LSI looks to power mobile networks with ARM-based processors

IDG News Service - Chipmaker LSI is taking ARM-based processors to new frontiers with its upcoming AXM5500 family, which will be used in mobile base stations of all sizes.

From today's smartphones, tablets and thin clients to tomorrow's servers, ARM-based processors are powering a growing number of different devices, and if LSI is successful, mobile networks will be added to that list. The company's AXM5500 family of processors will use up to 16 Cortex-A15 cores to power base stations for mobile networks.

The Cortex-A15 is ARM's most powerful processor to date, and is used in products like the Nexus 10 tablet from Google and Samsung Electronics.

"The intention is to provide high-performance and good efficiency on a scalable platform," said Troy Bailey, director of marketing at LSI.

LSI's processors for wireless infrastructure have historically been based on PowerPC processors, but because of increased demand for different size base stations in so-called heterogeneous networks, it decided to add ARM-based products.

In addition to achieving a new level of efficiency, working with ARM allows LSI to build a processor family that can be used in anything from a macro cell down to a pico cell, which means lower development costs, because software can be reused, according to Bailey. Pico cells are used to provide coverage for areas such as offices and shops. Installation and management becomes easier, as well, Bailey said.

The first two products are AXM5516 and AXM 5512, which have 16 and 12 cores, respectively. They are intended for use is large base stations. LSI will in the future add processors with fewer cores that are a better fit for small cells.

The product family also uses ARM's new CoreLink CCN-504 Cache Coherent Network interconnect, which was announced in October last year. It can prioritize time-sensitive traffic and offers up to one terabit of usable system bandwidth per second, according to ARM.

"It is a very good and scalable interconnect. One of the challenges when building high core count processors is making sure you have no bottlenecks and waste the cores," Bailey said.

The company is also looking at ARM's new big.LITTLE processing architecture, which in its first generation combines the powerful Cortex-A15 and the energy-efficient Cortex-A7 on one die.

"There certainly are some tasks that need a very strong single thread performance, and there are some tasks that don't, and it doesn't make sense to light up a big A15 if it can be done on an A7, so we think it makes sense," Bailey said.

The company will start sampling the first processors during the third quarter. Because the products aren't being sampled yet, LSI will have to make to with visual demos showing the performance and power savings at next week's Mobile World Congress.

LSI will have to convince equipment vendors that using ARM in their base stations is a good move and at least one company is open to the idea. Ericsson isn't currently using ARM-based processors in its base stations. But "as we continue to expand and develop our base station portfolio, we always evaluate what possibilities are available from the general ICT industry and we might use ARM based processors in the future," a spokeswoman said via email.

"We definitely have some major customers that are going in the ARM direction, and we have built this product for them" Bailey said.

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