| Wireless Density Factor |
Click On Chart For Expanded View
Wireless Density Factor (WDF) is a measure of the number of RF transmitters per unit area, or conversly, the area expected for a single transmitter. The plot of the WDF of time shows an exponential increase in the number of transmitters. The growth rate shows a doubling in the density every 18 months since the first RF transmitter shortly before 1900 when Marconi began sending wireless messages.
Included in the count of transmiters are strictly active RF transmitters, excluding RFID tags. Also not included are Infra-red or other optical transmitters.
This particular chart shows the density for a typical medium size city. Larger cities would have the the plot line shifted up while smaller cities, urban areas and remote areas would have the plot line shifted down. Regardless, the density is doubling every 18 months and this will not stop.
Today, in 2007, in such a medium sized city, we are at a density level of 1 transmitter every 4 square meters on average or 250,000 transmitters per square kilometer.
There are two 'Conjecture' points that deserve some attention on the chart
The first is the "Wireless Mesh Conjecture" where the density of wireless transmitters reaches a level that allows a seamless mesh for communication. This is projected for 2010 when we reach 1,000,000 transmitters per square kilometer or 1 transmitter per square meter. These density levels will allow for signal hopping from one device to another until a high-speed channel sends the digital data to it's intended destimation. This wireless mesh closes the "last mile" of connectivity using common devices either in our pockets, are cars or simply placed on telephone poles (oddly enough). The devices will need more sophistication than RF transmitters generally carried today. They will need to be multi-frequency capable and more inportantly, be able to provide multiple transmissions simultaneously. This will not be difficult in 2010. What will be difficult is getting the standards in place that enable the communication from one device to another at the levels necessary.
The other conjecture is the "Human Flesh Conjecture". There becomes a wireless density level so high that RF transmitters cannot help but move inside our bodies. In 2015, the wireless density factor will be at 10,000,000 transmitters / square kilometer or 10 transmitters per square meter. Given that the cross-sectional area of a human body is roughly .2 square meters, it becomes inevitable that some of these transmitters move from one side of the flesh to another. There will be issues with antennas from inside the body but with Phased Array technology, and the low levels of transmit power required to get from inside the body to outside, the issues will be overcome.
It's not clear at this time what would cause such a jump from outside a human to inside a human. One can only look at the chart and understand that the RF transmitters are there for humans and will tend to be closer and closer all the time. There will be body monitors; heart rate, glucose levels, blood pressure. There will be tags simply to track our position, either for family reasons or instrusive governmental reasons. There will be microphones and earphones that work incredibly well when attached to specific areas inside our bodies. There will be alert devices that we can feel in one way or another signaling events that we choose. Think of them as internal ringtones, either driven from our phone when it rings or from events entirely unrelated to mobile communication, such as calendar reminders or even hourly chimes, felt from inside instead of heard or seen from outside our bodies.
I welcome your thoughts on the "Wireless Density Factor" chart and the conjectures that chart imposes. Please send comments to me at michael.bengtson@gmail.com.