Document:

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                                                                   EXHIBIT 10.43

                            MASTER LEASE AGREEMENT
                            ----------------------
                             (Multiple Locations)

This Master Lease Agreement ("Agreement") is entered into as of the 31st day of
August, 2000 (the "Effective Date"), between iPCS Wireless, Inc., an Illinois
corporation, together with any of its designated subsidiaries and affiliates
that may hereafter enter into a Site Lease (collectively "Lessee"), and Trinity
Wireless Towers, Inc., a Texas corporation, together with its designated
subsidiaries and affiliates (collectively "Lessor").

                                   RECITALS

     WHEREAS Lessee, through certain affiliation agreements, is licensed by the
Federal Communications Commission ("FCC") to construct and operate wireless
communications systems throughout the United States.

     WHEREAS Lessor owns, operates, leases, and/or manages various portions of
real property throughout the United States, including, buildings, towers (each a
"Tower"), tanks, and/or other improvements ("Improvements") thereon (each a
"Site").

     WHEREAS Lessor desires to lease certain Sites to Lessee for the purpose of
installing, operating, and maintaining communications facilities and services
thereon.

     WHEREAS Lessee desires to lease certain Sites from Lessor for such purpose.

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto agree as
follows:

     1.   Master Lease. This Agreement sets forth the basic terms and conditions
          ------------
upon which each Site or portion thereof is leased by Lessor to Lessee.

     2.   Application. At such time as Lessee identifies a Site, Lessee shall
          -----------
complete a site application (the "Application") in the form attached hereto as
Exhibit B, and incorporated herein by this reference. Lessee shall attach the
specifications for its proposed equipment to the Application. Lessor shall
notify Lessee in writing of its acceptance of the Application ("Approved Site").

     3.   Site Lease. For each Approved Site, Lessee and Lessor shall execute a
          ----------
site lease in substantially the same form as attached hereto as Exhibit A (each
a "Site Lease"). The terms and conditions of the Site Lease shall govern and
control in the event of a discrepancy or inconsistency with the terms and
conditions of this Agreement. Upon execution of a Site Lease, Lessor hereby
leases to Lessee, and Lessee leases from Lessor, (a) space on the Approved Site
as more particularly described in such Site Lease, (b) space on the related
Improvements, (c) a non-exclusive right and easement for pedestrian and
vehicular ingress and egress, and (d) a non-exclusive easement for utilities as
described in the Site Lease (collectively, the "Premises"). The Approved Site
shall be described or depicted in Schedule 1, attached to and incorporated into
each individual Site Lease, and the Premises, including any and all access and
utilities easements, shall be described or depicted in Schedule 2, attached to
and incorporated into each individual Site Lease.

Master Agreement Illinois (PCS)

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     4.   Tests, Approvals, and Permits.
          -----------------------------

     (a)  Lessor will provide Lessee with any information in its possession
regarding the Approved Site. Such information shall be provided for
informational purposes only, and may include, but shall not be limited to, lease
agreements, title documents, soils, environmental reports, FAA approvals, tower
drawings, foundation drawings, site plans, and construction drawings.

     (b)  Lessee is permitted, at its option and expense, to obtain a title
report or title commitment, soil boring, percolation or other tests or reports
of the Approved Site as are deemed appropriate by Lessee to determine the
physical characteristics and conditions thereof. The data and the results of
these tests shall be given to Lessor, and both parties shall treat this material
in a confidential manner.

     (c)  Prior to the construction of Lessee's Facilities, Lessor, in its
reasonable discretion, may require Lessee to obtain a structural analysis of the
Tower for Lessor's approval, which approval shall not be unreasonably withheld.
Such structural analysis shall be performed by a vendor approved in writing by
Lessor and shall include any existing equipment on the Tower. In the event the
structural analysis indicates that the Tower is not of sufficient strength to
support Lessee's intended use of the Tower, Lessee may either (a) terminate the
Site Lease, or (b) upon Lessor's prior written approval, enhance the Tower to
support such equipment. All enhancements to the Tower shall become Lessor's sole
property upon installation.

     (d)  Lessor shall also provide Lessee copies of any and all approvals
and/or permits obtained by Lessor ("Lessor's Approvals"). Lessee shall determine
whether additional governmental licenses, permits, approvals or other
certification or documentation ("Additional Approvals") is required for Lessee's
use of the Premises, and is responsible for obtaining such Additional Approvals
at its sole cost and expense. Lessor agrees to cooperate with Lessee, at
Lessee's expense, in making application for and obtaining all licenses, permits,
and any and all other necessary approvals that may be required for Lessee's
intended use of the Premises.

     5.   Prime Lease. If Lessor leases the Approved Site, Lessor shall provide
          -----------
Lessee with a copy of its lease and any necessary consent to any Site Lease (the
"Prime Lease"), which will be attached to and incorporated into the Site Lease
as Schedule 6. Lessor shall diligently pursue the written consent of its lessor,
if such consent to the Site Lease is required under the Prime Lease. Such
written consent shall be attached to the Prime Lease and included in Schedule 6
to the Site Lease. Notwithstanding anything to the contrary contained in this
Agreement or in each individual Site Lease, this Agreement and all of Lessee's
rights and obligations hereunder are expressly under and subject to the Prime
Lease. In the event the Prime Lease expires or is terminated, the respective
Site Lease shall terminate as between Lessor and Lessee on the effective date of
termination of the Prime Lease, and Lessor shall have no liability to Lessee
therefor, unless such termination is due to the intentional misconduct of
Lessor. Lessor shall give Lessee written notice of such termination or
expiration of the Prime Lease in accordance with paragraph 24(d) below. This
Agreement, including any Site Lease, is subordinate and inferior to the Prime
Lease, and Lessee will execute any documents reasonably requested by Lessor in
furtherance thereof.

     6.   Term. Unless otherwise specified in the Site Lease, the term of each
          ----
Site Lease shall be five (5) years commencing upon the later to occur of: a) the
date Lessor completes construction of the Improvements, or b) on the date both
parties have executed the Site Lease, ("Commencement Date") and terminating on
the fifth (5th) anniversary of the Commencement Date (the "Term") unless
otherwise terminated as provided herein. Unless otherwise provided in the Site
Lease, Lessee shall have the right to extend the Term for four (4) successive
five (5) year periods (each a "Renewal Term") on the same terms

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and conditions as set forth herein. Each Site Lease shall automatically renew
for each successive Renewal Term unless Lessee provides written notice to Lessor
of its intention not to renew at least thirty (30) days prior to the expiration
of the Term or any Renewal Term.

     7.   Rent. Within fifteen (15) days of the Commencement Date and on the
          ----
first day of each month thereafter, Lessee shall pay to Lessor rent in
accordance with each Site Lease ("Rent"). Rent shall be payable to Lessor as
provided in the Site Lease, or at such other address as Lessor shall notify
Lessee in accordance with Paragraph 24(d) below. Rent for any fractional month
at the beginning or at the end of the Term or Renewal Term shall be prorated.
Rent shall increase at the rate of four percent (4%) per annum as of each
anniversary date of the Commencement Date. Rent shall be due irrespective of any
default by Lessor; however, in the event of default, Lessee may pay Rent to a
mutually agreeable escrow agent until such time as such default is cured in
accordance with Paragraph 13 of this Agreement.

     8.   Facilities; Access; and Utilities.
          ---------------------------------

     (a)  Upon execution of a Site Lease, Lessee may erect, maintain, repair,
replace, modify and operate on the Approved Site radio communications
facilities, including without limitation, air conditioned equipment shelters and
rooms, utility lines, transmission lines, electronic equipment, radio
transmitting and receiving antennas, and supporting equipment and structures
thereto ("Lessee's Facilities"). All such equipment shall be identified in
Schedule 3 attached to the Site Lease and incorporated therein (the
"Equipment").

     (b)  Title to the Lessee's Facilities shall be held by Lessee. All of
Lessee's Facilities shall remain Lessee's personal property and are not
fixtures. Upon notice to Lessor, Lessee has the right to remove all Lessee's
Facilities at its sole expense on or before the expiration or earlier
termination of each Site Lease; provided, Lessee repairs any damage to the
Premises caused by such removal.

     (c)  Lessee, Lessee's employees, agents, subcontractors, lenders and
invitees shall have access to the Premises without notice to Lessor twenty-four
(24) hours a day, seven (7) days a week, at no charge; provided however, Lessee
must contact Lessor to schedule a time to install, modify, or remove Lessee's
Facilities.

     (d)  Unless otherwise specified in the Site Lease, Lessor shall maintain
all access roadways from the nearest public roadway to the Premises in a manner
sufficient to allow pedestrian and vehicular access at all times under normal
weather conditions. Lessor shall be responsible for maintaining and repairing
such roadway, at its sole expense, except for any damage caused by Lessee's use
of such roadways.

     (e)  Lessee shall obtain separate utility service, including electricity
and telephone lines, from any utility company that will provide service to the
Site (including a standby power generator for Lessee's exclusive use). Lessee
shall be responsible for obtaining its own meter or service for the utilities it
uses hereunder. Lessor agrees to sign such documents or easements as may be
required by said utility companies to provide such service to the Premises,
including the grant to Lessee or to the servicing utility company at no cost to
the Lessee, of an easement in, over across or through the Site as required by
such servicing utility company to provide utility services as provided herein.
Any easement necessary for such power or other utilities will be at a location
acceptable to Lessor and the servicing utility company.

     9.   Construction Liens. Lessee shall not permit any construction lien to
be filed against its interest under this Agreement, the Site Lease, or any
interest it holds in the Approved Site. If any such lien shall attach, Lessee
shall bond it over or otherwise cause it to be discharged within thirty (30)
days from the date of its filing. Nothing in this Agreement shall be deemed or
construed to give Lessee the

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right or authority to contract for, or authorize or permit the performance of,
any labor or services, or the furnishing of any material that would permit the
attaching of a construction lien to any interest in the Site.

     10.  Interference.
          ------------

     (a)  Based upon information which shall be supplied by Lessor prior to the
execution of any Site Lease and included in such Site Lease as Schedule 4,
Lessee will evaluate the possibility of interference to the Lessee's Facilities
at the Site from Lessor's current use of the Site and from other existing uses
of the Site. Lessee shall operate the Lessee's Facilities in a manner that will
not cause interference to Lessor and other lessees or licensees of the Site,
provided that their installations predate that of Lessee's Facilities. All
operations by Lessee shall be in compliance with all FCC requirements.

     (b)  Subsequent to the installation of Lessee's Facilities, Lessor shall
not permit itself, its lessees or licensees to install new equipment on the
Premises or property contiguous thereto owned or controlled by Lessor, if such
equipment is likely to cause interference with Lessee's operations. Such
interference shall be deemed a material breach by Lessor. In the event
interference occurs, Lessee shall send written notice to Lessor, and within
forty-eight (48) hours of receipt of such notice, Lessor agrees to take all
reasonable action necessary to eliminate such interference; provided however, in
the event such interference cannot reasonably be eliminated in said time period,
Lessor shall continuously and diligently work to eliminate the interference. In
the event Lessor fails to comply with this paragraph, Lessee may terminate the
affected Site Lease.

     11.  RF Compliance.
          -------------

     (a)  Based upon information which shall be supplied by Lessor prior to the
execution of any Site Lease and included in such Site Lease as Schedule 4,
Lessee will evaluate the possibility that the addition of the Lessee's
Facilities would cause the Site to exceed the FCC radiated power density maximum
permissible exposure ("MPE") limits for workers and the general public. Lessee
shall operate the Lessee's Facilities in a manner that will not cause the Site
to exceed the FCC specified MPE.

     (b)  Subsequent to the installation of Lessee's Facilities, Lessor shall
not permit itself, its lessees or licensees to install new equipment on the
Premises or property contiguous thereto owned or controlled by Lessor, if such
equipment is likely to cause the Site to exceed the MPE limits for the Site.
Such excess radiated power densities shall be deemed a material breach by
Lessor. In the event excess radiated power densities occur, Lessor agrees to
take, or to cause any subsequent lessee or licensee whose use of the Site
results in the FCC specified MPE limits being exceeded, to promptly take all
mitigation action necessary to eliminate such excess radiated power densities
within thirty (30) days. In the event Lessor fails to comply with this
paragraph, Lessee may terminate the affected Site Lease and/or pursue any other
remedies available under this Agreement and the Site Lease, at law, and/or at
equity, including injunctive relief.

     12.  Taxes. If personal property taxes are assessed, Lessee shall pay any
          -----
portion of such taxes directly attributable to Lessee's Facilities. Lessor shall
ensure that all real property taxes, assessments and deferred taxes on the Site
are paid. If any increase to Lessor's real property taxes is the direct result
of Lessee's improvements to the Site, then Lessee will reimburse the Lessor its
proportionate share of such tax increase provided that, as a condition of
Lessee's obligation to pay such tax increases, Lessor shall provide to Lessee
documentation from the taxing authority, reasonably acceptable to Lessee,
indicating that the increase is due to Lessee's improvements.

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     13.  Termination. A Site Lease may be terminated without further liability
          -----------
on thirty (30) days prior written notice as follows: (i) by either party upon a
default of any covenant or term thereof by the other party, which default is not
cured within sixty (60) days of receipt of written notice of default, provided
that the grace period for any monetary default is ten (10) days from receipt of
notice; or (ii) by Lessee for any reason or for no reason, provided Lessee
delivers written notice of early termination to Lessor no later than thirty (30)
days prior to the Commencement Date; or (iii) by either party if it does not
obtain or maintain any license, permit or other approval necessary for the
construction and operation of Lessee's Facilities; or (iv) by Lessee if Lessee
is unable to occupy and utilize the Premises due to an action of the FCC,
including without limitation, a take back of channels or change in frequencies.

     14.  Destruction or Condemnation. If the Premises or Lessee's Facilities
          ---------------------------
are damaged, destroyed, condemned or transferred in lieu of condemnation, Lessee
may elect to terminate the affected Site Lease as of the date of the damage,
destruction, condemnation or transfer in lieu of condemnation by giving notice
to Lessor no more than forty-five (45) days following the date of such damage,
destruction, condemnation or transfer in lieu of condemnation.

     15.  Insurance.
          ---------

     (a)  Lessee, at Lessee's sole cost and expense, shall procure and maintain
on the Premises and on the Lessee's Facilities, bodily injury and property
damage insurance with a combined single limit of at least One Million and 00/100
Dollars ($1,000,000.00) per occurrence. Such insurance shall insure, on an
occurrence basis, against liability of Lessee, its employees and agents arising
out of or in connection with Lessee's use of the Premises, all as provided for
herein.

     (b)  Lessor, at Lessor's sole cost and expense, shall procure and maintain
on the Site, bodily injury and property damage insurance with a combined single
limit of at least One Million Dollars ($1,000,000) per occurrence. Such
insurance shall insure, on an occurrence basis, against liability of Lessor, its
employees and agents arising out of or in connection with Lessor's use,
occupancy and maintenance of the Site.

     (c)  Each party shall be named as an additional insured on the other's
policy. Each party shall provide to the other a certificate of insurance
evidencing the coverage required by this paragraph within thirty (30) days of
the Commencement Date.

     16.  Waiver of Subrogation. Lessor and Lessee each hereby waives any rights
          ---------------------
it may have against the other (including, but not limited to, a direct action
for damages) on account of any loss or damage occasioned to Lessor or Lessee, as
the case may be (EVEN IF SUCH LOSS OR DAMAGE (A) IS CAUSED BY THE FAULT,
NEGLIGENCE, OR OTHER TORTIOUS CONDUCT, ACTS OR OMISSIONS [EXCLUDING GROSS
NEGLICENCE AND WILLFUL MISCONDUCT] OF THE RELEASED PARTY OR THE RELEASED PARTY'S
DIRECTORS, EMPLOYEES, AGENTS OR INVITEES AND/OR (B) THE RELEASED PARTY IS
STRICTLY LIABLE FOR SUCH LOSS OR DAMAGE), to their respective property, the
Site, or the Lessee's Facilities arising from any risk (without regard to the
amount of coverage or the amount of deductible) covered by the waiving party's
insurance which is in effect at the time of the loss or damage. Without in any
way limiting the foregoing waivers and to the extent permitted by applicable
law, the parties hereto, each on behalf of their respective insurance companies
insuring the property of either Lessor or Lessee against any such loss, waive
any right of subrogation that Lessor or Lessee or their respective insurers may
have against the other party or their respective officers, directors, employees,
agents, or invitees and all rights of their respective insurance companies based
upon an assignment from its insured. Lessor and Lessee each agrees immediately
to give their respective insurer written notification of the terms of the mutual
waivers

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contained in this paragraph and to have said insurance policies properly
endorsed, if necessary, to prevent the invalidation of said insurance coverage
by reason of said waivers.

     17.  Estoppel Certificate. Either party shall from time to time, within ten
          --------------------
(10) days after receipt of request by the other, deliver a written statement
addressed to the requesting party certifying:

     (a)  that this Agreement is unmodified and in full force and effect (or if
modified that this Agreement as so modified is in full force and effect);

     (b)  that the lease attached to the certificate is a true and correct copy
of this Agreement, and all amendments hereto;

     (c)  that to the knowledge of the responding party, the requesting party
has not previously assigned or hypothecated its rights or interests under this
Agreement, except as described in such statement with as much specificity as the
responding party is able to provide;

     (d)  the term of this Agreement and the Rent then in effect and any
additional charges;

     (e)  the date through which Lessee has paid Rent;

     (f)  that neither party is in default under any provision of this Agreement
(or if in default, the nature thereof in detail) and a statement as to any
outstanding obligations on the part of Lessor or Lessee; and

     (g)  such other matters as are reasonably requested.

Without in any way limiting the requesting party's remedies which may arise out
of the responding party"s failure to timely provide an estoppel certificate as
required herein, the responding party's failure to deliver such certificate
within such time shall be conclusive (i) that this Agreement is in full force
and effect, without modification except as may be represented by the requesting
party; (ii) that there are no uncured defaults in Lessee"s or Lessor's
performance hereunder; and (iii) that no Rent, except for the then current
month, has been paid in advance by Lessee.

     18.  Assignment and Subletting.
          -------------------------

     (a)  Except as provided herein, Lessee may not assign, sublet or otherwise
transfer all or any part of its interest in this Agreement or any Site Lease or
in the Premises without the prior written consent of the Lessor, which consent
shall not be unreasonably withheld, conditioned or delayed. Notwithstanding the
foregoing, Lessee may assign, upon notice to Lessee, and without the consent of
Lessor, its interest to its parent company, any subsidiary or affiliate of its
parent company or to any successor-in-interest or entity acquiring fifty-one
percent (51%) or more of its stock or assets, subject to any financing entity's
interest, if any. In the event of an approved assignment, Lessee shall be
relieved of all future performance, liabilities and obligations under this
Agreement, any Site Lease or in the Premises subject thereto.

     (b)  Lessor may assign this Agreement or any Site Lease upon written notice
as provided in paragraph 24(d) below, subject to assignee assuming all of
Lessor's obligations herein. Notwithstanding anything to the contrary contained
in this Agreement, Lessor may assign, mortgage, pledge, hypothecate or otherwise
transfer, without consent, its respective interests in this Agreement or any
Site Lease to any

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financing entity to whom Lessor (i) has obligations for borrowed money or in
respect of guaranties thereof, (ii) has obligations evidenced by bonds,
debentures, notes or similar instruments, or (iii) has obligations under or with
respect to letters of credit, bankers acceptances and similar facilities or in
respect of guaranties thereof.

     19.  Warranty of Title and Quiet Enjoyment. Lessor warrants that: (i)
          -------------------------------------
except as described in Schedule 5 and Schedule 6 of the Site Lease, Lessor owns
or has good leasehold interests in the Sites and has rights of access thereto;
(ii) Lessor has full right to make and perform this Agreement and each Site
Lease entered into pursuant to the terms hereof; and (iii) Lessor covenants and
agrees with Lessee that upon Lessee paying the Rent and observing and performing
all the terms, covenants and conditions on Lessee's part to be observed and
performed, Lessee may peacefully and quietly enjoy the Premises.

     20.  Repairs. Lessee shall make any repairs to the Premises or Site
          -------
necessitated by Lessee's or Lessee's agents, contractors, negligence, willful
misconduct, or intentional act. Upon expiration or termination of each Site
Lease, Lessee shall restore the Premises to the condition in which it existed
upon execution hereof, reasonable wear and tear and loss by casualty or other
causes beyond Lessee's control excepted.

     21.  Hazardous Substances. Lessee and Lessor agrees that they will not use,
          --------------------
generate, store or dispose of any Hazardous Material on, under, about or within
any Site in violation of any law or regulation. Lessor and Lessee each agree to
defend, indemnify and hold harmless the other and the other's partners,
affiliates, agents and employees against any and all losses, liabilities, claims
and/or costs (including reasonable attorneys' fees and costs) arising from any
breach of any representation, warranty or agreement contained in this paragraph.
As used in this paragraph, "Hazardous Material" shall mean petroleum or any
petroleum product, asbestos, any substance known by the state in which any Site
is located to cause cancer and/or reproductive toxicity, and/or any substance,
chemical or waste that is identified as hazardous, toxic or dangerous in any
applicable federal, state or local law or regulation. This paragraph shall
survive the termination of this Agreement.

     22.  Liability and Indemnity. Lessee and Lessor shall indemnify and hold
          -----------------------
the other harmless from all claims (including attorneys' fees, costs and
expenses of defending against such claims) arising from the acts or omissions of
the indemnifying party, its agents, employees, licensees, invitees, contractors,
or tenants occurring in or about the Site. In no event shall the liability of
Lessee or Lessor under this Agreement include damages for lost profits,
consequential or punitive damages. The duties and liabilities described in this
paragraph survive termination of this Agreement.

     23.  Marking and Lighting Requirements.
          ---------------------------------

     (a)  Lessor shall be responsible for compliance with all marking and
lighting requirements of the Federal Aviation Administration ("FAA") and the FCC
provided that if the requirement for compliance results from Lessee's
Facilities, Lessee shall pay for such reasonable costs and expenses (including
for any lighting automated alarm system). Should either party be cited because
the Site is not in compliance, and should the party causing the noncompliance
fail to cure the conditions of noncompliance, the non-responsible party may
either terminate the affected Site Lease or proceed to cure the conditions of
noncompliance at the other party's expense.

     (b)  If lighting requirements apply and a lighting automatic alarm system
has been installed by Lessor, Lessor shall allow Lessee to bridge-in to the
system to permit a parallel alarm or to install a second alarm (to the extent
permitted under the Prime Lease) if a bridge would not interfere with Lessor's
alarm. Lessee shall be responsible for the cost and expense of maintaining the
bridge or parallel alarm.

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Notwithstanding anything in this paragraph, the responsibility for compliance
with FAA and FCC requirements shall remain with Lessor as provided in Paragraph
23(a).

     24.  Lessee Financing. Lessor acknowledges and agrees that, notwithstanding
          ----------------
anything to the contrary contained in this Agreement:

     (a)  Lessee shall be permitted to pledge, mortgage, hypothecate or
otherwise grant a lien, security interest or collateral assignment (whether
pursuant to a security agreement, deed or trust, collateral assignment, mortgage
or other instrument) (a "Lien") in and to all right, title and interest of
Lessee in and to this Agreement, including, without limitation, the right to
occupy the Premises pursuant to the terms hereof, to Lessee's lender or lenders
and any successors and assigns or any refinancing or replacement lender
(hereinafter collectively called "Lenders") in connection with certain debt
financing to Lessee or to any of its affiliates or successors as security for
such debt financing.

     (b)  Lender shall be permitted to foreclose upon any such Lien (or accept
an assignment in lieu of foreclosure) and transfer and assign all right, title
and interest of Lessee in and to this Agreement pursuant to or subsequent to
such foreclosure and, in the event of any such foreclosure, transfer or
assignment, and provided Lender or its successor-in-interest expressly assumes
in writing and agrees to perform each of Lessee's covenants, duties and
obligations which will arise and accrue from and after the date of such
foreclosure, transfer or assignment, Lessor agrees that it will recognize Lender
or its successor-in-interest as the successor-in-interest to Lessee under this
Agreement as if Lender or its successor-in-interest (as applicable) were Lessee
under this Agreement.

     (c)  Lessor agrees and acknowledges that for so long as this Agreement
shall be in effect, Lessee (or the holder of Lessee's interest in this Agreement
shall own any and all improvements, buildings, structures and equipment on or
about the Premises, and Lessor waives any lien rights it may have concerning
Lessee"s Facilities which are deemed personal property and not fixtures, and
Lessee has the right to remove the same at any time without Lessor's consent.

     (d)  Lessor acknowledges that Lessee may enter into a financing arrangement
including promissory notes, financial and security agreements, operating or
financial lease agreements, for the financing of Lessee's Facilities
("Collateral") with a third party (and it may enter into other such arrangements
with other entities). Lessor (i) consents to the installation of the Collateral;
(ii) disclaims any interest in the Collateral and (iii) agrees that the
Collateral shall be exempt from execution, foreclosure, sale, levy, attachment,
or distress for any Rent due or to become due and that such Collateral may be
removed at any time without recourse or legal proceedings.

     (e)  All terms and provisions of clauses (a), (b), (c) and (d) preceding
shall enure to the benefit of Lender. Lessor shall, upon request by Lessee,
deliver to Lender a subordination agreement executed by Lessor consistent with
clause (d) and otherwise in a form reasonably acceptable to Lender and to
Lessor, pursuant to which Lessor subordinates any security interest or lien held
by Lessor in any personal property of Lessee located on the Premises to any
security interest or lien then held by Lender.

     (f)  In the event any other provision of this Agreement shall be in
conflict with the provisions of this Paragraph, the provisions of this Paragraph
shall control.

     25.  Miscellaneous.
          -------------

     (a)  This Agreement together with each Site Lease entered into pursuant to
the terms hereof constitutes the entire agreement and understanding between the
parties, and supersedes all offers,

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negotiations and other agreements concerning the subject matter contained
herein. Any amendments to this Agreement and each Site Lease must be in writing
and executed by both parties.

     (b)  If any provision of this Agreement or any Site Lease is invalid or
unenforceable with respect to any party, the remainder of this Agreement and/or
Site Lease or the application of such provision to persons other than those as
to whom it is held invalid or unenforceable, shall not be affected and each
provision of this Agreement and/or Site Lease shall be valid and enforceable to
the fullest extent permitted by law.

     (c)  This Agreement and each Site Lease shall be binding on and inure to
the benefit of the successors and permitted assignees of the respective parties.

     (d)  Any notice or demand required to be given herein shall be made by
certified or registered mail, return receipt requested, or reliable overnight
courier to the address of the respective parties set forth below:

     Lessor:             Trinity Wireless Towers, Inc.
                         2201 W. Royal Lane, Suite 210
                         Irving, Texas 75063
                         Attn: President

     With a copy to:     Trinity Wireless Towers, Inc.
                         2201 W. Royal Lane, Suite 210
                         Irving, Texas 75063
                         Attn: General Counsel

     Lessee:             iPCS Wireless, Inc.
                         11 Hawkeye Lane
                         Geneseo, IL  61254
                         Attn: Anthony Muscato

     Lessor or Lessee may from time to time designate any other address for this
purpose by written notice to the other party. All notices hereunder shall be
deemed received upon actual receipt.

     (e)  Each Site Lease and this Agreement as applied to that Site Lease shall
be construed in accordance with the laws of the county and state in which the
Site is located.

     (f)  Lessor acknowledges that a Memorandum of Lease in the form annexed
hereto as Exhibit C may be recorded by Lessee in the Official Records of the
city or county where the Premises is located; provided however, that Lessee
provide Lessor a copy of any such filing. Lessee may obtain title insurance on
its interest in the Premises. Lessor shall cooperate by executing documentation
required by the title insurance company.

     (g)  In any case where the approval or consent of one party hereto is
required, requested or otherwise to be given under this Agreement or any Site
Lease, such party shall not unreasonably delay or withhold its approval or
consent.

                                                                               9
<PAGE>

     (h)  The prevailing party in any litigation arising hereunder or under any
Site Lease shall be entitled to its reasonable attorneys' fees, expert witness
fees and court costs, including appeals, if any.

     (i)  If either party is represented by a real estate broker in this
transaction, that party shall be fully responsible for any fee due such broker,
and shall hold the other party harmless from any claims for commission by such
broker.

     (j)  All Riders and Exhibits annexed hereto form material parts of this
Agreement and each Site Lease.

     (k)  This Agreement and any Site Lease may be executed in duplicate
counterparts, each of which shall be deemed an original.

IN WITNESS WHEREOF, the parties have executed this Master Lease Agreement as of
the date first above written.

LESSOR                                       LESSEE

TRINITY WIRELESS TOWERS, INC.,               iPCS Wireless, Inc.
a Texas corporation                          an Illinois corporation

       /s/ Tracy Schrader                           /s/ Anthony R.Muscato
--------------------------------             ---------------------------------
By:    Tracy Schrader                        By:    Anthony  R. Muscato
--------------------------------             ---------------------------------
Title: Vice President                        Title: Senior Vice President and
--------------------------------             ---------------------------------
                                                    Chief Technical Officer
--------------------------------             ---------------------------------
Date:  December 29, 2000                     Date:  December 29, 2000
--------------------------------             ---------------------------------

                                                                              10
<PAGE>

                                 Exhibit List
                                 ------------

EXHIBIT A --  Site Lease

      SCHEDULE 1 -- Description of Site
      SCHEDULE 2 -- Description of Premises
      SCHEDULE 3 -- Equipment
      SCHEDULE 4 -- RF Information
      SCHEDULE 5 -- Existing Mortgages, Rights of Way, and Easements
      SCHEDULE 6 -- Prime Lease and Owner Consent

EXHIBIT B -- Application for Location of Trinity Wireless Towers' Site

EXHIBIT C -- Memorandum of Lease

                                                                              11<PAGE>

                                                                   EXHIBIT 10.44
                                                                   -------------

          FIRST AMENDMENT TO AGREEMENT REGARDING CONSTRUCTION, SALE AND
          -------------------------------------------------------------
                              LEASEBACK OF TOWERS
                              -------------------

     This First Amendment is entered this ___ day of November, 2000 between iPCS
Wireless, Inc., a Delaware corporation (successor by merger to Illinois PCS, LLC
and referred to herein as "ILPCS") and American Tower Corporation, a Delaware
corporation (herein "Purchaser") to amend that certain Agreement Regarding
Construction, Sale and Leaseback of Towers entered between ILPCS and Purchaser
dated May 28, 1999 (the "Agreement").

     WHEREAS, The parties desire to modify certain provisions of the Agreement
and wish to set out the terms thereof in writing;

     NOW, THEREFORE, In consideration of the foregoing and of the covenants
contained herein, the parties agree as follows:

1.   Amended Purchase Price for Certain Towers. Provisions of paragraph 1(c)
     -----------------------------------------
of the Agreement specify that the Purchase Price for each Tower shall be
$250,000, adjusted as provided in the Agreement. The parties agree that any
Tower purchased by Purchaser pursuant to the Agreement that has, or had at the
time of closing on such Tower prior to the date hereof, an extendable height of
249 feet (herein a "249' Extendable Tower") shall be purchased for a price of
$272,000, and that the $250,000 Purchase Price currently specified in the
Agreement shall not apply to any such Tower. The parties acknowledge that as of
the date of execution of this First Amendment the Tower sites designated on
attached Exhibit A have 249' Extendable Towers located on them, and that Exhibit
         ---------
A also lists the 249' Extendable Towers, if any, with respect to which closing
has already occurred and for which a $22,000 additional payment adjustment shall
be made by Purchaser to ILPCS within ___ days after the execution hereof. All
references in the Agreement to the defined term Purchase Price as it applies to
any 249' Extendable Tower shall be construed to refer to the $272,000 Purchase
Price for all purposes, unless context requires otherwise. All references in the
Agreement to the defined term Tower shall be construed to include any 249'
Extendable Tower for all purposes, unless context requires otherwise.

2.   Term.  The term of the Agreement set out in paragraph 2 is hereby modified
     ----
and extended to February 28, 2001.

3.   Notices.  The provisions of paragraph 17(c) regarding Notices are hereby
     -------
modified to delete the requirement that notice be provided to Nortel Networks,
Inc. and to provide that notice to ILPCS shall be given as follows:

                  iPCS Wireless, Inc.
                  1900 E. Golf Road, Suite 900
                  Schaumburg, IL 60194
                  Attn:  Anthony R. Muscato
                  Telecopy No.: (847) 517-1429
<PAGE>

4.   Counterparts.  This First Amendment may be executed in counterparts, each
     ------------
of which shall be an original document, but all of which taken together shall
constitute one and the same document.

5.   No Other Changes. Except as otherwise modified hereby, all other provisions
     ----------------
of the Agreement shall remain unchanged and continue in full force and effect.

     IN WITNESS WHEREOF, The parties have executed this First Amendment as of
the day and year first set forth above.

"Purchaser"                              "ILPCS"

AMERICAN TOWER CORPORATION,              iPCS Wireless, Inc.
a Delaware corporation                   a Delaware corporation

By:    /s/ John J. Peterman              By:    /s/ Anthony R. Muscato
       -------------------------                ------------------------------

Name:  John J. Peterman                  Name:  Anthony R. Muscato
       -------------------------                ------------------------------

Title: Vice President                    Title: Senior Vice President and CTO
       -------------------------                ------------------------------
<PAGE>

                                    EXHIBIT A
                                    ---------

                           (List of towers attached.)

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00022-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00022-of-00352.parquet"}]]