LAWLER, METZGER, KEENEY & LOGAN, LLC

STEPHEN J. BERMAN

PHONE (202) 777-7730

2001 K STREET, NW

SUITE 802

WASHINGTON, D.C. 20006

PHONE (202) 777-7700

FACSIMILE (202) 777-7763

October 12, 2012

Via Electronic Filing in ULS

Marlene H. Dortch, SecretaryFederal Communications Commission445 Twelfth St. SWWashington, DC 20554

Re: Nextlink Wireless, LLC – Amended Substantial Service Showing and Notification of Completion of Construction – Call Sign WPLM415; ULS File No. 0005240150

Dear Ms. Dortch:

Nextlink Wireless, LLC (“Nextlink”) hereby amends the above-referenced notification of completion of construction originally filed May 30, 2012, to provide the additional information requested by the Federal Communications Commission’s (“FCC’s”) letter of August 15, 2012.

By this amendment, Nextlink is providing a new Exhibit C to this application, which includes the additional information requested by the FCC’s letter regarding the model number of the Exalt Communications transmitter used by Nextlink and the link budget equation used to calculate the reliability of transmissions to the furthermost receive site. The Substantial Service Showing and Map in the attached Exhibits A and B are unchanged from Exhibits A and B attached to the original filing, except for one minor correction to Exhibit B. The original filing referenced a maximum TX power of 20 dBm at the bottom of page 1 of Exhibit B, while the range calculations were actually based on 21 dBm; therefore, the attached Exhibit B corrects the reference. This correction does not change the population coverage originally reported in Nextlink’s May 30 filing.

If you have any questions or require any additional information, please do not hesitate to contact the undersigned at 202-777-7730 or sberman@lawlermetzger.com.

Sincerely,

/s/ Stephen J. BermanStephen J. BermanCounsel to Nextlink

Page 1

Nextlink Wireless, LLC Demonstration of Substantial Service

Local Multipoint Distribution Service (LMDS)

Exhibit A

Substantial Service Showing

Nextlink Wireless, LLC (“Nextlink”), holds the Local Multipoint Distribution Service (LMDS) B-Block license (31.0-31.075 GHz, 31.225-31.300 GHz) for Basic Trading Area BTA461, Washington, DC, under call sign WPLM415. Nextlink has established a Point-to-Multipoint Hub in this BTA and has designed this Hub to provide wireless Ethernet and private line access, as well as high-speed, wide-area networking to customers throughout the portion of the BTA as designated in Exhibit B. The actual routes in the network vary depending on customer demand and line-of-sight constraints.1

Nextlink’s Wireless Network. Nextlink and XO Communications, LLC (“XO”) (an operating affiliate of Nextlink) remain committed to the development of Nextlink’s licensed LMDS spectrum. Nextlink is actively utilizing this valuable asset throughout the country, having deployed over 750 links throughout its LMDS service areas. In addition to maintaining its existing links, Nextlink continues to deploy additional links throughout its service areas.

Nextlink’s wireless microwave services are marketed directly through a 900 person sales force as well as through a well-developed network of agents. XO’s website actively promotes broadband wireless access through the network and provides specific product information and guides to business solutions using LMDS spectrum. In addition, Nextlink has developed and maintains the “LMDSxchange” (http://www.lmdsxchange.com/, patented) as a resource for potential customers interested in obtaining access to microwave spectrum on a link by link basis. The LMDSxchange enables such entities to identify and lease the necessary frequencies for point-to-point links within Nextlink’s licensed BTAs.

Nextlink and XO have developed a wide range of tools, services, and processes to install and monitor Nextlink’s wireless network. These wireless circuits are integrated into XO’s Network Operations Center through monitoring tools and procedures. Nextlink and XO have a

1 In April 2008, the Wireless Telecommunications Bureau (“WTB”) extended the substantial service deadline for numerous LMDS licenses to June 1, 2012. Call sign WPLM415 and a number of other Nextlink LMDS authorizations were included in the WTB’s extension order. Nextlink has moved forward with construction in this BTA and hereby submits the instant substantial service demonstration. See Applications Filed by Licensees in the Local Multipoint Distribution Service (LMDS) Seeking Waivers of Section 101.1011 of the Commission’s Rules and Extensions of Time to Construct and Demonstrate Substantial Service; Petition of Members of the Rural LMDS Group for Waiver of Section 101.1011 of the Commission’s Rules and Extension of Construction Deadline; Request by Members of the LMDS Coalition for Waiver and Limited Extension of Deadline for Establishing Compliance with Section 101.1011(a) LMDS Substantial Service Requirements; Petition of IDT Spectrum, LLC for Waiver and Extension of Time to Meet Substantial Service Requirements Found in Section 101.1011 of the Commission’s Rules, Memorandum Opinion and Order, 23 FCC Rcd 5894 (WTB 2008).

Page 2

dedicated wireless staff of RF engineers, material specialists, and management personnel focused on Nextlink’s LMDS and 39 GHz assets.

Safe Harbor Showing. In its Second Report and Order in CC Docket No. 92-297, the FCC stated that “for an LMDS licensee that chooses to offer point-to-multipoint services, a demonstration of coverage to 20 percent of the population of its licensed service area at the 10-year mark would constitute substantial service.”2 As shown in Exhibit B, the LMDS infrastructure installed and service provided by Nextlink in the LMDS B Block in this BTA service territory covers an estimated population of 1,458,098 out of a total BTA population of 5,543,091. Therefore, Nextlink provides coverage to approximately 26.30% of the population in its licensed service area, which exceeds the 20 percent safe harbor substantial service requirement. Nextlink utilized 2010 Census Bureau data to determine the population of its licensed service area.

To determine the population coverage within the BTA, Nextlink utilized the U.S. Census Bureau 2010 TIGER/Line® Shapefiles for Census Blocks available through www.census.gov. The 2010 Census Block files are available at ftp://ftp2.census.gov/geo/tiger/TIGER2010BLKPOPHU/. Nextlink uses MapInfo® to calculate the population coverage from the Census Bureau Shapefiles. The 2010 BTA population is calculated utilizing the geographic identification data from wireless.fcc.gov and updating the information with the 2010 Census county information from the U.S. Census Bureau.

Nextlink uses hub antennae and remote antennae that are manufactured by Radio Waves, Inc. In addition, Nextlink uses the Exalt A3/B band TDD radio manufactured by ExaltCommunications. The coverage contour, illustrated on the map in Exhibit B, is achieved using one (1) hub with 180° coverage. The coordinates of the LMDS hub are set forth in Exhibit B under the heading “Hub Location Details.” The signal strength in the BTA varies from a maximum strength of 34.6 dBm to no less than -80 dBm.

Nextlink utilized Pathloss planning tool software for maximum distance calculation for determining population coverage in each BTA. This methodology includes TX and RX antenna size/gain, frequency, transmit power, polarization, target BER, and rain rate as inputs. It calculates the maximum link distance and predicted signal strength at the maximum distance (i.e., clear air, no rain) for each modulation scheme. Nextlink used MapInfo mapping software to provide a graphical representation of the calculated maximum distance coverage.

The foregoing, in conjunction with Exhibit B, demonstrates that Nextlink has satisfied the safe harbor substantial service requirements with respect to the LMDS license bearing the call sign WPLM415.

2 Rulemaking to Amend Parts 1,2,21, and 25 of the Commission’s Rules to Redesignate the 27.5-29.5 GHz Frequency Band, to Reallocate the 29.5-30.0 GHz Frequency Band, to Establish Rules and Policies for Local Multipoint Distribution Service and for Fixed Satellite Services; Petitions for Reconsideration of the Denial of Applications for Waiver of the Commission’s Common Carrier Point-to-Point Microwave Radio Service Rules; Suite 12 Group Petition for Pioneer Preference, Second Report and Order, Order on Reconsideration, and Fifth Notice of Proposed Rulemaking, 12 FCC Rcd 12545, ¶ 270 (1997).

Page 1

Exhibit B

Washington, DC, BTA461, Call Sign WPLM415

Population Coverage: 26.30%Population Covered: 1,458,098Total Population: 5,543,091

Hub Location Details:• Coverage achieved using one (1) Hub with 180° coverage located near LAT

38.90472222, LONG -77.03305556• Address: 1120 Vermont Avenue, Washington, DC• Coverage uses 2, 90° sector antennae (14.6 dBi gain) as TX antennae, with 0 and 270

degree center azimuths, 4’ parabolic antennae (49 dBi gain) as RX antennae, and an ExaltExplore Air A3/B Band radio with maximum TX power of 21 dBm with -80 dBm RX Threshold.

Page 2

Hub Coverage:• Population @ 99.5% availability: approx. 1,458,098 (approx. 26.30% of BTA

population)• ITU Rain Zone K

Avail Rain Zone Max Distance QPSK (Radius)i

99.5% K 13.5 milesPopulation Data Source: U.S. Census Bureau, 2010 Population Estimates, Census 2010.

iBased on Manufacturer’s (Exalt Communications) Guidelines.

Page 1

Exhibit C

Washington, DC, BTA461, Call Sign WPLM415

The model of the transmitter that will be used by Nextlink in BTA461 is Exalt Communications ExploreAir rc31100.

The link budget equation for BTA461 is attached. For BTA461, Nextlink used the same link budget methodology that it uses for all of its commercial deployments:

Using Pathloss 4.0 software and accepted industry practices, Nextlink calculated a link budget for each location.

Nextlink established the hub location and selected a theoretical location at the margin of the coverage area. Antenna height for the remote location was assumed to be 50 feet.

The link budget is calculated at the maximum distance from the hub to give a 99.5% or better annual availability. The distance, or path length, from the transmit site to the furthermost receive site is reflected on the attached.

The frequency selected was in the first block in the appropriate band.

The antenna and radio parameters were provided by their respective manufacturers, namely RadioWaves and Exalt Communications.

Geoclimatic factor and fade occurrence factor (Po) are based on the geography of the location.

The link budget calculations are based on rain region guidelines from the International Telecommunications Union (ITU) to determine the availability of a microwave link. The ITU-R P530-7 rain model is used to determine 0.01% rain rate (mm/hr) for a given BTA. ITU-R P.530-7/8 is the reliability method used to determine the annual availability of the link.

Hub Remote

Latitude 38 54 17.00 N 39 03 29.16 NLongitude 077 01 59.00 W 077 11 19.96 W

True azimuth (°) 321.64 141.54

Antenna model HGSN28HV180EXR HP4-28Antenna height (ft) 50.00 50.00Antenna gain (dBi) 14.60 49.00

Frequency (MHz) 31012.50Polarization Vertical

Path length (mi) 13.50Free space loss (dB) 149.04

Atmospheric absorption loss (dB) 2.05Net path loss (dB) 87.49 87.49

Radio model rc31100 rc31100TX power (watts) 0.13 0.13TX power (dBm) 21.00 21.00

EIRP (dBm) 35.60 70.00Emission designator 25M0W7D 25M0W7DRX threshold criteria BER 10-6 BER 10-6

RX threshold level (dBm) -80.00 -80.00

RX signal (dBm) -66.49 -66.49Thermal fade margin (dB) 13.51 13.51

Geoclimatic factor 1.25E-06Path inclination (mr) 0.00

Fade occurrence factor (Po) 1.73E-02Average annual temperature (°F) 55.00

Worst month - multipath (%) 99.92279 99.92279(sec) 2028.97 2028.97

Annual - multipath (%) 99.97877 99.97877(sec) 6695.61 6695.61

(% - sec) 99.95754 - 13391.21

Rain region ITU Region K0.01% rain rate (mm/hr) 42.00

Flat fade margin - rain (dB) 13.51Rain rate (mm/hr) 3.31

Rain attenuation (dB) 13.51Annual rain (%-sec) 99.55309 - 140937.46

Annual multipath + rain (%-sec) 99.51063 - 154328.67

Fri, Oct 05 2012WPLM415 - BTA461 - RZK - WashingtonDC - B.pl4Reliability Method - ITU-R P.530-7/8Rain - ITU-R P530-7