Cellular Signal Is Critical to Occupancy Rates
Two decades ago, at the beginning of the millennium, a building – whether commercial, residential, or mixed-use – having a strong cellular signal was a benefit. Today it’s a non-negotiable requirement. As more businesses and individuals rely strictly on their mobile phones and wi-fi for voice and data communications (as opposed to landlines and dial-up connections), a mixed-use building with spotty coverage may have a difficult time finding both residential and commercial tenants.
In fact, before signing a lease, it’s not uncommon for tenants of both types to check signal coverage in various locations throughout the space. For commercial spaces ranging from office spaces to restaurants, and everything in between, tenants want to ensure that their guests can use their devices whenever and wherever, and that their staff are able to complete business-critical tasks without interruption or delay. In residential spaces, tenants will want to know that whether they’re working from home or just binging the latest streaming series, their connection won’t falter.
What Causes Poor Cellular Reception?
It’s probably unsurprising to hear that cellular signals are often strongest outdoors. With fewer obstacles in their way, signals can travel unimpeded from the tower to the devices. Unfortunately, many buildings – especially large, mixed-use ones – have weak signals. The signal may be strong in wide-open common spaces, such as lobbies or loading docks, but due to the construction and layout of the buildings, the further in – or the higher up – you get, the more the signal diminishes.
The divided layout of mixed-use spaces means the signal has to pass through more floors, ceilings, and walls, getting weaker with each obstacle it encounters. During an emergency situation when building occupants may be taking shelter in infrequently used spaces like closets, storerooms, vaults, or stairwells, it’s imperative that cellular signals are strong enough for them to call for help or for first responders to receive a signal during the course of the incident.
Similarly, the larger a building is and the more inhabitants there are, the more devices are typically competing for a spot on the network. As network congestion increases, cellular strength decreases, leading to dropped calls or insufficient signal strength. This is doubly true during public safety incidents where dozens of first responders may flock to the location.
How To Remedy Poor Indoor Cellular Signals
In order to ensure that there’s a strong, reliable cell signal throughout the entire building – including in parking garages, on the roof, and in commonly unused spaces such as storage areas – property developers can deploy a Distributed Antenna System (DAS) to amplify cellular and wireless – including FirstNet – signals.
The function of a DAS is to amplify existing signals and circumvent physical obstacles that prevent the signal from reaching its entire intended coverage area. One of the ways of doing this is to position antennas outside of a building to capture the signal and then position the antenna so that it’s pointed in the direction that needs coverage.
Flexible Signal Source
In order to facilitate strong cellular signals, it’s necessary to circumvent obstacles – such as walls or surrounding buildings – that may be blocking them. To do this, antennas are positioned outside of the building and configured to direct cellular signals from the towers and into the building at the desired location.
In the event that the signal is too weak to be sufficiently amplified within the building, which is common in rural areas or areas where there are high hills or very tall buildings, small cells – which look similar to a Wi-
Fi router – may be installed inside the building. These devices bypass the cell towers and deliver a signal directly to the building. While the cell towers are designed to distribute a signal over a very large area, the small cells are used to provide a signal to small, focused areas.
Analog versus Digital
The signal is transmitted to the internal antennas after first being delivered to the head-end (control center) of the cellular amplification system. From there, the signal is rebroadcast throughout the building and to user devices by the internal antennas.
Older analog technologies push the passive DAS signal out via coaxial cable, which, unfortunately, degrades the signal over the distance of the cable. Digital-based technologies, however, take the source signal and digitize it. The signal is then distributed via Category 5 ethernet cable, which doesn’t cause signal loss. Ethernet cables also have the added advantage of being able to supply power directly to the antennas, so no additional outlets and electrical wiring are necessary to deploy the solution.
Active DAS systems use fiber for some or all of the signal distribution, allowing signals to travel much further and at high volumes. However, for buildings smaller than 500,000 square feet, fiber solutions aren’t ideal as they are much more expensive than other options that will still provide excellent coverage in smaller buildings.
Stronger Signals Means Better Coverage
Cellular signals arrive at buildings at a certain power level. Since these signals can vary between very low or very high – or somewhere in between – many solution providers will require an RF site survey before designing a system so that they know how much “gain” they’re trying to achieve.
The signal power from internal antennas determines the system’s coverage footprint – and the more power that’s delivered, the bigger the footprint will be. Solution providers will try to get the signal power as close to FCC regulatory limits as they can (without exceeding them) in order to provide as large of a coverage footprint as possible throughout the building.
Gain is measured in decibels (dB), and the maximum allowed gain for bidirectional amplifiers (BDA) passive DAS repeaters is 70 dB. Carrier-specific smart passive DAS and active hybrid DAS are allowed up to 100 dB gain. Gain is calculated exponentially, which means that a 100 dB gain increase is a 1,000 times stronger signal.
Smart Systems Provide Superior Experience
Cellular signals don’t operate within a static environment. Since the environment is variable and there are ever-changing factors that can affect the signal strength, systems that have smart capabilities and can adapt are able to provide optimal performance.
Some of these adaptive behaviors include being able to amplify certain carrier signals while filtering unwanted signals to limit noise on the network and deliver better quality of service. Similarly, echo-canceling capabilities will allow a unit to produce more power and a larger footprint without the risk of negative outcomes.
Types of Distributed Antenna Systems (DAS)
Property developers can choose between two primary types of Distributed Antenna Systems – active DAS and passive DAS – to provide an amplified signal to their mixed-use properties. However, the two solutions are not equal, with each option being better suited to specific scenarios than the other.
While an Active DAS can essentially generate its own network signal, Passive DAS relies on an already adequate signal to pull from in order to redistribute and amplify it.
Distributed Antenna Systems for Public Safety Communications
In addition to providing multi-use building occupants with the convenience of better signal strength, there’s also another major reason for property owners and managers to consider deploying DAS – public safety.
A weak signal throughout a building can be inconvenient, but when there’s no signal in the event of an emergency situation, it could be a matter of life and death.
Subterranean Cellular Signal
In order to provide tenants of a 58-story building with cellular signal in the 400,000 square foot, three-story subterranean parking garage, the owner of a Dallas, TX building initially planed to install a traditional Active DAS solution. However, three years into the project there was no end in sight, so the owner transitioned to a new solution provider and an active DAS hybrid. Once they signed the agreement for the hybrid solution, the project was completed in 61 days – and at less than half of the initial budget.
Less than 30 minutes away, in Frisco, TX, the owner of a five-story, 430,000-square-foot apartment building with a four-story parking garage needed to find a way to provide a cellular signal to the garage. The apartments around the perimeter of the building were receiving signals, but the further into the interior of the space tenants went, the worse the signal was, and there were concerns about safety in the parking garages and other spaces.
An Active DAS hybrid solution was deployed, with antennas situated on the second and fourth floors of the building. The signal strength from those antennas was strong enough to penetrate the rest of the building, with signal on the first, third, and fifth floors being 95% of the strength. A Passive DAS branch was installed in the parking garage to ensure signal strength there.