THROUGHPUT IN 5G: BETWEEN THEORY AND REALITY – BEYOND THE 3GPP SPECS
In 5G conferences and white papers, it’s common to read about throughput figures reaching 10 Gbps or higher. These numbers often come directly from 3GPP specifications, presented as the “peak data rates” possible under the standard. However, for most people, running a speed test on their smartphone produces results that are far from those impressive figures. This gap between expectation and reality is not a flaw in the technology—it’s a misunderstanding of what those numbers truly represent.
3GPP defines throughput under idealized conditions: wide contiguous spectrum (e.g., 100 MHz in FR1 or 400 MHz in FR2), the highest modulation order (256QAM or beyond), maximum number of MIMO layers (up to 8 or more), perfect radio conditions (high SINR, no interference), and a single user occupying all resources.
But in real-world deployments, networks operate in a far more complex environment. Throughput is impacted by:
- Spectrum fragmentation – Operators rarely have 100 MHz or more in a single block, especially in sub-6 GHz bands.
- Interference and SINR – Neighboring cells, environmental clutter, and indoor penetration reduce achievable modulation and coding schemes.
- Network load – Resources are shared among dozens or hundreds of users, limiting the fraction of spectrum allocated per user.
- Mobility – Handover procedures, Doppler shifts, and changing channel conditions impact throughput stability.
- Device diversity – Not all devices support the same number of antennas, carrier aggregation bands, or advanced features.
- Backhaul constraints – Even if the air interface allows gigabit speeds, transport limitations can throttle performance.
This is why real user throughput is often a fraction of theoretical peak throughput. And yet, for operators, the true measure of success is not achieving a lab benchmark once, but delivering consistent, reliable, and predictable user experience across the network.
We must set the right expectations with business stakeholders, regulators, and end-users, emphasizing quality of experience (QoE) rather than theoretical maximums.
Perhaps the most important shift in perspective is this: instead of asking “What is the maximum throughput the standard supports?”, the more relevant question is “What is the sustainable throughput that users can realistically experience, consistently, across different scenarios?”.
That answer is where the real value of 5G - and the work of those optimizing it - truly lies.
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