The rapid growth of mobile broadband traffic has increased the demand for higher spectral efficiency and enhanced user throughput in cellular networks. Carrier Aggregation (CA), introduced in 3GPP Release 10 as part of LTE-Advanced, enables simultaneous use of multiple component carriers to expand the effective bandwidth without requiring contiguous spectrum. While CA increases the available bandwidth in principle, the achievable throughput in operational networks depends strongly on radio quality and scheduler behavior. This thesis presents an empirical evaluation of Carrier Aggregation in commercial LTE networks deployed in Milano, Italy. Measurements were conducted across three mobile operators using multiple Qualcomm chipset-based user equipment devices under stationary (standalone) and mobility (dynamic) scenarios. Modem logs were extracted from the devices, decoded using Qualcomm QCAT, exported in text format, and processed using MATLAB to generate synchronized time-series of CA depth, downlink throughput, and radio KPIs (RSRP, RSRQ, and SNR). A transition-based methodology was applied to detect real-time CA depth changes (e.g., 3CC → 4CC and 4CC → 3CC) and to compare throughput immediately before and after each transition. Results confirm that CA behavior is highly dynamic and operator-dependent, with aggregation depth ranging from low-order configurations to advanced multi-carrier operation under favorable conditions. In standalone tests, carrier activation typically increased throughput, and the highest post-transition throughput values were observed under stable conditions. In dynamic tests, Operator2 exhibited the strongest average throughput increase during CC activation events, indicating more effective utilization of additional carriers under mobility. Carrier release events generally reduced throughput, with the magnitude of degradation depending on instantaneous radio quality, particularly SNR. Overall, the study demonstrates that throughput does not scale linearly with the number of aggregated carriers. Aggregation depth reflects network capability and spectrum availability, but effective performance is governed by spectral efficiency, radio conditions, and MAC-layer resource allocation. The proposed transition-based analysis framework provides a practical approach for evaluating Carrier Aggregation behavior using real UE logs and supports deeper understanding of multi-carrier strategies in modern LTE networks.
La crescita del traffico mobile a banda larga ha reso necessario migliorare l’efficienza spettrale e la capacità delle reti cellulari. Il Carrier Aggregation (CA), introdotto nel 3GPP Release 10 come parte di LTE-Advanced, consente l’utilizzo simultaneo di più component carrier per aumentare la larghezza di banda effettiva senza richiedere spettro contiguo. Sebbene il CA incrementi teoricamente la banda disponibile, il throughput reale dipende dalla qualità radio e dai meccanismi di scheduling. Questa tesi presenta un’analisi sperimentale del comportamento del Carrier Aggregation in reti LTE commerciali operative a Milano. Le misurazioni sono state effettuate su tre operatori mobili utilizzando dispositivi user equipment basati su chipset Qualcomm, in condizioni stazionarie e dinamiche. I log modem sono stati estratti dai dispositivi, decodificati tramite Qualcomm QCAT ed elaborati in MATLAB per ottenere serie temporali sincronizzate di profondità di aggregazione, throughput in downlink e indicatori radio (RSRP, RSRQ, SNR). È stata applicata una metodologia basata sull’analisi delle transizioni temporali per identificare variazioni nella profondità di aggregazione (ad esempio 3CC → 4CC) e confrontare il throughput prima e dopo ciascun evento. I risultati mostrano che la profondità di aggregazione varia tra gli operatori e tra scenari stazionari e dinamici. Nei test stazionari, l’attivazione di carrier aggiuntivi ha generalmente prodotto un aumento del throughput. Nei test dinamici, l’Operatore2 ha evidenziato l’incremento medio più significativo durante le transizioni di aumento dei carrier, indicando un utilizzo più efficiente delle risorse aggregate in mobilità. Le riduzioni del numero di carrier sono risultate associate a cali di throughput, fortemente influenzati dalla qualità istantanea del segnale. L’analisi conferma che il throughput non cresce linearmente con il numero di carrier aggregati. La profondità di aggregazione rappresenta la capacità potenziale della rete, mentre le prestazioni effettive dipendono principalmente dall’efficienza spettrale, dalla qualità radio e dall’allocazione delle risorse a livello MAC. Il lavoro fornisce un approccio pratico per valutare il comportamento del Carrier Aggregation in reti LTE commerciali basato su log reali dei dispositivi.
Carrier aggregation techniques in mobile network
Shaik, Jalaluddin
2024/2025
Abstract
The rapid growth of mobile broadband traffic has increased the demand for higher spectral efficiency and enhanced user throughput in cellular networks. Carrier Aggregation (CA), introduced in 3GPP Release 10 as part of LTE-Advanced, enables simultaneous use of multiple component carriers to expand the effective bandwidth without requiring contiguous spectrum. While CA increases the available bandwidth in principle, the achievable throughput in operational networks depends strongly on radio quality and scheduler behavior. This thesis presents an empirical evaluation of Carrier Aggregation in commercial LTE networks deployed in Milano, Italy. Measurements were conducted across three mobile operators using multiple Qualcomm chipset-based user equipment devices under stationary (standalone) and mobility (dynamic) scenarios. Modem logs were extracted from the devices, decoded using Qualcomm QCAT, exported in text format, and processed using MATLAB to generate synchronized time-series of CA depth, downlink throughput, and radio KPIs (RSRP, RSRQ, and SNR). A transition-based methodology was applied to detect real-time CA depth changes (e.g., 3CC → 4CC and 4CC → 3CC) and to compare throughput immediately before and after each transition. Results confirm that CA behavior is highly dynamic and operator-dependent, with aggregation depth ranging from low-order configurations to advanced multi-carrier operation under favorable conditions. In standalone tests, carrier activation typically increased throughput, and the highest post-transition throughput values were observed under stable conditions. In dynamic tests, Operator2 exhibited the strongest average throughput increase during CC activation events, indicating more effective utilization of additional carriers under mobility. Carrier release events generally reduced throughput, with the magnitude of degradation depending on instantaneous radio quality, particularly SNR. Overall, the study demonstrates that throughput does not scale linearly with the number of aggregated carriers. Aggregation depth reflects network capability and spectrum availability, but effective performance is governed by spectral efficiency, radio conditions, and MAC-layer resource allocation. The proposed transition-based analysis framework provides a practical approach for evaluating Carrier Aggregation behavior using real UE logs and supports deeper understanding of multi-carrier strategies in modern LTE networks.| File | Dimensione | Formato | |
|---|---|---|---|
|
Carrier_Aggregation_Techniques_in_Mobile_Networks.pdf
non accessibile
Descrizione: This thesis presents an experimental evaluation of Carrier Aggregation (CA) in commercial LTE-Advanced networks deployed in Milano, Italy. Using Qualcomm-based user equipment, modem logs were exported via QCAT and processed with custom MATLAB scripts to analyze aggregation depth, throughput behavior, and radio quality indicators under both stationary and mobility scenarios. A transition-based methodology was developed to correlate real-time changes in component carrier count with instantaneous throughput variation. The results demonstrate that although higher aggregation depth increases theoretical bandwidth, effective throughput depends primarily on spectral efficiency, signal-to-noise ratio, and scheduling efficiency. Among the evaluated operators, stronger dynamic performance scaling was observed under mobility conditions, highlighting the importance of radio quality stability rather than carrier count alone.
Dimensione
7.53 MB
Formato
Adobe PDF
|
7.53 MB | Adobe PDF | Visualizza/Apri |
I documenti in POLITesi sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/10589/252706