Document:

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                                                                   EXHIBIT 10.19

                      INTERCARRIER ROAMER SERVICE AGREEMENT
                      -------------------------------------

         THIS INTERCARRIER ROAMER SERVICE AGREEMENT (the "Agreement") is dated
as of the ________________, 2000 by and between AT&T Wireless Services, Inc., on
behalf of itself and its Affiliates listed in Schedule I hereto (individually
and collectively, "AT&T") and [HOLDING COMPANY], on behalf of itself and its
Affiliates listed in Schedule 2 hereto (individually and collectively,
"Company"). AT&T and Company are sometimes referred to, individually, as a
"Party" and together as "Parties."

                                 R E C I T A L
                                 -------------

         WHEREAS, each of AT&T and Company desire to make arrangements to
facilitate the provision of voice and voice-related mobile wireless
radiotelephone service to the customers of the other Party, while such customers
are using the wireless radiotelephone facilities of such Party, in accordance
with the terms of this Agreement;

         NOW, THEREFORE, in consideration of the mutual promises herein set
forth and intending to be legally bound hereby, the Parties do hereby agree as
follows:

                                    ARTICLE I

                                  DEFINITIONS
                                  -----------

As used in this Agreement, the terms below shall have the following meanings:

         Affiliate means, with respect to a Party, any facilities-based CMRS
         ---------
operating company that (a) is controlled by or under common control with the
Party, (b) is an entity in which the Party has at least fifty percent (50%)
voting interest, (c) shares switching facilities with the Party, (d) is managed
by the Party, or (e) is providing Service utilizing CMRS spectrum it has
acquired from a Party.

         Approved CIBERNET Negative File Guidelines means the negative file
         ------------------------------------------
guidelines appearing in the CIBER Record in effect from time to time.

         Authorized Receipt Point or "ARP" means the location or address of the
         ------------------------     ---
Party designated by the Home Carrier as the delivery point for its CIBER records
and authorized agent for performing CIBER edits.

         Authorized Roamer means a Roamer using equipment and an assigned
         -----------------
telephone number with the NPA/NXX combinations listed in accordance with Article
IV below for Serving Carrier has not received a negative notification in
accordance with the provisions of this Agreement.
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         CIBER means Cellular Intercarrier Billing Exchange Record.
         -----

         CIBER Record means the publication prepared by CIBERNET Corporation, a
         ------------
wholly-owned subsidiary of the Cellular Telecommunications Industry Association,
as a service to the wireless communications industry. Unless specifically
provided otherwise in this Agreement, all words and phrases defined in the CIBER
Record shall have the meaning herein that they have therein.

         Clearinghouse means that entity which provides for the exchange of
         -------------
CIBER records and performs industry accepted CIBER edits, including edits to
verify Industry Negative File information.

         CMRS means Commercial Mobile Radio Service.
         ----

         ESN means the Electronic Serial Number that is encoded in a wireless
         ---
telephone set by the manufacturer and which is broadcast by such telephone.

         Home Carrier means a Party who is providing Service to its registered
         ------------
customers in a geographic area where it holds a license or permit to construct
and operate a mobile wireless radiotelephone system and station.

         Industry Negative File means the negative file maintained by the
         ----------------------
authorized Clearinghouses in accordance with approved CIBERNET Negative File
Guidelines.

         MIN means the "Mobile Identification Number" which is assigned by a
         ---
Home Carrier to each of its registered customers.

         NPA/NXX combinations means the six-digit numerical combinations
         -------
assigned by regulatory authorities to identify the area code and telephone
number prefix for Service.

         Roamer means a customer of one Party who seeks Service within a
         ------
geographic area served by the other Party.

         Service means telecommunications service for the transmission and
         -------
reception of voice and voice-related features provided by means of radio
frequencies that are or may be licensed, permitted or authorized now or in the
future by the Federal Communications Commission (or any successor agency), and
in respect of which service the user equipment is capable of and intended for
usage during routine movement, including halts at unspecified points, at more
than one location throughout a wide area public or private wireless network.
Unless otherwise specifically agreed by the Parties, Service shall include
personal base station services but, by way of example and without limitation,
does not include fixed wireless services, two-way messaging wireless services
(NBPCS), video broadcasting wireless services, television services (whether
cable, broadcast or direct broadcast satellite), broadcast radio services,
interactive informational or transactional content services such as on-line
content network services, Internet based services, satellite based
communications services, and air to ground communications services.

                                       2
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         Serving Carrier means a Party who provides Service for registered
         ---------------
customers of another Party while such customers are in the geographic area where
the Serving Carrier, directly or through subsidiaries, provides Service.

                                   ARTICLE II

                              PROVISION OF SERVICE
                              --------------------

         2.1   Each Party shall provide, to any Authorized Roamer who so
requests, voice communication service and any and all other types of Service
that such Party provides to its own customers. Notwithstanding the foregoing,
the Serving Carrier shall not be required to modify or supplement its system in
any way to address any incompatibility in the technologies used by the Serving
Carrier and the Home Carrier that may preclude the provision of Service to an
Authorized Roamer. Service shall be provided in accordance with the Serving
Carrier's own ordinary requirements, restrictions, practices, and tariffs, if
applicable, and with the terms and conditions of this Agreement.

         2.2   Notwithstanding anything in this Agreement to the contrary, a
Serving Carrier may suspend or terminate Service to an Authorized Roamer in
accordance with the terms of its own ordinary requirements, restrictions,
practices, and tariffs, but such suspension or termination shall not affect the
rights and obligations of the Parties for Service furnished hereunder prior to
such termination or suspension.

         2.3   In connection with its Service to Roamers, no Serving Carrier
shall use recorded announcements or other inducements for an Authorized Roamer
to discontinue the Service of its Home Carrier or, unless otherwise authorized
herein, Roamer's use of a Serving Carrier's system.

         2.4   In the event that an operating entity becomes an Affiliate of a
Party after the date of this Agreement, such Party may, upon thirty (30) days
prior written notice to the other Party, add such operating entity to Schedule 1
or Schedule 2, as the case may be, at the expiration of which thirty-day period
(a) the customers of such entity shall be entitled to Service as Roamers from
the other Party on the terms and conditions of this Agreement and (b) such
operating entity shall provide Service to customers of the other Party who are
Authorized Roamers, although the other Party is not obligated to request such
Service or to require its customers to request such Service. Notwithstanding the
foregoing, the other Party, in its reasonable discretion, may reject the
addition of any such Affiliate by delivering written notice thereof prior to the
expiration of the thirty-day period.

                                       3
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                                   ARTICLE III

                                     CHARGES
                                     -------

         Each Home Carrier whose customers (including the customers of its
resellers) receive Service from a Serving Carrier as Authorized Roamers under
this Agreement shall pay to the Serving Carrier who provided such Service one
hundred percent (100%) of the Serving Carrier's charges for CMRS and one hundred
percent (100%) of the toll charges set forth in Exhibit A. The amount of the
charges for the use of each Serving Carrier's Service are set forth in Exhibit A
attached to this Agreement.

                                   ARTICLE IV

                             EXCHANGE OF INFORMATION
                             -----------------------

         4.1   Exhibit B to this Agreement is a list furnished by the respective
Parties of the valid NPA/NXX combinations used by their respective customers.
These combinations shall be accepted by the other Party. Each NPA/NXX
combination is and shall be within the entire line range (0000-9999), or a
specified portion thereof. The minimum line range to be exchanged by the Parties
shall be 1,000 line numbers. Each Party shall be responsible for all billings
otherwise properly made under this Agreement to any number listed by such Party
within the range or ranges specified by it in Exhibit B. Additions, deletions,
or changes to NPA/NXX combinations and line number range(s) for the Home
Carrier's customers may be made upon at least fifteen (15) days prior written
notice to the Serving Carrier. Such notice shall be in the form attached as
Exhibit B to this Agreement and shall include the requested effective date for
the addition, deletion or change.

         4.2   Each Party shall provide to each other Party a list of MINs (from
among those within the NPA/NXX combination(s) identified pursuant to Section 4.1
hereof) and ESNs (of the telephones to which the other Party is not authorized
to provide Service pursuant to this Agreement), which shall be entered into the
Industry Negative File. The approved CIBERNET Negative File Guidelines, as
amended from time to time, shall be the governing criteria for the Parties.
Thereafter, from time to time, as agreed by the Parties, each Party shall notify
each other Party of all additions to, and deletions from, these lists for the
customers of that particular Party. Such notifications shall be made during
normal business hours of the Party being notified by facsimile or by telephone
with a written confirmation and shall be effective one (1) hour after receipt.

         4.3   Each Party hereby agrees to indemnify each and all of the other
Parties, together with their partners and any and all of their officers,
directors, employees, agents and/or affiliates, against, and hold them harmless
from, any and all claims, suits, demands, losses and expenses, including
reasonable attorneys' fees and disbursements, which may result in any way
whatsoever

                                       4
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from the indemnified Party's denial of Roamer or local Service to any NPA/NXX
and MIN combination which has been listed by the indemnifying Party as not being
authorized to receive Service; provided that (i) the person seeking
indemnification (the "Indemnified Person") provides notice of such claim
promptly after its discovery to the Party from which indemnification is sought
(the "Indemnifying Person") and in any event the Indemnifying Person will be
released from any obligation hereunder to the extent it is prejudiced by any
delay in the delivery of such notice, (ii) the Indemnifying Person shall have
the right to assume the defense of such claim, (iii) the Indemnified Person
shall provide such reasonable assistance and cooperation in the defense of such
claim as is requested by the Indemnifying Person, and (iv) the Indemnified
Person shall not settle or compromise any such claim without the prior written
consent of the Indemnifying Person.

         4.4   Each Party, due to system limitations, may purge or delete
numbers of its customers from the lists as referred to in Section 4.2 hereof,
but in all such cases, such purging or deletion must be done in accordance with
the approved CIBERNET Negative File Guidelines. If purging or deletion of
numbers is done prior to the time periods established by such Guidelines, or
through procedures not otherwise set forth, in the approved CIBERNET Negative
File Guidelines, the Party implementing the purge or deletion will assume
financial liability for any charges incurred by those numbers. All purges or
deletions made pursuant to this Section 4.4 shall be given through the Parties
and shall be in the form mutually agreed upon by the Parties and effective as of
the time established by the approved CIBERNET Negative File Guidelines (unless
otherwise modified by mutual agreement of the Parties.)

         4.5   Upon the implementation of wireless number portability in any
portion of either Party's system, the Parties shall cooperate in establishing an
alternative method for exchanging ESN, MIN, and NPA/NXX information required to
permit roaming by the other Party's customers in their respective systems.

                                    ARTICLE V

                                      FRAUD
                                      -----

         5.1   The Parties will cooperate and, as necessary, supplement this
Agreement in order to minimize fraudulent or other unauthorized use of their
systems. If any Party reasonably decides that, in its sole judgment, despite due
diligence and cooperation pursuant to the preceding sentence, fraudulent or
other unauthorized use has reached an unacceptable level of financial loss and
is not readily remediable, such Party may suspend the use of applicable NPA/NXX
combinations, in whole or in part, pursuant to the terms of this Agreement.

         5.2   Each Party shall take reasonable actions to control fraudulent
Roamer usage, including without limitation using either (i) a positive
validation/verification ("PV') system provided by a mutually agreed upon
validation/verification service under which the ESN, MIN and/or NPA/NXX used in
a call in the Serving Carrier's system is compared against a list of Authorized
Roamers or (ii) SS-7 connections through a network of carriers. The Parties
shall

                                       5
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work together in good faith to designate and implement a mutually agreeable PV
system and enhancements thereto or alternative systems. The Home Carrier shall
have no responsibility or liability for calls completed by a Serving Carrier
without obtaining positive validation/verification as required herein.

         5.3   In addition to other procedures set forth in this Agreement, a
Home Carrier may notify a Serving Carrier by facsimile, with written
confirmation, that certain NPA/NXX combinations are not to receive Service. Any
calls completed using such NPA/NXX combinations made one full business day or
more after such notice has been given shall be the sole responsibility of the
Serving Carrier and the Home Carrier shall not be charged any amount for such
calls.

         5.4   Each Serving Carrier shall use commercially reasonable efforts to
provide each Home Carrier with real-time visibility of call detail records
delivered through a network compatible with AT&T's network. Such information
shall be delivered within one hour of the applicable call. In the event that the
Serving Carrier provides such a real-time visibility system, the Serving Carrier
shall not be liable in any event for a temporary failure of the system unless
the Serving Carrier has been notified of such failure by the Home Carrier and
the Serving Carrier does not take commercially reasonable steps to remedy the
failure. If the Serving Carrier has been so notified and has so failed to take
such commercially reasonable steps, the Serving Carrier shall be liable for all
unauthorized usage attributed to Home Carrier's subscribers during the period
from the time Serving Carrier was notified of the problem to the time that the
problem has been resolved to the reasonable satisfaction of the Home Carrier.

         5.5   For purposes of notification under this Article V, the following
addresses and facsimile numbers shall be used:

                 If to AT&T:      AT&T Wireless Services, Inc.
                                  7277 164/th/ Avenue, N.E.,
                                  Redmond, Washington 98052
                                  Attn: Billing and ICS Operations

                 If to Company:   Holding Company
                                  1010 N. Glebe Road, Suite 800
                                  Arlington, VA  22201
                                  Attn: Product Development - Roaming
                                  Tel. No. 703-236-1100
                                  Fax No. 703-236-1100

Each Party may change the names, addresses and numbers set forth above by
providing notice to the other Party as provided in Article XIII below.

                                       6
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                                   ARTICLE VI

                                     BILLING
                                     -------

         6.1   Each Home Carrier shall be responsible for billing to, and
collecting from, its own customers all charges that are incurred by such
customers as a result of service provided to them as Authorized Roamers by the
Serving Carrier. The Home Carrier shall also be responsible for billing its
customers for, and remitting to, the Federal Government all federal excise tax
that may be due in connection with the service being billed by it to its
customers. While the Serving Carrier will be responsible for the computation and
remittance of all state and local taxes, each Home Carrier shall be liable to
the Serving Carrier for all such state and local taxes remitted by the Serving
Carrier, for Authorized Roamers regardless of whether these amounts are paid to
the Home Carrier by its customers.

         6.2   Each Serving Carrier who provides Service to an Authorized Roamer
pursuant to this Agreement shall forward Roamer billing information, within five
business days of the call date, in accordance with the procedures and standards
set forth in the CIBER Record to the Home Carrier's Authorized Receipt Point.
CIBER Type 50 and CIBER Type 70 records shall not be accepted without mutual
signed agreement and if such mutual agreement is reached it will be attached to
this Agreement. Any future revisions of the CIBER Record or additional record
types must be mutually agreed upon before implementation. In the event the
parties use the CIBERNET Net Settlement Program, or alternative settlement
program such information must be in a format in compliance with the CIBER Record
requirements or agreed upon format.

         6.3   Where the Authorized Roamer billing information required to be
provided by the Serving Carrier in accordance with Section 6.2 above is not in
accordance with the CIBER Record, the Home Carrier may return a record to the
Serving Carrier as provided in the CIBER Record. Returning the defective record
will be in accordance with CIBER Record established procedures. The Serving
Carrier may correct the defective record and return it to the Home Carrier for
billing, provided that the time period from the date of the Service call at
issue to the receipt of the corrected record does not exceed sixty (60) days.

         6.4   No credit for insufficient data or defective records shall be
permitted except as provided in Section 6.3 above, unless mutually agreed upon
by both Parties.

         6.5   Each Home Carrier may at its discretion perform any necessary
edits at its Clearinghouse on incollect or outcollect call records to ensure
compliance with the terms of this Agreement.

                                       7
<PAGE>

                                   ARTICLE VII

                                   SETTLEMENT
                                   ----------

         7.1   Each Party will settle its accounts with the other Parties on the
basis of billing information received as described in this Article VII. In the
event both Parties use a net financial settlement procedure, the Parties shall
not submit a paper invoice but will make payments in accordance with such net
financial settlement procedures provided that the Parties may submit call
records for payment that relate to calls made more than sixty (60) days from the
date of the call if such call was the subject of a dispute or investigation
regarding fraudulent or unauthorized use.

         7.2   If an incorrect roaming rate is charged by the Serving Carrier to
the Home Carrier, the Serving Carrier shall refund all amounts in excess of the
contract rate back to the Home Carrier within forty-five (45) days of
notification by the Home Carrier. Each carrier shall have ninety (90) days from
the end of the settlement period to invoice for amounts in excess of the
contract rate. The Home Carrier will send a collection letter within sixty (60)
days of the invoice date, within ninety (90) days of the invoice date, and
within one hundred (120) days of the invoice date. If the invoice remains unpaid
after one hundred twenty (120) days from the original invoice date, the Home
Carrier may withhold the amounts from the CIBERNET Net Settlement Program or
alternative settlement program.

         7.3   In the event that either Party does not use a net financial
settlement procedure, the billing and payment for charges incurred under this
Agreement shall be as set forth below.

               7.3.1  The parties shall determine amounts owed to each other
         for Service provided to Roamers in one-month periods with such period
         beginning on the sixteenth day of each calendar month and ending on the
         fifteenth day of the following month in which Service is provided. The
         end of this Period shall be referred to as "Close of Billing."

               7.3.2  The Parties shall send each other an invoice for
         Services used under this Agreement within fifteen (15) days after the
         Close of Billing.

               7.3.3  Each invoice shall contain the following information.

               (a)   Billing period used by Serving Carrier

               (b)   Batch sequence number

               (c)   Serving and Home Carrier System Identification Number

               (d)   Air Service charges

                                       8
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               (e)   Total toll charges (both intrastate and interstate)

               (f)   All other charges and credits

               (g)   Total taxes

               (h)   Total charges

               7.3.4  Payment on such invoices shall be made in the form of a
           check or a wire transfer which must be received by the invoicing
           party within thirty (30) days from the date of the invoice. Late
           payments shall be charged with a late payment fee of one and one half
           percent (1.5%) of the outstanding balance for each thirty-day period
           (or portion thereof) that such payments are late.

               7.3.5  Each Party may offset the amount owed to the other
         Party under this Agreement and a single payment of the balance to the
         Party entitled to receive such balance shall be made.

         7.4   If the Serving Carrier provides pre-call validation of the Home
Carrier's customers, the Home Carrier agrees to implement Negative File
Suppression at the Clearinghouse and the CIBERNET Negative File Guidelines and
procedures do not apply.

                                  ARTICLE VIII

                     AUTOMATIC CALL DELIVERY AND HAND-OFF
                     ------------------------------------

         8.1   Each Party shall, as Serving Carrier, provide for automatic call
delivery for customers of the other Party who are Roamers in the Serving
Carrier's system. To this end, each Party shall continuously provide the
hardware, software and transmission facilities required for such call delivery
either directly between the systems of the Parties or indirectly through a
separate network of wireless communications carriers. The hardware, software and
transmission facilities provided by each Party hereunder shall at all times be
operated and maintained to provide the most efficient level of service that is
technically feasible and commercially reasonable to minimize transmission errors
and Service interruptions.

         8.2   If the Parties have implemented linking facilities pursuant to
Section 8.3, the Serving Carrier shall automatically hand-off to the Home
Carrier, and as requested shall automatically accept hand-off from the Home
Carrier in order to provide Service as specified in Article II, calls to or from
a customer of the Home Carrier in accordance with the hand-off procedures
established for such linking facilities. To this end, each Party shall
continuously provide the hardware, software and transmission facilities required
for such call hand-off either directly between the systems of such Home and
Serving Carrier or indirectly through a separate network of wireless
communications carriers. The hardware, software and transmission facilities
provided by each Party hereunder shall at all times be operated and maintained
to provide the

                                       9
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most efficient level of service that is technically feasible and commercially
reasonable to minimize transmission errors and Service interruption.

         8.3   The Parties will work together to evaluate the economic advantage
of various switch linking options to interconnect and facilitate networking of
the Parties' respective systems as required by this Agreement. Should the
Parties agree to install and maintain linking facilities, the cost of the
linking facilities shall be allocated pursuant to the following provisions:

               8.3.1  AT&T and Company will each pay one-half of the equipment
         costs for the establishment of microwave facilities to link the
         Parties' respective systems for the purposes of automatic call delivery
         and automatic call hand-off. Each Party is solely responsible for the
         costs of preparing its own facilities for the system link.

               8.3.2  Equipment costs for the establishment of a landline link
         (T-1) to link the Parties' respective systems together for these
         purposes shall be split between the Parties as follows:

               (a)    AT&T and Company shall each pay one-half of the cost for
           the installation, use, modification, or discontinuance of the linking
           facilities. Each Party is solely responsible for all costs to prepare
           its own facilities for the link between the systems.

               (b)    For ease of administration, AT&T will order and be the
           customer of record ("COR") for such facilities. Company will
           reimburse AT&T monthly for its share of the recurring costs of such
           facilities. The COR shall be responsible for invoicing the other
           Party for its share of the costs, with payment due within 30 days of
           receipt of the invoice.

               8.3.3  The Parties agree that this Section 8.3 relates only to
         those costs necessary to establish the referenced facilities. This
         section is not applicable to the allocation of costs with respect to
         the provision of Service for each Parties' customers.

         8.4   The Parties acknowledge that they do not currently have the
technical systems in place to allocate charges for cellular service provided by
a Carrier when a customer's call is handed off from one system to another. The
Parties agree that the revenues and costs for a call belong to the Party whose
system operates the originating cell site (the "Bill and Keep System").

                                   ARTICLE IX

                 TERM, TERMINATION, AND SUSPENSION OF AGREEMENT
                 ----------------------------------------------

         9.1   This Agreement shall have a term commencing on the date first
written above and continuing for a period of 20 years. Thereafter, this
Agreement shall renew automatically on a

                                      10
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year-to-year basis unless either party terminates the Agreement by written
notice to the other party given at least 90 days prior to the conclusion of the
original or any subsequent term. After ten years, the Agreement may be
terminated by either party at any time upon 90 days prior written notice.

         9.2   This Agreement may be terminated or suspended by either Party
immediately upon written notice to the other of a Default (as defined in Section
10.1) by the other Party. In addition, either Party may suspend this Agreement
immediately upon written notice to the other Party of the existence of a breach
of this Agreement, whether or not such breach constitutes a Default, which
materially affects the Service being provided to Customers of the non-breaching
Party. While any suspension of this Agreement, whether in part or in whole, is
in effect, the Parties shall work together to resolve as expeditiously as
possible the difficulty that caused the suspension. At such time as the Party
originally giving notice of suspension concludes that the problem causing the
suspension has been resolved, that Party shall give to the other written notice
to this effect. This Agreement shall resume in full effect within five (5)
business days after the Parties have mutually agreed that the problem has been
resolved.

         9.3   The Parties shall cooperate to limit the extent and effect of any
suspension of this Agreement to what is reasonably required to address the cause
of the suspension.

         9.4   In the event that a Party transfers control of an Affiliate
listed in Schedule 1 or Schedule 2, as the case may be, the Party shall provide
at least four (4) months' prior written notice to the other Party and upon such
transfer such Affiliate shall be deleted from the appropriate Schedule.

         The termination or suspension of this Agreement shall not affect the
rights and liabilities of the Parties under this Agreement with respect to all
Authorized Roamer charges incurred prior to the effective date of such
termination or suspension.

                                    ARTICLE X

                                     DEFAULT
                                     -------

         10.1   A Party will be in "Default" under this Agreement upon the
occurrence of any of the following events:

                10.1.1  Material breach of any material term of this Agreement,
         if such breach shall continue for thirty (30) days after receipt of
         written notice thereof from the nonbreaching Party;

                10.1.2  Voluntary liquidation or dissolution or the approval by
         the management or owners of a Party of any plan or arrangement for the
         voluntary liquidation or dissolution of the Party;

                                      11
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                10.1.3  A final order by the Federal Communications Commission
         ("FCC") revoking or denying renewal of CMRS licenses or permits granted
         to such Party which, individually or in the aggregate, are material to
         the business of such Party; or

                10.1.4  Such Party (i) filing pursuant to a statute of the
         United States or of any state, a petition for bankruptcy or insolvency
         or for reorganization or for the appointment of a receiver or trustee
         for all or a portion of such Party's property, (ii) has filed against
         it, pursuant to a statute of the United States or of any state, a
         petition for bankruptcy or insolvency or for reorganization or for the
         appointment of a receiver or trustee for all or a portion of such
         Party's property, provided that within sixty (60) days after the filing
         of any such petition such Party fails to obtain a discharge thereof, or
         (iii) making an assignment for the benefit of creditors or petitioning
         for, or voluntarily entering into, an arrangement of similar nature,
         and provided that such filing, petition, or appointment is still
         continuing.

         10.2   All claims and disputes relating in any way to the performance,
interpretation, validity, or breach of this Agreement, including but not limited
to a claim based on or arising from an alleged tort, shall be resolved as
provided in this Section 10.2. It is the intent of the Parties that any
disagreements be resolved amicably to the greatest extent possible.

                10.2.1  If a disagreement cannot be resolved by the
         representatives of the Parties with day-to-day responsibility for this
         Agreement, such matter shall be referred to an executive officer of
         each of the Parties. The executive officers shall conduct face-to-face
         negotiations at a neutral location or such other location as shall be
         mutually agreed upon. If these representatives are unable to resolve
         the dispute within ten business days after either Party requests the
         involvement of the executive officers, then either Party may, but is
         not required to, refer the matter to mediation or arbitration, as
         applicable in accordance with Sections 10.2.2 and 10.2.3.

                10.2.2  In any case where the amount claimed or at issue is
         Five Hundred Thousand Dollars ($500,000) or more and the Parties are
         unsuccessful in resolving the disagreement, the Parties agree to submit
         the disagreement to non-binding mediation upon written notification by
         either Party. The Parties shall mutually select an independent mediator
         experienced in telecommunications system disputes. The specific format
         for the mediation shall be left to the discretion of the mediator. If
         mediation does not result in resolution of the disagreement within
         thirty days of the initial request for mediation, then either Party
         may, but is not required to, refer the matter to arbitration.

                10.2.3  Any disagreement not finally resolved in accordance
         with the foregoing provisions of this Section 10.2 shall, upon written
         notice by either Party to the other, be resolved by final and binding
         arbitration. Subject to this Section 10.2.3, such arbitration shall be
         conducted through, and in accordance with the rules of, JAMS/Endispute.
         A single neutral arbitrator shall decide all disputes. Each Party shall
         bear its own expense with respect to the arbitration, except that the
         costs of arbitration proceeding itself, including the fees and expenses
         of the arbitrator, shall be shared equally by the Parties.

                                      12
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         The arbitration shall take place in a neutral location selected by the
         arbitrator. The arbitrator may permit discovery to the full extent
         permitted by the Federal Rules of Civil Procedure or to such lesser
         extent as the arbitrator determines is reasonable. The arbitrator shall
         be bound by and strictly enforce the terms of this Agreement. The
         arbitrator shall make a good faith effort to apply applicable law, but
         an arbitration decision and award shall not be subject to review
         because of errors of law. The arbitrator shall have the sole authority
         to resolve issues of the arbitrability of any disagreement, including
         the applicability or running of any applicable statute of limitation.
         The arbitrator shall not have power to award damages in connection with
         any dispute in excess of actual compensatory damages nor to award
         punitive damages nor any damages that are excluded under this Agreement
         and each party irrevocably waives any claim thereto. The award of any
         arbitration shall be final, conclusive and binding on the Parties.
         Judgment on the award may be entered in any court having jurisdiction
         over the Party against which the award was made. Nothing contained in
         this Section 10.2.3 shall be deemed to prevent either party from
         seeking any interim equitable relief, such as a preliminary injunction
         or temporary restraining order, pending the results of the arbitration.
         The United States Arbitration Act and federal arbitration law shall
         govern the interpretation, enforcement, and proceedings pursuant to the
         arbitration clause in this Agreement.

                                   ARTICLE XI

                             SUCCESSORS AND ASSIGNS
                             ----------------------

         11.1  Neither Party may, directly or indirectly, sell, assign,
transfer, or convey its interest in this Agreement or any of its rights or
obligations hereunder, including any assignment or transfer occurring by
operation of law, without the written consent of both Parties, except that (i)
either Party may assign or delegate this Agreement or any of its rights or
obligations hereunder to an Affiliate of such Party without the consent of the
other Party, but such assignment or delegation will not relieve the Party of any
of its obligations hereunder and (ii) a Party may assign its rights and
obligations hereunder to an assignee of its Service license or permit issued by
the FCC, provided that such assignee expressly assumes, by written instrument
approved by the other Party, all of the obligations of such Party hereunder and
thereby becomes a Party hereunder. In no event will an assignment permitted
under this Section 11.1 without the consent of the other Party obligate a
Serving Carrier to provide Service to any customers of the assignee or any of
its Affiliates other than customers residing in the area in which the assignor
previously was licensed to provide Service.

         11.2  No person other than a Party to this Agreement shall acquire any
rights hereunder as a third-party beneficiary or otherwise by virtue of this
Agreement.

                                  ARTICLE XII

                                      13
<PAGE>

               NO PARTNERSHIP OR AGENCY RELATIONSHIP IS CREATED
               ------------------------------------------------

         Nothing contained in this Agreement shall constitute the Parties as
partners with one another or render any Party liable for any debts or
obligations of any other Party, nor shall any Party hereby be constituted the
agent of any other Party.

                                 ARTICLE XIII

                    NOTICES AND AUTHORIZED REPRESENTATIVES
                    --------------------------------------

         Unless otherwise provided herein, any notice, request, instruction or
other document to be given hereunder by any Party to the other shall be in
writing and delivered by hand delivery, certified mail (postage prepaid, return
receipt requested), facsimile, or overnight air delivery service, as follows:

                    If to AT&T, to:     AT&T Wireless Services, Inc.
                                        7277 164th Avenue, N.E.,
                                        Redmond, Washington 98052
                                        Attn: Intercarrier Services

                    with a copy to:     AT&T Wireless Services, Inc.
                                        7277 164th Avenue, N.E.,
                                        Redmond, Washington 98052
                                        Attn: Legal Department

                    If to Company, to:  Holding Company
                                        1010 N. Glebe Road, Suite 800
                                        Arlington, VA 22201
                                        Attn: Product Development--Roaming

                    with a copy to:     Holding Company
                                        1010 N. Glebe Road, Suite 800
                                        Arlington, VA 22201
                                        Attn: Legal Department

or such other address as any Party may from time to time furnish to the other
Party by a notice given in accordance with the terms of this Section. All such
notices and communications shall be deemed to have been duly given at the time
delivered by hand, if personally delivered; three business days after being
deposited in the mail, if mailed; subject to confirmation of receipt, on the
date of receipt if received by 3:00 p.m., local time, on any business day and
otherwise on the next business day, if by facsimile; and the next business day,
if sent by overnight air delivery service.

                                       14
<PAGE>

                                  ARTICLE XIV

                                CONFIDENTIALITY
                                ---------------

         14.1  Each Party shall, and shall cause each of its Affiliates and each
of its and their employees, agents, and contractors, to keep confidential and
not use for any purpose, except as contemplated by this Agreement, any and all
information and know-how provided to it by the other Party which is identified
in writing as confidential ("Confidential Information"). Identification of
information as confidential shall, in the case of information delivered in
tangible form, appear on at least the face or first page of such information
and, in the case of information communicated verbally, be given verbally
contemporaneously with the delivery of the information and confirmed in writing
within five business days thereafter. Notwithstanding the foregoing, the
following information shall be treated as Confidential Information without any
further identification as such: (i) The terms, but not including the mere
existence, of this Agreement; and (ii) all information exchanged pursuant to
Article IV.

         14.2  Notwithstanding Section 14.1, a Party shall have no obligation to
keep confidential any information that (a) was rightfully in the receiving
Party's possession before receipt from the disclosing Party, (b) is or becomes a
matter of public knowledge without violation of this Agreement by the receiving
Party, (c) is received by the receiving Party from a third party in possession
of and, to the best of the receiving Party's knowledge, with a right to make an
unrestricted disclosure of such information, (d) is disclosed by the disclosing
Party to a third party without imposing a duty of confidentiality on the third
party, or (e) is independently developed by the receiving Party without the use
of any Confidential Information. In addition, a Party may disclose any
Confidential Information to the extent required by applicable law or regulation
or by order of a court or governmental agency; provided, that prior to
disclosure the Party shall use all reasonable efforts to notify the other Party
of such pending disclosure and shall provide any reasonable assistance requested
by the other Party to maintain the confidentiality of the information.

         14.3  The Parties agree that a Party will not have an adequate remedy
at law in the event of a disclosure or threatened disclosure of Confidential
Information in violation of this Article XIV. Accordingly, in such event, in
addition to any other remedies available at law or in equity, a Party shall be
entitled to specific enforcement of this Article XIV and to other injunctive and
equitable remedies against such breach without the posting of any bond.

         14.4  The obligations under this Article XIV shall survive the
termination of this Agreement for a period of three years.

                                  ARTICLE XV

                                 MISCELLANEOUS
                                 -------------

                                       15
<PAGE>

         15.1  The Parties agree to comply with, conform to, and abide by all
applicable and valid laws, regulations, rules and orders of all governmental
agencies and authorities, and agree that this Agreement is subject to such laws,
regulations, rules and orders. All references in this Agreement to such laws,
regulations, rules and orders include any successor provision. If any amendment
to or replacement of the same materially alters the benefits, fights, and duties
of the Parties hereunder, the Parties agree to negotiate in good faith an
amendment to this Agreement to restore the respective positions of the Parties
to substantially the same point as existed prior to such amendment or
replacement.

         15.2  The Parties agree to use their respective best, diligent, and
good faith efforts to fulfill all of their obligations under this Agreement. The
Parties recognize, however, that to effectuate all the purposes of this
Agreement, it may be necessary either to enter into future agreements or to
amend this Agreement, or both. In that event, the Parties agree to negotiate
with each other in good faith.

         15.3  This Agreement constitutes the full and complete agreement of the
Parties. Any prior agreements among the Parties with respect to this subject
matter are hereby superseded. This Agreement may not be amended, except by the
written consent of the Parties. Waiver of any breach of any provision of the
Agreement must be in writing signed by the Party waiving such breach or
provision and such waiver shall not be deemed to be a waiver of any preceding or
succeeding breach of the same or any other provision. The failure of a Party to
insist upon strict performance of any provision of this Agreement or any
obligation under this Agreement shall not be a waiver of such Party's right to
demand strict compliance therewith in the future.

         15.4  The headings in this Agreement are inserted for convenience and
identification only and are not intended to describe, interpret, define or limit
the scope, extent or intent of this Agreement or any provision thereof.

         15.5  This Agreement may be executed in counterparts, each of which
shall be deemed an original, but all of which together shall constitute one and
the same Agreement.

         15.6  This Agreement shall be construed in accordance with the laws of
the state of Washington without reference to the choice of law principles,
except as subject to the United States Arbitration Act and the Federal
Communications Act, each as amended.

         15.7  Neither Party shall be liable to the other Party for any special,
indirect, consequential or punitive damages.

         15.8  The Parties agree that they will not use the name, service marks
or trademarks of the other party or any of its Affiliates in any advertising,
publicity releases or sales presentations, without such Party's written consent.
Neither Party is licensed hereunder to conduct business under any logo,
trademark, service or trade name (or any derivative thereof) of the other Party.

         15.9  Neither of the Parties will be liable for nonperformance or
defective performance of its obligations under this Agreement to the extent and
for such periods of time as such

                                       16
<PAGE>

nonperformance or defective performance is due to reasons outside such Party's
control, including, without limitation, acts of God, war, acts of any
governmental authority, riots, revolutions, fire, floods, explosions, sabotage,
nuclear incidents, lightning, weather, earthquakes, storms, sinkholes,
epidemics, strikes, or delays of suppliers or subcontractors for the same
causes. Neither Party shall be required to settle any labor dispute or other
third party dispute in any manner which is deemed by that Party to be less than
totally advantageous, in that Party's sole discretion.

         15.10 This Agreement is a non-exclusive arrangement between the
Parties. Nothing contained in this Agreement is intended or should be construed
to preclude or limit a Party from obtaining from or providing to a third party
Service of a type available or required to be provided under this Agreement.

                                       17
<PAGE>

           EXECUTED as of the date first written above.

                                           AT&T WIRELESS SERVICES, INC

                                           By:  ______________________________
                                           Name:
                                           Title:

                                           HOLDING COMPANY

                                           By: _______________________________
                                           Name:
                                           Title:

                                       18
<PAGE>

                                   EXHIBIT A

                                SERVICE CHARGES

[To be updated and provided at Closing]

Airtime Rates:
--------------
[AWS Boston (including Rockingham, Stafford Counties NH, Hyannis, MA.,
Manchester, NH. and Worcester, MA)

7/17/1998 through 7/16/1999             $0.10 per minute or partial minute.
7/17/1999 through the remaining term of this Agreement:

TeleCorp and AWS agree that the airtime rates charged between the parties shall
be the lower of (a) the actual AWS average retail rate charged by AWS to its
Boston customers roaming into TeleCorp markets located within the Boston MTA
(but not less than the actual AWS average retail rate charged by AWS to its
Boston customers in the AWS Boston Market) or (b) $0.10 per minute.]

AWS and remaining Company BTA's

7/17/1998 through 12/31/1999            $0.25 per minute or partial minute.
1/1/2000 through 12/31/2000             $0.20 per minute or partial minute.
1/1/2001 through 12/31/2001             $0.15 per minute or partial minute.
1/1/2002 through 12/31/2002             $0.10 per minute or partial minute.

1/1/2003 through the remaining term of this Agreement

The Company and AWS agree that the airtime rates charged between the parties
shall be the lower of (a) the actual AWS average retail rates charged by AWS to
its customers roaming into TeleCorp markets (but not less than the actual AWS
average retail rate charged by AWS to its customers) or (b) $0.10 per minute.

Neither Party will charge for incomplete calls, busy calls, 611 calls, feature
activations or interconnect fees. Airtime rates are charged in full minute
increments with each partial minute rounded to the next full minute.

Toll Rates:
-----------
$0.05 per InterLata minute and $0.02 per IntraLata minute.

International toll rates shall be no more than AT&T tariff rates.

                                      19
<PAGE>

TeleCorp, Inc. and AWS agree to offer a toll free calling area within their
respective cellular areas which reasonably approximates, or is larger than, the
toll free area offered by the landline telephone company in the area.

Default rates apply to markets managed by AT&T Wireless Services on behalf of
other carriers as shown on Schedule 1.

                                      20

<PAGE>

                                   EXHIBIT B

                                Technical Data

[To be updated and provided at Closing]

The following information is furnished by __________ to __________ pursuant to
Section 4.1 of the Intercarrier Roamer Service Agreement between AT&T Wireless
Services, Inc. and _______________________, by _______________________:

NPA/NXX         LINE RANGE            SID/BID               CITY START DATE
END DATE

By:________________________

Title:_____________________

Issue Date:________________

The effective date shall be

                                      21<PAGE>

                                                                   Exhibit 10.21

                    ROAMING ADMINISTRATION SERVICE AGREEMENT

         ROAMING ADMINISTRATION SERVICE AGREEMENT ("Agreement") made this
_________________, 2000, by and between AT&T Wireless Services, Inc. ("AWS"), a
Delaware corporation, with its principal place of business at 5000 Carillon
Point, Kirkland, WA 98033, and Holding Company ("Holding Company"), a Delaware
corporation, with its principal place of business at 1010 N. Glebe Road,
Arlington, VA 22201.

                                    Recitals
                                    --------

         WHEREAS, Holding Company and its Affiliates (collectively, the
"Company") would like to receive certain benefits under Intercarrier Roaming
Services Agreements between AWS and other providers of wireless
telecommunications service, and AWS would like Company to receive such benefits
under the terms and conditions of this Agreement:

         WHEREAS, AWS provides Roamer Administration Services to owners and
operators of wireless telecommunications systems;

         WHEREAS, the Company owns and operates wireless telecommunications
system(s) identified on Exhibit A and would like to receive Roamer
Administration Services from AWS; and

         WHEREAS, AWS would like to provide the Company with Roamer
Administration Services subject to the terms and conditions of this Agreement;

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
contained herein, and other good and valuable consideration, the parties hereby
agree as follows:

                                   Definitions

           As used herein, the following terms shall have the following
meanings:

         AS means the Administrative Services as more fully described in Exhibit
         --
B.

         CIBER means Cellular Intercarrier Billing Exchange Record as more fully
         -----
described in the CIBER Standard.

         CIBER Standard means the publication prepared by CIBERNET Corporation,
         --------------
a wholly-owned subsidiary of the Cellular Telecommunications Industry
Association, as a service to the wireless communications industry. Unless
specifically provided otherwise in this Agreement, all words and phrases defined
in the CIBER Standard shall have the meaning herein that they have therein.

         Claims means any claims, liabilities, damages, costs and expenses
         ------
(including reasonable attorneys' fees) asserted by a third party against a party
to this Agreement.
<PAGE>

         CMRS or Service means Commercial Mobile Radio Service.
         ---------------

         EDS PCC means EDS Personal Communications Corporation.
         -------

         EDS PCC Agreement means that certain Interoperator Agreement dated
         -----------------
January 3, 1997, between AWS and

         EDS PCC for certain services, as that Agreement may be amended,
         -------
extended or renegotiated from time to time.

         ESN means the Electronic Serial Number that is encoded in a wireless
         ---
telephone set by the manufacturer and which is broadcast by such telephone.

         Expenses means those costs and expenses related to providing the
         --------
Roaming Administration Services set forth in Exhibit C, as may be amended from
time to time by AWS.

         Fees means those fees for Roaming Administration Services set forth in
         ----
Exhibit C, as may be amended from time to time by AWS.

         Incollect Obligations means those obligations of the Company to AWS and
         ---------------------
Other Wireless Carriers that arise from Roaming by the Company's subscribers on
other wireless systems. These Incollect Obligations accrue separate for each of
AWS and each Other Wireless Carrier.

         Intercarrier Roaming Services Agreement means an agreement entered into
         ---------------------------------------
by two facilities-based providers of CMRS under which each carrier agrees to
provide Service to the subscribers of the other carrier and which sets forth
other terms and conditions of the provision of such Service, including but not
limited to price, payment or settlement, and fraud liability terms, as the
agreement may be amended, extended or renegotiated from time to time.

         ISS means Intercarrier Settlement Services as more fully described in
         ---
Exhibit B.

         MIN means the ten-digit Mobile Identification Number which is assigned
         ---
by a Home Carrier to each of its registered customers.

         NACN means the North American Cellular Network, Inc. and the SS7
         ----
signaling network owned and operated by the North American Cellular Network,
Inc.

         NPA/NXX combinations means the six-digit numerical combinations
         -------
assigned by regulatory authorities to identify the area code and telephone
number prefix for Service.

         NSS means Net Settlement Services as more fully described in Exhibit B.
         ---

                                       2
<PAGE>

         Other Wireless Carriers means facilities-based providers of CMRS with
         -----------------------
whom AWS has entered an Intercarrier Roaming Services Agreement and which are
listed on Exhibit A-1.

         Outcollect Obligations means obligations owed to the Company by AWS and
         ----------------------
Other Wireless Carriers arising from Roaming by the subscribers of these
companies on the Company System. These Outcollect Obligations accrue separately
for each of AWS and each Other Wireless Carrier.

         PRV means Positive Roamer Verification services as more fully described
         ---
in Exhibit B.

         Roamer means a customer of a wireless carrier who seeks Service within
         ------
a geographic area served by another wireless carrier.

         Roaming Administrative Services means the services described in Exhibit
         -------------------------------
B, including AS, FV, ISS, NSS, PRV and XLI, together with the services that may
be provided in connection with the access to the Intercarrier Roaming Services
Agreements entered into between AWS and Other Wireless Carriers.

         Serving Carrier means a Party who provides Service for registered
         ---------------
customers of another Party while such customers are in the geographic area where
the Serving Carrier, directly or through subsidiaries, provides Service.

         Settlement Period shall mean each one-month period of time commencing
         -----------------
at 12:01 a.m. Pacific Standard Time on the sixteenth day of a given calendar
month and ending at 12:00 midnight on the fifteenth day of the immediately
following calendar month.

         XLI means a certain type of PRV service as more fully described in
         ---
Exhibit B.

         Company System means the wireless telecommunications system(s) owned
         --------------
and operated by the Company as identified on Exhibit A.

                                       3
<PAGE>

                                   Agreement

     1.   Access to Intercarrier Roaming Services Agreements. During the term
          --------------------------------------------------
of this Agreement, AWS will make available to Company the benefits of the
Intercarrier Roaming Services Agreements between AWS and Other Wireless Carriers
listed on Exhibit A-1, subject to the consent of such Other Wireless Carriers
and subject to the Company being a member in good standing of the NACN. The
Company will permit the subscribers of such Other Wireless Carriers to use the
facilities of the Company under the terms and conditions of the applicable
Intercarrier Roaming Services Agreements. AWS may amend Exhibit A-1 by adding
Other Wireless Carriers who have agreed to extend an Intercarrier Roaming
Services Agreement to the Company or by deleting Other Wireless Carriers who
have either revoked the consent to extend an Intercarrier Roaming Services
Agreement to the Company or with whom the Intercarrier Roaming Services
Agreement has terminated or expired, any such amendment to be effective no
earlier than 7 days after the date such notice is given.

     1.1  AWS Authority and Separate Rate Agreements. The Company agrees that
          ------------------------------------------
AWS has full authority to negotiate terms, amendments of and addenda to the
Intercarrier Roaming Services Agreements, administer the Intercarrier Roaming
Services Agreements and settle disputes under the Intercarrier Roaming Services
Agreements on behalf of the Company and that the Company will be bound by and
comply with such terms, amendments, addenda, administrative decisions and
settlements. The Company may, at its option, choose to negotiate a separate rate
for roaming Service with any or all of the Other Wireless Carriers. In order to
have these separate rates included within the Roamer Administration Services,
the Company must provide AWS with written documentation verifying the rates at
least thirty (30) days prior to the effective date for such rates.

     1.2  Separate Liability. The Company is liable for all of its obligations
          ------------------
under each Intercarrier Roaming Services Agreement in which it participates,
including but not limited to payment obligations and fraud liability
obligations. AWS will make available a copy of applicable Intercarrier Roaming
Services Agreements within 30 days of request by the Company.

     1.3  Effect of Intercarrier Roaming Services Agreements. Each Intercarrier
          --------------------------------------------------
Roaming Services Agreement, as may be amended with respect to the Company under
section 1.1 above, supplies the terms and conditions of roaming services with
respect to each Other Wireless Carrier. AWS maintains full control to continue
or to terminate or let expire any Intercarrier Roaming Services Agreement.
Nothing in this Agreement obligates AWS to enter into or to continue any
Intercarrier Roaming Services Agreement with any Other Wireless Carrier. AWS
will notify the Company no less than thirty (30) days in advance of any
termination by AWS or expiration of any Intercarrier Roaming Services Agreement.

     1.4  Fraud Control. The Company shall take reasonable actions to control
          -------------
fraudulent Roamer usage when acting as a Serving Carrier to be consistent with
the Intercarrier Roaming Services Agreements, including without limitation using
SS-7 connections through the NACN which perform validation functions. The
Company shall use commercially reasonable efforts to provide each Other Wireless
Carrier with real-time visibility of call detail records delivered

                                       4
<PAGE>

through a network compatible with AT&T's network. Such information shall be
delivered within one hour of the applicable call. In the event that the Company
provides such a real-time visibility system, the Company shall not be liable in
any event for a temporary failure of the system unless the Company has been
notified of such failure by the Other Wireless Carrier and the Company does not
take commercially reasonable steps to remedy the failure. If the Company has
been so notified and has so failed to take such commercially reasonable steps,
the Company shall be liable for all unauthorized usage attributed to the Other
Wireless Carrier's subscribers during the period from the time the Company was
notified of the problem to the time that the problem has been resolved to the
reasonable satisfaction of the Other Wireless Carrier.

     1.5  Allocation of Roamer Revenues and Roamer Expenses. AWS will treat the
          -------------------------------------------------
Company as an affiliate of AWS for administrative purposes in collecting and
paying amounts owed to the Company and owed by the Company under the applicable
Intercarrier Roaming Services Agreement. The Company acknowledges and agrees
that amounts owed to the Company from Other Wireless Carriers will be collected
by AWS, intermingled with other funds owed to AWS and then distributed to the
Company based upon the amounts owed to the Company for Roamer usage by
subscribers of the Other Wireless Carriers. The Company further acknowledges and
agrees that AWS will make payments for the Company to Other Wireless Carriers
based on the reports of Roamer usage by subscribers of the Compay on the systems
of the Other Wireless Carriers. AWS will recover these amounts through the NSS
functions described in Exhibit B.

     2.   Roaming Administration Services. During the term of this Agreement,
          -------------------------------
AWS hereby agrees to make available Roaming Administration Services to the
Company, subject to the terms of this Agreement. The Roaming Administration
Services are set forth in Exhibit B, which may be amended by AWS from time to
time upon written notice to the Company.

     2.1  Effect of EDS PCC Agreement. The Company acknowledges that AWS
          ---------------------------
receives certain of the Roaming Administration Services under the EDS PCC
Agreement. In the event the EDS PCC Agreement terminates or expires, AWS'
obligations to provide such Roaming Administration Services will cease. AWS will
give the Company notice promptly following its receipt of notice of termination
from EDS PCC and will give prior notice of any cessation of Roaming
Administration Services under this section 2.1. AWS will offer to resume such
services (on such terms as it determines at the time of such offer) in the event
that it extends or continues with EDS PCC, or enters into a new agreement with
any other provider, with respect to such services. Nothing in this Agreement
obligates AWS to extend, continue or enter into a new EDS PCC Agreement. The
Company agrees to comply with reasonable requests made by AWS in order to comply
with and administer the EDS PCC Agreement.

     2.2  Rates for Service. The Company shall pay AWS Fees and Expenses for the
          -----------------
Roamer Administration Services as set forth on Exhibit C attached hereto. AWS
may modify the Fees and Expenses set forth in Exhibit C upon thirty (30) days
prior written notice to the Company. Amounts owed each month for Fees and
Expenses will be included as amounts owed to AWS in the NSS function described
in Exhibit B.

                                       5
<PAGE>

     3.   Taxes. Unless the Company provides a certificate of exemption or other
          -----
evidence acceptable to appropriate taxing authorities, the Company shall pay any
applicable federal, state or local sales, use, public utility, gross receipts or
other taxes, fees or charges imposed on AWS as a result of (a) the roaming
services received by the Company under the Intercarrier Roaming Services
Agreements and (b) providing the Roaming Administration Services to the Company.
Such taxes will be included in bills when imposed or required by law and shall
be paid by the Company in accordance with this Agreement.

     4.   Payment of Net Amounts.
          ----------------------

     4.1  Amounts Owed to AWS. The Company will pay AWS in full any amounts owed
          -------------------
to AWS after the NSS procedure described in Exhibit B has occurred, including
amounts owed to AWS or Other Wireless Carriers, on or before the fifteenth day
of the month immediately following the close of a Settlement Period, provided
the Company has received the bill for such amounts at least five (5) business
days prior to such payment date. If the Company receives the bill later than
such time, the Company shall pay the bill within ten (10) days of its receipt by
the Company. Payments will be submitted to: AT&T Wireless Services, Inc., 7277
164/th/ Avenue, N.E., Redmond, Washington 98052 ATTN: Billing and Intercarrier
Settlement Services.

     4.2  Amounts Owed to the Company. AWS will pay the Company in full any
          ---------------------------
undisputed amounts owed to TeleCorp after the NSS procedure described in Exhibit
B has occurred by AWS or Other Wireless Carriers, (a) for amounts owed by AWS,
on or before the fifteenth day of the month immediately following the close of a
Settlement Period, (b) for amounts owed by Other Wireless Carriers, together
with the net settlement for the month following the date AWS receives payment
from the Other Wireless Carriers. Payments will be submitted to: Holding
Company, 1010 N. Glebe Road, Arlington, VA 22201, ATTN: Controller.

     4.3  Time. The Company acknowledges and understands that, AWS will pay
          ----
Other Wireless Carriers for the Company subscribers' roaming usage prior to
receiving payment from the Company. Accordingly, the Company acknowledges and
agrees that time is of the essence and will make timely payments to AWS of all
amounts set forth in each bill after the NSS procedures described in Exhibit B
have occurred. The Company is strictly liable to make timely payments hereunder,
and such liability is not relieved by any dispute that the Company may have with
AWS, Other Wireless Carriers or any other third party.

     4.4  Late Payment. If either party fails to make any payment to the other
          ------------
party when due hereunder, interest shall be paid, from the date due until paid
in full, at a rate of 1.5% per month or portion thereof. In no event shall
interest hereunder accrue at a rate that is in excess of the maximum rate
permitted by applicable law.

     5.   Compatibility with AWS Systems. AWS will establish and, from time to
          ------------------------------
time, enhance the systems that provide information used in performing functions
related to either the EDS PCC Agreement or Intercarrier Roaming Services
Agreements, including, but not limited

                                       6
<PAGE>

to, enhancements to billing systems. The Company will maintain compatibility
with these systems and system enhancements, including but not limited to the
CIBER format for billing records. The Company will be responsible for the costs
and expenses it incurs in maintaining this compatibility.

     6.   Indemnification. The Company will defend, indemnify and hold AWS,
          ---------------
its parent, subsidiaries and affiliates, and the officers, directors, employees
and representatives of each of them harmless from and against any Claims arising
from or made in connection with (a) any access or use (or inability to access or
use) of roaming Service by the Company or any subscriber of the Company, on the
system of AWS or any Other Wireless Carrier, (b) any access or use (or inability
to access or use) of roaming Service on the Company's wireless system by AWS or
an Other Wireless Carrier or a subscriber of AWS or an Other Wireless Carrier,
(c) any information provided by the Company to AWS, including without limitation
any rate information and suspected fraud information, (d) any unlawful,
negligent or otherwise wrongful act or failure to act of the Company or its
representatives, (e) a breach by the Company of any provision of this Agreement,
or (f) a breach by the Company of any obligation to or agreement with its
subscribers.

     7.   Limitation of Liability.
          -----------------------

     7.1  AWS SHALL NOT BE RESPONSIBLE TO THE COMPANY FOR ANY INDIRECT,
INCIDENTAL, CONSEQUENTIAL OR SPECIAL DAMAGES ARISING OUT OF OR IN CONNECTION
WITH AWS' PERFORMANCE UNDER THIS AGREEMENT, INCLUDING WITHOUT LIMITATION, ANY
DAMAGE TO OR LOSS OF REVENUES, BUSINESS OR GOODWILL. FURTHER, THE COMPANY
ACKNOWLEDGES THAT IN PERFORMING ITS OBLIGATIONS HEREUNDER AWS WILL RELY UPON
INFORMATION AND REPORTS PROVIDED TO AWS BY THIRD PARTIES. THE COMPANY AGREES
THAT AWS MAY RELY UPON SUCH INFORMATION IN PERFORMING ITS OBLIGATIONS HEREUNDER,
AND AWS SHALL NOT BE RESPONSIBLE OR LIABLE FOR THE ACCURACY OF ANY INFORMATION
IT RECEIVES FROM THIRD PARTIES IN PERFORMING ITS OBLIGATIONS UNDER THIS
AGREEMENT. IN NO EVENT WILL AWS' LIABILITY TO THE COMPANY, IN THE AGGREGATE,
EXCEED THE AMOUNT PAID IN FEES BY TELECORP UNDER THIS AGREEMENT DURING THE FIRST
TWELVE-MONTH PERIOD OF THE TERM OF THIS AGREEMENT. THIS SECTION 7.1 WILL SURVIVE
THE TERMINATION OR EXPIRATION OF THIS AGREEMENT.

     7.2  Neither of the parties will be liable for nonperformance or defective
or late performance of any of its obligations under this Agreement to the extent
and for such periods of time as such nonperformance, defective performance is
due to reasons outside such party's control, including, without limitation, acts
of God, war, acts (including failure to act) of any governmental authority,
riots, revolutions, fire, floods, explosions, sabotage, nuclear incidents,
lightning, weather, earthquakes, storms, sinkholes, epidemics, strikes or delays
of suppliers, subcontractors, Other Wireless Carriers or EDS PCC. Neither party
shall be required to settle any

                                       7
<PAGE>

labor dispute in any manner which is deemed by that party to be less than
totally advantageous, in that party's sole discretion.

     8.   Confidentiality.
          ---------------

     8.1  Each of the parties hereto hereby covenants and agrees that, during
the term of this Agreement and thereafter, neither it, nor any of its employees,
agents, officers or directors, will at any time make use of, divulge or disclose
to any person, firm or corporation any trade secrets or confidential or
proprietary information about the other party, its business, financial
condition, operations or otherwise (including, without limitation, any
information concerning the other party's subscribers, their names, addresses, or
telephone numbers, the terms and conditions of each Intercarrier Roaming
Services Agreement and its amendments and addenda), whatever the source of such
confidential or proprietary information. Specifically, and without limitation,
the Company acknowledges that all operational user's guides, manuals, computer
application programs, written procedures or other systems documentation
furnished to it by AWS is the sole property and proprietary information of AWS.
This confidentiality agreement shall not apply to information which is in the
public domain through no act of the party desiring to disclose. Information
contained in documents shall be considered confidential or proprietary if it
relates to information described above or the content and context of the
information is indicative of a desire to maintain confidentiality, whether or
not the document is specifically marked "confidential" or "proprietary".

     8.2  Each party agrees that such confidential or proprietary information
concerning the other party shall only be divulged or disclosed to its employees
who have a valid business reason to know such information and then only to the
extent required for the performance of such employee's duties.

     8.3  Nothing herein shall restrict the right of any party to disclose
confidential or proprietary information which is ordered to be disclosed
pursuant to judicial or other lawful governmental action, but only to the extent
so ordered, or as otherwise required by applicable law or regulation. If either
party is served with process to obtain any confidential or proprietary
information or subscriber records of the other party, that party shall
immediately notify the other party and permit the other party to conduct the
defense against disclosure.

     8.4  Upon termination of this Agreement, each party shall, upon written
request of the other party, return to the other all confidential and proprietary
information concerning the other which exists in written or electronic form.

     8.5  Each of the parties acknowledges and confirms that any failure on its
part to adhere strictly to the terms and conditions of this paragraph is likely
to cause substantial and irreparable injury to the other party. Accordingly,
each party confirms and agrees that, in addition to all other remedies to which
the other party may be entitled under this Agreement or at law or in equity, the
other party shall be entitled to specific performance and other equitable
relief, including temporary relief.

                                       8
<PAGE>

     9.   Term and Termination.
          ---------------------

     9.1  This Agreement shall run for an initial term of two years, commencing
on the date of this Agreement. It shall automatically renew for additional
successive terms of one year each, unless either party gives the other party
written notice of its intent not to renew at least ninety (90) days prior to the
termination of the then-current term.

     9.2  Either party may terminate this Agreement (except for any obligations
which survive termination) for any reason or for no reason upon one hundred
eighty (180) days prior written notice to the other party.

     9.3  Either party may terminate this Agreement (except for any obligations
which survive termination) for any of the following reasons:

          9.3.1  Upon material breach of the other party which is not cured or
     for which cure is not reasonably commenced within 30 days after notice of
     claimed breach;

          9.3.2  Immediately by either party, after reasonable prior notice, if
     the other party's operations materially and unreasonably interfere with its
     operations and such interference is not eliminated within 10 days;

     9.4  AWS may terminate this Agreement (except for any obligations which
survive termination) in the event that the Company is no longer a member in good
standing with the NACN.

     9.5  AWS may terminate this Agreement with respect to any Intercarrier
Roaming Services Agreement in accordance with Section 1.

     9.6  AWS may terminate its obligations with respect to certain provisions
under this Agreement:

          9.6.1  with respect to the EDS PCC Agreement in the event such
     agreement expires or terminates; and

          9.6.2  with respect to the Roaming Administration Services as set
forth in Section 2.1 above.

     9.7  Section 1 shall survive any termination by AWS pursuant to Section 9.4
or 9.5.

     10.  Events Upon Termination. Upon termination of this Agreement for
          -----------------------
whatever reason, each party shall immediately (or upon final accounting) pay all
amounts owing to the other parties hereunder, whether due or to become due.

                                       9
<PAGE>

     11.   Representations and Warranties of the Company. The Company hereby
           ---------------------------------------------
represents and warrants to AWS the following:

     11.1  It is duly organized and validly existing under the laws of the
     jurisdiction of its organization.

     11.2  It has full power and authority to execute and perform this
Agreement.

     11.3  The execution, delivery and performance of this Agreement has been
duly authorized by all necessary action on its part and is binding and
enforceable against it.

     11.4  It is and for the term of this Agreement will remain qualified to
hold a wireless operating license for the areas listed on Schedule A pursuant to
the rules and regulations of the Federal Communications Commission any state
authority with jurisdiction over the areas identified on Schedule A.

     12.   Notices and Other Communications.
           --------------------------------

     12.1  All notices required hereunder shall be in writing and shall be
deemed to have been duly delivered effective upon receipt if personally
delivered, or upon mailing if mailed by prepaid overnight express service,
addressed to the following:

                   If to AWS:

                   AT&T Wireless Services, Inc.
                   Carrier Relations
                   7277 164/th/ Avenue, N.E.,
                   Redmond, Washington 98052

                   With a copy to:

                   AT&T Wireless Services, Inc.
                   7277 164/th/ Avenue, N.E.,
                   Redmond, Washington 98052
                   Attn:  Legal Department.

                   If to the Company:

                   Holding Company
                   1010 N. Glebe Road
                   Arlington, VA 22201
                   Attn:  Product Development-Roaming

                                      10
<PAGE>

              With a copy to:
              Holding Company
              1010 N. Glebe Road
              Arlington, VA 22201
              Attn:  Legal Department

     12.2  For purposes of communication in order to administer this Agreement
effectively, the parties designate the following contact persons for the subject
matters set forth for them below. Either party may change the information with
respect to its designated contacts under this Section 12.2 upon oral or written
notice to the other party.

              TeleCorp Customer Care Contact
              Name: Scott Weismiller Tel: Tel: 703-236-1100 Fax: 703-236-1101

              TeleCorp Switch Update/Technical Contact
              Name: Curt Gervelis Tel: 703-236-1100 Fax: 703-236-1101

              TeleCorp Finance/Accounting Contact
              Name: Chris Schrand/Bill Baker Tel: 703-236-1100 Fax: 703-236-1101

              [AWS Customer Care Contact
              Name: David Mansisidor Tel: 425-803-8821 Fax: 425-828-1390]

              [AWS Switch Update/Technical Contact
              Name: David Mansisidor Tel: 425-803-8821 Fax: 425-828-1390]

              [AWS Finance/Accounting Contact
              Name: Mary Hawes Tel: 425-828-1308 Fax: 425-828-1390]

     13.   Miscellaneous Provisions.
           ------------------------

     13.1  Attorneys' Fees and Costs. In the event of any action at law or in
           -------------------------
equity concerning the enforcement or interpretation of the terms of this
Agreement, the prevailing party shall be entitled to reimbursement for
reasonable attorneys' fees, costs, and necessary disbursements in addition to
any other relief to which it may show itself to be entitled.

     13.2  No Joint Venture. Nothing in this Agreement is intended, or shall be
           ----------------
construed, to create a joint venture, partnership or other common business
entity as among AWS and TeleCorp. Neither of the parties shall have the
authority to accept legal process on behalf of the other party. Nothing herein
gives TeleCorp or AWS claim to the subscribers of the other or to revenues of
the other derived from its respective system. Both parties shall be solely
responsible for the operation of its systems or businesses, including but not
limited to payment of wages, benefits, taxes for employees and sales or income
taxes.

                                      11
<PAGE>

         13.3  Governmental Approval. The performance of any obligations of any
               ---------------------
party hereunder, or the exercise of any rights hereunder by any party hereto
that may require FCC or other governmental authority approval, shall be subject
to obtaining such approval. Both parties agree to take no action under this
Agreement which may place the other party in non-compliance with known and
applicable government regulations.

         13.4  Governing Law. This Agreement shall be construed under and in
               --------------
accordance with the Laws of the State of Washington.

         13.5  Assignment. This Agreement and the duties and obligations
               ----------
hereunder may not be assigned by either party without the express written
consent of the other party and an agreement by the assignee to be fully bound by
the terms and conditions hereof; provided, however, that such consent will not
be unreasonably withheld; and, provided further, that AWS may assign its rights
and obligations to an affiliate without obtaining the consent of the Company.
The Company acknowledges that AWS may subcontract any or all of its duties under
this Agreement to a third party. In the event AWS assigns this Agreement to a
third party, the Company may terminate this Agreement upon 90 days' written
notice within 30 days of such assignment.

         13.6  No Third-Party Beneficiary. This Agreement is not intended, nor
               --------------------------
shall it be construed, to create or convert any right in or upon any person or
entity not a party to this Agreement, unless specifically set forth in this
Agreement.

         13.7  Parties Bound. This Agreement shall be binding upon and inure to
               -------------
the benefit of the parties hereto and their respective heirs, executors,
administrators, legal representatives, successors and assigns where permitted by
this Agreement.

         13.8  Severability. In case any one or more of the provisions contained
               ------------
in this Agreement shall for any reason be held by any arbitration tribunal or
court of competent jurisdiction to be invalid, illegal or unenforceable in any
respect, such invalidity, illegality or unenforceability shall not affect any
other provision thereof, and this Agreement shall be construed as if such
invalid, illegal, or unenforceable provisions were deleted, and replaced with
enforceable provisions, which as nearly as possible, give effect to the intent
of such invalid, illegal or unenforceable provisions.

         13.9  Entire Agreement. This Agreement constitutes the sole and only
               ----------------
agreement of the parties with respect to the services described herein and
supersedes any prior understanding or written or oral agreements between the
parties respecting the within subject matter. In the event another form or
invoice is used for provision of the services and such form or invoice contains
terms or conditions different from those set forth herein, the parties agree
that the language of this Agreement shall control.

         13.10 Section Headings. The headings of the several sections and
               ----------------
paragraphs of this Agreement are inserted for convenience of reference only and
are not intended to be part of or to affect the meaning or interpretation of
this Agreement.

                                       12
<PAGE>

         13.11 No Waiver. Either party's failure at any time to enforce any of
               ---------
the provisions of this Agreement or any right with respect thereto, or to
exercise any option herein provided, will in no way be construed to be a waiver
of such provisions, rights or options or in any way to affect the validity of
this Agreement. The exercise by either party of any rights or options herein
shall not preclude or prejudice the exercising thereafter of the same or other
rights under this Agreement.

         13.12 Dispute Resolution.
               ------------------

         (a)   All claims and disputes relating in any way to the performance,
interpretation, validity, or breach of this Agreement, including but not limited
to a claim based on or arising from an alleged tort, shall be resolved as
provided in this Section 13.12. It is the intent of the parties that any
disagreements be resolved amicably to the greatest extent possible.

         (b)   If a disagreement cannot be resolved by the representatives of
the parties with day-to-day responsibility for this Agreement, such matter shall
be referred to an executive officer of each of the parties. The executive
officers shall conduct face-to-face negotiations at a neutral location or such
other location as shall be mutually agreed upon. If these representatives are
unable to resolve the dispute within ten business days after either party
requests the involvement of the executive officers, then either party may, but
is not required to, refer the matter to mediation or arbitration, as applicable
in accordance with this Section 13.12.

         (d)   In any case where the amount claimed or at issue is Five Hundred
Thousand Dollars ($500,000.00) or more and the parties are unsuccessful in
resolving the disagreement, the parties agree to submit the disagreement to
non-binding mediation upon written notification by either party. The parties
shall mutually select an independent mediator experienced in telecommunications
system disputes. The specific format for the mediation shall be left to the
discretion of the mediator. If mediation does not result in resolution of the
disagreement within thirty days of the initial request for mediation, then
either party may, but is not required to, refer the matter to arbitration.

         (e)   Any disagreement not finally resolved in accordance with the
foregoing provisions of this Section 13.12 shall, upon written notice by either
party to the other, be resolved by final and binding arbitration. Subject to
this Section, such arbitration shall be conducted through, and in accordance
with the rules of, JAMS/Endispute. A single neutral arbitrator shall decide all
disputes. Each party shall bear its own expenses with respect to the
arbitration, except that the costs of arbitration proceeding itself, including
the fees and expenses of the arbitrator, shall be shared equally by the parties.
The arbitration shall take place in a neutral location selected by the
arbitrator. The arbitrator may permit discovery to the full extent permitted by
the Federal Rules of Civil Procedure or to such lesser extent as the arbitrator
determines is reasonable. The arbitrator shall be bound by and strictly enforce
the terms of this Agreement. The arbitrator shall make a good faith effort to
apply applicable law, but an arbitration decision and award shall not be subject
to review because of errors of law. The arbitrator shall have the sole authority
to resolve issues of the arbitrability of any disagreement, including the
applicability or running of any applicable statute of limitation. The arbitrator
shall

                                       13
<PAGE>

not have power to award damages in connection with any dispute in excess of
actual compensatory damages nor to award punitive damages nor any damages that
are excluded under this Agreement and each party irrevocably waives any claim
thereto. The award of any arbitration shall be final, conclusive and binding on
the Parties. Judgment on the award may be entered in any court having
jurisdiction over the Party against which the award was made. Nothing contained
in this Section 13.12 shall be deemed to prevent either party from seeking any
interim equitable relief, such as a preliminary injunction or temporary
restraining order, pending the results of the arbitration. The United States
Arbitration Act and federal arbitration law shall govern the interpretation,
enforcement, and proceedings pursuant to the arbitration clause in this
Agreement.

         (f)   No action or arbitration, regardless of form, may be brought by
either party more than two (2) years from the date of the event which gave rise
to such action.

                                       14
<PAGE>

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

                                     AT&T Wireless Services, Inc.

                                     By: __________________________________
                                     Name:
                                     Title:

                                     HOLDING COMPANY

                                     By: __________________________________
                                     Name:
                                     Title:

                                       15
<PAGE>

                                   EXHIBIT A

                            Holding Company System

     [To be updated and provided at Closing]

                                       16
<PAGE>

                                  EXHIBIT A-1

                            Other Wireless Carriers

                    [To be updated and provided at Closing]

                                       17
<PAGE>

Effective 7/16/98

                                  Exhibit A-1

             Carrier_Name                                  Carrier_Shortname
VALLEY TELECOMMUNICATIONS COMPANY                      VALLEY TELECOMMUNICATIONS
WESTERN WIRELESS CORPORATION                           WESTERN WIRELESS
COMCAST CELLULAR CORPORATION                           COMCAST CELLULAR
HOUSTON CELLULAR TELEPHONE CO                          HOUSTON CELL
WESTEL - INDIANAPOLIS TELEPHONE COMPANY                WESTEL
AT&T WIRELESS SERVICES, INC.                           AWS
SYGNET COMMUNICATIONS INC.                             SYGNET COMM INC.
UNITED STATES CELLULAR CORP                            U.S. CELLULAR
MERCURY CELLULAR INCORPORATED                          MERCURY CELLULAR
ALLTEL MOBILE COMMUNICATIONS                           ALLTEL
PALMER WIRELESS INC.                                   PALMER WIRELESS
GALVESTON CELLULAR TELEPHONE CO.                       GALVESTON CELL
PETROLEUM COMMUNICATIONS                               PETROCOM
SANTA CRUZ CELLULAR TELEPHONE CO.                      SANTA CRUZ CELL.
APPALACHIAN CELLULAR                                   APPALACHIAN CELLULAR
SPRINGWICH CELLULAR LTD PARTNERSHIP                    SNET CELLULAR
ARCTIC SLOPE TELECOMM. & CELLULAR, INC.                ARCTIC SLOPE CELLULAR
DOBSON CELLULAR SYSTEMS OF KS/MO                       DCS OF KS/MO
BACHOW/COASTEL OPERATIONS, INC.                        COASTEL COMMUNICATIONS
ALLEGAN CELLULAR L.P.                                  ALLEGAN CELLULAR
EASTERBROOKE CELLULAR CORP - RCM                       EASTERBROOKE CELLULAR
LAKE HURON CELLULAR CORPORATION                        LAKE HURON CELLULAR
TEXAS 16 CELLULAR TELEPHONE COMPANY                    TEXAS 16 CELLULAR
TRIAD CELLULAR PREVIOUSLY C-1 N. TEXAS                 TRIAD CELLULAR
METACOMM CELLULAR PARTNERS                             METACOMM CELLULAR
BLACKWATER CELL/DOUGLAS TELECOMMUNICATIONS             BLACKWATER CELLULAR
ALPHA CELLULAR                                         C-1 COLUMBUS
CELLULAR COMM OF PUERTO RICO INC                       CCPR
PRICELLULAR CORPORATION                                PRICELLULAR
GREAT LAKES OF IOWA, INC.                              C-1 GREAT LAKES OF IOWA
DOBSON CELLULAR SYSTEMS INCORPORATED                   DOBSON CELLULAR
CAL-ONE CELLULAR                                       CAL-ONE CELLULAR
MERCURY COMMUNICATIONS                                 MERCURY COMMUNICATIONS
HLD CELLULAR                                           HLD CELLULAR
IFC CELLULAR PARTNERS                                  C-1 FREDERICK
BLUE MOUNTAIN CELLULAR                                 BLUE MOUNTAIN CELLULAR
CELLULAR ONE OF SOUTHWEST FLORIDA                      C-1 SW FLORIDA
UNIVERSAL TELECELL, INC.                               UNITEL INC.

                                       18
<PAGE>

                                   EXHIBIT B

                        Roaming Administration Services

1.   Administration Services (AS)

The AS will include various services that AWS will perform to manage the
Company's roaming program.

1.1  Reports and Bills. Each month during the term of this Agreement, within a
     -----------------
reasonable period of time after receipt by AWS of information regarding the
Roamer activity during the prior Settlement Period, AWS shall provide the
Company with a report summarizing Roamer activity during the prior Settlement
Period.

1.2  Exchange of Information. AWS shall provide Other Wireless Carriers and the
     -----------------------
North American Cellular Network with information (including, without limitation,
NPA/NXX and number range combinations) provided to AWS by the Company pursuant
to the Intercarrier Roamer Services Agreement between AWS and the Company that
will enable the Company's subscribers to roam in the markets owned by Other
Wireless Carriers. Further, AWS shall provide the Company with information
(including, without limitation, NPA/NXX combinations and MINs) provide to AWS by
Other Wireless Carriers and the NACN pursuant to roaming agreements that will
enable the subscribers of Other Wireless Carriers to roam in the wireless
systems identified in Exhibit A-1.

1.3  Outcollect Table Maintenance. In the event that the Company uses CBIS as
     ----------------------------
its billing vendor, AWS will maintain the Macro/Cell tables necessary to bill
subscribers of AWS and Other Wireless Carriers for use of the  Company
network. Specifically, AWS agrees to maintain the Roamer Outcollect Maintenance
(070101) and roamer Surcharge Maintenance (070102) tables including bi-weekly
updates of new NPA/NXX information, maintenance required by changes to rate
agreements and corrections identified through the course of AWS' regular
operations work.

1.4  Fraud Brownout Notifications. AWS agrees to serve as the request processor
     ----------------------------
and single point of contact between the Company, on the one hand, and AWS and
Other Wireless Carriers, on the other hand, for the exchange of suspected
fraudulent use notifications and NPA/NXX pull and reload requests related to
fraudulent use of Company NPA/NXX's on the networks of AWS and Other Wireless
Carriers and the NPA/NXX's of AWS and Other Wireless Carriers on the network of
the Company. AWS will receive and forward all requests on a daily (Monday -
Friday) basis to the appropriate party for action. In addition, AWS agrees to
maintain and distribute as requested historical data regarding fraud pull and
reload request data.

                                       19
<PAGE>

1.5    Rate Monitoring. AWS will monitor incollect rates charged to the Company
       ---------------
and outcollect rates charged by the Company. If an incorrect roaming rate is
charged by the Company to an Other Wireless Carrier, and the Other Wireless
Carrier invoices AWS for amounts charged in excess of the amounts that should
have been charged under the applicable Intercarrier Roaming Services Agreement,
AWS shall refund all amounts in excess of the contract rate back to the Other
Wireless Carrier within forty-five days of notification by the Other Wireless
Carrier. If an incorrect roaming rate is charged to the Company by an Other
Wireless Carrier so that the amounts charged in a month are more than $200 over
the amounts that should have been charged under the applicable Intercarrier
Roaming Services Agreement, AWS will invoice the Other Wireless Carrier for all
amounts in excess of the contract rate. AWS shall not be responsible for any
amounts undercharged by AWS on behalf of the Company to any Other Wireless
Carrier.

2.     Full Visibility (FV) Services - Optional Service. FV services are adjunct
       ------------------------------------------------
to XLI service. FV provides a mechanism for receiving transaction information on
all call attempts made by a Roamer who subscribes to a carrier using XLI while
roaming on a market serviced by the GTE TSI network for validation. The FV
services include the following features:

2.1    When a subscriber from a carrier using XLI is roaming in an area served
by GTE for validation is found negative in GTE's negative file, GTE sends a
visibility notification message which can then be used to report the activity.
When a subscriber from a carrier using XLI is roaming in an area served by GTE
for validation, and is not found in the GTE negative file, but has a valid
status in their industry file, GTE will send a visibility notification message
which can then be used to report the activity.

2.2    Additional options for updating visibility settings by NPA/NXX ranges or
by System Identification ("SID") or Billing Identification ("BID") are
available.

2.3    Home carrier enabling/disabling option by NPA/NXX range or by SID/BID
within a 45-day period.

2.4    Availability of cloning activity reports for Roamers on systems using GTE
and XLI.

3.     Intercarrier Settlement Services (ISS). With ISS, AWS will instruct EDS
       --------------------------------------
PCC to edit roaming records to verify the billable status of these records.
These edits will be performed in accordance with the then current CIBER
standards. AWS will also provide certain standard reports in connection with
these edits.

3.1    Edits. The records will be edited against the CIBERNET standards, using a
       -----
60-day standard for the Call Age Edit. Any records which do not satisfy these
standards will be returned to the serving carrier.

3.1.1  Negative File Edit

                                       20
<PAGE>

3.1.2    CIBER Edit
3.1.3    NPA/NXX Edit - Proper Routing of Call
3.1.4    Call Age Edit
3.1.5    Out-of-Sequence Batch Edits
3.1.6    Duplicate Call Edit
3.1.7    Roamer Agreement Edit
3.1.8    Out of Balance Edit
3.1.9    Invalid Record Type Edit
3.1.10   Incorrect Rate Edit
3.1.11   Additional Edits Per CIBER Standard Table 3

3.2    Reports. The following reports reflect activity within a settlement
       -------
cycle. Each report is produced at the end of each settlement cycle (the 1st
through the 15th of the calendar month and the 16th of a calendar month through
month end).

3.2.1  Incollect Reports which summarize the amounts owed by the Company for
Roamer calls to each of AWS and each Other Wireless Carrier.

3.2.2  Outcollect Reports which summarize the amounts owed to the Company for
Roamer calls from each of AWS and each Other Wireless Carrier.

3.2.3  Net Settlement Reports which summarize the net amount owed to or owed by
the Company for Roamer calls with respect to each of AWS and each Other Wireless
Carrier.

4.     Net Settlement Services (NSS)
       -----------------------------

4.1    Clearinghouse Functions. AWS shall provide Roamer clearinghouse functions
       -----------------------
for the Company, such that the Company's Incollect Obligations are netted
against the Company's Outcollect Obligations for AWS and each Other Wireless
Carrier. To the extent that the Incollect Obligations, Fees and Expenses exceed
the net Outcollect Obligations with respect to AWS or with respect to any Other
Wireless Carrier, the Company shall pay such net Incollect Obligations, Fees and
Expenses to AWS. To the extent that net Outcollect Obligations exceed net
Incollect Obligations, Fees and Expenses with respect to AWS or any Other
Wireless Carrier, AWS shall pay such net Outcollect Obligations to TeleCorp.

4.2    Fraud Settlement Functions. AWS will invoice Other Wireless Carriers for
       --------------------------
Roamer fraud, under the terms of any Intercarrier Roaming Services Agreements in
place with Other Wireless Carriers. AWS will provide invoices to the Company for
Roamer fraud incurred by Other Wireless Carriers and make payments to Other
Wireless Carriers for these invoices. Information to be included in any invoice
to AWS or any Other Wireless Carrier must be in the format required by AWS, as
that format may change from time to time. This information must be

                                       21
<PAGE>

submitted to AWS sufficiently close to the date of the call record at issue in
order to permit AWS to invoice Other Wireless Carriers.

5.   Positive Roamer Verification (PRV) - Optional Service The PRV service will
     -----------------------------------------------------
provide TeleCorp with the ability to verify the billing status of Roamers from
Other Wireless Carriers not connected to TeleCorp through the NACN or other
network or carriers which provide alternative SS7 verification services. This
verification will be accomplished through comparison of the Roamer's MIN an ESN
combination with a database designed to identify potential fraudulent use. This
information can be used by the Company to deny service to callers when roaming
in the Company System.

                                       22
<PAGE>

                                   EXHIBIT C

                               Fees and Expenses

Service                   Fee
                          ---

PRV (optional)            $0.21 per unique ESN validation per each calendar day.

XLI (optional)            $0.16 per unique ESN validation per each calendar day.
                          $1000.00 per SID/BID minimum (waived if transaction
                          charges are greater than or equal to $1000.00)

FULL VISIBILITY           $0.025/transaction
(optional)                $500.00 for first SID/BID using FV.
                          $50.00 for additional SID/BIDs using FV.
                          $500.00 Installation - one time charge.

ISS                       $0.015 per outcollect record
                          $0.015 per incollect record

                          Monthly minimum:
                          Up to 100K records monthly: $2,000 per SID/BID flat
                          fee and no record fee.
                          Greater than 100K records monthly: $1,000 per SID/BID
                          plus record fee for records above 100K

CLEARINGHOUSE             $1000.00 per SID/BID
SET UP FEE

ROAM AGREEMENT            $25,000.00
SET UP FEE

CIBERNET Fees             $0.005 per outcollect amount dollar owed to the
                          Company.

Special Processing and    As agreed by the parties in writing
Reports

Clearinghouse Financial   $50.00 per market per Settlement Period
Reports

The Company will also pay all postage, handling, overnight mail fees, and any
other fees incurred by AWS as the result of complying with special requests from
the Company for services and reports not described in this Agreement or for
special modifications to any service or report.

AWS may modify the fees outlined above with 30 days' prior written notice.

                                       23

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