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August 2, 1999

Dear CAI Shareholder:

I cordially invite you to attend a special meeting of the shareholders of
CAI Wireless Systems, Inc. to be held on August 31, 1999, at 11:00 a.m., Eastern
time, at The Goodwin Hotel, One Haynes Street, Hartford, Connecticut 06103. This
special meeting was demanded by MCI WorldCom in accordance with Connecticut law
and CAI's bylaws.

At this meeting, shareholders of record on July 28, 1999 will vote upon
three proposals as follows:

- to consider and vote upon a proposal to remove the existing CAI board;

- to consider and vote upon a proposal to amend Article IV, Section 1 of
CAI's bylaws; and

- to consider and vote upon a proposal to elect MCI WorldCom's nominees to
the CAI board.

This is the second special meeting to be held on August 31, 1999, and will
be held after the special meeting of CAI shareholders that relates to the
proposed merger of a wholly-owned subsidiary of MCI WorldCom with CAI. The white
proxy card and accompanying material for the merger special meeting was sent to
you previously.

Included with this mailing is a notice of the second special meeting of
shareholders and certain information relating to the actions proposed to be
taken at the second special meeting.

NEITHER CAI, MCI WORLDCOM NOR ANY OTHER PERSON IS SOLICITING PROXIES WITH
REGARD TO THIS SPECIAL MEETING.

Sincerely,

/s/ Jared E. Abbruzzese
JARED E. ABBRUZZESE
Chairman of the Board of Directors
and Chief Executive Officer

CAI WIRELESS SYSTEMS, INC.
18 CORPORATE WOODS BOULEVARD
ALBANY, NEW YORK 12211
TELEPHONE: (518) 462-2632

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS
TO BE HELD ON AUGUST 31, 1999

To Our Shareholders:

We are contacting you to notify you that MCI WORLDCOM, Inc., a Georgia
corporation beneficially owning greater than ten percent (10%) of the issued and
outstanding common stock of CAI Wireless Systems, Inc., a Connecticut
corporation, has demanded, pursuant to Section 33-696(a)(2) of the Connecticut
Business Corporation Act, a special meeting of the shareholders of CAI. We will
hold that special meeting at 11:00 a.m., Eastern time, on August 31, 1999, at
The Goodwin Hotel, One Haynes Street, Hartford, Connecticut 06103. The meeting
demanded by MCI WorldCom will follow the shareholders meeting described in the
proxy materials previously forwarded to you and will be held for the following
purposes:

1. To consider and vote upon a proposal to remove the existing Board of
Directors of CAI, consisting of Jared E. Abbruzzese, Paul M. Albert, Vernon
L. Fotheringham, Robert D. Happ, Martin G. Mand and John B. Newman, pursuant
to Section 2 of Article IV of CAI's Bylaws and in accordance with Section
33-742 of the Connecticut Business Corporation Act;

2. To consider and vote upon a proposal to amend Article IV, Section 1
of the bylaws of CAI in accordance with Section 33-806(b) of the Connecticut
Business Corporation Act to, among other things, fix the number of directors
at two, as set forth on Appendix A-1 hereto;

3. To consider and vote upon a proposal to elect Charles T. Cannada and
Bernard J. Ebbers to the Board of Directors of CAI (for additional
information regarding the nominees, please see Appendix A-2 hereto); and

4. To transact any other business that is properly brought before such
special meeting or any adjournment or postponement of such special meeting.

The CAI board fixed the close of business on July 28, 1999 as the record
date to determine the shareholders who are entitled to receive notice of and to
vote at the special meeting demanded by MCI WorldCom and any adjournment or
postponement of that special meeting. Therefore, only shareholders of record on
that date are entitled to receive notice of, and to vote at, such special
meeting or any adjournment or postponement of it.

Shareholders of record on the record date are entitled to one vote per CAI
common share, exercisable in person or by properly executed proxy, upon each
matter properly submitted for the vote of shareholders at the special meeting
demanded by MCI WorldCom. The presence, in person or by properly executed proxy,
of the holders of the outstanding CAI common shares entitling them to exercise a
majority of the voting power is necessary to constitute a quorum at such special
meeting. Abstentions will be counted as present for the purpose of determining
the presence of a quorum at the special meeting demanded by MCI WorldCom.

The affirmative vote of the holders of a majority of the votes cast by the
CAI common shares entitled to vote at the special meeting demanded by MCI
WorldCom is required to remove the existing CAI board members and to amend CAI's
bylaws, once a quorum is present. CAI directors are elected by a plurality of
votes cast by the CAI common shares entitled to vote at the special meeting
demanded by MCI WorldCom at which a quorum is present. The required vote of the
shareholders on the proposals to be considered at such special meeting is based
on the total number of CAI common shares outstanding as of the record date.
Abstentions with respect to voting on the proposals to be considered at the
special meeting demanded by MCI WorldCom will have the effect of a negative
vote.

MCI WorldCom recently completed the acquisition of 10,684,140 CAI common
shares, representing approximately 62.0% of the outstanding CAI common shares
entitled to vote on the proposals to be considered at the special meeting
demanded by MCI WorldCom. MCI WorldCom intends to vote its CAI

common shares in favor of each of the proposals to be considered at such special
meeting. Accordingly, the proposals to be considered at the special meeting
demanded by MCI WorldCom do not require the approval of any CAI shareholder
other than MCI WorldCom.

In the event the merger of a wholly-owned subsidiary of MCI WorldCom with
and into CAI is not approved by shareholders, MCI WorldCom expects to review its
alternatives with respect to CAI, which may include, among other things,
resubmitting the proposed merger, and/or submitting a merger agreement on
different terms between CAI and MCI WorldCom or one of its subsidiaries.

MCI WorldCom may also explore other forms of transactions with CAI or its
subsidiaries, which may include stock sales, as described below, commercial
transactions, or other types of transactions. CAI has previously reported that
it believes it has sufficient cash to fund its capital requirements through
November 1999 and that, if such merger is not approved, CAI would not have
sufficient cash to implement its business plan. In view of CAI's liquidity
needs, MCI WorldCom may propose to CAI that MCI WorldCom invest additional
capital in CAI in exchange for additional CAI shares of capital stock. These
additional shares, if so acquired, might result in MCI WorldCom's ownership of
an aggregate number of shares that would be sufficient to approve the merger.
Further, MCI WorldCom plans to review the businesses of CAI and make such
changes as it deems appropriate at the time, which could include causing CAI to
enter into commercial transactions, joint ventures, asset sales or other
possible transactions.

Please see "The Special Meeting--Record Date; Voting at the Special
Meeting," beginning on page 57, "Certain Information About CAI--Management"
beginning on page 76, "Certain Information About CAI--Change of Control;
Security Ownership of Certain Beneficial Owners and Management" beginning on
page 78, "The Merger--Interests of Certain Persons in the Merger" beginning on
page 29, and "The Merger--Description of Relationship Between MCI WorldCom and
CS Wireless" beginning on page 35 and "--Recent Events" beginning on page 36, in
the proxy statement relating to the proposed merger with MCI WorldCom for
certain information regarding (1) the number of CAI common shares outstanding as
of the record date, (2) the existing directors of CAI, (3) the ownership of CAI
common shares, (4) the interests of the directors and executive officers of CAI
in the proposed merger with MCI WorldCom, and (5) relationships between CAI and
MCI WorldCom.

CAI files annual, quarterly and special reports, proxy statements and other
information with the SEC. Pursuant to Rule 12g-4(a)(1)(i) under the Securities
Exchange Act of 1934, as amended, on April 29, 1999, CAI filed a Form 15 with
the SEC to deregister the CAI common shares under Section 12(g) of the Exchange
Act, which became effective on July 29, 1999. As a result, persons subject to
the insider trading rules of Section 16 of the Exchange Act or the filing
requirements of Section 13(d) of the Exchange Act, and CAI, with respect to,
among other things, the proxy and information statement rules under Section 14
of the Exchange Act, are no longer subject to such rules or requirements. In
addition, after completion of the merger, CAI intends to file a Form 15 with
regard to its reporting obligations under Section 15(d) of the Exchange Act.
Once that Form is effective, CAI will no longer be required to file periodic and
other reports required under the Exchange Act and the rules promulgated
thereunder. Notwithstanding CAI's intent to be relieved from the filing
requirements under the federal securities laws, the indenture governing CAI's
13% senior notes due 2004 requires CAI to make certain filings so long as such
notes remain outstanding.

Shareholders may read and copy any reports, statements or other information
that CAI files at the public reference facilities of the SEC at its principal
office at Judiciary Plaza, 450 Fifth Street, N.W., Room 1024, Washington DC
20549, and its regional offices at 7 World Trade Center, Suite 1300, New York,
New York 10048 and Citigroup Center, 500 W. Madison Street, Suite 1400, Chicago,
Illinois 60661. Shareholders may call the SEC at 1-800-SEC-0330 for further
information on the public reference rooms. CAI's filings with the SEC are also
available to the public from commercial document retrieval services and at the
web site maintained by the SEC at http://www.sec.gov.

We strongly encourage you to read carefully the documents CAI has filed with
the SEC.

We have decided to "incorporate by reference" information into this notice.
This means that we can disclose important information to you by referring you to
another document filed separately with the SEC.

The information incorporated by reference is considered to be a part of this
notice, except for any information that is superseded by other information that
is included in or incorporated by reference into this document.

This notice incorporates by reference the documents listed below that we
have previously filed with the SEC. These documents contain important
information about us.

CAI SEC FILINGS (SEC FILE NO. 0-22888) PERIOD
- -------------------------------------------------------- --------------------------------------------------------

Annual Report on Form 10-K Years ended March 31, 1999 and 1998

Quarterly Reports on Form 10-Q Quarters ended June 30, 1998, September 30, 1998 (as
amended by Form 10-Q/A filed on June 29, 1999) and
December 31, 1998 (as amended by Form 10-Q/A filed on
June 29, 1999)

Current Reports on Form 8-K Filed on July 2, 1998, July 16, 1998, August 4, 1998,
August 6, 1998, October 15, 1998, October 30, 1998,
April 28, 1999, June 16, 1999, June 29, 1999 and July
12, 1999

We also incorporate by reference any additional documents that we may file
with the SEC under Section 15(d) of the Exchange Act between the date of this
document and the date of the meeting. These may include periodic reports, such
as Quarterly Reports on Form 10-Q or Current Reports on Form 8-K. CAI
anticipates filing a Current Report on Form 8-K on or about August 2, 1999,
which report shall contain, as exhibits, the materials relating to each of the
special meetings to be held by CAI on August 31, 1999.

CAI may have sent to CAI shareholders some of the documents referenced
above, but shareholders can obtain any of them through CAI or the SEC. Documents
previously filed with the SEC and referenced in this notice, are available from
CAI without charge. Shareholders may obtain documents previously filed with the
SEC and referenced in this notice, by requesting them in writing at the
following address:

CAI Wireless Systems, Inc.
18 Corporate Woods Boulevard, Third Floor
Albany, New York 12211
Attention: Corporate Secretary
Telephone: (518) 462-2632

If you would like to request documents from CAI, please do so by August 24,
1999 to receive them before the special meeting.

Shareholders should rely only on the information contained or incorporated
by reference in this notice to vote their shares at the special meeting. CAI has
not authorized anyone to provide you with information that is different from
what is contained in this notice. This notice is dated August 2, 1999.
Shareholders should not assume that the information contained in the notice is
accurate as of any date other than such date, and the mailing of this notice to
shareholders will not create any implication to the contrary.

NEITHER CAI, MCI WORLDCOM OR ANY OTHER PERSON IS SOLICITING PROXIES WITH
REGARD TO THE SECOND SPECIAL MEETING.

By Order of the Board of Directors on
behalf of MCI WORLDCOM, Inc.,

WAYNE BARR, JR.
Corporate Secretary

Albany, New York
August 2, 1999

APPENDIX A-1
PROPOSED AMENDMENT TO CAI BYLAWS

MCI WorldCom proposes that Section 1 of Article IV of the CAI bylaws be
replaced in its entirety with the following:

SECTION 1. Number, Election and Term of Directors. Upon adoption of this
Section 1, the initial number of directors that shall constitute the full Board
of Directors shall be two. Thereafter, the number of directors that shall
constitute the full Board of Directors at any time shall be that number most
recently fixed by resolution of the Board of Directors, or shall be that number
of directors elected at the preceding Annual Meeting of Shareholders, plus the
number elected since such number, if any, to fill a vacancy created by an
increase in the size of the Board of Directors.

The term of the initial directors shall expire at the first shareholder's
meeting at which directors are elected. Thereafter, the terms of all other
directors shall expire at the next Annual Meeting of Shareholders following such
director's election. The term of a director elected to fill a vacancy expires at
the next shareholders' meeting at which directors are elected. Despite the
expiration of a director's term, the director shall continue to serve until the
director's successor is elected and qualifies or until there is a decrease in
the number of directors.

APPENDIX A-2
INFORMATION CONCERNING CERTAIN NOMINEES TO THE CAI BOARD OF DIRECTORS

Set forth below are the name, age, current business address and the present
principal occupation or employment and material occupations, positions, offices
or employment for the past five years of MCI WorldCom's two nominees to the CAI
Board of Directors. Neither Mr. Cannada nor Mr. Ebbers beneficially owns any CAI
common shares, and each disclaims beneficial ownership of the CAI common shares
owned by MCI WorldCom.

On September 14, 1998, MCI WorldCom acquired MCI Communications Corporation
("MCI"), pursuant to the merger of MCI with and into a wholly-owned subsidiary
of MCI WorldCom. Immediately prior to September 15, 1998, MCI WorldCom was named
WorldCom, Inc. References to service with MCI WorldCom prior to September 1993
include service with LDDS Communications, Inc., a Tennessee corporation, which
was the accounting, but not legal, survivor of a three-way merger with
Metromedia Communications Corporation and Resurgens Communications Group, Inc.

PRESENT PRINCIPAL OCCUPATION AND MATERIAL
NAME AND BUSINESS ADDRESS AGE POSITIONS HELD DURING PAST 5 YEARS
- ------------------------------ --- -------------------------------------------------------------------------

CHARLES T. CANNADA 40 Mr. Cannada serves as Senior Vice President, Corporate Development of MCI
MCI WORLDCOM, Inc. WorldCom. Prior to assuming this position in January 1995, Mr. Cannada
500 Clinton Center Drive served as Treasurer and Chief Financial Officer of MCI WorldCom. He
Clinton, Mississippi 39056 joined MCI WorldCom in 1989. He is also a director of Nova Corporation,
U.S.A. since May 1998, and of WAM!NET, Inc., since September 1998.

BERNARD J. EBBERS 57 Mr. Ebbers has been President and Chief Executive Officer of MCI WorldCom
MCI WORLDCOM, Inc. since April 1985. Mr. Ebbers has served as a director of MCI WorldCom
500 Clinton Center Drive since 1983.
Clinton, Mississippi 39056
U.S.A.

APPENDIX-1