Monojit Samaddar, Country Director, VIAVI Solutions, India

Monojit Samaddar, Country Director, VIAVI Solutions, India

Modern digital land mobile radio (LMR) and software defined radio (SDR) technologies have significantly improved security, range and spectral efficiency. Radio test solutions have followed suit, incorporating advanc­ed au­to­mation, signal mapping and spectrum analysis features for the lab and field.

Land mobile radio

LMRs are two-way communication de­vices used for person-to-person voice and data transmission in many important government and commercial applications, providing essential voice and data communication for diverse users around the glo­be. As technology has progressed over the years, LMR devices are incorporating more advanced digital technologies that utilise computer-controlled access for efficient allocation of channels to subscribers.

Radio products and standards have ev­olved to have improved range, reliability, and spectrum utilisation. Simultane­ously, LMR test, measurement and mapping solutions have consolidated advanced ca­pa­bilities into integrated, compact equipment suitable for multiple use cases, events and environments.

LMR testing

The range, security and reliability of LMR systems provide made them a logical fit for critical communications. In light of  unpredictable field conditions and security threats, LMR radios must remain robust while maintaining high performan­ce standards of transmit power, error rate, and sensitivity. Over-the-air LMR ra­dio testing aids deployment activities and helps in detecting equipment failures. Portability has become an invaluable asset for radio test equipment that often allows LMR subscribers to prepare for challenging environments.

With a high degree of market diversity, exacting test requirements and lofty reliability expectations, LMR testing can quickly become a complicated and challenging undertaking. Signal generators, spectrum analysers, power meters, frequency counters, computers and sensors must be interconnected and configured appropriately to constitute an accurate and repeatable communications test. This can become a long and arduous process, prone to hardware com­patibility issues, set-up errors, operat­or-to-operator variation and inordinate test and reporting times. Technical resource constraints can further worsen these challenges as electronics industry expansion co­n­tinues to place an unprecedented strain on the radio frequency talent pool.

Today, the availability of a wide range of versatile, easy-to-use and portable ra­d­io test solutions allow development, tes­ting and maintenance of LMR equipment of all leading original equipment manufacturers (OEMs).

Software defined radio systems

Software has become the largest component of electronic systems today, de­manding more development resources. There is a need for a paradigm shift in the software development processes to enable greater design flexibility, speed up implementation of latest innovations, extend the lifetime of products and reduce overall life cycle costs. Techno­lo­gy advancements have significantly changed the way radios are built, to the point where it is no longer just hardware that modulates and demodulates waveforms. The software defined radio pa­ra­digm is on the leading edge of radio technology, using software to implement most of the radio functionalities, including the modulation and demo­d­ulation of waveforms. eCoSuite provi­d­es the ideal integrated developme­nt environment for implementing software co­m­municati­o­ns architecture (SCA) in heterogeneous embedded distributed systems.

SDR technology uses software, instead of conventional hardware, to perform ra­dio signal processing functions. Filters, error correction, synchronisers, modulato­rs/demodulators, and frequency tuners used in conventional systems can all be wr­i­tten in software. Software defined devices need to be quickly reconfigured to adapt to changing product requirements. SDRs use high speed reprogrammable devices such as digital signal processors, field programmable grid array and general-purpose processors to execute tasks performed by hardware in conventional radio systems.

SDR testing

The flexibility provided by SCA makes the technology a logical choice to meet the ever-changing requirements of today’s commercial and military SDR products. As SDRs are being more widely deployed, test and measurement instruments are ramping up to be able to test SDRs in a way that was not possible before. For ex­ample, OEMs of SCA tactical radios re­quire a platform that is modular, scalable and traceable.

In many cases, the products and protocols under testing are evolving or still being defined in the product development life cycle. Supporting all the changes in hardware is very expensive and time-consuming. In fact, some traditional testers may even be obsolete by the time they are brought to market. Software-defined, or vi­rtual, testing instruments provide the level of flexibility required to adjust as st­an­dards and protocols evolve.

Working together

Combining the functionality and precision of disparate radio test equipment into a singular package no longer requires an oversized form factor or unlimited budget. Test solutions required to support this ra­pid advancement have kept pace with un­­precedented test feature diversity as well as the need for automation.