Chips target unified edge switch for wireless, wired clients

Broadcom this week announced new chips designed to create a low-cost 802.11n wireless LAN edge for the enterprise, without the need for separate WLAN controllers.

The two highly integrated chips are designed for 11n access points that will cost about the same as today's enterprise 11a/b/g devices, and for an edge switch that can handle both wireless and wired clients, eliminating the conventional controller-based architecture that is the foundation of most WLANs today.

This trend toward a unified edge switch for wireless and wired clients has been talked about for more than two years but has gained little traction. The development was sparked by emerging silicon products from Broadcom, SiNett and Marvel, and by software from NextHop (since acquired by U4EA). D-Link introduced a unified edge switch in May 2008 based on the NextHop code running on Marvel chips.

The premise is that by collapsing separate wired and wireless networks into one at the edge, enterprise IT gains by simplifying network deployments, operations and management, and by lowering both capital costs and total cost of ownership.

The new Broadcom chips come at time when two key developments are intersecting. First, 802.11n, with 300Mbps data rates per radio, is moving into large-scale enterprise deployments, offering 5- to 8-times the throughput of 802.11b/g networks. Second, some enterprises that have deployed wall-to-wall WLANs are now discovering that most of their existing -- and expensive -- wired ports are lying idle, as end users rely almost completely on the WLAN for network access. This trend is triggering intense debate, as the reader comments about our recent story on this trend make clear.

Broadcom's BCM4748 chip supports a 2x2 MIMO configuration for 802.11n access points, using the 2.4 and 5 GHz bands, and running with standard 802.3af power over Ethernet. It's designed as a "system on a chip" and integrates all the 802.11n components, along with Broadcom's enhancements to create a more robust signal, with the latest MIPS32 533MHz processing core, a 10/100/1000 Ethernet MAC controller, on-board SRAM, 802.1x and WPA and WPA2 for enterprise-class security, USB 2.0 host ports, and power amplifiers.

Using the new chip, manufacturers can slash the overall bill-of-material costs by 30% to 35%, says Michael Powell, senior product line manger for Broadcom's enterprise switching group. "What we're really look at are [final] cost points for dual-concurrent 11n access points that are similar to those for dual-concurrent, enterprise 11a/b/g access points today," he says. He cites market research data as putting those list prices in the $300 to 400 range, with comparable 11n access points considerably more expensive.

The new unified switch silicon is the BCM56520, which supports CAPWAP tunneling to attached WLAN access points, and up to 28 Gigabit Ethernet ports, or 24 such ports and four Broadcom HiGig ports (which support Broadcom's protocol for high-capacity interconnections with other Broadcom systems). It's about the same price as the previous chip but with far greater capacity to handle 11n data rates, according to Powell.

The package also includes the latest version of Broadcom's FastPath Unified Wireless Switching systems software.

The products are sampling now with equipment makers, who could introduce access points and switches based on them by the end of 2009 and into 2010.

This story, "Chips target unified edge switch for wireless, wired clients" was originally published by Network World.

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