"LTE will require ten times more cell locations than 3G, and that can't be done with the existing cost model," he says. "Is base stations get smaller, operators will be looking to acquire sites wherever they can get them, including rooftops, traffic lights and street lamps."
Consequently, Hallwachs says, operators need low-cost installation in a commercially viable site, which means it can't require lots of construction or come with high lease costs. We're seeing distributed base stations with remote radio heads and centralized baseband units, which lowers the footprint. But it's still actively cooled, and you need a shelter for it. What you really need is extremely compact gear with minimal power consumption, passive cooling, and no need for a shelter."
Hallwachs also distinguishes between femtocells - often touted as an offload solution to help cellcos manage spectrum capacity - and carrier-class base stations creating smaller cells. "The sites we're talking about will have to be software upgradeable, support remote management, and other things not associated with femtocells."
They'll also require technologies like SON (self organizing networks) with full automation, and wireless backhaul, says Hallwachs. "Wireless backhaul will be mandatory, but line-of-sight [LOS] wireless backhaul will no longer be feasible in this rollout scenario, so you need non-LOS technology."
Actually getting the base station essentials in pole-mounted form will require squeezing all base station functionality into a single box - something that DesignArt says it's enabling with its SoC (system on a chip) solution, which not only means a smaller form factor, but also one that can run on passive cooling.
"What used to be a roomful of computer equipment now fits in my hand,"he says, holding up a smartphone. "Why can't we do the same with a base station?"
Vendors are already moving in that direction, albeit from different directions. Smaller footprints and passive cooling, for example, has been addressed by vendors developing base stations for rural areas off the main power grid with the aim of making them easier to install without the need for air-conditioned shelters.
Vendors like Alcatel-Lucent are also working towards getting base stations small enough for ad hoc installation, says Philippe Poggianti, Alcatel-Lucent's VP of LTE.
'By 2012, maybe, you will see antenna panels the size of an A3 sheet of paper and around 15cm thick that can be mounted on lampposts,' Poggianti says.