|SUPPLEMENTAL INDENTURE


SUPPLEMENTAL
INDENTURE (this Supplemental Indenture) executed as of August 14, 2002 and
made effective as of May 29, 2002, by and among Arch Wireless Holdings, Inc., a Delaware
corporation (the Company), Arch Wireless Communications, Inc., a Delaware
corporation (Arch), Arch Wireless, Inc., a Delaware corporation (the
Parent), and the direct and indirect subsidiaries of the Parent listed on
Schedule I hereto (such subsidiaries, the Subsidiary Guarantors, and
together with Arch and the Parent, herein the Guarantors) and The Bank of New
York, a New York banking corporation, as Trustee (the Trustee).


RECITALS


WHEREAS,
the Company, the Guarantors and the Trustee have heretofore executed and delivered that
certain Indenture, dated as of May 29, 2002 (the Indenture), with respect to
the Companys 10% Senior Subordinated Secured Notes Due 2007 (the Notes);


WHEREAS,
Section 8.02 of the Indenture provides that the Company and the Guarantors, when
authorized by a Board Resolution, and the Trustee, together with the written consent of
the Majority Noteholders, may, under certain circumstances, enter into an indenture or
indentures supplemental to the Indenture for the purpose of adding any provisions to or
changing in any manner or eliminating or waiving (subject to Section 4.03 of the
Indenture) any of the provisions of the Indenture or of modifying in any manner the rights
of the Holders under the Indenture;


WHEREAS,
the Company desires to amend certain sections of the Indenture, effective as of
May 29, 2002, to correct certain inconsistencies in the terms of the Indenture, and
in connection therewith, the Company has been soliciting written consents of the Holders
to the amendments to the Indenture set forth herein (and to the execution of this
Supplemental Indenture), and the Company has now obtained such written consents from the
Holders of a majority in the aggregate principal amount of the outstanding Notes;
accordingly, this Supplemental Indenture and the amendments set forth herein are
authorized pursuant to Section 8.02 of the Indenture; and


WHEREAS,
the execution and delivery of this Supplemental Indenture has been duly authorized by the
parties hereto, and all other acts necessary to make this Supplemental Indenture a valid
and binding supplement to the Indenture, effectively amending and supplementing the
Indenture as set forth herein, have been duly taken;


NOW,
THEREFORE, in consideration of the above premises and for other good and valuable
consideration, the receipt of which is hereby acknowledged, it is mutually agreed, for the
equal and proportionate benefit of all Holders, as follows:




ARTICLE ONE


Upon
execution of this Supplemental Indenture by the Company and the parties hereto, then
automatically (without further act by any person) with respect to all outstanding Notes,
the Indenture is hereby amended, effective as of May 29, 2002, in the following
respects:


1.1
Section 10.21 of the Indenture shall be deleted in its entirety, and the following is
substituted in lieu thereof:


"SECTION 10.21  
        Minimum EBITDA.


The
Note Parties shall have, as of the last day of each quarter set forth below, EBITDA for
such quarter of not less than the following:
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | Quarter Ending     | Minimum Quarterly EBITDA
(dollars in millions) | 
| | ------------------ | ---------------------------------------------- | 
| | June 30, 2002      | 46.5                                           | 
| | September 30, 2002 | 45.5                                           | 
| | December 31, 2002  | 42.9                                           | 
| | March 31, 2003     | 41.0                                           | 
| | June 30, 2003      | 39.4                                           | 
| | September 30, 2003 | 37.9                                           | 
| | December 31, 2003  | 36.6                                           | 
| | March 31, 2004     | 34.7                                           | 
| | June 30, 2004      | 34.4                                           | 
| | September 30, 2004 | 33.9                                           | 
| | December 31, 2004  | 34.0                                           | 
| | March 31, 2005     | 33.0                                           | 
| | June 30, 2005      | 33.9                                           | 
| | September 30, 2005 | 34.2                                           | 
| | December 31, 2005  | 34.7                                           | 
| | March 31, 2006     | 33.1                                           | 
| | June 30, 2006      | 34.6                                           | 
| | September 30, 2006 | 36.1                                           | 
| | December 31, 2006  | 37.4                                           | 
| | March 31, 2007     | 36.6                                           | 

|1.2     
Section 10.24 of the Indenture  shall be deleted in its entirety, and the following is
substituted in lieu thereof:


SECTION 10.24 
         Non-Device Capital Expenditures.


The
Note Parties will not permit: (a) One-Way Capital Expenditures (other than One-Way Capital
Expenditures made in respect of paging and messaging devices (One-Way Device
Capital Expenditures)); and (b) Two-Way Capital Expenditures (other
than Two-Way Capital Expenditures made in respect of paging and messaging devices
(Two-Way Device Capital Expenditures)) to be made or
incurred for each of the quarters set forth below such that the cumulative amounts would
be in excess of the maximum cumulative amounts set forth below:
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|Quarter Ending     | Maximum Cumulative One Way
Capital Expenditures
(dollars in millions) | Maximum Cumulative Two Way
Capital Expenditures
(dollars in millions)
|------------------ | --------------------------------------------------------------------- | ---------------------------------------------------------------------
|June 30, 2002      | 2.8                                                                   | 3.5                                                                  
|September 30, 2002 | 4.9                                                                   | 9.7                                                                  
|December 31, 2002  | 6.7                                                                   | 12.8                                                                 
|March 31, 2003     | 8.1                                                                   | 14.2                                                                 
|June 30, 2003      | 9.3                                                                   | 15.6                                                                 
|September 30, 2003 | 10.6                                                                  | 16.9                                                                 
|December 31, 2003  | 11.7                                                                  | 18.1                                                                 
|March 31, 2004     | 12.8                                                                  | 19.2                                                                 
|June 30, 2004      | 13.9                                                                  | 20.4                                                                 
|September 30, 2004 | 14.9                                                                  | 21.5                                                                 
|December 31, 2004  | 15.8                                                                  | 22.8                                                                 
|March 31, 2005     | 16.7                                                                  | 26.0                                                                 
|June 30, 2005      | 17.6                                                                  | 29.5                                                                 
|September 30, 2005 | 18.4                                                                  | 33.0                                                                 
|December 31, 2005  | 19.2                                                                  | 36.7                                                                 
|March 31, 2006     | 19.9                                                                  | 41.0                                                                 
|June 30, 2006      | 20.6                                                                  | 45.5                                                                 
|September 30, 2006 | 21.2                                                                  | 50.1                                                                 
|December 31, 2006  | 21.8                                                                  | 54.9                                                                 
|March 31, 2007     | 22.3                                                                  | 56.4                                                                 

|provided that any individual
commitment for such One-Way Capital Expenditures other than One-Way Device Capital
Expenditures or Two-Way Capital Expenditures other than Two-Way Device Capital
Expenditures in excess of $2,500,000 shall require the prior approval of the Board of
Directors of the Parent.


1.3     Section 10.25 of the Indenture shall be
deleted in its entirety, and the following is substituted in lieu thereof:


SECTION 10.25  
        Device Capital Expenditures.


The
Note Parties will not permit: (a) One-Way Device Capital Expenditures; and (b) Two-Way
Device Capital Expenditures to be made or incurred for each of the quarters set forth
below such that the cumulative amounts would be in excess of the maximum cumulative
amounts set forth below:
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|Quarter Ending     | Maximum Cumulative One Way
Capital Expenditures
(dollars in millions) | Maximum Cumulative Two Way
Capital Expenditures
(dollars in millions)
|------------------ | --------------------------------------------------------------------- | ---------------------------------------------------------------------
|June 30, 2002      | 14.3                                                                  | 18.2                                                                 
|September 30, 2002 | 24.7                                                                  | 36.9                                                                 
|December 31, 2002  | 34.8                                                                  | 58.6                                                                 
|March 31, 2003     | 46.6                                                                  | 82.2                                                                 
|June 30, 2003      | 58.4                                                                  | 105.8                                                                
|September 30, 2003 | 70.3                                                                  | 130.0                                                                
|December 31, 2003  | 82.2                                                                  | 154.2                                                                
|March 31, 2004     | 91.6                                                                  | 176.8                                                                
|June 30, 2004      | 101.0                                                                 | 199.3                                                                
|September 30, 2004 | 109.8                                                                 | 221.6                                                                
|December 31, 2004  | 118.6                                                                 | 243.8                                                                
|March 31, 2005     | 126.5                                                                 | 265.9                                                                
|June 30, 2005      | 134.4                                                                 | 288.0                                                                
|September 30, 2005 | 141.9                                                                 | 310.1                                                                
|December 31, 2005  | 149.5                                                                 | 332.2                                                                

|
|

|Quarter Ending     | Maximum Cumulative One Way
Capital Expenditures
(dollars in millions) | Maximum Cumulative Two Way
Capital Expenditures
(dollars in millions)
|------------------ | --------------------------------------------------------------------- | ---------------------------------------------------------------------
|March 31, 2006     | 156.2                                                                 | 353.6                                                                
|June 30, 2006      | 162.9                                                                 | 374.8                                                                
|September 30, 2006 | 169.4                                                                 | 395.5                                                                
|December 31, 2006  | 175.7                                                                 | 415.7                                                                
|March 31, 2007     | 181.0                                                                 | 435.3                                                                

|providedthat (i) any
commitments (measured in terms of number of devices) for such One-Way Device Capital
Expenditures in either the Companys numerical or alphanumerical product lines, each
measured separately, in excess of the prior three months Gross Placements for such
product line and (ii) any commitments (measured in terms of number of devices) for such
Two-Way Device Capital Expenditures in excess of the prior two months Gross
Placements shall each require the prior approval of the Board of Directors of the Parent;
provided, further, that (x) if One-Way SRM Revenue for the immediately
preceding Fiscal Quarter is reported below Planned One-Way SRM Revenue for such Fiscal
Quarter, the maximum amount of permitted One-Way Device Capital Expenditures shall be
reduced by one-half of the percentage by which such reported One-Way SRM Revenue is below
Planned One-Way SRM Revenue or (y) if Two-Way SRM Revenue for the immediately preceding
Fiscal Quarter is reported below Planned Two-Way SRM Revenue for such Fiscal Quarter, the
maximum amount of permitted Two-Way Device Capital Expenditures shall be reduced by
one-half of the percentage by which such reported Two-Way SRM Revenue is below Planned
Two-Way SRM Revenue.


ARTICLE TWO


2.1
All terms used in this Supplemental Indenture which are defined in the Indenture and not
otherwise defined herein shall have the meanings assigned to such terms in the Indenture.


2.2
All of the provisions of this Supplemental Indenture shall be deemed to be incorporated
in, and made part of, the Indenture effective as of May 29, 2002, and the Indenture,
as amended and supplemented by this Supplemental Indenture, shall be read, taken and
construed as one and the same instrument and shall be binding upon all the Holders.


2.3
This Supplemental Indenture may be executed in any number of counterparts, each of which
so executed shall be deemed to be an original, but all such counterparts shall together
constitute but one and the same instrument.


2.4
In case any provision in this Supplemental Indenture shall be invalid, illegal or
unenforceable, the validity, legality and enforceability of the remaining provisions shall
not in any way be affected or impaired thereby.



2.5
Nothing in this Supplemental Indenture, express or implied, shall give any person, other
that the parties hereto and their successors hereunder and the Holders, any benefit or any
legal or equitable right, remedy or claim under this Supplemental Indenture. Except as
expressly supplemented or amended as set forth in this Supplemental Indenture, the
Indenture is hereby ratified and confirmed, and all the terms, provisions and conditions
thereof shall be and continue in full force and effect. The Trustee accepts the trusts
created by the Indenture, as amended and supplemented by this Supplemental Indenture, and
agrees to perform the same upon the terms and conditions in the Indenture as amended and
supplemented by this Supplemental Indenture.


2.6
The Trustee shall not be responsible in any matter whatsoever for or in respect of the
validity or sufficiency of this Supplemental Indenture, except with respect to the
execution hereof by the Trustee, or for or in respect of the recitals contained herein,
all of which are made solely by the Company and the Guarantors.


     * * * * * * *


IN
WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly
executed, all as of the day and year first written above, and made effective as of May 29,
2002.
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | Arch Wireless, Inc.
Arch Wireless Holdings, Inc.
Arch Wireless Communications, Inc.
Arch Connecticut Valley, Inc.
Arch Communication Enterprises, LLC
Archtel, Inc.
MobileMedia Communications, Inc.
Mobile Communications Corporation of America
MobileMedia License Co., L.L.C.
Benbow Investments, Inc.
Paging Network, Inc.
PageNet, Inc.
Paging Network Finance Corp.
Paging Network International, Inc.
Paging Network of America, Inc.
Paging Network of Colorado, Inc.
Paging Network of Michigan, Inc.
Paging Network of Northern California, Inc.
Paging Network of San Francisco, Inc.
Paging Network Canadian Holdings, Inc.
PageNet SMR Sub, Inc.

| |                                          
| | -----------------------------------------
| | As to each of the foregoing:             
| | By:_________________________             
| | Name:______________________              
| | Title:________________________           
| | The Bank of New York, as Collateral Agent
| | By:_________________________             
| | Name:______________________              
| | Title:________________________           

|Schedule I


Arch Wireless, Inc.Arch Wireless Communications, Inc.
Arch Connecticut Valley, Inc.Arch Communication Enterprises, LLCArchtel, Inc.
MobileMedia Communications, Inc.Mobile Communications Corporation of America
MobileMedia License Co., L.L.C.Benbow Investments, Inc.Paging Network, Inc.
PageNet, Inc.Paging Network Finance Corp.Paging Network International, Inc.
Paging Network of America, Inc.Paging Network of Colorado, Inc.Paging Network of Michigan, Inc.
Paging Network of Northern California, Inc.Paging Network of San Francisco, Inc.
Paging Network Canadian Holdings, Inc.PageNet SMR Sub, Inc.
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------