Long-Range Detection
Usual detection ranges for S-band usages reach 300 to 400 kilometers, while for some more advanced systems, this range can be extended beyond even 500 kilometers. The National Weather Service’s NEXRAD weather radar network uses the S-band, capable of monitoring rainfall intensities over 100mm per hour with precision, and tornado signals with wind speeds over 50 meters per second.
While the higher-frequency X-band provides clearer close-range imaging, its detection range only spans typically 40 to 60 kilometers. S-band radar is able to predict storm paths and intensity changes 6 to 12 hours earlier than X-band. According to NOAA, Hurricane Harvey caused more than $125 billion in economic losses in 2017.
Under extreme conditions of over 90% humidity and below 0°C, there is only a 2.3% signal attenuation for S-band radar, while the signal attenuation of C-band and X-band reaches up to 7.5% and 12%, respectively. Over 70% of major airports worldwide are using S-band for radar systems. Even with a disruption rate of up to 1%, these systems process thousands of flights daily.
The backbone communication link in the Galileo navigation satellite system was built on S-band frequencies and evidenced stable data transmission of 50 Mbps per second from above the Earth by 36,000 kilometers. S-band consumes less power so as to operate the long-distance data transmission by 30%. Satellites operating on S-band usually serve for 15 to 20 years, which is 25% more than that by ordinary communications satellites.
By comparison, S-band frequencies allow the system to lock onto over 100 targets in less than 5 seconds. The Aegis defense system also utilizes S-band radar, deployed for Japan’s Self-Defense Forces, and can monitor air and surface targets out to a 500-kilometer radius.
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Surveillance Applications
Over 60% of the deployed surveillance radar systems around the world currently operate on S-band frequencies. For example, the border security system installed along the border between the U.S. and Mexico intercepts over 2 million illegal entries each year. This S-band radar can locate targets from a distance of 70 to 100 kilometers away at accuracy levels greater than 95%, which is very high compared to conventional radar, with only 85% accuracy.
On any given day, the international airport sees over 100,000 passengers and upwards of 800 flight arrivals and departures. According to ICAO, runway incursions account for more than $1 billion in aviation losses annually around the world. Airports using S-band radar reduce incidents of this nature by over 40%.
With S-band radar, the position of every ship could be tracked in real time and collision warnings issued within 5 seconds for over 1,500 ships using the Port of Rotterdam in the Netherlands on any given day. The operator saves more than 5 million euros a year in accident-related costs.
According to the International Maritime Organization, over 1,500 maritime accidents occur every year worldwide, causing more than 5,000 deaths and disappearances. S-band radar can locate distress signals from vessels as far away as 300 kilometers with a detection accuracy error of less than 1 meter.
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WiFi Network Usage
The two well-known Wi-Fi frequencies are 2.4GHz and 5GHz. S-band formed the core technologies used in the 2.4GHz band. Besides that, it guarantees good Wi-Fi signal penetration through walls, doors, and furniture covers at a distance of 100-150 meters. On the contrary, it can serve around 30-50 meters via the 5GHz band.
Over 70% of homes and businesses in the world still operate on the 2.4GHz Wi-Fi band. For most daily applications, network speed and stability on 2.4GHz will suffice. The average household contains 15 to 20 devices that connect with a Wi-Fi network. If all use the same frequency at 2.4GHz, download speeds may fall from 100 mbps per second down to 20 mbps per second or even lower.
If, in an ordinary office environment, the router supports only the 5GHz band, the signal may be completely cut off when it passes through cement walls that are more than 10 cm thick. The signal attenuation of the 2.4GHz band is smaller, and after passing through two to three walls, the signal can still maintain a rate of transmission over 30 Mbps. Therefore, the coverage and stability of 2.4GHz Wi-Fi are better in big areas.
The Wi-Fi access points are in excess of 5,000 in airports serving daily traffic of over 100,000 passengers. Using the 2.4GHz band for dead zone coverage enhanced public Wi-Fi satisfaction in Heathrow Airport by more than 15%.
Over 15 billion IoT devices have been deployed so far globally, with projections of a surge to 50 billion devices by 2030. Most of the low-power and low-speed IoT devices rely on Wi-Fi technology utilizing the 2.4GHz band. Using 2.4GHz, IoT devices can make it through more than 2 years; the higher frequency connections of 5GHz and 6GHz would shrink this to 6-12 months. The cost of the Wi-Fi modules currently sits at around $2-5 for the 2.4GHz band, while modules supporting dual or tri-band upwards sell for more than $15-20.
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Household Devices
The heating efficiency of microwave ovens at 2.45GHz is more than 90%, while that of other frequencies is less than 60%. Signals should be able to penetrate obstacles; the signal attenuation rate in the 2.4GHz band is about 15% to 20%, compared with 30% to 40% in the 5GHz and 6GHz bands.
The single most advantage of remote controls, because S-band frequencies allow it, in transmission distance about 10 to 15 meters, infrared remote controls operate within the line of sight, and obstruction leads to signal failure.
In the year 2023, the smart home appliance market was over $32 billion and it will reach a value of $60 billion by 2028. More than 80% of the connectivity in these devices is based on S-band frequency. As compared to the high-frequency WiFi, S-band devices are less expensive. A major characteristic of baby monitors is that they usually have long standby batteries. S-band frequency devices consume low power, enabling such devices to work for 8 to 12 hours.
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Microwave Communication
S-band signals are less attenuated at 36,000 kilometers in the geostationary orbit. One S-band communication satellite can cover more than the diameter of 10,000 kilometers. The cost of the S-band microwave communication is 30% to 50% less than that of the fiber-optic networks. A typical microwave communication link takes 1 to 2 weeks to set up while the fiber-optic networks take months or more.
According to the ITU standards, the standard S-band microwave communication system can offer 50 to 100 km reliable transmission distance on the Earth’s surface. Using relay stations, the distance may extend between 300 to 400 km. The data transferring rate of S-band communications can reach 1Gbps to 2Gbps per second.
The WIN-T system by the U.S Army is highly dependent on S-band frequencies to have multi-node communications within 500 km. According to the U.S. Department of Defense, this system can operate more than 500 communication terminals simultaneously with a latency of less than 50 milliseconds. According to Boeing, the S-band communication applies to the aviation system failure rate below 0.01 percent, far lower compared to the traditionally used VHF communication systems failures of 0.1 percent. According to NASA, the S-band links in communication can support transmissions to as far as 300 million kilometers with a bit error rate less than 1%.
S-band frequencies in meteorological radar can detect precipitation particles larger than 10mm in diameter and update real-time rainfall distribution data every 5 minutes. S-band radar is more suitable for monitoring large-scale precipitation and storm systems. More than 75% of weather radar systems in the world use S-band communication technology, and S-band radar can predict storm paths 6 to 12 hours in advance.
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Keyless Entry Systems
It follows, therefore, that more than 80% of wireless keyless entry systems in the world use 2.4GHz wireless communication in connecting and unlocking devices. In general, S-band frequencies keyless system could easily identify the identity of a car owner within 3 to 5 meters in unlocking his car. According to the test report from Texas University, the success rate for unlocking keyless entry systems using S-band frequencies stands at as high as 99.8%, while all high-frequency systems generally stand between 95% to 97%. S-band frequency systems are even capable of yielding a high unlock success rate of up to 97% in the presence of more than 50 other wireless signals.
Generally, a smart lock system should work for 12-18 months on batteries. It is quite feasible to do this by using the 2.4GHz S-band frequency for communication in order to save power. Using a higher-frequency method of communication would decrease this to as little as 6-9 months. As an example, in a typical three-bedroom apartment of 120 square meters, the attenuation rate for 2.4GHz is around 20%, while that for 5GHz exceeds 35%.
It employs a combination of ultra-wideband (UWB) and S-band technology, accurately locating the key within 10 centimeters. According to the latest data from BMW, the new keyless system reduces relay attacks by over 80%.
Nowadays, S-band-based mobile unlocking systems have been implemented in over 60% of the high-end hotels around the world. S-band frequency is used for such systems since S-band is capable of offering stable signal transmission within the 5 to 10 meter radius.
It is estimated that a hotel spends US$20,000 to US$50,000 every year in maintaining and replacing keycards. These costs were reduced by more than 50% after S-band-based keyless systems had been implemented. The North American Hotel Association found that guest satisfaction has risen by 18% with an over 90% reduction in the loss or damage of keycards.
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Bluetooth Connectivity
The Bluetooth SIG states that over 6 billion devices around the world leverage Bluetooth for connectivity, with more than 90% of those using S-band frequencies to achieve wireless communication at shorter ranges.
The devices people commonly use are smartwatches, fitness bands, and wireless earphones; all these work on a single battery and may last from 7 to 14 days. This is because Bluetooth communication in the 2.4GHz S-band consumes only a few milliwatts of power while sending at 1Mbps to 2Mbps. With every higher frequency that is used in communication protocols, battery life is shrunk by 30% to 50%. One brand’s smartwatch can last up to 10 days on a single charge with the Bluetooth enabled, but if turned to Wi-Fi, the same device’s battery will shrink to about 3 days.
Because the 2.4GHz S-band is unlicensed globally, Bluetooth’s AFH technology can rapidly switch between 79 sub-frequencies with 1MHz separation. According to test results from Bluetooth SIG, AFH technology can reduce the error rate of Bluetooth communications from 10% down to below 1%.
For example, Apple AirPods Pro 2 uses S-band communication at 2.4GHz, while performance is optimized using the H1 chip. According to official data, the time of signal latency in headphones does not exceed 200 ms, though in traditional wireless headphones, this parameter lies between 300 and 500 ms.
In the in-car Bluetooth systems, they apply Bluetooth technologies based on 2.4GHz S-band to make stable the connection up to 120km/h with call dropouts less than 1% to maintain a firm call for either BMW or Audi.
By 2025, according to the WHO, more than 1.5 billion people will use Bluetooth medical devices for routine health monitoring. S-band low-power Bluetooth devices can have a battery life of 6 months to a year and have a data transmission error rate of less than 0.1% within a 10-meter range.
They are typically based on the 2.4GHz S-band to implement fast connections and low-latency control. Smart home appliances with Bluetooth connections have a failure rate about 15% to 20% lower than Wi-Fi, while the device startup time is reduced by over 30%.
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