In most parts of the world a spectrum licence will be required in order to operate an LTE network. Fortunately, while such licences were previously limited to a handful of network operators who paid huge sums for exclusive spectrum access, there are increasily schemes available which provide shared access at a relatively low cost. Examples of which include Ofcom Shared Access spectrum in the UK and CBRS band in the US.
The initial focus is on configutation for LTE Band 3 (1800 MHz) and the Ofcom Shared Access 3.3 MHz (x2 for uplink + downlink) allocation within this. Documentation will be updated over time to add details of licensing schemes in other countries.
LTE networks operate in licensed spectrum and operating equipment without a licence from the regulatory authority in your country is likely to be a crime punishable under applicable law.