CELLNET DATA SYSTEMS, INC.

               AMENDED AND RESTATED CERTIFICATE OF INCORPORATION



     CellNet Data Systems, Inc., a corporation organized and existing under and
by virtue of the Delaware General Corporation Law, hereby certifies as follows:

     1.   The name of this corporation is CellNet Data Systems, Inc. and the
original Certificate of Incorporation of the corporation was filed with the
Secretary of State of the State of Delaware on December 7, 1993.

     2.   This Restated Certificate of Incorporation was duly adopted in
accordance with the provisions of Sections 242 and 245 of the General
Corporation Law of the State of Delaware.  Pursuant to Sections 228, 242 and 245
of the General Corporation Law of Delaware, this Amended and Restated
Certificate of Incorporation restates and further integrates and further amends
the provisions of this corporation's Certificate of Incorporation.

     3.   The text of the Amended and Restated Certificate of Incorporation as
heretofore amended or supplemented is hereby restated and further amended to
read in its entirety as set forth in Schedule A attached hereto.

     IN WITNESS WHEREOF, this Amended and Restated Certificate of Incorporation
has been signed under the seal of the corporation this 25th day of April, 1997.


                          CELLNET DATA SYSTEMS, INC.



                          By: /s/JOHN M. SEIDL
                              ----------------------------
                              John M. Seidl, President and
                               Chief Executive Officer



ATTEST:


/s/DAVID L. PERRY
- -------------------------
David L. Perry, Secretary



                             SCHEDULE A

                RESTATED CERTIFICATE OF INCORPORATION
                                 OF
                     CELLNET DATA SYSTEMS, INC.



     FIRST.  The name of the corporation is CellNet Data Systems, Inc. (the
"Corporation").

     SECOND.  The address of the Corporation's registered office in the State of
Delaware is 1209 Orange Street, Wilmington, County of New Castle, Delaware
19801.  The name of its registered agent at such address is The Corporation
Trust Company.

     THIRD.  The purpose of the Corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of Delaware.

     FOURTH.  This Corporation is authorized to issue two classes of shares,
designated "Common Stock," $0.001 par value and "Preferred Stock," $0.001 par
value, respectively.  The number of shares of Common Stock authorized to be
issued is one hundred million (100,000,000) and the number of shares of
Preferred Stock authorized to be issued is fifteen million (15,000,000). The
Board of Directors shall have the authority to issue the authorized but
undesignated Preferred Stock from time to time in one or more series and to fix
the number of shares of such series and to determine the designation of any such
series and to determine or alter the powers, preferences, rights,
qualifications, limitations or restrictions granted to or imposed upon any
wholly unissued series.  The Board of Directors, within the limits and
restrictions stated in any resolution or resolutions of the Board of Directors
originally fixing the number of shares constituting any series, may increase or
decrease (but not below the number of shares in any such series then
outstanding) the number of shares of any series subsequent to the issue of
shares of that series.

     FIFTH.  The Board of Directors of the Corporation is expressly authorized
to make, alter or repeal the Bylaws of the Corporation.

     SIXTH.  Elections of directors need not be by written ballot except and to
the extent provided in the Bylaws of the Corporation.

     SEVENTH.   (a)  To the fullest extent permitted by the Delaware General
Corporation Law as the same exists or as may hereafter be amended, a director of
the Corporation shall not be personally liable to the Corporation or its
stockholders for monetary damages for breach of fiduciary duty as a director.

                (b)  The Corporation shall indemnify to the fullest extent
permitted by law any person made or threatened to be made a party to an action
or proceeding, whether criminal, civil, administrative or investigative, by
reason of the fact that he, his testator or intestate is or was a director


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or executive officer of the Corporation or any predecessor of the Corporation or
serves or served any other enterprise as a director or executive officer at the
request of the Corporation or any predecessor to the Corporation.  The
Corporation shall have the authority upon approval of the Board of Directors to
indemnify any other officer and employee of the Corporation.

                (c)  Neither any amendment nor repeal of this Article SEVENTH,
nor the adoption of any provision of the Corporation's Certificate of
Incorporation inconsistent with this Article SEVENTH, shall eliminate or reduce
the effect of this Article SEVENTH in respect of any matter occurring, or any
action or proceeding accruing or arising or that, but for this Article SEVENTH,
would accrue or arise, prior to such amendment, repeal or adoption of an
inconsistent provision.

     EIGHTH.    Until such time as the Corporation is a publicly-traded company
with more than 800 stockholders of record, in the election of directors, each
holder of stock of any class or series of the Corporation shall be entitled to
as many votes as shall equal the number of votes entitled to be cast for the
election of directors with respect to each holder's shares of stock multiplied
by the number of directors to be elected by each holder, and may cast all of
such votes for a single director or may distribute such votes among the number
of directors to be elected, provided, that, such holder has given notice of the
intention to cumulate votes as specified in the bylaws; notwithstanding the
foregoing, the right to cumulative voting shall exist until August 15, 1997, and
thereafter at such time as the Corporation is a publicly traded company with
more than 800 stockholders of record, such right to cumulative voting will be
eliminated.

     NINTH.     No action shall be taken by the stockholders of the Corporation
except at an annual or special meeting of the stockholders called in accordance
with the Bylaws and no action shall be taken by the stockholders by written
consent.  The affirmative vote of sixty-six and two thirds percent (66 2/3%) of
the then outstanding voting securities of the Corporation, voting together as a
single class, shall be required for the amendment, repeal or modification of the
provisions of this Article NINTH of this Amended and Restated Certificate of
Incorporation or Sections 2.3 and 2.5 of the Corporation's Bylaws.


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