A modern telephone can be used as a walkie-talkie only if it is equipped with special application. Also an indispensable condition is access to the Internet.

Modern cell phones can be used far beyond their intended purpose – making calls. Due to pre-installed on devices operating system It became possible to expand the list of gadget capabilities almost indefinitely.

This way you can even turn a cell phone into a full-fledged walkie-talkie. How to turn a phone into a walkie-talkie? In order for the walkie-talkie on your phone to work, you will need an Internet connection. What’s good is that a normal radio is quite enough for the radio to work. mobile internet, operating on 2G technology. First, you need to download the radio to your phone. One of the most common walkie-talkie applications for modern cell phones is Zello. You can download and install Zello directly through Google Play Market. Next, when the program is installed on your phone, you can begin registration. It takes just a few minutes. You need to come up with a nickname, which will also be your login to enter the program, and a password. If you wish, you can specify a telephone number, address Email and other information about yourself. It will be recorded in the application profile. Communicate via walkie talkie Zello possible with everyone who also has mobile devices or installed on your computer this application. Moreover, you can communicate with your interlocutors both through common channels, directly or in closed-type channels. Why and who can use a walkie-talkie on a cell phone? A striking example of the use of a walkie-talkie on a cell phone is communication via password protected a channel between members of the same team in a search game. Zello is also suitable for maintaining communication within a tourist group in case the group has to split up on a trip. 2G Internet works in most suburban areas, which allows you to easily connect to the radio and transmit messages. To transmit a message via radio, you need to hold down round button on the display and talk. As soon as the button is released, the message will begin to be broadcast. It is worth considering that, despite the convenience and ease of use of the walkie-talkie application, it cannot act as the main communication channel. The fact is that the work of the walkie-talkie application, and even more so its work coupled with connection to mobile network data transfer quickly drains the phone's battery. Therefore, if communication via walkie-talkie is required constantly over long periods of time, and the ability to constantly recharge the battery is not provided, it will be easier to use a regular walkie-talkie tuned to the common frequency of all participants in the communication.

Nowadays, a phone with a hybrid walkie-talkie is a rarity. Somewhat paradoxical, yes, since progress has already gone quite far. We use smartphones with touch screens, the diagonal of which has already reached six inches, we surf the Internet at enormous speeds, we play games on our phones that previously could only be played on desktop computers, but we just can’t promote hybrid devices to the market that would work both as a telephone and as a walkie-talkie.

Why?

A telephone with a walkie-talkie is not that expensive a device. Rather, the issue here lies in demand. Although we can say that in previous years a principle called Push to Talk was used. It is designed to operate in walkie-talkie mode, but only when there is a signal cellular communications. But a telephone with a walkie-talkie that would actually work in civil band, for some reason became a headache. The scope of application of such devices is large, if you think about it. The same fishing and hiking in the forest, sporting events, walks in the parks.

Advantages and disadvantages

A telephone with a walkie-talkie is capable of providing communication between subscribers even where there is no ordinary coverage. The stated distance is two kilometers. But do not forget that this is only true for open areas. In urban environments with a high density of buildings and other elements, the distance will be reduced. Still, a phone with a walkie-talkie will have some advantages over a regular device. Today we will deal with the “unkillable phones” category, namely, we will talk about the Senseit P8 model. This is a “work of art” by the Russian company of the same name.

Specifications

It is clear that “unkillable phones” do not differ in special indicators. They were not created to show off the transcendental technical characteristics. But still, what does this walkie-talkie phone have? It has a screen with a diagonal of 2.4 inches. In this case, the display is 320 by 240 pixels. There is a camera. Its resolution is 2 megapixels. You can install two SIM cards; they must be of a regular format. The lithium-ion battery has a capacity of 2,000 milliamp-hours. The battery lasts 12 hours in talk mode. The weight of the device is 180 grams.

Exterior

Protection

As mentioned at the beginning of the article, the mass of the device is 180 grams. For many models, such parameters are standard. The device is protected only by the IP56 standard. The device must not be drowned in water. It's another matter if he just fell into the water. However, after this it must be pulled out immediately. It seems that there should be no problems with further work, but for some reason the manufacturer refrained from commenting. This doesn't inspire confidence, to be honest.

Arrangement of elements

At the top end you can find the SOS button. It can also be programmed to be sent to a particular number. The button is stiff and you can't just press it. This is already good, since accidental pressure is completely eliminated. On the left side there is a connector for connecting a MiniUSB cable. There is also a charging port and, of course, a jack for a 3.5 mm wired headset. On the opposite side there are buttons for changing the volume, as well as a radio button.

Back part

This mobile phone with the walkie-talkie is really replete with screws. Just look at the back cover. It is attached to the surface using two corresponding elements. By the way, the rotary screws can be opened using an ordinary coin. Adheres to the surface back cover quite tight. Removing it will not be as easy as it might seem. Even after the screws are unscrewed, it should be lifted by the recess. Here you will need some kind of object, since it seems almost impossible to do this using just your finger.

Design

Overall, it certainly gives me mixed feelings. On the one hand, the manufacturer sacrificed the protection of the device, but added another battery. This is very important when using a walkie-talkie. The walkie-talkie itself consumes a considerable amount of charge. But on the other hand, thanks to such a design, it will not be possible to open the case quickly. And this is already a minus, since quickly changing the battery is not an option. A clear advantage is the absence of a protective mesh near the speaker, since its volume automatically increases. Thus, the phone can be heard under any, even inappropriate conditions. Moreover, this rule applies both to voice calls and directly to telephone conversations.

Conclusion and reviews

What buyers say of this device? First of all, among the advantages of the device, they highlight a very loud ringer. It is simply impossible not to distinguish him. Even if there is real urban chaos all around. The vibration alert is also good. In general, the decision to abandon the protective grid when planning the speaker was, as they say, only beneficial. Everything is fine with the connection, no complaints this parameter No. Among the disadvantages was the impossibility quick replacement battery (shoutout to the unsuccessful design and its developers), a weak battery and a camera that is not worth taking pictures with. Although, did we really expect anything different from a walkie-talkie phone? The device does not need anything else; we have presented it completely. The cost of the device is currently 7,500 rubles.

The progress in the development of technologies for mobile networks does not stand still, and with each new standard and technology for mobile networks, new opportunities for using the network open up for end subscribers. In our conversation today about mobile technologies We will talk about additional functionality, which is based on packet transmission of voice data - Push-To-Talk (PTT, P2T, Press-To-Transmit).

Intro

PTT technology or, to be precise, PoC (PTT over Cellular) is not a new service in mobile networks, but the peculiarity of providing such technology requires the introduction of new elements into the architecture GSM networks operators who "borrow" from the IMS architecture and thereby ultimately promote the implementation of more effective methods transfer of information in the operator’s network, and also to some extent simplify the evolution of the network to newer standards.

Let's figure out what this technology is in general terms.

So... Technology RoS(a similar Walkie-Talkie technology) allows us to use the phone as a walkie-talkie in the usual sense and allows us to transmit a voice message to an active group/subscriber. Just like a regular walkie-talkie, you need to press and hold a special key called the “push-to-talk” button during a conversation. In this case, the main difference from a regular conversation with circuit switching will be that your short voice message will be transmitted over packet data channels, i.e. GPRS/EDGE will naturally be much cheaper for the end user. Each piece of voice data is delivered to the recipient via a dedicated network mobile operator PTT server. The AMR codec (5.15 Kb/s) is used for speech encoding. A user can use voice data transmission to another user (unicast) or group of users (multicast).

In the case of PTT, the optimal response time is determined at 1-1.5 seconds, and the transmission time voice message(delay) is calculated at up to 2 seconds. It is impossible to interfere with the transmission of voice information, as in the “classical” radio transmission using walkie-talkies. In the case of a busy transmission, the interlocutors will be served one by one, in the order in which they press and hold the “Talk” button (PTT key).

The conversation is carried out in classic half-duplex mode (simultaneous one-way communication), i.e. the interlocutor hears you only when you hold down the “Talk” key, in turn, you can hear other members of your group only when you release the “Talk” button.

The main advantage of this technology over “classical” ones is portable radios is, of course, the distance at which you are available to other participants, because in this case, the only limitation is the coverage area of ​​the mobile operator.

In this case, the conversation mode is very similar to the implementation scheme voice services in IP telephony, because The same protocols are used - SIP (Session Initiation Protocol) and RTP (Real-time Transport Protocol):

• SIP is used as a signaling protocol
• RTP for direct voice data transmission

The general scheme for implementing the PTT service can be represented as a figure:

As you can see, establishing a session with another subscriber, i.e. transmission of a voice message over the air is very similar to the transmission of voice information in IP telephony, because SIP protocol is used.

Summary

It should be noted that on the market of mobile devices there is quite a wide choice of them that support the PoC service; the bulk of the devices are represented by Nokia and Motorola, which quite widely developed and promoted the PoC standard.

The PoC service is in demand for taxi services, tourist organizations, groups of subscribers constantly exchanging short voice data, and is a kind of alternative to conference calls.

The very introduction of the service shows the gradual transition of operators to the IMS concept, which in itself is a good indicator. Further development of the PoC service involves deeper integration with multimedia services, for example, a subscriber will be able to find another subscriber using the so-called. LBS (Location-Based Services) will then be able to send him a short message using the PoC service, possibly send him a short message text message(MIM) or multimedia message (MMS).

Another direction of development of the PoC service is the provision of the so-called. Push-To-Video services that allow you to send/start a video message to another subscriber/group of subscribers using a mobile terminal.

A little helper:

AAA Server- Authentication, Authorization & Accounting Server
BTS- Base Transceiver Station
ISC- InterSystem Communication
MIM- Mobile Instant Messaging
MMS- Multimedia Messaging Service
PS Core- Packet Switched Core
RADIUS- Remote Authentication Dial In User Service
RTCP- RTP Control Protocol
RTP- Real-time Transport Protocol
UE-User Equipment

Modern cell phones can be used far beyond their intended purpose – making calls. Due to the operating system preinstalled on the devices, it became possible to expand the list of gadget capabilities almost indefinitely. This way you can even turn your cell phone into a full-fledged walkie-talkie.

How to turn your phone into a walkie-talkie?

In order for the radio on your phone to work, you will need an Internet connection. The good news is that for the radio to work, a regular mobile Internet using 2G technology is quite sufficient.

First, you need to download the radio to your phone. One of the most common walkie-talkie applications for modern cell phones is Zello. You can download and install Zello directly via Google Play Market.

Next, when the program is installed on your phone, you can begin registration. It takes just a few minutes. You need to come up with a nickname, which will also be your login to enter the program, and a password. If you wish, you can specify your phone number, email address and other information about yourself. It will be recorded in the application profile.

You can communicate via Zello walkie-talkie with everyone who also has this application installed on their mobile devices or computer. Moreover, you can communicate with interlocutors both through general channels, and directly or in closed channels.

Why and who might need a walkie-talkie on a cell phone?

A striking example of the use of a walkie-talkie on a cell phone is communication through a password-protected channel between members of the same team in a search game. Zello is also suitable for maintaining communication within a tourist group in case the group has to split up on a trip. 2G Internet works in most suburban areas, which allows you to easily connect to the radio and transmit messages. To send a message via walkie-talkie, you need to hold down the round button on the display and speak. As soon as the button is released, the message will begin to be broadcast.

It is worth considering that, despite the convenience and ease of use of the walkie-talkie application, it cannot act as the main communication channel. The fact is that the work of the walkie-talkie application, and even more so its work coupled with a connection to a mobile data network, quickly drains the phone’s battery. Therefore, if communication via walkie-talkie is required constantly over long periods of time, and the ability to constantly recharge the battery is not provided, it will be easier to use a regular walkie-talkie tuned to the common frequency of all participants in the communication.