December 22, 2019
You may have heard how a distributed antenna system (DAS) can help you achieve superior coverage in your building. If your wireless service is a constant cause of complaints, DAS can give your guests and tenants the reliability that you’ve been searching for. But before you jump in, you should know that a DAS antenna design will look different for every building, depending on the size and specific issues you’re facing and DAS is sometimes not even the right decision at all!
If you’re interested in how a distributed antenna system (DAS) works before installing it, it’s helpful to get a sense of the mechanics behind it.
What Does DAS Do?
DAS either amplifies the cellular signals that your building already receives or deploys dedicated base stations. In either case the signal is distributed across the building via small size passive antennas. These small and discrete antennas can both send and receive signals on the licensed frequencies of the carrier. So, while it usually doesn’t create a signal, it can increase the functionality of the existing frequency so that guests and tenants can use their devices no matter where they are on the property.
Are There Different Types of DAS Networks?
Yes. The DAS antenna design you choose will depend on several factors. If you own a major venue that holds tens of thousands of people (carrying tens of thousands of devices), you may need a different design than a large, sprawling college campus or multi-use facility. It should be noted that DAS isn’t just meant for indoor use. It can ensure better coverage and capacity no matter where people are on your grounds.
How Is DAS Designed?
The in-building wireless solutions need to be designed to fit your building. Here are the main types of DAS and their basic designs:
With an off-air DAS, you’ll have a donor antenna installed on the roof that’s built to transmit the signals you already receive from your cell carrier. This is an example of a repeater-passive DAS because it amplifies what you get from your carrier. With the help of coaxial cabling, splitters, and couplers, the off-air system is a relatively simple system to deploy. This means it can be up and running quickly and without a serious price tag.
If you choose this option, you need to have an installer who understands the donor signal. If the signal isn’t strong enough, an off-air system won’t be able to optimize your coverage because the building simply won’t have enough input signal to work with.
An off-air system is generally recommended for those with coverage problems as opposed to properties that can’t handle an influx of traffic. So, if your network fails when too many people use too many devices, this may not be your best option. However, if you constantly hear of dropped calls in certain parts of the building or on certain areas of your grounds, this could be the perfect solution.
A Base Transceiver Station (BTS) is a source of cellular signal and allows the RF signal to be broadcast over the entire DAS network. The BTS is what makes it possible for a cellphone tower to produce the signal, and it’s connected to the antennas through a fiber connection. The fiber optics used need to be dedicated to DAS otherwise it could interfere with the overall coverage.
This type of system is usually recommended for crowded and in-demand areas, such as airports. These major venues may even need multiple BTS devices to function properly. As you might imagine, a BTS DAS is not an easy or inexpensive design, but it is often the only way you can handle the increased capacity in a building.
BTS is an example of active DAS because it uses active elements. It can work with either single carriers or, more likely, multiple carriers. The signal is moved through the fiber optics, allowing connectivity to reach virtually every part of the property.
Hybrid distributed antenna systems DAS will use both active and passive functionality. It relies on both fiber optic and coaxial cabling to eliminate any and all pockets that lack wireless coverage.
With a hybrid system, your equipment will be based on the size of your building, the strength of the available signal, and the current and expected capacity in your building. These systems are a compromise both in terms of the time it takes to install and the overall cost of the system. So, while it’s not as budget-friendly as a passive, it’s more affordable than an all-active system.
Tips for DAS Deployments
There are several reasons why you may want a DAS for your building. Maybe you struggle with fortified construction in the basement or parking garage. Maybe the building is too far from a cell tower. Maybe you’re concerned with how public safety will be affected if people can’t get through to emergency services on your network.
If you want to ensure that your wireless signal will hold up, it helps to pick the right integrator. DAS can be difficult to configure, and most property owners don’t have the technical knowledge to determine the best system, equipment and design to use.
To take some of the burdens off your shoulders, you should look for someone who understands how to save you money and time. For example, you may be able to use capacity aggression to optimize the performance of your base stations. Or you may be able to use small cells rather than DAS. Both workarounds can simplify the installation process and save you money on potential DAS solutions.
Experts in DAS Antenna Design & In-Building Wireless Solutions
DAS can be complicated to design in even the most straightforward of buildings. As the project progresses, you may encounter hiccups involving anything from the signal source to the carrier’s equipment.
Connectivity Wireless can help you determine what resources you have and how you can use those resources to meet your tenant’s expectations. We’ll also help you prepare for what’s on the horizon, e.g., 5G, IoT, so that your DAS can handle the next wave of technologies.