Siemens Continues OFDM Push

Khoo writes "German telecommunications gear maker Siemens is backing a new kind of broadband wireless technology that will compete with Wi-Fi and 3G cellular services." As we covered recently, speed tests have been up to 360 Mbps and one of the latest rumours is that they will use it in conjunction with VoIP servers. That's unconfirmed, but particularly for new phone deployments, laying no wire would be nice. And Yes, Virginia - ITMJ is part of OSTG, like Slashdot.

Comments

To Clarify:

[Enigma_Man]

ITMJ, part of OSTG reports about OFDM to use VoIP?

Good...

-Jesse

Re:To Clarify:

[Anonymous Coward]

This article is an example that acronyms do not support understanding. OFDM is "orthogonal freqency division multiplexing". In other words, it's a kind of modulation. It does not compete with Wi-fi. 802.11g uses OFDM too.

Re:VoIP for Mobiles is overkill

[gl4ss]

that's exactly the point many people forget when they're hyping up voip for mobiles, that the for _mobile_ use networks already have been tuned for transferring voice as cheaply and well as possible.

(that is, if it really gets cheap enough to build wide coverage other networks they would still have the upper hand- now, they might change gradually into providing general data services rather than clearly seperated voice functionality, but that ain't gonna happen anytime soon totally)

so the ONLY reason to use VOIP over mobile networks would be artificially stupidly twisted pricing structure.

Why mark that as a troll?

[Andy Dodd]

I agree. OFDM isn't some sort of holy grail. It doesn't do anything that somehow invalidate's Shannon's Law for channel capacity, and it is quite possible to come within 0.5 dB of Shannon capacity with other modulation schemes. It's nothing special, just another method for modulation that happens to have certain benefits in some situations. (Examples include higher multipath immunity.) The European DVB-T (Terrestrial Digital Video Broadcast) standard uses OFDM and it's been around for a while (at least five years I think.) As the parent said, 802.11a and g use OFDM also.

OFDM is not a magic bullet. It's also not new.

Yes, Siemens' 360 Mbps number is impressive, but to achieve that performance, they either used some very interesting tricks (OFDM not being the key here, possibly a MIMO multiple-antenna system, a technology that is still under heavy research.), or made tradeoffs (high bandwidth or high SNR requirements) that will make the system useless for real-world deployment.