Re: How About
Das cow is tasty! My apologies, I should have explained a little more :) For a full barnyard of cellular toys check out
http://scache.vzw.com/dam/news/images/august-2014/VerizonInfographic5%20network%20cave.jpg
DAS is a distributed antenna system. They are typically used in 'mega malls' and sports stadiums. They are pretty much what it sounds like, lots of antennas hooked up to the same system. They use a downward tilt of antenna and a reduction of power to provide a hopefully even service across an entire area (as sticking a single pico cell in the middle of a mall will probably lead to lots of dead areas) and \ or a decent service where there is lots of people by 'densifying' the network. For a given amount of transmission power lower frequency spectrum will travel farther and penetrate walls better, whereas higher frequency spectrum will need a denser network therefore actually give higher capacity. The upside is that whilst there is a maximum transmit power there isn't a rule on the minimum so you can take lower dial spectrum (traditionally in mobile \ cellular land its below 1000MHz) and either reduce the power it works at and \ or tilt the antennas downwards to reduce the area covered, fill in with extra towers and enable it to support more users. A DAS just takes this another step, it reduces power and floods an area with coordinated sets of antennas all tuned to cover a small area without interfering with each other.
Downtilt is great :) What it does is allow you to reduce coverage in certain geographical situations (it's not great if you have tall buildings you want to cover or can't get your antenna high enough) without dialing back on the power so much you start to lose building penetration at the edges.
So back to this fembotcell. Why wouldn't it work in a mall or a sports event. Two different reasons, one in a mall it's limited in how flexible it can be with its antennas. Malls tend to have odd shapes with wings extending out and lots of walls between units. It would work well in a large walmart or home depot but mall of america or the trafford center in England you start to see areas with no signal (probably because your phone got nicked). That and back to capacity. It has decent capacity but when you look at the numbers of people who attend glastonbury etc or go to a large shopping center \ mall We are talking covering close to 100k people. I saw Bowie at glastonbury and I think there was 120k people there that year? Maybe 100k. Barring the tweakers in the dance tent sniffing nail polish pretty much everyone was watching Bowie on the pyramid stage so maybe 70-80k people in a single 5-10 acre field. Football games here, soccer games in England you are looking at 50k plus people. Any normal town with 100k people is likely to have a grid of towers.The island of Maui has around 150k people and about 30 shared towers plus a few extra roof top installations and still has plenty of areas of no signal and capacity issues.
I'm also a little doubtful of how future proof this is as well. Yes it supports carrier aggregation (adding together seperate signals into one signal with a combined capacity, which is large dick waving in all honesty) but does it support 8t8r (8 transmitters, 8 recievers) MIMO (multiple in, multiple out) antennas which boost capacity on the same amount of spectrum (I'm not even going to pretend to fully understand the voodoo behind that one). Spectrum is insanely expensive, so with MIMO, if for a fixed cost you can add extra capacity where you need it most without any auctions etc then thats great. Sprint and Tmobile in the USA are both using this, 4x2 for tmo and 8x8 for Sprint and it is actually delivering the results, far better signal reception at the edge of cells, faster speeds near the middle and lower battery drain.
This femtocell definately has a place, sticking it in the middle of a campsite at glastonbury is a great idea, trying to cover a packed field full of people watcing a stage would probably see it fall over based upon capacity. Using it in a mall it would probably fail on capacity and wall penetration. It's probably better placed in single very large stores.
Biting the hand that feeds IT
