By Arnold Kim
For facility owners, wireless connectivity has a greater direct impact on business strategies and innovation now than during the 4G/LTE era. 5G supports technologies such as mobile edge computing (MEC) for ultra low latency data transmission, massive IoT, broad VR/AR use cases, and autonomous machinery, all of which fundamentally change how business is conducted.
However, the path to install an effective 5G wireless system is more complex and nuanced than for 4G/LTE. This is due to vastly different frequency band characteristics and the addition of more wireless technologies to architect in-building networks, such as small cells, distributed antenna systems (DAS), and repeaters. Facility managers should understand the 5G landscape to inform their decisions on building a cost-effective indoor wireless network and avoid a costly rip-and-replace or overhaul in the near future.
More Spectrum, More Considerations
The sheer number of 5G frequency bands expands options in selecting the best 5G solution for each business case. Unlike 4G/LTE, where frequency bands share similar characteristics, the ones used for 5G (categorized as high-band, mid-band, and low-band) offer different speeds and limitations.
High-band consists of mmWave frequencies such as 24GHz, 28GHz, and the upper 37GHz, 39GHz, and 47GHz bands, which give 5G its gigabit speeds and low latency. Unfortunately, the bands travel very short distances and are easily obstructed by natural or man-made barriers, such as rain, vegetation, metal, brick, and low emission glass. Symbolically, mmWave is similar to a “hot spot” for wireless, offering powerful connectivity in a small, densely populated area. Because of this, facility owners will need to deploy more wireless hardware for coverage per square foot to compensate for coverage and capacity needs.team
Whereas high-band is all capacity and limited coverage, mid-band 5G can be thought of as a balance of the two. Facilities owners won’t receive the same low latency and high-speeds as with high-band, but the signal is more resilient and has better propagation. Mid-band includes 2.5GHz, 3.5GHz, and more recently C-band, which is 3.7-3.98 GHz.
Low-band 5G is excellent for very wide coverage areas but has the most limited speeds of the three categories. Frequencies include 600 MHz, 800 MHz and 900MHz bands, making this type of 5G spectrum, along with mid-band, critical for connecting rural areas. In fact, Anterix established a 900MHz ecosystem for the utility sector, where facilities are often located in remote locations.
All of this spectrum is critical for mobile carriers to realize their nationwide networks, but with so much diversity it can be daunting to understand how it impacts in-building design.
Understanding 5G Network Architectures
Before investing in 5G in-building deployments, facilities owners must have a clear understanding of their business needs for wireless. For example, a manufacturer might require mmWave to power autonomous factory machinery, but not for the entire facility. It is far more cost-effective to support a mix of high-band and mid or low band coverage in this case. There are also uncontrollable factors such as facility location (i.e. urban or rural), size, and base station proximity. A building in the heart of a major city is going to have an easier time bringing in mmWave than a utility company in rural America.
For facilities of 100,000 square feet or less without an existing base station, small cells are likely the most cost-effective option for 5G in-building networks. They are essentially a less expensive base station and provide additional capacity (increasing how many users can leverage wireless in a single location).
There are two limitations with small cells to consider when choosing a wireless network. First, small cells don’t currently provide support for multiple frequency bands such as 600 MHz, 2.5GHz, 3.5 GHz, etc. Facilities that wish to build a network with a combination of high-band and mid-band spectrums require multiple small cells just to bring capacity for each band to a single area. This adds hardware and backhaul costs. The second limitation is that small cells provide capacity, but not coverage. For mmWave especially, more coverage is essential as it has very limited range and is easily disrupted by obstacles. Facilities will require a lot of small cells to bring mmWave to the entire location.
For facilities of 500,000 square feet or larger, a hybrid wireless solution of small cells and modular distributed antenna systems (DAS) is preferable due to extensive coverage needs. Whereas one small cell brings capacity for one frequency band, a modular DAS provides coverage for multiple bands. Facilities can begin supporting one band and grow to support others in the same form factor without needing to build or retool their network environment. This is a critical characteristic of a future-proof 5G network. Consider a scenario where a facility uses only small cells to support one band now and others in the future. The interference created by additional bands could significantly disrupt the radio frequency (RF) environment. In a hybrid use case, a small cell would bring the capacity and connect to a DAS solution to expand the coverage across the area through a series of remote units and antennas.
The more knowledge facilities owners have about 5G, the better equipped they will be to successfully deploy an in-building wireless solution to meet their needs at a lower cost. All 5G is not created equal, and making sure a facility can support most of the spectrum will help them mitigate project delays, implementation challenges, or disappointing outcomes.
Kim is Chief Operating Officer at Advanced RF Technologies, Inc. (ADRF), a TL 9000 and ISO 9001 certified Original Equipment Manufacturer (OEM) of in-building wireless solutions. Tasked with handling the day-to-day operations for the company, he has 15 years of experience in the telecommunications industry. Prior to joining ADRF, Kim worked at Bear Stearns, Evercore Partners, J.P. Morgan, and Salomon Smith Barney, where clients included ARINC, EarthLink, Frontier Communications, Global Crossing, MRV Communications, Motorola, Sorrento Networks, SK Telecom, Teleglobe, and WaveSplitter Technologies. He earned his MBA in Finance and Economics and his BA in English and Economics, both from Columbia University.