CONFIDENTIAL TREATMENT REQUESTED

     Confidential Portions of this Agreement Which Have Been Redacted Are Marked
With  ("[***]").  The  Omitted  Material  Has  Been  Filed  Separately  With The
Securities and Exchange Commission.

                              MASTER SITE AGREEMENT

                                 by and between

                                SBA TOWERS, INC.

                                       and

                      HORIZON PERSONAL COMMUNICATIONS, INC.


<PAGE>
                        CONFIDENTIAL TREATMENT REQUESTED

                              MASTER SITE AGREEMENT

     THIS MASTER SITE AGREEMENT  (this "MSA") is made and entered into this ____
day of July,  1999 (the "Date of this MSA"),  by and  between  SBA Towers,  Inc.
("SBA"), and Horizon Personal Communications, Inc. ("Horizon").

                                    RECITALS:

     WHEREAS,  Horizon and Horizon Telcom,  Inc. have sold or has agreed to sell
to SBA fifty-six (56) towers and related  improvements ("SBA  Improvements") and
in connection  therewith  has either  conveyed or agreed to convey to SBA all of
Horizon's and Horizon  Telcom,  Inc.'s  right,  title and interest in and to the
land upon which the towers  were  constructed  or has  assigned or has agreed to
assign  to  SBA  all  of  Horizon's  right,  title  and  interest  in and to the
underlying   leases,   licenses  or   easements  as  set  forth  in  Schedule  1
(collectively, the "Ground Leases") attendant to those towers and related assets
purchased  pursuant  to the terms of the Asset  Purchase  Agreement  (the "APA")
entered into by and among SBA, Horizon,  and Horizon Telcom,  Inc. dated the ___
day of July, 1999 (individually a "Tower", collectively the "Towers");

     WHEREAS, SBA and Horizon desire to enter into this MSA which will establish
the general terms and conditions whereby SBA will lease to Horizon space on each
of the Towers and lease or sublease ground space on land in the vicinity of each
of the Towers  conveyed  by Horizon to SBA  pursuant  to the APA (real  property
owned or leased by SBA with respect to each Site (as defined  below)),  together
with  any  and  all  easements  required  for  access  and  utilities  or  other
appurtenances  (hereinafter  referred to as a "Property" and collectively as the
"Properties);

     WHEREAS,  SBA and Horizon have  executed  that certain  Master Design Build
Agreement  ("BTS  Agreement")  contemporaneously  with the execution of this MSA
which provides for the design,  development and  construction of new tower sites
("BTS Sites");

     WHEREAS,  SBA and Horizon have agreed that in the event that Horizon issues
to SBA  Search  Rings  in  Region  2, as  those  terms  are  defined  in the BTS
Agreement,  then Horizon shall have the obligation to lease space on twenty (20)
existing towers owned by SBA in Region 2;

     WHEREAS,  this MSA  shall  govern  the sites  conveyed  by  Horizon  to SBA
pursuant to the APA  ("Conveyed  Sites") and which are developed by SBA pursuant
to the BTS  Agreement  ("BTS  Sites") and which are  already  owned by SBA ("SBA
Sites")  provided (as  hereinafter  defined) that certain  terms,  covenants and
conditions of this MSA may vary, dependent upon whether the Site was conveyed by
Horizon to SBA  pursuant to the APA,  is  developed  by SBA  pursuant to the BTS
Agreement, or is already owned by SBA; and

     WHEREAS,  SBA and Horizon will enter into a Site  Agreement  ("SLA")  which
will  establish  the terms for use of  Conveyed  Sites and BTS Sites in form and
substance  substantially  similar  to  Attachment  "A"  attached  hereto  and by
reference made a part hereof;



                                       1
<PAGE>

     NOW,  THEREFORE,  for good and  valuable  consideration,  the  receipt  and
sufficiency of which are hereby acknowledged,  the parties hereto,  intending to
be legally bound hereby, agree as follows:

     1. MSA. This MSA sets forth the general terms and conditions upon which all
Sites shall be leased to Horizon. SBA and Horizon shall execute SLAs in the form
attached  hereto as Attachment  "A" for each Site conveyed by Horizon to SBA and
by  reference  made a part  hereof at the  closing  anticipated  by the APA with
respect to the  Conveyed  Sites.  SBA and Horizon  shall also execute an SLA for
each BTS Site in accordance  with the provisions of paragraph  2.7(b) of the BTS
Agreement  as such  Sites  arc  identified  from  time to time.  Each SLA  shall
identify a particular Site, as that term is defined below,  made subject to this
MSA. In the event of a conflict or  inconsistency  between the terms of this MSA
and a SLA, the terms of the SLA shall govern and control for that Site.

     2. Site.

          (a) Subject to the following terms and  conditions,  SBA hereby grants
Horizon  the  right  to  install,   maintain  and  operate  Horizon's   wireless
communications  equipment  and  appurtenances  on  space on the  Tower  which is
adequate to allow the installation of the Equipment,  as that term is defined in
this paragraph 2, with sufficient  separation from the equipment owned by SBA or
any  equipment  which is owned or operated by a sublessee  or licensee of SBA as
may be  necessary  to prevent  interference  with the  Equipment  as provided in
paragraph 6 of this MSA ("Tower Space") together with ground space that will not
exceed two hundred fifty (250) square feet on each Property as described in this
paragraph  2  ("Ground  Space")  with  non-exclusive  easements  for  access and
utilities to the Ground Space (collectively the "Easement").  Horizon shall have
exclusive  control and dominion of the Tower Space and the Ground Space provided
that SBA and other tenants of the Property shall have a non-exclusive, temporary
construction  easement over the Site, as that term is hereinafter defined, as is
reasonable  and  necessary  for the  maintenance,  repair  and  installation  of
equipment on the Tower,  but in no event may SBA or any other entity  disturb or
interfere  with the  operations  conducted by Horizon of the Site in  performing
these  activities.  In  no  event  shall  SBA  install  or  allow  its  lessees,
sublessees,  licensees or other  entities  which are granted the right by SBA to
occupy the Property to install any  improvements  below,  on or above the Ground
Space. The Tower Space,  Ground Space,  Easements and Cable Path (as hereinafter
defined) as to any Property may be collectively referred to herein as a "Site."

          (b) Subject to the terms and conditions of this MSA, SBA hereby agrees
to lease each of the Sites to Horizon. SBA further grants and assigns to Horizon
the  non-exclusive  rights:  (i) to utilize portions of any utility Easement for
the  installation and maintenance of utilities,  cables,  conduits and pipes for
the  providing of necessary  utility  service  (including,  without  limitation,
electrical  and  telecommunications  service) to the Equipment  (as  hereinafter
defined);  (ii) to  utilize  the  Property  including  any  ingress  and  egress
easements for pedestrian and vehicular access to and from the Site; and (iii) to
use a  portion  of the  ground  and space on the Tower to  install  cabling  and


                                       2
<PAGE>

utilities for  connecting and linking the Tower Space with the Ground Space (the
"Cable Path"). Horizon shall be entitled to enter the Site on a twenty-four (24)
hour, seven (7) days per week basis during the SLA Term.  Horizon shall give SBA
verbal notice not less than twenty four hours prior to a scheduled  ascension of
a Tower by Horizon or its agents or contractors.  In the event that Horizon must
ascend a Tower for exigent  circumstances  it shall provide verbal notice of the
ascension  of the  Tower  within  twenty  four  (24)  hours  after the tower was
ascended.

          (c) Subject to  paragraph  2(d) with  respect to the  Conveyed  Sites,
Horizon  shall have the right to maintain,  operate,  replace,  reconfigure  and
upgrade on any given Site any equipment which has been installed on a Site prior
to the Date of this MSA including without  limitation any existing PCS antennas,
microwave dishes and related cabling and equipment mounted on the Towers,  above
and below ground  conduit,  RBS  cabinets  and related  equipment on the ground,
cabinetry  and shelters for the  microwave  facilities  and related  cabling and
equipment  on the ground  ("Grandfathered  Equipment").  Within one  hundred and
eighty  (180) days of the  commencement  date of an SLA,  SBA,  with  reasonable
cooperation from Horizon,  shall compile a list of the  Grandfathered  Equipment
for each Site,  which list shall be reviewed and approved by Horizon.  SBA shall
provide Horizon copies of any documentation  including  photographs  relating to
the  Grandfathered  Equipment  in each  medium  in  which  this  information  is
maintained by SBA, including paper and electronic formats.

          (d)  Horizon  shall  have the  right  without  paying  any  additional
consideration to SBA, to install,  maintain,  operate, replace,  reconfigure and
upgrade  the  following  equipment  on each  Site:  (i) one (1) six foot  (6'0")
maximum  diameter  microwave  dish in  addition  to any  other  dishes  or other
microwave equipment which are included in the Grandfathered  Equipment;  (ii) up
to twelve  (12) panel  antennas  (including  any  Grandfathered  Equipment)  and
associated tower top amplifiers and connection boxes,  jumper cabling and twelve
(12) - 1 5/8" coaxial  cables;  and (iii) a generator and a generator  fuel tank
(including any Grandfathered  Equipment)  provided that Horizon shall obtain any
governmental  permits and approvals which are required for such activities.  SBA
acknowledges  and agrees that the  microwave  dish  installed  by Horizon on the
Tower need not be located  within the Tower Space,  provided that in such event,
Horizon  shall  locate the  microwave  dish on the Tower so as not to  adversely
affect the installation of another carrier's equipment on the Tower and to avoid
overloading the Tower when  considering the loads in existence as of the date of
installation  of the microwave dish. In the event that one or more of the Towers
conveyed by Horizon to SBA pursuant to the APA lack adequate  vertical  space or
structural or  windloading  capacity to accommodate a minimum of two (2) tenants
(each  utilizing a standard 12 panel broadband PCS array) in addition to Horizon
(taking into account the Grandfathered  Equipment only),  Horizon shall not have
the right to add additional equipment or reconfigure  Grandfathered Equipment to
any such Tower in such a manner that the  reconfigured  or additional  equipment
would place a greater  structural or windloading  burden on the Tower. SBA shall
have no obligation  with regard to such Conveyed Sites to reinforce,  upgrade or
replace the structure to accommodate the Equipment.  However,  in the event that
SBA chooses to replace a Tower on a Conveyed  Site, it shall be designed to have
adequate structural and wind loading capacity to accommodate the Equipment.



                                       3
<PAGE>

          (e)  Horizon  shall  have the  right  without  paying  any  additional
consideration to SBA, to install  maintain,  operate,  replace,  reconfigure and
upgrade on each Site any  Equipment  which may be located  within  Ground  Space
which will not exceed two hundred  fifty (250)  square  feet.  In  addition,  if
necessary to handle maximum traffic capacity,  Horizon shall also have the right
without  paying any  additional  consideration  to SBA,  to  install,  maintain,
operate,  replace,  reconfigure and upgrade on each Site  additional  electronic
equipment and related cabinetry within the Ground Space.

          (f) The Grandfathered  Equipment and the equipment and items specified
in paragraphs 2(c) and 2(d) shall  hereafter be referred to as the  "Equipment."
In no event shall  Horizon be required  to share the  Equipment  with SBA or any
other  occupant of a Site as a common  facility.  Horizon shall  maintain at its
expense the Equipment in accordance with applicable laws, codes,  ordinances and
regulations.

          (g)  Horizon  may  from  time to time  during  the SLA  Term  replace,
substitute  or  modify  any of the  Equipment.  Horizon  must  submit  plans and
specifications  of the  replacement  modification,  substitution  or  additional
equipment.  SBA shall have the right to cause an intermodulation study, but only
if the  Equipment  is  operating  at a New  Spectrum  as that term is defined in
paragraph  6(a).  SBA shall have the right to cause a structural  analysis to be
performed  using  such  plans and  specifications,  at  Horizon's  sole cost and
expense  but only in the event there  exists a  reasonable  likelihood  that the
windloading  or  structural  capacity  of the load  created by the  replacement,
modification,  substitution or additional equipment exceeds the loads created by
a full array of the Equipment when considering both the type, size and weight of
the antenna and  cabling  which is in use as of the Date of this MSA.  The plans
and  specifications  will be subject to SBA's approval,  such approval not to be
unreasonably   withheld,   delayed  or  conditioned.   The  costs  of  any  such
intermodulation  study or structural  analysis shall not exceed the market rates
for said  services.  It will be  unreasonable  for SBA to reject  such plans and
specifications if the equipment described in the plans (i) does not increase the
wind load or  structural  burden upon the Site above that which would be created
by a full array of the Equipment when considering both the type, size and weight
of the antenna and cabling which is in use as of the Date of this MSA, (ii) does
not  increase the leased  Tower or ground  space,  and (iii) does not create any
technical or radio frequency interference which interferes with the equipment or
network of other users who are then located upon the Site.

          (h) SBA shall not enter into any lease, sublease, license or other
occupancy  agreement (or any amendment or  modification  thereof)  affecting the
Property or the Tower or permit the  installation  of any  equipment  that would
have the effect of (i)  restricting or impairing  Horizon's right to install and
use at any time  during  the SLA Term the full  amount  of the  Equipment;  (ii)
violating any federal,  state or local law,  regulation or ordinances;  or (iii)
impairing  Horizon's access to the Equipment.  In connection with the foregoing,
SBA shall require any structural report or analysis obtained by SBA or any other
proposed  sublessee,  licensee  or other  occupant  of the Tower to  assume  and
incorporate  the  utilization of the full amount of the Equipment  regardless of
whether the full amount of the  Equipment  has been  installed as of the date of
the report or analysis.  In the event of a violation of this Paragraph 2(h) that
is not cured within  thirty (30) days after SBA's  receipt of written  notice of


                                       4
<PAGE>
                                        [***] - CONFIDENTIAL TREATMENT REQUESTED

such  violation,  Horizon may (without being  obligated to do so and in addition
to, and not in lieu of any other remedy available to Horizon on account thereof)
seek  the  enforcement  of this  Paragraph  2(h)  against  SBA  and  any  entity
participating in such violation, including the seeking of equitable relief.

          (i) The Equipment  shall remain the exclusive  property of Horizon and
Horizon  shall have the right to remove all or any portion of the  Equipment  at
any time during the SLA Term.  Horizon shall remove the Equipment  from the Site
within thirty (30) days after the  expiration or any earlier  termination of any
SLA  subject to any rights that SBA may have in and to certain  alterations  and
improvements  to the Site as set forth in this MSA.  Horizon  shall  repair  any
damage  caused by such  removal.  In the event that  Horizon does not remove its
Equipment from a Site on or before the expiration or earlier  termination of the
applicable SLA, then Horizon shall pay as hold-over  rental for the period after
the date of the  termination  or  earlier  expiration  of the SLA a sum which is
equivalent to [***] of the rental rate which was accruing  immediately  prior to
the  expiration  or  termination  of the  applicable  SLA which  amount shall be
prorated through the date that the Equipment is removed from the Site.

          (j) Horizon and its employees,  agents,  consultants  and  contractors
shall be entitled to enter upon the Property for purposes of accessing  the Site
subject to the notice requirements of paragraph 2(b) of this MSA. SBA shall have
the  right  to  approve  those  contractors   engaged  by  Horizon  before  said
contractors  enter a Site  provided  that the approval of any  contractor by SBA
shall not be  conditioned or  unreasonably  withheld or delayed by SBA and, once
such an approval has been given,  shall apply to all Sites which are governed by
this MSA.

     3. Term.

          (a) MSA  Term.  The MSA term  shall  begin on the date of this MSA and
shall continue until the expiration or earlier termination of the last SLA which
remains subject to the terms of this MSA (the "MSA Term").

          (b) SLA Term and Renewal.  Subject to Paragraphs  3(c) and (d) of this
MSA, the initial term of each SLA for  Conveyed  Sites (the  "Initial SLA Term")
shall be [***],  which term  shall  begin on the date set forth in each such SLA
which shall be the Closing  Date as that term is defined in the APA.  Subject to
Paragraphs  3(c) and (d) of this MSA, the Initial SLA Term for BTS Sites and SBA
Sites shall be [***], which term shall begin on the earlier of the date which is
(i) [***] after the date that SBA  notifies  Horizon  that the Tower is suitable
for the  installation  of the  Equipment  or (ii)  the  date  at  which  Horizon
commences  the  installation  of the  Equipment.  The date upon  which  each SLA
commences for any Conveyed Site or BTS Site and each Antenna Site  Agreement (as
hereinafter  defined) for any SBA Site,  may  hereinafter  be referred to as the
"SLA  Commencement  Date."  The  Initial  SLA  Term,  together  with any and all
renewals and extensions thereof, shall be defined as the "SLA Term."

          (c) Subject to Paragraph  3(d) hereof,  without regard to whether such
rights  are or are not set  forth  in each SLA or  Antenna  Site  Agreement  and
further  provided  that  Horizon is not in default in the payment of Rent beyond


                                       5
<PAGE>
                                        [***] - CONFIDENTIAL TREATMENT REQUESTED

any applicable  cure period at the date of the  commencement of the Renewal Term
(as hereinafter  defined),  Horizon shall have the right but not the obligation,
to extend any SLA or Antenna Site Agreement,  [***],  additional  [***] (each, a
"Renewal Term").  Horizon's  sublease of the Site during each Renewal Term shall
be on the same terms and  conditions  as set forth herein except with respect to
rent and insurance as otherwise set forth herein. This MSA and each SLA and each
Antenna Site Agreement shall  automatically  renew for each  successive  Renewal
Term unless Horizon notifies SBA in writing of Horizon's  intention not to renew
any such SLA or Antenna  Site  Agreement  at least  sixty (60) days prior to the
expiration of the Initial SLA Term or the Renewal Term then in effect.

          (d) SBA hereby  covenants  and agrees that, so long as Horizon has not
exercised  its option to refrain from  renewing an SLA,  SBA shall  exercise any
right to renew the  Ground  Lease  (or  refrain  from  effecting  a  non-renewal
thereof,  as the case may be) applicable to such Site and shall not exercise any
right of  termination  of such Ground Lease (except as otherwise  provided under
this MSA) so that such  Ground  Lease  shall  continue  in full force and effect
during the Initial Term and all Renewal Terms available under such SLA.  Without
in any way  modifying  SBA's  obligation to renew each Ground Lease as described
above,  the SLA Term of any SLA shall not extend beyond the term  (including any
renewals   thereof)  of  the  Ground   Lease   applicable   to  such  Site  and,
simultaneously with the expiration or earlier termination of the Ground Lease in
accordance with its terms,  the applicable SLA shall also  terminate;  provided,
however,  that the foregoing shall not be deemed or construed to modify or limit
any of Horizon's rights of  nondisturbance or of cure under such Ground Lease or
under any other  agreement  with the lessor  under such  Ground  Lease  ("Ground
Lessor").  In the event that SBA and the Ground Lessor  hereafter enter into any
further  extensions or renewals of the Ground Lease,  SBA shall provide  written
notice thereof to Horizon within thirty (30) days of the execution thereof.

     4. Rent.

          (a) Sites; Initial Term and Renewal Term For Conveyed Sites.

                    (i)  During the  Initial  SLA Term of any SLA for a Conveyed
          Site,  Horizon  shall pay as annual rent for each SLA at such place as
          SBA may  specify in  writing  to Horizon  from time to time the sum of
          [***] in equal monthly  installments in the amount of [***] per month,
          in advance ("Rent").  The first monthly payment for each Site shall be
          due on the SLA  Commencement  Date for such Site. Rent for any partial
          month during the SLA Term or any renewal or extension thereof shall be
          prorated  and payable  according  to the actual  number of days in the
          calendar month for which such determination of Rent is to be made.

               (ii) On the third  anniversary of the SLA  Commencement  Date for
          each Conveyed Site and on each  anniversary of the  Commencement  Date
          for said Sites thereafter  throughout the Initial Term and any Renewal



                                       6
<PAGE>
                                        [***] - CONFIDENTIAL TREATMENT REQUESTED

          Term,  [***]  which  shall be  identified  by the  parties  by  mutual
          agreement  and by three  percent of the Rent  during  the  immediately
          prior year on the remaining [***] Conveyed Sites governed by this MSA.

          (b) Sites; Initial Term and Renewal Term For BTS Sites in Region 1.

               (i)  During  the  Initial  SLA  Term of any SLA for a BTS Site in
          Region 1 (for  purposes of this MSA,  Region 1 shall mean BTAs 23, 39,
          73, 78, 80, 126, 143, 155, 197, 233, 255, 280, 294, 342, 359, 424, and
          487 and any counties which are adjacent to these BTAs),  Horizon shall
          pay  annual  rent  for each SLA at such  place as SBA may  specify  in
          writing to Horizon from time to time the sum of [***] in equal monthly
          installments  in the amount of [***] per month,  in advance  ("Rent").
          The  first  monthly  payment  for  each  Site  shall be due on the SLA
          Commencement Date for such Site. Rent for any partial month during the
          SLA Term or any renewal or  extension  thereof  shall be prorated  and
          payable  according to the actual number of days in the calendar  month
          for which such determination of Rent is to be made.

               (ii)  Rent  Escalation.  On the  third  anniversary  of  the  SLA
          Commencement  Date  for  each  BTS  Site  in  Region  1,  and on  each
          anniversary  of  the  Commencement  Date  for  said  Sites  thereafter
          throughout  the  Initial  Term and any  Renewal  Term,  Rent  shall be
          increased by [***] of the Rent payable  during the  immediately  prior
          year.

          (c) Sites; Initial Term and Renewal Term For BTS Sites in Region 2.

               (i)  During  the  Initial  SLA  Term of any SLA for a BTS Site in
          Region 2 (for  purposes  of this  MSA,  Region 2 shall  mean BTA 229),
          Horizon  shall pay  annual  rent for each SLA at such place as SBA may
          specify in  writing  to Horizon  from time to time the sum of [***] in
          equal  monthly  installments  in the  amount  of [***] per  month,  in
          advance ("Rent"). The first monthly payment for each Site shall be due
          on the SLA Commencement Date for such Site. Rent for any partial month
          during  the SLA Term or any  renewal  or  extension  thereof  shall be
          prorated  and payable  according  to the actual  number of days in the
          calendar month for which such determination of Rent is to be made.

               (ii)  Rent  Escalation.  On the  first  anniversary  of  the  SLA
          Commencement  Date  for  each  SBA  Site  in  Region  2,  and on  each
          anniversary  of  the  Commencement  Date  for  said  Sites  thereafter
          throughout  the  Initial  Term and any  Renewal  Term,  Rent  shall be
          increased by [***] of the Rent payable  during the  immediately  prior
          year.



                                       7
<PAGE>
                                        [***] - CONFIDENTIAL TREATMENT REQUESTED


          (d) Sites; Initial Term and Renewal Term For SBA Sites.

               (i) In the  event  that  Horizon  issues to SBA  Search  Rings in
          Region 2, as defined in the BTS Agreement, then Horizon shall have the
          obligation  to enter into Antenna  Site  Agreements  (as  described in
          Paragraph  4(d)(iii))  for 20 SBA  Sites in Region 2 within 30 days of
          the  issuance  of such  Search  Ring.  During the first year of a term
          under  the  Antenna  Site  Agreement  for these 20 SBA  Sites,  [***].
          Thereafter,  Horizon  shall pay  annual  rent for each of these 20 SBA
          Sites at such place as SBA may specify in writing to Horizon from time
          to time the sum of [***] in equal monthly  installments  in the amount
          of [***] per month, in advance ("Rent"). The first monthly payment for
          each  Site  shall  be  due  on  the  first   anniversary  of  the  SLA
          Commencement Date for such Site. Rent for any partial month during the
          term or any renewal or extension thereof shall be prorated and payable
          according to the actual number of days in the calendar month for which
          such determination of Rent is to be made.

               (ii)  Rent  Escalation.  On the  first  anniversary  of  the  SLA
          Commencement  Date for each such SBA Site, and on each  anniversary of
          the commencement date for said Sites thereafter throughout the initial
          term and any renewal  term,  Rent shall be  increased  by [***] of the
          Rent payable during the immediately prior year.

               (iii) Antenna Site Lease  Agreement.  Horizon and SBA acknowledge
          and agree  that  this MSA  shall not apply to the SBA Sites  except as
          provided in this paragraph 4(d). SBA and Horizon agree that they shall
          execute the form of Antenna Site Lease  Agreement  attached  hereto as
          Attachment  "B"  for  each  of the 20 SBA  Sites  within  30  days  of
          Horizon's issuance of the first Search Ring in Region 2 to SBA.

          (e) Horizon shall have the right to use a direct  deposit  system with
regard to Rent  payments.  SBA agrees to  cooperate  with  Horizon in  providing
requisite  information to Horizon for such direct deposit. The implementation of
the direct deposit process shall be at Horizon's expense.

     5.  Permitted  Use.  Horizon may use each Site for:  (i) the  transmission,
relay and receipt of communication  signals utilizing any lawful frequencies via
the  Equipment,  (ii)  the  construction,   alteration,   maintenance,   repair,
replacement  and  relocation of the  Equipment in accordance  with the terms and
provisions  of this MSA and  (iii)  any  other  incidental  lawful  purposes  in
accordance with the terms and conditions hereof.

     6. Interference.

          (a)  Horizon's  use of  each  Site as  permitted  in  accordance  with
Paragraph 5 for the installation  and operation of the Equipment  (including any
microwave  dishes  installed and operated by Horizon pursuant to Paragraph 2(d))
shall constitute the "Senior Use" on the Property.  The Senior Use shall further


                                       8
<PAGE>

include any use or uses by substitute, modified or replacement antennas that are
installed within the Tower Space on account of damage, disrepair or obsolescence
of any of the  antennas  described  above or failure of such  antennas  to yield
optimum performance,  even if such substitute,  modified or replacement antennas
are of a  different  model or  manufacturer.  Horizon's  use of the Site for the
Senior Use shall be deemed for all  purposes the  senior-in-priority  use of the
Property.  It is  understood  that should the Equipment  operate at  frequencies
different from the frequencies than those which Horizon has authority to utilize
("New Spectrum") as of the Date of this MSA, the use of those  frequencies shall
not be a Senior Use for the  purpose  of  resolving  interference  with the then
existing  uses at that Site.  Notwithstanding  the  foregoing,  if Horizon shall
begin the operation of  frequencies  pursuant to a New Spectrum,  the use of the
New Spectrum shall thereafter constitute a Senior Use relative to any use of the
Property  which  commences  after  the  date of  commencement  of use of the New
Spectrum.  If the  equipment  which  is  operating  at the New  Spectrum  causes
interference  with  the  then  existing  equipment  at  the  Property  and  such
interference cannot be eliminated within five (5) business days after receipt by
Horizon of notice from SBA of the existence of interference, Horizon shall cease
the  operation  of the  Equipment  which is operating at the New Spectrum and is
causing  interference  (except  for  intermittent  operation  for the purpose of
testing, after performing maintenance,  repair,  modification,  replacement,  or
other action taken for the purpose of correcting such  interference)  until such
interference is corrected.

          (b) In the event that, as to any Site leased to Horizon pursuant to an
SLA, SBA enters into any lease, sublease or license agreement in the future with
any third party for other portions of the Property or the Tower, then SBA agrees
to require such lessee,  sublessee or licensee to install equipment of types and
operating at radio  frequencies  that will not cause  interference  to Horizon's
communications  operations being conducted from the Site. SBA agrees that in the
event such lessee, sublessee or licensee causes interference with the Equipment,
SBA will  require  such  sublessee  or licensee to take all steps  necessary  to
correct and eliminate the interference.  SBA will notify such lessee,  sublessee
or licensee of such interference  within 24 hours of receipt of such notice from
Horizon. If such interference cannot be eliminated within five (5) business days
after receipt by such  sublessee or licensee of notice from SBA of the existence
of  interference,  SBA  shall  cause  such  lessee,  sublessee  or  licensee  to
disconnect  the  electric  power  and shut down such  lessee's,  sublessee's  or
licensee's  equipment  (except  for  intermittent  operation  for the purpose of
testing,  after performing  maintenance,  repair,  modification,  replacement or
other action taken for the purpose of correcting such  interference)  until such
interference is corrected.  If such interference is not completely  rectified to
the satisfaction of Horizon within sixty (60) days after receipt by such lessee,
sublessee  or licensee of such  notice  from SBA,  SBA shall cause such  lessee,
sublessee or licensee to remove its antennas and equipment from the Property and
the Tower.

          (c)  Pursuant  to the  APA,  SBA has  assumed  leases,  subleases  and
licenses of the Property  and the Tower with respect to the Conveyed  Sites from
Horizon which contain covenants against interference and certain other covenants
relating  to  Horizon's  Senior Use of the Site.  SBA hereby  agrees to take all
reasonable  means necessary to enforce such covenants for the benefit of Horizon
upon Horizon's reasonable request, including without limitation the commencement
of appropriate legal actions or proceedings.



                                       9
<PAGE>

                                        [***] - CONFIDENTIAL TREATMENT REQUESTED

     7. Utilities.

          (a) Use by Horizon.  Horizon shall pay the cost of all electric power,
telephone  and other  utility  service  consumed  by  Horizon in  operating  the
Equipment  and shall make payment  therefor  when due directly to the  providing
utility or service  company before any lien,  fine,  penalty,  interest or other
charge may attach on account of nonpayment.

          (b) Use by SBA and  Others.  Except  for the cost of  electric  power,
telephone  and other  utility  service  consumed  by  Horizon in  operating  the
Equipment,  SBA  shall  pay or cause to be paid  the cost of all  utilities  and
services  utilized on the Property  directly to the providing utility or service
company before any lien, fine,  penalty,  interest or other charge may attach on
account  of  nonpayment.  SBA shall  not nor  shall it allow any third  party to
sub-meter  electricity at any Site from Horizon. SBA and any third party granted
a right to use the Property or a portion thereof in accordance with the terms of
this MSA may connect to the utility  improvements  which serve the Site provided
that said utilities  shall (i) be separately  metered from Horizon's  utilities,
(ii) not cause an undue  loading on the  electrical  service  when  taking  into
consideration the electrical load created by the Equipment which has been or may
be installed at the Site by Horizon and (iii) be insured on the  secondary  side
of the utility transformer which provides electrical service to the Site.

     8. Ground Lease Default:  Horizon's Right to Cure. Upon the occurrence of a
Monetary  or  Non-Monetary   Ground  Lease  Default,   as  hereinafter   defined
(collectively,  "Ground Lease  Defaults")  and without  limiting or  restricting
Horizon's rights or remedies under Paragraphs 9, 10 and 11 hereof, Horizon shall
be authorized to exercise the remedies set forth below in this Paragraph 8:

          (a) In the case of a default in the payment of rent due under a Ground
Lease or a default in any other obligation  imposed upon SBA as lessee under the
Ground  Lease the cure of which can be reduced to the payment of a monetary  sum
(a "Monetary Ground Lease Default"),  Horizon may, within or outside of any cure
period provided therefor in the Ground Lease or otherwise afforded to Horizon by
an  agreement  with the  Ground  Lessor,  pay to the  Ground  Lessor  any amount
required  under the Ground  Lease to cure such  default so that the Ground Lease
shall  remain in full  force and  effect,  including,  without  limitation,  any
interest,  late charge or other assessment  charged or assessed by Ground Lessor
with respect thereto. Horizon shall provide to SBA written notice of such action
at or before the time of making the foregoing payment to the Ground Lessor.  SBA
shall  have a period of ten (10) days from the date of  receipt  of said  notice
from Horizon to cure said default  before Horizon may affect a cure pursuant and
demand an offset  against Rent  pursuant to this  paragraph.  Following any such
payment by Horizon to Ground  Lessor,  Horizon shall be entitled to withhold the
full amount thereof,  plus an additional  administrative  charge of [***] of the
amount paid, from  installments of Rent next owing under any such SLA until such
amount and charge have been fully credited. In connection therewith, the parties
hereby acknowledge that such  administrative  charges are intended to compensate
Horizon for its administrative and additional overhead costs, fees


                                       10
<PAGE>

and expenses  reasonably  anticipated and estimated to be incurred on account of
such action and are not intended to be imposed as a penalty.

          (b) In the case of a  default  under a Ground  Lease the cure of which
cannot be reduced to the payment of a monetary sum  ("Non-Monetary  Ground Lease
Default"), Horizon may, upon written notice to SBA (except in cases of emergency
whereby  Horizon  shall  provide  such notice as promptly as possible  after the
fact),  commence and prosecute  any and all action or actions  necessary to cure
such default as may be available to SBA under the terms and  conditions  of such
Ground Lease.  SBA shall have a period of ten (10) days from the date of receipt
of said notice from  Horizon to cure said  default  before  Horizon may affect a
cure pursuant and demand an offset against Rent pursuant to this  paragraph.  In
the event of any such  curative  action by Horizon  described in this  Paragraph
8(b),  Horizon  shall be entitled  to withhold  the full amount of all costs and
expenses  incurred  by  Horizon in  completing  such  cure,  plus an  additional
administrative  charge of five percent (5%) of such amount, from installments of
Rent next  owing  under this MSA until  such  amount and charge  have been fully
credited.

          (c) In the event that  Horizon  effects a cure of a breach of a Ground
Lease by SBA as provided  herein,  Horizon may, at its election,  require SBA to
assign the Ground  Lease to Horizon  and effect an  Acquisition  pursuant to the
terms of paragraph 9 hereof.

     9. Other Defaults by SBA; Additional Horizon Remedies.

          (a) The following shall constitute  events of default under the MSA by
SBA:

               (i) Breach of any representation,  warranty or covenant set forth
          in this Agreement  including the applicable SLA (with the exception of
          the  interference  provisions  set forth in  Paragraph 6) which is not
          cured within  thirty (30) days of receipt of written  notice,  or such
          shorter time as may be specified by this MSA or the applicable  Ground
          Lease,  except  such  cure  period  will  be  extended  as  reasonably
          necessary to permit SBA to complete the cure so long as SBA  commences
          the cure  within such  thirty  (30) day  period,  or other  applicable
          period,  and  thereafter   continuously  and  diligently  pursues  and
          completes such cure;

               (ii) If any  petition  is  filed by or  against  SBA,  under  any
          paragraph or chapter of the present or any future  federal  Bankruptcy
          Code or under any similar  law or statute of the United  States or any
          state  thereof (and with respect to any  petition  filed  against SBA,
          such  petition  is not  dismissed  within  ninety  (90) days after the
          filing  thereof),  or SBA is adjudged  bankrupt in  proceedings  filed
          under any paragraph or chapter of the present or any future Bankruptcy
          Code or under any similar  law or statute of the United  States or any
          state thereof;

               (iii) If a receiver, custodian or trustee is appointed for SBA or
          for substantially all of the assets of SBA and such appointment is not
          vacated within sixty (60) days of the date of appointment; or



                                       11
<PAGE>

               (iv) If SBA makes a transfer in fraud of creditors.

          (b) Upon the  occurrence  of any  default by SBA under this MSA or any
Ground Lease  Default,  Horizon shall be entitled to exercise any one or more of
the following  rights or remedies in accordance with, and subject to, the terms,
provisions and conditions of this MSA:

               (i) in the case of a default  of this MSA  resulting  from  SBA's
          failure to renew the Ground  Lease as required  under  Paragraph  3(d)
          hereof,  Horizon  shall  have  the  right to take  all  necessary  and
          appropriate steps to effect a renewal thereof;

               (ii) in the event of a breach  or an  alleged  default  under the
          Ground  Lease by SBA which is not cured  within five (5) days prior to
          the date that period to cure  defaults  under the Ground Lease expires
          or if SBA shall fail to properly  effect a renewal of a Ground  Lease,
          then Horizon may upon written  notice to SBA,  acquire from SBA all of
          SBA's rights,  title,  benefits,  interests and obligations  under the
          applicable Ground Lease (hereinafter  referred to as an "Acquisition")
          in accordance  with the provisions of Paragraphs 9(b) and 9(c) hereof,
          whereupon at the completion of the Closing (as hereinafter defined) of
          such Acquisition the applicable SLA shall terminate;

               (iii) upon written notice to SBA, terminate the applicable SLA(s)
          without  exercising its right of Acquisition,  whereupon Horizon shall
          have no further  liability  to SBA  hereunder  with regard to any such
          SLA(s); and

               (iv) with or without  terminating  the applicable SLA, pursue any
          and all other remedies available  hereunder or under applicable law or
          in equity.

          (b) In the event that Horizon elects to exercise its right to cause an
Acquisition, the SBA Improvements, including, without limitation, the Tower, any
concrete foundation,  and any utilities structure or other improvements owned by
SBA on the  Property  shall be  bargained,  sold and  conveyed  to  Horizon at a
purchase  price  equal  to the fair  market  value  of such  improvements  after
disassembly, less any dismantling and moving expenses and less the amount of any
debt or  obligation  encumbering  or secured by such SBA  Improvements.  Nothing
contained  herein  shall be deemed to grant  SBA the right to  encumber  the SBA
Improvements except as otherwise provided in this MSA.

          (c) The closing of the Acquisition  (the "Closing") shall occur within
thirty (30) days after  SBA's  receipt of  Horizon's  notice of exercise of such
right.  During the  aforementioned  period  prior to Closing,  Horizon  shall be
entitled (but shall not be obligated) to take all measures necessary to maintain
each Ground Lease in full force and effect,  including  the exercise of the cure
remedies  described above in Paragraph 8 hereof;  provided,  however,  that such
right shall not relieve SBA of its primary  responsibilities  in respect of each
Ground Lease. SBA agrees to deliver to Horizon  originals or copies of any other
existing leases,  subleases and licenses affecting the Property. At the Closing,
(i) Horizon shall pay to SBA the purchase price for the SBA  Improvements  to be
conveyed to Horizon  under this  Paragraph 9; (ii) SBA shall execute and deliver
to Horizon a bill of sale without recourse to such SBA  Improvements;  (iii) SBA


                                       12
<PAGE>

and Horizon  shall  execute and deliver an  assignment  and  assumption  without
recourse of each Ground  Lease and of existing  leases,  subleases  and licenses
consistent  with the terms and  conditions  hereof and a  termination  agreement
providing  for  the  termination  of the  applicable  SLA as of the  date of the
Closing; and (iv) any and all other deeds, instruments and other writings as may
be reasonably required by Horizon or its title insurer to effect the Acquisition
or procure title insurance to the Property.

          (d) SBA shall indemnify and hold Horizon harmless from and against any
claims,  actions,  injuries,  losses or damages (including reasonable attorneys'
fees and court  costs)  suffered  or  incurred  by  Horizon  on account of SBA's
actions or omissions  under or with respect to the Ground Lease and any assigned
subleases and licenses with any third party prior to the Closing.  Horizon shall
indemnify and hold SBA harmless from and against any claims, actions,  injuries,
losses  or  damages  (including  reasonable  attorneys'  fees and  court  costs)
suffered or incurred by SBA on account of Horizon's  actions or omissions  under
or with respect to the Ground Lease and the assigned subleases and licenses with
any third party after the Closing. The respective obligations of SBA and Horizon
under this Paragraph  9(d) shall survive the Closing and the  termination of the
applicable SLA.

          (e) In no event shall an event of default under one SLA  constitute an
event of default under any other SLA or entitle Horizon to exercise any remedies
in relation to any Site other than the Site which is the subject of the event of
default;  provided,  however,  that  Horizon  shall be entitled to exercise  any
setoff rights it may possess  against SBA,  whether arising under this Agreement
or by operation of law, against any SLA.

     10. Horizon's  Default.  The occurrence of any one or more of the following
events constitutes an "event of default" by Horizon under any SLA.

          (a) If Horizon fails to pay Rent within ten days of Horizon's  receipt
of written request for payment;

          (b) Breach of any  representation,  warranty or covenant  set forth in
this Agreement  including any SLA, with the exception of the  non-payment of any
fee or other sums by  Horizon,  which is not cured  within  thirty  (30) days of
receipt of written  notice or such  shorter time as may be specified by the MSA,
except such thirty (30) day cure period will be extended as reasonably necessary
to permit  Horizon to complete  the cure so long as Horizon  commences  the cure
within such thirty (30) day period and  thereafter  continuously  and diligently
pursues and completes such cure;

          (c)  If any  petition  is  filed  by or  against  Horizon,  under  any
paragraph  or chapter of the present or any future  federal  Bankruptcy  Code or
under any similar law or statute of the United  States or any state thereof (and
with  respect  to any  petition  filed  against  Horizon  such  petition  is not
dismissed  within  ninety  (90) days  after the filing  thereof),  or Horizon is
adjudged  bankrupt in  proceedings  filed under any  paragraph or chapter of the
present or any future Bankruptcy Code or under any similar law or statute of the
United States or any state thereof;



                                       13
<PAGE>

          (d) If a receiver,  custodian or trustee is  appointed  for Horizon or
for any of the assets of Horizon  and such  appointment  is not  vacated  within
sixty (60) days of the date of appointment or

          (e) If Horizon makes a transfer in fraud of creditors.

     11. SBA's Remedies.  If an event of default by Horizon occurs, SBA (without
notice  or  demand  except  as  expressly  required  above)  may  terminate  the
applicable SLA. Horizon will become liable for damages equal to the total of:

          (a) The actual,  reasonable  costs of recovering  the Site which is in
default, including reasonable attorneys' fees);

          (b) The Rents accrued and payable as of the date of termination,  plus
interest thereon from the date due until paid; and

          (c) the Rent  reserved for the remainder of the then existing SLA Term
as such Rents would ordinarily become due and payable.

          (d) If  Horizon  does not cure an actual  default  within  the  period
available to cure a default,  SBA may cure the default and demand  reimbursement
from Horizon of those reasonable  expenditures  made by Horizon to cure any such
default.  Following  any such  payment by SBA,  SBA shall be  entitled to demand
reimbursement  from  Horizon  of the full  amount  thereof,  plus an  additional
administrative  charge of five percent (5%) of the amount  paid.  In  connection
therewith,  the parties hereby acknowledge that such administrative  charges are
intended to compensate SBA for its administrative and additional overhead costs,
fees and expenses reasonably anticipated and estimated to be incurred on account
of such action and are not intended to be imposed as a penalty.

          (e) In no event shall SBA be entitled  to  accelerate  Rents due under
any SLA. In no event shall an event of default under one SLA constitute an event
of default  under any other SLA or  entitle  SBA to  exercise  any  remedies  in
relation  to any Site other  than the Site which is the  subject of the event of
default  provided,  however,  that SBA shall be entitled to exercise  any setoff
rights it may possess against  Horizon,  whether arising under this Agreement or
by operation of law, against any SLA.

     12. Termination Rights of Horizon.  In addition to, and not in lieu of, any
other  rights  of  termination  set  forth  herein,  Horizon  may on one or more
occasions terminate any SLA without any penalty or further liability as follows:

          (a) during any Renewal  Term upon not less than sixty (60) days' prior
written notice to SBA if,  notwithstanding the exercise of Horizon's reasonable,
diligent and good faith efforts, Horizon is unable to obtain or maintain the FCC
license or other governmental approval or permit required to continue to utilize
the Site in the manner then currently utilized;



                                       14
<PAGE>

          (b) upon not less than thirty (30) days' prior  written  notice to SBA
if,  through no fault of  Horizon,  SBA may no longer  lawfully  operate the SBA
Improvements  as a wireless  communications  facility or may no longer  lawfully
maintain the Tower on the Property;

          (c) upon not less than thirty (30) days' prior  written  notice to SBA
if Horizon  determines,  in its reasonable  discretion  exercised in good faith,
that the  Property has  experienced  or suffered,  or hereafter  experiences  or
suffers,  an environmental  contamination or other hazardous  substance  release
through  no  fault  of  Horizon  that  was  not  disclosed  in an  environmental
assessment  provided to Horizon prior to the execution of the SLA and, for those
Sites  conveyed by Horizon to SBA pursuant to the SBA,  that said  contamination
did not exist as of the date Sites were conveyed;

          (d) upon not less than six (6) months' prior written notice to SBA for
no reason or any reason at all after the expiration of the Initial Term.

          In the event that Horizon  terminates the SLA for any Site pursuant to
this Paragraph 11, Horizon shall, upon such termination, effect a timely removal
of its  Equipment  and  transfer  to SBA all of its right  title  and  interest,
without representation or warranty, to any concrete foundations,  tower mounting
platforms, power poles, utility service entrance equipment,  cabling and conduit
remaining at such Site.

     13. Additional Warranties and Covenants.  So long as this MSA is in effect,
SBA hereby further covenants, warrants and agrees as follows:

          (a) SBA shall not exercise any right of  termination  available to SBA
as the tenant  under any Ground Lease except in a Renewal Term and may only then
exercise a right to terminate  the Ground Lease if SBA  exercises  such right to
protect safety or property or SBA reasonably  believes that continued leasing of
the Site will  cause or has  caused SBA to incur  liability  exceeding  the fair
market value of the Site. SBA may not exercise this termination right unless SBA
gives Horizon at least 30 days' notice. This notice shall give Horizon the right
to cause an Acquisition  of the Site as described in Paragraphs  9(b) and (c) of
this MSA.  Horizon  must accept the offer within ten (10) days of receipt of the
notice.  If SBA fails to  receive a  response  within  the ten (10) day  period,
Horizon will be deemed to have  rejected the offer,  and SBA will have the right
to terminate the Ground Lease. If Horizon accepts the offer, an Acquisition will
occur as described in Paragraphs 9(b) and (c) of this MSA.  Without limiting the
generality  of the  foregoing,  in the event of any  bankruptcy  filing or other
insolvency  proceeding  by or against SBA in which the Ground Lease is rejected,
or sought to be rejected,  by SBA or SBA's  trustee or other  representative  of
SBA's  bankruptcy  estate,  SBA shall  invoke any and all rights under 11 U.S.C.
Section 365(h) or any other applicable provision (or any successor provision) to
continue  SBA's  occupancy of the Property so as to permit  Horizon's  continued
occupancy and use of the Site as authorized herein;

          (b) SBA shall duly and punctually perform each and every obligation of
the  "Lessee"  under (and as defined in) the Ground Lease and shall not cause or
permit  the  occurrence  of any  event of  default  on the part of the  "Lessee"
thereunder;



                                       15
<PAGE>

          (c) SBA shall not surrender, or offer to surrender,  any Property to a
Ground Lessor;

          (d) SBA shall not enter  into any  amendment  of a Ground  Lease  that
would  adversely  affect any right or remedy of Horizon  hereunder  or under the
applicable SLA;

          (e) In the event of Ground  Lessor's  failure  to observe or perform a
warranty or covenant of such Ground  Lessor  under the  applicable  Ground Lease
which  has  an  adverse  affect  upon  Horizon's   permitted  use  or  Horizon's
governmental  permits,  SBA shall use diligent and good faith  efforts to compel
Ground Lessor's observance or performance of such warranty or covenant;

          (f) As promptly  as possible  upon SBA's  receipt  thereof,  SBA shall
provide  to  Horizon a copy of any  notice of  default  received  by SBA under a
Ground Lease; any notice of a bankruptcy,  receivership or other insolvency case
or proceeding affecting a Ground Lease or a Property; and any notice,  complaint
order or decree  affecting,  or  seeking  to affect the status of a Tower or the
operation of a Property as a wireless communications facility. In the event that
SBA  provides to a Ground  Lessor any notice of a default by such Ground  Lessor
under the Ground Lease, SBA shall  simultaneously  provide a copy of such notice
to  Horizon.  SBA will not  terminate  a Ground  Lease due to such  default by a
Ground  Lessor except during a Renewal Term and only then if SBA first offers to
assign such Ground Lease to Horizon, in which event Horizon shall have the right
to take an assignment of the Ground Lease and to cause an  Acquisition.  Horizon
shall provide  notice to SBA of the intent of Horizon to accept an assignment of
a Ground Lease  within ten (10) days of the date that Horizon  receives a notice
of such an event from SBA.  The  failure of Horizon to tender said notice to SBA
within ten (10) days of the date that Horizon receives a notice of such an event
from SBA shall constitute a waiver of Horizon's right to accept an assignment of
the Ground Lease;

          (g) SBA shall not  authorize,  permit or allow any third  party to use
any portion of a Property in violation of applicable laws, regulations, codes or
ordinances  (including,  without  limitation,  any legal requirements  governing
radio frequency emissions) or in violation of the applicable Ground Lease; and

          (h) SBA  shall  maintain  at its  expense  the Tower and any other SBA
Improvements  on  the  Property  in  accordance  with  applicable  laws,  codes,
ordinances and regulations, including any applicable lighting, painting or other
marking  requirements.  In the  event  that  a  Tower  is  subject  to  lighting
requirements under any applicable laws,  ordinances,  codes or regulations,  SBA
shall  maintain an alarm system to monitor the operation of such  lighting,  and
Horizon may install at its expense a tie-in  monitor or alarm to inform  Horizon
of the operation of such lighting. SBA shall indemnify and hold Horizon harmless
from and against any actions, claims, proceedings,  damages, liabilities,  fees,
fines,  expenses and other losses  suffered or incurred by Horizon in connection


                                       16
<PAGE>

with the tower lighting system, except such matters as may have been suffered or
incurred  solely as the result of Horizon's  negligence  or willful  misconduct.
Notwithstanding  the foregoing,  the  maintenance  of the tower lighting  system
shall be the  responsibility  of SBA immediately upon the execution of such SLA.
In the event that Horizon  discovers that one or more lighting systems which are
required by any governmental agency are malfunctioning, Horizon shall notify SBA
at the  following  telephone  number,  which number shall be monitored by SBA 24
hours a day, 7 days a week.  1-888-950-7483 (SITE). Horizon shall be entitled to
take any action which it deems reasonably  necessary,  including  repairing such
lighting system and/or notifying the FAA, FCC or any other  governmental  agency
without any liability  whatsoever to SBA for such actions if SBA fails to follow
the applicable government procedures beyond applicable notice and grace periods.
SBA shall maintain each Tower in good condition and repair.

          (i) SBA does hereby agree to indemnify and hold Horizon  harmless from
any and all losses,  damages,  fines,  penalties  or costs of any kind which may
arise from the  improper  design,  maintenance  or operation of a Tower or tower
lighting systems,  or which may be imposed by the FAA, FCC or any other federal,
state or local agency arising from the improper design, maintenance or operation
of a Tower or tower lighting  systems  unless  arising from  Horizon's  actions.
Should Horizon be cited because a Site is not in compliance  through no fault of
Horizon and, should SBA fail to cure the conditions of noncompliance  within the
time to cure  the  noncompliance  as  required  by the  applicable  governmental
agencies, Horizon may either terminate the applicable SEA or, with prior written
notice from Horizon to SBA and allowing  SBA a reasonable  opportunity  to cure,
proceed to cure the conditions of noncompliance at SBA's expense. Amounts of all
reasonable expenses to cure such conditions of noncompliance,  together with any
such fine or citation paid by Horizon, may be deducted by Horizon from the Rent.

          (j)  If  antenna  power  output  ("RF  Emissions")  are  presently  or
hereafter become subject to any restrictions imposed by the FCC for RF Emissions
standards on Maximum Permissible  Exposure ("MPE"), or if the Tower otherwise is
or becomes subject to federal, state or local rules,  regulations,  restrictions
or  ordinances,   Horizon  shall  comply  with  SBA's  reasonable  requests  for
modifications to Horizon's  Equipment which are reasonably  necessary for SBA to
comply. SBA shall take all measures to ensure that all other lessees, sublessees
and licensees  comply,  with such limits,  rules,  regulations,  restrictions or
ordinances.  The RF Emissions  requirements  of Horizon shall be superior to the
requirements of any other occupants of the Property,  provided,  however that in
no event shall Horizon's RF Emissions exceed any limitations  imposed by the FCC
for the  operation of equipment by a single,  PCS or  comparable  tenant.  If an
engineering  evaluation or other power density study be performed to evaluate RF
Emissions  compliance  with MPE limits is required under  applicable law, SBA or
other lessees shall bear all costs of such an evaluation or study. If said study
indicates that RF Emissions at the facility do not comply with  thelimits,  then
SBA and all of SBA's other lessees,  licensees and sublessees shall  immediately
take any steps necessary to ensure that they are individually in compliance with
such limits and shall cease or reduce operations until a maintenance  program or
other  mitigating  measures  can be  implemented  to comply  with MPE.  At SBA's
request,  Horizon  shall  provide to SBA  technical  data  necessary for routine
calculations of MPE compliance, including, but not limited to, TPO gains, losses
and operating frequencies.

          (k) SBA at its sole cost and  expense,  except if such cost or expense
arises  out of a  negligent  or  wrongful  act or  omission  of  Horizon  or its


                                       17
<PAGE>

contractors, shall monitor, maintain and repair each Tower such that Horizon may
utilize  such  Tower  for the  use  permitted  under  Paragraph  5 of this  MSA,
including, without limitation,  lighting systems and markings and the structural
integrity of each Tower  Installation,  maintenance and repair of the Tower must
comply  with all laws  applied in a manner  consistent  with  standard  industry
practices except for minor noncompliance that do not affect Horizon's fights and
privileges under this MSA.

     14. Relocation.

          (a) Following the date of this MSA,  Horizon shall have the right,  at
Horizon's  sole cost and  expense,  to  relocate  the Tower Space at any Site to
another  location on the Tower (the  "Relocated  Tower  Space"),  provided  that
Horizon must first obtain SBA's prior written consent which consent shall not be
unreasonably conditioned, delayed or withheld.

          (b) Following  any such  relocation,  the Relocated  Tower Space shall
thereafter be deemed the "Tower  Space" for all purposes  under this MSA and the
applicable  SLA,  shall be leased to and occupied by Horizon in accordance  with
the terms and  conditions  of this MSA, and this MSA and the SLA shall be deemed
amended accordingly.  Horizon's  obligations to pay any expense or cost incurred
on account of such relocation shall survive any expiration or sooner termination
of this MSA.

     15.  Financing  Matter.  SBA  hereby  represents,  covenants  and agrees as
follows:

          (a) SBA  shall not  grant,  convey  or cause to  attach  any  security
interest  in, to or  against  any of SBA's  interest  or title  under any of the
Ground Lease,  SBA's interest or title under any SLA, this MSA, any of the Tower
or any of the other SBA Improvements  unless, and this MSA and the SLAs shall be
subordinate  to the  Security  Interest  if the  grantee  or holder  thereof  (a
"Secured  Party") and SBA duly execute and deliver to Horizon a  non-disturbance
and  attornment  agreement  ("NDA")  in a form  substantially  the  same as that
attached hereto as Attachment "C".

          (b) Except for the  attachment  of a Security  Interest  as  permitted
under  Paragraph  15 (a) of this MSA,  SBA shall not at any time during the Term
permit or allow  the  filing or other  attachment  of any lien,  charge or other
encumbrance against the Site, the Property, the Tower, or other SBA Improvements
on account of its work with respect  thereto (other than liens that are inchoate
or otherwise  attach by operation of law and  subsequently  accrue or secure the
payment of a subsequently accruing obligation,  but in all events subject to the
requirement  to  discharge  same as provided in the next  sentence  hereof),  or
otherwise  during the SLA Term on account of SBA's acts or omissions or the acts
or omissions of its  lessees,  sublessees  or  licensees.  Without  limiting the
foregoing, SBA shall discharge of record, whether by bond, payment or otherwise,
any such lien,  charge or encumbrance  prohibited under this Paragraph 15 within
thirty  (30) days  after  receipt of actual  notice of the filing or  attachment
thereof.

          (c) Horizon  shall not at any time during the Term permit or allow the
filing or other  attachment  of any  involuntary  lien,  charge  or  encumbrance
against the  Equipment,  Site, the Property,  the Tower,  any SLA or this MSA on
account of its work with respect  thereto (other than liens that are inchoate or


                                       18
<PAGE>

otherwise  attached by  operation of law and  subsequently  accrue or secure the
payment of the subsequently  accruing  obligation,  but in all events subject to
the requirement to discharge same as provided in the next sentence  hereof),  or
otherwise  during the Term on account of Horizon's  acts or  omissions.  Without
limiting the  foregoing,  Horizon  shall  discharge of record,  whether by bond,
payment or otherwise,  any such lien,  charge,  or encumbrance  prohibited under
this  Paragraph 15 within thirty (30) days after receipt of actual notice of the
filing or attachment thereof.

     16. Casualty and  Condemnation.  If the whole or any substantial  part of a
Site shall be taken by any public authority under the power of eminent domain so
as to interfere with Horizon's use and occupancy  thereof,  then the term of the
applicable  SLA shall  cease on the part so taken on the date of  possession  by
such  authority of that part, and any unearned Rent paid in advance of such date
shall be refunded by SBA to Horizon within thirty (30) days of such  possession,
and Horizon  shall have the right to terminate the  applicable  SLA upon written
notice to SBA,  which notice shall be  delivered by Horizon  within  thirty (30)
days  following  the date  notice  is  received  by  Horizon  of such  taking or
possession.  If Horizon  chooses not to terminate the  applicable  SLA, the Rent
shall be reduced or abated in proportion to the actual reduction or abatement of
Horizon's  use of the  Site.  If all or a  portion  of the  Site  is  destroyed,
rendering the Site unusable,  Rent will be suspended until the Site is restored.
SBA shall have a period of one hundred twenty (120) days to restore the Site. If
the  restoration  is not completed  within one hundred  twenty (120) days,  then
Horizon shall have the right to terminate the applicable SLA.

     17. Taxes.

          (a) Horizon shall pay, on or before the due date thereof, all personal
property  taxes levied  against the Equipment  and all taxes levied  against the
Rent  except  for income  taxes  payable by SBA.  If the  assessed  value of the
Property is increased by  inclusion of the  Equipment  and SBA is liable for the
payment of such increase in taxes,  then Horizon shall pay to SBA, within thirty
(30) days after receiving a written request for payment or at least fifteen (15)
days prior to the due date of such taxes (whichever is later),  the part of such
increase in taxes  specifically  attributable to the inclusion of the Equipment.
As a condition of such payment, SBA shall provide to Horizon an original or copy
of the tax assessment or other taxing  authority  documentation  evidencing such
increase on account of the Equipment.

          (b) SBA  shall  pay or  cause to be paid,  on or  before  the due date
thereof,  personal  property taxes levied against the Tower and SBA Improvements
and all real  property  taxes for which SBA is liable  under the Ground Lease or
applicable law.

     18. Insurance and Subrogation.

          (a) SBA and Horizon  shall each provide and  maintain  during the Term
commercial  general  liability  insurance in an aggregate  amount of Two Million
Dollars  ($2,000,000)  per site and name the other party hereto as an additional
insured on such policy or policies.  Each party may satisfy this  requirement by
obtaining  appropriate  endorsements to any master policy of liability insurance


                                       19
<PAGE>

maintained by such party. In no event shall the deductible  under either party's
policy of commercial general liability  insurance exceed Ten Thousand and No/100
Dollars  ($10,000.00).  Without  limiting the  generality  of SBA's  covenant to
comply with the obligations of the Ground Lease, SBA agrees that with respect to
the Conveyed  Sites it shall maintain  during the Term insurance  required to be
maintained by "Horizon"  under the Ground Lease.  The policy amount set forth in
this  Paragraph  18(a) shall be reset on every fifth  anniversary of the Date of
this MSA to increase by a commercially  reasonable amount but not more than 115%
of the policy amount set during the preceding five (5) year period.  The parties
shall also  maintain any other  insurance  required by law,  including  workers'
compensation insurance.

          (b) To the  extent  permitted  under  both of the  parties'  insurance
policies,  neither  party  shall  be  liable  to the  other  (or to the  other's
successors or assigns) for any loss or damage caused by fire or any of the risks
enumerated in a standard "All Risk" insurance policy,  and, in the event of such
insured loss,  neither party's  insurance  company shall have a subrogated claim
against the other. To the extent permitted under both of the parties'  insurance
policies each party hereto shall obtain from its insurers  under all policies of
fire, theft and other casualty insurance maintained by it at any time during the
Term  insuring or covering  the  Property or the Site,  or any portion  thereof,
improvements   thereon  or  operations  therein,  a  waiver  of  all  rights  of
subrogation which the insurer might have against the other party.

          (c)  During  the  Initial  Term and any  Renewal  Term of any SLA on a
particular  Site,  SBA shall  maintain an  all-risks  policy of property  damage
insurance on such Site which contains or provides for replacement  cost coverage
is  sufficient  in  amount  to  rebuild  and  replace  the  Tower  and other SBA
Improvements in the event of any casualty loss.  During the Initial Term and any
Renewal  Term  of any  SLA on a  particular  Site,  Horizon  shall  maintain  an
all-risks  policy of property  damage  insurance on such Site which  contains or
provides for  replacement  cost  coverage is sufficient in amount to rebuild and
replace the Equipment in the event of any casualty loss.

     19. Indemnifications.

          (a) Subject to Paragraph 18(b) above, Horizon shall indemnify,  defend
and hold SBA  harmless  from  and  against  any and all  injury,  loss,  damage,
obligation,  penalty or liability  (or any claims in respect of the  foregoing),
costs or expenses (including reasonable attorneys' fees and court costs) imposed
upon,  incurred by or asserted against SBA and arising from or on account of any
occurrence,  injury to or death of  persons  (including  workmen)  or loss of or
damage to property caused by the negligence or willful  misconduct of Horizon or
its agents, employees or contractors,  licensees, guests or invitees in the use,
operation, maintenance or repair of or on the Property, excepting matters caused
by the  negligence or willful  misconduct  of SBA and SBA's  agents,  employees,
representatives   and  contractors  (and  Horizon  shall  not  be  deemed  SBA's
contractor  for  purposes  hereof) or (ii) any  failure by Horizon to perform or
comply with any of the applicable  terms,  covenants or conditions of the MSA or
any applicable SLA.



                                       20
<PAGE>

          (b) Subject to Paragraph 18(b) above, SBA shall indemnify,  defend and
hold  Horizon  harmless  from and  against  any and all  injury,  loss,  damage,
obligation,  penalty or liability  (or any claims in respect of the  foregoing),
costs or expenses (including reasonable attorneys' fees and court costs) imposed
upon, incurred by or asserted against Horizon and arising from or on account of:
(i) any occurrence, injury to or death of persons (including workmen) or loss of
or damage to property  caused by the negligence or willful  misconduct of SBA or
SBA's agents, employees, contractors, licensees, subtenants, guests, invitees or
other persons on or about the Property other than Horizon and Horizon's  agents,
employees,  representatives  and  contractors  (and  SBA  shall  not  be  deemed
Horizon's  contractor for purposes hereof) or (ii) any failure by SBA to perform
or comply with any of the terms,  covenants or  conditions  of the Ground Lease,
this MSA or any applicable SLA.

          (c) SBA shall have no obligation to indemnify  Horizon from or against
nor shall Horizon be entitled to assert a claim against SBA for  incidental  and
consequential  damages  arising  from the  negligence  of SBA,  but SBA shall be
responsible   for  incidental  and   consequential   damages  arising  from  the
intentional  torts and  willful  misconduct  of SBA or SBA's  officers,  agents,
employees,  representatives,  invitees and contractors.  Likewise, Horizon shall
have no obligation to indemnify SBA from or against nor shall SBA be entitled to
assert a claim against Horizon for incidental and consequential  damages arising
from the negligence of Horizon,  but Horizon shall be responsible for incidental
and  consequential  damages  arising  from  the  intentional  acts  and  willful
misconduct of Horizon or Horizon's officers, agents, employees, representatives,
invitees or contractors.  The foregoing  waivers of incidental and consequential
damages  shall not apply to damages  attributable  to claims of third parties to
this Agreement.

     20. Cell Site on Wheels. Should Horizon experience a loss in communications
service  to its  customers  for any  reason,  Horizon  shall be,  and hereby is,
authorized,  to the fullest  extent  permissible by applicable law and ordinance
and  the  Ground   Lease,   to  bring  onto  the  Property  a  mobile   wireless
communications  facility  or COW  during  such  period of loss of service to the
extent space is available and further provided that the presence of the COW does
not materially interfere with the maintenance, repair and restoration efforts of
SBA or the other  tenants.  In the event that  Horizon  takes such action as the
result  of a breach or other  negligent  or  wrongful  act or  omission  of SBA,
Horizon shall be entitled to recover  against SBA (or, at Horizon's  option,  to
set off against  Rent  payable  hereunder)  the  reasonable  costs and  expenses
incurred by Horizon in implementing  and  maintaining  such facility during such
period and of removing the same upon the re-establishment of regular service.

     21.  Notices.  All  notices,  requests,  demands  and other  communications
hereunder shall be in writing and personally delivered against receipt,  sent by
overnight  delivery  by a  nationally  recognized  overnight  carrier or mailed,
certified mail, return receipt requested, addressed as follows:



                                       21
<PAGE>

                    If to Horizon, to:
                    ------------------
                    Horizon Personal Communications, Inc.
                    68 East Main Street
                    P.O. Box 480
                    Chillicothe, Ohio 45601-0480
                    Attn: Vice President, Technology

                    With a copy to:
                    ---------------
                    Lewellen & Frazier PLC
                    415 North McKinley, Suite 1240
                    Little Rock, AR 72205
                    Attention: Todd A. Lewellen

                    If to SBA, to:
                    --------------
                    SBA Towers, Inc.
                    Onetown Center Road, 3rd Floor
                    Boca Raton, Florida 33486
                    Attention: Site Administration

     All notices,  demands and requests shall be effective upon actual delivery,
if personally  delivered against receipt or delivered by overnight carrier,  or,
if mailed, on the date of the United States Postal Service  postmark;  provided,
however,  that the time  period in which a response  or action,  if any,  to any
notice,  demand or request must be given or completed shall commence to run from
the date of receipt of the notice,  demand or request by the addressee  thereof.
Rejection or failure to claim delivery of any such properly given notice, demand
or request, or any refusal to accept any such notice,  demand or request, or the
inability  to deliver  because of changed  address of which no notice was given,
shall be deemed to be receipt of the  notice,  demand or request  sent as of the
date of the United  States  Postal  Service  postmark  or the date of  attempted
personal  delivery  or  overnight  carrier  delivery,  as the  case  may be.  By
providing at least five (5) days' written notice thereof in accordance with this
Paragraph  21,  either  party  shall have the right from time to time and at any
time during the term of this MSA to change its address and to specify as its new
address any address within the continental United States of America.

     22. Quiet Enjoyment,  Title and Authority. SBA covenants and warrants that:
(i) SBA has full right, power and authority to execute this MSA and the power to
grant all rights and interests  hereunder;  (ii) SBA's execution and performance
of this MSA will not violate any laws, ordinances,  covenants, or the provisions
of any mortgage,  lease or other agreement  binding on SBA, and (iii) subject to
matters of record as of an SLA Commencement  Date and condemnation  proceedings,
Horizon  shall have the quiet  enjoyment  of each Site under this MSA during the
SLA Term. SBA shall indemnify  Horizon from and against any loss, cost,  expense
or damage  including  attorneys'  fees associated with a breach of the foregoing
covenant of quiet enjoyment Subject to Paragraph 22 (iii),  Horizon shall not be
disturbed in its use and occupancy of such Site or in the exercise of its rights
under  this  MSA or the  applicable  SLA as long as  Horizon  is not in  default
hereunder  beyond any  applicable  grace or cure period.  Horizon  covenants and


                                       22
<PAGE>

warrants  that:  (i) Horizon has the full right,  power and authority to execute
this MSA and perform its obligations hereunder, and (ii) Horizon's execution and
performance of this MSA will not violate any laws, ordinances, covenants, or the
provisions of any mortgage, lease or other agreement binding on Horizon.

     23. Environmental Laws.

          (a)  Horizon,  its heirs,  grantees,  successors,  and  assigns  shall
indemnify,  defend, reimburse and hold harmless SBA from and against any and all
damages,  caused by  activities  conducted on a Site by Horizon,  and either (i)
arising  from the presence of any  substance,  chemical or waste  identified  as
hazardous,  toxic or dangerous in any applicable federal,  state or local law or
regulation  including  petroleum  or  hydrocarbon  based  fuels  such as diesel,
propane or natural  gas  (collectively,  "Hazardous  Materials")  introduced  by
Horizon  upon,  about or beneath a Site or  migrating  from such  Site,  or (ii)
arising  out of the  violation  by  Horizon  of any  environmental  requirements
applicable to a Site or  applicable  to the  activities of Horizon on such Site.
Horizon  covenants  that it shall not nor  shall  Horizon  allow its  employees,
agents or independent  contractors  to treat,  store or dispose of any Hazardous
Materials on the Property except in accordance with applicable laws.

          (b) Except as set forth above, SBA, its heirs,  grantees,  successors,
and assigns shall  indemnify,  defend,  reimburse and hold harmless Horizon from
and against  any and all  damages  arising  from (i) the  presence of  Hazardous
Materials  upon,  about or beneath  any  Property  or  migrating  to or from the
Property  introduced  by SBA or its other  tenants,  or (ii)  arising out of the
violation  by  SBA or  its  other  tenants  of  any  environmental  requirements
pertaining to the Property and any activities thereon.

     24. Assignment and Subleasing.  Either party may assign all or a portion of
its rights,  title or interests  hereunder or under a particular SLA;  provided,
however,  that the proposed  assignee  shall agree in writing to be bound by the
terms and conditions of this MSA and each  applicable SLA. In the event that the
proposed  assignee  provides  audited (i) balance sheets and (ii)  statements of
operations prepared in accordance with GAAP which indicate that the assignee has
a financial  position,  as measured by reference to such  assignee's  net worth,
operating  results,  and working  capital,  which is  comparable  to that of the
assigning  party as of the date hereof,  the  assigning  party shall be released
from any and all obligations under the assigned instruments and for the assigned
Sites.  No  such  assignment  by  either  party  shall  affect  the  rights  and
obligations  of the other party  under this MSA. In the event that the  proposed
assignee  does  not  have a  financial  position  (as  defined  above)  which is
comparable to that of the assigning  party as of the date hereof,  the assigning
party shall remain liable for all obligations under the assigned instruments and
for the assigned Sites.  Notwithstanding  the foregoing,  Horizon shall have the
right without  having the  obligation to obtain the consent of SBA to assign any
SLA to West Virginia Alliance, LLC d/b/a Intellos. Horizon shall not be entitled
to assign its interest  under this MSA or an SLA to an entity  which  utilizes a
spectrum  different  than that of Horizon  unless it first  obtains  SBA's prior
written consent which consent shall not be conditioned or unreasonably  withheld
or delayed by SBA. SBA acknowledges that its consent to a proposed assignment by


                                       23
<PAGE>

Horizon to an entity which operates at a spectrum  different from Horizon's will
be  unreasonably  withheld  if the  operation  at said  spectrum  will not cause
interference  with the operation of other equipment at each applicable  Property
affected by the SLA  proposed to be assigned by Horizon.  Horizon  shall have no
right to sublease or  partially  assign its rights under any SLA unless it first
obtains SBA's prior written consent; however, SBA shall be entitled,  subject to
the other provisions hereof, to sublease or partially assign its rights under an
SLA without obtaining Horizon's prior consent.

     25. Notice of Proposed Third Party Use; Right of First Refusal.

          (a) In the event  that (i) SBA  makes or  receives  a bona fide  offer
pursuant to which a third party would enter into a lease,  sublease,  license or
other occupancy  agreement with respect to any portion of a Property (the "Right
of First  Refusal  Space")  during the term of this MSA and (ii) SBA  intends to
accept such offer,  then SBA shall  promptly send written  notice (the "Right of
First  Refusal  Notice") to Horizon  offering to lease or sublease  the Right of
First  Refusal  Space to Horizon  for the same rent and under the same terms and
conditions as the aforementioned bona fide offer (the "Right of First Refusal").
The Right of First Refusal Notice shall contain the following information:

                    (i) the price,  terms,  and  conditions for the occupancy of
          the Right of First  Refusal  Space,  the name of the  person or entity
          making  the offer  and a  description  of the  Right of First  Refusal
          Space;

                    (ii)  evidence  of the bona  fide  offer  such as a  written
          proposal,  term sheet or  proposed  contract  or a summary of a verbal
          offer; and

                    (iii)  provided  that  such  third  party is a  provider  or
          carrier  of  wireless   communications   services,  the  frequency  or
          frequencies,  proposed antenna  radiation center location and radiated
          power level and type of technology  (whether CDMA,  TDMA,  etc.) to be
          utilized by such third party on the Property.

          (b) Horizon shall have three (3) days after  Horizon's  receipt of the
Right of First  Refusal  Notice  in  accordance  with the  notice  provision  in
Paragraph  21 hereof  (which  three (3) day period is  referred to herein as the
"Acceptance Period") to elect to exercise the Right of First Refusal. If Horizon
elects to  exercise  the Right of First  Refusal,  Horizon  shall  notify SBA in
writing within the Acceptance  Period of Horizon's intent to exercise such right
whereupon  the Right of First  Refusal  shall become a binding  contract for the
lease or sublease of the Right of First Refusal Space and Horizon shall lease or
sublease the Right of First Refusal Space in  accordance  with such rent,  terms
and conditions.  If Horizon does not notify SBA in writing within the Acceptance
Period of  Horizon's  election  to exercise  its Right of First  Refusal on such
terms and conditions,  Horizon's right to exercise its Right of First Refusal on
such terms and conditions  shall  terminate.  This Paragraph 25 (b) shall not be
deemed to limit or alter Horizon's  relocation  rights set forth in Paragraph 14
of this MSA or to relieve Horizon of its obligations  under the SLA prior to the
exercise of the Right of First Refusal by Horizon.



                                       24
<PAGE>

     26. Right of First Refusal to Purchase.

          (a)  Except  in the  instance  of a sale of  substantially  all of the
assets of SBA or in the event of a merger or  reorganization  by SBA, if, at any
time  during the Term,  SBA  receives  a bona fide  offer from a third  party to
purchase any Property (the "Offer"),  which Offer SBA is prepared to accept, SBA
shall  promptly  transmit  to Horizon  its  written  offer (the  "First  Refusal
Notice")  to sell the  Property  to  Horizon  on the same  terms and  conditions
specified in the Offer.  Horizon  shall have ten (10) business days within which
to accept such offer.  If Horizon shall accept such offer by written notice (the
"Acceptance  Notice")  to SBA within said ten (10) day period  (such  Acceptance
Notice  shall  specify a closing  date which is the  earlier of thirty (30) days
from the date  thereof or the closing date  specified in the Offer),  such offer
and acceptance  shall constitute a contract between them for the sale by SBA and
the  purchase  by  Horizon  of the Site and shall not  thereafter  be subject to
rejection by either party.

          (b) If the  Offer  is not so  accepted  by  Horizon,  SBA may sell the
Property to such bona fide third party  purchaser on the terms  contained in the
Offer. Any such sale and transfer must be consummated  within 180 days following
the expiration of the time herein above provided for the acceptance of the Offer
by  Horizon.  If the  Property  is sold to such third  party,  the sale shall be
subject to this MSA and the  applicable  SLA and all of the  provisions  hereof,
including the right of first refusal provided in this Paragraph 26.

     27. Waiver of SBA's Lien.  SBA hereby waives any and all lien rights it may
have,  statutory  or  otherwise,  with  respect to the  Equipment or any portion
thereof.  The Equipment shall be deemed  personal  property for purposes of this
MSA and any SLA,  regardless  of whether any  portion  thereof is deemed real or
personal property under applicable law.

     28.  Conditions  Precedent.  SBA  shall  have the right to  terminate  this
Agreement  if the  following  conditions  have not been  satisfied  prior to the
Closing  (as that  term is  defined  in the  APA):  1) a BTS  Agreement  in form
substantially  similar to this  Agreement  has been entered into between  Bright
PCS,  LLC and SBA;  and 2) this  Agreement  has been  approved  by the  Board of
Directors  of SBA.  In the  event  that SBA  fails to  obtain  approval  of this
Agreement  by its Board of Directors  on or before  September 1, 1999,  this MSA
shall  terminate  and SBA shall pay to  Horizon  the sum of Fifty  Thousand  and
No/100 Dollars ($50,000.00).

     29. Confidential Information.

          (a) Use of Confidential Information. In order to permit the parties to
perform their respective obligations under this Agreement,  each party may, from
time to time,  disclose to the other  confidential  or proprietary  information.
Such  confidential  or proprietary  information  and the terms of this Agreement
shall  constitute   "Confidential   Information".   Each  party  shall  use  all
Confidential  Information  solely for the purpose of performing its  obligations
under this  Agreement.  Neither party shall disclose to any other person,  other
than employees or agents of the party who agree,  in writing,  to be bound by an
equivalent undertaking, any Confidential Information. SBA agrees not to disclose
any of Horizon's  Confidential  Information to a competitor of Horizon.  Horizon
agrees not to disclose any of SBA's Confidential  Information to a competitor of
SBA.



                                       25
<PAGE>

          (b) Exceptions.  The  aforementioned  restrictions  shall apply to all
Confidential Information with the exception of the following:

                    (i) Confidential  Information which is made public by either
          party while  performing  under this Agreement or which otherwise is or
          hereafter  becomes part of the public domain  through no wrongful act,
          fault, or negligence on the part of the other party;

                    (ii)  Confidential  Information which a party can reasonably
          demonstrate  is already in such party's  possession and not subject to
          an existing agreement of confidentiality;

                    (iii)  Confidential  Information  which is  received  from a
          third party  without  restriction  and without  breach of an agreement
          with Horizon or SBA;

                    (iv)   Confidential   Information   which  is  independently
          developed by a party as evidenced by its records; or

                    (v) Confidential  Information which either party is required
          to disclose pursuant to a valid order of a court or other governmental
          body or any  political  subdivision  thereof;  provided  that,  to the
          extent that it may lawfully do so, the disclosing  party shall provide
          the affected party with immediate  written notice of the nature of the
          required  disclosure and shall, where appropriate,  provide that party
          with the  opportunity to interpose an objection or obtain a protective
          order   restricting  the  use  and  disclosure  of  the   Confidential
          Information; or

                    (vi) in defense of a legal action or otherwise required by a
          governmental agency or applicable law.

     30. Miscellaneous.

          (a) Each  party  agrees  to  furnish  to the  other and to a person or
entity designated by the requesting party, within twenty (20) days after receipt
of written  request  such  truthful  estoppel  information  as either  party may
reasonably request.

          (b) Each party agrees to execute any documents (including a short form
or memorandum of lease, easement agreement or both) requested by the other party
to confirm of record its  rights  under this MSA or any SLA (but  excluding  the
economic  terms  hereof).  Unless the laws of the state in which the Property is
located prohibit the recordation of a short form or memorandum of lease, neither
party shall record this MSA, but may record, in lieu thereof, the aforementioned
short  form or  memorandum  of lease or the SLA.  In the event of a  recordation
prohibition  described above,  either party may record any SLA. Either party may
record any easement agreement.



                                       26
<PAGE>

          (c)  This  MSA,  the BTS  Agreement  and the  Antenna  Site  Agreement
including  all  SLAs,  exhibits  attached  hereto  and  incorporated  herein  by
reference,  constitutes the sole and entire agreement between the parties hereto
with respect to the subject  matter hereof and  supersedes  all  understandings,
contracts,  promises,  covenants,  representations,  statements,  agreements and
undertakings  (whether written or oral), with respect thereto made prior to, the
execution  and delivery of this MSA with the exception of the Agreement for Use,
Non-Disclosure  of  Proprietary  Information.  This  MSA or any  SLA  may not be
modified  or  amended,  except by a written  instrument  signed by both  parties
hereto. This MSA, SBA's rights and Horizon's rights hereunder shall be deemed to
be and hereby are  incorporated  by reference  into each SLA for a Site and this
MSA and each SLA shall run with and burden title to each Site and Property  and,
except as otherwise  provided  herein,  the  provisions of this MSA and each SLA
shall be binding  upon and shall inure to the benefit of the parties  hereto and
their  respective  heirs,  administrators,   executors,  legal  representatives,
successors and permitted  assigns.  The paragraph  captions and headings used in
this  MSA are for  convenience  of  reference  only and  shall  not  affect  the
construction  to be given any of the  provisions  hereof.  If the time period or
date by which or on which any right,  option or election provided under this MSA
must be exercised,  or by which or on which any act required  hereunder  must be
performed, or by which or on which any notice must be given or received, expires
or occurs on a  Saturday,  Sunday or a holiday  observed by state  chartered  or
national banks in the state or commonwealth in which the Site are located,  then
such time period or date shall be automatically  extended through the end of the
next  day  which is not a  Saturday,  Sunday  or such a  holiday.  All  exhibits
attached to this MSA and referred to herein are deemed  incorporated in this MSA
by reference.

          (d) Whenever possible, each provision of this MSA shall be interpreted
in such manner as to be  effective  and valid under  applicable  law, but if any
provision of this MSA shall be prohibited by or invalid  under  applicable  law,
such provision  shall be ineffective  only to the extent of such  prohibition or
invalidity,  without  invalidating  the  remainder  of  such  provision  or  the
remaining provisions of this MSA.

          (e) This  MSA does  not,  and  shall  not be  construed  to,  create a
partnership or joint venture or any other  relationship  between SBA and Horizon
other than the  relationship of lessor and lessee under the laws of the state or
commonwealth in which each Property is located.

          (f) This MSA shall be governed by, and construed in  accordance  with,
the laws of the state where the applicable Site is situated.

          (g) This MSA may be executed in two or more counterparts, all of which
shall be considered one and the same  agreement and shall become  effective when
one or more counterparts  have been signed by the each of the parties,  it being
understood that all parties need not sign the same counterpart.

          (h) Horizon  shall be entitled to pursue NDAs with the Ground  Lessors
for each Site;  provided,  however,  that SBA shall have the right to review and
approve,  which  approval  shall not be  unreasonably  conditioned,  delayed  or
withheld, all correspondence which is sent to the Ground Lessors.  Horizon shall
provide SBA with copies of all such correspondence for SBA's files.



                                       27
<PAGE>

          (i) No Brokers;  Indemnification  from Broker's Fees.  Horizon and SBA
hereby  represent,  agree and  acknowledge  that no  broker  or other  person is
entitled to claim or to be paid a commission  as a result of the  execution  and
delivery of this MSA. Each of the parties shall  indemnify,  defend and hold the
other  party  harmless  for  all  claims,  damages,   liabilities  and  expenses
(including  attorney's fees) arising from a  misrepresentation  arising from the
first sentence of this paragraph.

     IN WITNESS  WHEREOF,  SBA and Horizon have duly executed and delivered this
MSA. The party last  executing  this MSA shall insert the date of such execution
on the first page hereof, which date shall be the Date of this MSA.

                                     PURCHASER:
                                     SBA TOWERS, INC.


                                     By:______________________________

                                     Title:___________________________

                                     Attest: _________________________

                                     Title:___________________________

                                             [CORPORATE SEAL]


                                     HORIZON PERSONAL
                                     COMMUNICATIONS, INC.:


                                     By:______________________________

                                     Title:___________________________



                                       28
<PAGE>


                                 ATTACHMENT "A"
                                       SLA

                            SITE LEASE ACKNOWLEDGMENT

     This Site Lease Acknowledgment  ("SLA") is made and entered into as of this
________ day of ______________,  1999, by and between  ______________________  ,
hereinafter designated as "Horizon" and  __________________________  hereinafter
designated as "SBA",  pursuant and subject to that certain Master Site Agreement
("MSA") by and between the Parties hereto, dated as of March ________, 1999. All
capitalized terms have the meanings ascribed to them in the MSA.

     1. The Site  leased by SBA to  Horizon  shall  consist  of the Cable  Path,
Easements, Tower Space, and Ground Space, as those terms are defined in the MSA.
The Site is a portion of that certain portion of that real property,  located in
the  City of  ____________,  the  County  of  _____________,  and the  State  of
____________,  more  particularly  described in the Memorandum of Lease which is
recorded in Book ___, Page ___ [or as Instrument  Number  _____________]  in the
office of the  ___________________ of ______________  County,  ____________ (the
Property").  The Property is described in Exhibit "1" attached hereto and made a
part hereof.

     2. Horizon has installed at the Site the Grandfathered  Equipment set forth
in Exhibit "2" which shall be completed, attached and incorporated herein within
180 days of the SLA  Commencement  Date in accordance with paragraph 2(c) of the
Agreement  This  paragraph  shall only apply to  Conveyed  Sites as that term is
defined in the MSA.

     3.  The  commencement  date  of  the  SLA  ("SLA  Commencement   Date")  is
_____________,  1999.  The first (1st) monthly rental payment is due and payable
by Horizon to SBA on the SLA Commencement Date in accordance with Paragraph 4 of
the  Agreement.  Any future rent  adjustments  shall be calculated in accordance
with Paragraph 4 of the Agreement.

     4. The term of this SLA is ten (10) years beginning on the SLA Commencement
Date.  The term of the SLA will  automatically  renew for three (3)  additional,
consecutive  five (5) year  terms  unless  Horizon  notifies  SBA in  writing of
Horizon's intention not to renew as provided in Paragraph 3(c) of the MSA.

     5. Horizon has been granted certain preferential rights pursuant to the MSA
which may  affect  subsequent  tenants  or  purchasers  of the  Property.  These
preferential  rights  include a right of first refusal to purchase the Property,
the right of first refusal to lease  additional space on the tower, the right to
relocate its equipment to a different  height on the tower, the right to install
additional  equipment on the Property  (subject to such  limitations to install,
modify or replace the  equipment  as may be  provided in the MSA),  the right to
place a mobile  telecommunications  facility  on the  property  in the event the
existing  tower  facilities  are damaged or destroyed,  and the right to be free
from interference from subsequent tenants.

                                       29
<PAGE>


     IN WITNESS  WHEREOF,  the  parties  hereto have set their hands and affixed
their respective seals the day and year first above written.


ATTEST:                           _____________________________________
                                  d/b/a  HORIZON

____________________              By:__________________________________

                                  Title:_______________________________


ATTEST:                           _____________________________________
                                  d/b/a SBA COMMUNICATIONS

____________________              By:_________________________________

                                  Title:______________________________


                               [ACKNOWLEDGEMENTS]


                                       30
<PAGE>


                             Exhibit "1" TO THE SLA
                             ----------------------

                        LEGAL DESCRIPTION OF THE PROPERTY


[FOR  CONVEYED  SITES,  THIS  DESCRIPTION  SHOULD BE TAKEN FROM THE MOL FILED BY
HORIZON AND SHOULD INCLUDE ALL INGRESS/EGRESS AND UTILITY EASEMENTS]



                                       31
<PAGE>


                             Exhibit "2" to the SLA
                             ----------------------

                             GRANDFATHERED EQUIPMENT


For Conveyed Sites,  this Exhibit shall be completed,  attached and incorporated
herein within 180 days of SLA  Commencement  Date in accordance  with  paragraph
2(c) of the Agreement

Antenna manufacturer and type-number:                   ------------------

Number of antennas:                                     ------------------

Weight and dimension of antenna(s) (LxWxD):             ------------------

Transmission line mfr. & type no.:                      ------------------

Diameter & length of transmission line:                 ------------------

Location of antennas for Grandfathered Equipment
(as described in Exhibit 3" attached hereto and
made a part hereof):                                    ------------------

Height of antenna(s) on structure:                      ------------------

Direction of radiation:                                 ------------------

Ground Space for Grandfathered Equipment
(equipment building/floor space dimensions
as described in Exhibit "4" attached hereto
and made a part hereof):                                ------------------

Frequencies/Max Power Output:                           ------------------

Grounding specifications for Grandfathered
Equipment (as described in Exhibit "5"
attached hereto and made a part hereof):                ------------------

Generator services, if any:                             ------------------


                                       32
<PAGE>


                             Exhibit "3" to the SLA
                             ----------------------

                              LOCATION OF ANTENNAS


[FOR CONVEYED  SITES,  THIS EXHIBIT SHALL BE COMPLETED BY SBA WITHIN 180 DAYS OF
THE SLA COMMENCEMENT DATE AND SHALL BE SUBJECT TO HORIZON'S WRITTEN APPROVAL]


                                       33
<PAGE>

                             Exhibit "4" to the SLA
                             ----------------------

                  DESCRIPTION OF EQUIPMENT BUILDING/FLOOR SPACE


[FOR CONVEYED  SITES,  THIS EXHIBIT SHALL BE COMPLETED BY SBA WITHIN 180 DAYS OF
THE SLA COMMENCEMENT DATE AND SHALL BE SUBJECT TO HORIZON'S WRITTEN APPROVAL.]


                                       34
<PAGE>


                             Exhibit "5" to the SLA
                             ----------------------

                            GROUNDING SPECIFICATIONS


[FOR CONVEYED  SITES,  THIS EXHIBIT SHALL BE COMPLETED BY SBA WITHIN 180 DAYS OF
THE SLA COMMENCEMENT DATE AND SHALL BE SUBJECT TO HORIZON'S WRITTEN APPROVAL.]



                                       35
<PAGE>


                                 ATTACHMENT "B"
                                 --------------

                          ANTENNA SITE LEASE AGREEMENT

                        CONFIDENTIAL TREATMENT REQUESTED

     Confidential Portions of this Agreement Which Have Been Redacted Are Marked
With  ("[***]").  The  Omitted  Material  Has  Been  Filed  Separately  With The
Securities and Exchange Commission.

                      ATTACHMENT B TO MASTER SITE AGREEMENT

                             ANTENNA SITE AGREEMENT


1.   PREMISES AND USE. SBA Towers, Inc., a Florida corporation "Owner" leases to
     _______________,  a  Delaware  Corporation,  "Tenant,"  the site  described
     below:

     Check appropriate box(es)

     Tower antenna space;

     Pad or Shelter space for placement of base station equipment  consisting of
     approximately _________ square feet; of space; or

     Space required for cable runs to connect  telecommunications  equipment and
     antennas,   in  the  location(s)  shown  on  Exhibit  A,  together  with  a
     non-exclusive   easement  for   reasonable   access   thereto  and  to  the
     appropriate,  in the discretion of Tenant, source of electric and telephone
     facilities,  collectively,  the "Site." The Site will be used by Tenant for
     the purpose of installing,  removing, replacing, modifying, maintaining and
     operating,  at its expense,  a  telecommunications  service system facility
     consisting of the antenna(s)  and related  equipment set forth on Exhibit B
     the  "Equipment."  If Tenant  desires to place  equipment on the Site other
     than  that  listed on  Exhibit  B,  Owner and  Tenant  will  negotiate  the
     placement of the additional  equipment and the associated  increased  rent.
     Any personal property owned by Tenant whether fixed or attached to the Site
     or the Tower shall remain the exclusive  property of Tenant  without regard
     to whether the personal property is described on Exhibit B. Tenant will use
     the Site in a manner which will not  unreasonably  disturb the occupancy of
     Owner's other tenants.

2.   CONDITIONS  PRECEDENT.  Tenant's obligation to perform under this Agreement
     shall be subject to and conditioned upon:

     (a)  Tenant securing  appropriate  approvals after making diligent  efforts
          for Tenant's intended use of the Site from the Federal  Communications
          Commission, the Federal Aviation Administration and any other federal,
          state or local regulatory  authority having jurisdiction over Tenant's
          proposed use of the Site;

     (b)  Tenant shall have the right to obtain a title report or commitment for
          a title policy from a title  insurance  company of its choice.  If, in
          the  opinion of the  Tenant,  such title  report  shows any defects of
          title or liens or encumbrances  which adversely affect Tenant's use of
          the Site or Tenant's ability to obtain financing, Tenant shall have no
          obligation to perform under this Agreement;

                                       1
<PAGE>

     (c)  Tenant  shall  have the  right to have the Site  surveyed  and to have
          structural  tower  studies,  radio  frequency  engineering  and  other
          engineering  analyses  performed.  In the event that any  defects  are
          shown by the survey or the engineering analyses,  which in the opinion
          of Tenant, may adversely affect Tenant's use of the Site. Tenant shall
          have the right to  cancel  this  Agreement  immediately  upon  written
          notice to Owner; and

     (d)  Tenant shall have the right to have an environmental audit of the Site
          performed by an  environmental  consulting  firm of Tenant's choice at
          Tenant's  cost.  If the  environmental  audit reveals that the Site is
          contaminated  with  Hazardous  Materials,  as that term is hereinafter
          defined,  Tenant  shall  have no  obligation  to  perform  under  this
          Agreement; and

     (e)  Tenant may conduct radio frequency  propagation studies ("RF Studies")
          on the Site. If the RF Studies do not provide  results which meet with
          the personal  satisfaction of Tenant,  Tenant shall have no obligation
          to perform  under this  Agreement.  Tenant shall have 60 days from the
          Possession  Date ("Review  Period") to perform the  conditions in this
          section.  Tenant's inability to successfully  satisfy these conditions
          or the  occurrence  of any other  event  which  effectively  prohibits
          Tenant's  intended  use of the  Site  shall  relieve  Tenant  from any
          obligation to perform under this Agreement and shall entitle Tenant to
          restitution  of any unearned  rental  payments which have been paid to
          Owner during the Review  Period.

          Owner's obligation to perform under this Agreement shall be subject to
          and  conditioned  upon Tenant  providing  Owner with a copy of the FAA
          Determination   of  No  Hazard  which  grants   approval  to  Tenant's
          frequencies and power (ERP) to be used at the Site.  Tenant shall make
          diligent efforts to obtain such  Determination  and shall have 60 days
          from the Possession Date to perform this condition. Tenant's inability
          to  successfully  satisfy this condition  shall relieve Owner from any
          obligation to perform under this Agreement at Owner's option.


                                       2
<PAGE>
                                        [***] - CONFIDENTIAL TREATMENT REQUESTED


3.   TERM. The term "Initial  Term" of the Agreement is five years  beginning on
     the  earlier of (i)  fifteen  (15) days from the date that  Owner  provides
     notice  to  Tenant  that the Site is ready  for  Tenant's  installation  of
     Equipment,  or (ii) the date on which Tenant commences  installation of any
     of its  Equipment  at  the  Possession  Site  ("Possession  Date").  If the
     Possession Date is the first day of a calendar  month,  the Possession Date
     shall  also  be  the  Commencement  Date  ("Commencement   Date").  If  the
     Possession  Date  falls on a day other  than the  first  day of a  calendar
     month,  the first day of the calendar month  following the Possession  Date
     shall   constitute   the   Commencement   Date.   This  Agreement  will  be
     automatically  renewed  for three (3)  additional  terms  (each a  "Renewal
     Term") of five years each, unless Tenant provides Owner notice of intention
     not to renew not less than  one-hundred  and twenty (120) days prior to the
     expiration of the Initial Term or any Renewal  Term.

4.   RENT.  Beginning on the first  anniversary of the  Commencement  Date, Rent
     will be paid in advance in equal  monthly  payments  of [***] for the first
     twelve months following the first  anniversary of the Commencement Date and
     will be increased  annually on the anniversary of the Commencement  Date by
     [***] of the  yearly  rate in effect  for the  prior  year.  Rent  shall be
     apportioned  for any  fractional  year in  which  the  Initial  Term or the
     Renewal Term begins or ends.  Payments ONLY shall be sent to Dept. #215595,
     Miami, Florida 33121-5595.

5.   TITLE AND QUIET  POSSESSION.  Owner  represents  and  agrees (a) that is in
     possession  of the Site as ? fee  owner or ? lessee  under a ground  lease,
     ("Ground  Lease;") (b) that it has the right to enter into this  Agreement;
     (c) that the person  signing this  Agreement has the authority to sign; and
     (d) that Tenant is entitled to the quiet  possession of the Site subject to
     zoning and other  requirements  imposed by  governmental  authorities,  any
     easements,  restrictions,  or encumbrances of record throughout the Initial
     Term and each Renewal  Term so long as Tenant is not in default  beyond the
     expiration  of any cure  period.  Notwithstanding  anything to the contrary
     contained in this  Agreement,  if the Site is subject to the Ground  Lease,
     Owner may terminate this Agreement upon the termination of Owner's right to
     possession of the Site under the Ground Lease.  Owner will not do, attempt,


                                       3
<PAGE>

     permit or suffer  anything  to be done  which  could be  construed  to be a
     violation of the Ground Lease nor shall Owner surrender the Ground Lease to
     the Ground Lessor, enter into any amendment of the Ground Lease which would
     adversely affect Tenant,  fail to observe or perform any obligation imposed
     upon  Owner as the  tenant  under the Ground  Lease  beyond any  applicable
     notice or grace  period.  Provided  Tenant  exercises its election to renew
     this Agreement in accordance with the terms of this Agreement,  Owner shall
     renew the Ground Lease to assure Tenant the quiet and peaceful enjoyment of
     the Site for the Initial Term and any Renewal Term of this Agreement.  Upon
     request  from Tenant,  Owner will furnish  Tenant with a copy of the Ground
     Lease (with  business  terms  deleted)  attached  hereto as Exhibit E. This
     Agreement  is  subordinate  to any  mortgage or deed of trust now of record
     against the Site.  Promptly  after this  Agreement  is fully  executed,  if
     requested by Tenant,  Owner will request the holder of any such mortgage or
     deed of trust to execute a non-disturbance  agreement in a form provided by
     Tenant,  and Owner will  cooperate  with  Tenant at Tenant's  sole  expense
     toward such an end to the extent that such cooperation does not cause Owner
     additional financial  liability.  Owner will request that the Ground Lessor
     execute a non-disturbance  agreement in a form provided by Tenant and Owner
     will  cooperate  with Tenant at Tenant's sole expense toward such an end to
     the extent that such cooperation does not cause Owner additional  financial
     liability.  Tenant will not, directly or indirectly, on behalf of itself or
     any third party, communicate, negotiate, and/or contract with the lessor of
     the Ground Lease without first  providing  advance  written notice to Owner
     specifying  the purpose  for said  communications  with Owner.  In no event
     shall Tenant seek to interfere with the  contractual  relationship  between
     Owner and the lessor of the Ground Agreement.  A default by Owner under the
     Ground  Lease,  beyond  the  applicable  notice  or  grace  period,   shall
     constitute  a default  under this  Agreement.  Owner shall  provide  Tenant
     notice of any  default by Owner  under the Ground  Lease not less than five
     (5) days after the event of default. Tenant shall have the right to set-off
     against  the rent  accruing  hereunder  any sums  paid by  Tenant to cure a
     default by Owner under the Ground Lease.

6.   ASSIGNMENT/SUBLETTING. Tenant will not assign or transfer this Agreement or
     sublet all or any portion of the Site in  contravention  of this  Agreement
     without  the prior  written  consent of Owner,  which  consent  will not be
     unreasonably withheld,  delayed or conditioned.  However, tenant may assign


                                       4
<PAGE>

     without  the  Owner's  prior  written  consent  to any  party  controlling,
     controlled  by or  under  common  control  with  Tenant  provided  that the
     assuming  party  has  comparable  credit  quality  to  that of  Tenant.  An
     assignment,  transfer  or  sublet by Tenant  as  described  above  will not
     relieve Tenant of any obligations or liability hereunder.  Tenant may, upon
     notice to Owner,  mortgage or grant a security  interest in this  Agreement
     and the  Equipment  and may assign this  Agreement and the Equipment to any
     such  Secured  Parties or holders of  security  interests  including  their
     successors and assigns  (hereinafter  collectively  referred to as "Secured
     Parties").  In such event,  Owner shall  execute  such consent to leasehold
     financing as may reasonably be required by Secured Parties. Owner agrees to
     notify Tenant and Tenant's Secured Parties simultaneously of any default by
     Tenant and to give  Secured  Parties  the same right to cure any default as
     Tenant  except that the cure period for any Secured Party shall not be less
     than 10 business days after the receipt of the default  notice.  Tenant may
     assign  this  Agreement  without the  consent of Owner to an  affiliate  of
     Tenant or to an entity which acquires Tenant's  communications license from
     the Federal Communications Commission. In the event an assignment occurs as
     stated herein,  the assuming party must have  comparable  credit quality to
     that  of  Tenant.  If a  termination,  disaffirmance  or  rejection  of the
     Agreement  pursuant to any laws  (including  any  bankruptcy  or insolvency
     laws) by Tenant shall occur, or if Owner shall terminate this Agreement for
     any reason, Owner shall terminate this Agreement for any reason, Owner will
     give to the Secured  Parties  prompt notice thereof and Owner will give the
     Secured  Parties  the right to enter upon the Site  during a 30-day  period
     commencing  upon the Secured Party's receipt of such notice for the purpose
     of removing any  Equipment.  Owner  acknowledges  that the Secured  Parties
     shall  be  third-party  beneficiaries  of this  Agreement.

7.   ACCESS AND SECURITY. Tenant will have the reasonable right of access to the
     Site where its equipment is located;  provided that, Tenant must give Owner
     twenty-four  (24) hour  notice  for  access to climb the  tower;  all other
     access to the ground  equipment  shall be available 24 hours/7 days a week.


                                       5
<PAGE>

     In the event of an emergency  situation which poses an immediate  threat of
     substantial  harm or damage  to  persons  and/or  property  (including  the
     continued  operations  of  Tenant's  telecommunications   equipment)  which
     requires entry on the Site,  Tenant may enter the Site and take the actions
     that are  required to protect  individuals  or personal  property  from the
     immediate  threat of  substantial  harm or damage;  provided  that promptly
     after the  emergency  entry and in no event  later  than  twenty-four  (24)
     hours,  Tenant  gives  telephonic  and written  notice to Owner of Tenant's
     entry onto the Site.

     ACCESS  NOTICE  SHALL BE SUBMITTED  TO SBA TOWERS,  INC.,  DIRECTOR OF SITE
     MANAGEMENT.

8.   NOTICES. All notices must be in writing and are effective when deposited in
     the U.S. mail,  certified and postage  prepaid,  or when sent via overnight
     delivery, to the address set forth below, or as otherwise provided by law.

     Owner:  SBA Towers, Inc.
     One Town Center Road, 3rd Floor
     Boca Raton, FL 33486
     Attention:  Site Administration
     (800) 487-7483
     Tax I.D.:  65-0754577

     Tenant:



     Tax I.D.:

9.   INSTALLATION  AND  IMPROVEMENTS.   Prior  to  installing  or  allowing  any
     Equipment to be installed at the Site or making any changes,  modifications
     or alterations to such Equipment,  Tenant, at its expense,  will obtain all
     required  governmental  approvals  and  will  submit  to  Owner  plans  and
     specifications  and  proposed  dates of the planned  installation  or other
     activity,  proposed to be performed,  for Owner's  approval  which approval
     will not be  unreasonably  withheld,  including,  if requested by Owner,  a
     tower loading study and/or an intermodulation study performed and certified
     by an independent licensed  professional  engineer.  All installation of or


                                       6
<PAGE>
                                        [***] - CONFIDENTIAL TREATMENT REQUESTED

     other work on Tenant's  equipment will be at Tenant's sole expense and will
     be performed by Owner or one of Owner's  affiliates or  subsidiaries  which
     services  shall be performed at fair market rates.  In the event that Owner
     does not offer to perform such services at fair market  rates,  Tenant will
     have the right to utilize a  different  subcontractor  to perform the work,
     provided,  however,  that Tenant shall give Owner the right to perform such
     work at the price at which the subcontractor that Tenant wished to hire has
     offered to perform such work. Any  subcontractor  must be approved by Owner
     prior to commencement of work. All installations, operation and maintenance
     of  Equipment  must be in  accordance  with  Owner's  policies set forth in
     EXHIBIT D. All installation of or other work on Tenant's  equipment will be
     at Tenant's  sole  expense.  If the work is performed by someone other than
     Owner  or  Owner's  affiliate,  upon  completion  of  installation  of  any
     Equipment on the Site,  Owner will have the right to inspect and reasonably
     approve  all  installation  work.  Owner  reserves  the  right to  prohibit
     operation of any Equipment it reasonably deems to be improperly  installed,
     unsafe or not included in the  installation  design  plan.  Owner agrees to
     cooperate with Tenant's  reasonable  requests,  at Tenant's  expense,  with
     respect to obtaining  any required  zoning  approvals  for the Site and any
     improvements.  Upon  termination  or expiration of this  Agreement,  Tenant
     shall  remove its  Equipment  and  Improvements  and will repair any damage
     caused  by the  removal  of the  Equipment  from the Site to the  condition
     existing on the  Commencement  Date,  except for the ordinary wear and tear
     and insured  casualty  loss. So long as Tenant's  Equipment  remains on the
     Site after the termination date (even if it has been disconnected),  Tenant
     will  pay to Owner a  hold-over  fee  equal to [***] of the  then-effective
     monthly  rent  ("Hold-Over  Fee"),  prorated  from  the  effective  date of
     termination  to the date the  Equipment is removed from the Site,  provided
     the  equipment  is  removed  within  120  days  of the  effective  date  of
     termination or expiration ("Removal Period").  If Tenant's equipment is not
     removed within 45 days after the Removal Period, Owner shall have the right
     to disconnect and remove Tenant's equipment and Tenant will continue to pay
     the Hold-Over Fee.

10.  COMPLIANCE  WITH LAWS.  Tenant  agrees to take the Site in strictly "AS IS"
     condition subject, however to the Owner's obligation to maintain and repair
     and further  subject to the  representations,  warranties  and  indemnities
     given in this  Agreement  by Owner.  Owner  represents  that the Site,  its
     property contiguous thereto,  and all improvements  located thereon, are in


                                       7
<PAGE>

     substantial  compliance  with building,  life/safety,  disability and other
     laws, codes and regulations of applicable governmental authorities.  Tenant
     will  substantially  comply  with  all  applicable  laws  relating  to  its
     possession  and use of the Site and its  Equipment.  Upon request by Owner,
     Tenant will produce  satisfactory  evidence that all equipment installed at
     the Site complies with federal  regulations  pertaining to  radio-frequency
     radiation  standards  and is licensed  with the FCC, if  applicable.  Owner
     accepts sole  responsibility  for the Site's  compliance  with all tower or
     building  marking  and  lighting  regulations  promulgated  by the  Federal
     Aviation  Administration  "FAA" or the  Federal  Communications  Commission
     "FCC," as applicable.  Owner represents and warrants that the Site complies
     with all  applicable  tower or  building  making  or  lighting  regulations
     promulgated by the FAA or the FCC. Owner agrees that Tenant may install, at
     Tenant's  sole cost and expense and as required for Tenant's  Equipment,  a
     (i) within the Site,  backup generator to provide backup power in the event
     of a power outage at the Site,  and/or (ii) tower lighting alarm monitoring
     system  (including,  but not limited to,  commercial  power and a dedicated
     surveillance  telephone  line) to monitor the status of the  tower/building
     lighting.   Tenant's   installation   of  such  backup   generator   and/or
     tower/building  lighting alarm monitoring  system will not relieve Owner of
     its primary  responsibility  for compliance  with all  applicable  tower or
     building marking and lighting requirements.

11.  INSURANCE.  Tenant  and  Owner  will each  procure  and  maintain  a public
     liability policy,  with limits of $1,000,000 for bodily injury,  $1,000,000
     for property damage, $2,000,000 aggregate,  which minimum Owner may require
     adjusting  at each  Renewal  Term,  with a  certificate  of insurance to be
     furnished to the other  within  thirty (30) days of written  request.  Such
     policy  will  provide  that  cancellation  will not occur  without at least
     fifteen (15) business days prior written  notice to the other party to this
     Agreement.  Tenant will cause Owner to be named as an additional insured on
     such  policy  and Owner  will  cause  Tenant  to be named as an  additional
     insured on such policy.  Owner shall also maintain at Owner's sole cost and


                                       8
<PAGE>

     expense a fire and extended coverage casualty insurance policy insuring the
     Tower  and  related  improvements  for  its  full  replacement  value.  All
     insurance  policies required under this Agreement shall contain a waiver of
     subrogation provision under the terms of which the insurance carrier waives
     all of its rights to proceed  against Owner or Tenant,  as the case may be.
     If waivers of subrogation are obtained,  the party procuring such insurance
     shall use its best efforts to obtain a certificate of insurance which notes
     the  waiver of  subrogation  and a copy of the  insurance  which  notes the
     waiver of subrogation and a copy of the insurance policy  endorsement which
     evidenced  the  insurance  carrier's  assent to the waiver of  subrogation.
     Owner  and   Tenant   each   release   the   other  and  their   respective
     representatives  from any  claims by them or any one  claiming  through  or
     under them by way of  subrogation  or otherwise for damage to any person or
     to the  Site  and to the  fixtures,  personal  property,  improvements  and
     alterations  in or on the Site  that are  caused by or  result  from  risks
     insured against under any insurance  policy carried by them and required by
     this Agreement; provided that such releasees shall be effective only if and
     to the  extent  that the  same do not  diminish  or  adversely  affect  the
     coverage  under  such  insurance  policies.  Owner  shall  be  named  as an
     additional  insured on any insurance  policy  procured by Tenant and Tenant
     shall be named as an additional insured on any insurance policy procured by
     Owner pursuant to this Agreement. Owner shall seek to obtain from any other
     subsequent occupant of the Site a waiver of subrogation provision under the
     terms of which the other  occupant's  insurance  carrier  waives all of its
     rights to proceed  against  Tenant.  If Tenant is notified that a waiver of
     subrogation  has been  obtained  for the  benefit of Tenant  from the other
     occupant,  Tenant shall also seek to obtain a waiver of subrogation for the
     benefit  of the  occupant  who  obtained  a waiver of  subrogation  for the
     benefit of the Tenant.  If waivers of subrogation  are obtained,  the party
     procuring such insurance shall use its best efforts to obtain a certificate
     of  insurance  which  notes  the  waiver of  subrogation  and a copy of the
     insurance policy endorsement which evidenced the insurance carrier's assent
     to the waiver of subrogation.

12.  INTERFERENCE.  Tenant  understands  that  it is  the  intent  of  Owner  to
     accommodate  as many users as possible and that Owner may rent space to any
     other entity or person(s) desiring its facilities.  Tenant shall not cause,
     by its  transmitter  or other  activities,  interference  to Owner or other
     tenants  that have  previously  commenced  rental  payments.  Tenant  shall


                                       9
<PAGE>

     provide  Owner with a list of  frequencies  to be used at the site prior to
     putting said  frequencies  into  operation.  If  interference  occurs which
     involves  Tenant,  Owner  may  require  that an  intermodulation  study  be
     conducted at Tenant's cost. If Owner  determines  that the  interference is
     the  responsibility  of Tenant,  Owner will notify  Tenant and Tenant shall
     have  five (5)  business  days  from  the date of  notice  to  correct  the
     interference and if not corrected, Tenant shall cease, and Owner shall have
     all rights to any legal means  necessary  including  injunctive  relief and
     self  help  remedies  to cause  Tenant to cease,  transmission  except  for
     intermittent  testing for the purpose of correcting  the  interference.  If
     interference  cannot be  corrected  within  sixty (60)  calendar  days from
     Tenant's receipt of Owner's notice, then Owner may terminate this Agreement
     without  further  obligations  to Tenant.  Owner shall be  responsible  for
     curing any and all interference to the operation of the Equipment caused by
     the  operation  of equipment  owned by Owner of equipment  owned by a third
     party to this  Agreement  which is in privity of contract  with Owner whose
     occupancy  of  the  Site  commences   after  the  date  of  this  Agreement
     ("Subsequent  User").  In  the  event  that  such  interference  cannot  be
     eliminated or rectified to Tenant's personal  satisfaction  within five (5)
     business  days of the  receipt  of  notice  by  Owner  from  Tenant  of the
     existence  of  interference   ("Notice  Date"),  Owner  shall  require  the
     Subsequent  User  which is  believed  to be  causing  the  interference  to
     disconnect  utility  service  to their  equipment  until  such  time as the
     interference can be eliminated or rectified to the personal satisfaction of
     Tenant. If said interference  cannot be eliminated or rectified to Tenant's
     personal  satisfaction  within  sixty (60) days of the Notice  Date,  Owner
     shall at the request of Tenant require the Subsequent User which is causing
     the interference to immediately remove its equipment from the Tower and the
     Site or Tenant may at the sole  discretion and option of Tenant,  terminate
     this Agreement upon notice to Owner.

13.  UTILITIES. Owner represents that utilities adequate for Tenant's use of the
     Site are  available.  Tenant may utilize  existing  panels and  connections
     within  or upon the Site for the  connection  of  electrical  utilities  to


                                       10
<PAGE>

     service the Equipment.  Tenant will pay for all utilities used by it at the
     Site.  Tenant  will be  responsible  directly  to the  appropriate  utility
     companies for all utilities required for Tenant's use of the Site. However,
     Owner agrees to cooperate with Tenant, at Tenant's expense,  in its efforts
     to  obtain  utilities  from  any  location  provided  by the  Owner  or the
     servicing utility.  Should electric power be provided by Owner, Tenant will
     install  an  electric  meter and usage will be read by Owner or, at Owner's
     option, by Tenant,  and the cost of electricity used by Tenant will be paid
     by Tenant to Owner  annually  as a payment  separate  from rent and will be
     computed at the then current public  utility rate. In addition,  Tenant may
     at its option and at its expense, install a separate electric meter and pay
     its  electricity  costs  directly  to  the  appropriate   utility  company.
     Temporary  interruption  in the power provided by the  facilities  will not
     render Owner liable in any respect for damages to either person or property
     nor relieve Tenant from fulfillment of any covenant or agreement hereof. If
     any of  Tenant's  communications  Equipment  fails  because  of loss of any
     electrical power, and the restoration of the electrical power is within the
     reasonable control of Owner, Owner will use reasonable diligence to restore
     the  electrical  power  promptly,  but will  have no claim for  damages  on
     account of an  interruption  in electrical  service  occasioned  thereby or
     resulting therefrom.  Notwithstanding the foregoing,  Tenant will cooperate
     with  Owner in  shutting  down  (and  Owner may shut  down) the  electrical
     service to the Site and it's  Equipment in  connection  with any  necessary
     maintenance  operation  conducted for the Site or the  facilities  thereon.
     Owner agrees to give Tenant  reasonable  prior notice,  except in emergency
     situations, which notice may be oral.

14.  TERMINATION  BY TENANT.  Tenant may terminate this Agreement at any time by
     notice to Owner without further liability if (a) Owner fails to have proper
     possession  of the Site or authority to enter into this  Agreement;  (b) in
     the event of a default of any  covenant  or term  hereof by the Owner which
     default is not cured within 60 days of receipt of written notice of default
     (without,  however,  limiting  any other  rights  available  to the parties
     pursuant to other  provisions  hereof);  provided,  that if Owner commences
     efforts to cure the default  within such  period the  non-defaulting  party
     shall no longer be entitled  to declare a default;  (c) if Tenant is unable
     to obtain or  maintain  through no fault of Tenant any  license,  permit or
     other Governmental  Approval necessary to the construction and operation of
     the  Tenant's  Equipment or business;



                                       11
<PAGE>

15.  DEFAULT. If either party is in default under this Agreement for a period of
     (a) 20 business days  following  receipt of notice from the  non-defaulting
     party with respect to a default which may be cured solely by the payment of
     money, or (b) 30 days following  receipt of notice from the  non-defaulting
     party  with  respect  to a  default  which  may not be cured  solely by the
     payment of money,  then,  in either  event,  the  non-defaulting  party may
     pursue any  remedies  available  to it against the  defaulting  party under
     applicable law, including,  but not limited to, the right to terminate this
     Agreement. If the non-monetary default may not reasonably be cured within a
     30 day period, this Agreement may not be terminated if the defaulting party
     commences action to cure the default within such 30 day period and proceeds
     with due  diligence to fully cure the default.

16.  TAXES.  Tenant will be  responsible  for payment of all  personal  property
     taxes,  states sales or use taxes assessed directly upon and arising solely
     from its use of its Equipment on the Site.  Owner will be  responsible  for
     payment  of all  real  property  taxes,  and any  personal  property  taxes
     attributable to the Site and the Tower except Tenant shall pay any increase
     in real estate taxes levied against the Site which are solely  attributable
     to Tenant's use of the Site.  These  additional taxes will be paid to Owner
     by Tenant within twenty (20) business days after written  demand thereof by
     Owner  accompanied  by  copies  of  each  tax  bill,  service  bill  and/or
     assessment notice which is the basis for the demand.

17.  INDEMNITY.  Owner and Tenant each  indemnifies  the other against and holds
     the other harmless from any and all costs (including  reasonable attorneys'
     fees and costs) and claims of  liability or loss which arise out of the use
     and/or occupancy of the Site by the indemnifying party, including,  without
     limitation,  any damage  occurring  outside of the Site in connection  with
     Tenant's  installation  of Equipment.  This indemnity does not apply to any
     claims arising from the gross  negligence or intentional  misconduct of the
     indemnified  party.  Except  for  its  own  acts  of  gross  negligence  or
     intentional misconduct, Owner will have no liability for any loss or damage


                                       12
<PAGE>

     due to personal injury or death,  property damage,  loss of revenues due to
     discontinuance of operations at the Site, libel or slander, or imperfect or
     unsatisfactory  communications  experienced  by the  Tenant  for any reason
     whatsoever.  Owner does hereby agree to indemnify and hold Tenant  harmless
     from any and all losses damages, fines, penalties,  liabilities or costs of
     any kind which may arise from the improper design, maintenance or operation
     of the  Tower or tower  lighting  systems  or which may be  imposed  by the
     Federal Aviation Administration,  Federal Communications  Commission or any
     other  federal,  state or local agency  arising  from the improper  design,
     maintenance or operation of the Tower and the tower lighting  systems.

18.  HAZARDOUS  SUBSTANCES.  Owner  represents  that it has no  knowledge of any
     substance,  chemical or waste (collectively,  "substance") on the Site that
     is identified as hazardous,  toxic or dangerous in any applicable  federal,
     state or local law or regulation. Tenant will not introduce or use any such
     substance  on the Site in violation  of any  applicable  law, or permit any
     discharge  or  release of such  substance  on the Site.  Owner,  its heirs,
     grantees,  successors,  and assigns shall indemnify,  defend, reimburse and
     hold  harmless  Tenant from and against any and all  environmental  damages
     arising from the presence of Hazardous Materials upon, about or beneath the
     Site or migrating  to or from the Site or arising in any manner  whatsoever
     out of the violation of any activities  thereon,  which conditions exist or
     existed prior to or at the time of the execution of this Agreement or which
     may occur at any time in the future.

19.  LIENS.  Tenant will not permit any mechanics,  materialman's or other liens
     to stand against the Site for any labor or material furnished the Tenant in
     connection  with work of any  character  performed on the Site by or at the
     direction of the Tenant. In the event that any notice of lien will be filed
     or given,  Tenant  will,  within  thirty (30) days after the date of filing
     cause the same to be released or discharged by either payment,  deposit, or
     bond.  Owner will be  indemnified  by Tenant  from and  against any losses,
     damages,  costs, expenses,  fees or penalties suffered or incurred by Owner
     on  account  of  the  filing  of  the  claim  or  lien.

20.  CASUALTY  OR  CONDEMNATION.  In the  event of any  damage,  destruction  or
     condemnation  of the Site, or any party thereof,  not caused by Tenant that
     renders the Site unusable or inoperable, Owner will have the right, but not


                                       13
<PAGE>

     the obligation, to provide an alternate location,  whether on the same Site
     or another Site,  or to terminate  this  Agreement  within thirty (30) days
     after the damage, destruction or condemnation.  If Owner does not terminate
     this Agreement: (i) the rent payable hereunder will be reduced or abated in
     proportion  to the actual  reduction or  abatement of use of the Site;  and
     (ii) Owner will make any necessary repairs to the Site caused by the damage
     or destruction  and will be entitled to use any and all insurance  proceeds
     to pay for any repairs.  Owner will in no event be liable to Tenant for any
     damage to or loss of Tenant's  Equipment,  or loss or damage  sustained  by
     reason of any business  interruption  suffered by reason of any act of God,
     by  Owner's  act or  omission,  or Owner's  violation  of any of the terms,
     covenants or conditions of this Agreement,  unless caused solely by Owner's
     intentional  misconduct or gross negligence.

21.  CONFIDENTIALITY.  Tenant  agrees not to discuss  publicly,  advertise,  nor
     publish in any newspaper,  journal, periodical,  magazine, or other form of
     mass media the terms or  conditions  of this  Agreement  or the  underlying
     Ground  Lease.  Doing so shall  constitute a default  under this  Agreement
     immediately.  It is  agreeable  that  Tenant  will not  discuss  terms  and
     conditions with any parties not directly involved with this Agreement.

22.  BANKRUPTCY  AND  INSOLVENCY.  Owner and Tenant  agree  that this  Agreement
     constitutes a lease of non-residential real property for the purposes of 11
     U.S.C.  Section  365(d)(4) or any such successor  provision.

23.  WAIVER OF OWNER'S LIEN.  Owner hereby waives any and all lien rights it may
     have,  statutory  or  otherwise,  in and to the  Equipment  or any  portion
     thereof,  regardless  of  whether  or not same is deemed  real or  personal
     property under applicable laws.

24.  WAIVER OF INCIDENTAL AND CONSEQUENTIAL  DAMAGES.  Owner will not assert any
     claim  whatsoever  against Tenant for loss of  anticipatory  profits or any
     other indirect,  special,  incidental or consequential  damages incurred by
     Owner as a result of the construction, maintenance, operation or use of the
     Site or the  Easement  by Tenant.

25.  MISCELLANEOUS.   (a)  This  Agreement  applies  to  and  binds  the  heirs,
     successors,  executors,  administrators  and assigns of the parties to this
     Agreement; (b) This Agreement is governed by the laws of the State in which
     the Site is located;  (c) If requested by Tenant,  Owner agrees promptly to


                                       14
<PAGE>

     execute and deliver to Tenant a recordable  Memorandum of this Agreement in
     the  form of  EXHIBIT  C;  (d)  This  Agreement  (including  the  EXHIBITS)
     constitutes  the entire  Agreement  between the parties and  supersedes all
     prior  written  and  verbal   agreements,   representations,   promises  or
     understandings  between the parties.  Any amendments to this Agreement must
     be in writing and executed by both  parties;  (e) If any  provision of this
     Agreement  is  invalid or  unenforceable  with  respect  to any party,  the
     remainder of this Agreement or the application of such provision to persons
     other than those as to whom it is held invalid or  unenforceable,  will not
     be  affected  and  each  provision  of this  Agreement  will be  valid  and
     enforceable  to the fullest  extent  permitted by law;  (f) The  prevailing
     party  in any  action  or  proceeding  in  court or  mutually  agreed  upon
     arbitration  proceeding to enforce the terms of this  Agreement is entitled
     to receive its reasonable attorneys' fees and other reasonable  enforcement
     costs and expenses from the non-prevailing  party; and (g) Failure or delay
     on the part of Tenant or Owner to exercise any right,  power,  or privilege
     hereunder will not operate as a waiver  thereof;  waiver of a breach of any
     provision  hereof under any  circumstances  will not constitute a waiver of
     any  subsequent  breach  of the  provision,  or of a  breach  of any  other
     provision of this  Agreement.  The  following  EXHIBITS are attached to and
     made a part of this Agreement: EXHIBIT "A", "B", "C", and "D".


     TENANT:                          OWNER:  SBA TOWERS, INC.

     ____________________________     ______________________________
     By:                              By:
     Title:                           Title:
     Tax No.                          Tax No. 65-0754577
     Address:                         Address: One Town Center Road, 3rd Floor
                                               Boca Raton, FL 33486
                                               Attention: Site Administration

     Date: ______________________     Date: _______________________

     Witness: ___________________     Witness: ____________________

     Witness: ___________________     Witness: ____________________

OWNER NOTARY BLOCK:

STATE OF ________________

COUNTY OF _______________

The  foregoing   instrument  was  acknowledged   before  me  this  ____  day  of
____________, 1999 by __________________, a representative of SBA Towers, Inc. a
Florida  corporation who is personally known to me or produced  ________________
as identification.


                                    ____________________________________
      NOTARIAL SEAL                 (OFFICIAL NOTARY SIGNATURE)
                                    NOTARY PUBLIC-STATE OF _____________


                                    ____________________________________
     My commission expires:         (NAME OF NOTARY)
     ______________________         COMMISSION NUMBER:__________________


                                       15
<PAGE>



TENANT NOTARY BLOCK:

STATE OF _________________ )
                           )
COUNTY OF ________________ )


     The  foregoing  instrument  was  acknowledged  before  me this  ____ day of
____________,   19__   by   ____________________,    ____________________,    of
____________________,   a   ____________________   for  and  on  behalf  of  the
Corporation.


                        _______________________________
                                 NOTARY PUBLIC
                        My Commission Expires: ________


                                    ____________________________________
      NOTARIAL SEAL                 (OFFICIAL NOTARY SIGNATURE)
                                    NOTARY PUBLIC-STATE OF _____________


                                    ____________________________________
     My commission expires:         (NAME OF NOTARY)
     ______________________         COMMISSION NUMBER:__________________

                                       16


SITE I.D.                                     TENANT SITE ID:
SITE NAME:                                    TENANT SITE NAME:

                                    EXHIBIT A
                                SITE DESCRIPTION


Site situated in the City of      , County of        State of         commonly
described as follows:

Legal Description:

Longitude:                 Latitude:

Sketch of Site:





                                       1
<PAGE>



SITE I.D.                                     TENANT SITE ID:
SITE NAME:                                    TENANT SITE NAME:

                                    EXHIBIT B
                           ANTENNA AND EQUIPMENT LIST


ANTENNA(S):
         Quantity:
         Type:
         Manufacturer
         Model:
         Dimensions:
         Weight:
         Mounting: ____________ rad center
                   Orientation:______(degree), ______ (degree) & ______(degree)
         Cable:
                  Number of Lines:
                  Type:
                  Size:

DISH:
         Quantity:
         Manufacturer:
         Model:
         Dimensions:
         Weight:
         Mount:
                  at       ' height level.
                  Orientation
         Cable/Type Mount:

GPS Receiver:
         Quantity:
         Manufacturer:
         Model:
         Dimensions:
         Mount Location:
         Cable/Mount:

GROUND SPACE REQUIREMENTS:

         Tenant provided Shelter
                  Dimensions:
                  Type Shelter:


                                       2
<PAGE>



SITE I.D.                                           TENANT SITE ID:
SITE NAME:                                          TENANT SITE NAME:


                             Existing Shelter Space
                               Dimensions Needed:

IF EXISTING SPACE IN OWNER'S  SHELTER IS BEING USED,  PLEASE  PROVIDE  EQUIPMENT
SPECIFICATIONS:


 Transmitter
          Quantity:
          Manufacturer
          Model:
          Power Output (Watts):

         Transmitter Cabinet
                  Quantity:
                  Manufacturer
                  Model:
                  Dimensions:
                  Weight

FREQUENCIES:

ERP:





                                       3
<PAGE>



SITE I.D.                                           TENANT SITE ID:
SITE NAME:                                          TENANT SITE NAME:

                                    EXHIBIT C

                      MEMORANDUM OF ANTENNA SITE AGREEMENT
                      MEMORANDUM OF ANTENNA SITE AGREEMENT

This  memorandum  evidences  that a lease was made and  entered  into by written
ANTENNA SITE AGREEMENT dated , between SBA Towers,  Inc., a Florida Corporation,
"Owner  ________________,  a ____________  Corporation,  "Tenant," the terms and
conditions of which are incorporated herein by reference.

Such  Agreement  provides  in part that  Owner  leases to Tenant a certain  site
"Site"  located at , City of , County of , State of , within the  property of or
under the control of Owner which is described in Exhibit A attached hereto, with
grant of easement for unrestricted  rights of access thereto and to electric and
telephone  facilities  for a term of five (5) years  commencing on which term is
subject to three (3) additional five (5) year extension periods by Tenant.

IN WITNESS WHEREOF,  the parties have executed this Memorandum as of the day and
year first above written.

OWNER:

______________________________              Address:
By:                                         One Town Center Road, 3d Floor
Title:                                      Boca Raton, FL 33486
Tax No: 65-0754577                          Date:_______________________





                                       4
<PAGE>



OWNER NOTARY BLOCK:

STATE OF ____________                       COUNTY OF ____________

The foregoing instrument was acknowledged before me this ____ day of __________,
1999, ________________,  ________________, a representative of SBA Towers, Inc.,
a  Florida,  who is  personally  known  to me or  produced  ________________  as
identification.


                  NOTARIAL SEAL       ____________________________________
                                      (OFFICIAL NOTARY SIGNATURE)
                                      NOTARY PUBLIC-STATE OF _____________


                                      ____________________________________
         My commission expires:       (NAME OF NOTARY)
         ___________________          COMMISSION NUMBER:__________________

Witness: __________________________

         __________________________
         Print Name

Witness: __________________________

         __________________________
         Print Name





                                       5
<PAGE>



SITE I.D.                                      TENANT SITE ID:
SITE NAME:                                     TENANT SITE NAME:

                 MEMORANDUM OF ANTENNA SITE AGREEMENT CONTINUED

TENANT:

__________________________                  Address
By:
Title:
Tax No.                                     Date:___________________


TENANT NOTARY BLOCK:

STATE OF ____________                       COUNTY OF ______________

The  foregoing   instrument  was  acknowledged   before  me  this  ____  day  of
______________,   ______________  by  ________________,   ________________,   an
individual or a representative of ______________,  a ______________ Corporation,
or by  ____________,  partner  (or  agent)  on  behalf  of  ________________,  a
partnership  who  is  personally  known  to  me  or  produced   ____________  as
identification.


                  NOTARIAL SEAL     ____________________________________
                                    (OFFICIAL NOTARY SIGNATURE)
                                    NOTARY PUBLIC-STATE OF _____________

                                    ____________________________________
         My commission expires:     (NAME OF NOTARY)
         ___________________        COMMISSION NUMBER:__________________

Witness: _______________________

         _______________________
         Print Name

Witness: _______________________

         _______________________
         Print Name





                                       6
<PAGE>



SITE I.D.                                      TENANT SITE ID:
SITE NAME:                                     TENANT SITE NAME:


                                    EXHIBIT D

                    MINIMUM SITE INSTALLATION, OCCUPANCY AND
                   MAINTENANCE REQUIREMENTS AND SPECIFICATIONS


PRE-INSTALLATION STANDARDS

1. PRIOR TO  INSTALLATION,  Tenant must provide  Owner with  complete  plans for
approval,  including list of proposed equipment and subcontractors.  No work may
be performed  until  approval has been given and all criteria have been met. All
equipment must be placed in approved  locations only, and Owner must approve any
changes before the installation  begins. The Owner or its  representative  shall
have the right to be on site during any work on the Site. Owner to provide price
quote for installation services based on Tenant's scope of work.

INSTALLATION

2.  (a)    The following minimum protective devices must be properly installed:

          (1)  Lightning  arrestors  in  feedline  at wall  feedthru  ports (SBA
               multi-tenant  buildings).   (PCS  providers  install  jumpers  to
               extend/connect to cabinet like enclosures).

          (2)  Surge protectors in any AC & phone line circuit.

          (3)  Transmitter RF shielding. (Must be in place during operation)

          (4)  Isolator/harmonic filter. (Must be in place during operation)

          (5)  Duplexer  or cavity  bandpass  filter.  (Must be in place  during
               operation)

     (b)  All  equipment,  including  transmitters,   duplexers,  isolators  and
          multicouplers,  must be housed in a metal cabinet or rack mounted.  No
          control  stations or  inverted  transmit/receive  frequency  pairs are
          allowed on repeater sites.

     (c)  All   transmission   lines   entering   the   shelter   must  be  1/2"
          Heliax/Wellflex or better via a wall feedthru plate and must terminate
          in a properly installed lightning arrestor with an ID tag on both ends
          of the  line.

     (d)  Solid outer shield cable such as Superflex or Heliax/Wellflex  must be
          used for all intercabling outside the cabinet.  Under no circumstances
          will the use of foil  shielded  or  braided  RF cable  (e.g.;  RGB) be
          permitted  outside  the  cabinet  except  for RG-6 quad  shield  cable
          installed on satellite  receive only systems.

     (e)  All  antenna,  power and phone  cables  will be  routed  and  properly
          supported to the base  station in a neat manner using routes  provided
          for that purpose. Tenant will provide individual Transient (SAD) surge
          protection  to each  circuit  used.  All phone  lines  will have (SAD)
          transient surge protection installed. All wiring and installation will
          be by means of clamping or strapping  and in no event will any members
          or other parts of the tower be drilled,  welded,  punched or otherwise
          mutilated  or altered.



                                       7
<PAGE>

     (f)  All  Tenants  are to  obtain  power  from the  power  panel  and/or AC
0          receptacle  provided  for  their  specific  use.

     (g)  All outside RF equipment  cabinets must be grounded to the site ground
          system  using  #2  solid  tinned  wire  with  cadweld,  silver  solder
          connections, or 2 hole lugs with Burndy type compression fittings. All
          inside RF  equipment  cabinets  must be  grounded  to the site  ground
          system using #2, or #6 green jacketed stranded wire with silver solder
          connections, or 2 hole lugs with Burndy type compression fittings.

     (h)  All  antenna  lines  will be  electrically  bonded to the tower at the
          antenna and at the bottom of the tower using  grounding kits installed
          per  manufacturer  specifications  and all  antenna  brackets  must be
          pre-approved.  All  antenna  lines  entering  the Site  will have COAX
          center pin  lightning  protection  installed  within two feet from the
          entry  port and  grounded  to  master  ground  bar in the Site  ground
          system.

     (i)  All equipment  cabinets  will be  identified  with a typed label under
          plastic on which the Tenant's  name,  address,  24 hour phone  number,
          call sign, and frequencies will be inscribed, in addition to a copy of
          Tenant's FCC license.

     (j)  Monitor  speakers will be disabled  except when  maintenance  is being
          performed.  All antenna  lines will be tagged  within 12 inches of the
          termination  of the feeder cable at both ends,  at the entrance to the
          building,   at  repeater  or  base   station   cabinet,   and  at  the
          multicoupler/combiner ports.

     (k)  All ferrous  metals  located  outside of the  building or on the tower
          will be either stainless steel or hot dipped  galvanized,  not plated.
          Painted  towers will  require the painting of feedlines by the Tenant,
          unless  installed  by  Owner,  prior to or  before  completion  of the
          install.  All transmission  lines are to be secured with factory hoist
          grips  every  150' and  secured  to the  tower or  cable  ladder  with
          stainless steel and/or hot dipped galvanized  hardware.  Plastic wraps
          and/or bandit type hangers will not be accepted.

GENERAL

3.   Tenant must  comply with any  applicable  instructions  regarding  any Site
     security system.

     (a)  Gates will remain  closed at all times unless  entering or exiting the
          premises.  When leaving the shelter,  ensure that all doors are locked
          and,  if  there is a  security  system,  it is  armed.

     (b)  Any tower elevator may be used only after receiving proper instruction
          on its use,  signing a waiver  and  receiving  authorization  from the
          Owner.

     (c)  This  Agreement  does  not  guarantee   parking  space.  If  space  is
          available,  park only in the  designated  areas.  Do not park so as to
          block any  ingress  or egress  except as may be  necessary  to load or
          unload  equipment.  Parking is for  temporary use while working at the
          Site.

     (d)  Do not adjust or tamper with  thermostats or HVAC systems.

     (e)  Access to the shelter roof is  restricted  to  authorized  maintenance
          personnel.


                                       8



                      ATTACHMENT C TO MASTER SITE AGREEMENT


Recording requested by and when
recorded return to:  Deborah L. Martinez
SBA TOWERS, INC. / BTS Leasing Dept.
One Town Center Road, 3rd Floor
Boca Raton, Florida 33486
(800) 487-7483 ext. 238

RE:  Site Lease
Recorded:____________________
Bk#:__________    Pg#:__________


                         SUBORDINATION.NON-DISTURBANCE
                            AND ATTORNMENT AGREEMENT


     THIS AGREEMENT (this "Agreement"), dated as of ______________, 1999, by and
between LEEMAN COMMERCIAL PAPER,  INC., as Administrative  Agent for the Lenders
parties to that  certain  Amended  and  Restated  Credit  Agreement  dated as of
February 5, 1999,  with an address of 3 World  Financial  Center,  New York, New
York, 10285, ("Lender"), and ____________________, a ____________________ having
its     principal     office    and    place    of    business     located    at
______________________________("Tenant").

                             PRELEMINARY STATEMENT:

     A.  Lender has made or  intends to make a loan or loans (the  "Loan") to or
for the benefit of SBA Towers, Inc., a Florida corporation  ("Owner") secured by
a leasehold  interest in certain real property more fully described on the metes
and bounds legal description which is attached hereto,  made a part hereof,  and
labeled Exhibit "N" and all improvements thereon and appurtenances  thereto (the
"Property").

     B. Lender has  required  the Loan to be secured to be secured by a mortgage
and security agreement (the "Mortgage") on the Property.

     C.  Owner and  Tenant  will enter into a site  lease,  (the  "Lease")  with
respect to certain premises (the "Premises') which are part of the Property,  as
more particularly set forth in the Lease.

     D.  Owner has  assigned  or is to  assign,  pursuant  to the  Mortgage  and
documents related thereto,  all of its right, title and interest in the Property
and the Lease and the rent payable thereunder to Lender as security, inter alia,
for the  performance  of its  obligations  made in connection  with the Loan.



                                       1
<PAGE>

     E.  Therefore,  in  consideration  of the mutual  benefits  accruing to the
parties hereto and other valuable consideration,  the receipt and sufficiency of
which are hereby acknowledged, Lender and Tenant hereby agree as follows:

          1. SUBORDINATION.  Notwithstanding  anything to the contrary set forth
in the Lease, but subject to the express provisions of this Agreement, the Lease
and the leasehold  estate created thereby shall at all times remain  subordinate
and inferior to the Mortgage and the lien thereof,  and to any and all renewals,
modifications, consolidations, replacements and extensions thereof.

          2.  NON-DISTURBANCE.  So long as Tenant is not in  default  (after the
expiration  of all periods  afforded to Tenant during which Tenant has the right
to cure any  default) in the payment of rent,  additional  rent or other sums or
charges now or hereafter  payable under the Lease,  or in the performance of any
of the terms,  covenants or conditions of the Lease, Tenant shall not, by reason
of foreclosure of the Mortgage,  acceptance of a deed in lieu of foreclosure, or
the exercise of any remedy  provided in the  Mortgage,  be disturbed in Tenant's
use,  occupancy and quiet enjoyment of the Premises during the term of the Lease
or any extension thereof set forth in the Lease, and Tenant shall have the right
to exercise  all  renewal  terms set forth in the Lease in  accordance  with the
terms of the Lease. In the event of a foreclosure of the Mortgage, acceptance of
a deed in lieu of  foreclosure,  or the  exercise of any remedy  provided in the
Mortgage,  Lender shall  recognize and confirm the validity and existence of the
Lease,  and Tenant's  right to remain in occupancy of the Premises and the Lease
will  continue  in full  force  and  effect  and  Tenant  will have the right to
continue  the Use  permitted  by the Lease and  occupancy  of the  Premises  and
operation of the Tenant's equipment pursuant to the provisions of the Lease.

         3.  ATTORNMENT.  Upon the  transfer  of the  Premises  to Lender or its
successors or assigns, whether through foreclosure,  deed in lieu of foreclosure
or otherwise,  Tenant shall attorn to such  transferee as the landlord under the
Lease.  Said  attornment  shall be  effective  and  self-operative  without  the
execution of any further  instruments  upon the  transferee's  succeeding to the
interest of the  landlord  under the Lease.  Tenant and Lender  shall,  however,
confirm the  provisions  of this  paragraph in writing upon request by either of
them.

          4. MISCELLANEOUS.

               (a) This  Agreement  shall  inure to the  benefit of the  parties
hereto, their successors and assigns;  provided,  however,  that in the event of
the  assignment  or transfer  of the  interest of Lender,  all  obligations  and
liabilities of Lender under this Agreement  shall  terminate,  and thereupon all
such  obligations and liabilities  shall be the  responsibility  of the party to
whom Lender's interest is assigned or transferred.

               (b) This  Agreement is the whole and only  agreement  between the
parties hereto with regard to the subject matter hereof.  This Agreement may not
be  modified  in any manner or  terminated  except by an  instrument  in writing
executed by the parties hereto.



                                       2
<PAGE>

               (c) This Agreement shall be deemed to have been made in the state
where the Property is located and the validity,  interpretation  and enforcement
of this Agreement shall be determined in accordance with the laws of such state.

               (d) In the event any legal action or  proceeding  is commenced to
interpret  or  enforce  the  terms  of,  or  obligations  arising  out of,  this
Agreement, or to recover damages for the breach thereof, the party prevailing in
any  such  action  or   proceeding   shall  be  entitled  to  recover  from  the
non-prevailing party all reasonable attorneys' fees, costs and expenses incurred
by the prevailing party.

               (e) Any notices or  communications  required or  permitted  to be
given or made  hereunder  shall be deemed to be so given or made when in writing
and delivered in person or sent by United States  registered or certified  mail,
postage prepaid, or by nationally recognized overnight courier service, directed
to the parties at the following  addresses listed above or to such other address
as such party may from time to time  designate  in  writing to the other  party.
Notices or  communications  mailed in the U.S. mail shall be deemed to be served
on the third business day following mailing,  notices or communication served by
hand or by overnight courier shall be deemed served upon receipt.

     IN WITNESS WHEREOF,  this Agreement has been signed and delivered as of the
date and year first above set forth.

                                     LENDER:
                                     LEHMAN COMMERCIAL PAPER, INC.,
                                     as Administrative Agent

Witnesses                            By:_______________________________

__________________________           Print:____________________________
Sign/Print Name                      Its:______________________________

__________________________
Sign/Print Name                      TENANT:

Witnesses                            By:_______________________________

__________________________           Name:_____________________________
Sign/Print Name                      Title:____________________________

__________________________
Sign/Print Name

Attest:___________________                 [AFFIX CORPORATE SEAL]
Name: ____________________
Title:____________________



                                       3
<PAGE>



LENDER:

STATE OF ______________

COUNTY OF _____________


The  foregoing   instrument  was  acknowledged   before  me  this  ____  day  of
____________,  1999, by  __________________________  as  ____________________ of
____________________  a  ____________________,  on  behalf  of the  corporation.
He/She  is  personally  known  to me or  has  produced  ____________________  as
identification.


(AFFIX NOTARIAL SEAL)            __________________________________________
                                 (OFFICIAL NOTARY SIGNATURE)
                                 Notary Public - State of _________________

                                 __________________________________________
                                 (Printed, Typed or Stamped name of Notary)

                                 Commission Number:________________________



                                       4
<PAGE>

TENANT:

STATE OF _______________

COUNTY OF ______________

     I, a Notary  Public  for said  County  and State,  do hereby  certify  that
__________________________   personally   appeared   before   me  this  day  and
acknowledged  that he/she is ____________  Secretary of  ____________________  a
____________________   and   general   partner   of   ____________________,    a
____________________,  and that by authority  and as the act of the  corporation
and on behalf of the  partnership,  the foregoing  instrument  was signed in its
name by its __________  President,  sealed with its corporate seal, and attested
by him/her as its __________ Secretary.


(AFFIX NOTARIAL SEAL)             ____________________________________
                                  (OFFICIAL NOTARY SIGNATURE)
                                  Notary Public - State of ___________

                                  ____________________________________
                                  (Printed, Typed or Stamped name of Notary)

                                  Commission Number:__________________




                                       5
<PAGE>



                                   EXHIBIT "A"

                        LEGAL DESCRIPTION OF THE PROPERTY






                                       6
<PAGE>
                                 FIRST ADDENDUM
                                       TO
                              MASTER SITE AGREEMENT

     THIS FIRST  ADDENDUM  TO MASTER  SITE  AGREEMENT  ("Addendum")  is made and
entered  into  this  _____ day of April,  2000 by and  among  SBA  Towers,  Inc.
("SBA"),  Bright Personal  Communications  Services,  LLC ("Bright") and Horizon
Personal  Communications,  Inc.  ("Horizon")  Bright and Horizon may hereinafter
collectively referred to as "Lessee".

     WHEREAS,  SBA and Horizon  entered into that certain  Master Site Agreement
("Horizon MSA") dated as of August 17, 1999;

     WHEREAS,  SBA and Bright  entered into that certain  Master Site  Agreement
("Bright MSA") dated as of the day of October, 1999 ;

     WHEREAS, SBA and Lessee both wish to modify the Horizon MSA and Bright MSA.

     NOW  THEREFORE,  for  good  and  valuable  consideration  the  receipt  and
sufficiency of which are hereby acknowledged,  SBA, Bright and Horizon do hereby
agree as follows:

     1.  Secured  Financing  Addendum.  SBA and Lessee  wish to modify  both the
Horizon MSA and Bright MSA to incorporate the following provisions:

          Financing.  Lessee  may,  upon  notice  to SBA,  mortgage  or  grant a
     security  interest in this MSA and the  Equipment,  and may assign this MSA
     and the Equipment to any such  mortgagees or holders of security  interests
     including their successors and assigns (hereinafter  collectively  referred
     to as "Secured Parties").  In such event, SBA shall execute such consent to
     leasehold  financing  as may  reasonably  be required  by Secured  Parties.
     Provided that SBA has been given  written  notice of the name and addresses
     of the Secured  Parties by Lessee,  SBA shall  notify  Lessee and  Lessee's
     Secured Parties simultaneously of any default by Lessee and to give Secured
     Parties the same right to cure any  default as Lessee  except that the cure
     period  for any  Secured  Party  shall not be less  than 10 days  after the
     receipt of the default notice. If a termination, disaffirmance or rejection
     of the MSA pursuant to any laws  (including  any  bankruptcy  or insolvency
     laws) by Lessee shall  occur,  or if SBA shall  terminate  this MSA for any
     reason,  SBA will give to the Secured Parties prompt notice thereof and SBA
     will give the Secured  Parties the right to enter upon the  Property or BTS
     site, as  applicable,  during a 30-day period  commencing  upon the Secured
     Party's  receipt of such notice for the purpose of removing any  Equipment.
     Upon written  request from Lessee,  SBA shall execute and deliver a written


                                       1
<PAGE>

     instrument  in  recordable  form   acknowledging  the  assignment  and  the
     foregoing agreements of SBA.

     2.  Consent  to  Assignment.   Notwithstanding  anything  to  the  contrary
contained  in this MSA,  SBA shall have the right to assign this MSA and any SLA
to an Affiliate of SBA, and upon such assignment, SBA shall be released from any
and all obligations  under the assigned MSA or SLA,  provided that such assignee
assumes all of SBA's obligations under such assigned agreement in writing at the
time of the  assignment.  For  purposes  of this MSA,  "Affiliates"  shall  mean
companies which control are controlled by, or under common control with SBA. For
purposes of this MSA, the word "control"  shall mean the ownership,  directly or
indirectly,  of the power to direct or cause the direction of the management and
policies of an entity,  or the power to veto major policy  decisions of any such
entity,  whether  through the  ownership  of voting  securities,  by contract or
otherwise.

     3. No Other Modifications.  The Horizon MSA and the Bright MSA shall remain
the entire  agreement  and  understanding  of SBA and Lessee with respect to the
subject  matter  thereof  except as  modified  by this  Addendum,  and except as
specifically  altered and amended herein, the Horizon MSA and the Bright MSA are
hereby ratified and confirmed in all respects, are in full force and effect, and
have not otherwise been amended, modified, extended or renewed, whether verbally
or in writing.

     IN WITNESS WHEREOF,  SBA, Horizon and Bright have executed this Addendum as
of the date and year first above written.

SBA TOWERS, INC.


Attest:________________________

Title:_________________________


HORIZON PERSONAL COMMUNICATIONS, INC.


Attest:________________________

Title:_________________________


BRIGHT PERSONAL COMMUNICATIONS SERVICES, LLC

                                       2
<PAGE>

Attest:________________________

Title:_________________________