This upgradation is to replace and modernise existing HF Broadcast Transmitting Stations (TS) at various locations in order to provide the Navy with long-range and reliable HF Broadcast communication

Photo Credit : Indian Navy,

The Indian Navy is upgrading its communications and has issued a Request for Information (RFI) to acquire approximately 50 advanced High Power HF Broadcast Transmission Systems (HPHBTS) as well as accessories, antennae systems and remote keying facilities.

This is to replace and modernise existing HF Broadcast Transmitting Stations (TS) at various locations in order to provide the Navy with long-range and reliable HF Broadcast communication. A senior officer said that the HF transmitter and receiving systems necessitate extremely large antennas that meet military standards.

The Navy requires an operating frequency range of 1.5 to 30 MHz. Its most common use is in long-distance communications, such as those used by the shipping and aviation industries, as well as radio amateurs and broadcasters all over the world. 

The function is accomplished by bouncing the signal off the ionosphere and back down to waiting receiving stations. It is sensitive to changes in the surrounding environment, which can result in fading and noise. The operational range ranges from 500 to several thousand kilometres.

“The purpose of modernising existing transmitting stations with more advanced HPHBTS systems is to enhance the capabilities of those transmitting stations so that they can provide higher data rates and more reliable HF digital broadcast communication for naval units both afloat and ashore around the world,” Girish Linganna said, Aerospace and Defence Analyst.

He further added that the system's capabilities include remote operations such as Morse keying and data communication, which would be performed from Broadcast Controlling Stations over naval terrestrial, Satcom or wireless networks using Transmitters and Antennae at Transmitting Stations.

The RFI mentions data transmission and file-sharing functions in addition to voice and CW operations. The system should be able to establish a communication network as well as provide a relay facility, allowing data to be re-sent immediately on the same or another frequency, depending on the situation. The proposal also mentions receiving data via the serial port on the built-in modem for the purpose of data communications.

The ECCM for electronic countermeasures for secure and jam-resistant voice and data links is also mentioned in the document.

Linganna said that It is necessary for the HPHBTS set to be capable of remote control via an external PC or laptop. The remote control laptop or desktop PC's printed circuit boards (PCBs) and application software must be compatible with the most recent operating system versions. The system should be able to operate remotely using the Navy's terrestrial and wireless technologies.

The equipment's overall lifespan should be at least 12.5 years from when it is delivered to naval transmitting stations. Each set is to be supplied with a consolidated set of Base and Depot (B&D) spares and an Onboard Ship (OBS) spares to ensure that the equipment can be maintained for an additional three to five years after the warranty has expired. The vendor must guarantee that any future changes to the system's software and hardware will be made available to the Navy.

Previously, the majority of communication sets in the VLF, V/UHF and HF frequency bands were imported and then created or provided as services by public sector organisations such as Hindustan Aeronautics Limited (HAL), Bharat Electronics Limited (BEL), ECIL and others through Transfer of Technology (ToT).