<PAGE>


                               SILICON VALLEY BANK                EXHIBIT 10.109

                             SECURED PROMISSORY NOTE

$4,000,000                                                    SEPTEMBER 20, 2002

     FOR VALUE RECEIVED, the undersigned (jointly and severally, the "Borrower")
promises to pay to the order of SILICON VALLEY BANK ("Silicon"), at 3003 Tasman
Drive, Santa Clara, California 95054, or at such other address as the holder of
this Note shall direct, the principal sum of FOUR MILLION DOLLARS ($4,000,000),
or such lesser or greater amount as shall be equal to the unpaid balance of the
"Exim Loans" as defined in the Loan and Security Agreement (Exim Program)
between Borrower and Silicon of even date herewith (the "Loan Agreement").

     The principal amount of this Note shall be payable on the date the Loan
Agreement terminates by its terms or is terminated by either party in accordance
with its terms.

     This Note shall bear interest on the unpaid principal balance hereof from
time to time outstanding at a rate equal to the interest rate set forth in the
Loan Agreement.

     Accrued interest on this Note shall be payable monthly in accordance with
the terms of the Loan Agreement. Any accrued interest not paid when due shall
bear interest at the same rate as the principal hereof.

     Principal of and interest on this Note shall be payable in lawful money of
the United States of America. If a payment hereunder becomes due and payable on
a Saturday, Sunday or legal holiday, the due date thereof shall be extended to
the next succeeding business day, and interest shall be payable thereon during
such extension.

     In the event any payment of principal or interest on this Note is not paid
in full when due, or if any other default or event of default occurs hereunder,
under the Loan Agreement or under any other present or future instrument,
document, or agreement between the Borrower and Silicon (collectively, "Events
of Default"), Silicon may, at its option, at any time thereafter, declare the
entire unpaid principal balance of this Note plus all accrued interest to be
immediately due and payable, without notice or demand. The acceptance of any
installment of principal or interest by Silicon after the time when it becomes
due, as herein specified, shall not be held to establish a custom, or to waive
any rights of Silicon to enforce payment when due of any further installments or
any other rights, nor shall any failure or delay to exercise any rights be held
to waive the same.

     All payments  hereunder  are to be applied first to costs and fees referred
to  hereunder,  second to the  payment of  accrued  interest  and the  remaining
balance to the  payment of  principal.  Silicon  shall have the  continuing  and
exclusive right to apply or reverse and reapply any and all payments hereunder.

     The  Borrower  agrees  to pay all  costs and  expenses  (including  without
limitation attorney's fees) incurred by Silicon in connection with or related to
this Note, or its enforcement, whether

                                       -1-

<PAGE>

SILICON VALLEY BANK                                      SECURED PROMISSORY NOTE
--------------------------------------------------------------------------------

or not suit be brought. The Borrower hereby waives presentment, demand for
payment, notice of dishonor, notice of nonpayment, protest, notice of protest,
and any and all other notices and demands in connection with the delivery,
acceptance, performance, default, or enforcement of this Note, and the Borrower
hereby waives the benefits of any statute of limitations with respect to any
action to enforce, or otherwise related to, this Note.

     This Note is secured by the Loan Agreement and all other present and future
security agreements between the Borrower and Silicon. Nothing herein shall be
deemed to limit any of the terms or provisions of the Loan Agreement or any
other present or future document, instrument or agreement, between the Borrower
and Silicon, and all of Silicon's rights and remedies hereunder and thereunder
are cumulative.

     In the event any one or more of the provisions of this Note shall for any
reason be held to be invalid, illegal or unenforceable, the same shall not
affect any other provision of this Note and the remaining provisions of this
Note shall remain in full force and effect.

     No waiver or modification of any of the terms or provisions of this Note
shall be valid or binding unless set forth in a writing signed by a duly
authorized officer of Silicon, and then only to the extent therein specifically
set forth. If more than one person executes this Note, their obligations
hereunder shall be joint and several.

     SILICON AND BORROWER EACH HEREBY WAIVE THE RIGHT TO TRIAL BY JURY IN ANY
ACTION OR PROCEEDING BASED UPON, ARISING OUT OF, OR IN ANY WAY RELATING TO: (i)
THIS NOTE; OR (ii) ANY OTHER PRESENT OR FUTURE INSTRUMENT OR AGREEMENT BETWEEN
SILICON AND BORROWER; OR (iii) ANY CONDUCT, ACTS OR OMISSIONS OF SILICON OR
BORROWER OR ANY OF THEIR DIRECTORS, OFFICERS, EMPLOYEES, AGENTS, ATTORNEYS OR
ANY OTHER PERSONS AFFILIATED WITH SILICON OR BORROWER; IN EACH OF THE FOREGOING
CASES, WHETHER SOUNDING IN CONTRACT OR TORT OR OTHERWISE.

     This Note is payable in, and shall be governed by the laws of, the State of
California.

                                                P-COM, INC.,
                                                a Delaware corporation


                                                By /s/ Leighton J. Stephenson
                                                   --------------------------
                                                   Vice President

                                                By /s/ Caroline B. Kahl
                                                   ---------------------
                                                   Secretary


                                                P-COM NETWORK SERVICES, INC.,
                                                a Delaware corporation

                                       -2-

<PAGE>

SILICON VALLEY BANK                                      SECURED PROMISSORY NOTE
--------------------------------------------------------------------------------

                                                By   /s/ Leighton J. Stephenson
                                                   ----------------------------
                                                   Vice President

                                                By    /s/ Caroline B. Kahl
                                                   -----------------------
                                                   Secretary

                                       -3-