Most of us probably have a wireless router in our house right now. 802.11a/b/g were the old standards, 802.11n is the current standard and 802.11ac is coming in the near future. You don’t know how it works, but you plugged in your wireless router when you picked it up from Best Buy (or your cable/internet provider), fumbled your way through it and low and behold-- you’re a wireless networking specialist! Congratulations. You’re not sure exactly what's happening on the back end, but your laptop at home works as well as your smartphone connecting to your WLAN to surf the web.
WARNING: This article assumes you have an intermediate understanding of RF and two way radios.
Every so often you may experience a problem with your mobile radio, regardless of its manufacturer. I've heard one of our technicians once say “a radio is a radio; it transmits and it receives. I don’t care if it is Motorola, Johnson, Kenwood or Vertex.” It doesn't matter what type of radio you have because they all need the same basic components to work properly. Because of this, we can point out a few problems that typically occur among all mobile radios.
In order to address a mobile radio problem you first need to know which part of the radio isn't working properly. Before we get to troubleshooting, let me define the pieces that make up a mobile two way radio:
Over the last thirty years, I have actually counted over 200 radio dispatch consoles that Chicago Communications has installed. A dispatch console is actually an interface for a dispatcher to talk to various radio systems. Similar to a 9-1-1 telephone system, the radio dispatch console acts as an audio switch to connect various people to various radios or telephones.
I have to say, in my 32 years of being in radio, the MOTOTRBO product line is one of the best ideas I have seen come out from Motorola Solutions in a long time. Back in 2007 I remember seeing it for the first time. When I heard 2-for-1 channel usage, it immediately made me think of reducing our customers capital outlay for radio systems. In addition with many users still using Micor vintage equipment, the time was right for this product.
MOTOTRBO’s ability to cross both the analog and digital platforms really gave the customer a choice. It allowed the end user to migrate from a legacy platform of equipment operating on analog to a digital platform that allowed 2 simultaneous voice conversations over one radio frequency. DOUBLE CAPACITY with one system!! Purchasing an upgraded infrastructure backbone can allow a customer to operate analog until the customer gets enough mobile and portable radios; and with a simple programming to digital, the customer effectively has two repeaters in one system.
Motorola Solutions went one step further by allowing Application Developers to write software code to the radios to allow it to act as a modem or input/output device. By creating this digital platform, these binary ones and zeros carry more information than just voice.
Storm season: A radio shops favorite time of year. (Just Kidding!) Actually it has gotten progressively better. Years ago before Motorola’s Site Installation and Grounding Practices (R56 Standard), it was common place to have most of your yearly calls in the spring and summer due to storms. After countless builds using the R56 Grounding methods, we actually have minimized and eliminated costly repairs or insurance claims.
All radio systems involve communicating at a minimum between two individuals. For commercial systems this means connecting groups of people within a building. Today commercial systems, whether industrial manufacturing, hospitality or transportation, are requiring a wider area of coverage to communicate between individuals. So the question becomes, "How do I take my simple system and create something that communicates over a larger geographic area?"
One of the answers is Digital Mobile Radio or DMR. Todays' radio systems operate in a similar fashion to the cellular systems with digital. By converting these analog radio signals to digital we can take that data, wrap it with the proper coding and basically send it anywhere in the world. The details are a bit more complicated than that, but the concept is sound.
With the current mandate by the FCC to narrowband radio frequencies below 512MHz, we have observed coverage issues. Many engineering documents speak of loss of coverage anywhere from 3db to 6db in coverage. We have noticed a 3db loss in systems, especially if those systems have spotty coverage to begin with. We always use the rule if you have a full quieting RF signal now, you most likely won’t notice the change. If you have poor coverage in some locations, you will notice a difference. With that said, there are a few options available to choose from.
Employers are realizing that the concept of purchasing cell phones for employees is quite an expensive option. Although it provides connectivity to employees over a wide geographic area, it also has lead to personal calls, texting and additional charges that have to be monitored continually. With potential legislation in congress to eliminate cell phone use in cars and especially commercial vehicles, you need options to communicate with your people in the field.
I can’t tell you how many times we run across systems improperly designed based on their licensing requirements. Each FCC licensee is required to meet both height and power requirements for all of their fixed base station equipment that is indicated on their license.
Many times people take the approach that to reach their people in the field they need to increase the gain of their antenna’s and the power on their base stations. What they don’t realize is that they may become an interferer with an adjacent co-channel user and are therefore subjected to a fine by the FCC for exceeding their licensed effective radiated power. We had one instance where the combined antenna gain and power from their equipment was enough to reach Madison Wisconsin from the Western Suburbs of Chicago.