PTT over IP Communications – Part 1

What is PTT over IP?

Push-to-talk (PTT) logic has been around ever-since the emergence of early radios and phone “intercoms”, over a century ago. But PTT over IP solutions are still in their “infancy” today. Many organizations and projects that could greatly benefit from applying a PTT logic in their communications do not even know the solutions exist or they do not fully understand how they work or that PTT technology can easily be integrated with legacy radio and VoIP technologies to create highly scalable, affordable and efficient PTT communications system.

There is no universally accepted terminology for describing systems and products that deliver PTT experience in the IP networks. Product flavors, designs and purposes will greatly vary. You will come across terms such as PTT over Cellular (PoC), Radio over IP (RoIP), PTT over IP or wireless, IP intercoms, etc. We shall try to stay with “PTT over IP” throughout the text.

Modern PTT communication technologies, coming from a variety of sources, can deliver innovative IP based VoIP communication solutions with PTT logic to the end users. 

Such products are built around PTT (Push-to-Talk) logic, micro-computers and micro-controllers, highly efficient audio codecs (Opus) and modern VoIP communication protocols. They are applicable in projects and organizations of any size.

Using PTT communication devices brings numerous advantages, starting with lowering costs and making communication more efficient. At the same time, conventional legacy communication devices, like land mobile radios and modern “smart” communication devices can seamlessly inter-operate in the same communication network with other IP devices, thus creating a “hybrid” communication system. 

PTT over IP technology can help organizations lower their overall communication costs significantly and improve communication freedom by facilitating easy interconnection methods between diverse, otherwise incompatible communication means (radio networks, phones or third party applications), making the communication more universal. Such system can be made truly “global”, overcoming the range limitations of radios.

There aren’t many companies that can deliver a “hybrid” communications solution with PTT, to the end users at an affordable price, without creating a price shock or “breaking the bank”.

Let’s take a look at what PTT over IP communication system is all about and why your organization or project may be able to benefit from such a system?

In this document, we shall try to explore the key benefits of PTT over IP technology for small and medium size projects and give you an overview of unique possibilities of this communication concept.

What is Group Communication and why use it?

Three icons representing the various modes of communication that take place in a business environment. The first mode shows one individual at the top of a chain, which feeds down into two individuals, and from each of those two individuals comes three individuals. The second mode is one central person flowing to four individual in a circle around the center. The third mode of communication shows a group of people with lines between each and every one.

Group communication matrix

Group communication

Simply, this is a mode of interpersonal communications, where more than 2 people are involved in the exchange of information.


A group can be defined, as a number of people with some common goal, who interact with each other to accomplish their objectives. Group members recognize each other’s roles and see themselves as a part of functional team. They are assigned functions. A group needs to have a minimum of three members, otherwise the two persons, just working together would simply be referred to as a “pair” or “dyad”. In a project or organization, there could be many different groups, created many different reasons and they can change all the time.

“Group communication” method is often a primary mode of communication in most modern organizations, between employers and employees and among the employees within their functional teams.

Small groups can have 3 to 20 or more members. And larger group can consist of 100 , 200… or even more members.

A group…

Group communication can only be effective, when there is a specific purpose for the communication, when proper means for timely communication are available and the content of communication is useful to all of the team members for accomplishing their goals.

One person or functional level within a group will usually have a role of a coordinator, manager, moderator… a dispatcher. This level drives and directs group communication effort and group activities from a central point, like the main office or “operations center” for the entire group. The choice of the means of communication can depend on factors like the target audience, the means and availability of the communication methods and the cost implications for making the communication effort.

Enough with theory?

PTT – Why is it an ideal logic for group communication?

Use PTT technology or make a phone call?

Communicating with PTT logic within a small or medium size group can be much more efficient from making phone calls all day long. Communication professionals and people using the radios fore work know this. They don’t need to be convinced. Combine the “radio-like” PTT logic with phone GSM/ 3G/ 4G/ LTE and soon the 5G networks increasing the connectivity everywhere globally and you can harvest all the benefits of both technologies while mitigating the weaknesses of each. It is a “winning strategy” for efficient group communication.

Let’s look at a following practical example…

Phone users example

A team of 15 members is making 30 mobile phone calls each, to the main office and each other, during a regular working day. Some team members talk more, some less, but we can assume they make 30 shorter or longer phone calls every day, in average, to coordinate every-day activities within their small team or with the main office.

The time to establish a call is estimated to take 20-30 seconds per call. This means unlocking a phone, finding a number in the phone-book, dialing the number, the ringing time, answering call by the other party, hanging up, redialing sometimes, etc.

How many team members? How many calls made / day? Call establishment time (seconds) Lost call establishment time on the phone per person / day (minutes) Lost call establishment time on the phone for the group / day (hours) Lost call establishment time on the phone for the group / month (22 days) (hours)
15 30 20-30 10-15 2.5-3.75 55-82.5

Table 1. Group call establishment time loss when making phone calls

Estimate shows, that each member of the team can easily spend 10-15 minutes on the phone every day, just dialing and waiting for the calls to be answered.

The group of 15 members, basing their communications on mobile phone calls to coordinate their actions, is wasting anywhere between 2.5 – 3.75 hours every day, in unproductive communication due to the needed call establishment times. This amounts to 55 – 82.5 hours a month of inefficient communication. The bigger the team, the more time is wasted in call establishment times. Did you think about this? Do you have a choice?

Let’s compare mobile phone calls to more efficient PTT logic?

How many team members? How many calls / day? Call establishment time (seconds) Lost call establishment time on the device per person / day (minutes) Lost call establishment time on the device for the group / day (hours) Lost call establishment time on the device for the group / month (22 days) (hours)
15 30 instant 0 0 0

Table 2. PTT over IP technology. Practically no time is wasted for call establishment.

Why PTT over IP communication is more efficient from phone calls for small and medium size groups?

How else does the PTT over IP communication model compare to phone calls? We learned that establishing calls with PTT logic, at a press of a button is almost instantaneous. Practically, no time is wasted. Just press a button and talk to the group. All that time wasted in establishing traditional phone calls can now be used more productively by each of the team members. At the same time, important group relevant information, does not have to be relayed anymore by either of the team members making multiple phone calls to other team members, in order to share the information.

Sending emails and waiting for response from other team members to coordinate activities can be greatly reduced too. Group relevant information can be shared in real time, between all of the team members.

PTT over IP Communications – Part 2