When looking at mobile two-way radio coverage, many users jump to the conclusion that the higher the gain rating is on an antenna, the better the coverage. That is not necessarily the case. In this blog, we take a look at the conditions that may affect coverage and help you select the appropriate gain antenna for best results.
Antennas do not make power; they only propagate radio waves. Different antenna designs have different propagation patterns. Unity gain (equivalent to 0 dB gain) ¼ wave antennas propagate RF in an omnidirectional, or circular pattern. Since an antenna does not make power, increasing gain in one direction will decrease propagation in another. Typically, antennas with gain will lose the vertical propagation or “roundness” of the pattern and become flattened and elongated with the higher gain antenna you choose. As you can see in the illustration, using a gain antenna may cause poor performance in a hilly environment.
Mobile antenna choice has a lot to do with the physical terrain. On an open and flat highway a high gain antenna will be better…3 dB, 6 dB etc. If your desired coverage area is hilly then a ¼ wave omnidirectional antenna will be better.
The other type of gain is directional and is important for base stations. These are usually called “yagi” antennas. As an educational metaphor, let’s compare gain to a flashlight. When you turn the bezel of a flashlight you are not increasing the power, you are focusing the light and making the energy denser in that area. In RF, for every 3db of gain you double the power. In the world of antennas you do not double the output, you double the density of signal level in a given area. For the purpose of a fixed base station transmitting to a (stationary) repeater, a high gain Yagi may be used to focus the RF energy directly at the receiving antenna. If you are using a fixed base station and transmitting to a mobile fleet of vehicles, a more traditional omnidirectional propagation would be better suited.
In conclusion, as with many things, your antenna gain choice depends on several factors. Generally, in the Pacific Northwest we tend to recommend 3 dB antennas for mobile radio users in order to account for both distance and our hilly terrain. Your individual needs may not fit a one-size-fits-all approach. We are more than happy to discuss your specific application and make recommendations for your specific needs. Give us a call.
This year, Washington, Oregon and California tightened restrictions regarding the use of handheld devices behind the wheel. These changes were all modifications to the original “hands free” or “distracted driver” laws in these states; laws that required updating and modernization. The new laws in these states focus on the act of holding an electronic device as the violation, and no longer require active texting or talking to earn a citation.
In 2016, 40,200 Americans died in automobile-related accidents. This represents a 6 percent increase over 2015, and an aggregate increase of 14 percent since 2014. The National Safety Council (NSC) partially attributed this increase to a healthy economy, which means more people on the road for both work and pleasure. However, NSC’s research more heavily implicated distracted driving, caused by handheld devices such as smartphones, as the culprit. Given this data, reducing the use of handheld devices on the road is warranted.
But many businesses rely on in-transit communication to complete operations-critical tasks every day. These professionals still need instant communication, but they must also comply with the law by communicating in a way that is conducive to roadway safety.
First Things First: Know the New Laws
Below are the three states to have adopted new laws regarding the use of handheld devices in automobiles:
As of late July 2017, all motor vehicles operators in The Evergreen State, including professionals with a commercial drivers license (CDL), are prohibited from interacting with a phone or other device in such a way that requires them to hold it. Any use of the device must be minimal – for instance, a quick swipe or tap of the finger to reject an incoming call. The penalty for a first offense is a $136 fine. Subsequent violations will result in a $234 fine.
Oregon Oregon’s new distracted-driving law goes into effect Oct. 1, 2017. Any device interaction that requires holding it, typing into it, scrolling or even resting it between your legs will result in a fine. Drivers using their phones must have it mounted, and must be able to interact with it through single-touch capabilities. Failure to comply with the new law means a first-time fine of a few hundred dollars, or a required safety course at the expense of the guilty party. Two violations in 10 years will result in a fine of up to $2,000, and a third violation comes with a minimum fine of $2,000 and the possibility of jail time.
California The Golden State first introduced its new distracted-driving law in January 2017. At the time, “specialized mobile radio device” and “two way messaging device” were on the list of prohibited devices. This had the unintended consequence of leaving commercial drivers vulnerable under the law.
However, in July, the law was amended to exclude mobile and dash-mounted two-way radio. The law still strictly forbids the use of wireless devices while operating a vehicle. The only exception is that drivers are allowed to activate or deactivate certain features with one touch, and that device must be mounted through a dashboard or windshield console.
How Are Two-Way Radio Users Affected by the New Laws?
While laws have tightened on mobile electronic devices, states have allowed many exemptions when it comes to two-way radio users, especially for commerce and public safety. These include the following:
· Drivers with a CDL and school-bus operators using the radio within the scope of employment.
· Drivers in the logging or utilities industry and using the radio within the scope of employment.
· Using a radio in police, fire, EMS or towing within the scope of employment.
· Any permanently mounted device (i.e., dash- or vehicle-mounted mobile radio).
Although the use of mobile two-way radios are legal and easier and safer to operate than cellphones, it is advised to keep conversations to a minimum when operating a vehicle.
Recap: What is allowed?
Keep your phone on a mount and use an approved hands-free device.
Receiving calls on a Bluetooth headset in this instance is OK.
When making an outgoing call, you must use voice activation.
Beyond a single touch or swipe, avoid touching your phone at all.
Vehicle-mounted (mobile) two-way radio use is legal in every instance.
Portable two-way radios are legal in several industries when used within the scope of employment, or if the driver has a Commercial Driver’s License (CDL).
Businesses must facilitate one of the above to avoid putting their employees in a dangerous and/or illegal situation on the road. A great option is to utilize a wide area radio system like TRBOWEST.
For more information about how to make your mobile communications compliant with state laws, click here to contact Day Wireless Systems. We’re wireless industry veterans with offices across the West who know the law and the lay of the land, and we’re here to help.
The Federal Motor Carrier Safety Administration banned talking and texting without a hands free device on January 2, 2012. The law excludes CB and two-way radios due to the simple, one-button push operation of a radio where drivers do not have to take their eyes off the road.
Recently, we had the opportunity to test this theory at a customer’s site. We set up a small test track to see if radios are really safer to use while driving in comparison to talking or texting on a cell phone.
The track was comprised of three main sections:
Curvy road track
Driver to make and receive calls during this section
Accelerate and stop – 1/4 mile acceleration to 30 mph and stop
Driver to place a call when traveling at 30 mph, and stop at the stop sign
Left or Right swerve around a cone based on 100 foot warning
While on a call, driver to follow passenger’s instructions to swerve left or right
DOT researchers have classified distracted driving into four categories:
Visual (taking one’s eyes off the road)
Manual (taking one’s hands off the wheel)
Cognitive (thinking about something other than driving)
Auditory (listening to the radio or someone talking)
The DOT favors two-way radio over cell phones primarily due to the visual and manual aspects of distracted driving.
“The odds of being involved in a safety-critical event are three times greater when the driver is reaching for an object than when the driver is not reaching for an object. The odds of being involved in a safety-critical event are six times greater while the driver is dialing a cell phone than when the driver is not dialing a cell phone. These increases in risk are primarily attributable to the driver’s eyes being off the forward roadway.”
Test #1 – Driving While Talking on a Cell Phone
Brandy (the driver) was able to navigate the curvy road track fairly well. However, any question that required a cognitive task forced him to focus on one thing or the other (the road or the call). He couldn’t do it. He focused on the road (the smart thing to do) and the conversation suffered.
“So I wasn’t paying attention…I was kind of more like paying attention to the road…”
Devin Edwards (Boss):
“I could tell you weren’t paying attention to me…I mean not really…You were only really halfway in the conversation.”
“Because I was thinking!”
The ¼ mile acceleration and stop proved to be difficult. At 30 mph, looking down at a phone for 1 second equals travelling 50 feet. There was about 150 feet that was allowed for deceleration. The driver blew through the stop sign on 3 out of 5 laps.
The driver failed to swerve in the appropriate direction on 2 out of 5 laps on the cone test.
Test #2 – Driving While Texting
Driving while texting proved to be extremely difficult and unsafe. The driver failed all three tests and it was obvious how difficult it was to text and drive at the same time.
“You find yourself looking at your phone more than looking through your windshield”
Me as a passenger:
“That’s not good…”
Test #3 – Driving While Using TRBOWEST (Motorola MOTOTRBO Digital Two-Way Radio System)
Brandy passed the curvy track portion fairly easily. You will notice on the video that he never takes his eyes off of the road. It was also noticeable in person that it was less stressful to converse over the radio than on a cell phone. I don’t have any science behind it, just an observation.
Brandy missed the stop sign in 1 out of 5 laps. This highlights some of the distraction that any cognitive function adds to the equation.
Brandy swerved in the wrong direction in 1 out of 5 laps. Again, this test stresses the cognitive overload of driving, talking to his boss, and listening to a passenger.
To answer the question, our tests strongly suggest that using a two-way radio while driving is safer than using a cell phone. You should never text while driving. However, even a two-way radio can cause distracted driving.
Best practices for using two-way radio while driving:
Keep conversations brief and business related
Keep the speaker mic within an easy arm’s length from the driver. If you don’t have to unclip the mic, even better.
Keep the radio volume loud and constant. Don’t turn up and turn down your volume throughout the day.
Thank you to Speeds Towing who was gracious enough to provide the manpower, time, and equipment to facilitate the test!