<PAGE>

                                                                   EXHIBIT 10.22

                     WARRANT REGISTRATION RIGHTS AGREEMENT


                                by and between

                                  iPCS, INC.

                                      and

                         DONALDSON, LUFKIN & JENRETTE
                            SECURITIES CORPORATION

                                      and

                           TD SECURITIES (USA) INC.


                           Dated as of July 12, 2000



                   ________________________________________

              300,000 Warrants Initially Exercisable to Purchase

                       2,982,699 Shares of Common Stock

                   ________________________________________
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                     WARRANT REGISTRATION RIGHTS AGREEMENT

          This Warrant Registration Rights Agreement (this "Agreement") is made
                                                            ---------
and entered into as of July 12, 2000, by and between iPCS,  Inc., a Delaware
corporation (the "Issuer"), and Donaldson, Lufkin & Jenrette Securities
                  ------
Corporation and TD Securities (USA) Inc. (the "Initial Purchasers"), which has
                                               ------------------
agreed to purchase the warrants (the " Warrants") of the Issuer issued pursuant
                                       --------
to the Warrant Agreement (the "Warrant Agreement") between the Issuer and Chase
                               -----------------
Mellon, as warrant agent (the "Warrant Agent").
                               -------------

          The Warrants are being issued and sold in connection with the offering
(the "Offering") by the Issuer of 300,000 Units each consisting of (i) $1,000
      --------
principal amount at maturity of the Issuer's 14% Senior Discount Notes due 2010
(the "Notes") and (ii) one Warrant. Each Warrant entitles the holder thereof to
      -----
purchase 9.94233 shares of the common stock, $0.01 par value ("Common Stock"),
                                                               ------------
of the Issuer, subject to adjustment as set forth in the Warrant Agreement.

          This Agreement is made pursuant to the Purchase Agreement, dated
June 29, 2000 (the "Purchase Agreement"), by and among the Issuer, iPCS Equip-
                    ------------------
ment, Inc., iPCS Wireless, Inc. and the Initial Purchasers. In order to induce
the Initial Purchasers to purchase the Warrants, the Issuer has agreed to
provide the registration rights set forth in this Agreement. The execution and
delivery of this Agreement is a condition to the obligations of the Initial
Purchasers set forth in Section 9 of the Purchase Agreement. Capitalized terms
used herein and not otherwise defined shall have the meaning assigned to them in
the Warrant Agreement.

          The parties hereby agree as follows:

SECTION 1. DEFINITIONS

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

          Act:  The Securities Act of 1933, as amended.
          ---

          Affiliate:  As defined in Rule 144.
          ---------

          Black Out Notice:  As defined in Section 4(b) hereof.
          ----------------

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          Black Out Period:  As defined in Section 3(a) hereof.
          ----------------

          Closing Date:  The date hereof.
          ------------

          Commission:  The Securities and Exchange Commission.
          ----------

          Exchange Act:  The Securities Exchange Act of 1934, as amended.
          ------------

          Expiration Date: 5:00 p.m. New York City time on July 15, 2010.
          ---------------

          Holders:  As defined in Section 2 hereof.
          -------

          Prospectus:  The prospectus included in a Registration Statement at
          ----------
the time such Registration Statement is declared effective, as amended or
supplemented by any prospectus supplement and by all other amendments thereto,
including post-effective amendments, and all material incorporated by reference
into such Prospectus.

          Registration Statement:  Any registration statement of the Issuer
          ----------------------
relating to the registration for resale of Transfer Restricted Securities that
is filed pursuant to the provisions of this Agreement and including the
Prospectus included therein, all amendments and supplements thereto (including
post-effective amendments) and all exhibits and material incorporated by
reference therein.

          Rule 144: Rule 144 promulgated under the Act.
          --------

          Transfer Restricted Securities: (a) Each Warrant and Warrant Share
          ------------------------------
held by an Affiliate of the Issuer and (b) each other Warrant and Warrant Share
until the earlier to occur of (i) the date on which such Warrant or Warrant
Share (other than any Warrant Share issued upon exercise of a Warrant in
accordance with a Registration Statement) has been disposed of in accordance
with a Registration Statement and (ii) the date on which such Warrant or Warrant
Share (or the related Warrant) is distributed to the public pursuant to Rule 144
under the Act.

SECTION 2. HOLDERS

          A Person is deemed to be a holder of Transfer Restricted Securities
(each, a "Holder") whenever such Person is the holder of record of Transfer
          ------
Restricted Securities.

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SECTION 3. SHELF REGISTRATION

          (a)  Shelf Registration.  The Issuer shall prepare and cause to be
               ------------------
filed with the Commission on or before 90 days from the Closing Date pursuant to
Rule 415 under the Securities Act a Registration Statement on the appropriate
form relating to resales of Transfer Restricted Securities by the Holders
thereof. The Issuer shall use its reasonable best efforts to cause the
Registration Statement to be declared effective by the Commission on or before
180 days after the Closing Date.

          To the extent necessary to ensure that the Registration Statement is
available for sales of Transfer Restricted Securities by the Holders thereof
entitled to the benefit of this Section 3(a), the Issuer shall use its
reasonable best efforts to keep any Registration Statement required by this
Section 3(a) continuously effective, supplemented, amended and current as
required by and subject to the provisions of Section 4(a) hereof and in
conformity with the requirements of this Agreement, the Act and the policies,
rules and regulations of the Commission as announced from time to time, until
the earlier of (A) the Expiration Date and (B) the first date as of which all
Warrants have been exercised by the Holders thereof; provided that such
obligation shall expire before such date if the Issuer delivers to the Warrant
Agent a written opinion of counsel to the Issuer (which opinion of counsel shall
be reasonably satisfactory to the Warrant Agent) that all Holders (other than
Affiliates of the Issuer reasonably) of Warrants and Warrant Shares may resell
the Warrants and the Warrant Shares without registration under the Act and
without restriction as to the manner, timing or volume of any such sale; and
provided, further, that notwithstanding the foregoing, any Affiliate of the
Issuer may, with notice to the Issuer, require the Issuer to keep the
Registration Statement continuously effective for resales by such Affiliate for
so long as such Affiliate holds Warrants or Warrant Shares, including as a
result of any market-making activities or other trading activities of such
Affiliate.  Notwithstanding the foregoing, the Issuer shall not be required to
amend or supplement the Registration Statement, any related prospectus or any
document incorporated therein by reference, for a period (a "Black Out Period")
                                                             ----------------
not to exceed, for so long as this Agreement is in effect, an aggregate of 60
days in any calendar year, in the event that (i) there shall exist any fact or
any event shall have occurred and as a result thereof the Registration
Statement, any related prospectus or any document incorporated therein by
reference as then amended or supplemented would, in the Issuer's good faith
judgment, contain an untrue statement of a material fact or omit to state a
material fact necessary in order to make the statements therein, in the light of
the circumstances under which they were made, not misleading, and (ii)(A) the
Issuer determines in its good faith judgment that the disclosure of such event
at such time could reasonably be expected to have a material adverse effect on

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the business, operations or prospects of the Issuer or (B) the disclosure
otherwise relates to a material business transaction or proposed material
business transaction which has not yet been publicly disclosed; provided that
such Black Out Period shall be extended for any period, not to exceed an
aggregate of 45 days in any calendar year, during which the Commission is
reviewing any proposed amendment or supplement to the Registration Statement,
any related prospectus or any document incorporated therein by reference which
has been filed by the Issuer; and provided, further, that no Black Out Period
may be in effect during the three months prior to the Expiration Date.

         (b)  Provision by Holders of Certain Information in Connection with the
              ------------------------------------------------------------------
Registration Statement.  No Holder of Transfer Restricted Securities may include
----------------------
any of its Transfer Restricted Securities in any Registration Statement pursuant
to this Agreement unless and until such Holder furnishes to the Issuer in
writing, within 20 days after receipt of a request therefor, the information
specified in Item 507 or 508 of Regulation S-K, as applicable, of the Act for
use in connection with any Registration Statement or Prospectus or preliminary
Prospectus included therein. No Holder of Transfer Restricted Securities shall
be entitled to liquidated damages pursuant to Section 8 unless and until such
Holder shall have provided all such information and the Company shall have a
period of three Business Days to include such information in any Shelf
Registration Statement or Prospectus or preliminary Prospectus included therein.
Each selling Holder agrees to promptly furnish additional information required
to be disclosed in order to make the information previously furnished to the
Issuer by such Holder not materially misleading.

SECTION 4. REGISTRATION PROCEDURES

         (a)  In connection with the Registration Statement and any related
Prospectus required by this Agreement, the Issuer shall:

              (i)    use its reasonable best efforts to effect such registration
     to permit the sale of the Transfer Restricted Securities being sold in
     accordance with the intended method or methods of distribution thereof (as
     indicated in the information furnished to the Issuer pursuant to Section
     3(b) hereof), and pursuant thereto the Issuer will prepare and file with
     the Commission a Registration Statement relating to the registration on any
     appropriate form under the Act, which form shall be available for the sale
     of the Transfer Restricted Securities in accordance with the intended
     method or

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<PAGE>

     methods of distribution thereof within the time periods and otherwise in
     accordance with the provisions hereof;

              (ii)   use its reasonable best efforts to keep such Registration
     Statement continuously effective and provide all requisite financial
     statements for the period specified in Section 3 of this Agreement. Upon
     the occurrence of any event that would cause any such Registration
     Statement or the Prospectus contained therein (A) to contain an untrue
     statement of material fact or omit to state any material fact necessary to
     make the statements therein, in the light of the circumstances under which
     they were made, not misleading or (B) not to be effective and usable for
     resale of Transfer Restricted Securities during the period required by this
     Agreement, the Issuer shall, subject to Section 3(a), file promptly an
     appropriate amendment to such Registration Statement or a supplement to the
     Prospectus, as applicable, curing such defect, and, in the case of an
     amendment, use its reasonable best efforts to cause such amendment to be
     declared effective as soon as practicable;

              (iii)  prepare and file with the Commission such amendments
     and post-effective amendments to the applicable Registration Statement as
     may be necessary to keep such Registration Statement effective for the
     applicable period set forth in Section 3; cause the Prospectus to be
     supplemented by any required Prospectus supplement, and as so supplemented
     to be filed pursuant to Rule 424 under the Act, and to comply fully with
     Rules 424, 430A and 462, as applicable, under the Act in a timely manner;
     and comply with the provisions of the Act with respect to the disposition
     of all securities covered by such Registration Statement during the
     applicable period in accordance with the intended method or methods of
     distribution by the sellers thereof set forth in such Registration
     Statement or supplement to the Prospectus;

              (iv)   advise the Holders named in any Shelf Registration
     Statement and the Initial Purchasers promptly and, if requested by any of
     such Persons, confirm such advice in writing, (A) when the Prospectus or
     any Prospectus supplement or post-effective amendment has been filed, and,
     with respect to any applicable Registration Statement or any post-effective
     amend ment thereto, when the same has become effective, (B) of any request
     by the Commission for amendments to the Registration Statement or
     amendments or supplements to the Prospectus or for additional information
     relating thereto, (C) of the issuance by the Commission of any stop order
     suspending the

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<PAGE>

     effectiveness of the Registration Statement under the Act or of the
     suspension by any state securities commission of the qualification of the
     Transfer Restricted Securities for offering or sale in any jurisdiction, or
     the initiation of any proceeding for any of the preceding purposes, and (D)
     of the existence of any fact or the happening of any event that makes any
     statement of a material fact made in the Registration Statement, the
     Prospectus, any amendment or supplement thereto or any document
     incorporated by reference therein untrue, or that requires the making of
     any additions to or changes in the Registration Statement in order to make
     the statements therein not misleading, or that requires the making of any
     additions to or changes in the Prospectus in order to make the statements
     therein, in the light of the circumstances under which they were made, not
     misleading. If at any time the Commission shall issue any stop order
     suspending the effectiveness of the Registration Statement, or any state
     securities commission or other regulatory authority shall issue an order
     suspending the qualification or exemption from qualification of the
     Transfer Restricted Securities under state securities or Blue Sky laws, the
     Issuer shall use its reasonable best efforts to obtain the withdrawal or
     lifting of such order at the earliest possible time;

              (v)    subject to Section 4(a)(ii), if any fact or event
     contemplated by Section 4(a)(iv)(D) hereof shall exist or have occurred,
     prepare a supplement or post-effective amendment to the Registration
     Statement or related Prospectus or any document incorporated therein by
     reference or file any other required document so that, as thereafter
     delivered to the purchasers of Transfer Restricted Securities, the
     Prospectus will not contain an untrue statement of a material fact or omit
     to state any material fact necessary to make the statements therein, in the
     light of the circumstances under which they were made, not misleading;

              (vi)   furnish to the Holders named in any Shelf Registration
     Statement and the Initial Purchasers, before filing with the Commission,
     copies of any Registration Statement or any Prospectus included therein or
     any amendments or supplements to any such Registration Statement or
     Prospectus (including all documents incorporated by reference after the
     initial filing of such Registration Statement), which documents will be
     subject to the review and comment of such Persons, if any, for a period of
     at least five Business Days, and the Issuer will not file any such
     Registration Statement or Prospectus or any amendment or supplement to any
     such Registration State ment or Prospectus (including all such documents
     incorporated by reference) to which any of such Persons shall reasonably
     object within five Business

                                       6
<PAGE>

     Days after the receipt thereof. Such Persons shall be deemed to have
     reasonably objected to such filing if such Registration Statement,
     amendment, Prospectus or supplement, as applicable, as proposed to be
     filed, contains an untrue statement of a material fact or omits to state
     any material fact necessary to make the statements therein, in the light of
     the circumstances under which they were made, not misleading or fails to
     comply with the applicable requirements of the Act;

              (vii)  promptly prior to the filing of any document (other than
     any document relative to the ordinary course of the Issuer's business) that
     is to be incorporated by reference into a Registration Statement or
     Prospectus, provide copies of such document to the Holders named in any
     Shelf Registration Statement and the Initial Purchasers, make the Issuer's
     representatives available for discussion of such document and other
     customary due diligence matters, and include such information in such
     document prior to the filing thereof as the Initial Purchasers may
     reasonably request;

              (viii) make available, at reasonable times, for inspection by the
      Holders named in any Shelf Registration Statement and the Initial
      Purchasers and any attorney or accountant retained by such Persons, all
      financial and other records, pertinent corporate documents of the Issuer
      and cause the Issuer's officers, directors and employees to supply all
      information reasonably requested by the Initial Purchasers, attorney or
      accountant in connection with such Registration Statement or any post-
      effective amendment thereto subsequent to the filing thereof and prior to
      its effectiveness;

              (ix)   if requested by the Holders named in any Shelf Registration
      Statement and the Initial Purchasers, promptly include in any Registration
      Statement or Prospectus, pursuant to a supplement or post-effective
      amendment if necessary, such information as any such Person may reasonably
      request to have included therein, including, without limitation,
      information relating to the plan of distribution (the "Plan of
                                                             -------
      Distribution") of the Transfer Restricted Securities and the use of the
      ------------
      Registration Statement or Prospectus for market-making activities; and
      make all required filings of such Prospectus supplement or post-effective
      amendment as soon as practicable after the Issuer is notified of the
      matters to be included in such Prospectus supplement or post-effective
      amendment;

              (x)    furnish to the Initial Purchasers and each Holder named in
      any Shelf Registration Statement, upon request and without charge,

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<PAGE>

     at least one copy of the Registration Statement, as first filed with the
     Commission, and of each amendment thereto, including all documents
     incorporated by reference therein and all exhibits (excluding exhibits
     incorporated therein by reference);

              (xi)    deliver to the Initial Purchasers and each Holder named in
     any Shelf Registration Statement, without charge, as many copies of the
     Prospectus (including each preliminary prospectus) and any amendment or
     supplement thereto as the Initial Purchasers or such Holder reasonably may
     request; the Issuer hereby consents to the use (in accordance with law and
     subject to Section 4(b) hereof) of the Prospectus and any amendment or
     supplement thereto by each selling Person in connection with the offering
     and the sale of the Transfer Restricted Securities covered by the
     Prospectus or any amendment or supplement thereto and all market-making
     activities of the Initial Purchasers, as the case may be;

              (xii)   upon the request of the Holders named in a Shelf
     Registration Statement in connection with any underwritten offering
     pursuant to a Shelf Registration Statement, (A) enter into such agreements
     (including underwriting agreements) and make such representations and
     warranties and take all such other actions in connection therewith in order
     to expedite or facilitate the disposition of the Transfer Restricted
     Securities pursuant to any applicable Registration Statement contemplated
     by this Agreement and (B) use their respective reasonable best efforts to
     cause to be furnished a customary legal opinion of counsel to the Company
     and a customary comfort letter from the Company's independent auditors, in
     each case as may be reasonably requested by the Holders in connection with
     any sale or resale pursuant to any applicable Registration Statement. In
     such connection, the Issuer shall deliver such other documents and
     certificates as may be reasonably requested by such Holders to evidence
     compliance with the matters referred to above and with any customary
     conditions contained in any agreement entered into by the Issuer pursuant
     to this clause;

              (xiii)  prior to any public offering of Transfer Restricted
     Securities, cooperate with the selling Holders and their counsel in
     connection with the registration and qualification of the Transfer
     Restricted Securities under the securities or Blue Sky laws of such
     jurisdictions as the selling Holders may request and do any and all other
     acts or things necessary or advisable to enable the disposition in such
     jurisdictions of the Transfer Restricted Securities covered by the
     applicable Registration Statement;

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<PAGE>

     provided that the Issuer shall not be required to register or qualify as a
     foreign corporation where it is not now so qualified or to take any action
     that would subject it to the service of process in suits or to taxation,
     other than as to matters and transactions relating to the Registration
     Statement, in any jurisdiction where it is not now so subject;

              (xiv)   in connection with any sale of Transfer Restricted
     Securities that will result in such securities no longer being Transfer
     Restricted Securities, cooperate with the Holders to facilitate the timely
     preparation and delivery of certificates representing Transfer Restricted
     Securities to be sold and not bearing any restrictive legends; and to
     register such Transfer Restricted Securities in such denominations and such
     names as the selling Holders may request at least two Business Days prior
     to such sale of Transfer Restricted Securities;

              (xv)    use its reasonable best efforts to cause the disposition
     of the Transfer Restricted Securities covered by the Registration Statement
     to be registered with or approved by such other governmental agencies or
     authorities as may be necessary to enable the seller or sellers thereof to
     consummate the disposition of such Transfer Restricted Securities, subject
     to the proviso contained in clause (xiii) above;

              (xvi)   provide a CUSIP number for all Transfer Restricted
     Securities not later than the effective date of a Registration Statement
     covering such Transfer Restricted Securities and provide the Warrant Agent
     or the Transfer Agent and Registrar for the Warrant Shares, as applicable,
     with printed certificates for the Transfer Restricted Securities which are
     in a form eligible for deposit with The Depository Trust Company;

              (xvii)  otherwise use its reasonable best efforts to comply with
     all applicable rules and regulations of the Commission, and make generally
     available to its security holders with regard to any applicable
     Registration Statement, as soon as practicable, a consolidated earnings
     statement meeting the requirements of Rule 158 (which need not be audited)
     covering a twelve-month period beginning after the effective date of the
     Registration Statement (as such term is defined in Rule 158(c) under the
     Act); and

              (xviii) provide promptly to the Initial Purchaser, upon request,
     each document filed with the Commission pursuant to the requirements of
     Section 13 or Section 15(d) of the Exchange Act.

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           (b)  Restrictions on Holders.  Each Holder agrees by acquisition of a
                -----------------------
Transfer Restricted Security and the Initial Purchasers agree that, upon receipt
of the notice from the Issuer of the commencement of a Black Out Period (in each
case, a "Black Out Notice"), such Person will forthwith discontinue disposition
         ----------------
of Transfer Restricted Securities pursuant to the applicable Registration
Statement until such Person is advised in writing by the Issuer of the
termination of the Black Out Period. Each Person receiving a Black Out Notice
hereby agrees that it will either (i) destroy any Prospectuses, other than
permanent file copies, then in such Person's possession which have been replaced
by the Issuer with more recently dated Prospectuses or (ii) deliver to the
Issuer (at the Issuer's expense) all copies, other than permanent file copies,
then in such Person's possession of the Prospectus covering such Transfer
Restricted Securities that was current at the time of receipt of the Black Out
Notice.

SECTION 5. REGISTRATION EXPENSES

           All expenses incident to the Issuer's performance of or compliance
with this Agreement will be borne by the Issuer, regardless of whether a
Registration Statement becomes effective, including, without limitation: (i) all
registration and filing fees and expenses; (ii) all fees and expenses of
compliance with federal securities and state Blue Sky or securities laws; (iii)
all expenses of printing (including printing Prospectuses (whether for sales,
market-making or otherwise), messenger and delivery services and telephone;
(iv) all fees and disbursements of counsel for the Issuer; (v) if the Common
Stock shall then be listed on any national securities exchange or automated
quotation system, all application and filing fees in connection with listing the
Warrant Shares thereon, and (vi) all fees and disbursements of independent
certified public accountants of the Issuer (including the expenses of any
special audit and comfort letters required by or incident to such performance).

           The Issuer will, in any event, bear its internal expenses (including,
without limitation, all salaries and expenses of its officers and employees
performing legal or accounting duties), the expenses of any annual audit and the
fees and expenses of any Person, including special experts, retained by the
Issuer.

SECTION 6. INDEMNIFICATION

           (a)  The Issuer agrees to indemnify and hold harmless each Holder,
its directors, officers and each Person, if any, who controls such Holder
(within the meaning of Section 15 of the Act or Section 20 of the Exchange Act),
from and against any and all losses, claims, damages, liabilities, judgments,
(inclu-

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<PAGE>

ding, without limitation, any reasonable legal or other expenses incurred in
connection with investigating or defending any matter, including any action that
could give rise to any such losses, claims, damages, liabilities or judgments)
caused by any untrue statement or alleged untrue statement of a material fact
contained in any Registration Statement, preliminary prospectus or Prospectus
(or any amendment or supplement thereto) provided by the Issuer to any Holder or
any prospective purchaser of Transfer Restricted Securities, or caused by any
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading,
except insofar as such losses, claims, damages, liabilities or judgments are
caused by an untrue statement or omission or alleged untrue statement or
omission that is based upon information relating to a Holder furnished in
writing to the Issuer by or on behalf of such Holder.

          (b)  Each Holder of Transfer Restricted Securities agrees, severally
and not jointly, to indemnify and hold harmless the Issuer, its directors and
officers, and each person, if any, who controls (within the meaning of Section
15 of the Act or Section 20 of the Exchange Act) the Issuer, to the same extent
as the foregoing indemnity from the Issuer set forth in Section 6(a) hereof, but
only with reference to information relating to such Holder furnished in writing
to the Issuer by or on behalf of such Holder expressly for use in any
Registration Statement.  In no event shall any Holder, its directors, officers
or any Person who controls such Holder be liable or responsible for any amount
in excess of the amount by which the total amount received by such Holder with
respect to its sale of Transfer Restricted Securities pursuant to a Registration
Statement exceeds (i) the amount paid by such Holder for such Transfer
Restricted Securities and (ii) the amount of any damages that such Holder, its
directors, officers or any Person who controls such Holder has otherwise been
required to pay by reason of such untrue or alleged untrue statement or omission
or alleged omission.

          (c)  In case any action shall be commenced involving any person in
respect of which indemnity may be sought pursuant to Section 6(a) or 6(b) (the
"indemnified party"), the indemnified party shall promptly notify the person
 -----------------
against whom such indemnity may be sought (the "indemnifying party") in writing,
                                                ------------------
and the indemnifying party shall assume the defense of such action, including
the employ  ment of counsel reasonably satisfactory to the indemnified party and
the payment of all fees and expenses of such counsel, as incurred (except that,
in the case of any action in respect of which indemnity may be sought pursuant
to both Sections 6(a) and 6(b), a Holder shall not be required to assume the
defense of such action pursuant to this Section 6(c), but may employ separate
counsel and participate in

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<PAGE>

the defense thereof, but the fees and expenses of such counsel, except as
provided below, shall be at the expense of the Holder). Any indemnified party
shall have the right to employ separate counsel in any such action and
participate in the defense thereof, but the fees and expenses of such counsel
shall be at the expense of the indemnified party, unless (i) the employment of
such counsel shall have been specifically authorized in writing by the
indemnifying party, (ii) the indemnifying party shall have failed to assume the
defense of such action or employ counsel reasonably satisfactory to the
indemnified party or (iii) the named parties to any such action (including any
impleaded parties) include both the indemnified party and the indemnifying
party, and the indemnified party shall have been advised by such counsel that
there may be one or more legal defenses available to it which are different from
or additional to those available to the indemnifying party (in which case the
indemnifying party shall not have the right to assume the defense of such action
on behalf of the indemnified party). In any such case, the indemnifying party
shall not, in connection with any one action or separate but substantially
similar or related actions in the same jurisdiction arising out of the same
general allegations or circumstances, be liable for the fees and expenses of
more than one separate firm of attorneys (in addition to any local counsel) for
all indemnified parties and all such fees and expenses shall be reimbursed as
they are incurred. Such firm shall be designated in writing by a majority of the
Holders, in the case of the parties indemnified pursuant to Section 6(a), and by
the Issuer, in the case of parties indemnified pursuant to Section 6(b). The
indemnifying party shall indemnify and hold harmless the indemnified party from
and against any and all losses, claims, damages, liabilities and judgments by
reason of any settlement of any action (i) effected with its written consent or
(ii) effected without its written consent if the settlement is entered into more
than twenty business days after the indemnifying party shall have received a
request from the indemnified party for reimbursement for the fees and expenses
of counsel (in any case where such fees and expenses are at the expense of the
indemnifying party) and, prior to the date of such settlement, the indemnifying
party shall have failed to comply with such reimbursement request. No
indemnifying party shall, without the prior written consent of the indemnified
party, effect any settlement or compromise of, or consent to the entry of
judgment with respect to, any pending or threatened action in respect of which
the indemnified party is or could have been a party and indemnity or
contribution may be or could have been sought hereunder by the indemnified
party, unless such settlement, compromise or judgment (i) includes an
unconditional release of the indemnified party from all liability on claims that
are or could have been the subject matter of such action and (ii) does not
include a statement as to or an admission of fault, culpability or a failure to
act, by or on behalf of the indemnified party.

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<PAGE>

          (d)  To the extent that the indemnification provided for in this
Section 6 is unavailable to an indemnified party in respect of any losses,
claims, damages, liabilities or judgments referred to therein, then each
indemnifying party, in lieu of indemnifying such indemnified party, shall
contribute to the amount paid or payable by such indemnified party as a result
of such losses, claims, damages, liabilities or judgments (i) in such proportion
as is appropriate to reflect the relative benefits received by the Issuer, on
the one hand, and the Holders, on the other hand, from their sale of Transfer
Restricted Securities or (ii) if the allocation provided by clause 6(d)(i) is
not permitted by applicable law, in such proportion as is appropriate to reflect
not only the relative benefits referred to in clause 6(d)(i) hereof but also the
relative fault of the Issuer, on the one hand, and of the Holder, on the other
hand, in connection with the statements or omissions which resulted in such
losses, claims, damages, liabilities or judgments, as well as any other relevant
equitable considerations.  The relative fault of the Issuer, on the one hand,
and of the Holder, on the other hand, shall be determined by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission or alleged omission to state a material fact relates to
information supplied by the Issuer, on the one hand, or by or on behalf of the
Holder, on the other hand, and the parties' relative intent, knowledge, access
to information and opportunity to correct or prevent such statement or omission.
The amount paid or payable by an indemnified party as a result of the losses,
claims, damages, liabilities or judgments referred to above shall be deemed to
include, subject to the limitations set forth in the second paragraph of Section
6(a), any legal or other fees or expenses reasonably incurred by such
indemnified party in connection with investigating or defending any matter,
including any action that could have given rise to such losses, claims, damages,
liabilities or judgments.

          The Issuer and each Holder agree that it would not be just and
equitable if contribution pursuant to this Section 6(d) were determined by pro
rata allocation (even if the Holders were treated as one entity for such
purpose) or by any other method of allocation which does not take account of the
equitable considerations referred to in the immediately preceding paragraph.
Notwithstanding the provisions of this Section 6, no Holder, its directors, its
officers or any Person, if any, who controls such Holder shall be required to
contribute, in the aggregate, any amount in excess of the amount by which the
total received by such Holder with respect to the sale of Transfer Restricted
Securities pursuant to a Registration Statement exceeds (i) the amount paid by
such Holder for such Transfer Restricted Securities and (ii) the amount of any
damages which such Holder has otherwise been required to pay by reason of such
untrue or alleged untrue statement or omission or

                                      13
<PAGE>

alleged omission. No person guilty of fraudulent misrepresentation (within the
meaning of Section 11(f) of the Act) shall be entitled to contribution from any
person who was not guilty of such fraudulent misrepresentation. The Holders'
obligations to contribute pursuant to this Section 6(d) are several in
proportion to the respective principal amount of Transfer Restricted Securities
held by each Holder hereunder and not joint.

          (e)  The Issuer agrees that the cross indemnity and contribution
provisions of this Section 6 shall apply to the Initial Purchasers to the same
extent, on the same conditions, as it applies to Holders.

SECTION 7. RULE 144

           The Issuer agrees with each Holder, for so long as any Transfer
Restricted Securities remain outstanding and during any period in which the
Issuer is subject to Section 13 or 15(d) of the Exchange Act, to make all
filings required thereby in a timely manner in order to permit resales of such
Transfer Restricted Securities pursuant to Rule 144.

SECTION 8. LIQUIDATED DAMAGES

           (a)  Liquidated Damages. The Issuer and the Initial Purchasers agree
                ------------------
that the Holders will suffer damages if the Issuer fails to fulfill its
obligations pursuant to Section 3 and 4 of this Agreement and that it would not
be possible to ascertain the extent of such damages.  Accordingly, in the event
of such failure by the Issuer to fulfill such obligations, the Issuer hereby
agrees to pay liquidated damages ("Liquidated Damages") to each Holder under the
                                   ------------------
circumstances and to the extent set forth below:

                (i)   if the Registration Statement has not been filed with the
     Commission within 90 days after the Closing Date;

                (ii)  if the Registration Statement has not been declared
     effective by the Commission within 180 days after the Closing Date; or

                (iii) if the Registration Statement has been declared effective
     by the Commission and such Registration Statement ceases to be effective
     or usable at any time after the expiration of a Black Out Period until the
     earlier of (A) the Expiration Date and (B) the first date as of which all
     Warrants have been exercised by the Holders thereof (the "Effectiveness
                                                               -------------

                                      14
<PAGE>

     Period"), without being succeeded on the same day immediately by a post-
     ------
     effective amendment to such Registration Statement that cures such failure
     and that is itself immediately declared effective on the same day, (any of
     the foregoing, a "Registration Default"),
                       --------------------

then the Issuer shall pay Liquidated Damages to each Holder in an amount equal
to  $0.03 per week per Warrant held by such Holder for each week or portion
thereof that the Registration Default continues for the first 90-day period
immediately following the occurrence of such Registration Default. This amount
will increase by an additional $0.02 per week per Warrant with respect to each
subsequent 90-day period, up to a maximum amount of Liquidated Damages equal to
$0.07 per week per Warrant. The provision for Liquidated Damages will continue
until such Registration Default has been cured. The Issuer will not be required
to pay Liquidated Damages for more than one Registration Default at any given
time. A Registration Default under clause (i) above shall be cured on the date
that the Registration Statement is filed with the Commission; a Registration
Default under clause (ii) above shall be cured on the date that the Registration
Statement is declared effective by the Commission; a Registration Default under
clause (iii) above shall be cured on the earlier of (A) the date that the post-
effective amendment curing the deficiency in the Registration Statement is
declared effective or (B) the Effectiveness Period expires. Notwithstanding the
foregoing, the Issuer shall not be deemed to have failed to perform its
obligations under clauses (i) through (iii) above by the reason of the failure
of any Holder to provide information regarding itself reasonably requested by
the Issuer or any regulatory agency having jurisdiction over any of the Holders
at least 10 days prior to a Registration Default.

          (b)  Payment of Liquidated Damages.  The Issuer shall notify the
               -----------------------------
Warrant Agent within one Business Day after each and every date on which a
Registration Default occurs (an "Event Date").  Liquidated Damages shall accrue
                                 ----------
from the most recent date to which Liquidated Damages have been paid or, if no
Liquidated Damages have been paid, from the date hereof.  Liquidated Damages
accrued as of January 15 or July 15 of each year (each a "Payment Date") will be
                                                          ------------
payable on such Payment Date.  The Issuer shall pay Liquidated Damages on the
applicable Payment Date to the Persons who are Holders of Warrants at the close
of business on the January 1 or July 1 next preceding the Payment Date.
Liquidated Damages shall be payable at the office of the Warrant Agent or, at
the option of the Issuer, payment of Liquidated Damages may be made by check
mailed to the Holders at their addresses set forth in the register of Holders,
provided that payment by wire transfer of immediately available funds shall be
required with respect to the

                                      15
<PAGE>

Liquidated Damages on all Warrants the Holders of which shall have provided
written wire transfer instructions to the Issuer and the Warrant Agent. Such
payment shall be in such coin or currency of the United States of America as at
the time of payment is legal tender for payment of public and private debts.

SECTION 9. MISCELLANEOUS

           (a)  Remedies.  The Issuer acknowledges and agrees that any failure
                --------
by the Issuer to comply with its obligations under Section 3 hereof may result
in material irreparable injury to the Initial Purchaser or the Holders for which
there is no adequate remedy at law, that it will not be possible to measure
damages for such injuries precisely and that, in the event of any such failure,
the Initial Purchaser or any Holder may obtain such relief as may be required to
specifically enforce the Issuer's obligations under Section 3 hereof. The Issuer
further agrees to waive the defense in any action for specific performance that
a remedy at law would be adequate.

           (b)  No Inconsistent Agreements. The Issuer will not, on or after the
                --------------------------
date of this Agreement, enter into any agreement with respect to its securities
that is inconsistent with the rights granted to the Holders in this Agreement or
otherwise conflicts with the provisions hereof.  Except as set forth in the
Offering Memorandum, the Issuer has not previously entered into any agreement
granting any registration rights with respect to its securities to any Person.
The rights granted to the Holders hereunder do not in any way conflict with and
are not inconsistent with the rights granted to the holders of the Issuer's
securities under any agreement in effect on the date hereof.

           (c)  Amendments and Waivers.  The provisions of this Agreement may
                ----------------------
not be amended, modified or supplemented, and waivers or consents to or
departures from the provisions hereof may not be given unless (i) in the case of
this Section 9(c)(i), the Issuer has obtained the written consent of Holders of
all outstanding Transfer Restricted Securities, and (ii) in the case of all
other provisions hereof, the Issuer has obtained the written consent of Holders
of a majority of the outstanding Transfer Restricted Securities (excluding
Transfer Restricted Securities held by the Issuer or its Affiliates); provided
that this Agreement may be amended without the consent of any Holder in order to
cure any ambiguity or to correct or supplement any provision contained herein
which may be defective or inconsistent with any other provision herein, or to
make any other provisions in regard to matters or questions

                                      16
<PAGE>

arising hereunder which the Issuer may deem necessary or desirable and which
shall not in any way adversely affect any Holder.

          (d)  Third Party Beneficiary.  The Holders shall be third party
               -----------------------
beneficiaries to the agreements granting rights to Holders made hereunder
between the Issuer, on the one hand, and the Initial Purchasers, on the other
hand, and shall have the right to enforce such agreements directly to the extent
they may deem such enforcement necessary or advisable to protect its rights or
the rights of Holders hereunder.

          (e)  Notices.  All notices and other communications provided for or
               -------
permitted hereunder shall be made in writing by hand-delivery, first-class mail
(registered or certified, return receipt requested), telex, telecopier, or air
courier guaranteeing overnight delivery:

               (i)  if to a Holder, at the address set forth on the records of
     the Warrant Agent, with a copy to the Warrant Agent; and

               (ii) if to the Issuer:

                    iPCS, Inc.
                    121 West First Street
                    Suite 200
                    Geneseo, IL 61254
                    Telecopier No.: (309) 945-1650
                    Attention:  President


                    With a copy to:
                    Mayer, Brown & Platt
                    190 South LaSalle Street
                    Chicago, Illinois 60603
                    Telecopier No.: (312) 701-7711
                    Attention:  Paul W. Theiss
                                Robert J. Wild

          All such notices and communications shall be deemed to have been duly
given:  at the time delivered by hand, if personally delivered; five Business
Days after being deposited in the mail, postage prepaid, if mailed; when receipt
acknowledged, if

                                      17
<PAGE>

telecopied; and on the next Business Day, if timely delivered to an air courier
guaranteeing overnight delivery.

          Copies of all such notices, demands or other communications shall be
concurrently delivered by the Person giving the same to the Warrant Agent at the
address specified in Warrant Agreement.

          (f)  Successors and Assigns.  This Agreement shall inure to the
               ----------------------
benefit of and be binding upon the successors and assigns of each of the
parties, including, without limitation, and without the need for an express
assignment, subsequent Holders; provided that nothing herein shall be deemed to
permit any assignment, transfer or other disposition of Transfer Restricted
Securities in violation of the terms hereof or of the Purchase Agreement or the
Warrant Agreement. If any transferee of any Holder shall acquire Transfer
Restricted Securities in any manner, whether by operation of law or otherwise,
such Transfer Restricted Securities shall be held subject to all of the terms of
this Agreement, and by taking and holding such Transfer Restricted Securities
such Person shall be conclusively deemed to have agreed to be bound by and to
perform all of the terms and provisions of this Agreement, including the
restrictions on resale set forth in this Agreement and, if applicable, the
Purchase Agreement or Warrant Agreement, as the case may be, and such Person
shall be entitled to receive the benefits hereof.

          (g)  Counterparts.  This Agreement may be executed in any number of
               ------------
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

          (h)  Headings.  The headings in this Agreement are for convenience of
               --------
reference only and shall not limit or otherwise affect the meaning hereof.

          (i)  Governing Law.  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED
               -------------
IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO THE
CONFLICT OF LAW RULES THEREOF.

          (j)  Severability.  In the event that any one or more of the
               ------------
provisions contained herein, or the application thereof in any circumstance, is
held invalid, illegal or unenforceable, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions contained herein shall not be affected or impaired thereby.

          (k)  Entire Agreement.  This Agreement is intended by the parties as a
               ----------------
final expression of their agreement and intended to be a complete and exclusive

                                      18
<PAGE>

statement of the agreement and understanding of the parties hereto in respect of
the subject matter contained herein.  There are no restrictions, promises,
warranties or undertakings, other than those set forth or referred to herein
with respect to the registration rights granted with respect to the Transfer
Restricted Securities.  This Agreement supersedes all prior agreements and
understandings between the parties with respect to such subject matter.


                 [remainder of page intentionally left blank]

                                      19
<PAGE>

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



                         iPCS, INC.


                         By: /s/ Timothy M. Yager
                             -------------------------
                             Name:  Timothy M. Yager
                             Title: President and Chief
                                    Executive Officer



DONALDSON, LUFKIN & JENRETTE
  SECURITIES CORPORATION
TD SECURITIES (USA) INC.


By:  Donaldson, Lufkin & Jenrette
       Securities Corporation


     By: /s/ David P. Costanzo
         -------------------------------
         Name:  David P. Costanzo
         Title: Senior Vice President