LTE's flat architecture and fewer handset state changes are designed to reduce signaling compared to HSPA
With the recent flurry of excitement about the possibility of LTE devices from Apple hitting the shelves in a mere matter of weeks, it’s probably a good time to look at the #1 question that we hear from operators on this topic: Will signaling require as much resources and attention in LTE as it has in 3G?
The short answer is: Definitely not! . . . .maybe.
The “Definitely not!” part of the answer comes from the point that LTE is structured quite differently from HSPA, and so LTE signaling is handled differently. LTE has a flat architecture without separate radio network controllers (RNCs), and the number of state transitions (that is, number of steps from Idle to Active in the handset, each of which generates signals) is minimized compared to 3G. These design changes have been specifically planned so that signaling will not cause an issue in the network the way it has for some operators in HSPA. As an industry, we’ve seen what kind of evil knock-on effects uncontrolled signaling can have in 3G, and we’re determined not to see this issue repeat itself in LTE.
However (and this is the “maybe”), it’s important for us to emphasize that we don’t have the end to end LTE smartphone environment in place yet, since by and large, the end device is still missing: LTE smartphones have not yet been produced in bulk. Only when we see how all device manufacturers have used LTE in their handsets can we be completely confident about what level of LTE signaling will be generated. In HSPA, signaling wasn’t an issue at all before handset manufacturers developed Fast Dormancy software that improved battery life while greatly increasing signaling. Likewise, we’ll need to see exactly how LTE smartphones use the network before we’ll be able to give accurate predictions about any LTE signaling volumes.
The good news is that through the Nokia Siemens Networks Smart Labs, we’re working with handset manufacturers to ensure that they understand the issues around the generation of excessive signaling now – not when it’s too late – so we can be reasonably confident that the signaling issues that we’ve seen in HSPA will not be repeated in LTE. And for more good news, in 3G, the most signaling-aware handset manufacturers who have done the most to protect operator networks from massive signaling outbursts are Apple and Nokia. That suggests that any LTE iPhone or iPad wouldn’t be a signaling monster from Day One.
But we can’t give a 100% guarantee until we see those handsets!
This post is by Leslie Shannon from Mobile Broadband Marketing.