The WiMax Forum wants operators to consider using Mobile WiMax – perhaps even using it instead of LTE, the mobile operators' officially anointed successor to 3G and HSPA networks. But can it really expect operators to change direction like that?

“LTE and WiMax are both overlays to cellular networks,” said Mo Shakouri, the WiMax Forum chairman “Operators need something for mobile data and LTE is a fork lift upgrade. If we can get enough deployments of Mobile WiMax. We have a shot at establishing ourselves.”

The point he is making is that operators need to add new capacity specifically for data, and their next steps for that are to use LTE or WiMax. Both of these use the same modulation technique (OFDM) as well as MIMO beam-forming. The addition has to be an overlay to the new network, and it has to be in new spectrum.

So operators can choose which to use. LTE has emerged from the 3GPP standards group, but is a data-oriented protocol, and interfaces to a new all-IP core network. WiMax also connects to that core. Both handle data, and operators are expected to move voice onto data.

“All roads lead to OFDM & MIMO,” is how a short white paper (PDF) from the WiMax Forum puts it. “Mobile WiMax (802;.16e) is already there.” WiMax has already used OFDM and MIMO for fixed networks, and wireless LAN is just adopting them for 802.11n.

Mobile WiMax could be preferable, the Forum says. It will have a vast array of devices, including dongles, smartphones and laptops, already on the market on Korea's WiBro. “A global industrial complex is in process of delivering the economies of scale of the PC industry to the mobile broadband area via WiMax,” says the white paper.

It's also going to be cheaper for operators, says the Forum, as they won't have to pay so much in licence fees for the IPR that is embodied in the radio equipment.

The message the Forum gives is that LTE doesn't have any inherently better upgrade path from today's 3G networks. It's simply come from the same people. The move to LTE doesn't have to be automatic.

So, I asked them, are you saying that LTE could be the Windows Vista of the 3GPP? The upgrade that's supposedly automatic, but which causes users to jib, and consider alternatives? The Forum doesn't tend to speak in quite such dramatic terms, but they liked the analogy.