Змест

EARFCN

EARFCN Стаіць за E-UTRA Absolute Radio Frequency Channel Number. It’s a standardized identifier used in LTE (Long-Term Evolution) і LTE-Advanced cellular networks to uniquely specify the center frequency of a radio channel. Instead of dealing with raw frequencies (напр., 2140 МГц), network engineers and equipment use EARFCN values for simplicity and consistency.

EARFCN provides a consistent way to reference LTE carrier frequencies globally. FDD (Частата): Separate EARFCN for UL and DL. TDD (Час дывізіёна дуплекс): Single EARFCN (UL/DL share frequency).

RSRP

RSRP (Reference Signal Received Power) is a critical measurement in LTE (Long-Term Evolution) і 5G-NR (New Radio) networks that quantifies the сіла сігналу from a cell tower (eNodeB/gNodeB) at your device (UE). It’s essential for network performance, handover decisions, і карыстацкі досвед.

RSRP measures: The average power (ў дБм) received from a single cell-specific reference signal (CRS) over a specific bandwidth (typically one resource block ≈ 180 кГц). Focuses толькі on reference signals—not the entire channel noise or interference.

Typical RSRP Values:

RSRP (дБм)	Якасць сігналу
> -80 дБм	Выдатны (моцны)
-80 у -90 дБм	добра
-90 у -100 дБм	Fair (usable)
< -100 дБм	бедных (weak/unstable)
< -120 дБм	Няма сігналу

SNR

SNR (Суадносіны сігнал/шум) measures the strength of a desired signal relative to background noise. It quantifies how clearly a signal can be distinguished from interference in communication systems (Wi-Fi, клеткавы, аўдыё, і г.д.). SNR is critical for performance—higher SNR means clearer data transmission, fewer errors, and faster speeds.

Дыяпазон SNR	Performance Impact
> 30 дэцыбел	Flawless 4K streaming, low-latency gaming.
20–30 дБ	Smooth HD video, fast browsing.
10–20 dB	Basic web browsing; occasional buffering.
0–10 дБ	Unstable connectivity; frequent drops.
< 0 дэцыбел	Connection lost (noise overwhelms signal).

SNR vs. Related Metrics:

Метрыка	фокус	SNR Comparison
RSRP	Raw signal strength (LTE/5G).	SNR depends on RSRP—but subtracts noise.
RSSI	Total received power (сігнал + шум).	SNR = (RSSI – Шум) / Шум.
Сінр	Signal vs. шум + перашкоды (more precise).	Often used interchangeably with SNR.

QOS

Explanation of common terms in Vcan2024 QOS

QoO (Якасць абслугоўвання) is a set of technologies and policies used in networking to prioritize traffic, manage bandwidth, і ensure reliable performance for specific applications, карыстальнікаў, or services. It’s critical for maintaining consistent user experiences, especially in networks with limited resources (напр., клеткавы, enterprise, or IoT networks).

Key Goals of QoS:

Прыярытэтызацыя: Treat high-importance traffic (напр., відэазванкі, аварыйныя службы) як “VIP” over low-priority traffic (напр., file downloads).
Resource Allocation: Reserve bandwidth for critical tasks.
Minimize Latency/Jitter: Keep delays low for real-time apps (Віп, гульнявой).
Reduce Packet Loss: Ensure data isn’t dropped during congestion.

RSSI

RSSI (Індыкатар магутнасці атрыманага сігналу) is a measurement of the total received power (сігнал + шум + перашкоды) in a wireless communication system. It’s a fundamental metric used across Wi-Fi, клеткавы (LTE/5G), Bluetooth, and IoT networks to gauge raw signal strength—but it does not distinguish between useful signals and noise.

Як правіла negative values (since dBm is referenced to 1 міліват):

-30 дБм: Extremely strong (near transmitter).
-70 дБм: Умераны (reliable connectivity).
<-90 дБм: Слабы (unstable or unusable).

Comuart

COMUART адносіцца да а УАПП (Універсальны асінхронны прыёмнік/перадатчык) interface used for паслядоўная сувязь, typically found in embedded systems, networking hardware, or industrial devices. The “COM” prefix often denotes its role in communication ports (напр., РС-232, TTL серыйны).