AT&T: We are deploying 3-channel carrier aggregation on LTE network

Samsung's Galaxy S7 edge is one of the dozens of phones that AT&T said supports its LTE-Advanced service. Source: Samsung

AT&T confirmed to FierceWireless that it too is deploying three-channel carrier aggregation on its LTE network. The news indicates AT&T is joining the rest of the nation’s Tier 1 carriers in deploying the technology.

“We’re currently in the process of deploying 3-way carrier aggregation on our network,” said AT&T spokesman Steven Schwadron. “AT&T started strategically deploying LTE-A in early 2014 and now we cover with LTE-A the vast majority of our customers in our LTE coverage area. We’re also adding also additional spectrum and equipment on an ongoing basis to further boost our network performance.”

Schwadron added that AT&T currently sells 26 devices that are “LTE-A capable,” and that the carrier lists them on its website. Schwadron added that, while LTE-Advanced peak speeds can be significantly higher than LTE speeds, “performance will depend on many factors including location and network traffic.”

Importantly, though, Schwadron declined to provide any further details, including what spectrum bands AT&T is combining through carrier aggregation and where the service is available. He said only that AT&T is deploying the technology into “high-density, high-traffic areas.”

AT&T’s acknowledgement that it is deploying carrier aggregation isn’t much of a surprise. AT&T's John Donovan said in 2014 that the operator would deploy carrier aggregation technology where it can, depending on how much spectrum it has available to meld together. Further, in 2015, AT&T’s Tom Keathley told FierceWireless that AT&T had expanded its use of carrier aggregation to include major markets such as New York, San Francisco and Dallas. 

However, AT&T’s admission that it is deploying three-channel carrier aggregation is noteworthy since much of the industry’s discussion on the topic has so far focused on two-channel carrier aggregation. Carrier aggregation technology allows wireless network operators to essentially glue together transmissions across different spectrum bands in order to provide faster download speeds. For example, AT&T could use the technology to meld transmissions across its 700 MHz and AWS spectrum bands via two-channel carrier aggregation. Three-channel aggregation would add another chuck of spectrum, such as transmissions over PCS spectrum, to the transmission.

Of course, AT&T isn’t alone in deploying three-channel carrier aggregation: Verizon, Sprint and T-Mobile have all said they too are either deploying it or will soon. Sprint last week confirmed to FierceWireless that it launched three-channel carrier aggregation in Chicago and Kansas City, merging transmissions across three different channels of its 2.5 GHz spectrum and providing speeds up to 200 Mbps. And T-Mobile has said it too is already offering three-channel carrier aggregation, though it did not say where.

For its part, Verizon has said it is currently offering two-channel carrier aggregation in the 461 cities, and Verizon’s Mike Haberman said the operator will also offer three-channel carrier aggregation in locations where it has sufficient spectrum.

To be clear, though, three-channel carrier aggregation must be enabled both in the network and on the users’ device.

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Verizon’s Haberman explains 2, 3 channel aggregation: 300 Mbps speeds depend on carrier size, spectrum