A quick history and explanation of microwave communication in telecom networks

This page will give you a general background of microwave radios. If you have a specific project in mind, these pages will be more useful:

Specific Project Links

Read all of our microwave articles: Microwave Knowledge Base

Microwave Communication Overview

Microwave communication is a method of wirelessly sending data. It is very similar to radio technology. Microwaves are right next to radio waves on the electromagnetic spectrum.

What are Microwave Communications used for?

Modern microwave systems are used in telephone networks (both wireless and wireline) and ISPs. They're used by power utilities to remotely manage the power grid. They're used by public safety agencies (ex. police, fire) for remote monitoring and management.

Many industries used microwave, and they do it for one important reason: it can transmit data over long distances without physical wires.

This is common in rural mountainous regions, where installing physical transmission lines is difficult and expensive. Microwave systems minimize installations and maintenance, as a signal microwave tower can transmit data across dozens of miles.

Why are Microwave Transmitters mounted on towers?

Just like visible light, microwaves are blocked by obstacles. They need a clear path to reach their destination. Mounting transmitters and receivers high on a tower offers a clear line-of-sight to the next tower. Also, taller towers reduce the impact of the Earth's curvature. Taller towers can be spaced farther apart and still see one another.

How is Digital Microwave different from Analog?

Microwave communication has been around for a long time.

Just like most other communication technologies, microwaves had a digital revolution. What that means for you today is that only older microwave transmitters are analog.

Special workarounds are required for them to carry modern digital data. As time continues to progress, analog microwaves will grow increasingly rare.

Microwave communication is the sending of signals via radio using a series of microwave towers. It's a form of "line of sight" communication. There must be nothing obstructing transmission of data between these towers. That's why microwave towers are frequently placed on mountaintops. When positioned on a tall peak, a tower has lines of sight to valleys below on all sides and to other mountaintop towers. The increase elevation also reduces the impact of the Earth's curvature on line of sight.

When was it Developed?

The technology used for microwave communication was built in the early 1940's by Western Union. The first microwave message was sent in 1945. It traveled from NY to PA. Following this success, microwave became the most commonly way to provide service.

With new satellite and cell technologies, fiber optics has become more common than microwave transmissions.

However, microwave gear is still used at many remote sites where fiber cabling cannot be installed cheaply.

Is Microwave Communication Analog or Digital?

Microwave communication uses analog and digital formats. While digital is the most advanced form, both are useful.

Are Analog Microwave Communications expensive?

Analog microwave communication may be cheapest option for your tower sites. It's paid for and in service; if you have older microwave equipment, it's most likely analog. To avoid having to retrain your staff or encounter new issues, you may want to retain your current analog microwave gear.

How does Digital Microwave Decrease System Poll?

Digital microwave comms use more advanced, more reliable technology. It is much easier to find equipment to support this transmission method because it's newer. Because it has a higher bandwidth, you can transmit more data using more verbose protocols. The increased speeds will also decrease the time it takes to poll your microwave site equipment. This more reliable format provides for more reliable reporting with advanced communication equipment, while also allowing you to bring in your LAN connection when it becomes available at the site.

Microwave System Monitoring is a Necessity

Digital or analog, monitoring microwave communication equipment is considered a mission critical operation. Monitoring online connectivity is a 24/7 operation that requires dedicated monitoring.

But most importnatly, your customers should never be the first to tell you about a network outage.

You also have other concerns not directly related to microwave. Consider the risk of copper theft. Most microwave sites are very remote. Sure, a typical equipment failure is a problem, but fixing it quickly minimizes the revenue impact. A copper theft event is a much bigger problem. First, it probably takes a long time to fix. Second, replacing (and paying labor costs to reinstall) copper is expensive. This is equally true for any other kind of theft or vandalism. You lose revenue AND skyrocket costs at the same time.

Also think about the required aircraft obstruction lighting for your towers. To avoid FCC/FAA fines for non-compliance, you have to keep your lights online. Any lighting failure must be reported promptly to minimize your risk of fines and liability.

It's problems like these that necessitate a remote monitoring system to instantly notify you of microwave transmission failures.

Deploy an RTU at Your Site to Protect Your Critical Microwave Communications

A network alarm monitoring system is composed of a fleet of remote telemetry units, or "RTUs", which collect alarms from your microwave communication equipment and forward them to your alarm master.

These remotes are a critical piece of your monitoring system because they provide your alarm master with the information it needs to notify you of an outage via email or text message.

No matter what RTU you choose, you'll be in better shape than if you use "embedded" monitoring built into your microwave system. It's never good to let equipment monitor itself (what happens when it fails?), but there's another problem, too. Embedded systems are big trouble when it's time to upgrade your transport.

Imagine that your LAN has expanded or you're upgrading to new microwave hardware. What happens to your monitoring? Will you purchase a brand new monitoring system for every site? Will you keep your old transport gear powered up purely for its telemetry? These are painful options. Dedicated RTU hardware eliminates this problem.

Don't think that this can't happen to you. I spend a lot of time speaking with network owners on the phone and at seminars, and this is a very common theme. Many people are forced into a hunt for monitoring when they upgrade their microwave transport network. Don't wait until you're in a tight spot. Set up your monitoring system on your terms and on your timetable.

What should I look for in a RTU for microwave transmission sites?

There are plenty of RTU manufacturers out there, but most of them won't be appropriate for your microwave facilities. Some will be built for corporate IT environments in air-conditioned data centers, not remote industrial mountaintop sites. Others won't have the right transport or protocol you need. Here's a quick RTU tutorial for microwave transmission sites:

Power Input Voltage

What power voltage is available at your microwave transmission site? Hint: It's probably not 110 VAC, making "IT" RTUs a poor choice. Look for an RTU with native -48 VDC, +24 VDC, or whatever you need it to support.


Form Factor

Do you have rack space available? Is it 19" or 23" wide? If the rack is full at a site, can you mount on a wall? What about DIN rails inside a small cabinet. Can you mount this RTU on a DIN rail? You need an RTU that you can physically accommodate.



How many contact closures do you have to monitor? How many battery voltages? Will a single temperature sensor work, or do you need to mount several at different locations? You need monitoring hardware that can cover all the critical equipment and environmental conditions at your microwave site.



Do you have gear that can be controlled with a contact closure? If so, you'll want a control relay output on your RTU to cover each one. Do you have gear that gets jammed up and needs a routine power cycle? Higher-amp relays (ex. 10A) can remotely toggle power to force a reboot. Find an remote alarm device with the right outputs



Do you have older analog microwave transmission gear that requires a 202 or FSK modem? Do you need a serial connection? Do you have IP overhead channels on your digital microwave? All of these potential scenarios need a different RTU transport.



Dictated by your transport and alarm master, you need to choose a compatible protocol. You might need something older like E2A, TBOS, TL1, or TRIP. You might need something newer like SNMP or DNP3. Make sure your RTU supports the necessary protocols.


Can I honestly expect to find an RTU that covers all my requirements?

If you know where to look, you can find the RTU you need. You may simply need to adjust your thinking just a bit.

First, look for a manufacturer who has done this before. What microwave transmission sites have deployed their gear already? Are the end-users happy with the results? Can you call them yourself to hear their thoughts, or do you just have to take the manufacturer's word for it?

Second, remember that some element of your specification may not be available 100% off-the-shelf. You can probably find a 90% match, but one part may be missing.

That's when you need a manufacturer who will adjust their design to fit your needs.

You also shouldn't need to order very many units; and purchasing more than 10 should not incur NRE fees.

What about Central Monitoring Consoles?

Good RTUs are important, and they can generally handle themselves if you have fewer than 12 RTUs in your fleet.

With a small number of facilities, you can program your RTUs to send you SMS or emails whenever there's an issue.

With more than 12 sites, you need a central alarm collector to help manage alarms throughout your network. Just like RTUs, however, there are good master stations and bad master stations. Here's what to look for:

What if I need Training to use my monitoring?

A monitoring system is a significant equipment investment, and it only has value if your team can set it up and use it properly. This is where many vendor offerings fail to offer hands on training and support.

What will really serve you best is a variety of training formats.

Your primary users will probably want classroom training (or at least videos that simulate a classroom environment). During installation and routine updates, a good tech support line will help you with your questions. Solid documentation (print and online) will help you when you just need a simple reference guide.

You'll know you're dealing with a full-service, high-quality vendor when you get all that for free. Even classroom training should be free if you're willing to travel to a training center. If you need training at your offices, that should also be available for a reasonable price.

Classroom training for RTUs usually takes only about a day. They're fairly simple when compared with master stations, so there isn't as much material to cover. Comprehensive master station training takes 3-4 days, because master stations have so many functions. You need to understand not only day-to-day monitoring, but also the initial configuration process.

Classroom training is a good idea for a few reasons. First, you get live attention from the instructor (you won't get that from a YouTube video). Second, you can ask questions in real-time. Also, most people don't consider that their classmates at training will be a big resource. It's rare to interact with colleagues from half-a-dozen other companies at once. They'll all have similar kinds of experience, so they can probably offer real-world insights about monitoring that your instructors (with all their product knowledge) cannot.

Avoid the trap of microwave-integrated monitoring systems

Many transport manufacturers provide some kind of monitoring function. In the case of microwave systems, you frequently get a few contact closures and a bit of overhead bandwidth to transmit alarm data. This can seem like a good idea (and it's certainly better than nothing at all), but consider the negative impacts of a monitoring system that's integrated with (and, therefore, totally reliant on) your microwave transmission equipment:

Protect Your Microwave Transmission Reliability with a Dedicated Remote Telemetry Unit Now

The KDA 864 RTU is one remote that can help you protect your important microwave communication equipment.

The KDA 864 provides you with 64 alarm points and 8 control points in a single 19-inch rack unit. It also supports 202 modems for use with microwave base bands 0-4, as well as FSK modems on 4-8 and 8-12 base bands. With support for DCP, E2A, TBOS, TL1, TRIP, or TBOS, the KDA 864 will protect your microwave communication to keep your network online. If you need more capacity, you can connect up to four KDA's to form a larger alarm unit.

Don't let a major outage destroy your service reliability. In today's business climate, that's something you simply can't afford. Deploy a KDA remote in your microwave network today, and start collecting the alarm data you need to provide the high-quality service your customers demand.

Dozens of NetGuardian models are available for remote monitoring. They all do more or less the same thing (monitoring and control automation), but have different capacities and different transports, form factors, etc.

Part 2: How to monitor your antenna towers

Microwave data is the information that makes up a microwave communication message. This data can be any type of message that is transmitted between microwave towers using microwave communications equipment.

Get a Custom Application Diagram of Your Perfect-Fit Monitoring System

There is no other network on the planet that is exactly like yours. For that reason, you need to build a monitoring system that's the right fit for you.

"Buying more than you need" and "buying less than you need" are real risks. You also have to think about training, tech support, and upgrade availability.

Send me a quick online message about what you're trying to accomplish. I'll work with you to build a custom PDF application diagram that's a perfect fit for your network.

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Your monitoring system shouldn't be, either.

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