After writing up a storm about the next-generation cellular Long-Term Evolution standard a few weeks ago, I noticed that several commenters were confused, critical or just plain wrong about LTE and WiMax, the other 4G network. So I called a few people and tried to figure out the salient differences between the two. First, both are 4G technologies designed to move data rather than voice. Both are IP networks based on OFDM technology — so rather than rivals such as GSM and CDMA, they’re more like siblings. But sibling rivalry does exist, so there’s still plenty of differences to hash out.

Let’s start with the genesis of the two technologies.WiMax is based on a IEEE standard (802.16), and like that other popular IEEE effort, Wi-Fi, it’s an open standard that was debated by a large community of engineers before getting ratified. In fact, we’re still waiting on the 802.16m standard for faster mobile WiMax to be ratified. The level of openness means WiMax equipment is standard and therefore cheaper to buy — sometimes half the cost and sometimes even less. Depending on the spectrum alloted for WiMax deployments and how the network is configured, this can mean a WiMax network is cheaper to build.

If WiMax is the hippie, grass-roots parents on “Family Ties,” LTE is closer to Alex P. Keaton. The players determining the LTE standard through the 3GPP are comprised of carriers and equipment vendors who have been buying and selling the same proprietary boxes for years. The open, standards-based way of doing business isn’t exactly their modus operandi.

Fred Wright, an SVP that handles 4G networks for Motorola, believes LTE will be the standard chosen by 80 percent of the carriers in the world — good news for vendors such as such as Alcatel-Lucent and Ericsson, who have opted to stick with LTE. Of course, as GSM is the dominant mobile standard today, such a prediction isn’t all that surprising.

However, LTE will take time to roll out, with deployments reaching mass adoption by 2012 . WiMax is out now, and more networks should be available later this year. As for speeds, LTE will be faster than the current generation of WiMax, but 802.16m that should be ratified in 2009 is fairly similar in speeds.

So despite their differences in origin and current availability, the two siblings may grow closer with time, especially as newer iterations on the standard emerge. Wright said 85 percent of the work and technology for WiMax equipment will be reused in Motorola’s LTE equipment designs. The true battle isn’t between the competing 4G networks, but between wireless and wired broadband.

“The performance and capabilities of WiMax and LTE will only get better over time, and will represent a direct competitive threat to the existing broadband services,” Wright says. “People will make a choice, just like today when people are disconnecting their wired lines for voice.”

It’s an ambitious goal, and aside from the networking technology, things such as backhaul capacity, and availability of network devices will determine how wireless our world will become.