AT&T tests “5G” transmission on mid band (sub 6GHz) and later low band (700MHz) spectrum

AT&T plans to test “5G” transmission  equipment in the 4400 MHz to 5000 MHz band in Austin, Texas, having received an experimental license from the FCC.

The 4400MHz to 5000MHz band is known as the n79 band in 3GPP Release 15 “5G New Radio (NR)” specification [1.]. It is also part of the C-Band in the US.

Note 1.  3GPP completed Release 15 “5G NR” specifications in June 2018. Together with 3GPP final NR specifications in Release 16, they will be submitted for consideration as an IMT 2020 Radio Interface Technology (RIT) at a future ITU-R WP5D meeting.  Release 16 is now scheduled for completion during the first half of 2020.  It will (hopefully) specify ultra low latency, ultra high reliability operation in the data plane- an important use case for 5G/ IMT 2020.


AT&T is running mobile tests between the beginning of June and the beginning of September this year.  AT&T says that those tests will operate “within 20 meters radius of base.”

“AT&T seeks to further validate system design and operation in the sub-6 GHz band for certain applications and use cases such as IAB (Integrated Access and Backhaul), LNC (LTE-NR Coexistence), V2X (Vehicle to vehicle/others), URLLC (Ultra-Reliable Low Latency Communication), mMTC (massive Machine Type Communications), and eMBB (enhanced Mobile BroadBand),” wrote AT&T’s David Wolter in the company’s application for the FCC license.

“We wouldn’t be able to share info beyond that in the license app,” an AT&T spokeswoman told Light Reading.

AT&T is scheduled to start its rollout of 5G on low-band spectrum next year, probably on the 700MHz band.

This week, the company announced a successful sub-6GHz spectrum transmission field test in in Plano, TX. However, the actual frequencies used were not disclosed.

After making our first data transfer over Sub-6GHz spectrum in the field this week, AT&T is a step closer to introducing 5G over sub-6 spectrum, with plans to offer nationwide 5G in the first half of 2020.  This milestone connection was made in Plano, Texas using a Qualcomm Technologies smartphone form factor test device powered by a Qualcomm® Snapdragon™ 5G modem, RF transceiver and RF Front-End (RFFE) solution. Moving this connectivity from the Lab to the field marks significant progress toward our plans to offer 5G to customers across the country. We also remain on track to offer our first smartphone capable of accessing 5G over low-band spectrum as early as this year.

The mega telco and media giant is currently running some of its 5G networks in 21 cities on its 39GHz millimeter wave system for businesses and selected developers. Compared with low-band, these millimeter wave networks offer blazing speeds (1 Gbit/s), but much lower coverage ranges (1,000 to 2,000 feet).  Hence, they will require many more small cells for any given geographical area.

AT&T plans to offer nationwide 5G running on low-band spectrum in the first half of 2020. The operator is expected to use 700MHz spectrum, alongside its FirstNet 4G 700MHz deployment, but could rely on other frequencies as well. AT&T has also been involved in discussions about using the C-Band, largely in the 3.7GHz to 4.2GHz ranges, for 5G.


Addendum: Frequency Bands for IMT 2020

The actual frequencies to be used for IMT 2020 radio aspects (ITU-R WP5D) will be determined at WRC-19 in Egypt this fall.  Those will then be listed in a REVISION OF ITU-R Recommendation
M.1036-5:  Frequency arrangements for implementation of the terrestrial component of International Mobile Telecommunications (IMT) in the bands identified for IMT in the Radio Regulations (RR). 
While nothing has been decided yet, ITU-R has proposed some high band frequencies as per
  19. Question: What frequency bands are under study for the implementation of IMT2020 (5G) RIT/SRITs? 
The following (high) bands, which are already allocated to mobile, will be studied with a view to an IMT-2020 (5G) identification: • 24.25 – 27.5 GHz • 37 – 40.5 GHz • 42.5 – 43.5 GHz • 45.5 – 47 GHz • 47.2 – 50.2 GHz • 50.4 – 52.6 GHz • 66 – 76 GHz • 81 – 86 GHz The following bands will also be studied, although they are not currently globally allocated to the mobile service: • 31.8 – 33.4 GHz • 40.5 – 42.5 GHz  • 47 – 47.2 GHz
The results of the studies will be submitted for decision to the next World Radio Conference (WRC-19), to be held from 28 October to 22 November 2019 in Sharm el-Sheikh, Egypt.  
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4 thoughts on “AT&T tests “5G” transmission on mid band (sub 6GHz) and later low band (700MHz) spectrum

  1. AT&T has not disclosed what frequency band was used for the sub 6Ghz “5G” test. Two emails to Yigal Elbaz, AT&T SVP Wireless Technology, requesting clarification of that and other items were not returned.

    Again, ITU-R Recommendation M.1036-5: Frequency arrangements for implementation of the terrestrial component of International Mobile Telecommunications (IMT) in the bands identified for IMT in the Radio Regulations (RR) will specify what frequencies may be used for IMT 2020 all over the world.

  2. AT&T brought its high-band millimeter-wave 5G network to parts of downtown New York City bringing its launch total to 21 cities, the telecom announced noting that, as in other markets, the service will be limited to business customers. The carrier added that it will expand its 5G coverage to sub-6 GHz frequencies “in the coming months.”

    AT&T has multiple versions of 5G, with 5G+ denoting its super-fast but limited range millimeter-wave flavor. The company also has “sub-6” spectrum that covers wider areas but at slower speeds which it will simply call “5G.” Both of those forms of actual 5G are different than 5GE, the rebranding of AT&T’s improved but existing 4G network that is currently available across the country.

    “As a densely-populated, global business and entertainment hub, New York City stands to benefit greatly from having access to 5G, and we’ve been eager to introduce the service here,” said Amy Kramer, president of AT&T’s New York region, in a statement. “While our initial availability in NYC is a limited introduction at launch, we’re committed to working closely with the City to extend coverage to more neighborhoods throughout the five boroughs.”

    Though limited in range, New York becomes the twenty-first city where AT&T has deployed 5G, extending the company’s early lead in the 5G race over Verizon (nine cities), T-Mobile (six) and Sprint (five). Those rival carriers, however, are letting anyone use their respective networks, not just select businesses or developers.

    It is still unclear when AT&T will make 5G available to everyone, but the company plans to deploy a nationwide 5G network on its wider-ranging “sub-6” spectrum in the “first half of 2020.”

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