The MulteFire Alliance was formed in December 2015 with founding members Nokia and Qualcomm, joined by Ericsson and Intel, to promote MulteFire as an LTE-based technology for small cells operating in unlicensed and shared spectrum. The alliance has since grown to include close to 30 members.
Now, "the MulteFire Alliance is adapting LTE IoT to operate in the unlicensed spectrum to expand beyond mobile broadband and high-performance IoT supported by MulteFire 1.0,” wrote Hao Xu, principal engineer/manager at Qualcomm, in a blog post. “This will in turn bring new opportunities for private LTE networks and enable LPWA (low-power wide-area) use cases, leveraging narrowband LTE IoT technology."
Qualcomm hasn’t announced a product or the timing of any product related to the MulteFire announcement. But it surely will mean more competition for entities supporting LoRa, which uses the 900 MHz ISM band, and for Sigfox, which also is building out LPWA network technology using unlicensed spectrum.
In the U.S., Verizon was the first to announce a nationwide LTE Category M1 network for IoT applications. About seven weeks later, AT&T announced the launch of its nationwide LTE-M network. Expectations are high that U.S. operators will launch another standards-based IoT technology, Narrowband IoT, or NB-IoT, but AT&T has said it’s still evaluating that.
Sprint announced in May that it will complete its deployment of LTE Cat 1 technology across its nationwide network by the end of July 2017 and plans to begin deploying LTE Cat M in mid-2018 followed by LTE Cat NB1. T-Mobile CTO Neville Ray tweeted in March that his company is focused on NB-IoT and plans to support it in 2018.
NB-IoT is being rolled out in other parts of the world already. Telenor Norway, for example, has been running an NB-IoT smart parking pilot with Norwegian-based ITS-provider Q-Free since January.
The technology associated with LTE Cat M1, enhanced machine-type communication, or eMTC, also was defined in 3GPP’s Release 13 and is generally considered a higher performance standard with voice and mobility support.
Both Cat M1 and NB-IoT are two-way in that there is an uplink and downlink, and Cat M1 supports half duplex just like NB-IoT does, but it also supports full duplex, which is an LTE way of doing uplink and downlink simultaneously, according to Danny Tseng, staff manager, technical marketing at Qualcomm.
If an operator has deployed Cat M1, why does it need NB-IoT? “We really see Cat M1 and Cat NB1 as being complementary,” Tseng said. “There’s certainly some overlap in use cases, but there’s a pretty good distinction between the two.” For example, if you have a device that requires voice or an asset tracker that needs mobility with handover, you would use Cat M1.
On the flip side, if you’re deploying agriculture sensors sitting in the field, some of which require long-range coverage, and you need it to be as simple as possible, you can support it on Cat NB1. Some customers have a range that requires Cat M1 and other sets that need NB1, so in that sense they’re complementary, he said.
The fact that others are exploring ways to adopt NB-IoT to work over ISM bands is a welcome development to some supporters of the rival LoRa technology.
“It is one more proof that use of unlicensed frequencies is not only feasible but also very valuable for low-cost and scalable IoT networks,” said Alper Yegin, co-chair of the Technical Committee in the LoRa Alliance, in a statement provided to FierceWirelessTech. “On the other hand, having super-efficient over-the-air protocols is a key success factor due to usage constraints stemming from regulatory rules on these bands. Using protocols that are designed ground-up with these constraints in mind is essential as [what is] being done by the LoRa Alliance. And that is where the next challenge is awaiting 3GPP when they continue trimming their legacy complex protocols stacks to fit the new use.”