By Dr. Henrik Axelsson, CEO of KenCast

Military communications have come a long way since ancient times, when the Greek writer Aeneas Tacticus invented the hydraulic telegraph in the 4th century BC. This device used water buckets and rods with predetermined messages to convey detailed information over long distances, surpassing the limitations of torches and beacons that could only signal simple alerts.

Today, militaries need to transmit and receive large data files and video streams in real time, under challenging network conditions and to multiple fixed and mobile receivers. To achieve this, they need to use the most advanced communications technology available, such as algorithms that ensure secure and error-free delivery of data.

Covering the battlefield and beyond

During the most recent major conflicts — such as the war in Ukraine — the critical importance of verified, secure communications is abundantly clear. The importance and complexity of military communications have increased significantly in the past decades, as modern warfare has become more diverse and dynamic. Military forces need to share and access various types of data and multimedia products, such as unmanned aerial vehicle (UAV) video, imagery, intelligence, maps, weather, biometric data, and security and system software updates. These products can provide vital information for tactical and strategic decision-making, situational awareness and operational security. However, they also pose several challenges and risks for military communications, such as:

• The high volume and bandwidth requirements of the data and multimedia products, which may exceed the capacity and availability of the network resources.
• The adverse and unpredictable network conditions, such as interference, congestion, latency, packet loss or fragmentation, which may degrade the quality and reliability of the data transmission.
• The hostile and sophisticated threats from adversaries, such as jamming, hacking, deception or interception, which may disrupt or exploit the data transmission.
• The fact that the increasing speed and mobility of modern weapons and vehicles require faster and more reliable communications to keep up with the changing situations.
• The diverse and changing scenarios and environments, such as urban, rural, mountainous or maritime, which may affect the network performance and coverage.
• The fast and frequent movement of the data sources and destinations, such as aircraft, vehicles or soldiers, which may cause network instability and disconnection.

To overcome these challenges and risks, militaries need to use the best content distribution techniques that can ensure the secure and error-free delivery of data and multimedia products over satellite and other networks.

Time to ditch the ‘spray and pray’

Large-volume data and multimedia is typically sent over satellite in a military setting. Troops are often on the move or in makeshift locations in which the only way of receiving a reliable signal from another unit is from a satellite link. Moreover, these networks operate in a one-way transmission mode, where the sender does not receive any confirmation or response from the receiver. This means that the sender has no way of knowing whether the data was received correctly and completely, or whether it was corrupted or lost due to errors in the transmission channel.

To overcome this challenge, traditional methods relied on sending the same data multiple times, hoping that the receiver would eventually receive all the parts and reconstruct the whole file. This approach, known as carousel delivery or spray and pray, has a low probability of success and a high cost of bandwidth and time. It also becomes less efficient as the number of receivers increases, since each receiver may have different reception conditions and require different numbers of transmissions to receive the whole file.

A better solution to this challenge is to use a technique called forward error correction (FEC), which is a form of channel coding that adds redundant information to the original data before transmission, allowing the receiver to detect and correct errors without needing any feedback from the sender. FEC can improve the bit error rate and the data reliability of satellite communication, by reducing the number of transmissions and increasing the probability of successful delivery.

FEC can be thought of as a Sudoku puzzle, where the sender provides enough clues (parity bits) for the receiver to fill in the missing pieces (data bits) and complete the whole file. FEC algorithms use mathematical formulas to generate and decode the parity bits, ensuring that the receiver can recover the original data even if some parts are lost or corrupted.

However, not all FEC algorithms are the same, and some are more effective and efficient than others. The quality of FEC depends on several factors, such as the amount of redundancy, the error correction capability, the computational complexity and the adaptability to different channel conditions. Some common FEC techniques, such as Reed–Solomon or convolutional codes, may not be able to handle the high volume and variability of the data and multimedia products, or the high level and diversity of the network errors.

Therefore, defence forces need to use more advanced and robust FEC techniques, such as the digital delivery software developed by KenCast. Its patented Application Layer (AL)-FEC is applied across the entirety of the transmitted content, as opposed to other versions that can only correct very brief real-time errors. Accordingly, it adapts to the characteristics and conditions of the data and the network, and provides optimal performance and security for data transmission. It also supports multicast and broadcast transmission, which can enable efficient and scalable data delivery to multiple receivers.

Case study: Defense Information Systems Agency

One agency that required a reliable and guaranteed way of transmitting data was the US Defense Information Systems Agency (DISA), which in 1998 began to build out the Global Broadcast Service (GBS) to provide global connectivity via satellite to US joint forces in battle. Issues quickly emerged in the development stage, as personnel attempted to send encrypted content to troops on the move and into areas where atmospheric conditions were challenging. This was compounded by the impermissibility of a backchannel to validate received data — the military had little choice other than to spray and pray.

Having invited over a dozen major companies to address its need for secure and reliable delivery of critical content, DISA was impressed by the efficiency and operational effectiveness of AL-FEC as well as KenCast’s software suite of content delivery tools, known as Fazzt. KenCast was chosen to provide the content delivery solution for the GBS, working with Raytheon and then Lockheed Martin to integrate its software into the overall solution.

As the size of the GBS network has grown over the past 26 years, KenCast has been asked to add more servers and clients, along with continued technical support and feature upgrades. The company has also brought to market dozens of new AL-FEC-related patents, including versions specific to moving vehicles, terrestrial acceleration protocols and hardware appliances. Meanwhile, Fazzt has been used by various military and government customers to deliver large-volume data and multimedia products over satellite and other networks, while demonstrating its resilience and security against threats such as jamming, hacking and interception.

The better the algorithm, the better the delivery

It is important for militaries to remember that the better the algorithm, the higher the efficiency of error correction, the greater the reliability of delivery, the faster the speed for a complete transmission and the larger the cost savings on retransmissions. For any operation using this technology, it is important to know which level of FEC your network uses.

In conclusion, just as Aeneas Tacticus sought efficiency in his time, modern militaries continue to refine their communication strategies with technologies like AL-FEC and Fazzt. This commitment to innovation ensures that vital information flows seamlessly across the global theatre of operations, safeguarding missions and lives.

This article was originally published at Critical Comms magazine, which can be found here; How advanced comms give militaries an edge in the modern battlefieldHow advanced comms give militaries an edge in the modern battlefield :: Critical Comms

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