I keep getting e-mails saying that I am putting too much emphasis on the single claim that “xMax can use 1,000 to 100,000 times less power than comparable transmission technologies” and discussing it to the exclusion of other aspects of xMax, and in general making too big a deal of this, and what’s with this. Well, that may be so, but at least I am in good company. Looking at the xG Technology webpage I see the following statement:
“The key value proposition for xMax is that it lowers the cost of deploying broadband services. xMax accomplishes this by increasing the range of RF signals. By delivering broadband signals significantly farther than other technologies operating at the same frequency and power level, xMax reduces the amount of infrastructure required to cover a given area wirelessly by 25-50 fold depending on the terrain.”
Just so the reader understands, this is equivalent to saying that xMax can operate at 1000 – 100,000 times lower received power than “other technologies operating at the same frequency and power level”. To see this consider the following. A 25-50 fold increase in area coverage equals a 5 – 7 fold increase in range. Propagation loss in a typical urban area increases as the fourth power of distance, so 5 – 7 fold increase in range corresponds to an increase in pathloss which equals 5 to the fourth power to 7 to the fourth power. This in turn translates approximately to 1000 – 100,000 pathloss increase, or equivalently to a 1000 – 100,000 decrease in power (well a bit less, but I like nice round numbers). This is entirely consistent with statements attributed to xG Technology in many articles and documents one can find on-line.
In other words the xG Technology webpage clearly states that this claim is the key value proposition of xMax. What can I say? I happen to agree with them, and that is why I am discussing it. That it also why it should be very important to anyone interested in this technology to want to see clear unambiguous proof of the validity of this claim (such as the BER vs. Eb/N0 plot). Unfortunately, as I have explained in detail in earlier posts, this claim is in fact false. It is therefore not surprising that such proof is not available even at this late stage where the product is supposed to be ready for imminent rollout.