Network Telemetry

Airtel 5G NSA Analysis & LTE Band Masking Technical Report

Research case study · by Shubhomoy (sgdev) · October 2026

⚖️ Legal, Fair Use & Research Disclaimer

This technical analysis is conducted strictly for independent RF engineering research, educational analysis, and telecommunications public policy study. All network logs are collected via standard client-side Android API diagnostics (NetMonster). No proprietary cellular firmware, network infrastructure, or confidential operational data was breached, reverse-engineered, or modified during this study. Compliance is maintained under global Fair Use principles.

1. Overview & Research Objective

This technical report evaluates the practical operation of Airtel's Non-Standalone (NSA) 5G architecture in urban environments. We specifically audit the radio bearer behavior, carrier aggregation dynamics, and how the network utilizes the LTE 1800 MHz (Band 3) anchor channel alongside the 3500 MHz (n78) 5G NR secondary cell.

2. Technical Background: 5G NSA vs. Anchor Dependency

In 3GPP Option 3x (Non-Standalone Architecture), the 5G New Radio (NR) execution relies entirely on an existing 4G LTE core network (EPC). The LTE channel acts as the primary control plane anchor for signaling, mobility management, and initial session setup, while the 5G NR cell acts as a secondary data pipe for user-plane throughput.

Because the status icon in consumer devices triggers based on cell broadcast signaling (SIB2/SIB13 or EN-DC availability flags), a "5G" status indicator often renders on user displays even when the active primary traffic routing is anchored on an oversubscribed 4G carrier.

3. Test Setup & Environment

Test Device: Android Handset (Snapdragon / Dimensity 5G Modems)
Diagnostic Tool: NetMonster v2.x (Android Network Telemetry API Listener)
Carrier: Bharti Airtel India (PLMN 404-45 / 405-XX)
Location & Time: Kasba / Ruby Region, Kolkata · October 2026

4. Radio Telemetry Capture

NetMonster screenshot showing Airtel LTE Band 3 anchor with 5G NSA 3500 — Fig. 1 — Client-Side NetMonster Capture: Airtel LTE Band 3 (1800 MHz) Primary Anchor paired with 5G NSA n78 (3500 MHz).

5. Technical Observations & Telemetry Breakdown

Analysis of the telemetry capture reveals the following radio parameters:

Anchor Carrier

LTE 1800 MHz (Band 3)
Bandwidth: 20 MHz
Role: EN-DC Control & Base Layer

Secondary 5G Cell

5G NSA 3500 MHz (n78)
Mode: Non-Standalone (Option 3x)
Role: Data Bearer Expansion

Primary LTE Anchor (Band 3): The radio interface maintains a 20 MHz channel on 1800 MHz (Band 3). This band provides necessary control signaling and broad coverage, serving as the EN-DC (E-UTRA-NR Dual Connectivity) master node.
5G NR Secondary Layer (n78): The 3500 MHz C-band allocation is attached as a secondary cell group (SCG). Due to high propagation loss at 3.5 GHz, indoor or edge-of-cell transitions force heavy reliance back onto the LTE 1800 MHz anchor layer.
User-Facing Signaling Behavior: When the 5G NR link degrades or enters power-saving sleep cycles, the device UI frequently maintains the 5G icon due to the persistent 4G anchor signaling, creating a perceived "always-on 5G" impression despite underlying 4G LTE throughput bounds.

6. Conclusion & Limitations

The captured telemetry confirms that Airtel’s 5G deployment effectively leverages LTE Band 3 (1800 MHz) as a robust anchor layer for 5G NSA connectivity. While this architecture accelerates 5G deployment without immediate standalone (SA) core replacement, real-world performance remains heavily bound to 4G anchor capacity and local C-band (n78) coverage density.

Note: This report reflects client-side RF diagnostics from a single localized sampling point. Radio metrics fluctuate dynamically based on cell load, distance to gNodeB/eNodeB, and physical signal attenuation.