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It has been 25 years since the 900 MHz GSM standard launched digital wireless communications. The appetite for mobile data continues to grow relentlessly, and the drive for further technological advancement shows no sign of slowing. Analysts forecast a tenfold increase in mobile data traffic over the next six years, and the number of connected devices—the Internet of Things (IoT)—is expected to rise exponentially. With both subscriber counts and per‑user data consumption climbing, mobile network operators must ensure a consistently excellent quality of experience for years to come.
2G/3G/4G technologies and future improvements
Today’s leading LTE‑Advanced products can reach up to 600 Mbit/s under ideal lab conditions. In live networks, propagation effects and shared channel operation reduce achievable speeds because available bandwidth is distributed among active users. Still, LTE and LTE‑Advanced have substantially increased data rates and network capacity. Several technical advances account for this improvement:
- A wide system bandwidth of 20 MHz available to individual users, with the ability to combine up to five 20 MHz carriers via carrier aggregation (CA).
- Spatial multiplexing through MIMO (multiple-input, multiple-output) using between two and eight/four transmit/receive antennas.
- Fast OFDMA multiplexing that allows frequency and time resources to be reallocated on the order of milliseconds.
- High‑order modulation schemes such as QPSK, 16QAM, 64QAM and 256QAM, which increase spectral efficiency.
Meeting demands by measuring against standards
The adoption of LTE and LTE‑Advanced has enabled operators to handle growing traffic and service expectations. Many enhancements stem from 3GPP standardization and bring practical benefits:
Enhanced Multimedia Broadcast Multicast Service (eMBMS) provides an efficient way to deliver identical content—such as mobile TV—to many users simultaneously, or to distribute software updates without establishing individual unicast connections to each device.
3GPP specifications also define modes that let devices use multiple access technologies in tandem. For example, a smartphone can send email via WLAN while streaming video over LTE. Carrier aggregation into unlicensed bands can boost capacity, and IP‑layer combination of LTE in licensed spectrum with WLAN in unlicensed spectrum is possible to increase throughput and resilience.
RF and protocol testing systems help network operators select suitable wireless device providers. The test solutions ensure that the devices comply with mobile network standards. Picture credit: Rohde & Schwarz
In dense, heterogeneous deployments—such as pedestrian zones—coordinated multipoint transmission and reception (CoMP) enables base stations to cooperate when sending signals to a device. Coordinated use of MIMO and joint baseband precoding improves coverage and performance at cell edges.
Device‑to‑device (D2D) features introduce two important capabilities. First, network‑assisted discovery lets nearby devices detect each other. Second, those devices can exchange data directly without relaying through the serving base station, either as local broadcasts to interested users or as point‑to‑point links. Public safety applications already use the latter; over time D2D could extend to automotive use cases such as vehicle‑to‑vehicle communication and functions that support autonomous driving.
Although LTE/LTE‑A steadily improves performance, full 4G coverage will take time. Smooth handover to 2G and 3G remains important. In many situations 2G/3G data rates suffice, and simpler technologies can provide cost‑effective solutions with long battery life—GPRS modules are still common in many machine‑to‑machine (M2M) applications.
The high performance of LTE/LTE‑A, its interoperability with legacy networks and the complementary use of WLAN allow operators to address growing big‑data needs. Broadcast and multicast options add flexibility for mass delivery of identical content.
LTE standards have already introduced improvements tailored to M2M. For example, LTE Category 0 reduces complexity for low‑data‑rate devices by omitting features such as MIMO. Mechanisms to prevent signaling overload when large numbers of M2M devices simultaneously access the network have been added. Subsequent enhancements reduce bandwidth down to 180 kHz with limited mobility, effectively creating an M2M‑optimized radio access technology that borrows LTE procedures only as needed for these specific use cases.
Cost‑efficient mobile T&M equipment is used to install a base station. Picture credit: Rohde & Schwarz
The anticipated growth of IoT and industry‑specific requirements—from automotive and healthcare to robotics—will drive further significant enhancements. Researchers and vendors are already exploring 5G and beyond. Instrument manufacturers and test houses are contributing to standards work and prototype evaluation to ensure future networks meet performance and reliability goals.
How does T&M equipment contribute?
Test and measurement (T&M) equipment is central both to developing new technologies and to operating reliable networks. A wide range of test solutions is required to design and manufacture devices, RF components, base stations and core network elements, and to validate performance during deployment.
Network operators rely on signal generators, signal and spectrum analyzers and other instruments to qualify infrastructure products and select those that meet their performance criteria. Many operators specify additional tests based on unique network requirements. Integrated testers—such as the R&S® CMW500 wideband radio communication tester—can emulate network functions to verify device behavior, measure data rate performance and check transmitter power and protocol compliance.
During field installation, compact testers let engineers verify regulatory compliance quickly. After deployment, operators tune parameters—such as handover thresholds—and identify coverage gaps to optimize network performance and improve customer experience. Measurement apps like QualiPoc from SwissQual run on commercial smartphones to collect drive‑test and crowd‑sourced QoE data, enabling operators to assess the end‑user perspective.
Network operators use T&M equipment to analyse network performance and optimize the end user experience. Picture credit: Rohde & Schwarz
In the core network, packet‑level analysis is increasingly important for classifying traffic and steering services through optimal paths. IP analysis tools provide this visibility. The same capabilities are valuable in device testing: integrated on platform testers, they reveal which background applications generate persistent IP streams and how these affect signaling and battery life.
Unpredictable interference can also degrade service. Fixed network monitoring and portable interference‑hunting tools help operators locate and eliminate sources—such as defective neon signs—that can produce spurious emissions within base station receive bands and disrupt user traffic.
T&M instruments are already essential for defining the next generation of standards. Signal generators and analyzers evaluate candidate 5G components; flexible test platforms support wide frequency ranges, varying bandwidths and diverse transmission schemes. They are indispensable for measuring propagation in new frequency bands, for multiport network analysis of advanced antenna systems, and for over‑the‑air testing as connectors become impractical at centimeter and millimeter wavelengths. Equally important is the ability to measure application‑level impacts on throughput, signaling load and power consumption—crucial for IoT modules where per‑application behavior on the IP layer must be quantified.
Across device development, infrastructure deployment and ongoing network operations, test and measurement capabilities continue to evolve to ensure that both technology and user experience standards are maintained.