IAS Gyan

Daily News Analysis


25th July, 2023 Security

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  • Indian Navy has begun equipping its warships with 'Made in India' Software-Defined Radio.

All about Software Defined Radio (SDR)

  • Software Defined Radio (SDR) is commonly defined as a “Radio in which some or all of the physical layer functions are software-defined”.
  • SDR technology uses software, instead of conventional hardware, to perform radio-signal processing functions.
  • Filters, error correction, synchronizers, modulators/demodulators, and frequency tuners used in conventional systems can all be written in software. Software-defined devices can be reconfigured to adapt to changing product requirements.
  • Unlike traditional radio communication systems, these radio devices are highly flexible and versatile. This is an emerging technology used to connect our ever-increasing wireless world.
  • While the term SDR refers to radio systems, the concept of processing signals in software rather than through hardware components is applicable to many more systems such as Radar, Automobile, Robotics, Electronic Warfare. A more generic term could be Software Defined Systems, or SDS.
  • SDRs work much like desktop computing where a single hardware platform can carry out many functions based on the software applications loaded. SDRs use high-speed reprogrammable devices such as Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), or General-Purpose Processors (GPPs), to execute tasks performed by hardware in conventional radio systems.
  • The system’s software-based filtering algorithms configure radio parameters such as operating modes, frequency, and modulation, eliminating the need for hardware components such as mixers, filters, amplifiers, modulators, and demodulators. This type of design results in a radio which can receive and transmit different radio protocols simply by changing software, providing the flexibility needed to efficiently use the radio frequency spectrum and expand a radio’s capabilities without the need for hardware updates.
  • SDR technology addresses the exponential growth by which people need to communicate. Data, voice, video, messaging, command and control, emergency response communications, etc. are all-encompassing communication mechanisms currently within the SDR domain. SDR is a solution to competing demands about providing greater access to communication means while keeping a tap on the equipment costs. SDR is a flexible and cost-efficient solution where benefits can be realized by service providers, product developers and even reaching end users.


  • Below are several key features and benefits of using SDR:
    • Reduce development cost and time to market by integrating software blocks rather than hardware redesign.
    • Reduce innovation cycle.
    • Protection against hardware obsolescence.
    • In-field updates/upgrade of system capability via software download.
    • Single hardware platform can support multiple communications protocols via software application loads.
    • Multi-purpose platform supporting multiple application domains (e.g. Radio/EW).
    • Development of domain specific applications can be initiated on personal computers.

'Made in India' Software-Defined Radio

  • Indian Navy has begun equipping its warships with 'Made in India' Software-Defined Radio.
  • Equipped with several multimedia capabilities, the indigenous SDR provides real-time voice, data and video information.
  • The Navy’s Weapons and Electronics Systems Engineering Establishment (WESEE) has indigenously designed and developed three types of SDRs – SDR NC, SDR-Tac (tactical), and SDR-NG.


  • The SDR Naval Combat (NC) has already been fitted in all Navy warships and is reportedly functioning well.

SDR-Tac (Tactical)

  • The Software-Defined Radio Tactical (SDR-Tac) has been installed in most of the warships.
  • The SDR-Tac is a four-channel multi-mode, multi-band, 19-inch rack-mountable, ship-borne software-defined radio system.
  • It is intended to serve ship-to-ship, ship-to-shore, and ship-to-air voice-data communication for network-centric operations.
  • It supports the simultaneous operation of all four channels covering V/UHF- and L-Band. This SDR system houses multiple types of waveforms for narrow-band and wide-band applications.
  • Each ship will act as a relay wherein the data can jump from one ship to another. To transfer voice, data or video, the link device picks up the best-suited available network. It ensures that data reaches its destination.

SDR Fighter Aircraft (FA)

  • The device is in the final stage of development and trials will be completed within a year's time.
  • These software-based communication systems will replace all hardware-based legacy communication systems in the years to come.

How will the indigenization of this critical instrument help the Armed Forces?

  • This SDR is used by the forces for transferring rates of voice, data, and video information.
  • Troops on the ground that are carrying handheld portable SDR versions, will be able to integrate with higher echelons to achieve real C4I capability.


C4I stands for Command, Control, Communications, Computers (C4) and Intelligence.

Advanced C4I capabilities provide an advantage through situational awareness, knowledge of the adversary and environment, and shortening the time between sensing and response. C4i's interoperable communications solutions are used by defence, governments and industry in more than 35 countries. C4i products enable rapid response times, interoperability and flexible asset utilization, and provide customers with ongoing cyber security protection.

Importance: Operations in the war on terrorism have demonstrated the advantages of timely and accurate information, while at the same time reinforcing the need for even greater joint, interoperable command, control, communications, computers, intelligence.

  • Now with the indigenised SDR technology, the possibility of Swarms of Drones operating in future battlefields seems a possibility.
  • Indigenization of the SDR technology is an important milestone which is important for achieving ‘Atmanirbhar Bharat’ in this field.

‘Drone Swarm Technology’

SWARM stands for “Smart War-Fighting Array of Reconfigured Modules.” The fundamental ‘Drone Swarm Technology’ centers around the capacity of a large number of drones, often in the mini/micro category, to independently make decisions based on shared information, and has the potential to transform conflict dynamics.

Swarm drones are multiple unmanned aerial flying platforms integrated as a single networked system self-contained for communication, reconnaissance and weapons/munitions to strike an enemy target.

The fact that components of the swarm can communicate with one another makes the swarm different from just a group of individual drones. Communication allows the swarm to adjust behavior in response to real-time information. Drones equipped with cameras and other environmental sensors (“sensor drones”) can identify potential targets, environmental hazards, or defenses and relay that information to the rest of the swarm. The swarm may then maneuver to avoid a hazard or defense, or a weapon-equipped drone (an “attack drone”) may strike the target or defense. Real-time information collection makes drone swarms well-suited for searching over broad areas for mobile or other hard-to-find units. Such a concept increases the probability of success of a mission.


Advantages Offered by Swarm Drones

Greater Survivability as the drones are difficult to detect hence chances of their survival is far greater as compared to manned aircraft. Similarly, being a network of weapon systems of multiple drones, even if they get detected and a few of them shot down, the function of the destroyed is taken over by other UAVs in the Swarm.

Cheaper Options to Armed Forces especially that do not enjoy conventional weapon superiority over their adversaries such as India over China.

Disruptive Effect against Ground based Weapon Systems. During the Nagorno-Karabakh conflict the Armenian tanks, Mechanised Infantry vehicles, artillery guns and limited Air Defence weapon systems were picked up and destroyed like ninepins by the Azeri drones supplied by Turkey and Israel thus proving a point that efficacy of such weapons. It also gives an opportunity to countries like India to redefine their force structuring and military capability development. The Nagorno-Karabakh conflict has proven that a small conventional force led by persistent drone attacks is not only a lethal and potent option but also a cheaper option.

Limited effect of Terrain. The drones are able to overcome the terrain and camouflage advantages of the ground forces through onboard sensors and reconnaissance equipment of the drones. Similarly, with loiter capability and mass drone employment the dispersion tactics are also neutralized.


Vulnerability and usage

Drone swarms are particularly vulnerable to electronic warfare attacks. Because drone swarms are dependent on drone-to-drone communication, disrupting that signal also disrupts the swarm. As swarms become more sophisticated, they will also be more vulnerable to cyberattack. Adversaries may attempt to hijack the swarm by, for example, feeding it false information, hacking, or generating manipulative environmental signals. Although numerous counter-drone systems are in development, current defenses do not appear sufficient and even promising systems will face scalability challenges, from deployment allocation to training, in the system’s use.

Analysts are divided on whether drone swarms offer significant cost benefits. Ultimately, the cost and its relevance depend in part on what role the swarm will play and what alternatives are available.

Drone swarms can be cost-effective on the balance if they meaningfully increase the survivability of more expensive or particularly crucial platforms, such as aircraft carriers or nuclear deterrent forces.

Drone swarm technology could have a significant impact on every area of military competition, from enhancing supply chains to delivering nuclear bombs.

Drone swarms offer significant improvements to both nuclear offense, the ability to successfully deliver a warhead to a target, and defense, the ability to prevent successful delivery and mitigate consequences.

Drone swarm technology is likely to encourage chemical and biological weapons proliferation and improve the capabilities of states that already possess these weapons. Terrorist organizations are also likely to be interested in the technology, especially more sophisticated actors like the Islamic State, which has already shown interest in drone-based chemical and biological weapons attacks. Drone swarms may also aid counter-proliferation, prevention, and response to a chemical or biological attack.

Sensor drones could collect environmental data to improve targeting, and attack drones could use this information in the timing and positioning for release, target selection, and approach.

Instead of spraying large masses of agent, drones could search for and target individuals or specific vulnerabilities such as air ventilation systems.

Drone swarms enable the use of combined arms tactics. Some attack drones within the swarm could be equipped with chemical or biological payloads, while others could carry conventional weapons. Although combined arms tactics are possible with current delivery systems, drone swarms allow much closer integration between conventional and unconventional weapons.

At the same time, drone swarms may also help prevent and respond to chemical and biological weapon attacks. Drone swarms could aid counter-proliferation efforts by, for example, coordinating searches for previously unknown chemical and biological facilities to secure stockpiles after a war. They could similarly coordinate searches along national borders to identify potential smuggling activity. Notably, swarms could serve as mobile platforms for chemical or biological detectors with different types of sensors to mitigate false positives. If an attack is successful, drones could coordinate mapping of affected areas to help guide responders. Drones could even have sprayers to help clean up after an attack, without risking harm to humans. 

Where does India Stand?

India recently demonstrated a swarm drone technology demonstration with Quadcopters on Army Day 2021. However small it may be but it has definitely indicated the intent of the Indian Armed Forces to move in this direction. It is the next frontier of warfare and we better be amongst the leaders in this domain. While there are a number of strategic lessons to be learnt from the Nagorno- Karabakh conflict, it is the military lessons highlighted above that should be of concern for us. India is deadlocked into perpetual conflict with Pakistan which greatly resembles the setting of the Nagorno-Karabakh conflict. Moreover, in recent times India is dealing with an aggressive and expansionist China and locked into a prolonged eyeball-to-eyeball conflict in Ladakh whose prognosis remains uncertain. We must also be cognizant of the fact that China today enjoys a significant edge in drone technology in fact it is almost in league with the world leader the US.

So where does India stand?

Sadly, while a number of startups have sprung up in this sector, we have a long way to go. A decisive public-private partnership backed strongly by the Ministry of Defence in collaboration with the world leaders (USA, Israel or UK) in this technology is the only way to catch up with China. Fortunately, in keeping with the above approach India has also commenced development of such a system in collaboration with the US as part of the 2 Plus 2 Defence Technology and Trade Initiative (DTTI). Meanwhile, HAL is also working in collaboration with a startup “New Space Research Technology.” The proposed system is named as ‘Air Launched Flexible Asset-Swarm’ (ALFA-S). It is likely to be a 1 – 2 meters long canister-based drone capable of being launched from air crafts/helicopters.  India must ensure that the “Swarm Drone Attack System” is based on the principles of the size of the swarm, survivability of the drones and the mix of the various types of drones in operations both for conventional and unconventional threats. Likewise, based on this emerging frontier of warfare India should review its warfighting doctrine, concepts, and capabilities, and modify its force structure. It is a highly competitive and devastating battlefield of the future and we need to match up to the changing dynamics of warfare and technologies associated with it.


Q. Drones are disruptive, drone warfare is asymmetric, much like guerrilla warfare, and the emerging drone swarm capability holds the potential of being a strategic asset in future warfare. Where does India stand in this context? Discuss.


Q. Consider the following statements with reference to Software-Defined Radio.

1.    Software-Defined Radio provides real-time voice, data, and video information.

2.    Software-Defined Radio eliminates the need for components such as mixers, filters, amplifiers, modulators, and demodulators.

3.    In Software-Defined Radio single hardware platform can support multiple communications protocols via software application loads.

4.    India's Software-Defined Radio Tactical (SDR-Tac) houses multiple types of waveforms for narrow-band and wide-band applications.

Which of the above statements is/are incorrect?

(a) 1 only

(b) 2 and 3 only

(c) 3 and 4 only

(d) None of the above.

Correct Answer: (d) None of the above.