From a healthcare perspective (via any vertical market) the hospital is the worst multi-path environment available. This multipath environment is caused by all the reflective elements present such as steel carts, beds, fluids, and tile/reflective surfaces, plus everybody moving around 24/7/365. Add to this all the movement and mobility that is constantly going on as described. Not a good environment for a RF signal to play in..period. Example your smart phone in the depths of building. This is bad for the performance of 802.11a/b/g, but actually is an advantage for 802.11n. Understand that MIMO with 802.11n, takes advantage of multi-path. So then how has the site survey changed and what is the true throughput of 802.11n? The traditional site survey (for WLAN) plans for the performance of negating multi-path with 802.11a/b/g, but this will degrade the potential performance of 802.11n, thus decreasing available network throughput. This requires a careful thought process "and" site survey on how to balance both what is somewhat considered legacy WIFI (802.11a/b/g)with 802.11n. (Let me say that 802.11a/b/g is not legacy, but the IT mindset is focused on speed...more better) Just remember it is not always about speed, but for the application to perform in the correct defined business model. In this case a lot of medical device applications with 802.11a/b/g work extremely well. Add to this, not many if limited OEM embedded 802.11n modules are offered today. This will mature, just like 802.11b to 802.11a/b/g, and 802.11n, once power mangement issues are resolved regarding MIMO. (It takes a lot of power to transmit and receive). Sorry it is physics.
Beamforming is a great "marketing term", sounds like something dreamed on a napkin over a few bottles of beer or glasses of wine, but in fact it is pretty simple and has been around the the wireless world for a long time. Beamforming is pretty straight forward. It is method of directing RF energy in order to improve the signal to noise ratio (SNR) at the receiver, thus improving the reliability of the signal. When you have more antenna elements (dynamic beamforming) to select a signal in an x/y/z axis you then can use software and algorithms to clean up the signal relative to the noise floor and then send back this signal in phase using the same antenna elements. So, what does this all mean? OK, Cisco uses 'beamforming", and also Ruckus Wireless. I go back to my old days of "digital radio receivers". If you use 14 to 3 antenna elements you tend to receive a better S/N of which is based upon all the same output of the transmitter and received receiver. It also probably overcomes a lot of the noise floor issues, since you have more antenna elements to receive and thus transmit. Thus the algorithms can clean up the signal... in fact have a "cleaner signal", to transmit back. Being able to look at the RF signal in a 3D axis, i.e. x/y/z, will in addition provide the value add of discerning the holistic environment from an actual multi-path and real life(demonstrated) RF performance venue provides major league value to ensure the ultimate network throughput. 802.11n is (each end point entity), wlll need to evaluate whether DAS can fit within a financial or technical within this broadband model..Enough said. Just look to those business models that tried a go at this! It is my opinion that RF performance not only needs to be looked at from the network valuation; but how the RF design will utimately impact the back end network "performance" model. While it is known that players like www.ruckuswireless.com have little footprint (at least in healthcare), their technology and performance just makes it seems some of a technical and financial sense against the yeah what network dudes consider. www.cisco.com. (I am not biased but just reading the performance RF models, of the leading network wireless performance modeling...leave it at that!) However RF is very complex and the more and more push to the RF envelope making it 100% 24/7/365 simply means better and confirmed absolute performance. Cisco Systems (while I got to digress they did not get where they are with not a lot of brilliant people), it just holds that a lot of smaller players with innovative technologies are nipping at their ankles). Heck, just think of Apple versus Microsoft! They the global leader in networking www.cisco.com tend to inovate by past experience via acquisition when competition threatens; so stayed tuned to the next venue of the next stage of wireless..it will be very interesing. They (Cisco Systems) will and have always kept their eye on the ball of technology innovation. Who is the next target for acquistion?