Do communication towers have a limited future by virtue of satellites
taking over their present function? I am told that the present
extensive tower
infrastructure will be used for decades to come. What is the
consensus of educated opinion and who is offering these opinions? I am
asking this question as part of due diligence for investment purposes.

Thank you.

GL McGowan

lm7-ga,

Thanks for contacting Google Answers.

Very interesting question.  There is often contention on this in the
communications engineering community.  The short-answer consensus is
"No", and here's why.

First and foremost, as funkywizard suggests, the cost of launching a
satellite is significant compared to the cost of implementing a
communications tower.  This is becoming the prevalent issue, as the
cost of communications towers is going down significantly due to
improvements in engineering (communications towers able to look more
like natural features or even portions of buildings, as opposed to
large "tower infrastructure" as has been traditional).

Secondly, the capacity of satellites is limited compared to
communications towers.  For example, the Iridium satellite system,
consisting of 72 satellites, was only capable of the wireless system
in New York City when it was launched.  The cost was something like
eight or nine billion.

Third, there are a limited number of satellite slots available and the
regulatory and governmental hurdles required to launch a number of
them is significant.

Fourth and finally, there is a latency associated with satellite
communications that is extremely hard to compensate for and usually
not suitable for ubiquitous communications (biggest driver right now).

Communications towers are often referred to as candidates for
replacements by satellites.  Current technology doesn't support this
view.  A more likely replacement for a communications tower
infrastructure might be the "orbiting plane" idea, popularized by
groups like SkyTower
(http://www.business2.com/articles/mag/0,1640,44588,FF.html).  In
addition, what we are seeing today is a movement towards using
communications towers put up by cellular or other wireless companies
as things that are becoming even more commercial and easy-to-add to. 
Phased-array 802.11(B) is right around the corner, and this type of
ubiquitous access can't be supported by satellites at this time.  It
appears to be a big driver in the development of additional wireless
infrastructure, as cellular builds are slowing year-over-year as the
footprint becomes greater and as new technology allows increased
capacity on existing resources.
 
Examples of companies in the communications tower space:

Pinnacle Towers (http://www.pinnacletowers.com)
SBA Communications (http://www.sbasite.com/)

Suggest you may want to take a look at a copy of Kagan's Comm Tower
Databook (http://www.kagan.com/cgi-bin/pkcat/tow02_toc.html).

If I can offer more information, please do not hesitate to let me
know.

Search methodology:

Google searches on (sometimes combinations):

communications tower value
Pinnacle Holdings (http://finance.yahoo.com/q?s=BIGT&d=v1)
communications tower investment
"communications tower" vs satellite
iridium cost
satellite capacity communications tower
and other derivatives.

Thanks and Best of luck,
arimathea-ga

Provided accurate base information to support a proper position in
response to the question.
LM

Researchers may want to investigate the cost of launching a satellite
(tens of millions) vs the cost of erecting a tower (hundreds of
thousands).