How AT&T is using small antennas to fix big problems

If all goes according to AT&T’s wishes, the city of Palo Alto may soon become the premier testing spot for Ma Bell’s plan to boost its cellular network power by installing a large number of small cellular antennas around town. Ostensibly billed as a method for AT&T to overcome terrestrial and urban challenges in Palo Alto, the small-antenna plan for Silicon Valley’s cultural nexus is also part of a big nationwide push of Distributed Antenna System (DAS) technology deployment by AT&T to help Ma Bell get its overtaxed cellular network back up to speed.

Historically used to improve cellular coverage inside buildings, DAS is basically a method to deploy a series of synchronized smaller antennas instead of a larger, cellular antenna array, such as those found atop buildings or on the unsightly antenna towers that are now a common part of the urban landscape. Inside a building, a DAS can help improve cellular reception by bringing small antennas closer to users inside, who then don’t have to connect their cell phones through walls or windows. A typical DAS system might then route the internal antenna connections to a stronger antenna connection on the roof to link to the parent cellular network, improving throughput while conserving device and antenna power.

In Palo Alto AT&T is proposing to build out about 80 new DAS tower sites, placing them atop regular utility poles in and around Palo Alto’s leafy downtown area. If the plan wins city approval Palo Alto’s AT&T customers should see marked improvement in cellular connectivity, simply due to the increased number of available towers that can connect iPhones and other devices back to AT&T’s network. According to AT&T’s extensive Palo Alto wireless information web site, the proposal has been submitted to the city but no decision has yet been made.

This is what a DAS antenna in Palo Alto might look like in the wild. Credit: AT&T.

According to industry insiders, AT&T has recently committed significant internal resources to stepping up its DAS deployment efforts nationwide — indeed, AT&T mentions DAS deployments prominently in several recent press releases touting network improvement plans in cities including SeattleHoustonDallas and Kansas City among others. For AT&T, using DAS deployments seems to make a lot of sense — given that the company’s current network suffers from a lack of backhaul capacity, it might be easier for AT&T to more quickly increase its cellular reach by installing a lot of smaller antennas than by trying to significantly upgrade existing antenna deployments, since the latter method could involve expensive, time-consuming acts like ripping up streets to bring fiber connections to tower sites.

Smaller DAS antennas might also pass civic muster more quickly than new traditional cell-tower deployments, which generally take a year or more of paperwork for all licensing and regulatory clearance even when there is no neighborhood opposition. And as all cellular service providers know, opposition to new cell towers is almost a given, so outdoor DAS may be the wave of the future should AT&T’s Palo Alto deployment prove successful.

AT&T infographic explaining the need for DAS in Palo Alto.

AT&T is also planning to build out a public Wi-Fi hotspot in Palo Alto, much along the lines of similar deployments in New York and Chicago. Though AT&T has touted the hotspots as a successful strategy, our attempts to ask AT&T to quantify the usage of said hotspots has so far gone unanswered. From an industry standpoint the DAS deployment has more far-reaching ramifications especially with AT&T’s planned launch of Long Term Evolution (LTE) 4G services later this year. With more antenna connections, AT&T could conceivably offer much better network performance in a much faster time frame, even just by offloading existing users from the crowded existing antenna towers. That may make DAS a savior technology as Ma Bell tries to add more heavy data users to an already crowded cellular infrastructure.

About Paul Kapustka

Paul Kapustka is a longtime journalist who has spent more than two decades covering the information technology business, Paul most recently has been focusing on mobility and how it has changed the computing and collaborative landscape. His newest project outside Mobile Enterprise 360 is a research and analysis operation called WiFi Journal. He is also editor in chief of Mobile Sports Report, which covers the intersection of mobile technology and sports business. Paul is also the founder of Sidecut Reports, a research firm that covered the emergence of 4G technology in the cellular marketplace.


  1. How are they planning to backhaul the DAS antennas?