What is the difference between WiMAX and LTE ?
In order to answer this question better we are brining you an interview With Robert Syputa, senior analyst for Maravedis. He is an author of a report titled "WiMax, LTE and Broadband Wireless (Sub-11GHZ) Worldwide Market Trends 2008-2014 — 5th Edition."
Question: How have WiMax and LTE evolved?
Syputa: Of course, the basic technology is OFDM based. That goes back 40 some-odd years. It was developed for the military and aerospace. Outside of that, it was not commercially viable. Now it also is used in such areas as DSL and, more recently, in 802.11. So it pretty much waited for semi processor technology to catch up. That technology is coming along, and some of the other technologies like MIMO also are percolating up. So the traditional cellular wireless industry is not ignorant of this stuff.
Like everybody else, though, it was impractical until relatively recently. It was sitting on the back burner. Then the WiMax effort started up with some smaller companies, but also big ones including Nokia, Cisco and others. And the mobile version started getting developed with influence from Intel, Samsung, Motorola and others. So it started gaining momentum and woke up the cellular industry. They said that they can't let these gain a big share of the market. They saw it as a threat.
Question: So you suggest that the two segments — LTE and WiMax — are moving toward each other technically?
Syputa: All of these are moving toward ITU IMT, which provides a ubiquitous unified environment. They want to get 1.3 GHz of total spectrum across several different slots of spectrum. [In the end it will combine today's] cellular spectrum and new spectrum used under IMT-Advanced and create this unified communication system.
Question: Will the systems themselves evolve toward the same technology?
Syputa: Cellular and wireless companies came to the same conclusion, which is that it will be OFDM- and IP-based, rather than the CDMA that had come before it. Right now the main differences between LTE and WiMax are how the signals are modulated in the upstream and the downstream. Even those differences are diminishing because systems are much more adaptive, so they will use different modulations depending on the signal conditions or conditions from one point to the next. Also they are both using smart antenna technology to amplify the benefits of the core wireless. In that, they are very similar.
Question: So the technologies will be indistinguishable in the future?
Syputa: Yes, they will be. Now we are able to use multiple radio technologies on one piece of silicon. Just like in the cellular world today, we find different technologies in the same chip. In the future, the chips will be able to handle both WiMax and LTE. There will be some differences in IPR, and we will find multimode WiMax/LTE chips. If the user has an agreement to use both networks, he'll be able to use either WiMax or LTE.
Question: What about the WiMax model?
Syputa: The WiMax model is an open chaotic development environment. WiMax is wide open. The system is being proposed by companies that want to make it open. They want to have a piece, but want to do so by the virtue of having the best applications that run in that environment.
Question: So it seems that the real differences between WiMax and LTE are at this level, not at the technology levels?
Syputa: The real difference between WiMax and LTE is the business, how it's applied and the business model of operators. So a key question is how much user choice there is in determining the environment. The business models look to be different coming from different camps that have different motivations. The cellular industry wants to hold onto their revenue. The new participants — the Internet telephony companies and the entertainment participants such as gaming — want a seat at the table and don’t want terms dictated to them. Or at least they do not want to be bent over the barrel during negotiations. They want to see a much more open environment.
Very long term the business models of incumbents will change. But a huge ship doesn't turn around in a very short time span. I think the open environment of the WiMax model will win out to a large degree, but not entirely. LTE is trying to respond to the open model, and likely the industry will change over the course of time with the whole industry gravitating toward an open model.