Amid all the fanfare over smartphones and tablets, another vast mobile market is undergoing transition. The $40 billion-plus cellular infrastructure segment faces potential disruptions on multiple fronts.
A new class of small basestations in development could reshape the landscape for today’s cellular networks. Indeed, market watchers expect that the vast majority of new basestation installations by 2016 will be some version of small cells.
Meanwhile, China Mobile is driving an initiative in the opposite direction, toward larger pools of basestations that act like data centers. Intel Corp. is backing this move and has its own plans to enter the basestation market next year with a DSP-like co-processor for its Xeon server CP.
From femto to macro
To date, basestations have generally come in one size, placed in sealed outdoor boxes at the foot of antenna towers. These mainframes of the wireless world came under assault a few years ago by so-called femtocells—small, residential terminals that extended coverage generally to individual homes in cell-service dead zones.
Femtocells are on a slow, steady rise as part of next-gen cellular networks. Meanwhile, concepts are emerging to occupy the no-man’s land between the traditional basestation and the femtocell. These so-called small cells would be used by a mix of carriers and private companies, forming a second tier of the wireless network to provide greater capacity in urban areas and extend coverage in rural ones.
Several flavors of small cells are likely to emerge. Concepts for micro-, pico- and metrocells are still evolving. Some will focus on indoor installations to serve relatively low numbers of users who generally will access them while sitting or walking in offices and shops. Others will be more robust for use outside by larger numbers of more mobile users.
|Alcatel-Lucent demonstrated several small cellular basestations at Mobile World Congress, including metrocells linked to a Broadcom reference design to create a small LTE network, left. Carrier Telefonica also used Alca-Lu's small cells in a demo network at MWC.|
All sides agree the basestations will need to support a mix of 3G, Long Term Evolution (LTE, aka 4G) and Wi-Fi networks. They will also have to work seamlessly to hand off traffic to one another and to traditional basestations across all three nets.
Those requirements have dictated software and standards efforts that are still in the works. The 3GPP group, for instance, is hammering out an IP Flow Mobility spec to bring some of the authentication, security and management capabilities of a cellular connection to Wi-Fi links.
Carriers are expected to forge partnerships around small cells, looking to share the hefty costs of building out what amounts to a new tier of their wireless networks. In some cases, they may be forced to share cells mounted on streetlights or in public buildings with other operators, governments or businesses.
Three approaches probably will emerge, said Nick Ilyadis, chief technology officer of Broadcom’s infrastructure group. Some carriers will overlay small cells on their macro basestation networks, connecting small cells and macrocells directly via the IUB control plane protocol for telecom gear. Others will use femtos and macros on separate networks, managed via Internet Protocol links. Still others will adopt the Cloud Radio Access Network (Cloud-RAN or C-RAN) approach being defined by China Mobile.
“They all have pros and cons, and I think we will end up in a world with all three,” said Ilyadis.
That’s a heady reality for the companies that build the basestations.