Here is a chart listing some of the prominent Satellite IoT operators and the connectivity protocols they use. It includes both frequency bands (S-band, UHF, L-band, etc.) and specific communication protocols (e.g., LoRaWAN).
| Satellite IoT Operator | Frequency Band | Connectivity Protocol |
|---|---|---|
| Lacuna Space | S-band, ISM | LoRaWAN |
| Myriota | UHF | Proprietary Protocol |
| Astrocast | L-band | Proprietary IoT Protocol |
| Kepler Communications | VHF, UHF, Ku-band | Cellular IoT, Custom |
| Fleet Space | S-band | LoRaWAN, Proprietary |
| Hiber (Hiberband) | L-band | Proprietary Protocol |
| Sateliot | L-band, S-band | 5G NB-IoT |
| OQ Technology | L-band, S-band | 5G NB-IoT |
| Swarm Technologies | ISM | Custom Swarm Protocol |
| Inmarsat | L-band, S-band | BGAN, IoT Data Protocol |
| Iridium | L-band | Iridium Short Burst Data (SBD) |
This table covers a mix of frequency bands and communication protocols highlighting each operator’s approach to IoT connectivity.
Key Protocols:
- LoRaWAN: Long Range Wide Area Network used for low-power devices, common in ISM bands.
- Proprietary Protocol: Custom protocols developed by operators to optimize satellite IoT.
- NB-IoT (Narrowband IoT): 5G cellular technology adapted for satellite connectivity.
- ISM (Industrial, Scientific, and Medical Band): 868-915 MHz
- S-band: 2-4 GHz
- L-band: 1-2 GHz
- VHF (Very High Frequency): 30-300 MHz
- UHF (Ultra High Frequency): 300 MHz – 3 GHz
- Ku-band: 12-18 GHz
VHF Band: Operating between 30 and 300 MHz, VHF signals have longer wavelengths compared to higher frequency bands, making them ideal for short-range communications in space, such as Low Earth Orbit (LEO) missions. Their good propagation characteristics also facilitate effective inter-satellite links and reliable communication with ground stations.
UHF Band: Spanning 300 MHz to 3 GHz, UHF bands are crucial for transmitting data between spacecraft and ground stations. Due to their ability to penetrate the ionosphere, UHF signals ensure reliable and efficient communication over long distances. Their shorter wavelengths compared to VHF allow them to carry more data and maintain clear line-of-sight transmissions.
L-Band: Ranging from 1 to 2 GHz, the L-band is widely used for mobile services, satellite navigation (e.g., GPS, Galileo, GLONASS), telecommunications (e.g., Iridium, Inmarsat), aircraft surveillance, amateur radio, broadcasting, and radio astronomy. Known for its capability to penetrate the atmosphere and withstand adverse weather conditions such as heavy rain and fog, the L-band is well-suited for critical applications, including emergency communications and safety operations.
S-Band: Covering 2 to 4 GHz, the S-band is commonly employed for telemetry, tracking, and control (TT&C) of satellites, as well as for weather radar, radio navigation systems, and space research. It offers a good balance between data rate and atmospheric penetration, making it versatile for a variety of communication and monitoring purposes.
C-Band: Operating from 4 to 8 GHz, the C-band has been a cornerstone of satellite communication since the early days of space exploration. It is highly reliable for earth-to-space communication, as it effectively penetrates rain, snow, and other atmospheric conditions.
X-Band: Spanning 8 to 12 GHz, the X-band is valued for its high data rates and precision, making it ideal for radar communications and specific scientific instruments in space. It is less affected by rain attenuation compared to K-bands, making it suitable for high-priority missions requiring precise targeting.
Ku-Band: Operating between 12 and 18 GHz, the Ku-band is extensively used for high-powered satellite communications, including television broadcasting and broadband internet. Its greater bandwidth compared to lower frequency bands supports the transmission of large volumes of data.
Ka-Band: Situated between 26.5 and 40 GHz, the Ka-band occupies the upper portion of the microwave spectrum. It provides extensive bandwidth, ideal for data-intensive applications such as high-speed internet services and high-definition satellite television.
ISM Band: Covering 868-915 MHz and other regional frequencies, the ISM (Industrial, Scientific, and Medical) band is primarily used for low-power, short-range communication technologies like LoRa, Wi-Fi, and Bluetooth. It is widely used in both terrestrial and satellite IoT applications due to its unlicensed nature, making it accessible for various industrial and scientific uses.
The choice of frequency profoundly affects the performance of a satellite communication system, particularly its data rate—measured in bits per second (bps)—which represents how much information can be transferred between a satellite and its ground station over time. Higher frequencies, such as those in the S, X, and Ka bands, excel at this, allowing more data to be transmitted because they can accommodate more signal cycles within a given time frame. This translates to greater bandwidth, enabling a broader range of frequencies to be utilized simultaneously for transmitting vast amounts of data.
Higher frequencies come with shorter wavelengths, allowing for the use of more sophisticated modulation techniques that can encode multiple bits per cycle, exponentially increasing data throughput. On the other hand, lower frequencies, such as those in the ISM, VHF and UHF bands, are not optimized for high-speed data transfer. Instead, they’re used for applications where data speed isn’t a priority, such as basic telemetry or command and control in Low Earth Orbit (LEO) missions. These bands form the baseline for space communications, adept at maintaining robust connections over long distances despite their limited data capacity.
When the mission calls for moving large volumes of data—such as high-resolution images or complex telemetry—S and X bands are preferred, thanks to their higher data rates and moderate resistance to atmospheric interference. For interplanetary communications or deep-space missions, the Ku and X bands take the spotlight, offering high-powered, focused beams that ensure reliable data flow across vast distances.
The ISM band, UHF and L-Band are robust for sending lower rate data from IoT sensors and devices to low earth orbit satellites. These are ideal for simple IoT data points such as temperature, pressure, humidity etc. S and X bands are also significant in specialized applications because they provide a sweet spot between data rate and robustness. They are ideal for point-to-point communications, such as between satellites or from a satellite to a specific ground station. However, their higher sensitivity to atmospheric conditions—like rain fade and ionospheric absorption—can be a double-edged sword. This sensitivity stems from the fact that at these frequencies, electromagnetic waves interact more with atmospheric particles, causing signal attenuation and scattering.
Ultimately, the selection of frequency bands is a balancing act. Lower bands sacrifice speed for reliability, while higher bands offer blazing-fast data rates but demand careful planning to mitigate atmospheric challenges. Each frequency band has its unique role, sculpting the landscape of satellite communications in space and beyond.