The Ministry of Defence (MoD) and Defence Public Sector Undertaking (DPSU) Bharat Electronics Limited (BEL) has signed a contract for procurement of Software Defined Radio Tactical (SDR-Tac) worth over ₹1,000 crore, during the 'Bandhan' ceremony at Aero India 2021 at Air Force Station Yehalanka in Bangalore today.

The SDR-Tac, jointly developed by Navy, BEL, Defence Research and Development Organisation (DRDO) and DEAL, will bring strategic depth to the Armed Forces.

The delivery will take place within three years. The BEL is already supplying SDR-Naval Combat (NC) and SDR-Air is under user evaluation trial. The DRDO and BEL are planning to provide the latest SDR with security grading to the Armed Forces, said an official release.

What Is SDR-Tac?

The SDR-Tac is a four Channel Multi-mode, Multi-Band, 19’’ Rack mountable, shipborne Software Defined Radio system. It is intended to serve ship to ship, ship to shore and ship to air voice and data communication for network-centric operations.

It supports the simultaneous operation of all the four channels covering V/UHF and L Band. This SDR system houses multiple types of waveforms for narrowband and wideband applications.

The MANET waveforms are available in UHF and L-Band to support adhoc networking feature for net-centric operations. User evaluation trials covering exhaustive harbour phase and sea phase trials were completed successfully during May to June 2018 at Visakhapatnam for all waveforms including V/UHF and L-Band MANET waveforms under different network configurations.

Interoperability trials were also successfully carried out with all other form factors covering Airborne SDR-AR onboard Dornier Aircraft, SDR-Tac onboard INS Kirch in sailing mode, SDR-Manpack and SDR-Handheld. All the aspects were evaluated successfully by all user agencies of the Navy and clearance was accorded for procurement.

The Armed forces are in need of transition from the single purpose radio of the past to more flexible Software Defined Radios (SDRs) to serve most of their wireless communication needs. These SDRs will be backward compatible with existing Indian radios.

Different Service groups require different form factor radios for specific platforms and waveforms/applications. The SDRs allow the use of common waveform/application implementation methods for different form factors. They also allow the implementation of futuristic waveforms on the same hardware using software programmability, thus ensuring longer life and savings on cost.

A key factor in SDRs is that software programmability allows easy changes of the radio's fundamental characteristics such as modulation types, operating frequencies, bandwidths, multiple access schemes, source and channel coding/decoding methods, spreading/de-spreading techniques and encryption/decryption algorithms.

Traditional hardware-centric radios require hardware changes to modify these fundamental characteristics. Multiple types of radio equipment can be replaced with multi-mode, multi-band, multi-role SDR's of suitable form factors, the statement said.