How to Plan a DAS Upgrade for Optimal Coverage: A Complete Guide

What is a DAS?

Distributed Antenna Systems (DAS) have become essential to enhancing cellular coverage within buildings and large spaces. Over time, though, even the most robust DAS installations require upgrades to keep up with technological advancements and increasing user demands. Here’s an in-depth guide on why, when, and how to plan a DAS upgrade.

An up-to-date DAS ensures that your building remains competitive and future-ready with enhanced wireless coverage, reduced costs, and compatibility with future technology, such as 5G and 6G.

A DAS, or Distributed Antenna System, consists of antennas and other equipment that amplify and distribute cellular wireless signals throughout a building or area. Think of it as a team of mini cell towers working together to blanket an area with strong, reliable cellular coverage. A DAS is usually installed in areas where there is weak or no cellular coverage or where there is high user density. Examples include stadiums, high-rises, shopping centers, campuses, and office buildings.

Why and when to upgrade your DAS?

The need for upgrading a DAS often stems from a combination of factors such as changing connectivity demands, outdated systems, support for existing infrastructure, and advancement in technology. Building owners and companies considering a DAS upgrade should look for the following indicators as signs of a system in need of an upgrade:

1. Degraded performance such as weak signal or low data speeds: If you begin noticing dropped calls, slow data speeds, and coverage gaps, then it is a clear sign that the DAS isn’t doing what it’s intended to do. Performance issues can arise due to various reasons: an increase in the number of connected devices, increase in data demand, new coverage area, improper antenna placement, lack of support for certain frequencies, etc. Since performance issues can frustrate users and impede productivity, it is imperative for buildings to upgrade their DAS in such instances. 

2. Increased maintenance and other hidden costs: If your DAS poses high maintenance and operational costs, that’s another sign of an aging system. These systems also often use outdated components that are becoming increasingly difficult and expensive to source, making repairs more costly and time-consuming. Older systems also typically consume more power leading to higher operational expenses. In such scenarios, the expense of upgrading the DAS will turn out to be more cost-effective in the long run.

3. Emergence of newer technologies: As wireless technology advances, legacy DAS systems may not support newer standards, protocols, and devices. For example, some of the older DAS may not support 5G, which could be a limitation for organizations that would benefit from the faster speeds, lower latency, and improved bandwidth of the newer technologies. The United Nations, for example, upgraded its DAS to support 5G earlier this year to enhance service quality in its headquarters. Older technology might be inefficient, translating into higher power consumption and increased cooling needs, further driving up operational costs. In some instances, an older DAS might be inferior to the cellular coverage provided by the carrier or WiFi-enabled cellular connectivity. An upgraded DAS will not only improve compatibility with advanced technologies like 5G but can also be made future-proof for emerging technologies like 6G. 

4. End of support from manufacturer: All devices have an end-of-life, after which the manufacturer stops providing support and services for the device such as software updates, security patches, and replacement hardware. For example, Stony Brook University Hospital utilizes a GE Enterprise Access Distributed Antenna System (DAS) to provide cellular and radio coverage in its buildings, but GE will no longer be supporting this DAS after December 31, 2024. It is critical to upgrade the DAS once it hits this stage as unsupported devices are prone to security threats, failures, and degraded performance.They also become expensive to maintain as you will need to find a third-party service provider to continue maintaining the DAS (like Stony Brook did). 

5. Evolving connectivity needs: As businesses change over time, their connectivity needs evolve as well. A business that earlier only needed indoor connectivity might now require connectivity outside the premises. Another business might need higher bandwidth to support an increase in the number of IoT devices that they’ve recently incorporated into their workflow. External events also play a role in changing requirements. For example, the COVID-19 pandemic dramatically increased the adoption of video conferences by business, necessitating the need for high-bandwidth, low latency connectivity. Such evolving needs can either be met by scaling existing DAS or upgrading the DAS entirely if the aging DAS cannot be expanded. 

6. Changing regulatory standards: Along with changes in technologies, regulators around the world are adjusting their requirements and safety expectations. Some of the older DAS might not comply with the latest regulations and upgrading them would not only be necessary to comply with the regulations but would also ensure compatibility with latest public safety technology.  

What factors to consider before upgrading your DAS

1. Assess coverage and capacity needs of the building: A planned upgrade starts with a thorough assessment of your building's wireless requirements including understanding the current and future coverage and capacity needs. Coverage refers to the basic ability to receive a signal throughout your facility, while capacity addresses the system's ability to handle multiple simultaneous users and high data demands. Some locations might require high capacity, while others might require high coverage. To accurately assess these needs, consider conducting a site survey for signal assessment. A professional DAS surveyor will analyze your building’s layout, materials, and current signal performance, giving you a clear picture of your building’s connectivity profile. Signal strength throughout a building can be surveyed using software such as iBWave that generates coverage heat maps. Additionally, you also need to decide which carriers and frequencies you wish to support. Supporting multiple frequencies will require higher-end equipment and might be more expensive. Schedule a site survey today.

2. Identify building characteristics: Every building has unique characteristics that influence DAS design and implementation. Building materials, floor plans, cable routing plan, architectural features, and any upcoming buildings nearby all play a role in coverage planning. An integrator will help advise during this process to identify and model building materials for RF propagation planning.

3. Study occupancy patterns and traffic: Along with capacity requirements, occupancy patterns determine the best placement of antennas and types of equipment to use. Peak usage times, user density, and traffic patterns are all crucial in determining the upgrade path. 

4. Identify technical and regulatory requirements: Does your building need to support public safety frequency and city-specific municipal frequencies? For example, building codes in some states require support for public safety systems but it must be independent from cellular DAS. The level of public safety coverage required also varies. Installing a DAS also requires clearances from carriers in some cases and must comply with FCC standards. Additionally, fireproofing considerations for DAS are necessary under some building codes. Your DAS vendor should be aware of these requirements and obtain necessary approvals to ensure you’re in compliance with local and national laws.

5. Understanding temporary implications: Will upgrading the DAS mean that the existing system will temporarily go offline, would this be an issue for operations, what’s the backup connectivity method, or can you choose a vendor who can upgrade the system while keeping it online?

How to choose the right DAS Solution

1. Select the right DAS vendor for the project: Selecting the right DAS vendor is crucial for a successful DAS upgrade. Key things to consider include:

1. Experience and track record: Has the vendor done previous installations in similar buildings and industry, do they have references from other property owners, do they have the necessary technical expertise and certifications, and what is their long-term viability?
2. Ability to obtain necessary approvals: As outlined above, installing DAS requires approvals from regulatory bodies, building owners, local authorities, and carriers. The vendor you choose needs to be well-versed with all the requirements and be able to cut through the red tape to obtain the necessary approvals in-time.  
3. How quickly can they deliver: Upgrading a DAS should not cost the company in lost productivity because of downtime or wait time. The ability to meet deadlines and deliver the project on time needs to be taken into account when selecting a vendor. 
4. Range of services: Some vendors offer end-to-end services, including planning, regulatory clearances, installation, and maintenance, which can simplify the upgrade process.
5. Support: Does the vendor have a local presence for maintenance and support, how fast can they respond in case of emergencies, will they provide training and documentation for maintenance and operation, and will they provide ongoing technical assistance?
6. Technology leadership: What’s the vendor’s innovation track record, are they 5G ready, do they take into account future upgrade paths, and do they integrate well with other technological infrastructure in the building?

2. Identify the right type of DAS for your needs: The market offers various DAS solutions, each with distinct advantages. Work with your DAS vendor to identify the right type of DAS for you.

1. Active DAS: An active DAS converts signals into optical signals and transfers them using fiber optic cables to different parts of a building. It offers the highest performance, flexibility, and scalability and is ideal for larger buildings (stadiums, convention centers, hospitals, etc.) but is more expensive than other types of DAS and requires approval from carriers. An active DAS for a single carrier costs between $2 and $4 per square foot and for a multi-carrier solution, cost ranges from $5 to $10 per square foot. 
2. Passive DAS: In this DAS setup, passive components such as coaxial cables and antennas are used to amplify and distribute the signal throughout the building. The signal is not converted to any other format. It’s more cost-effective (costs between $0.50 to $1 per square foot) for smaller installations and quicker to deploy, but has limited scalability and performance when compared to active DAS. A space under 500,000 square feet can generally be serviced by a passive DAS, while anything over 500,000 square feet will be better off with an active DAS.
3. Hybrid DAS: Combines parts of active and passive DAS, balancing cost and performance. Scales better than passive DAS.

3. Choose the right products and component manufacturers: Choosing the right supplier and component manufacturers is crucial to a well-performing and cost-efficient DAS. For example, if you choose a DAS equipment meant for a larger space (such as a stadium) for an office floor, you might be spending unnecessarily for no meaningful benefit. The component manufacturer also needs to be chosen based on requirements. A manufacturer that specialties in small-scale DAS products might be a better fit for small-to-medium sized DAS installations compared to a supplier that specializes in products meant for larger installations. Your DAS vendor should be able to help you narrow down the component selection.

What to do post-DAS installation?

1. Initial testing: Conduct various tests to check if the DAS meets the requirements of the organization or building.

1. Signal and coverage testing: This test includes using signal meters and specialized software to measure signal strength, data speed, and latency in various locations.
2. Capacity and load testing: Simulate high-user demand scenarios to ensure that the system can handle peak traffic without degradation in performance.‍
3. Interference testing: Check for potential sources of interference, which can include structural elements, electrical wiring, and other wireless systems within the building. Also perform a passive intermodulation (PIM) testing for identifying cable leakage and unwanted antenna noise.

2. Performance optimization: Once all the initial testing is done, the DAS can be fine-tuned for optimal performance. This includes adjusting antenna placement and fine-tuning them, adjusting power levels, signal balancing, and user experience verification. 

3. Preventative maintenance: Regular maintenance is not only essential for optimal DAS performance, but to also prevent costly breakdowns. Scheduled system health monitoring,periodic inspections to check for wear and tear on components, software updates and patches, performance monitoring, and regulator documentation are some of the measures that should be incorporated into the maintenance workflow. 

4. Emergency response plan: It is imperative to have an emergency response plan in case potential issues arise with the DAS to avoid downtime that affects operators. The plan should include 24/7 monitoring capabilities, rapid response procedures, spare parts inventory, backup systems and redundancy, and regular emergency drills.

5. Adapt to changing needs: Modifying the DAS as the signal needs of the organization changes helps keep the system up-to-date and performing optimally. Regular system assessments, capacity planning reviews, user feedback integration, technology roadmap, and budget allocation for DAS upgrade are all necessary to ensure the organization gets the best out of the DAS installation. Additionally, evolving public safety and carrier requirements might reshape DAS installations.

Our Case Studies

Enhancing the existing DAS for a Professional Sports Team Practice Facility in New York - In July 2018, a top New York sports team faced weak Verizon cellular reception within their advanced 105,000-square-foot training facility, despite having an existing distributed antenna system (DAS). With constant connectivity crucial for data-driven coaching and team communication, they approached RSRF for a solution. After analyzing the building’s challenging structure—constructed from materials like brick, steel, concrete, and glass, and filled with large athletic equipment—RSRF proposed an ancillary DAS to their existing signal booster was the most appropriate and cost-effective solution.  Following the installation and extensive testing, the facility now enjoys strong 4-5 bar signals for Verizon and AT&T. Read More

Upgrading the DAS in a large commercial office in Los Angeles: The new owners of a LEED Gold Certified, 2-building campus with tenants like Thomson Reuters and XPRIZE Foundation contacted us about Verizon coverage issues. Built 10-15 years ago, the campus had an existing Distributed Antenna System (DAS), but it covered only one of four floors and only supported AT&T. After inspecting the system, RSRF recommended a separate passive DAS powered by two Verizon small cells, covering all floors with two sectors. The project was completed in two months with hidden white cabling, providing consistent 4-5 bar Verizon coverage verified through a walk test. Read More.

Expanding coverage in a large manufacturing facility in Sherman, Texas: Finisar, a leading fiber optic equipment manufacturer in Sherman, Texas, initially installed AT&T and Verizon small cells to boost signal in specific areas but struggled with consistent coverage throughout their 400,000 sq ft facility, which includes manufacturing areas, offices, labs, and clean rooms. RSRF was brought in to build a robust DAS infrastructure that would integrate the existing small cells and ensure 5-bar service facility-wide. Challenges included high ceilings, machinery interference, and clean rooms requiring external antennas. RSRF completed the installation in phases, covering key areas as renovations progressed. This scalable approach saved Finisar $25,000-$30,000 while allowing their skilled IT team to handle basic maintenance independently, with RSRF available for advanced support as needed. Read More.

Installing future-proof 5G DAS for 23andMe HQ in Sunnyvale: When 23andMe began construction on their new 3-story facility in Sunnyvale, CA, they faced weak AT&T and Verizon signals due to dense building materials and metal-doped Low-E glass. RSRF recommended an ADRF active DAS powered by small cells from AT&T and Verizon, ensuring 5-bar coverage throughout without relying on external networks. The scalable DAS setup allows easy upgrades for future 5G needs and includes 24/7 monitoring via RSRF’s Network Operations Center. Delivered on time and on budget, the solution provided seamless connectivity from day one. Read More.