Femtocells support mobile phones in developing nations

Subscriptions to “old generation” 2G GSM-based mobile phone networks are growing significantly in emerging mobile markets such as India and Africa.

As a result, a couple of UK-based companies have seen an opportunity for a wireless basestation platform supporting the latest cost-effective femtocell architecture which retains compatibility with existing GSM basestations

The issue is that many new generation basestations do not offer 2G GSM capabilities, focusing as they do on the broadband-enabled mobile technologies like 3G and Wimax.

“This is widening the so called digital divide, and creates a barrier to adoption by the vast majority of the existing GSM user base,” said Cambridge Consultants Limited (CCL).

The company has produced a GSM/GPRS/EDGE/E-EDGE physical layer (PHY) reference design called Centaur implemented on a chipset designed by Bath-based picoChip.

“Femtocell development to date has focused on 3G and 4G technologies, but this product dramatically extends that, enabling low-cost basestations and femtocells for the high-volume GSM market,” said Nigel Toon, president and CEO at ­picoChip.

CCL demonstrated the Centaur reference design at the CTIA Wireless 2009 event in Las Vegas earlier this month.

The aim is to offer designers next-generation basestations and femtocells that incorporate 2G and 2.75G capability. This will allow them to develop low-cost basestations for developing markets such as Africa and India.

According to the Global Mobile Suppliers Association, much of the recent growth in GSM subscriptions is in the developing world.

By the end of 2008, there were 365 million GSM subscriptions in ­Africa, 100 million of whom had joined that year.

In 2008, India saw a 47.5% growth in GSM subscriptions, rising by an average of 6.83 million subscriptions each month, from 170 million to more than 250 million.

“GSM will still be in operation for many years, if not decades, to come, delivering the services required by billions of subscribers,” said Tim Fowler, commercial director at Cambridge Consultants’ wireless division.

“It is critical that the deployment of mobile infrastructure includes GSM capability. One of the challenges for the developing world in ­particular is the cost of infrastructure.”

The reference design addresses the cost issue by including a complete framework model and code implemented on the pico­Array from picoChip.

"The technology can be used for GSM-only femtocells, for example for low-power GSM licensees,” said Toon. “It can also be used for dual-mode WCDMA/GSM femtocells, or even as a low-cost macrocell for economical wide area coverage in rural areas or developing countries.”

PicoChip has a range of femtocell chips developed with a series of partners. At one end is the PC8219 baseband chipset for eight-user HSPA femtocells designed to run on its PC202-10 processor chip. At the other end is the PC302 aimed at more cost-sensitive residential applications.

“Small cells are a crucial part of networks in the future, and we have shown that our approach can be extended to both 2G and 4G,” said Toon.

Source: electronicsweekly.com