Early this year, T-Mobile identified 1 million square miles where the 600 MHz spectrum is available for deployment and acquired 35 MHz of contiguous uplink spectrum between 663-698 MHz and corresponding 35 MHz of downlink spectrum between 617-652 MHz. They bought the nationwide swath of this spectrum earlier this year for $8 billion and are rolling it out now. They acquired it from 11 TV stations that won reverse auction bids to go off air by 10/25/2017 with 132 stations that decided to share a channel must go off the air by 1/23/2018. This network coverage will cover Wyoming, Southwest and Northeast Oregon, West Texas, Southwest Kansas, the Oklahoma panhandle, Western North Dakota, Maine, Coastal North Carolina, Central Pennsylvania, Central Virginia and Eastern Washington. The idea is to fill in the final gaps in T-Mobile's rural coverage.
In order to support this band, Qualcomm Technologies recently announced new additions to the RF Front-End (RFFE) portfolio that is designed to provide comprehensive support for devices operating in the 600 MHz spectrum. According to their release, the new additions are designed to allow OEMs to rapidly build mobile devices that support new operator deployments of this 600 MHz low-frequency band (Band 71). This spectrum brings greater capacity to mobile operators’ networks, in addition to enhanced outdoor coverage and indoor penetration. Qualcomm Technologies’ solution is expected to enable a wide variety of devices, including smartphones and Internet of Things (IoT) products, to access this spectrum without adding unnecessary complexities to device design and development. T-Mobile is currently deploying network capabilities and Qualcomm® Snapdragon™ Mobile Platform based smartphones supporting 600 MHz Band 71 are commercially available (I believe LG was the first with phones offering this band so a couple are available with more coming).
The new Qualcomm 600 MHz modem-to-antenna solution comprises a suite of RF front end components, including:
- Their first PAMiD, the QPM2622 comes with integrated duplexers, switches and an antenna coupler, and complements the QPM2632 mid-band PAMiD and the QPM2642 high-band PAMiD, for global SKU development.
- The QAT3516 is the first commercially announced aperture tuner optimized for 600 MHz, and comes with adaptive tunability and can be paired with the QAT3550 antenna impedance tuner for advanced adaptive tuning capabilities.
- The High Q Temperature Compensated Filters (HQTCF) process provides optimized performance and the innovative filter design topologies enable challenging specifications including high bandwidth support, low insertion loss and high attenuation to be achieved.
- Extension of support for 600 MHz band B71 in previously announced multimode GaAs power amplifiers QPA4360, QPA4361 and QPA5461.
Around the same time, Qorvo® introduced a line of small-signal products that support the 600 MHz/Band 71. According to the release, this expansion of the company’s infrastructure portfolio makes Qorvo the only supplier to address all frequency bands for 5G communications, from sub-6 through 39 GHz. The new products are linear driver amplifiers that support operation down to 600 MHz–the QPA9805, TQP7M9101, TQP7M9102, TQP7M9103 and TQP7M9105. They complement Qorvo’s already broad range of wireless infrastructure solutions, from linear driver amplifiers and variable gain amplifiers to low noise amplifiers, gain blocks, filters, attenuators, switches and integrated front-end modules. Their release lists the device functions including LNAs, Driver Amps, DVGAs and FEM available and the frequencies the cover.
So we used to refer to cellular frequencies ranging starting at 700 MHz so now need to revise that down to 600 MHz. I sure higher frequencies will be added next extending to even more bands to keep track of including mmWave frequencies in a few years.