Using a cell phone as a two way radio: good idea or not?
The capability of the smartphone is always growing. One of the recent developments has been the ability for smartphones to act as and interface with two-way radios. Multiple manufacturers have come out with this as a complementary solution to two-way radio systems. If you are the current holder of a corporate cell phone and want to interface with staff that carry radios, this may seem extremely attractive. It is, but the drawbacks should be considered.
1. Latency and Battery Drain – Cell Phones are not designed to work like a two way radio.
Two way radios are designed to provide immediate communication. The interface of a cell phone to a radio system is a data application. Utilizing either the cellular network or WiFi, the cell phone accesses a gateway tethered to a radio that interfaces the other radio users.
When you hit push to talk (PTT) on the radio application, you are transmitting data to the gateway that sends the information to a radio that works with other radios in your environment. As long as the application is active, the phone will hear radio traffic from that radio through the network.
Phones inherently treat data different than the phone features. How often do you check email? Every second? No way! Your battery would be dead by 10:30 AM. The same with thing applies with data applications. Applications are designed to reference the existing network on a less frequent basis. The more often your cell phone is checking the network, the more battery drainage there is. So it is better to have the phone check the network less frequently than it checks for potential calls. The result is that radio traffic from the gateway will not necessarily reach your phone in real time if the phone is in standby mode. If a call comes over the radio indicating that “there is a fire!” you would want that information sooner than later. If you got that call 30 seconds later, or in some cases 60 seconds later, would that be acceptable? Probably not.
Conversely, if the application is active, it is attempting to access the network on a semi-regular basis. The result; battery drain. Batteries for cell phones were never designed to run a radio application and meet the demands of the immediacy of PTT activity.
2. Durability – Radios are built for commercial use, phones are not.
When you purchase a two-way radio, you are purchasing a device designed and built to be a 10 year tool. Regardless of the Manufacturer, most are built to Military Specs that far exceed any cell phone on the open market. If you use your cell phone as your gateway to your two way radio community, you are put yourself at risk for being out of communications if your cell phone dies. Be it battery life or a fatal drop, you are using a consumer product for commercial use.
3. Dependency on a Third Party – Your own your radio system and control it, cellular service and WiFi are dependent on others who may not be there when you need it.
When radio transmissions reach the gateway, they are sent to the network that you are accessing. In the case of WiFi, you getting the radio transmission along with all of the other tasks that the network is processing. If the network is overtaxed, latency will be affected. If you are out of range, the call will not be heard. The same situation occurs with cellular, if you are out of range, you will not hear radio transmissions More importantly with cellular, the problem can be potentially disastrous. Should an catastrophic event occur,cellular networks can be rendered useless. Meanwhile, your radio system still works, you just can’t access it because you have a cellphone.
4. Price – Costs to interface existing cell devices often exceed provisioning additional radios.
Since you already may have cell phones in place, it would seem that the costs would be minimal to add the application to interface radios. In reality, replacing radios with applications may not save as much money as one might think. The interface to radios has an equipment cost and the application has a cost per unit for the phone. Basic phone interfaces will exceed the cost for a few additional radios.
Obviously, other considerations need to be examined. Coverage, for example, may be better with a cellular device. If you own a company and live far outside the coverage of the radio system, the application will be of tremendous advantage. You can transmit and receive to radio users via a cell phone where a radio would never work. Want to dispatch (or monitor) a fleet of vehicles from Florida? No problem! Want to monitor activity at work after you get home or get an after-hours quick message to a 3rd shift employee on radio? Easy. These applications can do that and do it well.
There are definitely situations where a radio application makes sense. They work well for what they are trying to accomplish, You can contact an employee who has a radio right from your cell phone. In the case of mission critical communications, too many other dependencies currently exist to make it a viable solution. You can use it as a tool, just don’t rely on it as your only tool.