<PAGE>

                                                                     EXHIBIT 4.5

                                    GUARANTY

New York, New York                                              January 13, 2004

         FOR VALUE RECEIVED, and in consideration of loans made or to be made or
credit otherwise extended or to be extended by LAURUS MASTER FUND, LTD.
("Laurus") to or for the account of NUMEREX CORP. ("Company") from time to time
and at any time and for other good and valuable consideration and to induce
Laurus, in its discretion, to make such loans or extensions of credit and to
make or grant such renewals, extensions, releases of collateral or
relinquishments of legal rights as Laurus may deem advisable, the undersigned
(and each of them if more than one, the liability under this Guaranty being
joint and several) (jointly and severally referred to as "Guarantor" or "the
undersigned") unconditionally guaranties to Laurus, its successors, endorsees
and assigns the prompt payment when due (whether by acceleration or otherwise)
of all present and future obligations and liabilities of any and all kinds of
Company to Laurus arising under, out of, or in connection with that certain
Convertible Term Note dated as of the date hereof made by Company in favor of
Laurus (as amended, modified, restated or supplemented from time to time, the
"Note") and all other documents, agreements and instruments of any nature
entered into in connection therewith (the Note and all such other documents,
agreements and instruments, collectively, the "Documents") (all of which are
herein collectively referred to as the "Obligations"), and irrespective of the
genuineness, validity, regularity or enforceability of such Obligations, or of
any instrument evidencing any of the Obligations or of any security interest in
and to any collateral therefor or of the existence or extent of such collateral,
and irrespective of the allowability, allowance or disallowance of any or all of
the Obligations in any case commenced by or against Company under Title 11,
United States Code, including, without limitation, obligations or indebtedness
of Company for post-petition interest, fees, costs and charges that would have
accrued or been added to the Obligations but for the commencement of such case.
In furtherance of the foregoing, the undersigned hereby agrees as follows:

         1.       No Impairment. Laurus may at any time and from time to time,
either before or after the maturity thereof, without notice to or further
consent of the undersigned, extend the time of payment of, exchange or surrender
any collateral for, renew or extend any of the Obligations or increase or
decrease the interest rate thereon, and may also make any agreement with Company
or with any other party to or person liable on any of the Obligations, or
interested therein, for the extension, renewal, payment, compromise, discharge
or release thereof, in whole or in part, or for any modification of the terms
thereof or of any agreement between Laurus and Company or any such other party
or person, or make any election of rights Laurus may deem desirable under the
United States Bankruptcy Code, as amended, or any other federal or state
bankruptcy, reorganization, moratorium or insolvency law relating to or
affecting the enforcement of creditors' rights generally (any of the foregoing,
an "Insolvency Law") without in any way impairing or affecting this Guaranty.
This Guaranty shall be effective regardless of the subsequent incorporation,
merger or consolidation of Company, or any change in the composition, nature,
personnel or location of Company and shall extend to any successor entity to
Company, including a debtor in possession or the like under any Insolvency Law.

<PAGE>

         2.       Guaranty Absolute. The undersigned guarantees that the
Obligations will be paid strictly in accordance with the terms of the Note
and/or any other document, instrument or agreement creating or evidencing the
Obligations, regardless of any law, regulation or order now or hereafter in
effect in any jurisdiction affecting any of such terms or the rights of Company
with respect thereto. Guarantor hereby knowingly accepts the full range of risk
encompassed within a contract of "continuing guaranty" which risk includes the
possibility that Company will contract additional indebtedness for which
Guarantor may be liable hereunder after Company's financial condition or ability
to pay its lawful debts when they fall due has deteriorated, whether or not
Company has properly authorized incurring such additional indebtedness. The
undersigned acknowledges that (i) no oral representations, including any
representations to extend credit or provide other financial accommodations to
Company, have been made by Laurus to induce the undersigned to enter into this
Guaranty and (ii) any extension of credit to the Company shall be governed
solely by the provisions of the Note, the other Documents and applicable law.
The liability of the undersigned under this Guaranty shall be absolute and
unconditional, in accordance with its terms, and shall remain in full force and
effect without regard to, and shall not be released, suspended, discharged,
terminated or otherwise affected by, any circumstance or occurrence whatsoever,
including, without limitation: (a) any waiver, indulgence, renewal, extension,
amendment or modification of or addition, consent or supplement to or deletion
from or any other action or inaction under or in respect of the Documents or any
other instruments or agreements relating to the Obligations or any assignment or
transfer of any thereof, (b) any lack of validity or enforceability of any
Document or other documents, instruments or agreements relating to the
Obligations or any assignment or transfer of any thereof to an assignee of the
Note permitted pursuant to the terms of the Note and the other Documents, (c)
any furnishing of any additional security to Laurus or its assignees or any
acceptance thereof or any release of any security by Laurus or its assignees,
(d) any limitation on any party's liability or obligation under the Documents or
any other documents, instruments or agreements relating to the Obligations or
any assignment or transfer of any thereof to an assignee of the Note permitted
pursuant to the terms of the Note and the other Documents, or any invalidity or
unenforceability, in whole or in part, of any such document, instrument or
agreement or any term thereof, (e) any bankruptcy, insolvency, reorganization,
composition, adjustment, dissolution, liquidation or other like proceeding
relating to Company, or any action taken with respect to this Guaranty by any
trustee or receiver, or by any court, in any such proceeding, whether or not the
undersigned shall have notice or knowledge of any of the foregoing, (f) any
exchange, release or nonperfection of any collateral, or any release, or
amendment or waiver of or consent to departure from any guaranty or security,
for all or any of the Obligations or (g) any other circumstance which might
otherwise constitute a defense available to, or a discharge of, the undersigned.
Any amounts due from the undersigned to Laurus shall bear interest until such
amounts are paid in full at the highest rate then applicable to the Obligations
(but without duplication of any interest accrued or payable under the Note).
Obligations include post-petition interest whether or not allowed or allowable.

         3.       Waivers. (a) This Guaranty is a guaranty of payment and not of
collection. Laurus shall be under no obligation to institute suit, exercise
rights or remedies or take any other action against Company or any other person
liable with respect to any of the Obligations or resort to any collateral
security held by it to secure any of the Obligations as a condition precedent to
the undersigned being obligated to perform as agreed herein and Guarantor hereby
waives to the

                                       2
<PAGE>

fullest extent permitted by applicable law any and all rights which it may have
by statute or otherwise which would require Laurus to do any of the foregoing.
Guarantor further consents and agrees that Laurus shall be under no obligation
to marshal any assets in favor of Guarantor, or against or in payment of any or
all of the Obligations. The undersigned hereby waives all suretyship defenses
and any rights to interpose any defense, counterclaim or offset of any nature
and description which the undersigned may have by virtue of its status as a
guarantor or surety of the Obligations.

                  (b)      The undersigned further waives (i) notice of the
acceptance of this Guaranty, of the making of any such loans or extensions of
credit, and of all notices and demands of any kind to which the undersigned may
be entitled, including, without limitation, notice of adverse change in
Company's financial condition or of any other fact which might materially
increase the risk of the undersigned and (ii) presentment to or demand of
payment from anyone whomsoever liable upon any of the Obligations, protest,
notices of presentment, non-payment or protest and notice of any sale of
collateral security or any default of any sort, other than to the extent any
such notice is required under the Note, the other Documents or applicable law.

                  (c)      Notwithstanding any payment or payments made by the
undersigned hereunder, or any setoff or application of funds of the undersigned
by Laurus, the undersigned shall not be entitled to be subrogated to any of the
rights of Laurus against Company or against any collateral or guarantee or right
of offset held by Laurus for the payment of the Obligations, nor shall the
undersigned seek or be entitled to seek any contribution or reimbursement from
Company in respect of payments made by the undersigned hereunder, in each case
until all amounts owing to Laurus by Company on account of the Obligations are
paid in full and the Note has been terminated. If, notwithstanding the
foregoing, any amount shall be paid to the undersigned on account of such
subrogation rights at any time when all of the Obligations shall not have been
paid in full and the Note shall not have been terminated, such amount shall be
held by the undersigned in trust for Laurus, segregated from other funds of the
undersigned, and shall forthwith upon, and in any event within two (2) business
days of, receipt by the undersigned, be turned over to Laurus in the exact form
received by the undersigned (duly endorsed by the undersigned to Laurus, if
required), to be applied against the Obligations, whether matured or unmatured,
in such order as Laurus may determine, subject to the provisions of the Note.
Any and all present and future debts and obligations of Company to any of the
undersigned are hereby waived and postponed in favor of, and subordinated to the
full payment and performance of, all present and future debts and obligations of
Company to Laurus.

         4.       Security. All sums at any time to the credit of the
undersigned and any property of the undersigned in Laurus's possession or in the
possession of any bank, financial institution or other entity that directly or
indirectly, through one or more intermediaries, controls or is controlled by, or
is under common control with, Laurus (each such entity, an "Affiliate") shall be
deemed held by Laurus or such Affiliate, as the case may be, as security for any
and all of the undersigned's obligations to Laurus and to any Affiliate of
Laurus, no matter how or when arising and whether under this or any other
instrument, agreement or otherwise.

         5.       Representations and Warranties. The undersigned hereby
represent and warrant to Laurus (all of which representations and warranties (i)
are made as of the date of this

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Guaranty, (ii) are supplemented by and subject to the Exchange Act Filings (as
defined in the Securities Purchase Agreement, dated as of the date hereof, by
and between the Company and Laurus (as amended, modified and supplemented from
time to time, the "Securities Purchase Agreement") and the representations and
warranties made in the Securities Purchase Agreement or any schedule thereto and
(iii) shall survive until all Obligations are indefeasibly satisfied in full and
the Note has been irrevocably terminated), that:

                  (a)      Corporate Status. Each of the undersigned is duly
organized, validly existing and in good standing under the laws of its state of
formation as set forth under the undersigned's signature on the signature pages
hereto and has full corporate or other organization power, authority and legal
right to own its property and assets and to transact the business in which it is
engaged.

                  (b)      Authority and Execution. Each of the undersigned has
full corporate or other organizational power, authority and legal right to
execute and deliver, and to perform its obligations under, this Guaranty and has
taken all necessary corporate and legal action to authorize the execution,
delivery and performance of this Guaranty.

                  (c)      Legal, Valid and Binding Character. This Guaranty
constitutes the legal, valid and binding obligation of the undersigned
enforceable in accordance with its terms, except as enforceability may be
limited by applicable Insolvency Law or general principles of equity that
restrict the availability of equitable or legal remedies.

                  (d)      Violations. Except as set forth on Schedule 5(d), the
execution, delivery and performance of this Guaranty will not violate any
requirement of law applicable to the undersigned or any material contract,
agreement or instrument to which any of the undersigned is a party or by which
any of the undersigned or any property of the undersigned is bound or result in
the creation or imposition of any mortgage, lien or other encumbrance other than
to Laurus on any of the property or assets of any of the undersigned pursuant to
the provisions of any of the foregoing.

                  (e)      Consents or Approvals. Except as set forth on
Schedule 5(e), no consent of any other person or entity (including, without
limitation, any creditor of any of the undersigned) and no consent, license,
permit, approval or authorization of, exemption by, notice or report to, or
registration, filing or declaration with, any governmental authority is required
in connection with the execution, delivery, performance, validity or
enforceability of this Guaranty.

                  (f)      Litigation. Except as set forth on Schedule 4.12 to
the Securities Purchase Agreement, no litigation, arbitration, investigation or
administrative proceeding of or before any court, arbitrator or governmental
authority, bureau or agency is currently pending or, to the actual knowledge of
the officers of the undersigned, threatened (i) with respect to this Guaranty or
any of the transactions contemplated by this Guaranty or (ii) against or
affecting any of the undersigned, or any of the property or assets of any of the
undersigned, which, if adversely determined, would have a Material Adverse
Effect (as defined in the Securities Purchase Agreement).

                                        4
<PAGE>

                  (g)      Financial Benefit. The undersigned have derived or
expect to derive a financial or other advantage from each and every loan,
advance or extension of credit made under the Note.

         6.       Acceleration. It shall be an "Event of Default" under this
Guaranty if: (i) any Event of Default shall occur and be continuing under and as
defined in the Note or the Security Agreement after expiration of any notice,
cure, grace or similar period, (ii) any representation or warranty of any of the
undersigned shall have been untrue in any material respect when made, (iii) any
of the undersigned should at any time become insolvent, or make a general
assignment, or if a proceeding in or under any Insolvency Law shall be filed or
commenced by, or in respect of, any of the undersigned, which proceeding, if not
commenced by the undersigned, shall not be dismissed within 60 days of its
filing; (iv) a notice of any lien, levy, or assessment in excess of $100,000 (in
the aggregate outstanding at any time for all of the undersigned on a combined
basis) is filed of record with respect to any assets of any of the undersigned
by the United States of America or any department, agency, or instrumentality
thereof, or (v) the undersigned shall breach in the performance of any
obligation under this Guaranty in any respect. Upon the occurrence of any Event
of Default, any and all Obligations shall for purposes hereof, at Laurus'
option, be deemed due and payable without notice notwithstanding that any such
Obligation is not then due and payable by Company.

         7.       Payments from Guarantor. Laurus, in its sole and absolute
discretion, with or without notice to the undersigned, may apply on account of
the Obligations any payment from the undersigned or any other guarantor, or
amounts realized from any security for the Obligations, or may deposit any and
all such amounts realized in a non-interest bearing cash collateral deposit
account to be maintained as security for the Obligations.

         8.       Costs. The undersigned shall pay on demand, all reasonable out
of pockets costs, fees and expenses (including reasonable expenses for legal
services of every kind) relating to the enforcement or protection of the rights
of Laurus hereunder or under any of the Obligations.

         9.       No Termination. This is a continuing irrevocable guaranty and
shall remain in full force and effect and be binding upon the undersigned, and
the undersigned's successors and assigns, until all of the Obligations then
outstanding on the date on which the Note is paid in full (whether by cash
payment or by conversion of the Note to Common Stock (as defined in the
Securities Purchase Agreement) pursuant to the terms of the Note) are paid in
full, whereupon this Guaranty shall expire and terminate and be of no further
force and effect. If any of the present or future Obligations are guarantied by
persons, partnerships or corporations in addition to the undersigned, the death,
release or discharge in whole or in part or the bankruptcy, merger,
consolidation, incorporation, liquidation or dissolution of one or more of them
shall not discharge or affect the liabilities of the undersigned under this
Guaranty.

         10.      Recapture. Anything in this Guaranty to the contrary
notwithstanding, if Laurus receives any payment or payments on account of the
liabilities guaranteed hereby, which payment or payments or any part thereof are
subsequently invalidated, declared to be fraudulent or preferential, set aside
and/or required to be repaid to a trustee, receiver, or any other party under
any Insolvency Law, common law or equitable doctrine, then to the extent of any
sum not finally retained by Laurus, the undersigned's obligations to Laurus
shall be reinstated and this

                                        5
<PAGE>

Guaranty shall remain in full force and effect (or be reinstated) until payment
shall have been made to Laurus, which payment shall be due on demand.

         11.      No Waiver. No failure on the part of Laurus to exercise, and
no delay in exercising, any right, remedy or power hereunder shall operate as a
waiver thereof, nor shall any single or partial exercise by Laurus of any right,
remedy or power hereunder preclude any other or future exercise of any other
legal right, remedy or power. Each and every right, remedy and power hereby
granted to Laurus or allowed it by law or other agreement shall be cumulative
and not exclusive of any other, and may be exercised by Laurus at any time and
from time to time.

         12.      Waiver of Jury Trial. THE GUARANTOR AND THE INDIVIDUALS
EXECUTING THIS INSTRUMENT ON BEHALF OF THE GUARANTOR DOES HEREBY KNOWINGLY,
VOLUNTARILY AND INTENTIONALLY WAIVE THE RIGHT TO TRIAL BY JURY IN ANY ACTION OR
PROCEEDING BASED ON OR WITH RESPECT TO THIS GUARANTY OR ANY OF THE TRANSACTIONS
CONTEMPLATED HEREBY OR RELATING OR INCIDENTAL HERETO. THE UNDERSIGNED DOES
HEREBY CERTIFY THAT NO REPRESENTATIVE OR AGENT OF LAURUS HAS REPRESENTED,
EXPRESSLY OR OTHERWISE, THAT LAURUS WOULD NOT, IN THE EVENT OF LITIGATION, SEEK
TO ENFORCE THIS WAIVER OF RIGHT TO JURY TRIAL PROVISION.

         13.      Governing Law; Jurisdiction; Amendments. THIS INSTRUMENT SHALL
BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW
YORK, WITHOUT REGARD TO PRINCIPLES OF CONFLICTS OF LAWS. ANY ACTION BROUGHT BY
EITHER PARTY AGAINST THE OTHER CONCERNING THE TRANSACTIONS CONTEMPLATED BY THIS
INSTRUMENT SHALL BE BROUGHT ONLY IN ANY STATE OR FEDERAL COURT SITTING IN THE
BOROUGH OF MANHATTAN, CITY OF NEW YORK; PROVIDED THAT NOTHING CONTAINED IN THIS
INSTRUMENT SHALL BE DEEMED TO PRECLUDE LAURUS FROM BRINGING SUIT OR TAKING OTHER
LEGAL ACTION IN ANY OTHER COURT OF COMPETENT JURISDICTION AND NOTHING SHALL BE
DEEMED TO PRECLUDE THE GUARANTOR FROM ASSERTING ANY DEFENSES OR COUNTERCLAIMS IN
ANY SUCH ACTIONS. THE GUARANTOR AND THE INDIVIDUALS EXECUTING THIS INSTRUMENT ON
BEHALF OF THE GUARANTOR AGREE TO SUBMIT TO THE JURISDICTION OF SUCH COURTS. THE
GUARANTOR AND THE INDIVIDUALS EXECUTING THIS INSTRUMENT FURTHER CONSENT THAT ANY
SUMMONS, SUBPOENA OR OTHER PROCESS OR PAPERS (INCLUDING, WITHOUT LIMITATION, ANY
NOTICE OR MOTION OR OTHER APPLICATION TO EITHER OF THE AFOREMENTIONED COURTS OR
A JUDGE THEREOF) OR ANY NOTICE IN CONNECTION WITH ANY PROCEEDINGS HEREUNDER, MAY
BE SERVED BY REGISTERED OR CERTIFIED MAIL, RETURN RECEIPT REQUESTED, OR BY
PERSONAL SERVICE PROVIDED A REASONABLE TIME FOR APPEARANCE IS PERMITTED, OR IN
SUCH OTHER MANNER AS MAY BE PERMISSIBLE UNDER THE RULES OF SAID COURTS. THE
GUARANTOR AND THE INDIVIDUALS EXECUTING THIS INSTRUMENT WAIVE ANY OBJECTION TO
JURISDICTION AND VENUE OF ANY ACTION INSTITUTED HEREON IN THE SUPREME COURT FOR
THE STATE OF

                                        6
<PAGE>

NEW YORK, COUNTY OF NEW YORK, OR THE UNITED STATES DISTRICT COURT FOR THE
SOUTHERN DISTRICT OF NEW YORK AND SHALL NOT ASSERT ANY DEFENSE BASED ON LACK OF
JURISDICTION OR VENUE OR BASED UPON FORUM NON CONVENIENS FOR ANY ACTION FILED IN
EITHER SUCH COURT. THE PREVAILING PARTY SHALL BE ENTITLED TO RECOVER FROM THE
OTHER PARTY ITS REASONABLE ATTORNEY'S FEES AND COSTS; PROVIDED, HOWEVER, THAT IF
THE PARTIES HERETO AGREE TO SETTLE ANY CLAIM, ACTION, PROCEEDING OR LAWSUIT
BROUGHT BY ONE PARTY HERETO AGAINST THE OTHER PARTY HERETO, THEN EACH OF THE
PARTIES SHALL BEAR ITS OWN COSTS IN CONNECTION WITH SUCH CLAIM, ACTION,
PROCEEDING OR LAWSUIT, UNLESS OTHERWISE DIRECTED BY A COURT OF COMPETENT
JURISDICTION.

         14.      Severability. In the event that any provision of this Guaranty
is invalid or unenforceable under any applicable statute or rule of law, then
such provision shall be deemed inoperative to the extent that it may conflict
therewith and shall be deemed modified to conform with such statute or rule of
law. Any such provision which may prove invalid or unenforceable under any law
shall not affect the validity or unenforceability of any other provision of this
Guaranty.

         15.      Amendments, Waivers. No amendment or waiver of any provision
of this Guaranty nor consent to any departure by the undersigned therefrom shall
in any event be effective unless the same shall be in writing executed by the
undersigned and Laurus.

         16.      Notice. All notices, requests and demands to or upon the
undersigned, shall be in writing and shall be deemed to have been duly given or
made (a) when delivered, if by hand, (b) three (3) days after being sent,
postage prepaid, if by registered or certified mail, (c) when confirmed
electronically, if by facsimile, or (d) when delivered, if by a recognized
overnight delivery service in each event, to the numbers and/or address set
forth beneath the signature of the undersigned, with a copy to: Legal Counsel,
Numerex Corp., 1600 Parkwood Circle SE, Suite 200, Atlanta, Georgia 30339,
facsimile: (770) 693-5951, and Richard Baltz, Esq., Arnold & Porter, 555 12th
Street, N.W., Washington, D.C. 20004, facsimile: (202) 942-5999.

         17.      Successors. Laurus may, from time to time, without notice to
the undersigned, sell, assign, transfer or otherwise dispose of all or any part
of the Obligations and/or rights under this Guaranty to any assignee or
transferee of the Note, but only to the extent such assignment is permitted by
the Note or Securities Purchase Agreement. Without limiting the generality of
the foregoing, Laurus may assign, or grant participations to, one or more banks,
financial institutions or other entities all or any part of any of the
Obligations who are assignees, transferees or participants in a corresponding
portion of the Note. In each such event, Laurus and each and every immediate and
successive purchaser, assignee, transferee or holder of all or any part of the
Obligations shall, acting as a single, unified group, have the right to enforce
this Guaranty, by legal action or otherwise, for their own benefit as fully as
if such purchasers, assignees, transferees or holders were herein by name
specifically given such right; provided, however, that the holders of the
Obligations shall appoint an agent to act on their behalf and shall act and
enforce rights and remedies through a single action.

                                        7
<PAGE>

         18.      Release. Nothing except payment in full of all Obligations
then outstanding on the date all amounts due under the Note are paid in full
(whether by cash payment or by conversion of the Note to Common Stock (as
defined in the Securities Purchase Agreement) pursuant to the terms of the Note)
shall release the undersigned from liability under this Guaranty.

                                        8
<PAGE>

         IN WITNESS WHEREOF, this Guaranty has been executed by the undersigned
this 13th day of January, 2004.

                                     NUMEREX SOLUTIONS, LLC

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   MANAGER
                                         --------------------------------
                                     Address: 1600 Parkwood Circle SE, Suite 200
                                              Atlanta, GA 30339
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Delaware

                                     CELLEMETRY LLC

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   MANAGER
                                         --------------------------------
                                     Address: 1600 Parkwood Circle SE, Suite 200
                                              Atlanta, GA 30339
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Delaware

                                     NUMEREX INVESTMENT CORP.

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   CEO
                                         --------------------------------

                                     Address: 1600 Parkwood Circle SE, Suite 200
                                              Atlanta, GA 30339
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Delaware

<PAGE>

                                     BROADBAND NETWORKS INC.

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   CEO
                                         --------------------------------

                                     Address: 2820 E. College Ave. Suite B
                                              State College, PA 16801-7548
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Delaware


                                     BNI SOLUTIONS LLC

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   MANAGER
                                         --------------------------------

                                     Address: 2820 E. College Ave. Suite B
                                              State College, PA 16801-7548
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Delaware

                                     DIGILOG INC.

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   CEO
                                         --------------------------------

                                     Address: 2360 Maryland Road
                                              Willow Grove, PA 19090
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Pennsylvania

                                       10
<PAGE>

                                     DCX SYSTEMS INC.

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   CEO
                                         --------------------------------

                                     Address: 2360 Maryland Road
                                              Willow Grove, PA 19090
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Pennsylvania

                                     DCX SYSTEMS AUSTRALIA PTY LIMITED

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   DIRECTOR
                                         --------------------------------

                                     Address: Lindfield Executive Centre
                                              12 Tryon Rd.
                                              P.O. Box 42
                                              Lindfield, NSW 2072, Australia
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Australia

                                     MOBILEGUARDIAN LLC

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   MANAGER
                                         --------------------------------

                                     Address: 1600 Parkwood Circle SE, Suite 200
                                              Atlanta, GA 30339
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Delaware

                                     UPLINK SECURITY, INC.

                                     By: /s/ STRATTON J. NICOLAIDES
                                        ---------------------------------
                                     Its:   CEO
                                         --------------------------------

                                     Address: 1600 Parkwood Circle SE, Suite 200
                                              Atlanta, GA 30339
                                     Telephone No.: (770) 485-2527
                                     Facsimile No.: (770) 693-5951

                                     State of Formation: Georgia

                                       11
<PAGE>

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the Manager of Cellemetry, LLC, the limited liability company described in
and which executed the above instrument; and that s/he signed her/his name
thereto by order of the board of directors of said limited liability company.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the Manager of Numerex Solutions LLC, the limited liability company described
in and which executed the above instrument; and that s/he signed her/his name
thereto by order of the board of directors of said limited liability company.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

<PAGE>

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the CEO of Numerex Investment Corp., the corporation described in and which
executed the above instrument; and that s/he signed her/his name thereto by
order of the board of directors of said corporation.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the CEO of BroadBand Networks Inc., the corporation described in and which
executed the above instrument; and that s/he signed her/his name thereto by
order of the board of directors of said corporation.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the Manager of BNI Solutions LLC, the limited liability company described in
and which executed the above instrument; and that s/he signed her/his name
thereto by order of the board of directors of said limited liability company.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

                                       13
<PAGE>

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the CEO of Digilog Inc., the corporation described in and which executed the
above instrument; and that s/he signed her/his name thereto by order of the
board of directors of said corporation.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the CEO of DCX Systems Inc., the corporation described in and which executed
the above instrument; and that s/he signed her/his name thereto by order of the
board of directors of said corporation.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the Director of DCX Systems Australia PTY Limited, the ______________
described in and which executed the above instrument; and that s/he signed
her/his name thereto by order of the board of directors of said
__________________.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the Manager of MobileGuardian LLC, the limited liability company described in
and which executed the above instrument; and that s/he signed her/his name
thereto by order of the board of directors of said limited liability company.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

                                       14
<PAGE>

STATE OF Georgia )
     : ss.:
COUNTY OF Cobb )

         On the 13th day of January, 2004, before me personally came Stratton J.
Nicolaides to me known, who, being by me duly sworn did depose and say that s/he
is the CEO of Uplink Security, Inc., the corporation described in and which
executed the above instrument; and that s/he signed her/his name thereto by
order of the board of directors of said corporation.

                                     /s/ Pamela S. Lester
                                     -------------------------------
                                     Notary Public

                                       15