According to a recent NPD In-Stat research, by 2015 there will be 160.3 million active small cells, and the retail value of small cell shipments will reach $14 billion. This is because mobile data usage nearly doubles each year, but mobile operators cannot increase expenditures at that rate. At the same time, data rates are affected by the proximity of a device to a cell. Small cells cover areas where macrocells would be overkill and are essential to the success of heterogeneous networking (HetNet).
HetNet is the term used to describe modern cellular infrastructure architecture. HetNet is the practice of integrating small cells, distributed antenna systems (DAS), and Wi-Fi with existing cellular infrastructure to create the best environment for signaling integrity, optimal uplink and downlink capacities, and low latencies.
Small cells include femtocells, picocells, and microcells. Femtocells serve about 4 users and have an effective range of 15-50 meters (typically used in residences and small enterprises). Picocells are used to provide coverage indoors and outdoors for up to 100 users. Microcells are used to support as many as 1,000 users and have an effective range of 2-3 kilometers.
There are currently five methods for powering small cells:
- MIPS cores are being used in residential femtocells, like those made by Broadcom and Cavium.
- SoC vendors are adapting existing mobile processors to meet the needs of femtocells. Qualcomm’s Femtocell Station Modem (FSM) is based on its Snapdragon platform, while Intel, in partnership with Ubiquisys, is developing Edge Cloud local cache processing using Atom cores.
- ARM processors are being used by several SoC providers: DesignArt, Mindspeed, Picochip (acquired by Mindspeed), and Texas Instruments are using ARM processors in combination with DSPs in their chipset designs.
- x86 processors have had limited use in microcells and could become important in picocells. As HSPA and LTE platforms evolve into LTE-Advanced, greater computational power will be needed to process packets and signals over larger spectrum channels, which could be an opening for this architecture.
- IBM’s Power Architecture is an emerging platform in the small cell market; Freescale has been the most vocal proponent.