Compare Sky Mobile with SMARTY Network

Features
Network Provider O2 Three
Check network coverage: Sky Mobile coverage SMARTY coverage
5G Network Yes Yes
5th generation network. Max data speed of 10 or 20 Gb/s.
4G Network Yes Yes
4th generation network. Max data speed of 1 Gbps (1000 Mb/s).
3G Network Yes Yes
3rd generation network. Max data speed of 42 Mbps.
2G Network Yes Yes
2nd generation network. Max data speed of 0.3 Mb per second.
WiFi Calling Yes Yes
Use Wi-Fi for mobile phone calls and texts when no network signal.
4G Calling (VoLTE) Yes Yes
Voice over LTE (4G Calling) makes clearer HD calls over 4G networks.
Data Rollover Yes No
Unused mobile data allowance rolled over from one month to the next.
Tethering Allowed Yes Yes
Tethering allows you to share your mobile internet with other devices.
eSIM No No
e-SIMs are digital virtual SIM cards downloaded onto supported mobile handsets.
Network Frequency Bands
5G (NR) Frequency 3500 MHz 3500 MHz
4G (LTE) Frequency 800 / 900 / 1800 / 2100 / 2300 MHz 800 / 1500 / 1800 / 2100 MHz
3G (UMTS) Frequency 900 / 2100 MHz 2100 MHz
2G (GSM) Frequency 900 MHz N/A MHz

Launched to the public in January 2017, Sky Mobile operates as a full MVNO (Mobile Virtual Network Operator) within the UK, utilising the O2 radio access network infrastructure.

SMARTY is a UK mobile virtual network operator running on the Three network. SMARTY offers SIM-only plans with no lengthy contracts or credit checks, and provides monthly discounts on unused data from previous months.