Overview:

The demand for radio spectrum has increased significantly because of the growing popularity of wireless communication services .The national telecom regulatory body, BTRC is responsible for managing and monitoring of radio spectrum usage efficiently and properly in Bangladesh.

Spectrum management requires radio frequency monitoring as an essential element. Measuring the spectrum occupancy is indispensable for planning future assignment of frequencies as well as for monitoring all kinds of emissions, measuring of their technical characteristics and locating their sources by using direction finding systems.

Spectrum Monitoring and Detection Directorate is always well informed on current developments of wireless technologies. Considering future developments, this department is prepared to work out solutions on spectrum issue that will fully meet future requirements in Bangladesh.

Spectrum Monitoring Objectives:

Spectrum Planning and Authorization are central functions supported by spectrum monitoring. Monitoring supplies information used in determining compliance with rules and regulation, such as license conditions, and in achieving compliance with technical and operational standards. It provides general measurements which are used by the spectrum managers to understand and plan frequency channel and band usage as well as confirm the effectiveness of current planning and authorization activities. Understanding the level of spectrum use or occupancy in comparison to assignments is important for efficient use of the spectrum resource. Spectrum monitoring provides statistical information on the technical and operational nature of spectrum occupancy. Conversely, spectrum authorization and spectrum engineering functions support spectrum monitoring by providing accurate, complete and timely information on current assignments and licenses.

The overall goal of spectrum monitoring activities is to support the proper functioning of the general process of spectrum management. Central objectives for spectrum managers include the following:

• Spectrum efficiency in determining planned and actual frequency usage and occupancy, assessing availability of spectrum for future uses;
• Compliance with national spectrum management regulations to shape and sustain radio environments and user behaviour, maximizing the benefit of the spectrum resource to society;
• Resolution of interference problems for existing and potential users. The facilities, equipment and approach employed in achieving these objectives will depend heavily on current use, congestion, technical capacity of the spectrum management operations.

The facilities, equipment and approach employed in achieving these objectives will depend heavily on current use, congestion, technical capacity of the spectrum management operations.

Function of Spectrum Monitoring and Detection Directorate:

The Spectrum Monitoring and Detection Directorate ensures effective, efficient, and prudent use of the radio spectrum in the best interest of Bangladesh. Spectrum monitoring is also necessary to assist overall spectrum management significantly.The main functions of this department are described as below:-

• Measurement and analysis of spectrum according to ITU handbook and recommendations.
• Regularly monitor the assigned frequency of operator in the legal frame.
• Monitoring & identification of interfering signals; such as: - harmful interference, cross border interference, etc.
• Assist in resolution of frequency interference to other services.
• Detect and tracking (direction finding-DF) the source of illegal transmissions or spurious emissions.
• Assist in ensuring acceptable reception of public broadcasting.
• Monitoring transmitter technical parameter and verify compliance to technical standards.
• Performing spectrum occupancy measurement and transmission coverage to assist spectrum management planning.
• Marinating a database of Spectrum assignment and permitted wireless equipment by using Automated Spectrum Management System (ASMS).
• Monitoring and investigation to gather evidence for enforcement function.
• Providing monitoring data to support the ITU for resolving international issues.

Strength of Spectrum Monitoring and Detection Directorate:

Spectrum monitoring is important for the efficient use of the radio-frequency spectrum. The spectrum monitoring system at BTRC provides optimum efficiency by combining up-to-date radio-monitoring equipment with powerful spectrum analysis software. The Strength of Spectrum Monitoring and Detection Directorate of BTRC as follows:-

• The Spectrum Monitoring & Detection System is compliant with the latest ITU-R recommendations.
• The Spectrum Monitoring & Detection System of BTRC consist of following tools:-
  • Fixed Monitoring System,
  • Mobile Monitoring System,
  • Portable Monitoring System, 
  • Advance Antenna Receiver System, and
  • Wideband Portable Spectrum Analyzer.
• Spectrum monitoring station covers the important regions of Bangladesh for the purposes of radio spectrum monitoring periodically. There are :-
  • Central Fixed Monitoring Station(FMS) established in Dhaka for spectrum monitoring and coordinating with other stations.
  • Five Fixed Monitoring Stations (FMS) has been established in Chittagong, Khulna, Shylhet, Bogra and Rangpur.
  • Five Mobile Monitoring Stations (MMS) are always available to detect illegal use of radio frequency and finding the source of frequency interference and resolving frequency issues immediately throughout the country. It is also used to measure and display the field strength & occupancy of all frequencies.
  • A Portable Monitoring Station (PMS) is used for operation, where no other system can access. Operation work with the equipment on the move and perform different measurements including homing tasks.
  • All monitoring stations are integrated in private and public communications networks for countrywide spectrum monitoring and detection in Bangladesh.
  • Apart from this, the commission has planned to establish 10 (ten) more Fixed Monitoring Station (FMS) in the other districts within a few years.
  • The commission has also planned to upgrade the existing system to more capable and powerful system to keep up with future requirements of spectrum monitoring.
• Direction finding (location of transmitter), frequency measurement, spectrum occupancy, spectrum analysis and field strength measurement equipment are valuable aids for spectrum monitoring and detection.To perform these activities, Spectrum Monitoring Directorate has very cutting-edge Spectrum Processor System, Advance Antenna System with built-in Geographical Information System (GIS) & Global Positioning System (GPS).
• Spectrum Monitoring and Detection Directorate has established a Laboratory room, which is equipped with radio frequency analysis tools and advance technologies to facilitate radio research and development in Bangladesh.

Figure: Location of Fixed Monitoring Station (FMS) in Bangladesh.

Figure: Mobile Monitoring Station (MMS) for Spectrum monitoring and detection.

Direction finding of illegal transmissions (tracking the source):

The different monitoring stations are used to detect interfering and unauthorized RF transmissions, monitor emergency frequencies and protect large-area, high-value assets.

The Spectrum Monitoring and Detection Directorate of BTRC possess a high performance Spectrum Monitoring Systems (SMS) with monitoring capability and direction finding (DF) antennas.

The advanced software application provides, a complete command and control of spectrum monitoring and direction finding (DF) operations and is fully compliant with the applicable ITU recommendations and the 2011 Spectrum Monitoring Handbook. To find the location of legal and illegal transmitter, it is required at least two MMS to find the exact location of source of transmission. The following figure shows the detection of an illegal transmitter by using DF Antenna, GPS, Digital Map and Spectrum analyzer.

Figure: Finding the location of illegal transmitter through DF application (the cross section point on digital map).

Solving Interference Problems:

The Spectrum Monitoring and Detection Directorate of BTRC perform routine measurements frequently by using FMS & MMS. These include measurements on licensed transmitters and also can search for and identify non licensed transmitters, which cause frequency interference. The main steps for resolving interference problems are:

• Communication and Acknowledgement of an interference problem by a user;
• Diagnosis of an interference problem;
• Identification through monitoring and measurement of the potential source of interference;
• Confirmation of the source of interference and communication with the people responsible;
• Determining steps to correct and mitigate interference such as the use of filters, reducing transmits power, re-locating transmit antennae, and changing transmit frequencies or stop the transmission in case of illegal usage.

Figure: Analysis of frequency interference by using Spectrum Monitoring Application.

Automated Spectrum Management System (ASMS):

ASMS comprises of Database Server system and client software that produces comprehensive administrative and accounting capabilities. This system is used to efficiently process license applications, issue frequency assignment, generate notices, generate invoices reports etc. Recently the Spectrum Division has decided, the NOC (No Objection Certificate) of radio equipments will not be issued without the required information inserting in the ASMS database system. The advantages of ASMS are describes as below:-

Helps user make new frequency assignments in a rational, orderly fashion.

• Manages licensed assignments.
• Enables compliance monitoring.
• Helps regulate radio equipment and radio personnel.
• Fully compliant with ITU SM-1370 and SM-1537 recommendations.
• Flexible system design includes functions ranging from national frequency allocations and assignment planning to license application processing, approvals, international coordination and accounting.
• The system can be readily adapted to meet specific requirements of national regulations and procedures.

In order to work effectively ASMS must possess large quantities of background information:

• Details of all frequency assignments, both new (proposed) and existing (licensed).
• Reference information, such as equipment specifications, band allocations, etc.

Examples of frequency assignment information can be:

• Link to administrative details of applicant
• Type of service involved
• Site location and characteristics
• Equipment characteristics 

Examples of reference information can be:

• NFAP (National Frequency Allocation Plan)
• Equipment technical specifications
• Fee constants, variables, algorithms
• City and province names
• Terrain data 

ASMS Data Migration Format

Please download the required format and submit to Spectrum Division of BTRC with all prescribed information (both hard copy and soft copy). It is mandatory to issue any NOC for radio equipments.

Click here to downdoal the ASMS Entry Form and Instruction.