# System-Level Evaluation of Uplink Access Schemes for Ambient IoT

DevFeed: [System-Level Evaluation of Uplink Access Schemes for Ambient IoT](<https://devfeed.tech/articles/system-level-evaluation-of-uplink-access-schemes-for-ambient-iot-97338.md>)

Original publisher: [Read original article](<https://arxiv.org/abs/2610.30856>)

Author: Douglas Dziedzorm Agbeve, Henrique Duarte Moura, Andrey Belogaev, Jeroen Famaey

Published: 2026-10-23T04:00:00Z

Content type: article

Language: en

Sources: [arXiv: Networking](<https://devfeed.tech/sources/arxiv-networking.md>)

Topics: [Internet of things](<https://devfeed.tech/topics/iot.md>), [Internet](<https://devfeed.tech/topics/internet.md>)

Tags: [ambient](<https://devfeed.tech/tags/ambient.md>), [cs-ni](<https://devfeed.tech/tags/cs-ni.md>), [delay](<https://devfeed.tech/tags/delay.md>), [energy](<https://devfeed.tech/tags/energy.md>), [energy-harvesting](<https://devfeed.tech/tags/energy-harvesting.md>), [energy-storage](<https://devfeed.tech/tags/energy-storage.md>), [evaluation](<https://devfeed.tech/tags/evaluation.md>), [hybrid](<https://devfeed.tech/tags/hybrid.md>), [iot](<https://devfeed.tech/tags/iot.md>), [scheduling](<https://devfeed.tech/tags/scheduling.md>), [scheme](<https://devfeed.tech/tags/scheme.md>), [system](<https://devfeed.tech/tags/system.md>), [trade](<https://devfeed.tech/tags/trade.md>)

## AI overview

Using NB-IoT as an implementable reference for Ambient IoT uplink access, the study models solar harvesting, supercapacitor storage, and hysteretic brown-out in the LENA-NB ns-3 module. It compares contention-based Random Access (RA), Scheduling Request (SR), proposed Hybrid Scheduling Request (HSR), and Idealized Fast Uplink Grant (FUG) as a performance bound. HSR combines reserved request occasions with opportunistic contention. Relative to RA, HSR reduces mean packet delay by up to 69%, while SR reduces energy per delivered bit by up to 24%. The abstract presents these as distinct benefits and does not give further conditions or results.

## Source excerpt

arXiv:2610.30856v1 Announce Type: new Abstract: Ambient Internet of Things (A-IoT) devices operate under stringent energy constraints, relying on harvested power in the $\mu$W-to-mW range and limited energy storage. The A-IoT air interface for active devices is still under development; we therefore use Narrowband Internet of Things (NB-IoT) as an implementable reference for evaluating autonomous Uplink (UL) access under harvested energy. Under these conditions, the standard NB-IoT contention-based Random Access (RA) procedure incurs substantial per-packet overhead, making UL access in dense A-IoT networks increasingly energy-expensive. Context-retaining UL access schemes reduce this overhead, but their energy-latency trade-offs are insufficiently studied in literature under realistic harvesting and protocol constraints. To address this gap, we extend the LENA-NB ns-3 module with solar energy harvesting, supercapacitor storage, and a hysteretic brown-out mechanism, and propose Hybrid Scheduling Request (HSR), a hybrid UL access scheme combining reserved request occasions with opportunistic contention. We compare RA, Scheduling Request (SR), HSR and an Idealized Fast Uplink Grant (FUG) serving as a performance bound. Results show that HSR reduces mean packet delay by up to 69% and SR reduces energy per delivered bit by up to 24%, both relative to RA.