Short-range radio applications – Maximum use of Spectrum for public good

Short-range Radio Devices or SRDs are assuming crucial importance for citizens as well as for specialized use cases like medical implants, assistive listening devices, smart grids like gas, water, electricity grids, and transportation

There are numerous applications of radio services that go beyond the simple voice and data provided by Public Telecom Service Providers (TSPs). Wireless connectivity over short distances, at low power can be used to bring many societal applications. In general, these services are provided by Short-range Radio Devices (SRD)1.

SRDs are assuming crucial importance for citizens as well as for specialized public and private sector use cases. Machine-to-Machine (M2M) communications and Internet of Things (IoT) employ SRDs and Ultra-Wideband (UWD)2 devices. Digital India has a wide-spread need for ubiquitous connectivity applications for both rural and urban needs. Whether smart villages, smart cities, smart communities, smart homes or disaster management, the use cases are diverse and many.

SRD devices, consuming low power and operating across short ranges, include medical implants, assistive listening devices, devices for smart grids (electricity, gas, water), multimedia, radio-determination devices, transport telematics and many.

More specifically, the devices which we commonly use for bluetooth, cordless, audio-video systems, wireless-car keys, car parking radars, RFID devices in malls & logistics, wearable radio devices, sensors for agriculture, transport safety, health monitoring devices, factory monitoring of machines & gears, indoor positioning and so on are all within this category of devices. Ultra-Wideband devices have many industrial and public applications including ground probing radars, wireless structural integrity testing.

Many of us use such SRDs regularly in our day to day life. But very few have any knowledge about the spectrum or the radio frequency utilized. These frequencies are a license exempt resource and have made these applications and devices possible for public convenience and safety. Enhancing the quality of life manifold.

Though not exhaustive the following categories are amongst those regarded as SRDs

Telecommand: The use of radiocommunication for the transmission of signals to initiate, modify or terminate functions of equipment at a distance.

Telemetry: The use of radiocommunication for indicating or recording data at a distance.

Voice and video: In connection with SRDs, voice covers applications like walkie-talkie, baby monitoring and similar use. Citizen band (CB) and private mobile radio (PMR 446) equipment is excluded.

Equipment for detecting avalanche victims: Avalanche beacons are radio location systems used for searching for and/or finding avalanche victims, for the purpose of direct rescue.

Railway applications: Applications specifically intended for use on railways comprise mainly the following three categories:

Automatic vehicle identification: The automatic vehicle identification (AVI) system uses data transmission between a transponder located on a vehicle and a fixed interrogator positioned on the track to provide for the automatic and unambiguous identification of a passing vehicle.

Balise system: Balise is a system designed for locally defined transmission links between train and track. Data transmission is possible in both directions. The physical data transmission path length is of the order of 1 m, i.e. it is significantly shorter than a vehicle.

Loop system: The loop system is designed for the transmission of data between train and track. Data transmission is possible in both directions. There are short loops and medium loops which provide for intermittent and continuous transmissions.

Road transport and traffic telematics: Road transport and traffic telematics (RTTT) systems are defined as systems providing data communication between two or more road vehicles and between road vehicles and the road infrastructure for various information-based travel and transport applications, including automatic toll-collection, route and parking guidance, collision avoidance and similar applications.

Equipment for detecting movement and equipment for alert: Equipment for detecting movement and equipment for alert are low power radar systems for radio determination purposes. Radio determination means the determination of the position, velocity and/or other characteristics of an object, or the obtaining of information relating to these parameters, by means of the propagation properties of radio waves.

Alarms

Alarm in general: The use of radio communication for indicating an alarm condition at a distant location.

Social alarms: The social alarm service is an emergency assistance service intended to allow people to signal that they are in distress and allow them to receive the appropriate assistance.

Model control: Model control covers the application of radio model control equipment, which is solely for the purpose of controlling the movement of the model (toy), in the air, on land or over or under the water surface.

Inductive applications: Inductive loop systems are communication systems based on magnetic fields generally at low RF frequencies. Inductive applications include for example car immobilizers, car access systems or car detectors, animal identification, alarm systems, item management and logistic systems, cable detection, waste management, personal identification, wireless voice links, access control, proximity sensors, anti-theft systems including RF anti-theft induction systems, data transfer to handheld devices, automatic article identification, wireless control systems and automatic road tolling.

Radio microphones: Radio microphones (also referred to as wireless microphones or cordless microphones) are small, low power (50 mW or less) unidirectional transmitters designed to be worn on the body, or handheld, for the transmission of sound over short distances for personal use. The receivers are more tailored to specific uses and may range in size from small hand units to rack mounted modules as part of a multichannel system.

RF identification systems: The object of any RF identification (RFID) system is to carry data in suitable transponders, generally known as tags, and to retrieve data, by hand- or machine-readable means, at a suitable time and place to satisfy particular application needs. Data within a tag may provide identification of an item in manufacture, goods in transit, a location, the identity of persons and/or their belongings, a vehicle or assets, an animal or other types of information. By including additional data the prospect is provided for supporting applications through item specific information or instructions immediately available on reading the tag. Read-write tags are often used as a decentralized database for tracking or managing goods in the absence of a host link.

Ultra low power active medical implant: The ultra-low power active medical implant (ULP-AMIs) is part of a medical implant communication systems (MICS) for use with implanted medical devices, like pacemakers, implantable defibrillators, nerve stimulators, and other types of implanted devices. The MICS uses transceiver modules for radiofrequency communication between an external device referred to as a programmer/controller and a medical implant placed within a human or animal body.

Wireless audio applications: Applications for wireless audio systems include the following: cordless loudspeakers, cordless headphones, cordless headphones for portable use, i.e. portable compact disc players, cassette decks or radio receivers carried on a person, cordless headphones for use in a vehicle, for example for use with a radio or mobile telephone, etc., in-ear monitoring, for use in concerts or other stage productions.

RF (radar) level gauges: RF level gauges have been used in many industries for many years to measure the amount of various materials, primarily stored in an enclosed container or tank. The industries in which they are used are mostly concerned with process control. These SRDs are used in facilities such as refineries, chemical plants, pharmaceutical plants, pulp and paper mills, food and beverage plants, and power plants among others.

From time to time, certain bands are made license exempt to enable rollout of other new services for the society and public good.

License Exempt Bands for SRDs UWDs (2018)

The NFAP (National Frequency Allocation Plan) 2018, under Annexure 1, lists bands offered as license exempt for operation of specific applications at very low powers. Till 2014, there were total 9 bands delicensed or made license exempt for a few applications. It was always like opening up one or two bands for such applications despite availability of global device ecosystem.

The objective of all the spectacular spectrum reforms by the Department of Telecommunications (DoT) post 2015 was to infuse more consumer and industrial services taking the advantage of well-developed global device ecosystem. As a big bang reform, in 2018, the DoT made over 40 bands license exempt for several innovative consumer and industrial radio services (Ref. Table below).

The delicensing norms also took measures to protect other radio services in the bands, wherever necessary. DoT has mandated global standards / technical requirements for these license exempt services on non-interference and non-protection basis to protect licensed services. The SRDs make use of various technical mechanisms such as Listen Before Talk, proximity, Low Duty Cycle (LDC) / low active time, Transmit / Total Power Control (TPC), Dynamic Frequency Selection (DFS), Detect and Avoid (DAA) mitigation among others.

Market reports indicate that post 2018, several thousands of device models have obtained ETA (Equipment Type Approval) from DoT indicating mega rollout of such applications for public and industrial use. It means, more services, indigenous development, more jobs and most importantly the free spectrum is enabling maximization of socioeconomic benefits contributing for country’s GDP growth in a big way.

1. The ITU Report SM. 2153-8 defines that the term ‘short-range radio device’ (SRD) is intended to cover radio transmitters which provide either unidirectional or bidirectional communication and which have low capability of causing interference to other radio equipment. Such devices are permitted to operate on a non-interference and non-protected basis. SRDs use either integral, dedicated or external antennas and all types of modulation and channel pattern can be permitted subject to relevant standards or national regulations. 

2. “ultra-wideband device or equipment” means a short-range device having a bandwidth of at least 50 MHz;

3. Car immobilisation, animal identification, alarm systems, cable detection, waste management, personal identification, wireless voice links, access control, proximity sensors, anti-theft systems, including radio frequency anti-theft induction systems, data transfer to hand-held devices, automatic article identification, wireless control systems and automatic road tolling

4. Active medical implant device covers the radio part of active implantable medical devices that are intended to be totally or partially introduced, surgically or medically, into the human body or that of an animal, and where applicable their peripherals.

5. Combined audio or video transmissions and audio or video sync signals, mobile phones, automotive or home entertainment system, wireless microphones, cordless loudspeakers, cordless headphones, radio devices carried on a person, assistive listening devices, in-ear monitoring, wireless microphones for use at concerts or other stage productions, and low power analogue FM transmitters

6. Radio communications systems that allow persons suffering from hearing disability to increase their listening capability. Typical system installations include one or more radio transmitters and one or more radio receivers

7. Used for determining the position, velocity and/or other characteristics of an object, or for obtaining information relating to these parameters.

8. Device that is using ultra-wideband technology for communication applications such as personal computers, handheld terminals, cable modems, set-top boxes, indoor access points etc.

9. System intended for location tracking of people or objects;

10. Device designed to detect the location of objects within a structure or to determine the physical properties of a material;

11. Material sensing device detects the location of objects within a building structure, or to determine the physical properties of building material;

By KISHORE BABU YGSC,

Deputy Director General (DDG), Standardization-R&D-Innovation, Department of Telecommunications   

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