frequency, and the sonar might be license produced in India with Indian designation SSSN-113. Countermeasures The frigate features the Russian-made TK-25E-5 integrated electronic warfare suite, which comprises a wideband electronic support measures system that has antenna arrays mounted in the superstructure and a multimode jammer. Four KT-216 decoy launchers, forming part of the PK-10 system, are fitted for soft-kill defence. A total of 120 120mm chaff and infrared decoy rounds are carried on board. Some ships of the class including INS Tabar have had their TK-25E-5 ESM suites replaced with BEL manufactured Varuna ESM systems with their distinctive circular housing located above the Fregat radar. Combat data system The Trebovaniye-M combat information and control platform is a fully distributed combat management system. It controls all platforms of attack and defence weapons, independently generates combat missions based on situation analysis, determines optimal number of missile firings, displays information on the state of ship-borne weaponry and transmits data to protection systems. Interconnected via an Ethernet LAN, Trebovaniye-M features eight T-171 full-colour operator workstations (with 18-inch colour flat panel displays) and three central T-162 servers. Individual items of combat system equipment interface to Trebovaniye-M via T-119 and T-190 bus interface units. Raw radar data is received through a T-181 data reception unit. Recent developments India and Russia are negotiating for building four more Talwar frigates for the Indian Navy. In September 2016, it was reported that India would acquire two s from Russia and remaining two will be built in India. The deal was signed in October 2016. These frigates are based on the Talwar class and were to be commissioned into the Russian Navy, but after the Ukrainian Conflict, Ukraine refused to supply any more engines for the Russian ships. So far, only two of the six have been commissioned by Russia. In August 2017, the Indian Defence Acquisition Council (DAC) cleared a proposal of Rs 490 crore to buy two gas turbines from Zorya-Mashproekt in Ukraine for the s being built in Russia. In October 2018, Indian Ministry of Defense signed a deal for US$950 million for procuring two s, Admiral Butakov and Admiral Istomin. The two frigates will be delivered to Indian Navy by 2022. A contract was signed between Rosoboronexport and Goa Shipyard for the construction of 2 frigates under license on 20 November 2018. The two frigates will be armed with Brahmos missile system and will include a