The so-called 4G standard LTE still has major problems with mobility, Research in Motion's senior director of radio standards has said.
Speaking at Mobile Broadband World 2011 in Berlin on Monday, Johanna Dwyer said there was no doubt LTE would have "a large commercial uptake", but "there are a lot of mobility issues that will prove not to be completely solved".
"The first implementations of dongles, laptops and tablets don't really have mobility. Dropping off an LTE cell and re-establishing on another is not handover as such," Dwyer said.
RIM has already implemented LTE in a version of its PlayBook tablet, and a leaked Verizon document had sparked rumours that the upcoming Curve 9370 handset would use LTE.
According to Dwyer, those who launch LTE-capable handsets now run the "risk of alienating customers" who are not satisfied with what they assumed would be true mobility. The result, Dwyer suggested, might be that the customers "move on to competitors that waited a bit longer".
Another problem with LTE is voice, which is a part of the standard that has not yet been finalised. Additionally, LTE networks are only in the process of being built out, so 2G and 3G still have to be built into '4G' handsets.
"Voice for LTE is very immature and you need a [circuit-switched] fallback," Dwyer said.
Dwyer also noted that LTE has not yet proven itself as the cure-all for mobile broadband bandwidth constraints that many have hoped it would be.
"The baseline spectral efficiency gain for the same cell size [and so on] is actually not that big," she said, noting that current releases of the LTE standard were only providing a 1.5x gain over HSPA. With the rate of mobile broadband bandwidth use roughly doubling every year, that "gets eaten up in a few months", she added.
"We're not as far ahead as we thought we were," Dwyer said. "There may always be a data crunch."
ZDNet UK asked Dwyer whether all this meant LTE handsets were not on the near horizon for RIM, but she denied this, saying such devices were "on the horizon".