October 25, 2011 - At the ARM Techcon we had a chance to catch up with Marvell Semiconductor to talk abou their Avastar wireless controllers the 88W8797, 88W8787, 88W8764. As high bandwidth wireless networking extends to more and more devices in the household and SMB, advanced control technology is required. The SoC is targeted at the WAP (wireless access point) and router side of the networking solution and supports 802.11 a/b/g and n protocols, Bluetooth 1,2, and 3.0, and FM transmit and receive.
Figure 1 shows a typical wireless radio environment for today’s homes. These are split between high bandwidth and low bandwidth devices. Functions such as gaming, streaming video, VOIP, and video conferencing are all taxing the performance limits of current single band single antenna systems (1x1) such as 802.11b/g. Connectivity through these WAPs are in two directions - the interface to the WAN for external broadband, which is typically under 10Mbps, and on the LAN side through the router/hub and can exceed 250Mbps. 802.11n supports both single and dual band/antenna systems (up to 2x2). The new specification for 802.11ac which is comming to market in late 2012/early 2013 supports up to 4x4 systems.
Typical Wireless home broadcast configuration
The new SoC from Marvell addresses this market by bringing the advanced MIMO (multiple input and multiple output) technologies with the enhancement of beamforming for high coverage bandwidth and distance improvement. These technologies are in place across the technology space in the part, and bring automated control to the products supporting both legacy and new products. The beamforming works by performing active phase balancing per channel for each of the channels in the MIMO system. This broadcast and receive are performed independent of the end point device and independent of single or dual antenna transmit or receive systems.
The part supports both explicit beamforming (both the transmit and receive side have the technology) and implicit beamforming (the WAP is upgraded and there is no chipset upgrade on the wireless end point side). This technology showed no major differences at 15 to 60 feet from the WAP. However, up through 100-130ft from the WAP, the new implicit system still provided over 80Mbps where there was no connection previously. In addition to the increased connection power, the technology helps compensate for standard signal blocking obstructions in a home. The antenna placement and orientation sensitivity is dramatically reduces the phase variation in all directions including vertical. Without beamforming, most antenna systems broadcast in a dominant plane, which requires multiple WAPs to address multi-floor buildings. This allows for full spherical broadcast bringing flexibility to the placement of both the WAP and endponts (TVs, game consoles, IOT sensors, mobile devices).
The SoCs are supported by a software management applications that allows for web based central administration and provisions for the WAPs and end point devices using this technology. The current suite of parts supports both the 2.4GHz and 5GHz WiFi spectrum standards and is compatible with the beamforming specification that is part of the 802.11ac protocol.