Several people have asked me “Won’t 4G mobile broadband services solve the broadband problem?” Hardly!
Despite President Obama’s support for widespread 4G mobile broadband coverage, there is no way 4G mobile technologies (like LTE and WiMAX) will provide the kinds of capacity we need to keep the US competitive with the rest of the world. For that we need fiber augmented with short range high capacity fixed wireless links. The problem is mobile broadband capacity lags that of fixed links and its available capacity is spread too thin.
For a real-world measurement of sustained data rates on Clearwire’s 4G network, look at this data from NetFlix. Average sustained throughput of Clearwire’s 4G network is less than that of DSL services! NetFlix would like to stream 2-4 Mbps, but for Clearwire customers they have to cut back to less than 1.6 Mbps on average.
Verizon is likely to do a bit better than Clearwire, not because their LTE technology is inherently better than Clearwire’s WiMAX (they are very similar), but because Verizon is deploying the latest LTE gear while Clearwire’s technology is from a year or two earlier.
netBlazr, on the other hand, uses multiple short-range 100 Mbps point-to-point links, working outward from buildings where Gigabit fiber connections are available. One of our headends can source 10x more data than most 4G cell sites. As a practical matter, this means we can provide burst rates of 80 Mbps or more and we can offer committed data rate services (something no mobile broadband provider will attempt).
Verizon’s LTE network
Here’s an analysis I did two months ago for another purpose.
Verizon is deploying LTE on their 700 MHz spectrum. The spectrum they own is referred to as the C block in the 700 Mhz band. This block is actually 22 MHz of spectrum in two separate ranges, 746-757 MHz and 776-787 MHz, i.e. “2×11” in LTE terms.
To the best of my knowledge Verizon is deploying gear from Alcatel-Lucent and Ericsson. It’s LTE based on 3GPP Release 8 with 2×2 MIMO using FDD with 10 MHz down and 10 MHz up. There is a plausible summary of such technology in a Motorola white paper here: http://business.motorola.com/experiencelte/lte-depth.html
While in theory, the absolute peak downlink speed for a single user in a single sector can approach 59 Mbps, the average sector throughput for multiple users is a fairly modest 15.7 Mbps down and 6.35 Mbps up (that’s the sustained sum of multiple users). Any real system is likely to have multiple users (except perhaps at 2am), so Verizon’s claim that users will see 5-12 Mbps download speeds (and 2-5 Mbps up) is probably safe, as long as they keep their network build out ahead of their users, i.e. ahead of congestion.
PC magazine reports that Verizon engineers claim to have seen download speeds of 40-45 Mbps. That’s probably a single user measurement. PC magazine’s Sacha Segan reports (12.03.2010) a peak measurement with Ookla speedtest of 21.2 Mbps download and 5.8 Mbps up, but that was several days ahead of the service launch, i.e. on an unloaded network. In the same measurements, Sacha reports average measurements of 14.9 down and 5.4 up. In another set of measurements (12.01.2010) Sacha reports 10 Mbps down and 5.5 Mbps up.
The main issue is Verizon cannot offer the committed data rate services that netBlazr (or any coax or fiber fixed-line service) can offer as Verizon can only count on having 15.7 Mbps total available capacity (per sector) under a multi-user load (47.1 Mbps per cell site for 3-sector sites).
netBlazr has 400-800 Mbps of real committable, salable capacity available at each head end, today.
Clearwire has more spectrum than Verizon
Clearwire’s service (Clear, which is also sold as Sprint 4G) uses WiMAX technology which is technically very similar to LTE but started a few years ahead. Unfortunately that means the technology that Clearwire/Sprint is deploying is not quite as advanced as the latest LTE technology, so the current Clearwire network is slightly behind what Verizon is starting to deploy. On the other hand, Clearwire owns much more spectrum. They recently tested LTE on their spectrum using 2×20 MHz channels. That’s twice the spectrum that Verizon owns and, not surprisingly, Clearwire got 90 Mbps peak downloads (versus 40-45 Mbps peak that Verizon engineers measured). In the future, Clearwire/Sprint is likely to do better than Verizon just because they own more spectrum.
But netBlazr has the most!
However, in the future, netBlazr will also have faster technology! Also, while our spectrum is license-exempt, we have vastly more spectrum available – a minimum of ten 40 MHz channels versus two 20 MHz channels for Clearwire/Sprint and two 10 MHz channels for Verizon. Also, while we are not using Wi-Fi in it’s conventional sense (hot-spots) we are leveraging Wi-Fi technology. This is important as the Wi-Fi market tends to deploy new wireless technology several years in advance of the cellular industry.