Document:

CONVERTIBLE DEBENTURE PURCHASE AGREEMENT made the 29th day of December, 1999.

BETWEEN:

         WI-LAN INC., a body corporate, incorporated pursuant to the laws of the
         Province of Alberta (hereinafter referred to as "Wi-LAN")

                                                               OF THE FIRST PART

AND

         DIGITAL TRANSMISSION SYSTEMS, INC., a body corporate, incorporated
         pursuant to the laws of the State of Delaware (hereinafter referred to
         as "DTS")

                                                              OF THE SECOND PART

         WHEREAS DTS has agreed to create, sell and issue and Wi-LAN has agreed
to purchase and acquire, certain securities of DTS upon the terms and conditions
set forth herein;

         AND WHEREAS DTS has agreed to grant to Wi-LAN an option to acquire
certain securities of DTS upon the terms and conditions set forth herein;

         AND WHEREAS DTS has agreed to enter into this Agreement and provide
certain representations, warranties and covenants to Wi-LAN in support and in
furtherance of Wi-LAN's agreement to enter into the Related Agreements.

         In consideration of the premises, covenants and agreements herein and
other good and valuable consideration (the receipt and sufficiency of which is
hereby acknowledged), the parties hereto covenant and agree as follows:

                                    ARTICLE 1
                                 INTERPRETATION

1.1      Definitions

         In this Agreement, unless the context otherwise requires:

(a)      "Agreement" means this agreement, including the recitals, as amended or
         supplemented from time to time, and "hereby", "hereof", "herein",
         "hereunder", "herewith", "hereto" and similar terms refer to this
         Agreement and not to any particular provision of this Agreement;

(b)      "business day" means a day, other than a Saturday, Sunday or statutory
         holiday, when banks are generally open for the transaction of banking
         business in the City of Calgary;

(c)      "Closing" means the closing of the transactions contemplated herein;

(d)      "Closing Time" means 2:00 p.m. (Calgary time), or such other time as
         may be agreed upon by the parties hereto, on the Initial Issue Date,
         the Second Issue Date, the Third Issue Date, the Fourth Issue Date and
         any subsequent Issue Date;

(e)      "Convertible Debenture" means a subordinated debenture of DTS
         substantially in the form of the existing DTS debenture in the
         principal amount of U.S.$2,000,000 owned by Finova Mezzanine Capital
         Inc. excluding Section 1.2, Article 2, Article 3 and Article 4 thereof,
         which subordinated debenture shall have a three year term, have an
         interest rate of 10% per annum (15% after default) and the principal
         and accrued interest of which shall be convertible into DTS Shares on
         the basis of U.S.$1.00 per share;

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(f)      "DTS Material Adverse Effect" means any change or effect that is
         materially adverse to the condition (financial or otherwise), business,
         assets or results of operations, of DTS and its Subsidiaries taken as a
         whole or adversely affects the ability of DTS to consummate the
         transactions contemplated by this Agreement in any material respect or
         materially impairs or delays DTS's ability to perform its obligations
         hereunder;

(g)      "DTS Shares" means the common shares in the capital stock of the
         Corporation, as constituted on the date hereof;

(h)      "Encumbrance" includes, without limitation, any mortgage, pledge,
         assignment, charge, lien, security interest, claim, trust, royalty,
         carried, working, participation, net profits interest or other third
         party interest and any agreement, option, right or privilege (whether
         by law, contract or otherwise) capable of becoming any of the
         foregoing;

(i)      "Finova" means Finova Mezzanine Capital Inc., a body corporate,
         incorporated pursuant to the laws of Tennessee;

(j)      "Fourth Issue Date" means April 1, 2000 or such earlier or later date
         as Wi-LAN and DTS may agree for the closing of the U.S.$300,000
         principal amount of Convertible Debentures;

(k)      "Initial Issue Date" means January 7, 2000, or such earlier or later
         date or dates as Wi-LAN and DTS may agree for the closing of the first
         U.S.$400,000 principal amount of Convertible Debentures, and "Issue
         Date" means such date or dates as Wi-LAN may specify pursuant to the
         exercise of the purchase option granted to it pursuant to section 2.2;

(l)      "Lien" means, with respect to any asset, any mortgage, lien, pledge,
         charge, security interest or encumbrance or right of another to or
         adverse claim of any kind in respect of such asset;

(m)      "MicroTel" means MicroTel International, Inc., a body corporate,
         incorporated pursuant to the laws of the State of Delaware;

(n)      "person" includes an individual, partnership, firm, trust, body
         corporate, governmental authority, unincorporated body of persons or
         association;

(o)      "Promissory Note" means the DTS promissory note in the principal amount
         of U.S.$400,000 and the related DTS security agreement in the form
         attached as Schedule "C";

(p)      "Related Agreement Closing Date" means January 7, 2000 or such later
         date upon which the transactions contemplated by the Related Agreements
         are completed;

(q)      "Related Agreements" means the agreements of even date herewith entered
         into between Wi-LAN and MicroTel and between Wi-LAN and Finova;

(r)      "Second Issue Date" means February 1, 2000 or such earlier or later
         date as Wi-LAN and DTS may agree for the closing of the second
         U.S.$400,000 principal amount of Convertible Debentures;

(s)      "Subsidiary" of any person means (i) any corporation or other entity of
         which securities or other ownership interests having ordinary voting
         power to elect a majority of the board of directors or other persons
         performing similar functions are directly or indirectly owned by such
         person, (ii) any

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                                        3

         partnership of which such person is a general partner and (iii) any
         limited liability company of which such person owns a majority of the
         membership interests in or is its managing member.

(t)      "Third Issue Date" means March 1, 2000 or such earlier or later date as
         Wi-LAN and DTS may agree for the closing of the third U.S.$400,000
         principal amount of Convertible Debentures;

(u)      "Wi-LAN Common Shares" means common shares of Wi-LAN as a class, as
         constituted on the date hereof; and

(v)      "Wi-LAN's Counsel" means Burnet, Duckworth & Palmer or such other legal
         counsel as may be designated by Wi-LAN.

1.2      Schedules

         The following Schedules form part of this Agreement:

         Schedule A        DTS Representations
         Schedule B        List of Intellectual Property owned by DTS
         Schedule C        Form of Promissory Note and Security Agreement

1.3      Headings

         The division of this Agreement into articles, sections and paragraphs
and the insertion of headings are for convenience of reference only and shall
not affect in any way the meaning or interpretation of this Agreement.

1.4      Section References

         Unless the context otherwise requires, references in this Agreement to
an article, section, paragraph, clause, subclause or schedule by number, letter
or otherwise refer to the article, section, subsection, paragraph, clause,
subclause or schedule, respectively, bearing that designation in this Agreement.

1.5      Gender, Plural

         In this Agreement, unless the contrary intention appears, words
importing the singular include the plural and vice versa; words importing gender
shall include all genders.

1.6      Date for Actions

         In the event that the date on which any action is required to be taken
hereunder by any of the parties is not a business day in the place where the
action is required to be taken, such action shall be required to be taken on the
next succeeding day which is a business day in such place.

1.7      Enforceability

         All representations and warranties in or contemplated by this Agreement
as to the enforceability of any agreement or document are subject to
enforceability being limited by applicable bankruptcy, insolvency,
reorganization and other laws affecting creditors' rights generally and the
discretionary nature of certain remedies (including specific performance and
injunctive relief).

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                                    ARTICLE 2
                       PURCHASE AND SALE; GRANT OF OPTION

2.1      Agreement to Purchase and Sell

(a)      On the date of execution and delivery of this Agreement, DTS agrees to
         create, sell and enter into with Wi-LAN or its nominee, and Wi-LAN or
         its nominee agree to purchase and acquire from DTS the Promissory Note,
         in consideration for the sum of U.S.$400,000, U.S.$50,000 of which has
         already been advanced to DTS by Wi-LAN.

(b)      On the Initial Issue Date, DTS agrees to create, sell and issue to
         Wi-LAN or its nominee, and Wi-LAN or its nominee agree to purchase and
         acquire from DTS, U.S.$400,000 principal amount of Convertible
         Debentures.

(c)      On the Second Issue Date, DTS agrees to create, sell and issue to
         Wi-LAN or its nominee, and Wi-LAN or its nominee agree to purchase and
         acquire from DTS, U.S.$400,000 principal amount of Convertible
         Debentures.

(d)      On the Third Issue Date, DTS agrees to create, sell and issue to Wi-LAN
         or its nominee, and Wi-LAN or its nominee agree to purchase and acquire
         from DTS, U.S.$400,000 principal amount of Convertible Debentures.

(e)      On the Fourth Issue Date, DTS agrees to create, sell and issue to
         Wi-LAN or its nominee, and Wi-LAN or its nominee agree to purchase and
         acquire from DTS, U.S.$300,000 principal amount of Convertible
         Debentures.

2.2      Option to Purchase Convertible Debentures / DTS Shares

         DTS hereby grants to Wi-LAN or its nominee the right to purchase from
time to time at its election an aggregate of up to U.S.$1,500,000 principal
amount convertible debentures in addition to the purchases provided for in
Section 2.1 above, at a purchase price equal to the principal amount thereof.
The convertible debentures shall be identical to the form of the Convertible
Debenture with the exception that the convertible debentures shall be
convertible into DTS Shares at the average weighted trading price of the DTS
Shares over the last three trading days prior to the exercise of the option by
Wi-LAN. Any such election to purchase additional principal amount of convertible
debentures shall be exercised by written notice from Wi-LAN to DTS, given at any
time on or prior to the second anniversary of the Related Agreement Closing
Date, and setting forth the aggregate principal amount of convertible debentures
to be purchased and the date on which such convertible debentures are to be
delivered, as determined by Wi-LAN but in no event earlier than three nor later
than 20 business days after the date of such notice. Upon the furnishing of such
written notice, Wi-LAN shall be committed to purchase, and DTS shall be
obligated to issue and sell the principal amount of additional convertible
debentures therein indicated, the whole in accordance with and subject to the
provisions hereof. Wi-LAN shall have the further option to elect to purchase DTS
Shares at the average weighted trading price of the DTS Shares over the last
three trading days prior to the exercise of the option by Wi-LAN in lieu of
convertible debentures pursuant to the exercise of the option from time to time
granted pursuant to this section 2.2.

2.3      Execution of Purchase and Sale

         At each Closing Time, Wi-LAN shall wire to DTS an amount equal to the
principal amount of convertible debentures to be purchased against delivery by
DTS to Wi-LAN of the equivalent principal amount of convertible debentures.
Notwithstanding the foregoing, DTS acknowledges that prior to the Initial Issue
Date it will have received from Wi-LAN the sum of U.S.$400,000 as an advance in
respect of Wi-LAN's obligations pursuant to paragraph 2.1(b) and accordingly
shall issue a Convertible Debenture in the principal

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                                        5

amount of U.S.$400,000 pursuant to paragraph 2.1(b) against delivery by Wi-LAN
of the Promissory Note which shall thereafter be deemed to form part of the
U.S.$400,000 Convertible Debenture and be paid in full.

2.4      Non-Closing of Related Agreement Transactions

         If the Related Agreement Closing Date shall not have occurred on or
before January 31, 2000, then, notwithstanding any other term of the Promissory
Note issued to Wi-LAN pursuant to paragraph 2.1(a), the principal amount of such
Promissory Note shall be reduced to U.S.$350,000 and shall be repayable by DTS
to Wi-LAN in 24 equal monthly instalments of U.S.$17,500 commencing March 1,
2000. If the Related Agreement Closing Date shall not have occurred on or before
January 31, 2000, then Wi-LAN shall have the option to convert the principal
amount of the Promissory Note and any accrued interest on the Promissory Note
into an equivalent principal amount of Convertible Debentures.

                                    ARTICLE 3
                      REPRESENTATIONS AND WARRANTIES OF DTS

3.1      Representations and Warranties of DTS

         DTS makes the representations and warranties to Wi-LAN on the attached
Schedule "A".

                                    ARTICLE 4
                    REPRESENTATIONS AND WARRANTIES OF Wi-LAN

4.1      Representations and Warranties of Wi-LAN

         Wi-LAN represents and warrants to DTS that:

(a)      Wi-LAN is duly organized and validly existing under the law of the
         jurisdiction of its incorporation;

(b)      Wi-LAN has all requisite power and authority to enter into this
         Agreement and all documents to be delivered pursuant hereto and to
         perform its obligations hereunder and thereunder;

(c)      this Agreement has been duly authorized, executed and delivered by
         Wi-LAN and all documents to be delivered by Wi-LAN pursuant hereto will
         be duly executed and delivered and this Agreement does and such
         documents will constitute legal, valid and binding obligations of
         Wi-LAN enforceable in accordance with their respective terms.

                                    ARTICLE 5
                           Wi-LAN'S CLOSING CONDITIONS

5.1      Conditions Precedent

         The obligations of Wi-LAN to complete the transactions contemplated
herein at any Closing Time is subject to:

(a)      Wi-LAN being satisfied in its sole discretion with its due diligence
         review of DTS and its assets and operations including, without
         limitation, the financial statements of DTS, the obligations and
         liabilities of DTS, the products and revenue stream of DTS and the
         material agreements of DTS;

(b)      since December 20, 1999 DTS shall have carried on its business in the
         ordinary course of business consistent with past practices and shall
         not have engaged in any material transactions outside the ordinary
         course of business (including increasing long-term debt) except as
         disclosed to and approved by Wi-LAN in writing;

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                                        6

(c)      DTS's issued and outstanding share capital at Closing Time consisting
         of an aggregate of 4,646,221 common shares, 1,314,333 preferred shares,
         warrants entitling the holders thereof to acquire an aggregate of
         2,433,315 common shares at exercise prices ranging from U.S. $0.12 to
         U.S. $9.00 per share, options entitling the holders thereof to acquire
         an aggregate of 1,019,880 common shares at exercise prices ranging from
         U.S. $0.47 to U.S. $13.75 per share and a U.S. $2,000,000 convertible
         debenture entitling the holder thereof to acquire 2,000,000 common
         shares at an exercise price of U.S. $1.00 per share;

(d)      since December 20, 1999 DTS shall not have declared or paid any
         dividends or made any other distributions of any of its shares or
         granted any further options or warrants or any right or privilege
         capable of becoming an option or agreement in respect of its shares;

(e)      the transactions contemplated by the Related Agreements shall have been
         completed;

(f)      the board of directors of DTS being comprised of a majority of Wi-LAN
         representatives;

(g)      all of the MicroTel representatives on the DTS board of directors shall
         have resigned;

(h)      Wi-LAN and DTS shall have entered into a registration rights agreement
         with respect to the registration of all the DTS Shares and all of the
         DTS Shares issuable upon exercise of the securities acquired by Wi-LAN
         pursuant to this Agreement and the Related Agreements, which
         registration rights agreement shall be satisfactory in form and
         substance to Wi-LAN and Wi-LAN's Counsel;

(i)      except as contemplated by this Agreement, there shall not have occurred
         any material change, change of material fact or any development that
         could result in a material change or change of a material fact in the
         business, operations or affairs of DTS;

(j)      DTS's employment agreements with its existing personnel shall remain in
         existence, provided that Wi-LAN, in consultation with DTS, may select
         up to three DTS employees with whom DTS shall enter into new or revised
         employment agreements containing terms acceptable to Wi-LAN;

(k)      DTS shall have entered into a license agreement providing for the
         licensing of DTS's products and technology to Wi-LAN on terms
         acceptable to Wi-LAN;

(l)      there will be no actions, suits or proceedings, whether or not
         purportedly on behalf of DTS, outstanding, pending or threatened by or
         against DTS at law or in equity or before or by any federal,
         provincial, municipal or other governmental department, commission,
         bureau, agency or instrumentality;

(m)      the representations and warranties made by DTS herein shall be true at
         the Closing Time as if made at and as of such time and DTS shall have
         complied with its covenants herein and Wi-LAN shall have received a
         certificate signed by the Chief Executive Officer of DTS confirming
         same;

(n)      all proceedings taken in connection with the transactions contemplated
         by this Agreement, and all documents necessary to the consummation
         thereof, shall be satisfactory in form and substance to Wi-LAN and
         Wi-LAN's Counsel;

(o)      Wi-LAN shall have received the opinion of Sutherland, Asbill & Brennan,
         LLP, counsel for DTS, dated the Related Agreement Closing Date,
         addressed to Wi-LAN, in form and substance satisfactory to Wi-LAN's
         Counsel;

(p)      any consents or approvals required to be obtained from any third party,
         including any holder of indebtedness or any outstanding security of the
         company, and any amendments of agreements which shall be necessary to
         permit the consummation of the transactions contemplated hereby shall
         have been obtained and all such consents or amendments shall be
         satisfactory in form and substance to Wi-LAN and Wi-LAN's Counsel.

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5.2      Waiver of Conditions

         The conditions precedent set forth in Section 5.1 are for the benefit
of Wi-LAN and may be waived, in whole or in part, by Wi-LAN at any time. If any
of the said conditions precedent shall not be complied with or waived as
aforesaid on or before the date required for the fulfilment thereof, Wi-LAN may,
in addition to the other remedies it may have at law or in equity, rescind and
terminate this Agreement by notice to DTS.

                                    ARTICLE 6
                                COVENANTS OF DTS

6.1      Conduct of DTS

         Except as expressly contemplated by this Agreement, from the date
hereof until the Related Agreement Closing Date, DTS and its Subsidiaries shall
conduct their business in the ordinary course consistent with past practice and
shall use their best efforts to preserve intact their business organizations and
relationships with third parties and to keep available the services of their
present officers and key employees. Except as otherwise approved in writing by
Wi-LAN or as expressly contemplated by this Agreement, and without limiting the
generality of the foregoing, from the date hereof until the Related Agreement
Closing Date:

(a)      DTS shall not, and shall not permit any of its Subsidiaries to, adopt
         or propose any change in its Certificate of Incorporation or Bylaws or
         comparable charter or other organization documents;

(b)      DTS shall not, and shall not permit any of its Subsidiaries to, acquire
         or agree to acquire, lease or manage (i) by merging or consolidating
         with, or by purchasing a substantial portion of the assets of, or by
         any other manner, any business or any corporation, partnership, joint
         venture, association or other business organization or division thereof
         or (ii) any assets, other than assets that are immaterial to DTS and
         its Subsidiaries taken as a whole and except for purchases in the
         ordinary course of business consistent with past practice;

(c)      DTS will not, and will not permit its Subsidiaries to, sell, lease,
         license, mortgage or otherwise encumber or subject to any Lien or
         otherwise dispose of any of its properties or assets, or stock or other
         ownership interest in any of its properties or subsidiaries other than
         (i) in the ordinary course of business consistent with past practice
         (ii) pursuant to any agreements existing as of the date hereof, which
         agreements have been disclosed in writing to Wi-LAN; (iii) any Liens
         for taxes not yet due and payable or being contested in good faith by
         appropriate proceedings for which adequate reserves have been provided
         in the consolidated balance sheet of DTS at September 30, 1999 and (iv)
         such mechanics and similar liens, if any, as do not materially detract
         from the value of any of such properties, assets, stock or ownership
         interests or materially interfere with the present use of any of such
         properties or assets;

(d)      DTS shall not declare, set aside, or pay any dividends or make any
         distributions on DTS Shares;

(e)      DTS shall not, and shall not permit any of its Subsidiaries to, (i)
         issue, deliver or sell, or authorize or propose the issuance, delivery
         or sale of, any capital stock of DTS or any DTS Subsidiary Securities
         (as herein defined), or any security convertible into or exercisable
         for either of the foregoing other than the issuance of shares of DTS
         Shares upon the exercise of outstanding rights to acquire DTS Shares
         disclosed in Section 1.5 of Schedule "A"; (ii) split, combine or
         reclassify any capital stock of DTS or any of its Subsidiaries or issue
         or authorize the issuance of any other securities in respect of, in
         lieu of or in substitution for shares of capital stock of DTS or any of
         its Subsidiaries; or (iii) except as required or permitted by this
         Agreement, repurchase, redeem or otherwise acquire any shares of

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         capital stock of DTS or any of its Subsidiaries or any other securities
         thereof or any rights, warrants or options to acquire any such shares
         or other securities;

(f)      except as otherwise expressly permitted hereby, DTS will not make any
         commitment or enter into, or amend, modify, or terminate any contract
         or agreement material to DTS and its Subsidiaries taken as a whole
         except in the ordinary course of business consistent with past
         practice;

(g)      (i) DTS will not, and will not permit any of its Subsidiaries to, incur
         any indebtedness for borrowed money or guarantee any such indebtedness
         of another person, issue or sell any debt securities or warrants or
         other rights to acquire any debt securities of DTS or any of its
         Subsidiaries, guarantee any debt securities of another person, enter
         into any "keep well" or other agreement to maintain any financial
         statement condition of another person or enter into any arrangement
         having the economic effect of any of the foregoing, except for
         borrowings under its line of credit for working capital purposes and
         the endorsement of checks in the normal course of business; or (ii)
         make any loans, advances or capital contributions to, or investments
         in, any other person, other than any direct or indirect wholly owned
         subsidiary of DTS and other than travel and entertainment advances to
         employees in the ordinary course of business consistent with past
         practice;

(h)      DTS will not, and will not permit any of its Subsidiaries to, (i)
         increase the compensation payable or to become payable to its officers,
         directors or key employees, (ii) grant any severance or termination pay
         to officers, directors or key employees; (iii) enter into any
         employment, severance or consulting agreement with any current or
         former director, officer or other employee of DTS or any Subsidiary, or
         (iv) establish, adopt, enter into or amend, any collective bargaining,
         bonus, profit sharing, thrift, compensation stock option, restricted
         stock, pension, retirement, deferred compensation, employment
         termination, severance or other plan, agreement, trust, fund, policy or
         arrangement for the benefit of any current or former director, officer
         or employee;

(i)      DTS will not, and will not permit its Subsidiaries to, (i) make any
         payments or other distributions to its officers, directors or
         affiliates except pursuant to existing compensation arrangements for
         directors or officers of DTS or (ii) enter into any contracts,
         agreements or understandings with its officers, directors or
         affiliates;

(j)      DTS will, and DTS will use its reasonable best efforts to ensure that
         it and each of its Subsidiaries will, use its reasonable best efforts
         to keep or cause to be kept its insurance policies (or substantial
         equivalents) in such amounts duly in force until the Related Agreement
         Closing Date and will give Wi-LAN notice of any material change in its
         insurance policies;

(k)      except in connection with the expenses incurred or to be incurred in
         connection with this Agreement and the transactions contemplated hereby
         or in connection with the payment of corporate administrative and
         overhead expenses consistent with past practice, DTS will not, and will
         not permit its Subsidiaries to, make any individual or series of
         related expenditures (whether capital or otherwise) of over $5,000 or
         enter into any contract that is not terminable by DTS without penalty
         upon 30 days notice;

(l)      DTS will not, and will not permit any of its Subsidiaries to, agree or
         commit to do any of the foregoing; and

(m)      DTS will not, and will not permit any of its Subsidiaries to, take or
         agree to commit to take any action that would make any representation
         and warranty of DTS hereunder inaccurate in any material respect at, or
         as of any time prior to, the Related Agreement Closing Date or which is
         reasonably likely to result in a delay in consummation of the
         transactions contemplated hereby.

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6.2      Access to Information

         From the date hereof until the Related Agreement Closing Date, DTS
shall give Wi-LAN, its counsel, financial advisors, auditors and other
authorized representatives reasonable access to the offices, properties, books
and records of DTS and its Subsidiaries, will furnish to Wi-LAN, its counsel,
financial advisors, auditors and other authorized representatives such financial
and operating data and other information as such persons may reasonably request
and will instruct DTS's employees, counsel and financial advisors to cooperate
with Wi-LAN in its investigation of the business of DTS and its Subsidiaries;
provided that no investigation pursuant to this section or paragraph 5.1(a)
shall affect any representation or warranty given by DTS to Wi-LAN hereunder.
All nonpublic information provided to, or obtained by, Wi-LAN in connection with
the transactions contemplated hereby shall be "Confidential Information" for
purposes of the Confidentiality Agreement previously executed by Wi-LAN and DTS
(the "Confidentiality Agreement").

6.3      Other Offers

         From the date hereof until the Related Agreement Closing Date, DTS and
its Subsidiaries will not, and will use their reasonable best efforts to cause
their officers, directors, employees or other agents not to, directly or
indirectly, (i) take any action to solicit or initiate any DTS Acquisition
Proposal (as defined below) or (ii) unless otherwise required in accordance with
the fiduciary duties of the Board of Directors under applicable law as advised
by independent legal counsel to DTS, engage in negotiations with, or disclose
any nonpublic information relating to DTS or any of its Subsidiaries or afford
access to the properties, books or records of DTS or any of its Subsidiaries to,
any person that may be considering making, or has made, a DTS Acquisition
Proposal or has agreed to endorse any DTS Acquisition Proposal (other than the
transactions contemplated hereby ). DTS will promptly as reasonably practicable
notify Wi-LAN after receipt of any DTS Acquisition Proposal or any indication
that any person is considering making a DTS Acquisition Proposal or any request
for nonpublic information relating to DTS or any of its Subsidiaries or for
access to the properties, books or records of DTS or any of its Subsidiaries by
any person that may be considering making, or has made, a DTS Acquisition
Proposal or that DTS intends to engage in negotiations with, or to provide
information to any such person. DTS shall as promptly as reasonably practicable
provide Wi-LAN with the identity of such person and a reasonable description of
such DTS Acquisition Proposal. For purposes of this Agreement, "DTS Acquisition
Proposal" means any offer or proposal for, or any indication of interest in, (i)
a merger, share exchange or business combination or similar transaction, (ii)
any sale, lease, exchange, transfer or other disposition of 10% or more of the
assets of DTS and its Subsidiaries, taken as a whole, in a single transaction or
series of transactions (whether or not related) or (iii) any tender offer or
exchange offer for 10% or more of the outstanding shares of capital stock of DTS
involving DTS or any of its Subsidiaries or the acquisition of a substantial
portion of the assets of, DTS or any of its Subsidiaries, other than the
transactions contemplated by this Agreement. DTS shall immediately cease and
cause to be terminated, its existing solicitation, activity, discussions or
negotiations with any parties conducted heretofore by DTS or any of its
representatives with respect to a DTS Acquisition Proposal.

6.4      Notices of Certain Events

         The Company shall promptly as reasonably practicable notify Wi-LAN of:
(i) any notice or other communication from any person alleging that the consent
of such person (or another person) is or may be required in connection with the
transactions contemplated by this Agreement or the Related Agreements; (ii) any
notice or other communication from any governmental or regulatory agency or
authority in connection with the transactions contemplated by this Agreement or
the Related Agreements; (iii) any actions, suits, claims, investigations or
proceedings commenced or, to the best of its knowledge threatened against,
relating to or involving or otherwise affecting DTS or any of its Subsidiaries
that, if pending on the date of this Agreement, would have been required to have
been disclosed pursuant to section 1.11 of Schedule "A" or which relate to the
consummation of the transactions contemplated by this Agreement or the Related
Agreements; and (iv) of any fact or occurrence between the date of this
Agreement and the Related Agreement Closing Date of which it becomes aware which
makes any of its representations contained in this Agreement untrue or causes
any breach of its obligations under this Agreement.

<PAGE>

                                       10

                                    ARTICLE 7
                                     CLOSING

7.1      Place of Closing

         Closing shall take place at the offices of Wi-LAN's Counsel at the
Closing Time, or at such other place as may be agreed upon by the parties
hereto.

                                    ARTICLE 8
                                    INDEMNITY

8.1      DTS Indemnity

(a)      DTS shall indemnify and save Wi-LAN harmless against and from all
         liabilities, claims, demands, losses, costs (including, without
         limitation, legal fees and disbursements on a full indemnity basis),
         damages and expenses to which Wi-LAN may be subject or which Wi-LAN may
         suffer or incur, whether under the provisions of any statute or
         otherwise, in any way caused by, or arising directly or indirectly from
         or in consequence of any breach of, default under or non-compliance by
         DTS with any representation, warranty, term, covenant or condition of
         this agreement or in any certificate or other document delivered by or
         on behalf of DTS hereunder or pursuant hereto.

(b)      The rights and remedies of Wi-LAN set forth in paragraph 8.1(a) are to
         the fullest extent possible in law cumulative and not alternative and
         the election by Wi-LAN to exercise any such right or remedy shall not
         be, and shall not be deemed to be, a waiver of any other rights and
         remedies. Wi-LAN shall not be obligated to pursue any claim or remedy
         against any third party including, without limitation, MicroTel or
         Finova, before being entitled to obtain full indemnification from DTS
         pursuant to paragraph 8.1(a).

                                    ARTICLE 9
                                     NOTICES

9.1      Notices

         Any notice, consent, waiver, direction or other communication required
or permitted to be given under this Agreement by a party to any other party
shall be in writing and shall be delivered by hand delivery, facsimile
transmission or (provided that the mailing party does not know and should not
reasonably have known of any disruption or anticipated disruption of postal
service which might affect delivery of the mail) by registered mail (postage
prepaid), addressed to the party to whom the notice is to be given, at its
address for service herein. Any notice, consent, waiver, direction or other
communication aforesaid shall, if hand delivered or delivered by telex or
facsimile transmission, be deemed to have been given and received on the date on
which its was hand delivered or delivered by facsimile transmission to the
address provided herein (if a business day and, if not, the next succeeding
business day) and if sent by registered mail be deemed to have been given and
received on the third business day at the point of delivery following the date
on which it was so sent.

9.2      Address for Service

         The address for service of each of the parties hereto shall be as
follows:

(a)      if to Wi-LAN:

<PAGE>

                                       11

               Wi-LAN Inc.
               Suite 300, 801 Manning Road N.E.
               Calgary, Alberta
               T2E 8J8

               Attention: Hatim Zaghloul, Chairman and Chief Executive Officer

               Telecopy:  (403) 273-5100

(b)      if to DTS:

               Digital Transmission Systems, Inc.
               300 Northwoods Parkway, Building 330
               Norcross, Georgia    30071

               Attention: Andres C. Salazar, Chief Executive Officer

               Telecopy: (770) 798-1325

or such other address as may be designated by notice to the other parties
hereto.

                                   ARTICLE 10
                                  MISCELLANEOUS

10.1     Entire Agreement

         This Agreement, together with documents to be delivered pursuant
hereto, constitutes the entire agreement between the parties hereto, and cancels
and supersedes all prior agreements and understandings between the parties
hereto, with respect to the subject matter hereof.

10.2     Further Assurances

         Each party hereto shall, from time to time, and at all times hereafter,
at the request of the other party hereto, but without further consideration, do
all such further acts and execute and deliver all such further documents and
instruments as shall be reasonably required in order to fully perform and carry
out the terms and intent hereof.

10.3     Survival

         The representations, warranties, covenants and agreements herein and in
any document delivered pursuant hereto shall survive the Closing and remain in
full force and effect provided that no party hereto shall be liable in respect
of any representation or warranty unless the party seeking to rely upon such
representation or warranty shall have given notice to the party who made such
representation or warranty of its intention to make such claim on or before the
date 24 months following the Issue Date.

10.4     Time

         Time shall be of the essence in this Agreement.

10.5     Amendments

         This Agreement may only be amended by a written instrument signed by
the parties hereto.

<PAGE>

                                       12

10.6     Governing Law

         This Agreement shall be governed by, and be construed in accordance
with, the laws of the Province of Alberta and applicable laws of Canada but the
reference to such laws shall not, by conflict of laws rules or otherwise,
require the application of the law of any jurisdiction other than the Province
of Alberta.

10.7     Attornment

         Each party hereto hereby irrevocable attorns to the jurisdiction of the
Courts of the Province of Alberta in respect of all matters arising under or in
relation to this Agreement.

10.8     Severability

         If any one or more of the provisions or parts thereof contained in this
Agreement should be or become invalid, illegal or unenforceable in any respect
in any jurisdiction, the remaining provisions or parts thereof contained herein
shall be and shall be conclusively deemed to be, as to such jurisdiction,
severable therefrom and:

(a)      the validity, legality or enforceability of such remaining provisions
         or parts thereof shall not in any way be affected or impaired by the
         severance of the provisions or parts thereof severed; and

(b)      the invalidity, illegality or unenforceability of any provision or
         party thereof contained in this Agreement in any jurisdiction shall not
         affect or impair such provision or part thereof or any other provisions
         of this Agreement in any other jurisdiction.

10.9     Execution in Counterpart

         This Agreement may be executed in any number of counterparts with the
same effect as if all signatures to the counterparts had signed one document,
all such counterparts shall together constitute, and be construed as, one
instrument and each of such counterparts shall, notwithstanding the date of its
execution, be deemed to bear the date first above written.

10.10    Waiver

         No waiver by any party hereto shall be effective unless in writing and
any waiver shall affect only the matter, and the occurrence thereof,
specifically identified and shall not extend to any other matter or occurrence.

10.11    Enurement

         This Agreement shall enure to the benefit of and be binding upon the
parties hereto and their respective successors and assigns.

10.12    Assignment

         With DTS's permission, which permission shall not be unreasonably
withheld, this Agreement, the Convertible Debentures and the DTS Shares may be
endorsed, assigned and/or transferred in whole or in part by Wi-LAN, and any
such holder and/or assignee of the same shall succeed to and be possessed of the
rights and powers of Wi-LAN under all of the same to the extent transferred and
assigned. DTS shall not assign any of its rights nor delegate any of its duties
under this Agreement or any documents delivered pursuant hereto by operation of
law or otherwise without the prior express written consent of Wi-LAN, which may
be withheld in Wi-LAN's sole and unfettered discretion, and if DTS obtains such
consent, this Agreement and the other documents delivered pursuant hereto shall
be binding upon such assignee.

<PAGE>

                                       13

10.13    Reliance

         The parties hereto acknowledge and agree that they have entered into
this Agreement in reliance upon each of the representations, warranties,
covenants and agreements herein of the other party hereto.

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

                                   WI-LAN INC.

                                   Per: /s/ Hatim Zaghloul
                                        ----------------------------------
                                        Hatim Zaghloul
                                        Chairman and Chief Executive Officer

                                   DIGITAL TRANSMISSION SYSTEMS, INC.

                                   Per: /s/ Andres C. Salazar
                                        ----------------------------------
                                        Andres C. Salazar
                                        Chief Executive Officer

<PAGE>

                                  SCHEDULE "A"
                      REPRESENTATIONS AND WARRANTIES OF DTS

         DTS represents and warrants to Wi-LAN that:

1.1      Corporate Existence and Power

         DTS is a corporation duly incorporated, validly existing and in good
standing under the laws of the State of Delaware, and has all requisite
corporate power and authority to own, lease and operate its properties and to
carry on its business substantially as now conducted, except where the failure
to do so would not have, individually or in the aggregate, a DTS Material
Adverse Effect. DTS is duly qualified to do business as a foreign corporation
and is in good standing in each jurisdiction where the character of the property
owned or leased by it or the nature of its activities makes such qualification
necessary, except for those jurisdictions where the failure to be so qualified
would not have, individually or in the aggregate, a DTS Material Adverse Effect.

1.2      Corporate Authorization

         The execution, delivery and performance by DTS of this Agreement and
the consummation of the transactions contemplated hereby by DTS are within DTS's
corporate power and authority and, have been duly authorized by all necessary
corporate action on the part of DTS. This Agreement has been duly executed and
delivered by DTS and constitutes a legal, valid and binding agreement of DTS.

1.3      Governmental Authorization

         The execution, delivery and performance by DTS of this Agreement and
the consummation of the transactions contemplated hereby by DTS do not require
any consent, approval, authorization or permit of or other action by, or filing
with, any governmental body, agency, official or authority.

1.4      Non-Contravention

         The execution, delivery and performance by DTS of this Agreement and
the consummation of the transactions contemplated hereby by DTS and the
execution, delivery and performance by MicroTel and Finova of the Related
Agreements and the consummation of the transactions contemplated thereby by
MicroTel and Finova do not and will not (i) contravene or conflict with the
Certificate of Incorporation or By-Laws of DTS, (ii) contravene or conflict with
or constitute a violation of any provision of any law, rule, regulation,
judgment, injunction, order or decree binding upon or applicable to DTS or any
of its Subsidiaries, (iii) constitute a default under or give rise to a right of
termination, cancellation or acceleration of any right or obligation or to the
loss of any benefit or material adverse modification of the effect (including an
increase in the price paid by, or cost to, DTS or any of its Subsidiaries) of,
or under any provision of any agreement or other instrument to which DTS is a
party or that is binding upon DTS or any of its Subsidiaries or their properties
or assets or any license, franchise, permit or other similar authorization held
by DTS or any of its Subsidiaries, or (iv) result in the creation or imposition
of any Lien on any asset of DTS or any of its Subsidiaries, except for any
occurrences or results referred to in clauses (ii), (iii), and (iv) that would
not have, individually or in the aggregate, a DTS Material Adverse Effect or
prevent or delay consummation of the transactions contemplated hereby or by the
Related Agreements.

1.5      Capitalization

(a)      The authorized capital stock of DTS consists of (i) 15,000,000 shares
         of Common Stock, of which, as of the date hereof, (A) 4,646,221 shares
         were issued and outstanding, (B) 1,019,880 shares were reserved for
         issuance upon exercise of options issued pursuant to DTS stock option
         plans, (C) 1,314,333 shares were reserved for issuance upon exercise of
         1,314,333 outstanding preferred shares, (D) 2,433,315 shares were
         reserved for issuance upon exercise of outstanding warrants and

<PAGE>

                                        2

         (E) 2,000,000 shares were reserved for issuance upon conversion of a
         U.S.$2,000,000 convertible debenture held by Finova, and (ii) 3,000,000
         shares of preferred stock, of which at the date hereof 1,314,333 shares
         were issued and outstanding. Except as described in this section 1.5,
         as of the date of this Agreement, no shares of capital stock of DTS are
         reserved for issuance for any purpose. Each of the issued shares of
         capital stock of DTS is duly authorized, validly issued and fully paid
         and nonassessable, and has not been issued in violation of (nor are any
         of the authorized shares of capital stock subject to) any preemptive or
         similar rights created by statute, the Certificate of Incorporation or
         Bylaws of DTS, or any agreement to which DTS is a party or is bound.

(b)      Except as set forth in paragraph (a) above, there are no options,
         warrants or other rights, agreements, arrangements or commitments of
         any character to which DTS is a party relating to the issued or
         unissued capital stock of DTS or obligating DTS to grant, issue or sell
         any shares of the capital stock of DTS. There are no obligations,
         contingent or otherwise, of DTS to (i) repurchase, redeem or otherwise
         acquire any shares of its capital stock, or the capital stock or other
         equity interests of any Subsidiary of DTS; or (ii) (other than advances
         to Subsidiaries in the ordinary course of business) provide material
         funds to, or make any material investment in (in the form of a loan,
         capital contribution or otherwise), or provide any guarantee with
         respect to the obligations of, any Subsidiary of DTS or any other
         person. There are no outstanding stock appreciation rights or similar
         derivative securities or rights of DTS or any of its Subsidiaries.
         There are no bonds, debentures, notes or other indebtedness of DTS
         having the right, to vote (or convertible into, or exchangeable for,
         securities having the right to vote) on any matters on which
         stockholders of DTS may vote.

(c)      DTS has delivered to Wi-LAN complete and correct copies of all DTS
         stock option plans and all forms of options issued pursuant to DTS
         stock option plans, including all amendments thereto.

1.6      Subsidiaries

         DTS does not have any Subsidiaries. Other than LinkaNet Labs, Inc., of
which DTS owns 19.5% of the outstanding shares, DTS does not directly or
indirectly own any equity or similar interest in, or any interest convertible
into or exchangeable or exercisable for any equity or similar interest in, any
corporation, partnership, joint venture or other business association or entity.

1.7      Reports

         Since December 31, 1998, DTS and its Subsidiaries have timely filed (i)
all forms, reports, statements and other documents required to be filed with (A)
the SEC, including without limitation (1) all Annual Reports on Form 10-KSB, (2)
all Quarterly Reports on Form 10-Q, (3) all proxy statements relating to
meetings of stockholders (whether annual or special), (4) all Current Reports on
Form 8-K and (5) all other reports, schedules, registration statements or other
documents (collectively referred to as the "DTS SEC Reports"), and (B) any other
applicable state securities authorities and (ii) all forms, reports, statements
and other documents required to be filed with any other applicable federal or
state regulatory authorities, except where the failure to file any such forms,
reports, statements or other documents would not have a DTS Material Adverse
Effect (all such forms, reports, statements and other documents in clauses (i)
and (ii) of this Section 1.7 being referred to herein, collectively, as the "DTS
Reports"). DTS Reports (i) have been made available to Wi-LAN, (ii) were
prepared in all material respects in accordance with the requirements of
applicable law (including, with respect to DTS SEC Reports, the Securities Act
of 1933 and the rules and regulations promulgated thereunder (the "Securities
Act") or the Exchange Act, as the case may be) and (iii) did not at the time
they were filed contain any untrue statement of a material fact or omit to state
a material fact required to be stated therein or necessary in order to make the
statements therein, in the light of the circumstances under which they were
made, not misleading.

<PAGE>

                                        3

1.8      Financial Statements

         The audited consolidated financial statements and unaudited
consolidated interim financial statements of DTS and its consolidated
Subsidiaries included in DTS SEC Reports, including reports on Forms 10-K and
10-Q, comply as to form in all material respects with applicable accounting
requirements and the published rules and regulations of the SEC with respect
thereto, were prepared in accordance with generally accepted accounting
principles applied on a consistent basis (except as may be indicated in the
notes thereto), and fairly present the consolidated financial position of DTS
and its consolidated Subsidiaries as of the dates thereof and their consolidated
results of operations and cash flows for the periods then ended (subject, in the
case of any unaudited interim financial statements, to normal year-end
adjustments, none of which would have, individually or in the aggregate, a DTS
Material Adverse Effect).

1.9      Absence of Certain Changes

         Since December 31, 1998 (a) except as described in any DTS SEC Report,
DTS and its Subsidiaries have conducted their business in all material respects
in the ordinary course consistent with past practices, (b) except as described
in any DTS SEC Report, there has not been any event or events having,
individually or in the aggregate, a DTS Material Adverse Effect, (c) there has
not been any declaration, setting aside or payment of any dividend or other
distribution with respect to any shares of capital stock of DTS, or any
repurchase, redemption or other acquisition by DTS or any of its Subsidiaries of
any outstanding shares of capital stock or other securities of, or other
ownership interests in, DTS or any of its Subsidiaries or any split, combination
or reclassification of any of any of DTS's capital stock or issuance or
authorization relating to the issuance of any other securities in respect of, in
lieu of or in substitution for shares of DTS's capital stock, (d) there has not
been any amendment of any material term of any outstanding security of DTS or
any of its Subsidiaries, (e) except as reflected in DTS's SEC Reports, there has
not been any incurrence, assumption or guarantee by DTS or any of its
Subsidiaries, of any indebtedness for borrowed money or any other agreement or
arrangement entered into by DTS or any of its Subsidiaries having the economic
effect of any of the foregoing, except (i) accounts payable of DTS or any of its
Subsidiaries incurred in the ordinary course of business consistent with past
practice or (ii) pursuant to loan and other financing agreements disclosed in
the DTS SEC Reports; (f) there has not been any creation or assumption by DTS or
any of its Subsidiaries of any Lien on any material asset other than in the
ordinary course of business consistent with past practices (including the sale,
pledging or assignment of receivables) except in connection with indebtedness
referred to in clause (e); (g) there has not been any change in any method of
accounting or accounting practice by DTS or any of its Subsidiaries, except for
any such change required by reason of a concurrent change in generally accepted
accounting principles or to conform a Subsidiary's accounting policies and
practices to those of DTS; (h) except as disclosed in any DTS SEC Report, there
has not been any (i) grant of any severance or termination pay to any director,
executive officer or key employee of DTS or any of its Subsidiaries, (ii)
entering into of any employment, deferred compensation or other similar
agreement (or any amendment to any such existing agreement) with any director,
executive officer or key employee of DTS or any of its Subsidiaries, (iii)
increase in benefits payable under any existing severance or termination pay
policies or employment agreements with any director, executive officer or key
employee, or (iv) increase in compensation, bonus or other benefits payable to
directors, executive, officers or key employees of DTS or any of its
Subsidiaries; (i) there has not been any sale or transfer by DTS of any of the
assets of DTS (other than sales or transfers of immaterial assets in the
ordinary course of business), cancellation of any material debts or claims or
waiver of any material rights by DTS; (j) there has not been any amendment to
DTS's Certificate of Incorporation or Bylaws; (k) DTS has not made any loans,
advances or capital contributions to or investments in, any other person, other
than to any direct or indirect wholly-owned Subsidiary of DTS and other than
travel and entertainment advances to employees of DTS in the ordinary course of
business consistent with past practices; (l) except for this Agreement and any
other agreement executed and delivered pursuant to this Agreement, DTS has not
entered into any material transaction or incurred any material expenditure other
than in the ordinary course of business or permitted under other sections of
this Agreement or in connection with the transactions contemplated hereby; and
(m) there have not been any payments or other distributions by DTS or any of its
Subsidiaries or any of its officers, directors or affiliates, except for
compensation for service as a director or officer as disclosed in DTS SEC
Reports.

<PAGE>

                                        4

1.10     Litigation

         Except as described in any DTS SEC Report, there is no action, suit,
investigation or proceeding pending or, to the best of DTS's knowledge,
threatened against DTS or any of its Subsidiaries or to which any of their
respective properties, assets or rights are reasonably likely to be subject
before any court or arbitrator or any governmental body, agency or official
which would reasonably be expected to have, individually or in the aggregate, a
DTS Material Adverse Effect, nor is there any judgment, decree, injunction, rule
or order of any court or arbitrator or any governmental body, agency or official
outstanding against DTS or any of its Subsidiaries which would have,
individually or in the aggregate, a DTS Material Adverse Effect.

1.11     Certificate of Incorporation and Bylaws

         DTS has heretofore furnished to Wi-LAN complete and correct copies of
the Certificates of Incorporation and the Bylaws or the equivalent
organizational documents, in each case as amended or restated, of DTS and each
of its Subsidiaries.

1.12     ERISA

(a)      "Employee Plans" shall mean each "employee benefit plan," as defined in
         Section 3(3) of the Employee Retirement Income Security Act of 1974
         ("ERISA"), which (i) is subject to any provision of ERISA and (ii) is
         maintained, administered or contributed to by DTS or any affiliate (as
         defined below) and covers any employee or former employee of DTS or any
         affiliate or under which DTS or any affiliate has any liability. For
         purposes of this Section and Section 4.13, "affiliate" of any person
         means any other person which, together with such person, would be
         treated as a single employer under Section 414 of the Internal Revenue
         Code of 1986, as amended (the "Code").

(b)      No Employee Plan constitutes a "multiemployer plan," as defined in
         Section 3(37) of ERISA, and no Employee Plan is subject to Title IV of
         ERISA. Neither DTS nor any of its affiliates has incurred, nor are they
         reasonably likely to incur, any liability under Title IV of ERISA
         arising in connection with the termination of, or complete or partial
         withdrawal from, any plan previously covered by Title IV of ERISA that
         would have, individually or in the aggregate, a DTS Material Adverse
         Effect. No transaction or holding of any asset under or in connection
         with any Employee Plan has or will make DTS or any of its Subsidiaries
         or any officer or director of DTS or any of its Subsidiaries subject to
         any liability under Section 502(i) of ERISA or liable for any tax
         pursuant to Section 4975 of the Code that would have, individually or
         in the aggregate, a DTS Material Adverse Effect.

(c)      Except to the extent it would not have, individually or in the
         aggregate, a DTS Material Adverse Effect, (i) each Employee Plan that
         is intended to be qualified under Section 401(a) of the Code is the
         subject of a favorable determination letter issued by the Internal
         Revenue Service relating to its qualified status, and, to DTS's
         knowledge, nothing has occurred that would adversely effect the
         qualified status of any such plan, and (ii) each Employee Plan has been
         maintained in compliance with its terms and with the requirements
         prescribed by any and all statutes, orders, final rules and final
         regulations, including but not limited to ERISA and the Code, which are
         applicable to such Employee Plan.

(d)      "Benefit Arrangement" shall mean each employment, severance or other
         similar contract, arrangement or policy and each plan or arrangement
         (written or oral) providing for compensation, bonus, profit-sharing,
         stock option, or other stock related rights or other forms of incentive
         or deferred compensation, which (i) is not an Employee Plan, (ii) is
         entered into, maintained or contributed to, as the case may be, by DTS
         or any of its affiliates, and (iii) covers any employee or former
         employee of DTS or any of its affiliates. Except to the extent that it
         would not have, individually or in the aggregate, a DTS Material
         Adverse Effect, each Benefit Arrangement has been maintained in
         compliance with its terms and with the requirements prescribed by any
         and all statutes, orders, rules and regulations that are applicable to
         such Benefit Arrangement.

<PAGE>

                                        5

(e)      With respect to each Employee Plan and Benefit Arrangement (where
         applicable): DTS has made available to Wi-LAN complete and accurate
         copies of the following: (i) all plan texts and agreements; (ii) all
         material employee communications (including summary plan descriptions);
         (iii) the most recent annual report; (iv) the most recent annual and
         periodic accounting of plan assets; (v) the most recent determination
         letter received from the IRS; and (vi) the most recent actuarial
         valuation.

(f)      The consummation of the transactions contemplated by this Agreement and
         the Related Agreements will not (i) entitle any individual to severance
         pay, (ii) accelerate the time of payment or vesting of, or increase the
         amount of, compensation due to any individual or (iii) result in the
         payment of an amount that will be taken into account in determining
         whether there is an "excess parachute payment" under Section 280G(b)(l)
         of the Code.

1.13     Taxes

         Except for such matters that would not have, individually or in the
aggregate, a DTS Material Adverse Effect, (a) DTS and its Subsidiaries have
timely filed all returns and reports required to be filed by them with any
taxing authority with respect to taxes, taking into account any extension of
time to file granted to or obtained on behalf of DTS and its Subsidiaries, (b)
all taxes required to be paid with respect to the periods covered by such
returns or reports that are due prior to the Related Agreement Closing Date have
been paid or will be paid prior to the Related Agreement Closing Date, (c) no
deficiency for any material amount of tax has been asserted or assessed by a
taxing authority against DTS or any of its Subsidiaries and remains unpaid, (d)
all liability for taxes of DTS or any of its Subsidiaries that are or will
become due or payable with respect to periods covered by the financial
statements referred to in section 1.8 have been paid or adequately reserved for
on such financial statements in accordance with generally accepted accounting
principles and (e) DTS and its Subsidiaries have withheld and paid all taxes
required to have been withheld or paid in connection with amounts paid to any
employee, independent contractor, creditor, stockholder or other third party.

1.14     Finders and Investment Bankers

         There is no investment banker, broker, finder or other intermediary
which has been retained by or is authorized to act on behalf of DTS or any of
its Subsidiaries who might be entitled to any fee or commission in connection
with the transactions contemplated by this Agreement or the Related Agreements.
Neither DTS nor any of its Subsidiaries has entered into any contract,
arrangement or understanding to pay any fee or commission to any investment
banker, broker, finder or other intermediary on behalf of any significant
stockholders of DTS including, without limitation Finova or MicroTel, in
connection with the transactions contemplated by this Agreement or the Related
Agreements.

1.15     Anti-takeover Plan; State Takeover Statutes

         Neither DTS nor any Subsidiary has in effect any plan, scheme, device
or arrangement, commonly or colloquially known as a "poison pill" or
"anti-takeover" plan or any similar plan, scheme, device or arrangement. The
Board of Directors of DTS has approved the Related Agreements and this Agreement
and the transactions contemplated thereby and hereby. Such approval is
sufficient to render inapplicable to the Related Agreements and this Agreement
and the transactions contemplated by this Agreement and the Related Agreements
the provisions of Section 203 of Delaware Law. To the best of DTS's knowledge,
no other state takeover statute or similar statute or regulation applies or
purports to apply to the Related Agreements, this Agreement, or any of the
transactions contemplated by this Agreement or the Related Agreements.

<PAGE>

                                        6

1.16     Environmental Matters

         Except as set forth in DTS SEC Reports (including the notes to the
financial statements attached thereto), to the knowledge of DTS, (A) DTS and
each of its Subsidiaries has obtained and is in material compliance with the
terms and conditions of all permits, licenses and other authorizations required
under applicable Environmental Laws; (B) DTS and each of its Subsidiaries is in
material compliance with all applicable Environmental Laws; (C) none of DTS or
any of its Subsidiaries has received written notice of any past or present
events, conditions, circumstances, activities, practices or incidents that have
resulted in or threatened to result in any common law or legal liability of DTS
or, any Subsidiary or otherwise form the basis of any claim, action, suit or
proceeding, hearing or investigation against DTS or any Subsidiary under any
Environmental Laws; and (D) DTS has no liabilities and there are no
circumstances or events related to DTS or its properties, assets or business
that are reasonably likely to result in any such liability under any
Environmental Laws, except to the extent that any of the matters addressed in
clauses (A) through (D) above would not, individually or in the aggregate,
constitute a DTS Material Adverse Effect. As used herein, "Environmental Laws"
means all federal, state and local statutes, regulations and ordinances
concerning pollution and protection of the environment, including, without
limitation all those relating to the presence, use, production, distribution,
labeling, testing, processing, discharge, release, threatened release, control,
or cleanup of any hazardous materials, substances or wastes, as such statutes,
regulations and ordinances are enacted and in effect at or prior to the Related
Agreement Closing Date. DTS has made available to Wi-LAN true, complete and
correct copies of all environmental reports in its possession relating to DTS or
its properties or assets.

1.17     Title to Properties; Absence of Liens and Encumbrances; Leases;
         Condition of Facilities

(a)      Except as set forth in DTS SEC Reports, DTS and its Subsidiaries have
         good and insurable title to all of their real properties and interests
         in real properties (fee simple title as to real properties owned by DTS
         or its Subsidiaries) and good title to all their other properties and
         assets, tangible and intangible, including all of the buildings,
         structures and other improvements located on such real properties, free
         and clear of all claims, encumbrances and other title defects other
         than (i) as specifically disclosed in the consolidated balance sheet of
         DTS at September 30, 1999, (ii) any liens for taxes not yet due and
         payable or being contested in good faith by appropriate proceedings for
         which adequate reserves have been provided in the consolidated balance
         sheet of DTS at September 30, 1999, and (iii) such imperfections of
         title, covenants, restrictions, easements and other non-monetary
         encumbrances, if any, as do not, individually or in the aggregate,
         materially detract from the value or materially interfere with the
         present use of any of the properties of DTS or any of its Subsidiaries
         or otherwise would not have, individually or in the aggregate, a DTS
         Material Adverse Effect.

(b)      The leases pursuant to which DTS or any of its Subsidiaries leases any
         real or personal property are (i) valid and binding on DTS or the
         applicable Subsidiary and (ii), to the knowledge of DTS, valid and
         binding on all other respective parties to such leases in accordance
         with their respective terms. There are not under such leases any
         existing breaches, defaults, events of default by DTS or a Subsidiary
         or events which with notice and/or lapse of time would constitute a
         breach, default or event of default by DTS or a Subsidiary, nor does
         DTS know, nor has DTS received notice of, or made a claim with respect
         to, any breach or default, the consequences of which would have,
         individually or in the aggregate, a material adverse effect on the
         aggregate value of the properties of DTS and its Subsidiaries or a DTS
         Material Adverse Effect. None of the rights of DTS or its Subsidiaries
         under any such leases is subject to termination or modification as a
         result of the transactions contemplated hereby, except where such
         modification or termination would not have, individually or in the
         aggregate, a DTS Material Adverse Effect. DTS has provided Wi-LAN with
         true, correct and complete copies of all of the leases, subleases,
         licenses, overleases and other similar agreements (including all
         modifications, amendments and supplements thereto) with respect to real
         property leased by DTS or its Subsidiaries.

<PAGE>

                                        7

(c)      To the knowledge of DTS, each of the facilities owned, leased or
         managed by DTS or its Subsidiaries (each such facility, a "Facility")
         is in all material respects suitable for its current and intended use
         and is in all material respects in proper condition for such use.

1.18     Compliance with Laws; Government Approvals

         The business of DTS and its Subsidiaries has been operated in
compliance with all laws, ordinances, regulations and orders of all governmental
entities, except for violations which would not have, individually or in the
aggregate, a DTS Material Adverse Effect. DTS and its Subsidiaries have all
permits, certificates, licenses, approvals, consents and other authorizations of
all governmental agencies (collectively, "Government Approvals"), whether
Federal, state or local, required by law with respect to the operation of their
businesses, except those the absence of which would not have, individually or in
the aggregate, a DTS Material Adverse Effect or prevent or delay consummation of
the transactions contemplated hereby . All such Government Approvals are in full
force and effect, and DTS and its Subsidiaries are in compliance in all material
respects with all conditions and requirements of the Government Approvals and
with all rules and regulations relating thereto. DTS has not received any
notices of violations of any Federal, state and local laws, regulations and
ordinances relating to its business and operations, including the Occupational
Safety and Health Act, the Americans with Disabilities Act, any applicable
Medicare or Medicaid, statutes and regulations, and any applicable law for
reimbursement for assisted living care or other type of care provided at each
Facility, license, certificate of need, ordinance, or governmental or regulatory
rule or regulation, whether Federal, state, local or foreign, to which DTS's
business, operations, assets or properties is subject and no notice of any
pending inspection of or violation of any such law, regulation or ordinance has
been received by DTS which, in the case of any of the foregoing, if it were
determined that a violation had occurred, would have a DTS Material Adverse
Effect.

1.19     Undisclosed Liabilities

         Except as and to the extent reflected, reserved against or otherwise
disclosed in DTS's consolidated balance sheet at September 30, 1999 (including
the notes thereto), neither DTS nor any of its Subsidiaries had, at September
30, 1999, any liabilities or obligations of any kind, whether accrued, absolute,
asserted or unasserted, contingent or otherwise, whether or not such liabilities
would have been required to be disclosed on a balance sheet prepared in
accordance with generally accepted accounting principles consistently applied,
which would have, individually or in the aggregate, a DTS Material Adverse
Effect.

1.20     Insurance

         DTS maintains, and has maintained, without interruption, during its
existence, policies or binders of insurance covering such risk, and events,
including personal injury, property damage and general liability in amounts DTS
reasonably believes adequate for its business and operations and such policies
shall not terminate as a result of the consummation of the transactions
contemplated hereby or by the Related Agreements.

1.21     Absence of Sensitive Payments

         To DTS's knowledge, none of DTS, or any Subsidiary or affiliate or any
officer or director of any of them acting alone or together, has performed any
of the following acts, except to the extent that such acts, individually or
collectively, would not have a DTS Material Adverse Effect: (i) the making of
any contribution, payment, remuneration, gift or other form of economic benefit
(a "Payment") to or for the private use of any governmental official, employee
or agent where the Payment or the purpose of the Payment was illegal under the
laws of the United States or the jurisdiction in which such payment wag made,
(ii) the establishment or maintenance of any unrecorded fund, asset or liability
for any purpose or the making of any false or artificial entries on its books,
(iii) the making of any Payment to any person or the receipt of any Payment with
the intention or understanding that any part of the Payment was to be used for
any purpose other than that described in the documents supporting the Payment,
or (iv) the giving of any Payment to, or

<PAGE>

                                        8

the receipt of any Payment from, any person who was or could have been in a
position to help or hinder the business of DTS or any Subsidiary (or assist DTS
or any Subsidiary in connection with any actual or proposed transaction) which
(A) would reasonably have been expected to subject DTS or any Subsidiary to any
damage or penalty in any civil, criminal or governmental litigation or
proceeding, (B) if not given in the past, would have had a DTS Material Adverse
Effect or (C) if it had not continued in the future, would have had a DTS
Material Adverse Effect.

1.22     Affiliate Transactions

         Except to the extent disclosed in any DTS SEC Report, there are no
transactions, agreements, arrangements or understandings between DTS or its
Subsidiaries, on the one hand, and DTS's officers or directors, MicroTel, Finova
or any officer or director of MicroTel or Finova, any spouse or child of any
such person, or any Affiliates (other than wholly-owned Subsidiaries of DTS) nor
is DTS or any other Subsidiary indebted, directly or indirectly, to any of such
persons, or to their respective spouses or children, nor are any of such persons
indebted to DTS or any Subsidiary. None of such persons have any direct or
indirect ownership interest in any firm or corporation with which DTS or any
Subsidiary is affiliated or which DTS or a Subsidiary has a business
relationship. Neither DTS nor any Subsidiary is a guarantor or indemnitor of any
indebtedness of any other person. For purposes of this Agreement, the term
"Affiliate," when used with respect to any person, means any other person
directly or indirectly controlling, controlled by, or under common control with
such person. As used in the definition of "Affiliate," the term "control" means
possession, directly or indirectly, of the power to direct or cause the
direction of the management or policies of a person, whether through the
ownership of voting securities, by contract or otherwise.

1.23     Contracts

         There is no contract, agreement or understanding required to be
described in or filed as an exhibit to any DTS SEC Report that is not described
in or filed as required by the Securities Act or the Exchange Act, as the case
may be. Except as would not individually or in the aggregate have a DTS Material
Adverse Effect, all such contracts, agreements and understandings are valid and
binding and are in full force and effect and enforceable in accordance with
their respective terms other than contracts, agreements or understandings which
are by their terms no longer in force or effect. No approval or consent of, or
notice to, any person is needed in order that such contract, agreement or
understanding shall continue in full force and effect in accordance with its
terms without penalty, acceleration or rights of early termination following the
consummation of the transactions contemplated by this Agreement and the Related
Agreements. Except to the extent any of the following would not individually or
in the aggregate have a DTS Material Adverse Effect, DTS is not in violation or
breach of or default under any such contract, agreement or understanding, nor to
DTS's knowledge is any other party to any such contract, agreement or
understanding. Except as set forth in DTS SEC Reports, DTS is not a party to any
contracts, agreements or arrangements (including leases of real property) (i)
restricting the ability of DTS or any of its Subsidiaries to compete or engage
in business or guarantees of indebtedness of any person (other than a
Subsidiary) or (ii) with MicroTel or Finova or any of its officers, directors or
affiliates which are not terminable by DTS without penalty on no more than
30-days' written notice. Neither MicroTel nor Finova or their respective
affiliates provide any services or benefits to DTS and its Subsidiaries the
absence of which individually or in the aggregate would have a DTS Material
Adverse Effect.

1.24     Intellectual Property

(a)      Except for items that would not constitute a DTS Material Adverse
         Effect, to DTS's knowledge, the Company is the lawful owner or has a
         valid right to use the proprietary information used in its business
         including, without limitation, free and clear of any claim, right,
         trademark, patent or copyright protection of any third party; provided,
         however, that this paragraph (a) shall not be deemed to include any
         representation regarding the absence of infringements or conflicts with
         the rights of others, which representation is made only in paragraph
         (c) hereof. As used herein,"proprietary information" includes without
         limitation (i) any computer software and any documentation, inventions,
         and technical and

<PAGE>

                                        9

         nontechnical data related thereto, and (ii) other documentation,
         inventions and data related to patterns, plans, methods, techniques,
         drawings, finances, customer lists, suppliers, products, special
         pricing and cost information, designs, processes, procedures, formulas,
         research data owned or used by DTS or any Subsidiary or marketing
         studies conducted by DTS all of which DTS considers to be commercially
         important and competitively sensitive and which generally has not been
         disclosed to third parties other than customers in the ordinary course
         of business.

(b)      To DTS's knowledge, DTS has good and marketable title to or has a valid
         right to use all patents, trademarks, trade names, service marks,
         copyrights or other intangible property rights, and registrations or
         applications for registration thereof, owned by DTS or any Subsidiary
         or used or required by DTS or any Subsidiary in the operation of its
         business as presently being conducted including, without limitation,
         the trademarks set forth in Schedule "B" hereto; provided, however,
         that this paragraph (b) shall not be deemed to include any
         representation regarding the absence of infringements or conflicts with
         the rights of others, which representation is made only in paragraph
         (c) hereof.

(c)      DTS has no knowledge of any infringements or conflicts with asserted
         rights of others with respect to copyrights, patents, trademarks,
         service marks, trade names, trade secrets or other intangible property
         rights or know-how which could cause a DTS Material Adverse Effect. To
         DTS's knowledge, no products or processes of DTS infringe or conflict
         with any rights of patent or copyright, or any discovery, invention,
         product or process, that is the subject of a patent or copyright
         application or registration known to DTS. DTS follows such procedures
         as DTS deems necessary or appropriate to provide reasonable protection
         of DTS's trade secrets and proprietary rights in intellectual property
         of all kinds. To the knowledge of DTS, no person employed by or
         affiliated with DTS has employed or proposes to employ any trade secret
         or any information or documentation proprietary to any former employer,
         and to the knowledge of DTS, no person employed by or affiliated with
         DTS has violated any confidential relationship that such person may
         have had with any third person, in connection with the development,
         manufacture or sale of any product or proposed product or the
         development or sale of any service or proposed service of DTS.

1.25     Limited Offering

         The offer, sale and issuance of the Convertible Debentures and DTS
Shares is exempt from the registration requirements of the Securities Act, and
neither DTS nor any authorized agent acting on its behalf has taken or will take
any action hereafter that would cause the loss of such exemption.

1.26     Registration Obligations

         DTS is not under any obligation to register under the Securities Act or
the Trust Indenture Act of 1939, as amended, any of its presently outstanding
securities or any of its securities that are proposed to be subsequently issued.

1.27     Accounting Matters

         DTS and each of its Subsidiaries maintain a system of internal
accounting controls sufficient to provide reasonable assurance that (i)
transactions are executed in accordance with management's general or specific
authorization; (ii) transactions are recorded as necessary to permit preparation
of financial statements in conformity with generally accepted accounting
principles and to maintain accountability for the assets of DTS and each of its
Subsidiaries; (iii) access to the assets of DTS and each of its Subsidiaries is
permitted only in accordance with management's general or specific
authorization; and (iv) the recorded accountability for assets of DTS and each
of its Subsidiaries are compared with the existing assets at reasonable
intervals and appropriate action is taken with respect to any differences.

<PAGE>

                                       10

1.28     Prior Sales

         All offers and sales of DTS's capital stock prior to the date hereof
were at all relevant times (i) exempt from the registration requirements of the
Securities Act or were duly registered under the Securities Act, and (ii) were
duly registered or were the subject of an available exemption from the
registration requirements of all applicable state securities or Blue Sky laws.

1.29     Hart-Scott-Rodino Representation

         As of the date hereof and as of the Closing Date, the annual net sales
and total assets of DTS, as determined in accordance with the regulations
promulgated under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, are
less than U.S.$25,000,000.

1.30     DTS Securities Acquired by Wi-LAN

(a)      The DTS Shares acquired by Wi-LAN pursuant to the Related Agreements
         are listed on the Nasdaq Over-The-Counter Market.

(b)      The DTS Shares issuable upon conversion of the DTS securities acquired
         by Wi-LAN pursuant to the Related Agreements have been authorized for
         listing, subject to official notice of issuance, on the Nasdaq
         Over-The-Counter Market.

(c)      Other than unregistered securities trading restrictions under federal
         and state laws of the United States and the U.S.$2,000,000 convertible
         debenture which Wi-LAN is acquiring from Finova which may not be
         transferred to a "competitor" of DTS without DTS's consent, the DTS
         Shares and the DTS securities which Wi-LAN is acquiring pursuant to the
         Related Agreements are transferrable, are freely exercisable by Wi-LAN
         and no third party consent is required in connection with any such
         exercise.

<PAGE>

                                  SCHEDULE "B"
                   LIST OF INTELLECTUAL PROPERTY OWNED BY DTS

<PAGE>

                                  SCHEDULE "C"
                                 PROMISSORY NOTE

U.S.$400,000                                             Date: December 29, 1999

FOR VALUE RECEIVED, the undersigned, DIGITAL TRANSMISSION SYSTEMS, INC.,
("DTS"), a Delaware corporation, (the "Maker") promises to pay to the order of
WI-LAN, INC., ("Wi-LAN") an Alberta, Canada corporation, its successors and
assigns (the "Lender" or "Holder") with its principal place of business in
Calgary, Alberta, Canada, or elsewhere as directed from time to time in writing
by the Holder hereof, the principal sum of Four Hundred Thousand dollars
($400,000), together with interest thereon at the rate of ten percent (10%) per
annum, in lawful money of the United States of America, payable as follows:

Interest shall accrue from the period of December 29, 1999, until such time as
the entire principal sum herein is repaid in full, on the principal amount at an
annual rate of Ten Percent (10%); and a one-time payment of U.S.$400,000 and
accumulated interest due and payable on the closing date of the sale by DTS to
Wi-LAN of a U.S.$1,500,000 convertible debenture pursuant to that certain
convertible debenture purchase agreement executed by DTS and Wi-LAN on even date
herewith; and, should the Related Agreement Closing Date (as defined in the said
convertible debenture purchase agreement) not have occurred on or before January
31, 2000, the loan amount of U.S.$50,000 will be forgiven by the Holder and the
remaining principal amount of U.S.$350,000 will be payable in consecutive,
monthly installments of U.S.$17,500, commencing March 1, 2000 and continuing on
the first day of each successive month thereafter until the principal sum of
U.S.$350,000 and interest is paid in full.

Payment not received within five (5) days of the due date shall be deemed a
default under this Note. If the undersigned defaults in the payment hereunder,
the Note shall bear interest at the annual rate of 15% ("default rate") on the
amount then due and payable. Upon default for non-payment of the Note, the
entire principal balance of this obligation, together with accrued interest,
shall, at the Holder's election, become immediately due and payable.

As set forth in the convertible debenture purchase agreement executed by DTS and
Wi-LAN on even date herewith, Holder shall have the option to convert the
principal amount of the Note and any accrued interest on the Note into an
equivalent principal amount of Convertible Debentures (as defined in the said
convertible debenture purchase agreement) if the Related Agreement Closing Date
(as defined in the said convertible debenture purchase agreement) shall not have
occurred on or before January 31, 2000.

Maker shall provide Holder with copies of Maker's financial statements,
including balance sheets, income statements and cash flow projections, prepared
on a monthly basis, on or before the fifteenth (15th) of each month. Failure to
provide said financial statements may constitute a default under this Note, at
the sole discretion of Holder.

As security for the amount due herein, the Maker pledges as collateral, all of
the assets ("Assets") set forth in that certain security agreement executed by
the Maker and Holder on even date herewith. The rights or remedies of the Holder
as provided in this Note and said security agreement shall be cumulative and
concurrent, and may be pursued singularly, successively, or together against the
property described in the security agreement. The failure to exercise any such
right or remedy shall in no event be construed as a waiver or release of such
rights or remedies or the right to exercise them at any later time.

Maker shall have the privilege to prepay the indebtedness evidenced hereby, in
whole or in part at any time after February 15, 2000. Partial prepayments shall
first be applied against accrued interest then due and owing, and thereafter
against principal. Any partial prepayment shall not postpone the due date or
change the amount of any subsequent payment.

All persons or entities now or at anytime liable for payment of this Note hereby
waive presentment, protest, notice of protest and dishonor. The Maker and all
persons/entities liable hereunder expressly consent to any

<PAGE>

                                        2

extensions or renewals, in whole or in part, and all delays in timely payment or
other performance which Holder may grant at any time and from time to time
without limitation and without any notice or further consent of the undersigned.

In the event this Note is placed in the hands of an attorney for collection by
civil action the prevailing party shall be entitled to an award of its
attorneys' fees and costs, including those on appeal.

This Note is to be construed and enforced according to the laws of the State of
Georgia or, if Holder elects the benefit thereof, applicable Federal pre-emption
laws. The venue for instigation of a lawsuit to collect any sum due herein shall
be Gwinnett County, Georgia.

                                   DIGITAL TRANSMISSION SYSTEMS, INC.

                                   Per:
                                        ----------------------------------
                                        Andres C. Salazar
                                        Chief Executive Officer

<PAGE>

                                        3

                               SECURITY AGREEMENT

THIS SECURITY AGREEMENT ("Agreement") is made this 29th of December, 1999, by
and between DIGITAL TRANSMISSION SYSTEMS, INC., ("DTS"), a Delaware corporation,
(the "Debtor"), and WI-LAN, INC., ("Wi-LAN") an Alberta, Canada corporation (the
"Secured Party"), collectively referred to as the "parties", who agree as
follows:

Debt and Collateral. The Debtor grants to the Secured Party a security interest
in the Collateral as described on the attached Exhibit "A", which are
collectively described as the "Assets" in the Promissory Note, dated on the even
date herewith with DTS, as MAKER, (the "Note"), together with all proceeds
thereof, until full payment of the sum of Four Hundred Thousand dollars
($400,000) in lawful money of the United States of America is made to the order
of the Secured Party. The Obligation for payment as described herein shall be
secured by the Collateral held by the Debtor or its licensee at any of its
places of business. Debtor agrees to execute any and all documents requested by
Secured Party to perfect its secured interest, including financing statements
and UCC-1 filings, and in default thereof appoints Secured Party
Attorney-in-Fact to execute such documents.

Risk of Loss. The Collateral is to remain in the possession of the Debtor or its
licensee, at all times, at the Debtor's risk of loss or destruction. The
possession by the Debtor or its licensee shall continue as long as the
provisions of this Security Agreement are observed.

Release of Debtor. No transfer, renewal, extension, or assignment of this
Security Agreement or any interest hereunder, and no loss, damage or destruction
of the Collateral, shall release the Debtor from the Obligations described
herein. Debtor shall be released from all security interests and corresponding
lien of the Secured Party upon complete satisfaction of the Obligation.

Use of Collateral. The Debtor or its licensee shall at all times keep the
Collateral free of all taxes, liens and encumbrances, and any sums of money that
may be paid by the Secured Party in release or discharge thereof shall be
payable on demand as an additional part of the Obligation secured hereby. The
Debtor or its licensee shall not use the collateral in any manner other than in
the ordinary course of business. The Debtor or its licensee shall not pledge,
loan, grant or create any other additional security interest in the Collateral
until the Obligations described herein have been discharged, and shall not
transfer or otherwise dispose of the Collateral except as provided in this
Agreement. The Secured Party shall have the right to inspect the Collateral at
any reasonable time or times during the continuance of this Agreement.

Sale or Licensing of Collateral in Ordinary Course of Business. Debtor may sell
or license the Collateral in the ordinary course of business; provided, however
that any and all proceeds generated by the sale or licensing of the Collateral,
in whatever form, shall be fully and faithfully accounted for.

Default. (a) Should Debtor default in the prompt payment of any Obligation or in
the due performance of or compliance with any of the terms, provisions or
conditions of this Agreement, the Note, or any other document executed in
connection therewith (collectively "Security Documents") or a proceeding in
bankruptcy, insolvency, receivership or reorganization is instituted by or
against the Debtor or its property or the business of the Debtor is in any way
liquidated, or the Secured Party reasonably deems itself insecure of the
Collateral or any part thereof is in danger of loss, misuse, seizure, or
confiscation, the Secured Party shall have all the rights and remedies provided
in the Uniform Commercial Code in force in the State of Florida at the date of
execution of this Security Agreement. The Secured Party or any Sheriff or other
officer of the law may take immediate possession of the Collateral, including
any attachments or accessories thereto, without demand or further notice and
without legal process. (b) Notwithstanding anything contained herein to the
contrary, payment for any principal and interest shall be due and payable in
accordance with the terms of the Note. Failure of Debtor to pay after the
applicable cure period to pay expires, pursuant to said terms, shall constitute
a material default hereunder and all rights and remedies accorded Secured Party
within this Agreement, at law and in equity shall be available.

<PAGE>

                                        4

Attorney's Fees. In the event of repossession of the Collateral, the Secured
Party shall have such rights and remedies as provided and permitted by law for
the purpose of recovering and disposing of the Collateral. The Debtor shall pay
all attorneys fees and legal expenses incurred by the Secured Party in the event
repossession of the Collateral is required.

Governing Law/Venue. This Agreement shall be construed and governed in
accordance with the laws of the State of Florida and venue shall be in Gwinnett
County, Georgia.

Binding Effect. This Agreement shall be binding upon the parties, their heirs,
executors, personal representatives, successors or assigns, where permitted.

Entire Agreement. This Agreement is the entire agreement between Debtor and
Secured Party. No addition, alteration, modification hereto and no waiver of any
of the provisions hereof shall be valid unless made in writing and executed by
Debtor and Secured Party.

IN WITNESS WHEREOF, this Security Agreement was signed and executed on this 29th
day of December, 1999.

                                   DIGITAL TRANSMISSION SYSTEMS, INC.

                                   Per:
                                        ----------------------------------
                                        Andres C. Salazar
                                        Chief Executive Officer

                                   WI-LAN INC.

                                   Per:
                                        ----------------------------------
                                        Hatim Zaghloul
                                        Chairman and Chief Executive Officer

<PAGE>

                                   EXHIBIT "A"

The term "Assets" shall include:

Assets.

(a)      All furniture, fixtures, equipment, inventory, stock in trade, accounts
         receivable, contract rights, tangible or intangible property, including
         without limitation all patents, trademarks, trade names, service marks,
         copyrights or other intangible property rights, and registrations or
         applications for registration thereof, and any other personal property
         now or hereafter owned by Debtor.

(b)      All accessions to, substitutions for, and all replacement of, products
         and cash and non-cash proceeds of (a) above.THIS DEBENTURE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED (THE "SECURITIES ACT") OR ANY APPLICABLE STATE SECURITIES LAW AND MAY
NOT BE TRANSFERRED UNLESS (i) THERE IS AN EFFECTIVE REGISTRATION STATEMENT UNDER
THE SECURITIES ACT OR (ii) IN THE OPINION OF COUNSEL ACCEPTABLE TO THE COMPANY,
REGISTRATION UNDER THE SECURITIES ACT OR SUCH APPLICABLE STATE SECURITIES LAWS
IS NOT REQUIRED IN CONNECTION WITH SUCH TRANSFER.

                       DIGITAL TRANSMISSION SYSTEMS, INC.
              11.50% Subordinated Debenture due September 25, 2002

No. ________                                                    Atlanta, Georgia
$4,000,000.00                                                 September 25, 1977

         FOR VALUE RECEIVED, Digital Transmission Systems, Inc., a Delaware
corporation (the "Company"), promises to pay to the order of Sirrom Capital
Corporation d/b/a Tandem Capital, a Tennessee corporation ("Purchaser"),
pursuant to the Debenture Purchase Agreement (as hereinafter defined) at such
place as Purchaser may from time to time designate in writing, in lawful money
of the United States of America and in immediately available funds, by automatic
debit, the principal sum of Four Million Dollars ($4,000,000.00) and any accrued
but unpaid interest thereon.

         This Debenture is referred to in and is execute and delivered pursuant
to, a Debenture Purchase Agreement dated of even date herewith between the
Company and Purchaser (the "Debenture Purchase Agreement"), to which reference
is hereby made for a statement of the terms and conditions under which this
Debenture may be repaid and accelerated. Capitalized terms not otherwise defined
herein shall have the meanings ascribed to them in the Debenture Purchase
Agreement.

         Interest shall accrue from the date of issue of this Debenture at the
rate of 11.50% per annum, payable quarterly by automatic debit on the first day
of each March, June, September and December, commencing December 1, 1997, and
ending at maturity, to mature on September 25, 2002.

         Interest shall be computed on the basis of a 360-day year and the
actual number of days elapsed.

         Any principal payment due under this Debenture not paid when due,
whether at stated maturity, by notice of repayment, by acceleration or
otherwise, and any accrued but unpaid interest shall, to the extent permitted by
applicable law, thereafter bear interest (compounded monthly and payable upon
demand) at an annual rate of 15% in respect of such principal and such unpaid
interest until such unpaid amounts have been paid in full (whether before or
after judgment).

<PAGE>

                                                                               2

         This Debenture is subject to (i) optional redemption by the Company
without penalty and as provided by Section 1.2 of the Debenture Purchase
Agreement, and (ii) mandatory redemption at the election of the holder and as
provided by Section 1.3 of the Debenture Purchase Agreement. All payments made
hereunder shall be applied first to interest and then to outstanding principal.

         If payment hereunder becomes due and payable on a Saturday, Sunday, or
legal holiday, under the laws of the State of Tennessee, the due date thereof
shall be extended to the next succeeding business day.

         Demand, presentment, protest, diligence, notice of dishonor, and any
other formality are hereby expressly waived by the Company and any endorser or
guarantor.

         If there is any default under this Debenture, and this Debenture is
placed in the hands of an attorney for collection, or is collected through any
court, including any bankruptcy court, the Company promises to pay to the order
of the holder hereof such holder's reasonable attorneys' fees and court costs
actually incurred in collecting or attempting to collect or securing or
attempting to secure this Debenture or enforcing the holder's rights with
respect to the Collateral, to the extent allowed by the laws of the State of
Tennessee or any state in which any Collateral is situated.

         THIS DEBENTURE HAS BEEN DELIVERED IN, AND SHALL BE CONSTRUED IN
ACCORDANCE WITH AND GOVERNED BY THE LAWS OF, THE STATE OF GEORGIA APPLICABLE TO
CONTRACTS MADE AND TO BE PERFORMED THEREIN WITHOUT REGARD TO THE CONFLICTS OF
LAW PROVISIONS THEREOF.

         The holder of this Debenture may, with or without notice to any party,
and without affecting the obligations of any maker, surety, guarantor, endorser,
accommodation party, or any other party to this Debenture (i) extend the time
for payment of either principal or interest from time to time, (ii) release or
discharge any one or more parties liable on the Debenture, (iii) suspend the
right to enforce this Debenture with respect to any persons, (iv) change,
exchange, or release any property in which the holder has any interest securing
this Debenture, (v) justifiably or otherwise, impair any of the Collateral or
suspend the right to enforce against any such Collateral, and (vi) at any time
it deems it necessary or proper, call for and, should it be made available,
accept, as additional security, the signature or signatures of additional
parties or a security interest in property of any kind or description or both.

         This Debenture is subordinated to certain other indebtedness of the
Company to the extent and with the effect set forth in the Debenture Purchase
Agreement.

         This Debenture is registered on the books of the Company and is
transferable only by surrendered thereof at the principal office of the Company
at

<PAGE>

                                                                               3

3000 Northwoods Parkway, Building 330, Norcross, Georgia 30071, or such other
address as the Company shall have advised the holder of the Debenture in
writing, duly endorsed or accompanied by a written instrument of transfer duly
executed by the registered holder of this Debenture or its attorney duly
authorized in writing. Payment of or on account of principal, premium, if any,
and interest on this Debenture shall be made only to or upon the order in
writing of the registered holder thereof.

         Any provision herein, or in the Debenture Purchase Agreement, or any
other document executed or delivered in connection herewith or therewith, or in
any other agreement or commitment, whether written or oral, expressed or
implied, to the contrary notwithstanding, neither the Purchaser nor any holder
hereof shall in any event be entitled to receive or collect, nor shall any
amounts received hereunder be credited, so that Purchaser or any holder hereof
shall be paid, as interest, a sum greater than the maximum amount permitted by
applicable law to be charged to the person primarily obligated to pay this
Debenture at the time in question. If any construction of this Debenture or the
Debenture Purchase Agreement, or any and all other papers, agreements or
commitments, indicate a different right given to Purchaser or any holder hereof
to ask for, demand, or receive any larger sum as interest, such is a mistake in
calculation or wording which this clause shall override and control, it being
the intention of the parties that this Debenture, the Debenture Purchase
Agreement, and all other documents executed or delivered in connection herewith
shall in all ways comply with applicable law and proper adjustments shall
automatically be made accordingly. If Purchaser or any holder hereof ever
receives, collects, or applies as interest, any sum in excess of the maximum
amount permitted by applicable law, if any, such excess amount shall be applied
to the reduction of the unpaid principal balance of this Debenture, and if this
Debenture is paid in full, any remaining excess shall be paid to the Company. In
determining whether or not the interest paid or payable, under any specific
contingency, exceeds the maximum amount permitted by applicable law, if any, the
Company and any holder hereof shall, to the maximum extent permitted under
applicable law: (i) characterize any non-principal payment as an expense or fee
rather than as interest, and (ii) "spread" the total amount of interest
throughout the entire term of the Debenture.

                     [rest of page intentionally left blank]

<PAGE>

                                                                               4

         IN WITNESS WHEREOF, the Company has caused this Debenture to be
executed in its corporate name by the undersigned officer, thereunto duly
authorized.

                                        DIGITAL TRANSMISSION SYSTEMS, INC.

                                        By:  /s/ Andres C. Salazar
                                             -----------------------------
                                        Name:    Andres C. Salazar
                                             -----------------------------
                                        Title:   President and CEO
                                             -----------------------------

Pay to the order of WI-LAN INC.

     without recourse

          January 7, 2000

                                        FINOVA MEZZANINE CAPITAL INC.
                                        (f/k/a Sirrom Capital Corporation)

                                        By: /s/ Donald F. Barrirkman
                                            -----------------------------
                                            Donald F. Barrirkman, Vice President

<PAGE>

                                                                               5

                    THIRD AMENDMENT TO SUBORDINATED DEBENTURE

         This Third Amendment to the Subordinated Debenture ("Amendment") is
made and entered into as of the 7th day of January, 2000, by and between DIGITAL
TRANSMISSION SYSTEMS, INC. (the "Company"), a Delaware corporation, and WI-LAN,
INC. (the "Transferee").

                              W I T N E S S E T H :

         WHEREAS, Finova Mezzanine Capital Inc. ("Finova") and the Company
previously executed that 11.5% Subordinated Debenture due September 25, 2002, in
the original principal amount of $4,000,000, as amended by that First Amendment
to Subordinated Debenture dated as of October 21, 1998 and the Second Amendment
to the Subordinated Debenture dated as of February 5, 1999 (the "Debenture");

         WHEREAS, effective the date hereof, Finova has transferred the
Debenture to Transferee and immediately upon such transfer Transferee exercised
its conversion rights with respect to $1,310,000 principal amount of the
Debenture;

         NOW, THEREFORE, for valuable consideration, the receipt and sufficiency
of which are acknowledged, it is agreed as follows:

         1. The Debenture is hereby amended so that the Principal Amount of the
Debenture shall be $690,000.

         2. The Debenture remains in full effect, as amended hereby.

            [The Remainder of this page is intentionally left blank]

<PAGE>

                                                                               6

Executed as of the dated stated above.

                                        DIGITAL TRANSMISSION SYSTEMS, INC.

                                        By:  /s/ Andres C. Salazar
                                             -----------------------------
                                        Title:   Chief Executive Officer
                                             -----------------------------

                                        WI-LAN, INC.

                                        By:       [Signature Not Legible]
                                             -----------------------------
                                        Title:    Chief Executive Officer
                                             -----------------------------

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