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                                                                    Exhibit 10.5

                             APPLIED INNOVATION INC.

                              EMPLOYMENT AGREEMENT

         This Agreement is made as of this 15th day of August, 2001, by and
between KARL FOX and APPLIED INNOVATION INC., a Delaware corporation with its
principal office at 5800 Innovation Drive, Dublin, Ohio 43016, its subsidiaries,
successors and assigns (the "Company").

                                    RECITALS

         A. The Company is engaged in the business of developing, manufacturing,
and marketing data communications and data transmission equipment, software, and
services to telephone companies, interexchange telephone carriers, cable
television companies, and electric utilities, for alarm data communications,
network mediation and management, interoperability of networks, and network
switching and routing, and develops and uses valuable technical and nontechnical
trade secrets and other confidential information which it desires to protect.

         B. You are currently employed as an executive officer of the Company.

         C. The Company considers your continued services to be in the best
interest of the Company and desires, through this Agreement, to assure your
continued services on behalf of the Company on an objective and impartial basis
and without distraction or conflict of interest in the event of an attempt to
obtain control of the Company.

         D. You are willing to become employed by and to remain in the employ of
the Company on the terms set forth in this agreement.

                                    AGREEMENT

         NOW, THEREFORE, the parties agree as follows:

         1. CONSIDERATION. As consideration for your entering into this
Agreement and your willingness to remain bound by its terms, the Company shall
employ you and provide you with access to certain Confidential Information as
defined in this Agreement and other valuable consideration as provided for
throughout this Agreement, including in Sections 3 and 4 of this Agreement.

         2. EMPLOYMENT.

                  (a) POSITION. You will be employed as Vice President of
Engineering, reporting to the President and Chief Executive Officer of the
Company. You shall perform the duties, undertake the responsibilities and
exercise the authority customarily performed, undertaken and exercised by
persons employed in similar executive capacities.

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         (b) RESTRICTED EMPLOYMENT. While employed by the Company, you shall
devote your best efforts to the business of the Company and shall not engage in
any outside employment or consulting work without first securing the approval of
the Company's Board of Directors. Furthermore, so long as you are employed under
this Agreement, you agree to devote your full time and efforts exclusively on
behalf of the Company and to competently, diligently, and effectively discharge
your duties hereunder. You shall not be prohibited from engaging in such
personal, charitable, or other nonemployment activities that do not interfere
with your full time employment hereunder and which do not violate the other
provisions of this Agreement. You further agree to comply fully with all
policies and practices of the Company as are from time to time in effect.

         3. COMPENSATION.

                  (a) Your compensation will be at an annual base rate of
$145,000 through December 31, 2001 ("Basic Salary"), payable in accordance with
the normal payroll practices of the Company. Your base salary may be increased
from time to time by action of the Board of Directors of the Company. You will
also be eligible for a cash bonus under a bonus plan which is determined
annually by the Board of Directors of the Company.

                  (b) You will be entitled to receive stock options to purchase
shares of the common stock of the Company pursuant to the terms of plans adopted
by the Board of Directors of the Company from time to time. If a "Change in
Control," as defined in Section 9(e)(v), shall occur (i) in which the Company
does not survive as a result of such Change in Control or substantially all of
the assets of the Company are sold as a result of such Change in Control, and
(ii) in which the surviving entity does not assume the obligations of your
outstanding stock options upon the Change in Control, then vesting of all
outstanding stock options issued to you prior to the Change in Control will be
accelerated by twenty-four (24) months plus an additional twelve (12) months for
each full year you have been employed by the Company and such options will be
exercisable (to the extent then vested) for a period of thirty (30) days from
the date of the Change in Control.

                  (c) Subject to applicable Company policies, you will be
reimbursed for necessary and reasonable business expenses incurred in connection
with the performance of your duties hereunder or for promoting, pursuing or
otherwise furthering the business or interests of the Company.

         4. FRINGE BENEFITS. You will be entitled to receive employee benefits
and participate in any employee benefit plans, in accordance with their terms as
from time to time amended, that the Company maintains during your employment and
which are made generally available to all other management employees in like
positions. This includes a 401(k) and profit sharing plan and paid medical
insurance. It is agreed that the Company will pay any necessary COBRA payments
on your behalf due to any break in medical coverage for any reason, including
pre-existing conditions.

         5. RESERVED.

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         6. CONFIDENTIAL INFORMATION.

                  (a) As used throughout this Agreement, the term "Confidential
Information" means any information you acquire during employment by the Company
(including information you conceive, discover or develop) which is not readily
available to the general public and which relates to the business, including
research and development projects, of the Company, its subsidiaries or its
affiliated companies.

                  (b) Confidential Information INCLUDES, without limitation,
information of a technical nature (such as trade secrets, inventions,
discoveries, product requirements, designs, software codes and manufacturing
methods), matters of a business nature (such as customer lists, the identities
of customer contacts, information about customer requirements and preferences,
the terms of the Company's contracts with its customers and suppliers, and the
Company's costs and prices), personnel information (such as the identities,
duties, customer contacts, and skills of the Company's employees) and other
financial information relating to the Company and its customers (including
credit terms, methods of conducting business, computer systems, computer
software, personnel data, and strategic marketing, sales or other business
plans). Confidential Information may or may not be patentable.

                  (c) Confidential Information DOES NOT INCLUDE information
which you learned prior to employment with the Company from sources other than
the Company, information you develop after employment from sources other than
the Company's Confidential Information or information which is readily available
to persons with equivalent skills, training and experience in the same fields or
fields of endeavor as you. You must presume that all information that is
disclosed or made accessible to you during employment by the Company is
Confidential Information if you have a reasonable basis to believe the
information is Confidential Information or if you have notice that the Company
treats the information as Confidential Information.

                  (d) Except in conducting the Company's business, you shall not
at any time, either during or following your employment with the Company, make
use of, or disclose to any other person or entity, any Confidential Information
unless (i) the specific information becomes public from a source other than you
or another person or entity that owes a duty of confidentiality to the Company
AND (ii) twelve months have passed since the specific information became public.
However, you may discuss Confidential Information with employees of the Company
when necessary to perform your duties to the Company. Notwithstanding the
foregoing, if you are ordered by a court of competent jurisdiction to disclose
Confidential Information, you will officially advise the Court that you are
under a duty of confidentiality to the Company hereunder, take reasonable steps
to delay disclosure until the Company may be heard by the Court, give the
Company prompt notice of such Court order, and if ordered to disclose such
Confidential Information you shall seek to do so under seal or in camera or in
such other manner as reasonably designed to restrict the public disclosure and
maintain the maximum confidentiality of such Confidential Information.

                  (e) Upon Employment Separation, you shall deliver to the
Company all originals, copies, notes, documents, computer data bases, disks, and
CDs, or records of any kind that reflect or relate to any Confidential
Information. As used herein, the term "notes" means

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written or printed words, symbols, pictures, numbers or formulae. As used
throughout this Agreement, the term "Employment Separation" means the separation
from and/or termination of your employment with the Company, regardless of the
time, manner or cause of such separation or termination.

         7. INVENTIONS.

                  (a) As used throughout this Agreement, the term "Inventions"
means any inventions, improvements, designs, plans, discoveries or innovations
of a technical or business nature, whether patentable or not, relating in any
way to the Company's business or contemplated business if the Invention is
conceived or reduced to practice by you during your employment by the Company.
Inventions includes all data, records, physical embodiments and intellectual
property pertaining thereto. Inventions reduced to practice within one year
following Employment Separation shall be presumed to have been conceived during
employment.

                  (b) Inventions are the Company's exclusive property and shall
be promptly disclosed and assigned to the Company without additional
compensation of any kind. If requested by the Company, you, your heirs, your
executors, your administrators or legal representative will provide any
information, documents, testimony or other assistance needed for the Company to
acquire, maintain, perfect or exercise any form of legal protection that the
Company desires in connection with an Invention.

                  (c) Upon Employment Separation, you shall deliver to the
Company all copies of and all notes with respect to all documents or records of
any kind that relate to any Inventions.

         8. NONCOMPETITION AND NONSOLICITATION.

                  (a) By entering into this Agreement, you acknowledge that the
Confidential Information has been and will be developed and acquired by the
Company by means of substantial expense and effort, that the Confidential
Information is a valuable asset of the Company's business, that the disclosure
of the Confidential Information to any of the Company's competitors would cause
substantial and irreparable injury to the Company's business, and that any
customers of the Company developed by you or others during your employment are
developed on behalf of the Company. You further acknowledge that you have been
provided with access to Confidential Information, including Confidential
Information concerning the Company's major customers, and its technical,
marketing and business plans, disclosure or misuse of which would irreparably
injure the Company.

                  (b) In exchange for the consideration specified in Section 1
of this Agreement -- the adequacy of which you expressly acknowledge -- you
agree that during your employment by the Company and for a period of twelve (12)
months following Employment Separation, you shall not, directly or indirectly,
as an owner, shareholder, officer, employee, manager, consultant, independent
contractor, or otherwise:

                           (i) Attempt to recruit or hire, interfere with or
         harm, or attempt to interfere with or harm, the relationship of the
         Company, its subsidiaries or affiliates, with

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         any person who is an employee, customer or supplier of the Company, it
         subsidiaries or affiliates;

                           (ii) Contact any employee of the Company for the
         purpose of discussing or suggesting that such employee resign from
         employment with the Company for the purpose of becoming employed
         elsewhere or provide information about individual employees of the
         Company or personnel policies or procedures of the Company to any
         person or entity, including any individual, agency or company engaged
         in the business of recruiting employees, executives or officers; or

                           (iii) Own, manage, operate, join, control, be
         employed by, consult with or participate in the ownership, management,
         operation or control of, or be connected with (as a stockholder,
         partner, or otherwise), any business, individual, partner, firm,
         corporation, or other entity that competes or plans to compete,
         directly or indirectly, with the Company, its products, or any
         division, subsidiary or affiliate of the Company; provided, however,
         that your "beneficial ownership," either individually or as a member of
         a "group" as such terms are used in Rule 13d of the General Rules and
         Regulations under the Securities Exchange Act of 1934, as amended (the
         "Exchange Act"), of not more than two percent (2%) of the voting stock
         of any publicly held corporation, shall not be a violation of this
         Agreement.

         9. TERMINATION OF EMPLOYMENT.

                  (a) Termination Upon Death or Disability. Your employment will
terminate automatically upon your death. The Company will be entitled to
terminate your employment because of your disability upon 30 days written
notice. "Disability" will mean "total disability" as defined in the Company's
long term disability plan or any successor thereto. In the event of a
termination under this Section 9(a), the Company will pay you only the earned
but unpaid portion of your Basic Salary through the termination date.

                  (b) Termination by Company for Cause. An Employment Separation
for Cause will occur upon a determination by the Company that "Cause" exists for
your termination and the Company serves you written notice of such termination.
As used in this Agreement, the term "Cause" shall refer only to any one or more
of the following grounds:

                           (i) Commission of an act of dishonesty involving the
         Company, its business or property, including, but not limited to,
         misappropriation of funds or any property of the Company;

                           (ii) Engagement in activities or conduct clearly
         injurious to the best interests or reputation of the Company;

                           (iii) Willful and continued failure substantially to
         perform your duties under this Agreement (other than as a result of
         physical or mental illness or injury), after the Board of Directors of
         the Company delivers to you a written demand for substantial
         performance that specifically identifies the manner in which the Board
         believes that you have not substantially performed your duties;

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                           (iv) Illegal conduct or gross misconduct that is
         willful and results in material and demonstrable damage to the
         business or reputation of the Company;

                           (v) The clear violation of any of the material terms
         and conditions of this Agreement or any other written agreement or
         agreements you may from time to time have with the Company;

                           (vi) The clear violation of the Company's code of
         business conduct or the clear violation of any other rules of behavior
         as may be provided in any employee handbook which would be grounds for
         dismissal of any employee of the Company; or

                           (vii) Commission of a crime which is a felony, a
         misdemeanor involving an act of moral turpitude, or a misdemeanor
         committed in connection with your employment by the Company which
         causes the Company a substantial detriment.

                  No act or failure to act shall be considered "willful" unless
  it is done, or omitted to be done, by you in bad faith or without reasonable
  belief that your action or omission was in the best interests of the Company.
  Any act or failure to act that is based upon authority given pursuant to a
  resolution duly adopted by the Board of Directors, or the advice of counsel
  for the Company, shall be conclusively presumed to be done, or omitted to be
  done, by you in good faith and in the best interests of the Company.

                  In the event of a termination under this Section 9(b), the
Company will pay you only the earned but unpaid portion of your Basic Salary
through the termination date.

                  Following a termination for Cause by the Company, if you
desire to contest such determination, your sole remedy will be to submit the
Company's determination of Cause to arbitration in Columbus, Ohio before a
single arbitrator under the commercial arbitration rules of the American
Arbitration Association. If the arbitrator determines that the termination was
other than for Cause, the Company's sole liability to you will be the amount
that would be payable to you under Section 9(d) of this Agreement for a
termination of your employment by the Company without Cause. Each party will
bear his or its own expenses of the arbitration.

                  (c) Termination by You. In the event of an Employment
Separation as a result of a termination by you for any reason, you must provide
the Company with at least 14 days advance written notice ("Notice of
Termination") and continue working for the Company during the 14-day notice
period, but only if the Company so desires to continue your employment and to
compensate you during such period.

                  In the event of such termination under this Section, the
Company will pay you the earned but unpaid portion of your Basic Salary through
the termination date.

                  (d) Termination by Company Without Cause. In the event of an
Employment Separation as a result of termination by the Company without Cause,
the Company will pay you the earned but unpaid portion of your Basic Salary
through the termination date and will continue to

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pay you your Basic Salary for an additional six (6) months (the "Severance
Period"); provided, however, any such payments will immediately end if (i) you
are in violation of any of your obligations under this Agreement, including
Sections 6, 7 and/or 8; or (ii) the Company, after your termination, learns of
any facts about your job performance or conduct that would have given the
Company Cause, as defined in Section 9(b), to terminate your employment.

                  (e) Termination Following Change of Control. If a "Change in
Control", as defined in Section 9(e)(v), shall have occurred and within 13
months following such Change in Control the Company terminates your employment
other than for Cause, as defined in Section 9(b), or you terminate your
employment for Good Reason, as that term is defined in Section 9(e)(vii), then
you shall be entitled to the benefits described below:

                           (i) You shall be entitled to the unpaid portion of
                  your Basic Salary plus credit for any vacation accrued but not
                  taken and the amount of any earned but unpaid portion of any
                  bonus, incentive compensation, or any other Fringe Benefit to
                  which you are entitled under this Agreement through the date
                  of the termination as a result of a Change in Control (the
                  "Unpaid Earned Compensation"), plus 1.0 times your "Current
                  Annual Compensation" as defined in this Section 9(e)(i) (the
                  "Salary Termination Benefit"). "Current Annual Compensation"
                  shall mean the total of your Basic Salary in effect at the
                  Termination Date, plus the average annual performance bonus
                  actually received by you over the last three years fiscal
                  years (or if you have been employed for a shorter period of
                  time over such period during which you performed services for
                  the Company), and shall not include the value of any stock
                  options granted or exercised, restricted stock awards granted
                  or vested, contributions to 401(k) or other qualified plans,
                  medical, dental, or other insurance benefits, or other fringe
                  benefits.

                           (ii) Vesting of all outstanding stock options and
                  restricted stock awards issued to you will be accelerated by
                  twenty-four (24) months plus an additional twelve (12) months
                  for each full year you have been employed by the Company, and
                  thereafter shall be exercisable in accordance with such
                  governing stock option or restricted stock agreements and
                  plans.

                           (iii) The Company shall maintain for your benefit (or
                  at your election make COBRA payments for your benefit), until
                  the earlier of (A) 12 months after termination of employment
                  following a Change in Control, or (B) your commencement of
                  full-time employment with a new employer, all life insurance,
                  medical, health and accident, and disability plans or
                  programs, such plans or programs to be maintained at the then
                  current standards of the Company, in which you shall have been
                  entitled to participate prior to termination of employment
                  following a Change in Control, provided your continued
                  participation is permitted under the general terms of such
                  plans and programs after the Change in Control ("Fringe
                  Termination Benefit"); (collectively the Salary Termination
                  Benefit and the Fringe Termination Benefit are referred to as
                  the "Termination Benefits").

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                           (iv) The Unpaid Earned Compensation shall be paid to
                  you within 15 days after termination of employment, one-half
                  of the Termination Benefits shall be payable to you as
                  severance pay in a lump sum payment within 30 days after
                  termination of employment, and one-half of the Termination
                  Benefits shall be payable to you as severance pay in 12
                  monthly payments commencing 30 days after termination of
                  employment; provided, however, the Company may immediately
                  discontinue the payment of the Termination Benefits if (i) you
                  are in violation of any of your obligations under this
                  Agreement, including in Sections 6, 7 and/or 8; and/or (ii)
                  the Company, after your termination, learns of any facts about
                  your job performance or conduct that would have given the
                  Company Cause as defined in Section 9(b) to terminate your
                  employment. You shall have no duty to mitigate your damages by
                  seeking other employment, and the Company shall not be
                  entitled to set off against amounts payable hereunder any
                  compensation which you may receive from future employment.

                           (v) A "Change in Control" shall be deemed to have
                  occurred if and when, after the date hereof, (i) any "person"
                  (as that term is used in Section 13(d) and 14(d) of the
                  Securities Exchange Act of 1934, as amended (the "Exchange
                  Act") on the date hereof), including any "group" as such term
                  is used in Section 13(d)(3) of the Exchange Act on the date
                  hereof, shall acquire (or disclose the previous acquisition
                  of) beneficial ownership (as that term is defined in Section
                  13(d) of the Exchange Act and the rules thereunder on the date
                  hereof) of shares of the outstanding stock of any class or
                  classes of the Company which results in such person or group
                  possessing more than 50% of the total voting power of the
                  Company's outstanding voting securities ordinarily having the
                  right to vote for the election of directors of the Company; or
                  (ii) as the result of, or in connection with, any tender or
                  exchange offer, merger or other business combination, or
                  contested election, or any combination of the foregoing
                  transactions (a "Transaction"), the owners of the voting
                  shares of the Company outstanding immediately prior to such
                  Transaction own less than a majority of the voting shares of
                  the Company after the Transaction; or (iii) during any period
                  of two consecutive years during the term of this Agreement,
                  individuals who at the beginning of such period constitute the
                  Board of Directors of the Company (or who take office
                  following the approval of a majority of the directors then in
                  office who were directors at the beginning of the period)
                  cease for any reason to constitute at least one-half thereof,
                  unless the election of each director who was not a director at
                  the beginning of such period has been approved in advance by
                  directors of the Company representing at least one-half of the
                  directors then in office who were directors at the beginning
                  of the period; or (iv) the sale, exchange, transfer, or other
                  disposition of all or substantially all of the assets of the
                  Company (a "Sale Transaction") shall have occurred.

                            (vi) If any portion of the payments and benefits
                  provided under this Agreement to you, alone or with other
                  payments and benefits, would constitute "parachute payments"
                  within the meaning of Section 280G(b)(2) of the Internal
                  Revenue Code of 1986, as amended (the "Code"), and shall be
                  determined by the Company's independent compensation
                  specialist to be nondeductible to the

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                  Company, then the aggregate present value of all of the
                  amounts payable to you under Section 9(e) hereof shall be
                  reduced to the maximum amount which would cause all of the
                  payments under Section 9(e) to be deductible and in such event
                  you shall have the option, but not the obligation, to
                  designate or select those kinds of payments which shall be
                  reduced and the order of such reductions, but your failure to
                  make such selections within a period of 30 days following
                  notice of the determination that a reduction is necessary will
                  result in a reduction of all such payments, pro rata. If you
                  disagree with the determination of the reduced amount by the
                  Company's independent compensation specialist, you may contest
                  that determination by giving notice of such contest within 30
                  days of learning of the determination and may use an
                  independent compensation specialist of your choice in
                  connection with such contest. The Company shall pay all of
                  your costs in connection with such contest if the ultimate
                  determination by the two independent compensation specialists
                  in consultation with each other, or by a third independent
                  compensation specialist, jointly chosen by the two first-named
                  independent compensation specialists in the event the first
                  two cannot agree, represents a lesser reduction in the amounts
                  payable under Section 9(e) hereof than the Company's
                  independent compensation specialist established in the first
                  instance. Otherwise, you shall pay your own and any additional
                  costs incurred by the Company in contesting such
                  determination. If there is a final determination by the
                  Internal Revenue Service or a court of competent jurisdiction
                  that the Company overpaid amounts under Section 280G of the
                  Code, the amount of the overpayment shall be treated as a loan
                  to you and shall be repaid immediately, together with interest
                  on such amount at the prime rate of interest at Huntington
                  National Bank, Columbus, Ohio, or any successor thereto, in
                  effect from time to time. If the Internal Revenue Service or a
                  court of competent jurisdiction finally determines, or if the
                  Code or regulations thereunder shall change such that the
                  Company underpaid you under Section 280G of the Code, the
                  Company shall pay the difference to you with interest as
                  specified above.

                           (vii) As used in this Agreement, the term "Good
                  Reason" means, without your written consent:

                                    (A) a material change in your status,
                           position or responsibilities which, in your
                           reasonable judgment, does not represent a promotion
                           from your existing status, position or
                           responsibilities as in effect immediately prior to
                           the Change in Control; the assignment of any duties
                           or responsibilities or the removal or termination of
                           duties or responsibilities (except in connection with
                           the termination of employment for total and permanent
                           disability, death, or Cause, or by you other than for
                           Good Reason), which, in your reasonable judgment, are
                           materially inconsistent with such status, position or
                           responsibilities;

                                    (B) a reduction by the Company in your Basic
                           Salary as in effect on the date hereof or as the same
                           may be increased from time to time during the term of
                           this Agreement or the Company's failure to increase
                           (within twelve months of your last increase in Basic
                           Salary) your Basic Salary after a

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                           Change in Control in an amount which at least equals,
                           on a percentage basis, the average percentage
                           increase in Basic Salary for all executive and senior
                           officers of the Company, in like positions, which
                           were effected in the preceding twelve months;

                                    (C) the relocation of the Company's
                           principal executive offices to a location outside the
                           Columbus metropolitan area or the relocation of you
                           by the Company to any place other than the location
                           at which you performed duties prior to a Change in
                           Control, except for required travel on the Company's
                           business to an extent consistent with business travel
                           obligations at the time of a Change in Control;

                                    (D) the failure of the Company to continue
                           in effect, or continue or materially reduce your
                           participation in, any incentive, bonus or other
                           compensation plan in which you participate, including
                           but not limited to the Company's stock option plans,
                           unless an equitable arrangement (embodied in an
                           ongoing substitute or alternative plan), has been
                           made or offered with respect to such plan in
                           connection with the Change in Control;

                                    (E) the failure by the Company to continue
                           to provide you with benefits substantially similar to
                           those enjoyed or to which you are entitled under any
                           of the Company's pension, profit sharing, life
                           insurance, medical, dental, health and accident, or
                           disability plans at the time of a Change in Control,
                           the taking of any action by the Company which would
                           directly or indirectly materially reduce any of such
                           benefits or deprive you of any material fringe
                           benefit enjoyed or to which you are entitled at the
                           time of the Change in Control, or the failure by the
                           Company to provide the number of paid vacation and
                           sick leave days to which you are entitled on the
                           basis of years of service with the Company in
                           accordance with the Company's normal vacation policy
                           in effect on the date hereof;

                                    (F) the failure of the Company to obtain a
                           satisfactory agreement from any successor or assign
                           of the Company to assume and agree to perform this
                           Agreement;

                                    (G) any request by the Company that you
                           participate in an unlawful act or take any action
                           constituting a breach of your professional standard
                           of conduct; or

                                    (H) any breach of this Agreement on the part
                           of the Company.

                           Notwithstanding anything in this Section to the
                           contrary, your right to terminate your employment
                           pursuant to this Section shall not be affected by
                           incapacity due to physical or mental illness.

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                           (viii) Upon any termination or expiration of this
                  Agreement or any cessation of your employment hereunder, the
                  Company shall have no further obligations under this Agreement
                  and no further payments shall be payable by the Company to
                  you, except as provided in Section 9 above and except as
                  required under any benefit plans or arrangements maintained by
                  the Company and applicable to you at the time of such
                  termination, expiration or cessation of your employment.

                           (ix) Enforcement of Agreement. The Company is aware
                  that upon the occurrence of a Change in Control, the Board of
                  Directors or a shareholder of the Company may then cause or
                  attempt to cause the Company to refuse to comply with its
                  obligations under this Agreement, or may cause or attempt to
                  cause the Company to institute, or may institute litigation
                  seeking to have this Agreement declared unenforceable, or may
                  take or attempt to take other action to deny you the benefits
                  intended under this Agreement. In these circumstances, the
                  purpose of this Agreement could be frustrated. Accordingly, if
                  following a Change in Control it should appear to you that the
                  Company has failed to comply with any of its obligations under
                  Section 9 of this Agreement or in the event that the Company
                  or any other person takes any action to declare Section 9 of
                  this Agreement void or enforceable, or institutes any
                  litigation or other legal action designed to deny, diminish or
                  to recover from you the benefits entitled to be provided to
                  you under Section 9, and that you have complied with all your
                  obligations under this Agreement, the Company authorizes you
                  to retain counsel of your choice, at the expense of the
                  Company as provided in this Section 9(e)(ix), to represent you
                  in connection with the initiation or defense of any pre-suit
                  settlement negotiations, litigation or other legal action,
                  whether such action is by or against the Company or any
                  Director, officer, shareholder, or other person affiliated
                  with the Company, in any jurisdiction. Notwithstanding any
                  existing or prior attorney-client relationship between the
                  Company and such counsel, the Company consents to you entering
                  into an attorney-client relationship with such counsel, and in
                  that connection the Company and you agree that a confidential
                  relationship shall exist between you and such counsel, except
                  with respect to any fee and expense invoices generated by such
                  counsel. The reasonable fees and expenses of counsel selected
                  by you as hereinabove provided shall be paid or reimbursed to
                  you by the Company on a regular, periodic basis upon
                  presentation by you of a statement or statements prepared by
                  such counsel in accordance with its customary practices, up to
                  a maximum aggregate amount of $50,000. Any legal expenses
                  incurred by the Company by reason of any dispute between the
                  parties as to enforceability of Section 9 or the terms
                  contained in Section 9(f), notwithstanding the outcome of any
                  such dispute, shall be the sole responsibility of the Company,
                  and the Company shall not take any action to seek
                  reimbursement from you for such expenses.

                  (f) The noncompetition periods described in Section 8 of this
Agreement shall be suspended while you engage in any activities in breach of
this Agreement. In the event that a court grants injunctive relief to the
Company for your failure to comply with Section 8, the noncompetition period
shall begin again on the date such injunctive relief is granted.

                                      -11-
<PAGE>

                  (g) Nothing contained in this Section 9 shall be construed as
limiting your obligations under Sections 6, 7, or 8 of this Agreement concerning
Confidential Information, Inventions, or Noncompetition and Nonsolicitation.

         10. REMEDIES; VENUE; PROCESS.

                  (a) You hereby acknowledge and agree that the Confidential
Information disclosed to you prior to and during the term of this Agreement is
of a special, unique and extraordinary character, and that any breach of this
Agreement will cause the Company irreparable injury and damage, and consequently
the Company shall be entitled, in addition to all other legal and equitable
remedies available to it, to injunctive and any other equitable relief to
prevent or cease a breach of Sections 6, 7, or 8 of this Agreement without
further proof of harm and entitlement; that the terms of this Agreement, if
enforced by the Company, will not unduly impair your ability to earn a living or
pursue your vocation; and further, that the Company may cease paying any
compensation and benefits under Section 9 if you fail to comply with this
Agreement, without restricting the Company from other legal and equitable
remedies. The parties agree that the prevailing party in litigation concerning a
breach of this Agreement shall be entitled to all costs and expenses (including
reasonable legal fees and expenses) which it incurs in successfully enforcing
this Agreement and in prosecuting or defending any litigation (including
appellate proceedings) concerning a breach of this Agreement.

                  (b) Except for actions brought under Section 9(b) of this
Agreement, the parties agree that jurisdiction and venue in any action brought
pursuant to this Agreement to enforce its terms or otherwise with respect to the
relationships between the parties shall properly lie in either the United States
District Court for the Southern District of Ohio, Eastern Division, Columbus,
Ohio, or the Court of Common Pleas of Franklin County, Ohio. Such jurisdiction
and venue is exclusive, except that the Company may bring suit in any
jurisdiction and venue where jurisdiction and venue would otherwise be proper if
you may have breached Sections 6, 7, or 8 of this Agreement. The parties further
agree that the mailing by certified or registered mail, return receipt
requested, of any process required by any such court shall constitute valid and
lawful service of process against them, without the necessity for service by any
other means provided by statute or rule of court.

         11. EXIT INTERVIEW. Prior to Employment Separation, you shall attend an
exit interview if desired by the Company and shall, in any event, inform the
Company at the earliest possible time of the identity of your future employer
and of the nature of your future employment.

         12. NO WAIVER. Any failure by the Company to enforce any provision of
this Agreement shall not in any way affect the Company's right to enforce such
provision or any other provision at a later time.

         13. SAVING. If any provision of this Agreement is later found to be
completely or partially unenforceable, the remaining part of that provision of
any other provision of this Agreement shall still be valid and shall not in any
way be affected by the finding. Moreover, if any provision is for any reason
held to be unreasonably broad as to time, duration, geographical scope,

                                      -12-
<PAGE>

activity or subject, such provision shall be interpreted and enforced by
limiting and reducing it to preserve enforceability to the maximum extent
permitted by law.

         14. NO LIMITATION. You acknowledge that your employment by the Company
may be terminated at any time by the Company or by you with or without cause in
accordance with the terms of this Agreement. This Agreement is in addition to
and not in place of other obligations of trust, confidence and ethical duty
imposed on you by law.

         15. GOVERNING LAW. This Agreement shall be interpreted and enforced in
accordance with the laws of the State of Ohio without reference to its choice of
law rules.

         16. FINAL AGREEMENT. This Agreement replaces any existing agreement
between you and the Company relating to the same subject matter and may be
modified only by an agreement in writing signed by both you and a duly
authorized representative of the Company.

         17. FURTHER ACKNOWLEDGMENTS. YOU ACKNOWLEDGE THAT YOU HAVE RECEIVED A
COPY OF THIS AGREEMENT, THAT YOU HAVE READ AND UNDERSTOOD THIS AGREEMENT, THAT
YOU UNDERSTAND THIS AGREEMENT AFFECTS YOUR RIGHTS, AND THAT YOU HAVE ENTERED
INTO THIS AGREEMENT VOLUNTARILY.

                                   APPLIED INNOVATION INC.

                                   By:
                                      -----------------------------------------
                                        Robert L. Smialek,
                                        President and Chief Executive Officer

                                   EXECUTIVE:

                                   --------------------------------------------
                                           Karl Fox<PAGE>

                                                                     Exhibit 4.1

                       AMENDMENT NO. 5 TO CREDIT AGREEMENT

       THIS AMENDMENT NO. 5 TO CREDIT AGREEMENT, is dated as of September 28,
2001 (this "Amendment"), among the following:

       (i) ALLEN TELECOM INC., a Delaware corporation (herein, together with its
successors and assigns, the "Borrower");

       (ii) the Lenders party to the Credit Agreement, as hereinafter defined;

       (iii) BANK ONE, MICHIGAN (successor in interest to NBD Bank) as a Lender
and as Documentation Agent (the "Documentation Agent"); and

       (iv) KEYBANK NATIONAL ASSOCIATION, a national banking association, as a
Lender and as the Administrative Agent and the Collateral Agent under the Credit
Agreement (the "Administrative Agent"):

       PRELIMINARY STATEMENTS:

       (1) The Borrower, the Lenders, the Documentation Agent and the
Administrative Agent are parties to the Credit Agreement, dated as of
December 31, 1998 (as amended and as the same may from time to time be further
amended, restated or otherwise modified, the "Credit Agreement"; the terms
defined therein are used herein as so defined).

       (2) The parties hereto desire to modify certain terms and provisions of
the Credit Agreement, all as more fully set forth below.

       NOW, THEREFORE, the parties hereby agree as follows:

       Section 1. AMENDMENTS.

       1.1. AMENDED DEFINITIONS. Section 1.1 of the Credit Agreement is hereby
amended to delete the definitions of "APPLICABLE FACILITY FEE RATE", "PERMITTED
ACQUISITION" and "UCC" therefrom and to insert in place thereof, respectively,
the following:

            "APPLICABLE FACILITY FEE RATE" shall mean:

            (a) for any date prior to September 28, 2001, as determined in
       accordance with section 4.1(a)(ii) of this Agreement as in effect prior
       to September 28, 2001;

            (b) from September 28, 2001 through November 30, 2001, 50 basis
       points; and

            (c) commencing with the fiscal quarter of the Borrower ended
       September 30, 2001, and continuing with each fiscal quarter thereafter,
       the number of basis points determined by the Administrative Agent in
       accordance with the Pricing Grid Table, based upon the Leverage Ratio.
       Changes in the Applicable Facility Fee Rate shall become effective on the
       first day of the month following the receipt by the Administrative Agent,
       pursuant to section 8.1(a) or (b) of the financial statements of the
       Borrower; PROVIDED,
<PAGE>

       HOWEVER, that, notwithstanding the foregoing, unless otherwise agreed by
       the Required Lenders, during any period when (i) the Borrower shall have
       failed to timely deliver its financial statements referred to in Section
       8.1(a) or (b), (ii) a Default under section 10.1(a) shall have occurred
       and be continuing, or (iii) an Event of Default shall have occurred and
       be continuing, the Applicable Facility Fee Rate shall be the highest
       number of basis points indicated therefor in the Pricing Grid Table,
       regardless of the Leverage Ratio at such time. Any changes in the
       Applicable Facility Fee Rate shall be determined by the Administrative
       Agent in accordance with the above provisions and the Administrative
       Agent shall promptly provide notice of such determinations to the
       Borrower and the Lenders, which determinations by the Administrative
       Agent shall be conclusive and binding absent manifest error.

            "PERMITTED ACQUISITION" shall mean and include any Acquisition that:

            (a) is not actively opposed by the Board of Directors (or similar
       governing body) of the selling Person or the Person whose equity
       interests are to be acquired, UNLESS all of the Lenders specifically
       approve or consent to such Acquisition in writing;

            (b) if such Acquisition involves cash consideration, including cash
       consideration to be used to prepay or otherwise retire any Indebtedness
       of the business being acquired, whether such cash consideration is
       payable immediately or on a deferred or contingent basis ("CASH
       CONSIDERATION"), then, unless the Required Lenders specifically approve
       or consent to such Acquisition in writing, (i) for any period prior to
       September 28, 2001, the aggregate Cash Consideration for such Acquisition
       does not and will not aggregate in excess of $20,000,000, and (ii) on and
       after September 28, 2001, no Acquisition may be made by the Borrower if
       such Acquisition involves any Cash Consideration, EXCEPT the Borrower may
       make the Target Acquisition so long as (A) the Target Acquisition shall
       have been completed on or before December 31, 2001, and (B) prior to or
       concurrently with the consummation of the Target Acquisition, the
       Borrower shall have received the proceeds of the issuance of additional
       equity of the Borrower, which proceeds shall have been (1) in an amount
       greater than or equal to 2.5 times the Cash Consideration to be paid in
       connection with the Target Acquisition, and (2) applied by the Borrower
       (after deducting taxes, fees and expenses actually paid in connection
       with the issuance of such equity) on the date such proceeds are received
       to (y) repay any Loans outstanding on such date, or (z) pay all or a
       portion of the Cash Consideration for the Target Acquisition;

            (c) if such Acquisition results in any new Subsidiary or
       Subsidiaries of the Borrower, there are no holder or holders of minority
       equity interests therein; and

            (d) after giving effect thereto, the Borrower would be in
       compliance, on a PRO FORMA basis, with the financial covenants contained
       in sections 9.8, 9.9, 9.10 and 9.11.

       The term Permitted Acquisition does not include any loans, advances or
       minority investments otherwise permitted pursuant to section 9.5.

            "UCC" shall mean the Uniform Commercial Code, as in effect from time
       to time in the State of Ohio.

                                       2
<PAGE>

       1.2. NEW DEFINITIONS. Section 1.1 of the Credit Agreement is hereby
amended to add the following new definitions thereto:

            "ADJUSTED COVENANT DATE" shall mean the date upon which the Target
       Acquisition shall have been consummated in accordance with section 9.2(c)
       hereof.

            "APPLICABLE MARGIN" shall mean:

            (a) for any date prior to September 28, 2001, as determined in
       accordance with section 2.8(h) of this Agreement as in effect prior to
       September 28, 2001;

            (b) from September 28, 2001 through November 30, 2001, (i) 250 basis
       points for General Revolving Loans that are Eurocurrency Loans, and (ii)
       50 basis points for General Revolving Loans that are Prime Rate Loans;
       and

            (c) commencing with the fiscal quarter of the Borrower ended
       September 30, 2001, and continuing with each fiscal quarter thereafter,
       the number of basis points determined by the Administrative Agent in
       accordance with the Pricing Grid Table, based upon the Leverage Ratio.
       Changes in the Applicable Margin shall become effective on the first day
       of the month following the receipt by the Administrative Agent, pursuant
       to section 8.1(a) or (b) of the financial statements of the Borrower;
       PROVIDED, HOWEVER, that, notwithstanding the foregoing, unless otherwise
       agreed by the Required Lenders, during any period when (i) the Borrower
       shall have failed to timely deliver its financial statements referred to
       in section 8.1(a) or (b), (ii) a Default under section 10.1(a) shall have
       occurred and be continuing, or (iii) an Event of Default shall have
       occurred and be continuing, the Applicable Margin for Loans shall be the
       highest number of basis points indicated therefor in the Pricing Grid
       Table, regardless of the Leverage Ratio at such time. Any changes in the
       Applicable Margin shall be determined by the Administrative Agent in
       accordance with the above provisions and the Administrative Agent shall
       promptly provide notice of such determinations to the Borrower and the
       Lenders, which determinations by the Administrative Agent shall be
       conclusive and binding absent manifest error.

            "CONSOLIDATED CURRENT ASSETS" shall mean, at any date, current
       assets, as determined on a Consolidated basis and in accordance with
       GAAP.

            "CONSOLIDATED CURRENT LIABILITIES" shall mean, at any date, current
       liabilities, as determined on a Consolidated basis and in accordance with
       GAAP, PROVIDED THAT, included in Consolidated Current Liabilities shall
       be (i) the aggregate outstanding principal amount of all Loans, (ii) the
       aggregate amount of the Letter of Credit Outstandings, and (iii) the
       aggregate outstanding principal amount of the Senior Notes.

            "FIXED CHARGE COVERAGE RATIO" shall mean, for the most recently
       completed Testing Period, the ratio of (a) Consolidated EBITDA for such
       Testing Period, LESS Consolidated Capital Expenditures for such Testing
       Period, to (b) the sum of Consolidated Interest Expense, Consolidated
       Income Tax Expense and the aggregate amount expended in cash or property
       (other than capital stock of the Borrower which is not Redeemable Stock)
       for Dividends, for such Testing Period, PLUS the amount representing the
       current

                                       3
<PAGE>

       portion (determined in accordance with GAAP) of its Consolidated Total
       Long Term Debt as of the end of such Testing Period.

            "INTEREST COVERAGE RATIO" shall mean, for the most recently
       completed Testing Period, the ratio of (a) Consolidated EBIT to (b)
       Consolidated Interest Expense.

            "LEVERAGE RATIO" shall mean, for the most recently completed Testing
       Period, the ratio of (a) Consolidated Total Debt as of the end of the
       most recently completed fiscal quarter to (b) Consolidated EBITDA.

            "LIQUIDITY RATIO" shall mean, for the most recently completed
       Testing Period, the ratio of (a) Consolidated Current Assets to (b)
       Consolidated Current Liabilities.

            "PRICING GRID TABLE" shall mean the following pricing grid table:

                               PRICING GRID TABLE
                           (Expressed in Basis Points)

<TABLE>
<CAPTION>
       -------------------------------------------------------------------------------------------------------------

                                              Applicable Margin       Applicable Margin             Applicable
                                              for Eurocurrency         for Prime Rate            Facility Fee Rate
                 Leverage Ratio                     Loans                   Loans

       -------------------------------------------------------------------------------------------------------------
<S>                                           <C>                     <C>                      <C>
         Greater than 4.00 to 1.00                 300.00                    100.00                   50.00
       -------------------------------------------------------------------------------------------------------------
         Greater than 3.50 to 1.00                 275.00                     75.00                   50.00
         but less than or equal to
         4.00 to 1.00
       -------------------------------------------------------------------------------------------------------------
         Greater than 3.00 to 1.00                 250.00                     50.00                   50.00
         but less than or equal to
         3.50 to 1.00

       -------------------------------------------------------------------------------------------------------------
         Greater than 2.50 to 1.00                 225.00                      0.00                   37.50
         but less than or equal to
         3.00 to 1.00
       -------------------------------------------------------------------------------------------------------------
         Greater than 2.00 to 1.00                 200.00                      0.00                   37.50
         but less than or equal to
         2.50 to 1.00
       -------------------------------------------------------------------------------------------------------------
         Less than or equal to 2.00                175.00                      0.00                   25.00
         to 1.00
       -------------------------------------------------------------------------------------------------------------
</TABLE>

            "TARGET ACQUISITION" shall mean the acquisition by the Borrower of
       substantially all of the net assets of the Person identified by the
       Borrower in the materials distributed to the Lenders on September 19,
       2001, on terms and conditions consistent with those set forth in such
       materials.

            1.3. DELETED DEFINITIONS. Section 1.1 of the Credit Agreement is
hereby amended to delete the following definition: "APPLICABLE
EUROCURRENCY MARGIN".

            1.4. AMENDMENT TO SECTION 2.8. Section 2.8 of the Credit Agreement
is hereby amended to delete subparts (a), (b) and (h) therefrom and to
insert in place thereof the following:

                                       4
<PAGE>

            (a) INTEREST ON PRIME RATE LOANS. The unpaid principal amount of
       each General Revolving Loan or Swing Line Revolving Loan that is a Prime
       Rate Loan shall bear interest from the date of the Borrowing thereof
       (including any date of Conversion or Redenomination thereof) until
       maturity (whether by acceleration or otherwise) at a fluctuating rate per
       annum which shall at all times be equal to the Applicable Margin PLUS the
       Prime Rate from time to time in effect.

            (b) INTEREST ON EUROCURRENCY LOANS. The unpaid principal amount of
       each General Revolving Loan that is a Eurocurrency Loan shall bear
       interest from the date of the Borrowing thereof (including any
       Continuation, Conversion or Redenomination thereof) until maturity
       (whether by acceleration or otherwise) at a rate per annum which shall at
       all times during the Interest Period applicable thereto be the Applicable
       Margin for such Eurocurrency Loan PLUS the relevant Adjusted Eurocurrency
       Rate for such Interest Period.

            (h) [Intentionally Deleted].

       1.5. AMENDMENT TO SECTION 4.1. The Credit Agreement is hereby amended to
delete subpart (ii) from section 4.1(a) thereof and to insert in place thereof
the following:

                (ii) [Intentionally Deleted].

       1.6. AMENDMENT TO CERTAIN FINANCIAL COVENANTS. Sections 9.6, 9.7, 9.8,
9.9, 9.10 and 9.11 of the Credit Agreement are hereby amended such that, for any
date prior to September 30, 2001, the Borrower shall be required to comply with
such sections as in effect prior to the Amendment Effective Date (as defined
below), and, on September 30, 2001 and thereafter, such sections shall be
amended in their entirety to read, respectively, as follows:

            9.6. DIVIDENDS, ETC. The Borrower will not (a) directly or
       indirectly declare, order, pay or make any dividend (other than dividends
       payable solely in capital stock of the Borrower) or other distribution on
       or in respect of any capital stock of any class of the Borrower, whether
       by reduction of capital or otherwise (collectively "DIVIDENDS"), or (b)
       directly or indirectly make, or permit any of its Subsidiaries to
       directly or indirectly make, any purchase, redemption, retirement or
       other acquisition of any capital stock of any class of the Borrower
       (other than for a consideration consisting solely of capital stock of the
       same class of the Borrower) or of any warrants, rights or options to
       acquire or any securities convertible into or exchangeable for any
       capital stock of the Borrower (collectively, "STOCK REPURCHASES"),
       UNLESS, immediately prior to and immediately after giving effect to any
       such action, (i) no Default under section 10.1(a) or Event of Default
       shall have occurred and be continuing, (ii) the Borrower shall be in
       compliance with section 9.7, (iii) the Leverage Ratio shall be less than
       3.00 to 1.00, and (iii) the Interest Coverage Ratio shall be greater than
       2.00 to 1.00.

            9.7. MINIMUM CONSOLIDATED NET WORTH. The Borrower will not permit
       its Consolidated Net Worth at any time to be less than $216,585,000,
       EXCEPT that (i) effective as of the end of the Borrower's fiscal quarter
       ended on or nearest to June 30, 2001, and as of the end of each fiscal
       quarter thereafter, the foregoing amount (as it may from time to time be
       adjusted as herein provided) shall be positively increased by 50% of the

                                       5
<PAGE>

       Consolidated Net Income of the Borrower for the fiscal quarter ended on
       such date, if any (there being no reduction in the case of any such
       Consolidated Net Income which reflects a deficit), (ii) the foregoing
       amount (as it may from time to time be adjusted as herein provided) shall
       be increased by an amount equal to 75% of the cash proceeds (net of
       underwriting discounts and commissions and other customary fees and costs
       associated therewith) from any sale or issuance of equity by the Borrower
       after June 30, 2001 (other than any sale or issuance to management or
       employees or employee benefit plans pursuant to employee benefit plans of
       general application), (iii) the foregoing amount (as it may from time to
       time be adjusted as herein provided) shall be positively increased by 75%
       of the increase in Consolidated Net Worth attributable to the issuance,
       subsequent to June 30, 2001, of common stock or other equity interests as
       consideration in any Acquisitions permitted under section 9.2, and (iv)
       the foregoing amount (as it may from time to time be adjusted as herein
       provided) shall be decreased (but not by more than a maximum of
       $50,000,000) by 100% of the aggregate value of the consideration paid by
       the Borrower and its Subsidiaries in cash or property for Stock
       Repurchases made after December 31, 1999.

            9.8. LEVERAGE RATIO. The Borrower shall not permit at any time the
       Leverage Ratio to exceed the maximum permitted for any Testing Period
       (depending upon whether or not the Adjusted Covenant Date shall have
       occurred) pursuant to the table set forth below for the time period set
       forth below:

<TABLE>
<CAPTION>
                                                                   MAXIMUM AMOUNT               MAXIMUM AMOUNT
                                                               PERMITTED PRIOR TO THE       PERMITTED ON AND AFTER
                            TIME PERIOD                          ADJUSTED COVENANT           THE ADJUSTED COVENANT
                                                                        DATE                         DATE
       ----------------------------------------------------------------------------------------------------------------
<S>                                                            <C>                          <C>
         September 30, 2001 through December 30, 2001               3.60 to 1.00                 3.15 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2001 through March 30, 2002                   3.75 to 1.00                 3.40 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2002 through June 29, 2002                       4.25 to 1.00                 3.75 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2002 through September 29, 2002                   4.30 to 1.00                 3.75 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         September 30, 2002 through December 30, 2002               3.75 to 1.00                 3.15 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2002 through March 30, 2003                   3.45 to 1.00                 3.00 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2003 through June 29, 2003                       3.10 to 1.00                 3.00 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2003 and thereafter                               3.00 to 1.00                 3.00 to 1.00
       ----------------------------------------------------------------------------------------------------------------
</TABLE>

            9.9. MINIMUM CONSOLIDATED EBITDA. The Borrower shall not permit at
       any time Consolidated EBITDA for its Testing Period most recently ended
       to be less than the minimum amount required (depending upon whether or
       not the Adjusted Covenant Date shall have occurred) pursuant to the table
       set forth below for the time period set forth below:

<TABLE>
<CAPTION>
       ----------------------------------------------------------------------------------------------------------------
                                                                  MINIMUM AMOUNT                 MINIMUM AMOUNT
                                                               REQUIRED PRIOR TO THE          REQUIRED ON AND AFTER
                          TIME PERIOD                            ADJUSTED COVENANT            THE ADJUSTED COVENANT
                                                                        DATE                          DATE
       ----------------------------------------------------------------------------------------------------------------
<S>                                                            <C>                            <C>
         September 30, 2001 through December 30, 2001               $48,200,000                   $47,200,000
       ----------------------------------------------------------------------------------------------------------------

</TABLE>
                                       6
<PAGE>

<TABLE>
<S>                                                            <C>                            <C>
         December 31, 2001 through March 30, 2002                   $43,000,000                   $41,700,000
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2002 through June 29, 2002                       $37,800,000                   $37,700,000
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2002 through September 29, 2002                   $37,400,000                   $38,100,000
       ----------------------------------------------------------------------------------------------------------------
         September 30, 2002 through December 30, 2002               $40,500,000                   $41,400,000
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2002 through March 30, 2003                   $43,600,000                   $47,500,000
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2003 through June 29, 2003                       $48,000,000                   $55,000,000
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2003 through September 29, 2003                   $50,000,000                   $55,000,000
       ----------------------------------------------------------------------------------------------------------------
         September 30, 2003 through December 30, 2003               $52,500,000                   $55,000,000
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2003 and thereafter                           $55,000,000                   $55,000,000
       ----------------------------------------------------------------------------------------------------------------
</TABLE>

            9.10. FIXED CHARGE COVERAGE RATIO. The Borrower shall not permit at
       any time the Fixed Charge Coverage Ratio to be less than the minimum
       required for any Testing Period (depending upon whether or not the
       Adjusted Covenant Date shall have occurred) pursuant to the table set
       forth below for the time period set forth below:

<TABLE>
<CAPTION>
       ----------------------------------------------------------------------------------------------------------------
                                                                 MINIMUM REQUIRED              MINIMUM REQUIRED ON
                                                               PRIOR TO THE ADJUSTED         AND AFTER THE ADJUSTED
                        TIME PERIOD                                COVENANT DATE                 COVENANT DATE
       ----------------------------------------------------------------------------------------------------------------
<S>                                                            <C>                           <C>
         September 30, 2001 through December 30, 2001               1.70 to 1.00                 1.50 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2001 through March 30, 2002                   1.25 to 1.00                 1.25 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2002 through June 29, 2002                       1.07 to 1.00                 1.15 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2002 through September 29, 2002                   1.00 to 1.00                 1.10 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         September 30, 2002 through December 30, 2002               1.00 to 1.00                 1.10 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2002 through March 30, 2003                   1.03 to 1.00                 1.25 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2003 through June 29, 2003                       1.15 to 1.00                 1.40 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2003 through September 29, 2003                   1.25 to 1.00                 1.45 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         September 30, 2003 through December 30, 2003               1.30 to 1.00                 1.50 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2003 and thereafter                           1.50 to 1.00                 1.50 to 1.00
       ----------------------------------------------------------------------------------------------------------------
</TABLE>

            9.11. LIQUIDITY RATIO. The Borrower shall not permit at any time the
       Liquidity Ratio to be less than the minimum required for any Testing
       Period (depending upon whether or not the Adjusted Covenant Date shall
       have occurred) pursuant to the table set forth below for the time period
       set forth below:

<TABLE>
<CAPTION>
       ----------------------------------------------------------------------------------------------------------------
                                                                 MINIMUM REQUIRED            MINIMUM REQUIRED ON
                                                               PRIOR TO THE ADJUSTED        AND AFTER THE ADJUSTED
                              TIME PERIOD                          COVENANT DATE                COVENANT DATE
       ----------------------------------------------------------------------------------------------------------------
<S>                                                            <C>                          <C>
         September 30, 2001 through December 30, 2001               0.95 to 1.00                 1.05 to 1.00
       ----------------------------------------------------------------------------------------------------------------
</TABLE>

                                       7
<PAGE>

<TABLE>
<S>                                                            <C>                          <C>
         December 31, 2001 through March 30, 2002                   0.95 to 1.00                 1.05 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2002 through June 29, 2002                       0.95 to 1.00                 1.05 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2002 through September 29, 2002                   0.95 to 1.00                 1.05 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         September 30, 2002 through December 30, 2002               0.95 to 1.00                 1.10 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2002 through March 30, 2003                   0.95 to 1.00                 1.10 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         March 31, 2003 through June 29, 2003                       1.00 to 1.00                 1.15 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         June 30, 2003 through September 29, 2003                   1.00 to 1.00                 1.20 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         September 30, 2003 through December 30, 2003               1.05 to 1.00                 1.20 to 1.00
       ----------------------------------------------------------------------------------------------------------------
         December 31, 2003 and thereafter                           1.05 to 1.00                 1.20 to 1.00
       ----------------------------------------------------------------------------------------------------------------
</TABLE>

       Section 2. REPRESENTATIONS AND WARRANTIES.

       The Borrower represents and warrants as follows:

       2.1. AUTHORIZATION AND VALIDITY OF AMENDMENT. This Amendment has been
duly authorized by all necessary corporate action on the part of the Borrower,
has been duly executed and delivered by a duly authorized officer of the
Borrower, and constitutes the valid and binding agreement of the Borrower,
enforceable against the Borrower in accordance with its terms.

       2.2. REPRESENTATIONS AND WARRANTIES. The representations and warranties
of the Credit Parties contained in the Credit Agreement and in the other Credit
Documents are true and correct in all material respects on and as of the
Amendment Effective Date, as though made on and as of the Amendment Effective
Date, except to the extent that such representations and warranties expressly
relate to an earlier specified date, in which case such representations and
warranties are hereby reaffirmed as true and correct in all material respects as
of the date when made.

       2.3. NO EVENT OF DEFAULT. No Default or Event of Default exists or
hereafter will begin to exist.

       2.4. COMPLIANCE. The Borrower is in full compliance with all covenants
and agreements contained in the Credit Agreement, as amended hereby, and the
other Credit Documents to which it is a party.

       2.5. NO CLAIMS. The Borrower is not aware of any claim or offset against,
or defense or counterclaim to, any of its obligations or liabilities under the
Credit Agreement or any other Credit Document.

       Section 3. RATIFICATIONS.

       Except as expressly modified and superseded by this Amendment, the terms
and provisions of the Credit Agreement are ratified and confirmed and shall
continue in full force and effect.

                                       8
<PAGE>

       Section 4. BINDING EFFECT.

       This Amendment shall become effective on the date set forth in the
opening paragraph of this Amendment (the "Amendment Effective Date"), subject to
the satisfaction of the following conditions on or before such date:

              (a) the Borrower, the Administrative Agent and the Required
       Lenders shall have executed this Amendment;

              (b) the Borrower shall have paid to the Administrative Agent, for
       the pro rata benefit of the Lenders that shall have executed this
       Amendment by 5:00 P.M. (Eastern Daylight Time) on September 28, 2001, an
       amendment fee in an amount equal to (i) 40 basis points times (ii) the
       aggregate amount of the Commitments of all of the Lenders executing this
       Amendment by such time;

              (c) the Borrower shall have paid to the Administrative Agent the
       agent fees set forth in the letter dated as of September 13, 2001 from
       the Administrative Agent to the Borrower;

              (d) the Borrower shall have paid all reasonable legal fees and
       expenses of the Administrative Agent in connection with this Amendment
       and the documents executed in connection therewith; and

              (e) the Borrower shall have provided such other items and shall
       have satisfied such other conditions as may be reasonably required by the
       Administrative Agent and the Lenders.

       Section 5. MISCELLANEOUS.

       5.1. SURVIVAL OF REPRESENTATIONS AND WARRANTIES. All representations and
warranties made in this Amendment shall survive the execution and delivery of
this Amendment, and no investigation by the Administrative Agent or any Lender
or any subsequent Loan or other Credit Event shall affect the representations
and warranties or the right of the Administrative Agent or any Lender to rely
upon them.

       5.2. REFERENCE TO CREDIT AGREEMENT. The Credit Agreement and any and all
other agreements, instruments or documentation now or hereafter executed and
delivered pursuant to the terms of the Credit Agreement as amended hereby, are
hereby amended so that any reference therein to the Credit Agreement shall mean
a reference to the Credit Agreement as amended hereby.

       5.3. SEVERABILITY. Any term or provision of this Amendment held by a
court of competent jurisdiction to be invalid or unenforceable shall not impair
or invalidate the remainder of this Amendment and the effect thereof shall be
confined to the term or provision so held to be invalid or unenforceable.

       5.4. APPLICABLE LAW. This Amendment shall be governed by and construed in
accordance with the laws of the State of Ohio without regard to conflicts of
laws provisions.

                                       9
<PAGE>

       5.5. HEADINGS. The headings, captions and arrangements used in this
Amendment are for convenience only and shall not affect the interpretation of
this Amendment.

       5.6. ENTIRE AGREEMENT. This Amendment is specifically limited to the
matters expressly set forth herein. This Amendment and all other instruments,
agreements and documentation executed and delivered in connection with this
Amendment embody the final, entire agreement among the parties hereto with
respect to the subject matter hereof and supersede any and all prior
commitments, agreements, representations and understandings, whether written or
oral, relating to the matters covered by this Amendment, and may not be
contradicted or varied by evidence of prior, contemporaneous or subsequent oral
agreements or discussions of the parties hereto. There are no oral agreements
among the parties hereto relating to the subject matter hereof or any other
subject matter relating to the Credit Agreement. Except as set forth herein, the
Credit Agreement shall remain in full force and effect and be unaffected hereby.

       5.7. WAIVER OF CLAIMS. The Borrower, by signing below, hereby waives and
releases the Administrative Agent and each of the Lenders and their respective
directors, officers, employees, attorneys, affiliates and subsidiaries from any
and all claims, offsets, defenses and counterclaims of which the Borrower is
aware, such waiver and release being with full knowledge and understanding of
the circumstances and effect thereof and after having consulted legal counsel
with respect thereto.

       5.8. COUNTERPARTS. This Amendment may be executed by the parties hereto
separately in one or more counterparts and by facsimile signature, each of which
when so executed shall be deemed to be an original, but all of which when taken
together shall constitute one and the same agreement.

                      [Remainder of page intentionally left

                                       10
<PAGE>

       5.9. JURY TRIAL WAIVER. EACH OF THE PARTIES TO THIS AMENDMENT HEREBY
IRREVOCABLY WAIVES ALL RIGHT TO A TRIAL BY JURY IN ANY ACTION, PROCEEDING OR
COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS AMENDMENT, THE OTHER CREDIT
DOCUMENTS OR THE TRANSACTIONS CONTEMPLATED HEREBY OR THEREBY. EACH PARTY HERETO
HEREBY (A) CERTIFIES THAT NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY OTHER
PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD NOT,
IN THE EVENT OF LITIGATION, SEEK TO ENFORCE THE FOREGOING WAIVER, AND (B)
ACKNOWLEDGES THAT IT AND THE OTHER PARTIES HERETO HAVE BEEN INDUCED TO ENTER
INTO THIS AMENDMENT BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND
CERTIFICATIONS IN THIS SECTION.

       IN WITNESS WHEREOF, this Amendment has been duly executed and delivered
as of the date first above written.

  ALLEN TELECOM INC.                    KEYBANK NATIONAL ASSOCIATION,
                                          individually as the Swing Line Lender,
  By:_______________________________      a Lender, a Letter of Credit Issuer,
                                          and as the Syndication Agent and
  Name:_____________________________      the Administrative Agent

  Title:____________________________

                                        By:_________________________________
                                           Lawrence A. Mack, Senior Vice
                                           President

  BANK ONE, MICHIGAN                    FIRSTAR BANK, NATIONAL ASSOCIATION
    (formerly  NBD Bank),               (formerly Star Bank,
      individually as a Lender and      National Association)
      as Documentation Agent
                                        By:_________________________________
  By:_______________________________
                                        Name:_______________________________
  Name:_____________________________
                                        Title:______________________________
  Title:____________________________

  FIFTH THIRD BANK, NORTHEASTERN OHIO   LaSALLE BANK NATIONAL ASSOCIATION
                                        (formerly LaSalle National Bank)
  By:_______________________________

  Name:_____________________________    By:_________________________________

  Title:____________________________    Name:_______________________________

                                        Title:______________________________

                                       11
<PAGE>

  DRESDNER BANK AG,
  New York and Grand Cayman Branches

  By:_______________________________

  Name:_____________________________

  Title:____________________________

  and:______________________________

  Name:_____________________________

  Title:____________________________

                                       12
<PAGE>
================================================================================
================================================================================

                               ALLEN TELECOM INC.
                                 as the Borrower

                            THE LENDERS NAMED HEREIN
                                 as the Lenders

                               BANK ONE, MICHIGAN
                           as the Documentation Agent

                                       and

                          KEYBANK NATIONAL ASSOCIATION
                           as the Administrative Agent

                              ---------------------

                                 AMENDMENT NO. 5
                                   dated as of
                               September 28, 2001
                                       to
                              the CREDIT AGREEMENT
                                   dated as of
                                December 31, 1998

                              ---------------------

================================================================================
================================================================================

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