRH will be limited to < 300m in order to meet E911 requirement.


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Figure 2: Comparisons between DNB and macro Node B.

2.1. Ericsson UMTS DNB

Ericsson UMTS DNB includes the following key products. Each BBU can support a maximum of 6 RRHs. The Transmitter

Board (TXB) and Random Access and Receive Board (RAXB) cards in the baseband unit are the same cards we currently

are using for the 3206 and 3106 deployment and so are T1, DS3 and Ethernet cards.

2.1.1. Main Unit

3418 Indoor Base Bans Unit (Figure 3)

Size H x W x D : 7 x 17.7 x 10.6

Weight: 45 lbs (fully equipped)

It can be mounted in 19 rack with 4U height.


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Figure 3: Ericsson Indoor Baseband Unit 3418.

3518 Outdoor Base Bans Unit (Figure 4)

Size H x W x D : 18.7 x 13.4 x 12.3 (includes fan)

Weight: 73 lbs (fully equipped)

Operating temperature range: -27 F to +122 F

Figure 4: Ericsson Indoor Baseband Unit 3518.

RBS 6601 is the next generation main unit. It is 1.5U height and is powered by -48 VDC. One RBS 6001 can house

a DUW-30 as shown in Figure 5.

Weight is less than 22 lbs with DUW.

Size: 2.6 x 19 x 13.8


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Operating temperature range: 41 F to +122 F

Figure 5: 6601 w DUW.

2.1.2. Remote Radio Head


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RRUW Remote Radio Head supports 2 carriers at up to 60 W total. The 1st generation Ericsson RRU22 can be replaced

with RRUW without any issue. Please make sure to use the correct Radio Building Block.

Size (including sun shield): 25 x 15 x 6.7

Weight (including sun shield): 44 lbs (20 kg)

Support co-siting ports: RXA I/O, RXB I/O and RXAOUT that can be configured either as input or output.

NOTE:RXAOUT gain (18 dB) is 1 dB hotter than RXA I/O (17 dB).

NOTE:Ericsson RRH like RRU22 and RRUW should be mounted vertically with clearance distances specified by Erics-

son documents even they are installed inside the shelter to ensure proper airflow.

2.1.3. OBIF

OBIF Optic Baseband Interface can be used to expand existing macro Node B to support up to six additional RRUW's

for UMTS carrier-added application. The OBIF board will be installed in the 2nd baseband pool of macro Node B.


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Figure 6: Exemplary OBIF configuration.

2.2. ALU UMTS DNB

Alcatel-Lucent DNB includes the following key products. ALU DNB cannot support more than 6 sector carriers due to the

limitation of three UCU-III cards.

9396 d2U Base Band Unit (Figure 7)

Size H x W x D : 15.7 x 17.3 x 3.5

Weight: 25 lbs

It can be mounted in 19 rack with 2U height.


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Figure 7: ALU Base Band Unit: 9396 d2U

9396 d2U Outdoor Enclosure (Figure 8)

Size H x W x D : 18.9 x 24.6 x 7.9

Weight: 60 lbs

Operating temperature range: -40 F to +131 F

Figure 8: ALU BBU outdoor enclosure.

9341 RRH Remote Radio Head (Figure 9) at 40 W or 60 W output power. Daisy chain feature allows up to three

RRHs . Please note that there is no physical difference between 40 W and 60 W RRH. If someone needs to know,

they could call or check the WMS for the inventory of which one is on the site

850 MHz: 9.8 x 22.4 x 8.3, 53 lbs

1900 MHz: 9.8 x 18.1 x 8.3, 44 lbs

Weight (including sun shield): 64 lbs


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Figure 9: ALU RRH 9341.

3. DNB Ordering

Per Policy Letter - 218 [1], effective July 7th, 2009 all orders for the UMTS NodeB should go through the DNB/Macro

selection process for both Ericsson and ALU with known exceptions described in that document. This applies to all POR

and BAU sites. SCM is monitoring the DNB forecast and ordering. Typical lead time for DNB is 45 days

All DNB products should be ordered and processed using EPL and exception codes must be highlighted during

ordering process to alleviate any questions or delays.

All AC powered DNB ordering require exception process.

Footnote:ALU does not offer AC version DNB.

The recommended DNB spare is 1 per 100 deployed units based on MTBF data.

Please refer to the following URL for more details regarding DNB.

http://ns.cingular.net/sites/RFEng/tools_d.aspx


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4. DNB Installation

UMTS Remote Radio Heads (RRH) are NOT recommended for mounting at the top of towers except NSB sites.

Until further notice, distance between Remote Radio Heads (RRH) and BBU should be less than 300 m (~ 984)

due to the following concerns:

E911

Enterprise systems need to be evaluated in order to capture site data that reflects the distributed architecture

of the equipment. These Cadence, CASPR, CDMS, CinguLINC, CSSng, CTS, Granite, Guardian, MTi/Clarify,

NDR, NetCool, OSS, Scout, and Siterra.

ATT approved DNB will only be power by -48 VDC. DC-DC converter is needed if your existing power plant is 24

VDC. SCM and working to create the SKUs to support DNB power and ancillary equipment. For more details, please

refer to Cell Site Design Standards group link.

http://ns.cingular.net/sites/EngOpsSup/DistRecvCellSite/default.aspx

More vendor specific DNB documents such as product technical description, installation, operation and maintenance

can be found in the following URL:


All outdoor connections of the RRH require weatherproofing. These include RF, fiber and power interfaces. Please

refer to ATT-002-290-041 (formerly ND-00026) RF Connector and Weatherproofing Guidelines [3] for more details.

All DNB equipment must be properly grounded per vendors recommendation. ATT-002-290-383 (formerly

ND-00071) lists AT&T's Grounding Standards [4].

All DNB equipment should be installed with surge protection in RF and DC paths. Please refer to ATT-002-290-142

(formerly ND-00157) RF Surge Arrestor Guidelines [5] for more details.

When daisy chaining is required and multiple DNBs serve the same sector, it is possible to increase redundancy by

daisy chaining the 2nd DNB on a different sector. For example (assuming a 2 sector site), fiber run 1 feeds one DNB

on the A sector and then is cascaded to a DNB on the B sector. Fiber run 2 would feed a DNB on the B sector

then cascade to the DNB on the A sectors. This way, if one first DNB fails it takes out 50% of the A sector and

50% of the B sector instead of 100% of one sector.

Please refer to the following link for exemplary RF plumbing diagrams for DNB to support UMTS multi-carrier

deployment.

http://ns.cingular.net/sites/RFEng/tools_d.aspx?RootFolder=%2fsites%2fRFEng%2fDistributed%20Node%20B

%20DNB%2fRF%20Plumbing&View=%7b6D77F20C%2d5FA8%2d438D%2dBDD7%2d5E7AF4802C63%7d


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http://ns.cingular.net/sites/RFEng/tools_d.aspx?RootFolder=%2fsites%2fRFEng%2fDistributed%20Node%20B%20DNB%2fRF%20Plumbing&View=%7b6D77F20C%2d5FA8%2d438D%2dBDD7%2d5E7AF4802C63%7dhttp://ns.cingular.net/sites/EngOpsSup/DistRecvCellSite/default.aspxhttp://ns.cingular.net/sites/RFEng/tools_d.aspx?RootFolder=%2fsites%2fRFEng%2fDistributed%20Node%20B%20DNB%2fRF%20Plumbing&View=%7b6D77F20C%2d5FA8%2d438D%2dBDD7%2d5E7AF4802C63%7dhttp://ns.cingular.net/sites/RFEng/tools_d.aspx?RootFolder=%2fsites%2fRFEng%2fDistributed%20Node%20B%20DNB%2fRF%20Plumbing&View=%7b6D77F20C%2d5FA8%2d438D%2dBDD7%2d5E7AF4802C63%7dhttp://ns.cingular.net/sites/RFEng/tools_d.aspxhttp://ns.cingular.net/sites/EngOpsSup/DistRecvCellSite/default.aspx


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NOTE:Please note when operating the Distributed Node B, make sure the output ERP does not exceed FCC limit.

Appendix A lists more details.

4.1. Sheltered Site

Figure 10 depicts a typical DNB installation in a sheltered environment when the distance between the BBU and RRH is

less than 100.

Install the BBU inside the shelter on available rack or on the wall with supporting brackets.

RRH should be installed outside the shelter to reduce the load on HVAC. It can be installed on the wall, pole, floor

stand or frame. RRH should only be installed inside the shelter for legitimate reasons such as risk of theft, bullet

risk, extreme weather, additional lease cost, lack of hatch ports, or long feedline loss.

All cables pass through cable entry ports (pass-through holes) require sealing. These include RF, fiber and power

cables.

Use enclosure-type RF weatherproofing kit like RFS WSHIELD, 123eWireless EasySeal, Tyco GSIC or equiv-

alent for RRH to support easy removal/installation when troubleshooting or sweep is required.

The RRH RF output will be routed back into the shelter to diplexer, RX-AIT etc. then connected to hatchplate. For

NSB sites or sites with flexibility on the feeders or co-siting, it is not necessary to route RF jumper cables into the

shelter. The RF output of the DNB can be connected to feeders via short jumper cable directly.

RRH can power TMA and the configurations are same as existing Node B.

DNB RET functionality will not be used due to interoperability concern with existing RET antenna vendors. RETshould be powered or controlled by separate RET controller via RET Bias-T or dedicated AISG home-run cable.

It is noted that additional lease/rent may occur depends upon the contract and markets. National Real Estate group

is investigating any impact to MLA.


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Figure 10: Typical DNB installation in a sheltered environment when the distance between the BBU and

RRH is < 100'.

When the distance between the BBU and RRH is more than 100, it is recommended to install power and fiber demarcation

boxes outdoor as shown in Figure 11. The demarcation box provides cable interconnection management for cleaner

cabling and easy installation. DC surge protection may be included too. It will be more economical to put the surge

protectors on the distribution bars than the individual conductors when the RRH's are mounted on the tower (one surge

arrestor between the hot and return bar on the power plant and one between the return bar and the site ground) since all

DC pairs will have roughly the same induced voltage on them from a lightning strike. Additionally, install excess boxes to

loop extra length fiber cable that may be used when the RRHs are moved to the tower top later.


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Figure 11: Typical DNB installation in a sheltered environment when the distance between the BBU and

RRH is more than 100'.

4.2. Outdoor Site

Figure 12 depicts a typical DNB installation in an outdoor environment when the distance between the BBU and RRH is

less than 100.

Install outdoor BBU at location close to existing outdoor cabinets. It can be installed on the pole/frame, floor stand

or hanged on the cabinet wall. Approved outdoor cabinets are listed in the following


Install RRH close to the hatchplate or at the bottom of the tower. It can be installed on the pole or frame.

The fiber cable from BBU to RRH will have 12 pairs of fiber cable. Each RRH has its own fiber cable; daisy chain

connection is not recommended at this moment .


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Use enclosure-type RF weatherproofing kit like RFS WSHIELD, 123eWireless EasySeal, Tyco GSIC or equiv-

alent for RRH to support easy removal/installation when troubleshooting or sweep is required.

The RRH RF output will be connected to hatchplate via RF jumper cables.


DNB RET functionality will not be used due to the interoperability concern with existing RET antenna vendors. RET

should be powered or controlled by separate RET controller via RET Bias-T or dedicated AISG home-run cable.

Figure 12: Typical DNB installation in an outdoor environment when the distance between BBU and

RRH is < 100'.

When the distance between the BBU and RRH is more than 100, it is recommended to install power and fiber demarcation

boxes as shown in Figure 13. The demarcation box provides cable interconnection management for cleaner cabling andeasy installation. Additionally, install excess boxes to loop extra length fiber cable that may be used when the RRHs are

moved to the tower top later.


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Figure 13: Typical DNB installation in an outdoor environment when the distance between BBU and

RRH is > 100'.

Figure 14 also depicts an exemplary DNB layout for a 15 x 15 PAD. It includes a future battery cabinet and two future

RRH assemblies.


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Figure 14: Exemplary DNB layout in a 15' x 15' PAD.

4.3. Rooftop Site

Key advantages of deploying DNB at rooftop sites are crane is not needed for installation and no need for TMA if RRH

can be installed close to the antennas. Figure 15 depicts a typical DNB installation in a rooftop environment assuming

the distance between BBU and RRH is less than 100.

Install outdoor BBU at location convenient for network operations group to service. It can be installed on the pole or

floor stand or hanged on the cabinet wall.

Install RRH close to the antennas as possible. It can be installed on the pole or frame. Consider FCC limits on ERP

as outlined in Appendices A and B.


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When installing the RRH next to the antennas, TMA's may not be required. A new link budget should be calculated.

Please refer to TMA/GMA Guidelines [9] for more details.

The fiber cable from BBU to will have 12 pairs of fiber cable. Each RRH has its own fiber cable; daisy chain connection

is not recommended at this moment .

Use enclosure-type RF weatherproofing kit like RFS WSHIELD, 123eWireless EasySeal, Tyco GSIC or equiv-alent for RRH to support easy removal/installation when troubleshooting or sweep is required.

The RRH RF output will be connected to antenna via RF jumper cables.


DNB RET functionality will not be used due to the interoperability concern with existing RET antenna vendors. RET

should be powered or controlled by separate RET controller via RET Bias-T or dedicated AISG home-run cable.

Figure 15: Typical DNB installation in a rooftop environment.


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5. DNB Operation and Support

5.1. E-911 support

The distance between BBU and RRH should be less than 300m or less due to E911 concern. Like existing UMTS Node

B, E-911 support is handed off to GSM only for handsets without AGPS capability, and certain DNB configurations may

not operate correctly with E911. For handsets with AGPS capability, the E911 system falls back to a method called CGI

+RTT. That method uses RRH and signal path information to estimate handset location. Commercial location services

location estimates also use CGI+RTT with UMTS.

5.2. Cable and Sweep

DNB RF cable sweep will be same as exiting BTS or Node B. Please refer to ATT-002-290-043 Antenna/Cable

System Sweep MOP [6] for more details

Fiber optic cables are sensitive to mechanical stress, sharp bends, kinks, dust and dirt and require special care.

Use pre-terminated fiber cables available in a variety of lengths of each vendor. Do no twist the fiber cable at

minimum bending radius. Make sure not to apply excessive force to the cable for maximum tensile force values.

An optical interface Module ODTF-1 from Anritsu can be used with Anritsu BTS master or Site Master to perform

fiber cable DTF (OTDR) plus some dedicated fiber testers. More details will be provided after evaluations are

completed.

Power Cables should be sized according to cable run length to maintain less than a 4 volt DC round trip voltage

drop between the power system output terminals and the RRH input terminals. A current level equal to 80% of the

circuit breaker current rating specified shall be used for this calculation.

The following table shows the minimum power cable AWG (American Cable Gauge) depend upon the cable length.

Refer Appendix B for more AWG cable information.

Run Length Minimum AWG

0 to 100' AWG 12

100 to 150' AWG 10

150 to 250' AWG 8


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250 to 400' AWG 6

Over 400' Separate power near RRH may be considered.

Follow local market guidelines to mark all RF, fiber and power cables if applicable.

5.3. RX-AIT

No difference for RX-AIT configuration for DNB except RRH only support duplexed mode. That is, direct connection

method for Node B cannot be used for DNB. Please refer to ATT-002-290-172 RX-AIT Guidelines [7] for more details.

5.4. TMA Support

RRH can power TMA and the configurations will be similar to existing Node B settings . For more details regarding TMA

operation please refer to ATT-002-290-150 TMA Guidelines [9].

5.5. RET Support

We will not use DNBs RET capability due to no interoperability testing with our approved RET vendors were performed

yet. Currently, AT&T's only operates AISG 1.1 RET system. It should be powered and controlled through RET Bias-T or

dedicated AISG home-run cable. Please refer ATT-002-290-125 RET Guidelines for more details [10].

5.6. Alarming

Please refer to DNB OEM vendor documents for DNB alarming information. RRH can also support external alarms. DNB

alarming will be tested through FMS/NetCool and into the NOC.

ALU BBU supports 32 external alarms and each RRH supports six user alarms.

Existing Ericsson DNB does not support any external alarm. Next generation Ericsson BBU will support 32 external

alarms and each RRH can handle two external alarms.

5.7. Battery Backup Requirements for DNB

Cell site design standards regarding generators, power plant, batteries and cabinets are available in the following link:


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6. Appendix A Transmit Power Limits in CMRS Bands

Band Base Station Limit (urban) Base Station Limit (rural) Mobile Station Limit

800 MHz Cellular Part 22.913 500 W ERP 1000 W ERP 7 W ERP (typical GSM = 2W)

Upper 700 MHz Part 27.501000 W ERP (BW


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Figure 16: AWG Table

1 mil = one thousandth inch

8. Acknowledgements

A&P: Dan Edwards, Rob Taylor, Craig Palmer

C&E: Jeff Townend, Scott Whitney, Tom Aebersold, Rob Seawright, Chris Lee, Steve Kerr

NP&E:Stalin Albanes, Gerry Martinez, Kurt Huber, Ayman Mostafa, Kark Beck, Hristo Hristov

9. Contact List

Name ATTUID Phone # Department / Responsibility


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Ming-Ju Ho mh8532 404-499-5582 NP&E National RAN

Revision Log

Issue Number Date Description Published By

4 06/22/11 Updated with new hardware

and feature information.

mh8532

3 01/05/11 Please note that sd0987 is

not the owner/author of this

document. Sd0987 is onlycorrecting a technical error

as part of the APEx Strategy

Team. See name listed in

Author tag for content related

questions.

sd0987

2 12/10/10 Update with new DNB

hardware (e.g., OBIF) and

features

mh8532

Acronyms

A.1. Document Specific Acronyms

The following acronyms and terms are used in this document:

AWG American Cable Gauge

BAU Business as Usual

BBU Base Band Unit


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CPRI Common Public Radio Interface

DNB Distributed Node B

DTF Distance to Fault

DUW Digital Unit for WCDMA

LMU Location Management Unit

MLA Master Lease Agreement

NSB New Site Build

OBIF Optical Baseband InterFace

OTDR Optical Time Domain Reflection

POR Plan of record

RRH Remote Radio Head

RXAIT Receive Antenna Interface Tray

A.2. Acronyms Dictionary

Refer to ATT-000-000-020, Acronyms Dictionary.


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http://apex.web.att.com/bookview/bookview.jsp?bookname=ATT-000-000-020&section=atdoctitle