[Previous entry: "The horror. The horror."] [Next entry: "Spokane really does suck"]

09/20/2004: "Marketing bullspin 101"

Vivato continues its lame attempts to market its way out of the hole.

I just stumbled across this piece of marketing bullshit.

A total of 5 Vivato Wi-Fi Base Stations and 12 Vivato Outdoor AP/Bridges are installed throughout the downtown area to provide wireless connectivity to a 100 block of core downtown area. This core is about a 1.0 mile long an about 0.32 mile wide as designated in Figure 15 by a white outline.

By their own admission, the "Base Stations" are $14,000 each, plus an additional $10,000 in "professional engineering services". The dozen AP/bridge units, taken as a whole don't cost half of what each "basestation" does. Ignoring the AP/Bridge units, someone spent $125,000 to install those 5 "basestations".

Wireless phased array base station installations such as the rooftop deployment, shown in Figure 3, can cost on the order of $14,000 plus an additional $10,000 to install with professional engineering services. Given the efficiencies of this type of equipment, however, a coverage cost of 0.03 to 0.5 cents per square foot is realized. As a result the square mile deployment discussed above can drop to less than $20,000. This investment can be justified again when mobile workforce productivity improvements are taken into account.

My math says there are 27,878,400 sqare feet in a square mile. Vivato claims this deployment is 0.32 square miles, for 8,921,088 square feet of coverage that costs $125,000 to install, not including the 12 Outdoor "AP/Bridges" and their additional "professional engineering". This results in a cost of coverage of $0.0140, or 1.40 cents per square mile, some 2.8X to an incredible 46X the cost of coverage stated earlier in the document. The document goes on to claim:

Again the 5 Wi-Fi Base Stations additionally provide direct access to clients over many square miles around the 100 block city core.

but of course, this coverage is incidental to the goal. Readers of the markeing malarky should consider that additional deliberate coverage will probably cost as much as the original 1/3 square mile did. Assuming that things scale, and that the swtiches don't become an obstacle to each other, each additional square mile will cost in excess of $400,000.

According to the United States Census Bureau, the geographic area of the city of Spokane is approximately 57.8 square miles. If the above cost of coverage holds, it would cost some $23,120,000 in order to completely cover Spokane.

Follow the money. Spokane is only concerned about its parking problems around the Parkade, since they have to pay for it, somehow.

Further, (and back to the technology), such excess coverage may even be harmful to the deployment. 802.11 is based on CSMA/CA, and is therefore required to stop and wait if there is a strong signal being received from any source. Vivato knows this, since its "basestations" have electronics that stop all "beams" on a given channel from sending while any of them is receiving a packet.

It turns out to be impossible to ignore the incoming frames if they're 802.11. Vivato has no ability to filter what is referred to internally as "OBSS" traffic, nor are they likely to ever gain such technology.

If there are 802.11 devices inside the coverage area that aren't part of the Vivato-supplied network, the switch will pend all transmits on the channel(s) where the OBSS traffic exists. A simple extrapolation will show that there are (and will always be) more OBSS traffic than traffic destined for the Vivato switch.

This was the primary factor that drove the "multichannel" fervor inside parts of Vivato. The hope was that by being able to simultaneously operate on multiple channels, the switch wouldn't become blocked. The sad truth is that multichannel operation makes the "basestation" interfere with itself, with mean beam-to-beam inteference of 9dB.

Someone inside Vivato should check the definition of SIR, btw. I'd much rather have 30dB SIR than 0dB SIR (a 0dB SIR would make decoding the signal... difficult) pictured on page 18. I believe they wanted ISR (interference to signal ratio) instead of SIR.