The other shoe has not yet formally dropped, but Clearwire now says it will conduct Long Term Evolution tests across its network, including both tests of frequency division and time division versions of LTE, plus the ability of LTE air interface technologies to coexist harmoniously with the existing WiMAX air interface already in use.
The tests do not definitively confirm a partial switch to LTE, but are a concrete bit of evidence that LTE will be part of Clearwire's future.
Clearwire intends to conduct FDD LTE (Frequency Division Duplex) tests using 40 MHz of spectrum, paired in 20 MHz contiguous channels, of its 2.5 GHz spectrum. Clearwire expects to confirm the capability to produce real-world download speeds that range from 20 Mbps to 70 Mbps. This is expected to be significantly faster than the 5 Mbps to 12 Mbps speeds currently envisioned by other LTE deployments in the U.S., which will rely on smaller pairs of 10 Mhz channels or less.
Clearwire will concurrently test TDD LTE (Time Division Duplex), in a 20 MHz configuration, which is twice the channel size currently used in its 4G WiMAX deployments.
Clearwire will also test WiMAX co-existence with both FDD LTE and TDD LTE to confirm the flexibility of its network and spectrum strength to simultaneously support a wide-range of devices across its all-IP network.
My own anecdotal experience with Clearwire's network is that, as you would expect, 4G is faster than 3G. But I have to say my experience also points out how much end user application latency is to be found elsewhere in the delivery ecosystem, such as the far-end servers. I also would observe that the 4G network signal seems more fragile than the 3G signal. Even in areas with both 4G and 3G available, the 4G often loses enough signal strength that my smartphone defaults back to 3G.
I'm not complaining, just noting that, as with many earlier increases in access bandwidth, faster is better, up to a point. If nothing else, having more access bandwidth simply points out latency elsewhere in the ecosystem.
