Here’s the licensing panel from eComm live and in color. Seeing yourself on TV is weird; my immediate reaction is to fast for about a month.
On a related note, see Saul Hansell’s musings on spectrum.
The issue I wanted to raise at eComm and couldn’t due to lack of time and the meandering speculations about collision-free networks is spectrum sharing. Two-way communications systems all need a shared pipe at some level, and the means by which access to the pipe are mediated distinguish one system from another. So far, the debate on white spaces in particular and open spectrum in general is about coding and power levels, the easy parts of the problem. The hard part is how the system decides which of a number of competing transmitters can access the pipe at any given time. The fact that speculative coding systems might permit multiple simultaneous connections on the same frequency in the same space/time moment doesn’t make this question go away, since they only help point-to-point communications. Internet access is inherently a point-to-multipoint problem as theses system all aggregate wireless systems in order to move them to the fiber backbone.
The advantage of licensing is that it provides the spectrum with an authorized bandwidth manager who can mediate among the desires of competing users and ensure fairness per dollar (or some similar policy.) The idea that we can simply dispense with a bandwidth manager in a wide-area network access system remains to be proved.
So I would submit that one of the principles that regulators need to consider when deciding between licensed and unlicensed uses is the efficiency of access. The notion that efficiency can be discarded in favor of ever-fatter pipes is obviously problematic in relation to wireless systems; they’re not making more spectrum.
Yoyo diets only make the problem worse. There’s no substitute for a lifestyle change that includes eating normal quantities but healthy foods and regular exercise.
Actually, coding systems such as CDMA are fine ways to allow spectrum sharing in point-to-multipoint systems. However, spectrum etiquettes such as 802.11y are even better, because they can in many cases eliminate the need for ongoing contention.
The use of CDMA in point-to-multipoint tends to be limited to resolving inter-access point contention rather than permitting multiple transmitters to a single access point. This is a fine thing to do, of course, but it doesn’t lead to the creation of unfettered spectrum.
When you say “tends to be limited” do you mean that it is not used for
multiple access to a base station or that it is ineffective as such?
In UWB, CDMA was limited to resolving interference between microcells. In the cell phone world, which I’m much less familiar with, this is probably not the case. In order to use CDMA in an aggregator, you obviously need to duplicate hardware per code channel. It would probably make a lot more sense to do this in a cell tower than in a microcell controller that supports direct link communication and has super-high bandwidth and limited power.