Ericsson dismissed suggestions it is locked in an IP dispute with Huawei over NB-IoT, as well as talk of standards bifurcation. It also blamed ongoing standardization activities for the chatter about interoperability problems.
Eric Parsons, Ericsson's head of 4G and RAN mobile broadband at its business area networks division, says the 3GPP made some "corrections" to the NB-IoT standard as recently as March.
"It is very atypical of the 3GPP to introduce late-stage scenarios that lead to incompatibility," he tells Light Reading. "There might be a period where the whole ecosystem is catching up with this last round of changes in the specifications. That is perhaps the seed for what you might have heard regarding compatibility."
During a subsequent email exchange with Ericsson, Parsons said the use of the word "atypical" was "probably incorrect."
"A required non-backward-compatible change was introduced, but it was with the understanding that this was ahead of any widespread technology rollout and therefore quite OK," he said. "Of course, test activities have to be aligned as to which 3GPP release to use in this circumstance."
The 3GPP did not respond to requests for a comment on these "late-stage" changes to the NB-IoT standard.
Parsons also said in Ericsson's email that he had "no knowledge of any long-standing interoperability issue."
"We have been conducting tests in customer labs now for quite some time without any such issue emerging," he said. "Otherwise we are not aware of any issues and our customers have not raised any issues."
Huawei indicated that it was not aware of any interoperability problems with Ericsson while declining to comment on the recent changes to the NB-IoT standard.
But Nick Hunn, the chief technology officer of consulting firm WiFore, has argued that interoperability problems are deep-rooted.
In a blog published in December, Hunn said the telecom industry has split into two camps on NB-IoT, with Ericsson and Nokia pursuing an approach that remains "incompatible" with that taken by Huawei and Vodafone.
According to Hunn, the approach taken by Ericsson and Nokia "is essentially a cut down, lower power variant of 4G." That taken by Huawei, he says, is more of a "clean sheet" approach that owes much to the Weightless standard developed by Neul, a UK firm that Huawei acquired in 2014. (See Huawei Spends $25M on Neul's IoT Smarts.)
Hunn describes the 3GPP's efforts to resolve differences between these approaches in its specifications as a "fudge."
"Vodafone is using Huawei's NB-IoT, which is totally different from the Nokia NB-IoT which [Finnish operator] Sonera is using," he writes. "To survive, NB-IoT needs to be a single, low cost, globally interoperable standard. In its current form, NB-IoT is dead."
Next page: LTE-M looms