How to build your private LTE network

Private LTE networks are becoming increasingly popular due to reduced complexity and operational costs. Historically, building cellular networks has been limited to large companies with deep pockets. Until now, licensing spectrum, purchasing radio infrastructure, and developing and maintaining core network layers have been resource-intensive investments. Building a private LTE network can be done “easy.” Read on to learn how to build a private network.

Benefits of Private LTE

Running a network privately can improve service quality, reduce latency, and increase data security. As a private network operator, you have control over both the physical and digital infrastructure. To improve network coverage in remote areas or areas of radio interference, additional base stations can be installed.

Digital infrastructure is responsible for managing cellular connections and secure data routing. The so-called core network can be installed on private servers to ensure that data never leaves a trusted domain or physical site.

If data processing happens locally, latency can be significantly reduced, which opens up new opportunities for new use cases. When you run the network privately, you can also control your expenses. After the initial capital expenditure investment to purchase and install the physical infrastructure, the operating costs are almost zero since there are no data charges to pay.

How to set up your private LTE network

The 5 things you need to run your private LTE network are:

1. Spectrum
2. Physical Infrastructure
3. Digital infrastructure
4. Client Device
5.SIM card

Let us discuss all the components one by one.

1. Spectrum – licensed, unlicensed or shared

Licensed spectrum

Licensing the rights to use a specific frequency band can get very expensive. Spectrum is usually licensed by federal organizations through spectrum auctions. Since spectrum is a scarce resource, you’ll need millions or even billions to license a portion of spectrum. Fortunately, some network operators are willing to license a portion of spectrum so you can build your own private LTE network.

Unlicensed spectrum

Some parts of the spectrum are unlicensed and can be used without approval from the authorities as long as the hardware is certified. E.g. you can set up a WiFi router without going through the legal process. Depending on the country you operate in, you can use unlicensed spectrum for your private LTE network.

Shared spectrum

As of 2015, the US FCC opened up the 150MHz band for shared use, allowing companies to deploy private networks without the need for licensed spectrum.

This frequency band ranges from 3550 to 3700 MHz and is also known as the 3.5 GHz band, LTE Band 48, or CBRS (Citizens Broadband Radio Service). The CBRS band is available for commercial use without the need for a large investment to obtain a license for a specific frequency. CBRS is ideal for running private LTE and even 5G networks.

2. Physical infrastructure

To build a private network, specific hardware is required. This is called an eNodeB, base station, small cell, or CBSD (when the hardware is designed for the CBRS band). The eNodeB forms a bridge between the physical and digital worlds as it converts electromagnetic radio waves into digital data. It communicates with physical end devices as well as the digital core network.

Although public LTE infrastructure may seem large and expensive, you can already buy small eNodeBs for a few hundred dollars. Suppliers include Baicells, Airspan, Foxconn, Telrad, T&W, and Ubiik, among others.

3. Digital infrastructure

The core network, also known as the Evolved Packet Core (EPC), is the digital network component that manages device connections and routes data to the correct endpoint. It consists of two components: the control plane and the data plane. The control plane is responsible for tasks such as authentication of user devices and generation of encryption keys, as well as managing and configuring the eNodeB. The data plane is responsible for the actual routing of telemetry data.

4. User equipment

User Equipment (UE) refers to devices that use a private network. Typically, UEs contain sensors to sense their physical environment and send data to the cloud. They require a cellular radio modem that supports the frequencies used by cellular networks.

Devices operating on the network may also be customer premises equipment (CPE). CPE converts LTE network signals to a different communication standard, such as WiFi or wired Ethernet, and vice versa.

5.SIM card

In order to set up a private LTE network, a SIM card is required. Each SIM card contains an IMSI (a unique code that describes the user's identity) and some security keys.