Yes, low-band 5G can be combined with mid-band and high-band spectrums using a technique called carrier aggregation to improve network performance[4][7][10].
How Combining Bands Improves Performance
* Increased capacity and efficiency Combining mid-band spectrum with low-band spectrum leads to better network capacity and efficiency[7].
* Coverage extension Inter-band carrier aggregation enables the combination of high-capacity downlinks in the mid-band spectrum with an uplink in the low-band to extend the mid-band coverage by up to 30 percent in suburban and rural areas[10]. Combining 5G high-band with low-band FDD can increase the high-band cell coverage area more than threefold and improve in-building performance in urban areas[10].
* Enhanced data speeds Combining low- and mid-band spectrum delivers significant improvements over the average 4G/5G downlink speeds[10]. Combining frequency channels increases bandwidth, which results in more data and faster speeds[1].
* Cost-effective deployment Available low-frequency bands may be exploited for LTE/NR uplink spectrum sharing in combination with NR on the C-band to allow operators to ensure faster and more cost-effective deployment of C-band[5].
* Addresses capacity demands Combining low-band with mid-band can help meet the demand for capacity beyond the reach of mid-bands, especially for deep indoor spaces[3].
Low-band 5G provides extensive coverage, while mid-band offers a balance between coverage and speed, and high-band delivers fast speeds with limited coverage[4]. Combining these bands allows 5G to optimize performance and enhance coverage and reliability[4].
Citations:
[1] https://www.wilsonpro.com/blog/what-is-5g-low-band
[2] https://nybsys.com/5g-bands/
[3] https://www.gsma.com/connectivity-for-good/spectrum/wp-content/uploads/2022/07/5G-Low-Band-Spectrum-1.pdf
[4] https://dgtlinfra.com/5g-spectrum-explained/
[5] https://www-file.huawei.com/-/media/CORPORATE/PDF/public-policy/public_policy_position_5g_spectrum.pdf
[6] https://www.ericsson.com/en/blog/2021/6/what-why-how-5g-carrier-aggregation
[7] https://www.reply.com/en/telco-and-media/understanding-5g-spectrum-frequency-bands
[8] https://www.telecomhall.net/t/what-is-the-technical-challenge-in-having-low-band-5g-nr-lte-simultaneously/10507
[9] https://www.westbase.io/what-is-low-mid-and-high-band-the-5g-spectrum-layers-explained/
[10] https://www.ericsson.com/en/reports-and-papers/mobility-report/articles/t-mobile-5g-spectrum