In April Qualcomm announced their forthcoming 802.11ac MU-MIMO chipsets. These include the QCA 9990 and QCA 9992 chipsets for business grade access points with 4 and 3 stream radios respectively. Their client device chipsets provide 1 and 2 streams. All these MU-MIMO chipsets provide up to 80 MHz channel width, not 160 MHz. Their highest link speed is then 1.73 Gbps on 4 stream access point and ‘home router’ chipsets, while their client device chipsets with 2 streams have a highest link speed of 867 Mbps. So, for an all Qualcomm setup the upper limits for access points and ‘home routers’ are more usefully considered as aggregate capacity limits, e.g. two 2 stream clients could in theory transfer at 1.73 Gbps. In practice of course it is more likely to be about half of that or less. As these chipsets were “expected to sample in the second quarter of 2014” we can expect them in the products in the second half of 2014, along with some of their competitors – Broadcom and Quantenna have made similar announcements.
With MU-MIMO access points can service multiple stations simultaneously, so the available streams can be more fully utilised. The most important effect of this is to effectively increase the capacity of the spectrum. Obviously this is good news for WLAN owners and managers who have spectrum operating around capacity. Although MU-MIMO does not make a connection faster than before, it does provide more uncontended air time to clients, so they should also feel the benefit as better transfer times.
As MU-MIMO is compute expensive we are going to see more PoE+ equipment. As more channels are available in the 5 GHz band, and they are being added to, it makes sense for access points with two or more radios with omnidirectional antennas to be deployed where spectrum is highly utilised. This will add further to power requirements so we may see a growing market for mid-span PoE+ injectors.
802.11ac and MU-MIMO is coming at a good time as expectations and use of WiFi are soaring; a trend that will continue as the Internet of Things and wearable devices gain traction. If rumours are correct, the ever growing bandwidth needs of static and moving images will soon be added to by the demands of holographic displays. Obviously with all this data aggregating over WiFi to Ethernet we need 10 GbE at a sensible price soon.