The short answer is that they all refer to solutions that provide workgroup communications between different types of devices over existing connections like 3G, LTE and Wi-Fi. The long answer is not only more exhaustive but also interesting for several organisations.
Two-way radio can by some people be viewed as outdated. If you instead look at the feature that the radio represents, namely instant group calls, that point-of-view is challenged. PTT-over-broadband, PoC, etcetera are solutions that are increasing in popularity and since they basically virtualise the physical radio, you could argue that “two-way radio” will be as current tomorrow as last century.
To simplify we will only use Push-to-talk (PTT) over broadband below as this term best describes the technology.
Push-To-Talk-over-broadband
By connecting smartphones, tablets, computers or even two-way radios through a server you get the opportunity to interact between them, independent of geographical location. Such a server can be available either as a service in the cloud or installed locally at your organisation depending on selected solution.
Talk group communications
By dividing users into talk groups one, ten, hundreds or thousands of recipients can be addressed simultaneously without dialling time. A talk group consists of two or more users that have a mutual need of interacting, where individual users can be included in multiple talk groups. Both users and talk groups can be prioritised within some systems to ensure that important information is relayed without delay.
Connection
PTT over broadband uses already available networks to connect users. Smartphones can use public service providers, tablets may use Wi-Fi, computers connect with network cables or two-way radios via dedicated infrastructure. Certain devices can also utilize multiple connections in parallel to ensure accessibility and some solution even have specialised end-user devices. All in all the reach of PTT over broadband is absolute or at least global.
Flexibility
Since these solutions usually support numerous different platforms the users can operate the device that is most suitable for their role, situation or environment.
Choosing system
There are many suppliers of Push-to-talk over broadband. They vary a lot in size, are from different countries and have different approaches. When choosing supplier and solution some factors should be considered. Especially if it concerns a cloud service.
Security
How are the communications secured? Where are the servers placed?
Availability
How is the overall availability? Which operating systems are supported? Which connections can be used and/or are required? How is the solution administrated?
Supplier
What is their background? How does there current situation look? Do they offer a privacy policy? How is the agreement?
Miscellaneous
Does it support emergency calls? How does location tracking work? What does the dispatch look like? Can the system be integrated with anything else?
Final note
Even if PTT over broadband likely is the group communication solution of tomorrow the conventional two-way radio still holds a clear place alongside our smartphones.