As for diversity, there are several implementations of it and not everybody was using a true diversity design. That was the same with the use of the term “mesh”. Too many different implementations and feature differences. Depending on the type and processor overheard, diversity simply makes up for a lower quality antenna design. 8? apart doesn’t really make a huge difference in the signal quality unless the antenna has flat spots in radiation pattern that were signficant. Again, this supports the position I took earlier. $2000-$3000 for the radio, $30 for the antenna. Kind of like putting bicycle tires on a Drag Race Car. You can make all 800 horsepower but if you can’t get it to the ground to convert it into forward momentum, it’s sort of useless.

There is no doubt that 802.11n is better than 802.11b/g technically. However, your statement about decreasing the cost is completely dependent on the premise that a $1500 802.11n will allow a reduced number of AP’s compared to standard 802.11g. I still point out that you can deploy 3-5 802.11b/g AP’s for every 802.11n AP. Of course, I don’t have all the rules and costs your big cities in the East have which the cost of the AP superfluous as a percentage of the total package, but just at the unit cost, will an 802.11n AP cover the same area as 3 802.11b/g AP’s for the same omni-directional antenna gain?

As for diversity, there are several implementations of it and not everybody was using a true diversity design. That was the same with the use of the term “mesh”. Too many different implementations and feature differences. Depending on the type and processor overheard, diversity simply makes up for a lower quality antenna design. 8″ apart doesn’t really make a huge difference in the signal quality unless the antenna has flat spots in radiation pattern that were signficant. Again, this supports the position I took earlier. $2000-$3000 for the radio, $30 for the antenna. Kind of like putting bicycle tires on a Drag Race Car. You can make all 800 horsepower but if you can’t get it to the ground to convert it into forward momentum, it’s sort of useless.

There is no doubt that 802.11n is better than 802.11b/g technically. However, your statement about decreasing the cost is completely dependent on the premise that a $1500 802.11n will allow a reduced number of AP’s compared to standard 802.11g. I still point out that you can deploy 3-5 802.11b/g AP’s for every 802.11n AP. Of course, I don’t have all the rules and costs your big cities in the East have which the cost of the AP superfluous as a percentage of the total package, but just at the unit cost, will an 802.11n AP cover the same area as 3 802.11b/g AP’s for the same omni-directional antenna gain?

Almost ALL deployed WiFi networks do not even use diversity!

What we will find is that the new generation of .11n muni capable APs will cost no more and likely less than the current generation of less than capable .11g APs.

.11n will not only INCREASE the quality of the coverage but DECREASE the cost.

We MEASURED 802.11n clients and APs IN THE WILD – in the presence of other .11g products and as compared to other .11g products.

Put a traffic sniffer on any outdoor .11g products and what you will often see is HUGE link level retry rates. I have seen 1000% retry rates on client uplinks for .11b/g products AND 150% retry rates for downlinks.

When using .11n, these retry rates drop dramatically. And further, .11n units seen to do a better job in deciding the right modulation rate that legacy .11b/g units.

The effect of .11n then .. is to dramatically DECREASE interference by more efficient use of the airwaves.

This is simply not speculation and opinion .. this is MEASUREMENT.

1) No argument. However the gain in performance will only be achieved when there are no other 802.11b/g anything around that create interference and everyone has 802.11n on their laptops. That isn’t going to happen for many, many years. For good or bad, we are stuck with 802.11b/g and that’s what we need to make work right now.

2) I agree that Meraki’s equipment is inexpensive as long as you use their authentication model. This may have changed but I haven’t followed them for a while. However, nobody cares if it’s mesh and we have a 2 radio model that costs less than half that with a signficantly larger coverage area that compensates for fade resistance with better RF engineering and overlap design.
3) I doubt that the new technologies will be successful in the short term since very few cities are purchasing anything anyway.

As Bubba said, 802.11n hasn’t shown it can play nice with others yet. It was supposed to be compatible but instead it’s a random noise generator that basically escalates the battle in terms of interference. If I’m in IT and my 802.11 network goes down in my office becase some 802.11n AP was installed outside my window, I would probably make sure that AP never sees another radio it can connect to until it came off the pole.

Until the world all goes 802.11n, it’s going to be a red herring and with 802.11a/b/g equipment coming down to less than $100, it’s difficult to cost justify 802.11n just yet.

1. In a multipath environment – 802.11n APs will deliver superior coverage and performance to legacy .11g clients outdoors. They will service more types of client cards over a greater area. This is simple test results we and other folks have done.

2. In many applications, performance is simply not the issue. In which case cost of coverage is dominant issue. Leaving aside the issue of particular vendors for the moment – when we can drop the cost of a 2 radio mesh to $500/radio (as Meraki has done) AND use 802.11n for improved fade resistance to improve the quality of coverage to legacy clients – this is substantially less than any other commercial mesh vendor and sets a new standard for the cost of coverage. Our tests of 802.11n AP clearly demonstrates this.

And frankly, since penetrating fiberglass RV shells is a multipath environment, if effective “indoor” coverage is a design goal – 802.11n will in fact improve that coverage rather dramatically. The 30% improvement in cost might be a minimal investment over a fourth future wireless network.

While not always compelling, the ability of .11n to increase coverage also means decreasing the number of hops in a mesh. And since mesh performance decreases exponentially with the number of hops – even 2 or 3 hops will make a cable connection look like dial-up and be effectively unusable.

3. 4G/LTE/700 MHz/WiMax … are all interesting possibilities but all have their own challenges. When deployed on licensed bands we will see DSL-like performance at 3x DSL prices, and there are only few frequencies available for un or lightly licensed deployment of WiMax devices. The price points for these “private” WiMax systems argue for applications with wide area coverage with a modest user load. WiFi will likely always be the appropriate choice for enterprises, campuses, MBU and in many cases municipalities.

4. Individual vendor products always reserve the right to do it wrong.

If want to see for your put three off the shelf N AP’s within a few hundred feet of each other. (Real world stuff not some controlled lab test with 200 Mw card)
Now fire up your Wi-Fi sniffer, see all the noise??
Now shut down the N AP’s, Gee what happened to the noise?

As we can not control “the other guy” we must control ourselves.

I use the older Meraki units, they work great. I would never try to cover any amount of space without Mesh networking, it just makes sense to me to use mesh.
In fact I am consulting on a RV park setup at this time, they are deploying 16 plus Meraki single radio units over 7 acres, the cost of the gear plus mounting gear is less than $ 6000.00 total for park owner.
We have two 8 meg down 2 meg up cable modem connections to share between 30 or so concurrent connections at peak times. The only reason I am going with such a high AP density is the park has had three other wireless networks which have all failed to provide coverage inside the RV’s across the whole park. The owner wants 100 % coverage in his park, I figured I may bake a few brains but they will have internet as they get nuked.

If I used the lowest cost N AP from Meraki it would have increased the job cost 1/3 or more and as most users have b/g cards and even the ones with N cards will default to g/b at 30 feet or so, we would spend more and have less.

Now remember in most cases the network bottle neck is the Internet connection not the traffic between client and AP’s (well not in well designed network anyway). One of the first things I do on any “public” network is to choke the end user bandwidth down to 1024/256 so more users can have better internet, so why do I care about the speed to the end user to the backbone?? If they are getting more than the allowed Inet pipe it does them no good.

The Wi-Fi world is at a turning point, within two years we will see a new set of 4G AWS / 700 MHz / Wi-Max client devices built in most laptops / desktops.
I tested the older single radio Meraki mesh devices for over a year before I felt we could deploy them in the field, I will hold out until I can test one of the 4G systems.

As for “beam steering, spatial diversity and MRC:” As you yourself note, Ken, none of these work at long distances. But the interference from 802.11n systems can propagate for miles, harming efforts to deploy broadband to unserved areas. And so do mesh networks, which can make spectrum totally unusable by other systems.

Municipal wireless networks are, to put it simply, a bad idea. They waste spectrum, have poor coverage (especially inside buildings), and at the same time harm privately deployed systems. Greater interference from 802.11n would make matters even worse. The government should not compete with private business — and especially should not DISABLE private businesses by hogging the spectrum. Private enterprise can do the job better. We are, and we’re proud of it.

Meraki’s new 802.11n outdoor mesh product dramatically lowers the cost of deployment. Read my article: http://www.muniwireless.com/2009/02/24/meraki-releases-80211n-mesh-product/

They are selling their 802.11n mesh nodes for $1500 list price. That price is about half to less than half of what the other vendors are offering.