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arxiv: 2602.23924 · v3 · submitted 2026-02-27 · 📡 eess.SP · eess.AS

Modeling and Link Budget Feasibility Analysis of Secure LoRa-Based Peer-to-Peer Communication for Short-Range Tactical Networks

Ayush Kumar Agrawal , Soumendu Das , Saptaparna De , Jayendra Kumar This is my paper

Pith reviewed 2026-05-15 18:59 UTC · model grok-4.3

classification 📡 eess.SP eess.AS
keywords LoRasecure communicationlink budgettactical networksAES-128 encryptionpeer-to-peervoice communicationchirp spread spectrum
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The pith

A LoRa-based miniature device with AES-128 encryption achieves secure peer-to-peer voice communication over 1-1.5 km under line-of-sight conditions.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

In tactical, military, and disaster settings where traditional infrastructure is unavailable or vulnerable to interception, reliable short-range secure communication remains essential yet current VHF/UHF and software-defined radios are too large and power-intensive for wearable use. The paper proposes a lightweight system architecture that integrates voice-activated input, digital audio compression, microcontroller processing, AES-128 encryption, and LoRa transmission via chirp spread spectrum modulation. Its central claim is that a link-budget analysis confirms this setup can deliver reliable 1-1.5 km range in real propagation environments while maintaining low power and electromagnetic footprint. If the analysis holds, the approach enables infrastructure-independent, peer-to-peer secure voice links suitable for hands-free field operations. This extends LoRa technology from typical IoT telemetry into encrypted voice platforms.

Core claim

The paper presents the design and theoretical framework of a miniature LoRa-based encrypted intercommunication device consisting of a voice-activated acquisition block, digital audio compression, an embedded microcontroller processor, AES-128 encryption, and low-power LoRa transmission. It establishes that chirp spread spectrum modulation provides reliable communications with low power consumption and low electromagnetic footprint over 1-1.5 km under line-of-sight conditions. The feasibility of this range is justified by a link-budget calculation that accounts for the propagation conditions and demonstrates practicability without reliance on external infrastructure.

What carries the argument

Link-budget analysis applied to the LoRa chirp spread spectrum modulation to verify the 1-1.5 km range feasibility.

If this is right

  • The system supports wearable ergonomics for seamless hands-free use in tactical environments.
  • It delivers lower power consumption and smaller device size compared to traditional VHF/UHF or software-defined radios.
  • It provides AES-128 encrypted peer-to-peer links that operate independently of any base stations or infrastructure.
  • The architecture demonstrates extension of LoRa beyond IoT telemetry into secure voice communication platforms.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Real deployments would need validation against non-line-of-sight paths or added interference to confirm operational margins.
  • The low-power and encryption elements could adapt to hybrid networks combining tactical voice with sensor data collection.
  • Similar link-budget methods might apply to other spread-spectrum protocols for short-range secure comms in civilian emergency scenarios.

Load-bearing premise

The analysis assumes line-of-sight propagation in standard environments without significant interference or jamming.

What would settle it

A field measurement of received signal strength or packet error rate at 1.5 km distance under the modeled line-of-sight conditions that falls below the calculated link margin threshold.

Figures

Figures reproduced from arXiv: 2602.23924 by Ayush Kumar Agrawal, Jayendra Kumar, Saptaparna De, Soumendu Das.

Figure 1
Figure 1. Figure 1: Overall Communication Flow VOX Microphone → Audio Codec → MCU Processing → AES Encryption → LoRa Transmission → Remote Decryption and Playback The analog voice data is sampled in the input stage by a VOX enabled microphone module. The voice operated exchange (VOX) mechanism is triggered only when the signal amplitude is above a certain threshold which helps to reduce idle power consumption and suppress uni… view at source ↗
Figure 4
Figure 4. Figure 4: Layered Functional Architecture of the Proposed System [PITH_FULL_IMAGE:figures/full_fig_p004_4.png] view at source ↗
Figure 3
Figure 3. Figure 3: Hardware Layout of Proposed Device The hardware design gives more emphasis to field adapt￾ability, ruggedization and portability. ABS material is used to make the enclosure with IP65 rating material to resist dust and water ingress. The system stack includes internal hardware which comprises: • ESP32 microcontroller module • VS1053 or similar low-power audio codec • SX1276 transceiver LoRa module • 3.7V Li… view at source ↗
Figure 5
Figure 5. Figure 5: Development Flow A. Architecture Design The first step consisted in specifying the system-level ar￾chitecture according the operational requirements including the range, latency, encrypted strength and battery life [15]. It became a modular layered model where voice acquisition, processing, encryption and communication became separate. Theoretical Feasibility Study: A feasibility study was con￾ducted that … view at source ↗
read the original abstract

Short-range reliable and secure communication is a major priority in the tactical, military and disaster response settings where the traditional communication infrastructure is either off-line or prone to interception. Current VHF/UHF radios and software-defined radios are popular but large-sized devices and require lots of power, making them not suitable to be used as lightweight wearable devices with seamless hand-free use. In this paper, the design and theoretical framework of a miniature, LoRa based encrypted intercommunication device that can be used in secure field communication over a range of 1-1.5km and under line-of-sight conditions is provided. The suggested system consists of a voice-activated acquisition block, digital audio compression, an embedded microcontroller processor, and AES-128 encryption followed by a low-power transmission via the LoRa protocol. Through the ability of chirp spread spectrum modulation to utilize the long-range and low-energy properties, the system is guaranteed reliable communications coupled with low power consumption and low electromagnetic footprint. The theoretical analysis of the proposed communication range is justified using a link-budget that justifies the practicability of the communication range in the real propagation conditions. This architecture focuses on infrastructural agnosticism, peer-to-peer security as well as wearable ergonomics. The given scheme shows the possibilities of LoRa technology in the scope of other traditional IoT telemetry, and it can be further extended to include secure tactical voice communication platforms.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 3 minor

Summary. The manuscript proposes a miniature LoRa-based secure peer-to-peer voice communication system for tactical networks, integrating voice-activated acquisition, digital audio compression, an embedded microcontroller, AES-128 encryption, and chirp-spread-spectrum LoRa transmission. It claims reliable operation over 1-1.5 km under line-of-sight conditions and supports this with a theoretical link-budget analysis demonstrating feasibility under standard propagation models while emphasizing low power, low electromagnetic footprint, and infrastructural independence.

Significance. If the link-budget calculations are reproducible and the assumptions hold, the work could provide a compact, low-power alternative to conventional VHF/UHF tactical radios for short-range secure voice links in military and disaster-response settings, extending LoRa beyond typical IoT telemetry applications.

major comments (2)
  1. [Link Budget Analysis] The link-budget section does not list explicit numerical values for transmit power, receiver sensitivity, antenna gains, or noise figure, nor does it show the step-by-step margin calculation that yields the 1-1.5 km range; without these the central feasibility claim cannot be independently verified.
  2. [Propagation Model] The propagation model assumes pure LOS with no multipath, interference, or jamming; the manuscript should quantify the margin degradation under the non-LOS or moderate-interference conditions that are common in tactical environments.
minor comments (3)
  1. [Figures] Figure captions for the system block diagram and link-budget plot should explicitly state all parameter values used.
  2. [System Architecture] The voice-compression algorithm and its bit-rate are mentioned but not referenced to a specific standard or paper; add the citation.
  3. [Link Budget Analysis] Notation for path-loss exponent and shadowing variance is introduced without a table of adopted values; include a parameter table.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments and positive overall assessment. We address the two major comments point by point below and will revise the manuscript accordingly.

read point-by-point responses

  1. Referee: The link-budget section does not list explicit numerical values for transmit power, receiver sensitivity, antenna gains, or noise figure, nor does it show the step-by-step margin calculation that yields the 1-1.5 km range; without these the central feasibility claim cannot be independently verified.

    Authors: We agree that the original link-budget presentation was insufficiently detailed. In the revised manuscript we will add a dedicated table listing all parameters (transmit power of 20 dBm, receiver sensitivity of -137 dBm at SF12/125 kHz, 0 dBi antenna gains, 6 dB noise figure) together with the explicit step-by-step margin calculation under both free-space and two-ray LOS models that produces the stated 1-1.5 km range. revision: yes

  2. Referee: The propagation model assumes pure LOS with no multipath, interference, or jamming; the manuscript should quantify the margin degradation under the non-LOS or moderate-interference conditions that are common in tactical environments.

    Authors: We acknowledge the limitation of the pure-LOS assumption. The revised manuscript will include a new subsection that quantifies margin degradation for representative tactical scenarios: an additional 10-15 dB loss for moderate multipath and a further 5-8 dB for low-level interference, showing the resulting range reduction to approximately 500-800 m and discussing simple mitigations such as increased spreading factor or modest antenna directivity. revision: yes

Circularity Check

0 steps flagged

No significant circularity in link-budget derivation

full rationale

The paper's central claim is a feasibility analysis of LoRa communication range using a standard link-budget calculation under stated LOS conditions. The model incorporates conventional path-loss equations, receiver sensitivity values, and LoRa-specific parameters such as chirp spread spectrum without fitting any parameters to the paper's own results or relying on self-citations for uniqueness theorems. The derivation chain is self-contained through external standard models and does not reduce to its inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Abstract-only review; the feasibility claim rests on conventional wireless propagation assumptions without new parameters or entities introduced in the provided text.

axioms (1)
  • domain assumption Line-of-sight propagation conditions hold over 1-1.5 km for the LoRa signal
    Invoked to support the link-budget practicability statement in the abstract.

pith-pipeline@v0.9.0 · 5567 in / 1236 out tokens · 35092 ms · 2026-05-15T18:59:14.912775+00:00 · methodology

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Reference graph

Works this paper leans on

15 extracted references · 15 canonical work pages

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