Answering the Call at TD Garden

By Damian Schmalz, PE, and Ben Revette, PE

TD Garden is home to two of New England’s favorite and storied sports teams, the Boston Bruins and the Boston Celtics. The arena also hosts concerts, ice events, family shows, wrestling matches, and more. Originally constructed in 1995 to replace the historic Boston Garden, the 19,600-seat facility welcomes, on average, nearly 3.5 million guests a year. It’s no surprise that since its construction, communications technology has made significant advancements.

Coverage at that time consisted of external cell sites leaking radio signals into the stadium for a limited number of patrons with cell phones. As cell phone adoption increased dramatically, the external system was soon overwhelmed.  The wireless carriers began developing internal cell sites and eventually moved to fiber optic-based distributed antenna systems (DAS) to meet coverage demand.  Dewberry was engaged to support AT&T, a client the firm has worked with for more than two decades, to improve the telecommunications system and coverage throughout the interior and exterior of the arena. In 2012, Dewberry supported the original design for the interior neutral host (multi-carrier) DAS within the TD Garden that enabled visitors to use their “smart” phones, which were gaining in popularity around that time, for data-driven applications beyond just voice and texting.

However, just a few years later, that infrastructure was already considered antiquated technology. In today’s world, arenas are filled with smart phones and a myriad of other devices that are being used as video cameras, social media interfaces, internet browsers, food-ordering systems, and even apps to interact with the jumbotron. Data traffic, once measured in giga bytes, has grown to tera bytes of data at a single event. While AT&T and other wireless operators have worked to update their systems inside sporting arenas and large stadiums across the globe, new radio spectrum allocation and fifth generation technology standards (5G) required the system to be completely overhauled to keep pace with demand. In 2019, Dewberry was once again called in to support AT&T to bring the next generation of communications infrastructure to the TD Garden.

Infrastructure that Meets the Needs of the Modern-Day Sports Fan

Dewberry has been supporting AT&T in their efforts to remove old, outdated systems, and implement new systems that improve cell coverage and capacity throughout the entire arena, including the newly renovated suites and press boxes, concourse levels, and in the main seating areas. This project consisted of replacing the DAS radio equipment, antennas, cabling, and associated supporting equipment throughout the arena with updated equipment compatible with new spectrum and emerging technologies. In order to provide enough coverage and capacity to meet the demand expected, AT&T installed more than 600 antennas, nearly 200,000 feet of cabling, and eight intermediate supporting equipment locations.

Of all the areas where coverage improvement was most needed, the main seating bowl section was a primary objective for AT&T. This area had previously seen reduced coverage due to the physical limitations for antenna placement on existing infrastructure and within the arena architecture. AT&T’s solution consisted of a combination of multi-beam and single-beam antennas across the entire catwalk level of the arena. In total, the catwalk installation included 61 single beam antennas, eight multi-beam antennas, and 64 custom remote enclosures on the catwalk level of the arena. Additionally, eight new steel beams were installed to fill in gaps between existing steel infrastructure where new antenna implementation was required.

To achieve their goals, AT&T turned to Dewberry to develop custom antenna mounting brackets for each of the proposed antennas; coordinate with arena structural engineers, system integrators, and radio frequency (RF) engineers to implement the new steel beam sections; and design custom enclosures that would meet the requirements and specifications of the radio equipment installed inside. The custom brackets were designed to accommodate in-field adjustment in both horizontal and vertical planes while minimizing size and visual impacts due to the location of antennas near the center of the arena. In order to test the effectiveness of the brackets, Dewberry developed them from the concept stage using 3D modeling software, and then worked with a steel fabricator to create prototype brackets, which were fabricated and installed on test beams. Due to the location of the equipment directly above the playing surfaces and general public areas, the brackets featured safety measures, such as aircraft cabling safety ties, multiple attachment points for redundancy, and cotter-pin incorporation for all bolted connections, so no mechanical connections would come lose due to vibration.

Flexibility, Creativity, and Coordination

Working in such a large-capacity venue comes with its own set of challenges, some that Dewberry has also faced when integrating these systems at football stadiums, college campuses, airports, and multiuse complexes. The more people a venue holds, the more stakeholders involved behind the scenes. Balancing the timeline of so many teams can be tricky—everyone needs to perform their work effectively and each group is vying for the valuable and often limited time available for the projects. Frequently, facility upgrades of any kind can only occur during off-hours. With a venue like TD Garden that is constantly hosting high-profile events, those off-hours can be few and far between. Learning to be flexible, nimble, and work among other stakeholders is paramount. For instance, Dewberry had the opportunity to work directly with the venue’s structural engineer on the analysis of the existing catwalk support structure for the proposed equipment as well as in the design and installation of new steel support beams. Dewberry then had to provide coordination between the venue structural engineers, steel fabricators/installers, and AT&T to make sure everyone’s priorities were addressed.  By doing so, the firm was able to meet the needs of AT&T, while making sure the venue’s engineering group was involved and approved of the installation, thus streamlining the installation process and reducing the amount of scheduling and coordination required with the owner.

In the end, regardless of how fast technology may change and the number of “G”s on your phone, the formula for successful project delivery remains unchanged. Upfront preparation, open stakeholder communication, thoughtful and thorough design, and continuous client support will deliver a successful project for everyone involved.

Damian Schmalz is a senior project manager and professional engineer in Dewberry’s Boston, Massachusetts, office. He has more than 10 years of experience and has a multi-faceted background in civil and telecommunications engineering, specializing in DAS for major transportation systems, large sports/convention venues, university campuses, and high-rise buildings.
Ben Revette is an associate vice president and professional engineer in Dewberry’s Boston, Massachusetts, office. He has been with the firm for 20 years and leads Dewberry’s national telecommunications engineering team.