Plain English definitions for common 5G FWA terms.
A-C
APN (Access Point Name): The network address your router uses to connect to the internet via the mobile network. Different operators use different APNs. Most modern routers auto-detect the APN from the SIM card, but it can be set manually in the router admin interface.
Band: A specific frequency range allocated for cellular use. 5G in the UK uses several bands including n28 (700 MHz) and n78 (3.5 GHz). Your router must support the bands your operator deploys at your location.
Beamforming: A technique used by 5G base stations where the antenna array focuses the radio signal as a directed beam toward a specific user device, rather than broadcasting in all directions. Improves signal quality and capacity.
CGNAT (Carrier-Grade NAT): A system where many customers share a single public IP address. Most consumer mobile data SIMs use CGNAT. Means your router does not have a directly routable public IP address, which prevents inbound connections but also prevents you from hosting services accessible from the internet.
CPE (Customer Premises Equipment): The hardware installed at a customer’s property to receive a 5G signal and distribute it locally. Ranges from indoor desktop units to outdoor weatherproof units.
D-G
Downlink: Data travelling from the network to your device. What you measure when you run a download speed test.
eSIM (Embedded SIM): A SIM that is built into the device rather than being a removable physical card. Allows operator profiles to be loaded over the air without physically swapping a SIM. Increasingly common in modern routers and CPE.
FWA (Fixed Wireless Access): A method of providing broadband using a wireless connection (cellular, in the case of 5G FWA) to a fixed location, rather than a physical cable.
gNodeB (gNB): The 5G base station. The radio access point on a mast that your CPE connects to.
L-M
Latency: The time taken for data to travel from your device to a server and back. Measured in milliseconds. Lower is better for real-time applications. Typical 5G SA latency is 10-20 ms.
MIMO (Multiple Input Multiple Output): A radio technology that uses multiple antennas to transmit and receive multiple data streams simultaneously, increasing throughput. 4×4 MIMO has four transmit and four receive antennas.
mmWave (millimetre Wave): 5G spectrum in the 24-100 GHz range. Enables very high speeds but has very limited range. Used in specific dense urban deployments in the UK.
N-R
NSA (Non-Standalone) 5G: A 5G architecture that uses the 4G core network alongside a 5G radio layer. The first widely deployed 5G architecture. Most current 5G deployments in the UK are NSA or mixed NSA/SA.
n78: The 5G band designation for 3.5 GHz spectrum. The primary mid-band used by all UK operators for urban and suburban 5G. The most important band for FWA performance in most UK locations.
n28: The 5G band designation for 700 MHz spectrum. Used by EE for extended rural 5G coverage. Long range, lower capacity than n78.
PoE (Power over Ethernet): A standard that allows electrical power to be delivered over an Ethernet cable alongside data. Used to power outdoor CPE units from an indoor PoE injector via a single Ethernet cable.
RSRP (Reference Signal Received Power): A measure of 5G/LTE signal strength in dBm. Above -80 dBm is strong; -80 to -100 dBm is usable; below -100 dBm is marginal for FWA use.
S-Z
SA (Standalone) 5G: A 5G architecture using a purpose-built 5G core network. Enables lower latency, network slicing, and advanced 5G features. UK operators are progressively rolling out SA 5G.
SINR (Signal to Interference plus Noise Ratio): A measure of signal quality relative to interference. Above 10 dB is good; 0-10 dB is moderate; below 0 dB indicates significant interference.
SRN (Shared Rural Network): A government-funded programme under which UK operators share infrastructure to extend coverage to rural areas. EE, Vodafone, Three and O2 each build masts that are shared among all four operators, reducing the total number of masts needed and extending coverage to underserved areas.
Sub-6GHz: 5G spectrum below 6 GHz. Includes the n78 (3.5 GHz) and n28 (700 MHz) bands used for most UK FWA deployments.
Uplink: Data travelling from your device to the network. What you measure when you run an upload speed test.