<PAGE>

                                                                    Exhibit 4.15

THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE HEREOF HAVE
NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
"SECURITIES ACT") OR ANY STATE SECURITIES LAWS AND MAY NOT BE SOLD, TRANSFERRED
OR OTHERWISE DISPOSED OF UNLESS REGISTERED UNDER THE SECURITIES ACT AND UNDER
APPLICABLE STATE SECURITIES LAWS OR SPEEDCOM WIRELESS CORPORATION SHALL HAVE
RECEIVED AN OPINION OF ITS COUNSEL THAT REGISTRATION OF SUCH SECURITIES UNDER
THE SECURITIES ACT AND UNDER THE PROVISIONS OF APPLICABLE STATE SECURITIES LAWS
IS NOT REQUIRED.


                              WARRANT TO PURCHASE

                            SHARES OF COMMON STOCK

                                      OF

                         Speedcom Wireless Corporation


                             Expires June 11, 2006

No.: W-4                                                Number of Shares: 73,333
Date of Issuance: June 11, 2001


     FOR VALUE RECEIVED, subject to the provisions hereinafter set forth, the
undersigned, Speedcom Wireless Corporation, a Delaware corporation (together
with its successors and assigns, the "Issuer"), hereby certifies that Bruce
                                      ------
Sanguinetti or his registered assigns is entitled to subscribe for and purchase,
during the period specified in this Warrant, up to Seventy Three Thousand Three
Hundred Thirty Three (73,333) shares (subject to adjustment as hereinafter
provided) of the duly authorized, validly issued, fully paid and non-assessable
Common Stock of the Issuer, at an exercise price per share equal to the Warrant
Price then in effect, subject, however, to the provisions and upon the terms and
conditions hereinafter set forth. Capitalized terms used in this Warrant and not
otherwise defined herein shall have the respective meanings specified in Section
9 hereof.

     1.  Term.  The right to subscribe for and purchase shares of Warrant Stock
         ----
represented hereby shall commence on the date of issuance of this Warrant and
shall expire at 5:00 p.m., eastern time, on June 11, 2006 (such period being the
"Term").
 ----

     2.  Method of Exercise Payment; Issuance of New Warrant; Transfer and
         -----------------------------------------------------------------
         Exchange.
         --------

     (a) Time of Exercise. The purchase rights represented by this Warrant may
         ----------------
be exercised in whole or in part at any time and from time to time during the
Term.

                                      -1-
<PAGE>

     (b) Method of Exercise. The Holder hereof may exercise this Warrant, in
         ------------------
whole or in part, by the surrender of this Warrant (with the exercise form
attached hereto duly executed) at the principal office of the Issuer, and by the
payment to the Issuer of an amount of consideration therefor equal to the
Warrant Price in effect on the date of such exercise multiplied by the number of
shares of Warrant Stock with respect to which this Warrant is then being
exercised, payable at such Holder's election (i) by certified or official bank
check or by wire transfer to an account designated by the Issuer, (ii)
commencing on the first anniversary of the date of issuance, by "cashless
exercise" by surrender to the Issuer for cancellation of a portion of this
Warrant representing that number of unissued shares of Warrant Stock which is
equal to the quotient obtained by dividing (A) the product obtained by
multiplying the Warrant Price by the number of shares of Warrant Stock being
purchased upon such exercise by (B) the Per Share Market Value as of the date of
such exercise, or (iii) commencing on the first anniversary of the date of
issuance, by a combination of the foregoing methods of payment selected by the
Holder of this Warrant. In any case where the consideration payable upon such
exercise is being paid in whole or in part pursuant to the provisions of clause
(ii) of this subsection (b), such exercise shall be accompanied by written
notice from the Holder of this Warrant specifying the manner of payment thereof
and containing a calculation showing the number of shares of Warrant Stock with
respect to which rights are being surrendered thereunder and the net number of
shares to be issued after giving effect to such surrender.

     (c) Issuance of Stock Certificates. In the event of any exercise of the
         ------------------------------
rights represented by this Warrant in accordance with and subject to the terms
and conditions hereof, (i) certificates for the shares of Warrant Stock so
purchased shall be dated the date of such exercise and delivered to the Holder
hereof within a reasonable time, not exceeding three (3) Trading Days after such
exercise, and the Holder hereof shall be deemed for all purposes to be the
Holder of the shares of Warrant Stock so purchased as of the date of such
exercise, and (ii) unless this Warrant has expired, a new Warrant representing
the number of shares of Warrant Stock, if any, with respect to which this
Warrant shall not then have been exercised (less any amount thereof which shall
have been canceled in payment or partial payment of the Warrant Price as
hereinabove provided) shall also be issued to the Holder hereof at the Issuer's
expense within such time.

     (d) Transferability of Warrant. Subject to Section 2(e), this Warrant may
         --------------------------
be transferred by a Holder without the consent of the Issuer. If transferred
pursuant to this paragraph and subject to the provisions of subsection (e) of
this Section 2, this Warrant may be transferred on the books of the Issuer by
the Holder hereof in person or by duly authorized attorney, upon surrender of
this Warrant at the principal office of the Issuer, properly endorsed (by the
Holder executing an assignment in the form attached hereto) and upon payment of
any necessary transfer tax or other governmental charge imposed upon such
transfer. This Warrant is exchangeable at the principal office of the Issuer for
Warrants for the purchase of the same aggregate number of shares of Warrant
Stock, each new Warrant to represent the right to purchase such number of shares
of Warrant Stock as the Holder hereof shall designate at the time of such
exchange. All Warrants issued on transfers or exchanges shall be dated the
Original Issue Date and shall be identical with this Warrant except as to the
number of shares of Warrant Stock issuable pursuant hereto.

                                      -2-
<PAGE>

     (e) Compliance with Securities Laws.
         --------------------------------

         (i)    The Holder of this Warrant, by acceptance hereof, acknowledges
     that this Warrant or the shares of Warrant Stock to be issued upon exercise
     hereof are being acquired solely for the Holder's own account and not as a
     nominee for any other party, and for investment, and that the Holder will
     not offer, sell or otherwise dispose of this Warrant or any shares of
     Warrant Stock to be issued upon exercise hereof except pursuant to an
     effective registration statement, or an exemption from registration, under
     the Securities Act and any applicable state securities laws.

         (ii)   Except as provided in paragraph (iii) below, this Warrant and
     all certificates representing shares of Warrant Stock issued upon exercise
     hereof shall be stamped or imprinted with a legend in substantially the
     following form:

         THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE
         HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
         AMENDED (THE "SECURITIES ACT") OR ANY STATE SECURITIES LAWS AND MAY NOT
         BE SOLD, TRANSFERRED OR OTHERWISE DISPOSED OF UNLESS REGISTERED UNDER
         THE SECURITIES ACT AND UNDER APPLICABLE STATE SECURITIES LAWS OR
         SPEEDCOM WIRELESS CORPORATION SHALL HAVE RECEIVED AN OPINION OF ITS
         COUNSEL THAT REGISTRATION OF SUCH SECURITIES UNDER THE SECURITIES ACT
         AND UNDER THE PROVISIONS OF APPLICABLE STATE SECURITIES LAWS IS NOT
         REQUIRED.

         (iii)  The restrictions imposed by this subsection (e) upon the
     transfer of this Warrant or the shares of Warrant Stock to be purchased
     upon exercise hereof shall terminate (A) when such securities shall have
     been resold pursuant to an effective registration statement under the
     Securities Act, (B) upon the Issuer's receipt of an opinion of counsel, in
     form and substance reasonably satisfactory to the Issuer, addressed to the
     Issuer to the effect that such restrictions are no longer required to
     ensure compliance with the Securities Act and state securities laws or (C)
     upon the Issuer's receipt of other evidence reasonably satisfactory to the
     Issuer that such registration and qualification under the Securities Act
     and state securities laws are not required. Whenever such restrictions
     shall cease and terminate as to any such securities, the Holder thereof
     shall be entitled to receive from the Issuer (or its transfer agent and
     registrar), without expense (other than applicable transfer taxes, if any),
     new Warrants (or, in the case of shares of Warrant Stock, new stock
     certificates) of like tenor not bearing the applicable legend required by
     paragraph (ii) above relating to the Securities Act and state securities
     laws.

     (f) Continuing Rights of Holder.  The Issuer will, at the time of or at any
         ---------------------------
time after each exercise of this Warrant, upon the request of the Holder hereof,
acknowledge in writing the

                                      -3-
<PAGE>

extent, if any, of its continuing obligation to afford to such Holder all rights
to which such Holder shall continue to be entitled after such exercise in
accordance with the terms of this Warrant, provided that if any such Holder
                                           --------
shall fail to make any such request, the failure shall not affect the continuing
obligation of the Issuer to afford such rights to such Holder.

     3.  Stock Fully Paid; Reservation and Listing of Shares; Covenants.
         ---------------------------------------------------------------

     (a) Stock Fully Paid.  The Issuer represents, warrants, covenants and
         ----------------
agrees that all shares of Warrant Stock which may be issued upon the exercise of
this Warrant or otherwise hereunder will, upon issuance, be duly authorized,
validly issued, fully paid and non-assessable and free from all taxes, liens and
charges created by or through Issuer. The Issuer further covenants and agrees
that during the period within which this Warrant may be exercised, the Issuer
will at all times have authorized and reserved for the purpose of the issue upon
exercise of this Warrant a sufficient number of shares of Common Stock to
provide for the exercise of this Warrant.

     (b) Reservation. If any shares of Common Stock required to be reserved for
         -----------
issuance upon exercise of this Warrant or as otherwise provided hereunder
require registration or qualification with any governmental authority under any
federal or state law before such shares may be so issued, the Issuer will in
good faith use its best efforts as expeditiously as possible at its expense to
cause such shares to be duly registered or qualified. If the Issuer shall list
any shares of Common Stock on any securities exchange or market it will, at its
expense, list thereon, maintain and increase when necessary such listing, of,
all shares of Warrant Stock from time to time issued upon exercise of this
Warrant or as otherwise provided hereunder, and, to the extent permissible under
the applicable securities exchange rules, all unissued shares of Warrant Stock
which are at any time issuable hereunder, so long as any shares of Common Stock
shall be so listed. The Issuer will also so list on each securities exchange or
market, and will maintain such listing of, any other securities which the Holder
of this Warrant shall be entitled to receive upon the exercise of this Warrant
if at the time any securities of the same class shall be listed on such
securities exchange or market by the Issuer.

     (c) Covenants. The Issuer shall not by any action including, without
         ---------
limitation, amending the Certificate of Incorporation or the by-laws of the
Issuer, or through any reorganization, transfer of assets, consolidation,
merger, dissolution, issue or sale of securities or any other action, avoid or
seek to avoid the observance or performance of any of the terms of this Warrant,
but will at all times in good faith assist in the carrying out of all such terms
and in the taking of all such actions as may be necessary or appropriate to
protect the rights of the Holder hereof against dilution (to the extent
specifically provided herein) or impairment. Without limiting the generality of
the foregoing, the Issuer will (i) not permit the par value, if any, of its
Common Stock to exceed the then effective Warrant Price, (ii) not amend or
modify any provision of the Certificate of Incorporation or by-laws of the
Issuer in any manner that would adversely affect in any way the powers,
preferences or relative participating, optional or other special rights of the
Common Stock or which would adversely affect the rights of the Holders of the
Warrants, (iii) take all such action as may be reasonably necessary in order
that the Issuer may validly and legally issue fully paid and nonassessable
shares of Common Stock, free and clear of any liens, claims, encumbrances and
restrictions (other than as provided herein) upon the

                                      -4-
<PAGE>

exercise of this Warrant, and (iv) use its best efforts to obtain all such
authorizations, exemptions or consents from any public regulatory body having
jurisdiction thereof as may be reasonably necessary to enable the Issuer to
perform its obligations under this Warrant.

     (d) Loss, Theft, Destruction of Warrants.  Upon receipt of evidence
         ------------------------------------
satisfactory to the Issuer of the ownership of and the loss, theft, destruction
or mutilation of any Warrant and, in the case of any such loss, theft or
destruction, upon receipt of indemnity or security satisfactory to the Issuer
or, in the case of any such mutilation, upon surrender and cancellation of such
Warrant, the Issuer will make and deliver, in lieu of such lost, stolen,
destroyed or mutilated Warrant, a new Warrant of like tenor and representing the
right to purchase the same number of shares of Common Stock.

     (e) Registration Rights. The Warrrant Stock of the Issuer shall carry
         -------------------
standard piggy-back registration rights on any registration statement filed by
the Issuer under the Securities Act of 1933, as amended.

     4.  Adjustment of Warrant Price and Warrant Share Number.  The number of
         ----------------------------------------------------
shares of Common Stock for which this Warrant is exercisable, and the price at
which such shares may be purchased upon exercise of this Warrant, shall be
subject to adjustment from time to time as set forth in this Section 4. The
Issuer shall give the Holder notice of any event described below which requires
an adjustment pursuant to this Section 4 in accordance with Section 5.

     (a) Recapitalization, Reorganization, Reclassification, Consolidation,
         ------------------------------------------------------------------
         Merger or Sale.
         --------------

         (i)    In case the Issuer after the Original Issue Date shall do any of
     the following (each, a "Triggering Event"): (a) consolidate with or merge
                             ----------------
     into any other Person and the Issuer shall not be the continuing or
     surviving corporation of such consolidation or merger, or (b) permit any
     other Person to consolidate with or merge into the Issuer and the Issuer
     shall be the continuing or surviving Person but, in connection with such
     consolidation or merger, any Capital Stock of the Issuer shall be changed
     into or exchanged for Securities of any other Person or cash or any other
     property, or (c) transfer all or substantially all of its properties or
     assets to any other Person, or (d) effect a capital reorganization or
     reclassification of its Capital Stock, then, and in the case of each such
     Triggering Event, proper provision shall be made so that, upon the basis
     and the terms and in the manner provided in this Warrant, the Holder of
     this Warrant shall be entitled (x) upon the exercise hereof at any time
     after the consummation of such Triggering Event, to the extent this Warrant
     is not exercised prior to such Triggering Event, to receive at the Warrant
     Price in effect at the time immediately prior to the consummation of such
     Triggering Event in lieu of the Common Stock issuable upon such exercise of
     this Warrant prior to such Triggering Event, the Securities, cash and
     property to which such Holder would have been entitled upon the
     consummation of such Triggering Event if such Holder had exercised the
     rights represented by this Warrant immediately prior thereto, subject to
     adjustments (subsequent to such corporate action) as nearly equivalent as
     possible to the adjustments provided for elsewhere in this Section 4 or (y)
     to sell this Warrant (or, at such Holder's election, a portion hereof)
     concurrently with the Triggering Event to the Person continuing after or
     surviving such Triggering Event, or to the Issuer

                                      -5-
<PAGE>

     (if Issuer is the continuing or surviving Person) at a sales price equal to
     the amount of cash, property and/or Securities to which a holder of the
     number of shares of Common Stock which would otherwise have been delivered
     upon the exercise of this Warrant would have been entitled upon the
     effective date or closing of any such Triggering Event (the "Event
                                                                  -----
     Consideration"), less the amount or portion of such Event Consideration
     -------------
     having a fair value equal to the aggregate Warrant Price applicable to this
     Warrant or the portion hereof so sold.

         (ii)   Notwithstanding anything contained in this Warrant to the
     contrary, the Issuer will not effect any Triggering Event unless, prior to
     the consummation thereof, each Person (other than the Issuer) which may be
     required to deliver any Securities, cash or property upon the exercise of
     this Warrant as provided herein shall assume, by written instrument
     delivered to, and reasonably satisfactory to, the Holder of this Warrant,
     (A) the obligations of the Issuer under this Warrant (and if the Issuer
     shall survive the consummation of such Triggering Event, such assumption
     shall be in addition to, and shall not release the Issuer from, any
     continuing obligations of the Issuer under this Warrant) and (B) the
     obligation to deliver to such Holder such shares of Securities, cash or
     property as, in accordance with the foregoing provisions of this subsection
     (a), such Holder shall be entitled to receive, and such Person shall have
     similarly delivered to such Holder an opinion of counsel for such Person,
     which counsel shall be reasonably satisfactory to such Holder, stating that
     this Warrant shall thereafter continue in full force and effect and the
     terms hereof (including, without limitation, all of the provisions of this
     subsection (a)) shall be applicable to the Securities, cash or property
     which such Person may be required to deliver upon any exercise of this
     Warrant or the exercise of any rights pursuant hereto.

         (iii)  If with respect to any Triggering Event, the Holder of this
     Warrant has exercised its right as provided in clause (y) of subparagraph
     (i) of this subsection (a) to sell this Warrant or a portion thereof, the
     Issuer agrees that as a condition to the consummation of any such
     Triggering Event the Issuer shall secure such right of Holder to sell this
     Warrant to the Person continuing after or surviving such Triggering Event
     and the Issuer shall not effect any such Triggering Event unless upon or
     prior to the consummation thereof the amounts of cash, property and/or
     Securities required under such clause (y) are delivered to the Holder of
     this Warrant. The obligation of the Issuer to secure such right of the
     Holder to sell this Warrant shall be subject to such Holder's cooperation
     with the Issuer, including, without limitation, the giving of customary
     representations and warranties to the purchaser in connection with any such
     sale. Prior notice of any Triggering Event shall be given to the Holder of
     this Warrant in accordance with Section 13 hereof.

     (b) Stock Dividends, Subdivisions and Combinations. If at any time the
         ----------------------------------------------
         Issuer shall:

                (i)   take a record of the holders of its Common Stock for the
     purpose of entitling them to receive a dividend payable in, or other
     distribution of, Additional Shares of Common Stock,

                                      -6-
<PAGE>

                (ii)  subdivide its outstanding shares of Common Stock into a
     larger number of shares of Common Stock, or

                (iii) combine its outstanding shares of Common Stock into a
     smaller number of shares of Common Stock,

then (1) the number of shares of Common Stock for which this Warrant is
exercisable immediately after the occurrence of any such event shall be adjusted
to equal the number of shares of Common Stock which a record holder of the same
number of shares of Common Stock for which this Warrant is exercisable
immediately prior to the occurrence of such event would own or be entitled to
receive after the happening of such event, and (2) the Warrant Price then in
effect shall be adjusted to equal (A) the Warrant Price then in effect
multiplied by the number of shares of Common Stock for which this Warrant is
exercisable immediately prior to the adjustment divided by (B) the number of
shares of Common Stock for which this Warrant is exercisable immediately after
such adjustment.

     (c) Certain Other Distributions.  If at any time the Issuer shall take a
         ---------------------------
record of the holders of its Common Stock for the purpose of entitling them to
receive any dividend or other distribution of:

                (i)   cash (other than a cash dividend payable out of earnings
     or earned surplus legally available for the payment of dividends under the
     laws of the jurisdiction of incorporation of the Issuer),

                (ii)  any evidences of its indebtedness, any shares of stock of
     any class or any other securities or property of any nature whatsoever
     (other than cash, Common Stock Equivalents or Additional Shares of Common
     Stock), or

                (iii) any warrants or other rights to subscribe for or purchase
     any evidences of its indebtedness, any shares of stock of any class or any
     other securities or property of any nature whatsoever (other than cash,
     Common Stock Equivalents or Additional Shares of Common Stock),

then (1) the number of shares of Common Stock for which this Warrant is
exercisable shall be adjusted to equal the product of the number of shares of
Common Stock for which this Warrant is exercisable immediately prior to such
adjustment multiplied by a fraction (A) the numerator of which shall be the Per
Share Market Value of Common Stock at the date of taking such record and (B) the
denominator of which shall be such Per Share Market Value minus the amount
allocable to one share of Common Stock of any such cash so distributable and of
the fair value (as determined in good faith by the Board of Directors of the
Issuer and supported by an opinion from an investment banking firm of recognized
national standing acceptable to the Holder) of any and all such evidences of
indebtedness, shares of stock, other securities or property or warrants or other
subscription or purchase rights so distributable, and (2) the Warrant Price then
in effect shall be adjusted to equal (A) the Warrant Price then in effect
multiplied by the number of shares of Common Stock for which this Warrant is
exercisable immediately prior to the adjustment divided by (B) the number of
shares of Common Stock for which this Warrant is

                                      -7-
<PAGE>

exercisable immediately after such adjustment. A reclassification of the Common
Stock (other than a change in par value, or from par value to no par value or
from no par value to par value) into shares of Common Stock and shares of any
other class of stock shall be deemed a distribution by the Issuer to the holders
of its Common Stock of such shares of such other class of stock within the
meaning of this Section 4(c) and, if the outstanding shares of Common Stock
shall be changed into a larger or smaller number of shares of Common Stock as a
part of such reclassification, such change shall be deemed a subdivision or
combination, as the case may be, of the outstanding shares of Common Stock
within the meaning of Section 4(b).

     (d) Issuance of Additional Shares of Common Stock.
         ---------------------------------------------

         (i)    In the event the Issuer, shall, at any time, from time to time,
issue or sell any shares of Common Stock (including Treasury Shares) for a
consideration per share less than the Warrant Price then in effect for the
Warrant immediately prior to the time of such issue or sale, then, forthwith
upon such issue or sale, the Warrant Price then in effect for the Warrants shall
be reduced to a price equal to the consideration per share paid for such Common
Stock and the number of shares of Common Stock for which this Warrant is
exercisable shall be increased by the product of the number of shares of Common
Stock for which this Warrant is exercisable immediately prior to such issuance
or sale multiplied by the Dilution Percentage. "Dilution Percentage" shall mean
the percentage by which the Warrant Price then in effect is reduced pursuant to
this Section 4(d).

         (ii)   If at any time the Issuer shall at any time issue or sell any
Additional Shares of Common Stock in exchange for consideration in an amount per
Additional Share of Common Stock less than the Per Share Market Value at the
time the Additional Shares of Common Stock are issued or sold, then, forthwith
upon such issue or sale, the Warrant Price then in effect for the Warrants shall
be reduced by the product of the Warrant Price then in effect multiplied by the
Market Dilution Percentage and the number of shares of Common Stock for which
this Warrant is exercisable shall be increased by the product of the number of
shares of Common Stock for which this Warrant is exercisable immediately prior
to such issuance or sale multiplied by the Market Dilution Percentage. "Market
Dilution Percentage" shall mean the percentage by which such issuance or sale is
below the lesser of the Per Share Market Value or the per share market value of
the Common Stock as calculated pursuant to the terms of any other financings of
the Company.

         (iii)  If at any time the Issuer shall issue or sell any Additional
Shares of Common Stock in exchange for consideration in an amount per Additional
Share of Common Stock which is less than the Warrant Price or the Per Share
Market Value at the time the Additional Shares of Common Stock are issued or
sold, the adjustment required under Section 4(d) shall be made in accordance
with the formula in paragraph (i) or (ii) above which results in the lower
Warrant Price following such adjustment. The provisions of paragraphs (i) and
(ii) of Section 4(d) shall not apply to any issuance of Additional Shares of
Common Stock for which an adjustment is provided under Section 4(b) or 4(c). No
adjustment of the number of shares of Common Stock for which this Warrant shall
be exercisable shall be made under paragraph (i) or (ii) of Section 4(d) upon
the issuance of any Additional Shares of Common Stock which are issued pursuant
to the exercise of any warrants or other subscription or purchase rights or

                                      -8-
<PAGE>

pursuant to the exercise of any conversion or exchange rights in any Common
Stock Equivalents, if any such adjustment shall previously have been made upon
the issuance of such warrants or other rights or upon the issuance of such
Common Stock Equivalents (or upon the issuance of any warrant or other rights
therefor) pursuant to Section 4(e) or Section 4(f).

     (e) Issuance of Warrants or Other Rights. If at any time the Issuer shall
         ------------------------------------
take a record of the Holders of its Common Stock for the purpose of entitling
them to receive a distribution of, or shall in any manner (whether directly or
by assumption in a merger in which the Issuer is the surviving corporation)
issue or sell, any Common Stock Equivalents (or issue any warrant or other
rights therefor), whether or not the rights to exchange or convert thereunder
are immediately exercisable, and the price per share for which Common Stock is
issuable upon the exercise of such Common Stock Equivalents (or any warrant or
other rights therefor) shall be less than the Warrant Price in effect
immediately prior to the time of such issue or sale, then the number of shares
for which this Warrant is exercisable and the Warrant Price then in effect shall
be adjusted as provided in Section 4(d) on the basis that the maximum number of
Additional Shares of Common Stock issuable pursuant to all such Common Stock
Equivalents (or upon the issuance of any warrant or other rights therefor) shall
be deemed to have been issued and outstanding and the Issuer shall have received
all of the consideration payable therefor, if any, as of the date of the actual
issuance of such warrants or other rights. No adjustments of the Warrant Price
then in effect or the number of Warrant Shares for which this Warrant is
exercisable shall be made upon the actual issue of such Common Stock or of such
Common Stock Equivalents upon exercise of such warrants or other rights or upon
the actual issue of such Common Stock upon such conversion or exchange of such
Common Stock Equivalents.

     (f) Issuance of Common Stock Equivalents. If at any time the Issuer shall
         ------------------------------------
take a record of the Holders of its Common Stock for the purpose of entitling
them to receive a distribution of, or shall in any manner (whether directly or
by assumption in a merger in which the Issuer is the surviving corporation)
issue or sell, any Common Stock Equivalents, whether or not the rights to
exchange or convert thereunder are immediately exercisable, and the price per
share for which Common Stock is issuable upon such conversion or exchange shall
be less than the Warrant Price in effect immediately prior to the time of such
issue or sale, then the number of shares of Common Stock for which this Warrant
is exercisable and the Warrant Price then in effect shall be adjusted as
provided in Section 4(d) on the basis that the maximum number of Additional
Shares of Common Stock necessary to effect the conversion or exchange of all
such Common Stock Equivalents shall be deemed to have been issued and
outstanding and the Issuer shall have received all of the consideration payable
therefor, if any, as of the date of actual issuance of such Common Stock
Equivalents. No further adjustment of the number of shares of Common Stock for
which this Warrant is exercisable and the Warrant Price then in effect shall be
made under this Section 4(f) upon the issuance of any Common Stock Equivalents
which are issued pursuant to the exercise of any warrants or other subscription
or purchase rights therefor, if any such adjustment shall previously have been
made upon the issuance of such warrants or other rights pursuant to Section
4(e). No further adjustments of the number of shares of Common Stock for which
this Warrant is exercisable and the Warrant Price then in effect shall be made
upon the actual issue of such Common Stock upon conversion or exchange of such
Common Stock Equivalents.

                                      -9-
<PAGE>

     (g) Superseding Adjustment. If, at any time after any adjustment of the
         ----------------------
number of shares of Common Stock for which this Warrant is exercisable and the
Warrant Price then in effect shall have been made pursuant to Section 4(e) or
Section 4(f) as the result of any issuance of warrants, other rights or Common
Stock Equivalents, and (i) such warrants or other rights, or the right of
conversion or exchange in such other Common Stock Equivalents, shall expire, and
all or a portion of such warrants or other rights, or the right of conversion or
exchange with respect to all or a portion of such other Common Stock
Equivalents, as the case may be shall not have been exercised, or (ii) the
consideration per share for which shares of Common Stock are issuable pursuant
to such Common Stock Equivalents, shall be increased solely by virtue of
provisions therein contained for an automatic increase in such consideration per
share upon the occurrence of a specified date or event, then for each
outstanding Warrant such previous adjustment shall be rescinded and annulled and
the Additional Shares of Common Stock which were deemed to have been issued by
virtue of the computation made in connection with the adjustment so rescinded
and annulled shall no longer be deemed to have been issued by virtue of such
computation. Upon the occurrence of an event set forth in this Section 4(g)
above, there shall be a recomputation made of the effect of such Common Stock
Equivalents on the basis of: (i) treating the number of Additional Shares of
Common Stock or other property, if any, theretofore actually issued or issuable
pursuant to the previous exercise of any such warrants or other rights or any
such right of conversion or exchange, as having been issued on the date or dates
of any such exercise and for the consideration actually received and receivable
therefor, and (ii) treating any such Common Stock Equivalents which then remain
outstanding as having been granted or issued immediately after the time of such
increase of the consideration per share for which shares of Common Stock or
other property are issuable under such Common Stock Equivalents; whereupon a new
adjustment of the number of shares of Common Stock for which this Warrant is
exercisable and the Warrant Price then in effect shall be made, which new
adjustment shall supersede the previous adjustment so rescinded and annulled.

     (h) Purchase of Common Stock by the Issuer. If the Issuer at any time
         --------------------------------------
while this Warrant is outstanding shall, directly or indirectly through a
Subsidiary or otherwise, purchase, redeem or otherwise acquire any shares of
Common Stock at a price per share greater than the Per Share Market Value, then
the Warrant Price upon each such purchase, redemption or acquisition shall be
adjusted to that price determined by multiplying such Warrant Price by a
fraction (i) the numerator of which shall be the number of shares of Common
Stock outstanding immediately prior to such purchase, redemption or acquisition
minus the number of shares of Common Stock which the aggregate consideration for
the total number of such shares of Common Stock so purchased, redeemed or
acquired would purchase at the Per Share Market Value; and (ii) the denominator
of which shall be the number of shares of Common Stock outstanding immediately
after such purchase, redemption or acquisition. For the purposes of this
subsection (h), the date as of which the Per Share Market Price shall be
computed shall be the earlier of (x) the date on which the Issuer shall enter
into a firm contract for the purchase, redemption or acquisition of such Common
Stock, or (y) the date of actual purchase, redemption or acquisition of such
Common Stock. For the purposes of this subsection (h), a purchase, redemption or
acquisition of a Common Stock Equivalent shall be deemed to be a purchase of the
underlying Common Stock, and the computation herein required shall be made on
the basis of the full exercise, conversion or exchange of such Common Stock
Equivalent on the date as of

                                      -10-
<PAGE>

which such computation is required hereby to be made, whether or not such Common
Stock Equivalent is actually exercisable, convertible or exchangeable on such
date.

     (i) Other Provisions applicable to Adjustments under this Section. The
         -------------------------------------------------------------
following provisions shall be applicable to the making of adjustments of the
number of shares of Common Stock for which this Warrant is exercisable and the
Warrant Price then in effect provided for in this Section 4:

         (i)    Computation of Consideration. To the extent that any Additional
                ----------------------------
Shares of Common Stock or any Common Stock Equivalents (or any warrants or other
rights therefor) shall be issued for cash consideration, the consideration
received by the Issuer therefor shall be the amount of the cash received by the
Issuer therefor, or, if such Additional Shares of Common Stock or Common Stock
Equivalents are offered by the Issuer for subscription, the subscription price,
or, if such Additional Shares of Common Stock or Common Stock Equivalents are
sold to underwriters or dealers for public offering without a subscription
offering, the initial public offering price (in any such case subtracting any
amounts paid or receivable for accrued interest or accrued dividends and without
taking into account any compensation, discounts or expenses paid or incurred by
the Issuer for and in the underwriting of, or otherwise in connection with, the
issuance thereof). To the extent that such issuance shall be for a consideration
other than cash, then, except as herein otherwise expressly provided, the amount
of such consideration shall be deemed to be the fair value of such consideration
at the time of such issuance as determined in good faith by the Board of
Directors of the Issuer. In case any Additional Shares of Common Stock or any
Common Stock Equivalents (or any warrants or other rights therefor) shall be
issued in connection with any merger in which the Issuer issues any securities,
the amount of consideration therefor shall be deemed to be the fair value, as
determined in good faith by the Board of Directors of the Issuer, of such
portion of the assets and business of the nonsurviving corporation as such Board
in good faith shall determine to be attributable to such Additional Shares of
Common Stock, Common Stock Equivalents, or any warrants or other rights
therefor, as the case may be. The consideration for any Additional Shares of
Common Stock issuable pursuant to any warrants or other rights to subscribe for
or purchase the same shall be the consideration received by the Issuer for
issuing such warrants or other rights plus the additional consideration payable
to the Issuer upon exercise of such warrants or other rights. The consideration
for any Additional Shares of Common Stock issuable pursuant to the terms of any
Common Stock Equivalents shall be the consideration received by the Issuer for
issuing warrants or other rights to subscribe for or purchase such Common Stock
Equivalents, plus the consideration paid or payable to the Issuer in respect of
the subscription for or purchase of such Common Stock Equivalents, plus the
additional consideration, if any, payable to the Issuer upon the exercise of the
right of conversion or exchange in such Common Stock Equivalents. In case of the
issuance at any time of any Additional Shares of Common Stock or Common Stock
Equivalents in payment or satisfaction of any dividends upon any class of stock
other than Common Stock, the Issuer shall be deemed to have received for such
Additional Shares of Common Stock or Common Stock Equivalents a consideration
equal to the amount of such dividend so paid or satisfied.

         (ii)   When Adjustments to Be Made. The adjustments required by this
                ---------------------------
Section 4 shall be made whenever and as often as any specified event requiring
an adjustment shall

                                      -11-
<PAGE>

occur, except that any adjustment of the number of shares of Common Stock for
which this Warrant is exercisable that would otherwise be required may be
postponed (except in the case of a subdivision or combination of shares of the
Common Stock, as provided for in Section 4(b)) up to, but not beyond the date of
exercise if such adjustment either by itself or with other adjustments not
previously made adds or subtracts less than one percent (1%) of the shares of
Common Stock for which this Warrant is exercisable immediately prior to the
making of such adjustment. Any adjustment representing a change of less than
such minimum amount (except as aforesaid) which is postponed shall be carried
forward and made as soon as such adjustment, together with other adjustments
required by this Section 4 and not previously made, would result in a minimum
adjustment or on the date of exercise. For the purpose of any adjustment, any
specified event shall be deemed to have occurred at the close of business on the
date of its occurrence.

         (iii)  Fractional Interests. In computing adjustments under this
                --------------------
Section 4, fractional interests in Common Stock shall be taken into account to
the nearest one one-hundredth (1/100/th/) of a share.

         (iv)   When Adjustment Not Required. If the Issuer shall take a record
                ----------------------------
of the holders of its Common Stock for the purpose of entitling them to receive
a dividend or distribution or subscription or purchase rights and shall,
thereafter and before the distribution to stockholders thereof, legally abandon
its plan to pay or deliver such dividend, distribution, subscription or purchase
rights, then thereafter no adjustment shall be required by reason of the taking
of such record and any such adjustment previously made in respect thereof shall
be rescinded and annulled. In addition, no adjustment shall be required under
Section 4(d)(i) hereof in the event the Issuer issues or sells Additional Shares
in a transaction whose primary purpose is to establish a relationship with the
recipient thereof for strategic reasons and not to raise capital.

     (j) Form of Warrant after Adjustments. The form of this Warrant need not
         ---------------------------------
be changed because of any adjustments in the Warrant Price or the number and
kind of Securities purchasable upon the exercise of this Warrant.

     (k) Escrow of Warrant Stock. If after any property becomes distributable
         -----------------------
pursuant to this Section 4 by reason of the taking of any record of the holders
of Common Stock, but prior to the occurrence of the event for which such record
is taken, and the Holder exercises this Warrant, any shares of Common Stock
issuable upon exercise by reason of such adjustment shall be deemed the last
shares of Common Stock for which this Warrant is exercised (notwithstanding any
other provision to the contrary herein) and such shares or other property shall
be held in escrow for the Holder by the Issuer to be issued to the Holder upon
and to the extent that the event actually takes place, upon payment of the
current Warrant Price. Notwithstanding any other provision to the contrary
herein, if the event for which such record was taken fails to occur or is
rescinded, then such escrowed shares shall be cancelled by the Issuer and
escrowed property returned.

     5.  Notice of Adjustments. Whenever the Warrant Price or Warrant Share
         ---------------------
Number shall be adjusted pursuant to Section 4 hereof (for purposes of this
Section 5, each an "adjustment"), the Issuer shall cause its Chief Financial
Officer to prepare and execute a

                                      -12-
<PAGE>

certificate setting forth, in reasonable detail, the event requiring the
adjustment, the amount of the adjustment, the method by which such adjustment
was calculated (including a description of the basis on which the Board made any
determination hereunder), and the Warrant Price and Warrant Share Number after
giving effect to such adjustment, and shall cause copies of such certificate to
be delivered to the Holder of this Warrant promptly after each adjustment. Any
dispute between the Issuer and the Holder of this Warrant with respect to the
matters set forth in such certificate may at the option of the Holder of this
Warrant be submitted to one of the national accounting firms currently known as
the "big five" selected by the Holder, provided that the Issuer shall have ten
                                       --------
(10) days after receipt of notice from such Holder of its selection of such firm
to object thereto, in which case such Holder shall select another such firm and
the Issuer shall have no such right of objection. The firm selected by the
Holder of this Warrant as provided in the preceding sentence shall be instructed
to deliver a written opinion as to such matters to the Issuer and such Holder
within thirty (30) days after submission to it of such dispute. Such opinion
shall be final and binding on the parties hereto. The fees and expenses of such
accounting firm shall be paid by the Issuer.

     6.  Fractional Shares. No fractional shares of Warrant Stock will be
         -----------------
issued in connection with and exercise hereof, but in lieu of such fractional
shares, the Issuer shall make a cash payment therefor equal in amount to the
product of the applicable fraction multiplied by the Per Share Market Value then
in effect.

     7.  Intentionally Omitted.
         ---------------------

     8.  Warrant Exercise Restriction. Notwithstanding anything to the contrary
         ----------------------------
set forth in this Warrant, at no time may a holder of this Warrant exercise this
Warrant, or a portion hereof, if the number of shares of Common Stock to be
issued pursuant to such exercise would exceed, when aggregated with all other
shares of Common Stock owned by such holder at such time, would result in such
holder owning more than 9.99% of all of the Common Stock issued and outstanding
at such time; provided, however, that upon a holder of this Warrant providing
              --------  -------
the Issuer with thirty (30) days notice (pursuant to Section 13 hereof) (the
"Waiver Notice") that such holder would like to waive Section 8 of this Warrant
 -------------
with regard to any or all shares of Common Stock issuable upon exercise of the
Warrant, this Section 8 will be of no force or effect with regard to the number
of shares exercisable pursuant to the Warrant, or the applicable portion
thereof, referenced in the Waiver Notice.

     9.  Definitions. For the purposes of this Warrant, the following terms have
         -----------
the following meanings:

         "Additional Shares of Common Stock" means all shares of Common Stock
         ---------------------------------
     issued by the Issuer after the Original Issue Date, and all shares of Other
     Common, if any, issued by the Issuer after the Original Issue Date, except
     the Warrant Stock.

         "Board" shall mean the Board of Directors of the Issuer.
          -----

         "Capital Stock" means and includes (i) any and all shares, interests,
          -------------
     participations or other equivalents of or interests in (however designated)
     corporate stock, including,

                                      -13-
<PAGE>

     without limitation, shares of preferred or preference stock, (ii) all
     partnership interests (whether general or limited) in any Person which is a
     partnership, (iii) all membership interests or limited liability company
     interests in any limited liability company, and (iv) all equity or
     ownership interests in any Person of any other type.

         "Certificate of Incorporation" means the Certificate of Incorporation
          ----------------------------
     of the Issuer as in effect on the Original Issue Date, and as hereafter
     from time to time amended, modified, supplemented or restated in accordance
     with the terms hereof and thereof and pursuant to applicable law.

         "Common Stock" means the Common Stock, par value $.001 per share, of
          ------------
     the Issuer and any other Capital Stock into which such stock may hereafter
     be changed.

         "Common Stock Equivalent" means any Convertible Security or warrant,
          -----------------------
     option or other right to subscribe for or purchase any Additional Shares of
     Common Stock or any Convertible Security.

         "Convertible Securities" means evidences of Indebtedness, shares of
          ----------------------
     Capital Stock or other Securities which are or may be at any time
     convertible into or exchangeable for Additional Shares of Common Stock. The
     term "Convertible Security" means one of the Convertible Securities.

         "Governmental Authority" means any governmental, regulatory or self-
          ----------------------
     regulatory entity, department, body, official, authority, commission,
     board, agency or instrumentality, whether federal, state or local, and
     whether domestic or foreign.

         "Holders" mean the Persons who shall from time to time own any Warrant.
          -------
     The term "Holder" means one of the Holders.

         "Independent Appraiser" means a nationally recognized or major regional
          ---------------------
     investment banking firm or firm of independent certified public accountants
     of recognized standing (which may be the firm that regularly examines the
     financial statements of the Issuer) that is regularly engaged in the
     business of appraising the Capital Stock or assets of corporations or other
     entities as going concerns, and which is not affiliated with either the
     Issuer or the Holder of any Warrant.

         "Issuer" means Speedcom Wireless Corporation, a Delaware corporation,
          ------
     and its successors.

         "Majority Holders" means at any time the Holders of Warrants
          ----------------
     exercisable for a majority of the shares of Warrant Stock issuable under
     the Warrants at the time outstanding.

         "Nasdaq" means the Nasdaq SmallCap Market.
          ------

         "Original Issue Date" means June 11, 2001.
          -------------------

                                      -14-
<PAGE>

         "OTC Bulletin Board" means the over-the-counter electronic bulletin
          ------------------
         board.

         "Other Common" means any other Capital Stock of the Issuer of any
          ------------
     class which shall be authorized at any time after the date of this Warrant
     (other than Common Stock) and which shall have the right to participate in
     the distribution of earnings and assets of the Issuer without limitation as
     to amount.

         "Person" means an individual, corporation, limited liability company,
          ------
     partnership, joint stock company, trust, unincorporated organization, joint
     venture, Governmental Authority or other entity of whatever nature.

         "Per Share Market Value" means on any particular date (a) the closing
          ----------------------
     bid price per share of the Common Stock on such date on Nasdaq or another
     registered national stock exchange on which the Common Stock is then
     listed, or if there is no such price on such date, then the closing bid
     price on such exchange or quotation system on the date nearest preceding
     such date, or (b) if the Common Stock is not listed then on Nasdaq or any
     registered national stock exchange, the closing bid price for a share of
     Common Stock in the over-the-counter market, as reported by the OTC
     Bulletin Board or in the National Quotation Bureau Incorporated or similar
     organization or agency succeeding to its functions of reporting prices) at
     the close of business on such date, or (c) if the Common Stock is not then
     reported by the OTC Bulletin Board or the National Quotation Bureau
     Incorporated (or similar organization or agency succeeding to its functions
     of reporting prices), then the average of the "Pink Sheet" quotes for the
     relevant conversion period, as determined in good faith by the holder, or
     (d) if the Common Stock is not then publicly traded the fair market value
     of a share of Common Stock as determined by an Independent Appraiser
     selected in good faith by the Majority Holders; provided, however, that the
                                                     --------  -------
     Issuer, after receipt of the determination by such Independent Appraiser,
     shall have the right to select an additional Independent Appraiser, in
     which case, the fair market value shall be equal to the average of the
     determinations by each such Independent Appraiser; and provided, further
                                                            --------  -------
     that all determinations of the Per Share Market Value shall be
     appropriately adjusted for any stock dividends, stock splits or other
     similar transactions during such period. The determination of fair market
     value by an Independent Appraiser shall be based upon the fair market value
     of the Issuer determined on a going concern basis as between a willing
     buyer and a willing seller and taking into account all relevant factors
     determinative of value, and shall be final and binding on all parties. In
     determining the fair market value of any shares of Common Stock, no
     consideration shall be given to any restrictions on transfer of the Common
     Stock imposed by agreement or by federal or state securities laws, or to
     the existence or absence of, or any limitations on, voting rights.

         "Purchase Agreement" means the Note and Warrant Purchase Agreement
          ------------------
     dated as of June 11, 2001 among the Issuer and the investors a party
     thereto.

         "Securities" means any debt or equity securities of the Issuer,
          ----------
     whether now or hereafter authorized, any instrument convertible into or
     exchangeable for Securities or a

                                      -15-
<PAGE>

     Security, and any option, warrant or other right to purchase or acquire any
     Security. "Security" means one of the Securities.

         "Securities Act" means the Securities Act of 1933, as amended, or any
          --------------
     similar federal statute then in effect.

         "Subsidiary" means any corporation at least 50% of whose outstanding
          ----------
     Voting Stock shall at the time be owned directly or indirectly by the
     Issuer or by one or more of its Subsidiaries, or by the Issuer and one or
     more of its Subsidiaries.

         "Term" has the meaning specified in Section 1 hereof.
          ----

         "Trading Day" means (a) a day on which the Common Stock is traded on
          -----------
     Nasdaq, or (b) if the Common Stock is not listed on Nasdaq, a day on which
     the Common Stock is traded on any other registered national stock exchange,
     or (c) if the Common Stock is not traded on any other registered national
     stock exchange, a day on which the Common Stock is traded on the OTC
     Bulletin Board, or (d) if the Common Stock is not traded on the OTC
     Bulletin Board, a day on which the Common Stock is quoted in the over-the-
     counter market as reported by the National Quotation Bureau Incorporated
     (or any similar organization or agency succeeding its functions of
     reporting prices); provided, however, that in the event that the Common
                        --------  -------
     Stock is not listed or quoted as set forth in (a), (b) and (c) hereof, then
     Trading Day shall mean any day except Saturday, Sunday and any day which
     shall be a legal holiday or a day on which banking institutions in the
     State of New York are authorized or required by law or other government
     action to close.

         "Voting Stock" means, as applied to the Capital Stock of any
          ------------
     corporation, Capital Stock of any class or classes (however designated)
     having ordinary voting power for the election of a majority of the members
     of the Board of Directors (or other governing body) of such corporation,
     other than Capital Stock having such power only by reason of the happening
     of a contingency.

         "Warrants" means the Warrants issued and sold pursuant to the Purchase
          --------
     Agreement, including, without limitation, this Warrant, and any other
     warrants of like tenor issued in substitution or exchange for any thereof
     pursuant to the provisions of Section 2(c), 2(d) or 2(e) hereof or of any
     of such other Warrants.

         "Warrant Price" means U.S. $3.25, as such price may be adjusted from
          -------------
     time to time as shall result from the adjustments specified in this
     Warrant, including Section 4 hereto.

         "Warrant Share Number" means at any time the aggregate number of shares
          --------------------
     of Warrant Stock which may at such time be purchased upon exercise of this
     Warrant, after giving effect to all prior adjustments and increases to such
     number made or required to be made under the terms hereof.

                                      -16-
<PAGE>

         "Warrant Stock" means Common Stock issuable upon exercise of any
          -------------
     Warrant or Warrants or otherwise issuable pursuant to any Warrant or
     Warrants.

     10. Other Notices.  In case at any time:
         -------------

                         (A)  the Issuer shall make any distributions to the
                              holders of Common Stock; or

                         (B)  the Issuer shall authorize the granting to all
                              holders of its Common Stock of rights to subscribe
                              for or purchase any shares of Capital Stock of any
                              class or of any Common Stock Equivalents or other
                              rights; or

                         (C)  there shall be any reclassification of the Capital
                              Stock of the Issuer; or

                         (D)  there shall be any capital reorganization by the
                              Issuer; or

                         (E)  there shall be any (i) consolidation or merger
                              involving the Issuer or (ii) sale, transfer or
                              other disposition of all or substantially all of
                              the Issuer's property, assets or business (except
                              a merger or other reorganization in which the
                              Issuer shall be the surviving corporation and its
                              shares of Capital Stock shall continue to be
                              outstanding and unchanged and except a
                              consolidation, merger, sale, transfer or other
                              disposition involving a wholly-owned Subsidiary);
                              or

                         (F)  there shall be a voluntary or involuntary
                              dissolution, liquidation or winding-up of the
                              Issuer or any partial liquidation of the Issuer or
                              distribution to holders of Common Stock;

then, in each of such cases, the Issuer shall give written notice to the Holder
of the date on which (i) the books of the Issuer shall close or a record shall
be taken for such dividend, distribution or subscription rights or (ii) such
reorganization, reclassification, consolidation, merger, disposition,
dissolution, liquidation or winding-up, as the case may be, shall take place.
Such notice also shall specify the date as of which the holders of Common Stock
of record shall participate in such dividend, distribution or subscription
rights, or shall be entitled to exchange their certificates for Common Stock for
securities or other property deliverable upon such reorganization,
reclassification, consolidation, merger, disposition, dissolution, liquidation
or winding-up, as the case may be. Such notice shall be given at least twenty
(20) days prior to the action in question and not less than twenty (20) days
prior to the record date or the date on which the Issuer's transfer books are
closed in respect thereto. The Issuer shall give to the Holder notice of all
meetings and actions by written consent of its stockholders, at the same time in
the same manner as notice of any meetings of stockholders is required to be
given to stockholders who do not waive such notice (or, if such requires no
notice, then two (2) Trading Days written

                                      -17-
<PAGE>

notice thereof describing the matters upon which action is to be taken). The
Holder shall have the right to send two (2) representatives selected by it to
each meeting, who shall be permitted to attend, but not vote at, such meeting
and any adjournments thereof. This Warrant entitles the Holder to receive copies
of all financial and other information distributed or required to be distributed
to the holders of the Common Stock.

     11.  Amendment and Waiver. Any term, covenant, agreement or condition in
          --------------------
this Warrant may be amended, or compliance therewith may be waived (either
generally or in a particular instance and either retroactively or
prospectively), by a written instrument or written instruments executed by the
Issuer and the Majority Holders; provided, however, that no such amendment or
                                 --------  -------
waiver shall reduce the Warrant Share Number, increase the Warrant Price,
shorten the period during which this Warrant may be exercised or modify any
provision of this Section 11 without the consent of the Holder of this Warrant.

     12.  Governing Law. THIS WARRANT SHALL BE GOVERNED BY AND CONSTRUED IN
          -------------
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT GIVING EFFECT TO
PRINCIPLES OF CONFLICTS OF LAW.

     13.  Notices. Any and all notices or other communications or deliveries
          -------
required or permitted to be provided hereunder shall be in writing and shall be
deemed given and effective on the earlier of (i) the date of transmission, if
such notice or communication is delivered via facsimile at the facsimile
telephone number specified for notice prior to 5:00 p.m., eastern time, on a
Trading Day, (ii) the Trading Day after the date of transmission, if such notice
or communication is delivered via facsimile at the facsimile telephone number
specified for notice later than 5:00 p.m., eastern time, on any date and earlier
than 11:59 p.m., eastern time, on such date, (iii) the Trading Day following the
date of mailing, if sent by nationally recognized overnight courier service or
(iv) actual receipt by the party to whom such notice is required to be given.
The addresses for such communications shall be with respect to the Holder of
this Warrant or of Warrant Stock issued pursuant hereto, addressed to such
Holder at its last known address or facsimile number appearing on the books of
the Issuer maintained for such purposes, or with respect to the Issuer,
addressed to:

          Speedcom Wireless Corporation
          1748 Independence Boulevard, D-4
          Sarasota, Florida  34243
          Attention:  Jay Wright, Chief Financial Officer
          Telephone: (941) 358-9283
          Telecopier: (941) 358-6208

                                      -18-
<PAGE>

with copies (which copies shall not constitute notice to the Company) to:

          Foley & Lardner
          One IBM Plaza
          330 N. Wabash Avenue, Suite 3300
          Chicago, Illinois 60611-3608
          Attention:  Edwin D. Mason, Esq.
          Telephone: (312) 755-2532
          Telecopier: (312) 755-1925

Copies of notices to the Holder shall be sent to Jenkens & Gilchrist Parker
Chapin LLP, The Chrysler Building, 405 Lexington Avenue, New York, New York
10174, Attention: Christopher S. Auguste, Esq., facsimile no.: (212) 704-6288.
Any party hereto may from time to time change its address for notices by giving
at least ten (10) days written notice of such changed address to the other party
hereto.

     14.  Warrant Agent. The Issuer may, by written notice to each Holder of
          -------------
this Warrant, appoint an agent having an office in New York, New York for the
purpose of issuing shares of Warrant Stock on the exercise of this Warrant
pursuant to subsection (b) of Section 2 hereof, exchanging this Warrant pursuant
to subsection (d) of Section 2 hereof or replacing this Warrant pursuant to
subsection (d) of Section 3 hereof, or any of the foregoing, and thereafter any
such issuance, exchange or replacement, as the case may be, shall be made at
such office by such agent.

     15.  Remedies. The Issuer stipulates that the remedies at law of the
          --------
Holder of this Warrant in the event of any default or threatened default by the
Issuer in the performance of or compliance with any of the terms of this Warrant
are not and will not be adequate and that, to the fullest extent permitted by
law, such terms may be specifically enforced by a decree for the specific
performance of any agreement contained herein or by an injunction against a
violation of any of the terms hereof or otherwise.

     16.  Successors and Assigns. This Warrant and the rights evidenced hereby
          ----------------------
shall inure to the benefit of and be binding upon the successors and assigns of
the Issuer, the Holder hereof and (to the extent provided herein) the Holders of
Warrant Stock issued pursuant hereto, and shall be enforceable by any such
Holder or Holder of Warrant Stock.

     17.  Modification and Severability. If, in any action before any court or
          -----------------------------
agency legally empowered to enforce any provision contained herein, any
provision hereof is found to be unenforceable, then such provision shall be
deemed modified to the extent necessary to make it enforceable by such court or
agency. If any such provision is not enforceable as set forth in the preceding
sentence, the unenforceability of such provision shall not affect the other
provisions of this Warrant, but this Warrant shall be construed as if such
unenforceable provision had never been contained herein.

     18.  Headings. The headings of the Sections of this Warrant are for
          --------
convenience of reference only and shall not, for any purpose, be deemed a part
of this Warrant.

                                      -19-
<PAGE>

     IN WITNESS WHEREOF, the Issuer has executed this Warrant as of the day and
year first above written.


                              SPEEDCOM WIRELESS CORPORATION



                              By:__________________________________
                                  Name:
                                  Title:

                                      -20-
<PAGE>

                                 EXERCISE FORM

                         SPEEDCOM WIRELESS CORPORATION

The undersigned _______________, pursuant to the provisions of the within
Warrant, hereby elects to purchase _____ shares of Common Stock of Speedcom
Wireless Corporation covered by the within Warrant.

Dated: _________________      Signature  ___________________________

                              Address    _____________________
                                         _____________________


                                  ASSIGNMENT

FOR VALUE RECEIVED, _________________ hereby sells, assigns and transfers unto
__________________ the within Warrant and all rights evidenced thereby and does
irrevocably constitute and appoint _____________, attorney, to transfer the said
Warrant on the books of the within named corporation.

Dated: _________________      Signature  ___________________________

                              Address    _____________________
                                         _____________________


                              PARTIAL ASSIGNMENT

FOR VALUE RECEIVED, _________________ hereby sells, assigns and transfers unto
__________________ the right to purchase _________ shares of Warrant Stock
evidenced by the within Warrant together with all rights therein, and does
irrevocably constitute and appoint ___________________, attorney, to transfer
that part of the said Warrant on the books of the within named corporation.

Dated: _________________      Signature  ___________________________

                              Address    _____________________
                                         _____________________

                          FOR USE BY THE ISSUER ONLY:

This Warrant No. W-_____ canceled (or transferred or exchanged) this _____ day
of ___________, _____, shares of Common Stock issued therefor in the name of
_______________, Warrant No. W-_____ issued for ____ shares of Common Stock in
the name of _______________.

                                      -21-