(perhaps off topic, but) Microwave Towers

Hi Folks,

I find myself driving down Route 66. On our way through Arizona, I was surprised by what look like a lot of old-style microwave links. They pretty much follow the East-West rail line - where I'd expect there's a lot of fiber buried.

Struck me as somewhat interesting.

It also struck me that folks here might have some comments.

Miles Fidelman

There’s a lot less backhoe fade with microwave. :wink:

Kidding aside, I’m sure there are plenty of scenarios where microwave makes better sense than fiber especially since it’s a lot easier to clear right of way through the air.

Side gig has me maintaining a satellite system. Yes that still makes sense. As part of that I have a service that monitors people applying for microwave transmitters within a few hundred miles. You’d be surprised how many links are applied for every month.

I’m not 100 percent positive, but from what I recall in my time down that way as a contractor for $major_railroad, I believe they are or were used by the railroad for their communication links. They may not necessarily be in service any longer though. Probably one of those instances where “if it ain’t broke, don’t fix it.” In other words, if the tower isn’t falling down or a hazard, why spend the money to go remove it?

I know as recently as 2003, BNSF Railway was still using and upgrading microwave infrastructure in Chicago.

http://reference.newslink.com/current-pubs/CHIC/CHIC0304.pdf (see page 2)

> I find myself driving down Route 66. On our way through Arizona, I was surprised by what look like a lot of old-style microwave links. They pretty much follow the East-West rail line - where I'd expect there's a lot of fiber buried.

Could they be a legacy of the Southern Pacific Railroad Internal Network Telecommunications,
now known under the acronym SPRINT?
  - Brian

Not along Route 66 in Arizona. That generally parallels BNSF Railway, formerly the Santa Fe down there. Southern Pacific followed Interstate 10 much further south.

We had a ton of point to point wireless customers at 120E Van Buren out to South Mountain. About 10 years ago there was a significant shortage of fiber outside of Phoenix. You choices were SRP and Cox for the most part and SRP at that time had a very limited fiber network. They were actually the only company that offered dark Fiber out to Chandler when that campus first got built.

Robert DeVita
Managing Director
c. 469-441-8864
e. radevita@mejeticks.com

Is it possibly AT&T's old network?

This network runs through our service territory, too. The horns are distinctive.


Did it follow this route?



Looks like it!
Did it follow this route?



Too far North. BSNF territory.

Most of these horns are for 6GHz. I have had friends that have
"appropriated" some of them by adding a waveguide to N adapter and use
them for the 5.8GHz ISM band with some minor aiming. Kick ass antenna gain.



I find myself driving down Route 66.� On our way through Arizona, I
was surprised by what look like a lot of old-style microwave links.�
They pretty much follow the East-West rail line - where I'd expect
there's a lot of fiber buried.

Not a lot of fiber. If there was, the following wouldn't be needed:

There *are* a number of fiber builds in the area, but none of them are a
coherent build across the region.

HFT or any low-latency app is such a scenario (0.999c through air being 50% faster than 0.66c though fiber), but that region doesn't fit for that use.

I was going to say... in my experience (I've been to a lot of the
Arizona electronics sites, having grown up around broadcasting) that
most of the microwave equipment in use was for Bell. That was by far
the most populous tower on any mountain top. The broadcasters don't
send their signals anywhere but either from downtown to the transmiter
or in some cases from the big town to a small town to feed a local low
power transmitter (like 5kw VHF as opposed to the normal 100kw).
Anything else was Satelite. I know the railroad did some wireless
(Sprint's towers were also quite densely packed with directional
horns) but a lot of their communication for rail signaling was
hardwire as far as I was aware.


No idea where you were at, but lots of big companies have done microwave and lots of new companies do microwave.


MCI was founded as Microwave Communications, Inc. on October 3, 1963 with John D. Goeken being named the company's first president. The initial business plan was for the company to build a series of microwave relay stations between Chicago, Illinois and St. Louis, Missouri. The relay stations would then be used to interface with limited-range two-way radios used by truckers along U.S. Route 66 or by barges on the Illinois Waterway.


Southern Pacific maintained an extensive microwave communications system along its rights-of-way that the railroad used for internal communications.

AT&T had a bunch and I think a couple sites are still active: http://long-lines.net/

Western Union had a microwave network as well.

Lots of companies build microwave for internal communications. Rail and utility companies are big here.

All of the cell companies do some microwave in their more rural areas.

Lots of independent ISPs use microwave to build their entire network.

Microwave radios are the things that break the mold of the incorrect
assumption that just because it doesn't make sense to put up more wires to
a house you can't have more than one provider. Considering that we've
deployed a few wireless systems with less latency, jitter, and downtime
than the local incumbent DOCSIS provider. In fact the greatest benefit to
wireless microwave systems is the fact that they do not need to follow the
right of way. Where wireline and fiberoptics must go through more hubs to
get from side of town to the other, wireless is a point to point system
with latencies+jitter sub 400 microseconds.

No matter how great the incumbent fiber/dsl/coaxial network becomes, there
will always be new microwave links going up. For their biggest strengths
there's no replacement.
Now, their weaknesses may be many, and may be apparent, their stengths just
outweigh those.

As Mike points out, there are a lot of us doing fixed-wireless / microwave

We have our own industry. See: http://wispa.org/

Also worth mentioning that AT&T Canada originated with the Canadian Pacific

CP Railway and Unitel --> AT&T Canada --> Allstream --> MTS-Allstream -->

I have a GIS dataset with about 90% of the most important hilltop and
mountaintop tower sites in WA, BC, OR and ID. There is a ton of stuff out
there and operational.