The tremendous growth in wireless subscriber base coupled with increased use of data applications are making the decision makers at telcos realize the importance of investing in state-of-the-art T&M equipment. On the other hand, the emergence of 2.5G and 3G wireless networks meant to support high-speed data traffic offers new challenges. TRAI's recent paper found most of the telecom service providers wanting in the QoS parameters. It may be recalled that TRAI had set a timeframe 36 months for mobile operators and 48 months for fixed line operators which has got over and is planning to review QoS parameters.

Technology Trends
Software-based solutions gain Prominence: T&M equipment manufacturers are placing greater emphasis on software to make measurements easier to use, faster, and more accurate. Since these software-based testing equipment use PC-based platforms, the same hardware can be used to test any of the standards like GSM, GPRS or CDMA by simply changing the software. In other words, PC is most likely to become the standard T&M instrument hardware in the near future with the integration of software testing tools into it.

These solutions are easy to configure (according to user requirements), use and also come at a lower cost. More than that, for example, National Instruments promoted the concept of 'virtual instrumentation' allows users to design and configure their own instruments according to their requirements using software tools. On the other hand solutions like Agilent Technologies' new wireless application measurement software (WAMS), the central component of its data service assurance program, enables RF engineering teams to automate data traffic, quantify wireless data user experience and find the cause of problems through leading visualization and analysis tools, thereby reducing the cost of wireless data rollout.

WAMS enables RF engineers to build complex serial and parallel test sequences via an easy-to-use and customizable interface. Tests are independent of wireless technology and include multimedia message service (MMS), short message service (SMS), HTTP, FTP, e-mail, wireless-application protocol (WAP), and PING.

Portable T&M instruments: T&M companies are making handheld T&M devices with more functions and power. For examples, service providers can expect a growing number of portable analyzers that can meet the needs of burgeoning field applications. What is good about these instruments is that even though they are portable they are powerful and feature-packed. Also, many T&M equipment manufacturers are trying to harness the power and portability of handheld computers. For example, Noah Industries (Melbourne, FL) offers a fiber-optic power meter that ties into PDAs and provides graphs of the fiber's performance.

Realtime RF analyzers: Tektronix has come up with a new series of real-time spectrum analyzers that provides the ability to trigger, capture and analyze time-varying RF signals. RF signal characteristics are becoming more complex as RF communications increasingly replace wired technologies in applications ranging from inventory identification to video games. Today's RF signals carry complex modulation and change from one instant to the next, hopping frequencies, spiking briefly, and then disappearing. As a result, these RF signals are difficult to measure and present unpredictable behavior, making engineers' ability to observe RF devices with existing spectrum analyzers extremely challenging. This evolution in RF technology has spawned an unprecedented demand for a new approach to spectrum analysis. Realtime spectrum analysis has emerged as the vehicle to address this RF technology evolution.

• Digital technology is becoming all-pervasive. Whether it is communication systems, control systems, radar systems or any other, almost all the analog blocks are being replaced by digital. This is bringing profound changes in the area of test tools that are required. Signal Analyzers are required to have digital demodulation capability while the signal sources are required to create signals with digital modulation formats. Mixed Signal Oscilloscopes and Logic Analyzers have become a tool of choice for debugging digital designs.
  

• Whether digital or analog, the designs are moving to increasingly higher frequencies. In the digital domain, in order to accommodate higher data rates, the signal buses are changing to "serial" from the traditional "parallel" ones. This brings new and unforeseen challenges for design engineers and manufacturers. Signal integrity has become a critical factor for the success of digital designs and we see traditional microwave tools like Vector Network Analyzers as being used to decide the robustness of design of the physical layer.
  

• Induction of new technologies such as VoIP, MPLS, WLAN, UWB etc. demand suitable new design and validation tools.

Tips
Compliance with ITU and International Recommendations: For most T&M solutions, the specifications are laid out by the international bodies like ITU-T, ETSI and ANSI for accuracy and consistency. The buyer must ensure that the instrument complies with these standards. Since the specifications for the instrument are much tighter than the equipment or device to be tested, their compliance with the international body's recommendations is essential. If not, the results may lose accuracy and repeatability in the measurement

Portability and Ruggedness: The equipment should be easy to carry and should have easy and accessible connections. It should be rugged enough to support wide range of temperature, jerk and vibrations, and humidity conditions.

Technology support: The instrument should be such that it supports all the relevant technologies for testing. It means that if the instrument is designed for the transmission technology testing based on optical fiber then it should support the currently prevailing technology like SDH, POS and ATM on SDH together in one box. This allows the buyer for easy testing in the technology mixed environment and also allows the testing in the area of technology migration.

Application fitness: The instrument should not be so much general purpose to overkill the investment of the buyer. The instrument should target the correct market segment. For example, there are certain tests that are a must in field installation and maintenance and these are the key concern areas of the network operator. The instrument must be able to do all the tests needed by this segment, but need not include the entire lot of tests required in manufacturing and R&D. This will result in value for money for the buyer. Operators do not use R&D and manufacturing types of tests as they come in the area of factory acceptance test (FAT).

Scalability: The instrument should be such that it is able to scale to higher bandwidth, interface, and testing requirement. It should also be possible to upgrade the instrument without hardware and software limitations so that the investment remains protected in the evolving technology. For e.g., GPRS and 3G technologies are still in the growth stage and have not yet matured. Modifications are happening in these technologies and the instrument should be able to upgrade to the changing technology and protocols.

Pre- and after-sales support: The company should have a direct presence in India so that they can advise and optimize the testing and test times. There should be a strong technical support team in the T&M supplier company so that instant solutions can be found while troubleshooting.

Repair and uptime support: The T&M supplier should have a standard calibration, repair and support center so that support of the order of 24/7 can be obtained.

Solution level from company: The T&M company should have the core competence in the area of test and measurement and should not be a non-focus segment in the company. Also the company should be able to provide the test and measurement solution in all the segments right form R&D to operations. Such companies are able to offer the perfect fit for the T&M solution to the market.

Deployment trends
Next-generation SDH networks will be designed on MPLS technology platform. VoIP will become popular for voice communication. With the increasing demand on bandwidth from corporate and SOHO users, both access and long haul networks would be required to provide broadband capability. Service providers would increasingly depend on OSS/BSS systems in order to maintain higher QoS and grow their revenue and profit.

The complexity of test systems is driven and defined by the complexity of the product that is being tested. There is a rapid convergence of varied technologies into single products and thus there is an increasing onus being placed on the systems that test them. A perfect example is cellular phones. When one considers phones from a few years ago, voice was the primary application, whereas now it is just one among an array of features like camera, video, Bluetooth, WLAN, gaming, MP3 and video players to name a few.

We see that cellular phones have evolved from being just RF circuitry to being computing platforms. This means that the phone is a software enabled device, i.e. a device whose functionality is dictated primarily by the software that is present on it. And if we look around, we see more and more of such devices. New features are embedded at an amazing rate and as a result, the testing of such devices is increasingly challenging. Traditional based approaches fall well short of the mark when testing such devices. Adding a new vendor-defined box to test each new feature is ineffective, too cumbersome, and inflexible.

Often, there isn't a specific instrument built yet to test cutting edge functionality.

Looking at the example of a GPS device that are found in most modern cars, we can see the huge number of traditional instruments required to test such a device:

The disadvantages of such an approach are clearly visible. Also, any additional features that need to be tested leave no option but to add another device.

The virtual instrumentation approach offers a far more effective and efficient way to solve problems involving the testing of such devices. The only way to keep up with the changes in design of the devices under test is to employ a software oriented approach in the test system, and this is the governing principle behind Virtual Instrumentation.

A virtual instrumentation system is thus, a predominantly software-defined system, where software based on user requirements defines the functionality of generic, modular measurement hardware.

A similar testing application using the virtual Instrumentation approach can be visualized as seen below:

This approach to testing mirrors the software oriented model of the devices themselves, and this represents a significant trend in the test and measurement industry.

The way forward
The way forward is definitely to bring about user defined functionality test and measurement equipment, and this is one of the unique features of the virtual instrumentation approach.

It is imperative that the test instrument vendors keep pace with all these changes. In fact they have to always move ahead in close collaboration of the global OEMs/ NEMs so that they have the right tools available for validating the design of the next generation products.

From a hardware perspective, there should be a strong focus on driving the overall cost down by leveraging commercial technology in computing and semiconductor technology. From the software front, the way forward is to develop software that can abstract the system complexity of modern applications by providing a powerful yet productive means to test even the most complex and changing technology.

Testing systems based on the virtual instrumentation approach is clearly the path that the industry is taking. This type of a solution is acknowledged as the only way to effectively meet the emerging demands of modern test and measurement applications. Evidence of this is seen from the attitudes of leading manufacturers as well as consumers.

User issues
Convergence of RF & digital technologies is constantly challenging the users. They need to rapidly update cross-domain knowledge in order to survive and contribute in their work. Sometimes, users need to work on new technologies where standards are yet to be frozen. In this situation the right quality test tools may not be available.

Rapid changes in components, devices and hardware technology is reducing the life cycle of the test instruments. This means customers today need to upgrade sooner than earlier days.

From the user's perspective, if traditional instrumentation were used to solve such an application, there would be challenges like a very high number of devices with a large overall footprint, no inbuilt synchronization platform/bus to share data between different tests, as well as having to replicate hardware to test additional functions.

If virtual instrumentation is employed, users have to undergo familiarity with the approach and the tools involved.

Challenges
The multiplicity of new devices connecting to the wireline and wireless networks as well as the functionality that they possess is truly astounding. The greatest challenge faced by the T&M industry is to be able to keep pace and to effectively give customers ways to test these new devices and technologies.

To manage the cost of telecom networks, many service providers are becoming extremely sensitive to each and every cost input due to which sometimes quality of tools is getting compromised. This needs to be addressed immediately so that the network can continue to deliver quality service. As customers become more familiar with technology, they would become more demanding and the only way out for service providers is to improve QoS.

Shrinking life cycle of devices, components and hardware platforms challenge the test instrument vendors to provide longer support as preferred by customers.

Trends and Drivers
The spending on T&M as part of the network costs is dismally low in India. While globally, the cost of T&M equipment is 5-8 percent of the total network cost, in India, the figure is as low as 0.1 percent. Indications are that the T&M spend will go up in the coming years. More so because the new service providers are still in the rollout phase. Companies are still seeing T&M investment as expenditure. However, in future, they will see it as an investment as they will be required to differentiate on quality, better customer service, reliable networks and increased productivity.

Earlier, sanctions were a major hindrance in the growth and propagation of T&M. It must be remembered here that the major suppliers of T&M equipment are global vendors, primarily those from the US. And the easing of the US sanctions since October 2001 has enabled them to sell a much broader range of products.

Service providers bought spectrum analyzers, network analyzers, protocol analyzers, optical time domain reflectometers (OTDR), optical spectrum analyzers (OSA) and plesiochronous digital hierarchy and synchronous digital hierarchy (PDH/SDH) analyzers and handheld testers. BSNL and MTNL were the big customers and they will continue to remain too as they expand their network further. Private GSM and CDMA operators too are a huge market for these products as most of them are talking about improving quality of their network. Further, the thrust today is on teledensity. As a result, the emphasis will now be on quality of services. So the potential market for T&M equipment is likely to scale up. The signs are potent now. Before deregulation, T&M vendors were totally dependent on the government type of projects.

Primarily, the L1 business dominated the T&M equipment. It meant bulk purchase of hardware where vendors had no choice but to quote the lowest. Things have changed now after the entry of the private sector and corporatization of BSNL. There has been rationalization in procurement. Another noticeable trend is in solutions. Large vendors are pushing solutions rather than boxes.