5G & LTE Technical Glossary
Core Identifiers
gNB
(Next-generation NodeB)
The 5G base station that communicates wirelessly with the mobile device. It is the 5G successor to the 4G eNB.
The 5G base station that communicates wirelessly with the mobile device. It is the 5G successor to the 4G eNB.
CID
(Cell Identifier)
A unique number assigned to a specific cell sector within a gNB. Combined, the gNB:CID provides the exact identity of the transmitter you are connected to.
A unique number assigned to a specific cell sector within a gNB. Combined, the gNB:CID provides the exact identity of the transmitter you are connected to.
PCI
(Physical Cell ID)
A low-level identifier used by the modem to distinguish one cell from another on the same frequency. 5G NR supports 1008 unique PCIs.
A low-level identifier used by the modem to distinguish one cell from another on the same frequency. 5G NR supports 1008 unique PCIs.
Frequency & Spectrum
NR
(New Radio)
The global standard for the 5G wireless air interface.
The global standard for the 5G wireless air interface.
ARFCN
(Absolute Radio Frequency Channel Number)
A unique code identifying the specific center frequency. In 5G, this replaces the LTE-specific EARFCN.
A unique code identifying the specific center frequency. In 5G, this replaces the LTE-specific EARFCN.
Band
Designated frequency ranges (e.g., n78 for 3.5GHz mid-band) used for transmission.
Signal Quality Metrics
| Metric | What it Measures |
|---|---|
| RSRP | Reference Signal Received Power: The primary measure of signal strength. |
| RSRQ | Reference Signal Received Quality: Indicates signal quality and noise levels. |
| SINR | Signal-to-Interference-plus-Noise Ratio: Measures signal purity for data speeds. |
Signal Quality Reference Guide
| Rating | RSRP (Strength) | SINR (Purity) | CQI (Quality) |
|---|---|---|---|
| Excellent | >-80 dBm | >20 dB | 13-15 |
| Good | -80 to -90 dBm | 13 to 20 dB | 10-12 |
| Fair | -90 to -105 dBm | 0 to 13 dB | 7-9 |
| Poor | < -105 dBm | < 0 dB | < 6 |
Note: dBm values are negative. -80 dBm is a stronger signal than -100 dBm.
Advanced 5G Signal Metrics
SS-Metrics
(SS-RSRP / SS-RSRQ / SS-SINR)
In 5G, measurements are taken from the Synchronization Signal (SS) block. Unlike 4G LTE’s “Cell-specific” signals, SS-metrics are the true gold standard for 5G coverage.
In 5G, measurements are taken from the Synchronization Signal (SS) block. Unlike 4G LTE’s “Cell-specific” signals, SS-metrics are the true gold standard for 5G coverage.
TA
(Timing Advance)
Used to synchronize timing with the base station. Lower TA usually means you are physically closer into the tower.
Used to synchronize timing with the base station. Lower TA usually means you are physically closer into the tower.
RSSI
(Received Signal Strength Indicator)
Represents total power received (including noise). RSRP is preferred over RSSI for accuracy.
Represents total power received (including noise). RSRP is preferred over RSSI for accuracy.
Network Architecture
NSA
(Non-Standalone)
A 5G deployment that relies on an existing 4G LTE core for control. Most common in early 5G.
A 5G deployment that relies on an existing 4G LTE core for control. Most common in early 5G.
SA
(Standalone)
Pure 5G using a dedicated 5G core network. Offers lower latency and better battery efficiency.
Pure 5G using a dedicated 5G core network. Offers lower latency and better battery efficiency.
MIMO
(Multiple Input Multiple Output)
Uses multiple antennas at both source and destination to multiply data capacity.
Uses multiple antennas at both source and destination to multiply data capacity.
Frequency Bands & Global Standards
B vs n
LTE bands use ‘B’ (e.g., B20). 5G New Radio bands use ‘n’ (e.g., n28).
⚠️ Note
700MHz Overlap
700MHz Overlap
Some modems simply report “Band 14” (a US Safety band) when they actually mean n28 or B28 in Europe. If you are in the UK and see B14, it is a display error for 700MHz.
UK Bands
- n78 (3500 MHz): High-capacity “C-Band”.
- n28 (700 MHz): Low-band for wide coverage.
- n1 (2100 MHz): Often used for 5G via DSS.
Regional 5G & LTE Deployment
Mobile networks vary by region. If your device reports a band not listed below for your region, it may be a reporting error.
| Region | Key Low-Bands (Coverage) | Key Mid-Bands (Speed) |
|---|---|---|
| UK & Europe | n28, n20 | n78 (3.5GHz), n1, n3, n7 |
| USA & Canada | n71, n5, n12, B14* | n41, n77 (C-Band), n66 |
| Asia | n28, n5, n8 | n78, n79 (4.9GHz), n41 |
*Note: Band 14 (700MHz) is a US-only Public Safety band.
5G Network Slicing (SA)
eMBB
(Enhanced Mobile Broadband)
Optimized for high-speed data, video streaming, and mobile internet.
Optimized for high-speed data, video streaming, and mobile internet.
URLLC
(Ultra-Reliable Low-Latency)
Mission-critical apps (autonomous driving, remote surgery) requiring <10ms latency.
Mission-critical apps (autonomous driving, remote surgery) requiring <10ms latency.
mMTC
(Massive Machine-Type)
Supports millions of IoT devices per square kilometer.
Supports millions of IoT devices per square kilometer.
Modulation & Channel Quality
CQI
(Channel Quality Indicator)
Value 0-15. Higher values allow the tower to use more efficient modulation.
Value 0-15. Higher values allow the tower to use more efficient modulation.
1024QAM
Advanced modulation on Android 14+ allowing significantly higher data throughput in perfect conditions.
5G NR CQI Table Index
The Table Index determines which modulation scheme the gNB (Base Station) can use to send data to your device. CellInfo displays this to show your current spectral efficiency.
Pro Tip: If your CellInfo app shows you are on Table 3 but your speeds are slow, the bottleneck is likely the backhaul (the fiber connection to the tower), not your radio signal.