The Chips are Ready

Mobile operators would like to deploy small cells, but their reaction to some of the early products has been lukewarm. Picocells that are simply low-power versions of a high-performance macrocell are far too expensive. Femtocells designed for autonomous consumer use are suited to a coverage application, and do not play well in a dense urban network. Small cells mounted on a streetlight need expensive backhaul, which is generally not available.

These negatives are beginning to evaporate.

Recently, several SoC suppliers have introduced multi-core processors which are highly suited to work as a “base station on a chip”. The level of integration is awesome, with dozens of processor cores operating at high speed, with programmable DSP elements and hardware accelerators to handle high-speed computation while remaining very flexible.

The multi-core architecture is the key to success now. Simple reliance on Moore’s law to increase speed continuously is not enough: to make a small cell work, dozens of operations need to take place simultaneously, and each processor core must be suited to the tasks assigned. Several IC suppliers have recognized this need, resulting in strong products from Texas Instruments, Freescale, Mindspeed, Cavium, Picochip, Broadcom, and others. Each company has its strengths, but all of these “Base Station on a Chip” products utilizes a large number of high-performance processor cores and an internal interconnection fabric. Many of these alternatives can run the software from traditional macrocell or microcell products, making the integration with the macro network much easier.

The existence of 5-6 strong IC alternatives on the market will drive cost down quickly, and mobile operators will quickly start to see product offerings at acceptable cost levels….a few thousand dollars for a high-performance picocell or carrier femtocell.

The next question will quickly arise: What about backhaul? Depending on the capacity and bandwidth involved, some of the new ICs on the market can actually handle baseband processing for both radio access and backhaul….taking a major expense out of the equation. Mobile Experts is predicting a future where the “Base Station on a Chip” handles both datastreams, with RF transceivers branching in multiple directions. The result: Inexpensive, highly integrated small cells with multiple antennas, which can be deployed easily with licensed LTE operation to end users, and licensed TDD OFDM backhaul. The chips are coming together. Mobile operators need to start getting their backhaul spectrum licenses in order.