Cat1bis HDFDD availability

LTE Cat 1 / Cat 1 bis (Calliope)
1

Hi

From our understanding, adopting Cat1bis in HDFDD configuration would reduce the module cost as well as the overall solution cost, with savings of several dollars when compared to similar solution in FDFDD.

Can you please confirm if Sequans have plans to offer any HDFDD Cat1bis varient of the Calope 2 chipset and modules?"

Thanks

YT

3

Hi YT,

Thank you for your interesting demand.

While the LTE specification does include generic support for HD‑FDD (as defined in 3GPP TS 36.211) independently of the UE category, in practice HD‑FDD has only been implemented for low‑complexity IoT device categories such as Cat‑0 and Cat‑M1. Higher UE categories, including Cat 1 and Cat 1bis, have always been treated by the ecosystem as mainstream full‑duplex FDD (FD‑FDD) devices.

When considering a major product variant such as an HD‑FDD Cat 1bis, it’s important to evaluate not only the technical feasibility (i.e., 3GPP support), but also ecosystem adoption, market demand, and MNO readiness.

Technically, implementing an HD‑FDD Cat 1bis variant would have been possible. However, the ecosystem provided very little incentive:

  • Mobile operators were not supportive: HD‑FDD results in lower spectral efficiency, meaning the same bandwidth yields less usable capacity. From the MNO perspective, this represents spectrum loss.

  • Infrastructure vendors were not motivated either: adding HD‑FDD support to mainstream LTE categories would require significant investment without clear market demand and without investors.

As a result, the market naturally converged on a clean segmentation:

  • Mainstream LTE categories (Cat 1 and above) → Full‑duplex FDD

  • Low‑power IoT categories (Cat‑M1 / NB‑IoT) → Half‑duplex or reduced‑complexity modes

Cat 1bis was introduced simply as a cost‑optimized variant of Cat 1, achieved by removing one receive chain, not as an HD‑FDD alternative.

Given that no MNO or ecosystem player supports HD‑FDD for Cat 1/Cat 1bis, Sequans alone cannot introduce such a variant. Therefore, Sequans Calliope 2 Cat 1bis does not support HD‑FDD, because the market ecosystem does not support it.

We hope this answers to your question.

Best Regards

Imad