April 16, 2002

Ms. Deborah Schmelzer
Vice President - Finance
Horizon Personal Communications, Inc.
52 East Main Street
Chillicothe, Ohio 45601-0480

LETTER OF UNDERSTANDING:

This letter will summarize the terms by which SBA Towers,  Inc.  ("SBA") and its
affiliates  (collectively  with  SBA,  the "SBA  Group")  and  Horizon  Personal
Communications,  Inc. ("Horizon") and its affiliates (collectively with Horizon,
the "Horizon Group") agree, in lieu of the payment of development fees by SBA to
Horizon under the Site  Development  Agreement dated August 17, 1999 between SBA
and  Horizon  (as  previously  or  hereafter  amended,   the  "Site  Development
Agreement"),  to issue  credits  on unpaid  and  future  services  fees due from
members of the Horizon  Group to SBA under  various  other  existing  and future
agreements  entered  into  between  members of the SBA Group and  members of the
Horizon  Group  (collectively,  the "Other  Agreements").  Such  credits will be
applied as offsets on existing  and  subsequent  invoices as a reduction  to the
amount owed by members of the Horizon Group to the SBA Group for services.

Please confirm your  understanding  of this arrangement by signing below. If you
have any questions or comments, please don't hesitate to call.



SBA TOWERS, INC.

By:__/s/ Jack Fieldor_____________________
Name:_____Jack Fieldor________________
Title:_____CAO_______________


ACCEPTED AND AGREED TO:

HORIZON PERSONAL COMMUNICATIONS, INC.

By:_____/s/ Pete Holland__________________
Name:_______Pete Holland______________
Title:______CFO______________