The MulteFire Alliance announced the completion of its Release 1.1 specification that’s optimized for IoT, adding support for eMTC-U and NB-IoT as well as support for additional spectrum bands.
MulteFire 1.0 was designed to create new wireless networks by operating LTE-based standalone technology in unlicensed or shared spectrum bands. MulteFire 1.1 takes if further by improving on the performance of 1.0 for the global 5 GHz unlicensed band and by adding new capabilities and support for the additional spectrum bands, according to Asimakis Kokkos, chair, Technical Specification Group at the MulteFire Alliance and head of Industry Environment Strategy at Nokia.
One of the enhancements has to do with scheduling. A few short years ago, the Wi-Fi community was very concerned about LTE-Unlicensed (LTE-U) and Licensed Assisted Access (LAA) and how they would manage coexistence with Wi-Fi in unlicensed spectrum. Wi-Fi uses a listen-before-talk (LBT) etiquette that Wi-Fi advocates feared would be challenged by less polite LTE-based technologies.
When you have a dense network with small cells and want to move fast in the IoT world, you might encounter delays in handover with LBT. To solve that, the alliance developed a scheduling system, giving the UE the capability to transmit uplink without having to wait for the base station to tell it to do so.
It offloads the traffic and makes it easier for everybody—“Very simple and very efficient,” Kokkos told FierceWirelessTech.
Currently, there’s a risk of increased uplink delay due to LBT and the need for downlink control signaling in MulteFire deployments. In the new spec, if the UE succeeds LBT within a predefined set of radio resources, it can transmit immediately and it doesn’t suffer from the multiple contentions imposed on scheduled uplink access.
The LTE camp previously claimed the introduction of its new technologies actually helped improve the performance of Wi-Fi, disturbing it less than Wi-Fi disturbs itself. But the more recent changes are on top of that. “In the first release, I think MulteFire was maybe a little bit too kind,” Kokkos said. Now, “it is more fair for MulteFire in this respect.”
The MulteFire Alliance has a technology roadmap aligned with 3GPP 5G standards. The latest enhancements not only provide more robust mobility, faster uplink data and better downlink coverage, they also add additional spectrum bands focusing on IoT, including 1.9 GHz, also known as sXBP in Japan, which is ready for commercial deployment in Japan with support from the XGP Forum and an ecosystem of TD-LTE devices in place that support Band 39. (The 1.9 GHz band in the U.S. is licensed as PCS spectrum.)
The alliance said Release 1.1 will be published to MulteFire Alliance members in January 2019, with public availability by mid-2019. A new white paper, Release 1.1 Technical Overview, provides more details and is available to download.