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Introducing the SATELLINE 4Pro

SATEL’s latest high power, heavy-duty radio modem, the SATELLINE-4Pro includes the reliable features you’ve come to trust in a SATEL 35W transceiver, while also offering faster data speed (14400 bps at 12.5 kHz) at 8FSK and 16FSK modulations. The radio also allows for adjustable output power, to as low as 2W. This is a most appreciated feature for applications such as Machine Control, allowing operators to save crucial battery life on-site. IP67 classified housing ensures protection against moisture and dust. 406.180—470 MHz tuning range and selectable bandwidth of 12.5 or 25 kHz. Available in Survey Mode only. The LCD and keypad can be used to monitor the current operating status, as well as to change the operating channel and power level of the radio. The SATELLINE-4Pro is compatible with all SATELLINE-EASy products (8FSK and 16FSK modes are only compatible with 4Pro and TR4 based models). Wondering which radio better fits your needs, the classic EASy Pro 35W or the SATELLINE-4Pro? See comparison below:

Features SATELLINE-EASy Pro SATELLINE-4Pro
Frequency Range 403-473 MHz 406.180-470 MHz
Bandwidth 12.5, 20 or 25 kHz 12.5 or 25 kHz
Output Power (selectable) 10W, 20W, 25W, 35W 2W, 10W, 20W, 25W, 35W
Modulation 4FSK, GMSK 4FSK, 8FSK, 16FSK, GMSK
Firmware Standard or Survey Survey Mode Only
Data Speed of Radio       Interface at 12.5 kHz 9600 bps 14400 bps (at 8FSK or 16FSK)
AES-128 encryption? Yes Yes
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Tech Note: Using Configuration Manager

SATEL Configuration Manager is an essential tool for loading settings to your Satel modems. One feature that can make that fast and easy is the ability to load settings from a pre-existing file. That way, if you need to load the same settings and/or a channel list on multiple units, you don’t need to individually key in the settings for each one. The settings of the first unit you set up can be saved to your PC by clicking on “Save Configuration to File”. On the next radio you set up, click “Load Configuration from File” and “Open” the cfg file that was saved. When completed, all loaded settings are red and an info tablet opens stating “Configuration file loaded successfully!”. The settings are then uploaded to the radio by clicking “Write Settings” on the top tab of Configuration Manager. Settings files should only be used across matching models, so settings for the EASy 1W should not be loaded to the EASy Pro 35W, for example.

When in Survey Mode (aka SURV firmware), there is a helpful feature specifically for channel lists. You can save the channel list separately and in a format that can be used across Satel radio models, as long as the “Tx Power” setting is set to “0”, indicating max power can be used. Select the “Program Preferences” tab, enter password for maintenance mode, then in “Modem Settings” select “Open Channel Selector”. Build your channel list by selecting “Add” and remember to put “0” in “Tx Power” (unless you have restrictions that prohibit you from doing so). Select “Save” to save the channel list to your computer to load to other radios. Select “Load” to load to your current radio, then click “Write Settings”.

Note that the new Satelline-4Pro requires Configuration Manager version 1.6.1 which can be found on our website, under Service > Software, or by clicking here.

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Tech Discussion: Over-the-Air Speed and Modulation

Few radio parameters can be as confusing as modulation and over-the-air speed, for users at all experience levels. Here we hope to briefly shine some light on the subject:

Over-the-Air Speed

Although serial port speed and over-the-air speed have some relation to each other, they are totally separate settings.

While the radio’s serial port speed and the GPS receiver’s port speed must match exactly (for example GPS = 9600 bps & radio = 9600bps) to allow the normal transfer of data over the connecting cable, the speed over-the-air cannot be set by simply changing the port speed. Over the air speed is a fixed value which depends on both bandwidth and modulation.

In the US, the most common bandwidth today is 12.5Khz. So if your radio uses any of the following modulations—Satel 4FSK, PacCrest 4FSK (Transparent EOT/4FSK), PacCrest FST at 12.5Khz — the speed over the air is fixed at 9600bps. Whereas if you are using the following modulations — PacCrest GMSK (Transparent EOT/GMSK), or Trimtalk 450S at 12.5 Khz— the speed over the air is fixed at 4800bps.

If a low speed modulation type such as GMSK is used, the base radio transmitter is on-the-air for a longer time than a faster modulation. This means higher battery consumption and more heating of the radio itself.

Modulation

Modulation can be an even more complex subject and it has a major influence on both the speed over the air and the actual range of the radio equipment. Here is a quick and simplified explanation:

The most common modulation used today in UHF radios for RTK and other precision positioning applications is 4FSK (4-level Frequency Shift Keying). This means that the radio transmitter (base) transforms the NMEA data from the GPS into radio frequency variations that shift to 4 different points around its central working frequency. All the points must be contained within the 12.5Khz channel (up 11.25kHz usage is actually allowed by the FCC). This means that the transmitted frequency will constantly “shift” to 4 frequency points, both above and below the center frequency. As an example, the radio could represent different data patterns by transmitting at 2.5 and 5 kHz both above and below your central frequency. Each distinct frequency is interpreted as a binary pair (00, 01, 10, or 11) and the thusly the whole NMEA string of the GPS can be recomposed in the rover.

Some equipment offer even higher over-the-air speed by using more complex types of modulation (such as 8FSK, 16FSK). Some even use 32QAM, where not only frequency “shifts” but also “phase” variations are measured. Satel offers an internal OEM module, already in production and used by major GPS manufacturers, with 8FSK and 16FSK modulation and over-the-air speed up to 14400bps. This becomes useful when several constellations are received (for example GPS + GLONASS), which cause the radio to transmit more data. In order to be able to contain all data within 1 Hz (once a second) a higher over-the-air speed is desirable. The downside of higher modulation is that the receiver must work harder to detect very small variations, thus a stronger radio signal is required to counterbalance the environmental noise present in the air. Ultimately this means a decreased working range.

In Summary…

When considering over-the-air speed and higher modulation, factors such as battery consumption, radio heating, radio signal strength and desired working range should be reviewed. While higher modulation is generally ideal, the benefits may not be as impactful in areas of higher environmental noise. This trade-off may make a difference when analyzing your equipment and application.