What is a Network Radio?
Network Radios are a relatively new type of 2-way PTT (Push To Talk) Radio Communications Equipment that make use of existing electronic components, RF modules, touch screens and sub assemblies mass manufactured for the mobile telephone industry. These parts are used to create many styles of handheld, portable and 'in car' devices that feature built in PTT buttons and/or external plug in microphones with a PTT switch.
Most currently available Network Radios use the Android Operating System allowing easy installation and use of many Android Applications including 2-way simplex communications APPs such as Zello PTT that provides users with easy to operate Global simplex communications. Most network radios can also be used with Bluetooth headsets, speaker mics, headsets, media buttons, keyboards, mice and other peripherals.
There are growing numbers of unlicensed radio enthusiasts, licensed amateur radio operators and business users making good use of network radio equipment to communicate around the world.
Although You will hear some people stating that network radios are 'not real radio' or 'not using RF' they are indeed mistaken.
It is correct to state that Network Radios are 'not HAM radios' as they do not operate on frequencies allocated for licensed amateur operation and fall outside the scope of Amateur Radio licensing but they are real radio communications devices that do use RF.
Network radios are effectively classed as 'license exempt radio communications equipment' The end user does not require a license to operate these devices on mobile networks or WiFi connections as the bands of radio spectrum used for mobile network communications are licensed by the network infrastructure owners/network operators and WiFi connections use licence exempt 'ISM band' frequencies.
How do they work?
Network Radios (and mobile telephones) communicate by establishing data connections with radio transceiver equipment located at 'cell-tower' sites. The mobile devices are transmitting and receiving very low power radio frequency energy propagated through free space to connect to the RF equipment at the cell tower sites using a range of different modes and communications protocols such as, GSM/2G/3G/4G/LTE/CDMA/WCDMA and many others.
The global network of 'cell-towers' operating as RF gateways provide radio data communications for mobile devices on various chunks of the radio spectrum including blocks of frequencies around 700MHz 800MHz, 900MHz, 1.6GHz, 1.8GHz, 2.1GHz 2.6GHz and others. The devices connected to the cell tower gateways are then inter-connected through the 'back end infrastructure' of the cellular communications networks Worldwide.
The specific bands, uplink/downlink frequencies, modes and data transfer protocols used at any given time depends on the specifications of the device in use, mobile data provider/SIM type and cell tower network coverage at the current location.
The mobile phone user or network radio operator does not need to think about selecting or changing between the various bands, modes or protocols as the network radio RF module, supporting hardware and software in the device deals with all the band, frequency, receiver gain, RF output power and mode switching automatically as radio signal propagation conditions and signal strengths change.
Bluetooth and WiFi data links operate in the 2.4GHz ISM band. Most Network Radios default networking configuration will uses the WiFi data connection as its preferred primary network data communications mode automatically switching to the mobile data network when the WiFi connection quality/signal strength drops. These devices will reconnect automatically when the WiFi signal strength increases to a workable level. WiFi and Mobile networking can be selectively enabled or disabled by the operator when required.
How much data do they use?
The amount of data used by a network radio device will vary dependent on how much is is used.
It also very much depends on which applications You are using on the device.
There are many different applications available for network radios and mobile telephones that provide 2-way simplex communications functionality, some applications use more than others with the 'Zello PTT' application being one of the best due to using an advanced rate adaptive/variable bandwidth CODEC (coder/decoder) that compresses the relatively narrow audio bandwidth used for voice communications efficiently while providing very good quality reproduction of the voice.
A Sim card deal that provides 200mb of data per month should be more than enough for occasional users who have a single channel switched on at a time and have 'sending and receiving images' turned off.
1 GB per month should be more than enough for the majority of people using Zello every day with image and text message sending/receiving enabled.
With multiple busy channels in use for long periods of time You will require a larger data package.
I personally use multiple Network Radio devices every day, these are often connected to the networks and operational for several days at a time. Using the Zello PTT application on One channel at a time (other channels switched off when not in use) uses less than 500mb per month .
If You have multiple channels switched on all the time, especially if they are busy channels You will use larger amounts of data.
With 12 channels enabled all the time, most of which are very busy, (three of the channels often have well over 5,000 transmissions per day) I have been using between 1.5Gb and 2.5Gb per month.
(The 2.5Gb total for one month included sending and receiving images on multiple channels, occasional web browsing, watching a few short videos online, checking email, uploading photographs and short time-lapse videos + using location tracking, cell signal monitoring/mapping and GPS applications that access map data online)
You will find that applications such as web browsers, GPS tracking/mapping apps that download map data, and full duplex communications applications such as Skype will use much more data than simplex PTT voice communications applications like Zello.
Most network radios can also be used as a WiFi Hotspot allowing other devices to access the internet through the network radios 3G/4G mobile network data connection, this will require a larger data allowance or SIM data deal with Your chosen mobile network provider.
Video streaming applications tend to be the heaviest data users so if You intend to watch video or stream video out onto the internet with Your network radio device (or other devices tethered to the network radio) You will need a much larger data package deal.
Of course if You only use Your network radio on home/office/work WiFi connections or tethered to a mobile hotspot on Your phone, portable 4G wifi router or other mobile internet wifi hotspot device You will not need a mobile data SIM in the network radio unit at all.