Understanding CBRS & Private LTE Networks
Much has been said and heard about the rise of Private LTE Networks and how they will make our lives easier. But, thus far, for most people, and businesses, the term “Private LTE Network” is still a somewhat enigmatic phrase. What exactly are Private LTE Networks? What are they used for?
LTE (Long-Term Evolution) is a fourth generation (4G) wireless standard that provides increased network capacity and speed for cellphones and other cellular devices when compared to third generation (3G) technology. LTE has had a direct impact on the development of 5G. The current 5G standard uses the LTE control plane to manage 5G data sessions.
An LTE network employs the multiuser variant of the orthogonal frequency-division multiplexing (OFDM) modulation scheme, called orthogonal frequency-division multiple access (OFDMA), for its downlink signal.
OFDMA enables the LTE downlink to transmit data from a base station to multiple users at higher data rates than 3G, with improved spectral efficiency. Single-carrier FDMA is used for the uplink signal, which reduces the transmit power required by the mobile terminal.
The upper layers of LTE are based on Transmission Control Protocol/Internet Protocol, or TCP-IP, which results in an all-Internet Protocol network, like that of wired communications. LTE supports mixed data, voice, video, and messaging traffic.
LTE-A uses multiple input, multiple output (MIMO) antenna technology, similar to that used in the IEEE 802.11n wireless local area network standard. MIMO and OFDM enable a higher signal-to-noise ratio at the receiver, providing improved wireless network coverage and throughput, especially in dense urban areas.
The two main bands available for Private LTE are the 3.5GHz CBRS shared access band and the 5GHz global unlicensed band. In the United States, there is also the 2.5GHz band, which is divided into the Broadband Radio Service (BRS) and the Educational Broadband Service (EBS). Within this band, there is also the Rural Tribal Priority Window which was a unique opportunity for Tribes in rural areas to directly access unassigned spectrum over their Tribal lands in 2.5GHz.
Private LTE Networks - Advantages
LTE standard is used by the commercial Wireless Internet Service Providers (WISPs) as part of their cellular service offering. It is also used in private networks: A Private LTE is a network that is run specifically for the benefit of an organization, such as a local government, utility, factory, or police department. Only authorized users of that organization have access to the network. The organization decides where coverage will be provided, how the network will perform, who has access and who has priority. Because the network is owned by the organization then there will be no usage fees as there would be when a commercial WISP’s (carrier) services are used. Depending on the number of users and the amount of data sent over the network this can translate into substantial savings.
In addition to the financial savings, there are other advantages to owning an LTE wireless network:
- Coverage. This is the cornerstone of any wireless system’s requirements. With private ownership, the number and location of sites can be designed up front to meet the requirements of the organization; they also can be adjusted as needs change, such as if traffic signals or cameras are relocated or a new road where these will be used is built.
- Capacity. When device density does not coincide with the general population or changes due to specific activities, additional sites can be commissioned on a permanent or temporary basis as needed to support the required data volumes.
- Configuration and customization. In the consumer world, voice communication may have priority over other types of traffic, primarily data. In a network owned and operated by an electric power utility, data communication may require preferential treatment — the need to disconnect faulty circuits could take priority over any other traffic, for example.
- Upgrades and maintenance. The ability to plan upgrades or maintenance so that they do not interfere with the utility’s primary mission, as opposed to depending on a commercial carrier’s schedule, is a key element for mission-critical operations.
- Expansion. Electric power or water supply utilities exist in a dynamic environment. Mergers and acquisitions are common and such events may require network expansion. Experience has shown that incompatibilities between the respective communications networks can delay or diminish the integration of the involved utilities after an acquisition or merger.
- Access to multiple spectra (licensed, unlicensed or shared). The ability to mix and match spectrum can be advantageous because doing so may provide technical and financial advantages. For example, not all applications are equally sensitive, and devices that operate in the unlicensed spectrum may be significantly less expensive than equipment operating in the licensed airwaves. Also, different frequency ranges are characterized by different coverage performance; hence, mixing and matching them is another essential design optimization tool.
- Security. In addition to the cybersecurity features inherent to LTE, private ownership of a network provides an opportunity for total isolation from public networks, if so desired.
- Fault tolerance. This is crucial and often cited as the commercial wireless networks’ Achilles heel; commercial carriers design high levels of coverage overlap in high-density population areas and are just not that concerned about losing a site for a while. They also are reluctant to invest in physical security, backup power, redundant backhaul, and other measures required by other commercial users such as electric power utilities. With a privately owned network, the owner is in total control of the fault-tolerance aspects of network design.
- Fixed cost/revenue potential. Last but not least, private ownership provides not only a potentially higher level of control over costs, but also, in some circumstances, provides income opportunities borne of sharing excess resources with other entities.
Private LTE Network Applications
Based on the advantages listed in the previous section, the reader will surely think of many applications specific to her needs. However, it is worthwhile to highlight some of the ones that readily lend themselves to at least considering a Private LTE Network deployment:
- Manufacturing: Private LTE networks can be used to control and manage wireless robotic devices without building out additional connectivity infrastructure. For example, a manufacturing site could put all machinery sensors on a dedicated private LTE network. Manufacturing organizations could also ensure environmental sensors and monitoring runs seamlessly without interruption from network congestion. Placing proprietary apps on private LTE networks keeps sensitive traffic and data on-site.
- Warehouses: Security and surveillance video cameras, autonomous forklifts, telemetry data, GPS and/or Bluetooth device tracking, and supply chain applications can all run on a private LTE network to ensure operations run smoothly. The age of on-line shopping and distributed warehousing has undoubtedly increased the need for this type of solution.
- Mining: Between automated machinery, voice communications above and below ground, human-machine interfaces (HMIs), predictive maintenance applications, mobile devices for field staff, and crew welfare applications, mining sites require a great deal of network bandwidth. Private LTE networks can help these remote outposts prioritize traffic to ensure operational efficiency and crew safety.
- Airports: Security is critical element at any airport. With private LTE networks, airports can run remote diagnostics and incident reporting apps, as well as IoT devices for aircraft data and analysis with a higher level of security. Additional applications, such as digital signage, can also run on the private LTE network.
- Smart Cities: Private LTE networks will be critical as smart cities and smart buildings evolve. They will help power applications such as digital signage, smart lighting control, and security/surveillance with integrated recognition software and video analytics without interference from traffic on public networks.
- Hospitals: Reliability is vital for several critical communication applications at hospitals. With private LTE networks, hospitals can ensure critical care and health monitoring apps run securely and without interference. With private LTE, digital management apps, such as electronic health records, can ensure sensitive patient data is kept on-site and readily accessible. Many healthcare organizations currently rely on Wi-Fi networks to support an increasing number of mobile devices and IoT technologies. Offloading those devices from Wi-Fi network to a private LTE network allows facilities to support the devices cost-effectively with fewer access points. Hospitals could spend 30 to 40 percent less on wireless connectivity by moving devices from Wi-Fi to private LTE networks.
- Public Safety: Land Mobile Radio systems (LMR) are great for voice but are limited for data applications, whereas LTE networks are great for data applications. LMR Systems used by counties and cities, such as P25 PTT voice radio systems are the norm for public safety use. However, P25 does not lend itself well to wireless data transmission. For example, for video surveillance, private LTE networks provide a better, more affordable service and the best possible security without relying on mobile network operators. Emergency management personnel can use a private LTE network’s infrastructure to provide remote connectivity to highly specialized medical personnel in an emergency.
- Agriculture & Farming: Modern agriculture relies on targeted spraying. “Targeted Spraying” uses specialized machinery (and even drones) to spray pesticides only where they are needed on the farm. In addition to the obvious environmental benefits, targeted spraying helps enhance farm’s profitability by only spraying the herbicide where it is needed. Wi-Fi lacks the range and packet efficiency required. Wired connections simply aren’t practical outside of the farm office or backhaul where available. On the other hand, private LTE data services can now be deployed quickly, cost-effectively, and are easier than ever to manage. Producers on the family farm can deploy their own SIM cards to connect various equipment and machinery to the network.
Even cattle farming is made easier with wireless technologies. The data gathered by special collars worn by livestock can be sent over the LTE network to the cloud, where it is analyzed. Farmers and veterinarians can keep track of any suspicious changes in a particular animal’s data remotely, boosting the productivity and efficiency of the farm. Another application is in milk production. When the cow is ready to be milked, it enters the milking machine, and from there, the collar identifies the individual cow, allowing the machine to precisely latch on to its tits. The collar keeps a digital tally of each cow’s milk production.
