The WindoWSIL

I just heard that the mobile WiMAX standard (IEEE 802.16e) was approved as the sixth international standard for the IMT-2000 third-generation (3G) telecommunication platform, by the International Telecommunication Union (ITU) today. The decision may accelerate the transition from the 2.XG to the 3.XG, but it depends on the operators. Also, the competitor for the mobile WiMAX will be, in my point of view, the legacy WiFi or the IEEE 802.11n standard.

When I came to Austin permanently in July and took a metro bus, I was so surprised about the wireless internet accessibility in a moving bus. At first I thought it was the mobile WiMAX, but it was not. Still I am not sure it is the EDGE (2.5G) or the WiFi (APs along the path), but it is fast enough (for a grad-student) to check my email, and moreover, it is FREE. For me, there’s no demand to use the mobile WiMAX, especially if I pay for it. I can use free WiFi on the campus, in a bus and even in my home (thanks to my reckless neighbor).

I am curious how the operator (such as Sprint, who is implementing the Mobile WiMAX around DC area) take advantage of the official approval today. They may combine it with legacy system to reduce the deployment cost, but the money for the FCC to license the band (5 - 20MHz) will be huge. if they convince some potential users (including me) to pay some money for the service, the money doesn’t matter. But if they don’t, I think they may not win in the 3G game - a step stone to the promising 4G, regardless of the new technological features in itself.

What is your opinion?

I have been watching the developments in nanotechnology as a potential enabler for the new generation of wireless systems. I was initally captivated by the idea of creating a vaccum tube on a wafer using carbon nano tubes. While traditional vaccum tubes are inefficient, they have very high gains which are difficult to realize in solid state electronics. I think analog signal processing is bound to come back…

In any case, I think this paper is a significant stepping stone towards this direction. The paper is here. They even have a demo video (and a nice taste for Irish music).

I am glad to be writing the first post from a 3G device. Wireless is really great. It seems though that 3G is here maybe 7 years late. In any case I look forward to working with some MIMO enabled devices soon. Wsil let’s make this a reality!

Andy Reed, a pretty famous guy in the CS circuit (for fundamental contributions to the Intertubes), has said in an interview for popular media (I can’t find the article at the moment) that we’re missing something.  He says that interference should not exist.  Specifically, visible light (apparently) doesn’t interfere; hold up two same-colored LEDs and you could clearly detect information coming from either source (say, if they were pulsing).  So why should there be RF interference?

That was pretty much the entire article.   I wish I knew more about electromagnetics and quantum physics in order to refute it.  Of course the “only” difference between visible light and RF is the wavelength (or frequency) of propagation.  But quantum physics seems to tell us that particles (of any kind, including photons) are neither waves nor particles in the classical sense.  Some of their behavior is wave-like, some is particle-like.

At RF frequencies, photons are more wave-like.  At visible frequencies, they more particle-like.   I guess Reed seems to think (and may have some reason to that I’m unaware of) that we can exploit the photon’s more particle-like nature at RF.  Of course the article suggests no way of doing so, and Reed probably doesn’t as well.
Anyone know anything about this beyond my 2nd grade knowledge?

It’s hard to believe, but another semester is in the books. I’d just like to update the status of the WSIL.

• In February, Runhua Chen successfully defended his thesis titled “Multiuser MIMO Communication Systems with Cooperative Transmission”. A special congratulations is in order for Runhua and we wish him the best of luck as he transitions into the his new life in the real world.
• Postdoctoal scholar Dr. Seijoon Shim will be returning to Korea after spending over a year at UT. Dr. Shim will always be remembered fondly in Austin, TX for his killer vocals of ’80s era metal rock songs. Good luck to Dr. Shim in his new position…don’t forget to visit us at the WSIL from time to time, Dr. Shim.
• During this semester, 3 new members have joined the WSIL. In January 2007, Takao Inoue returned to UT from Japan to provide the WSIL with a jack-of-all-trades PhD student. Masters students Sanmi Koyejo and Steve Peters also joined the group to pursue their PhDs. Good luck to all of these students in their future at UT.

Today I came across an interesting feature in Adobe Acrobat. In the View menu, check out the Read Out Loud option. Try it with some Trans IT papers and see what happens…

Perhaps Robert could record the MIMO song for us!

Chan-Byoung made a good post on this topic a while back, and I think we should have some discussion of this based on this guide that I’ve started reading recently.

One of my initial observations is that each student should assume most of the responsibility of “being a good graduate student,” but that the advisor should help the student to some extent in this regard. If I had been proactive enough to look for these online guides two (or even four) years ago, hmmm…

Robert, do you have any thoughts on this?

As Lee Corso of College Gameday on ESPN would say “Not so fast, my friend!” I know I’ve heard that “MIMO is dead” many times since 2004 when I joined the WSIL at the University of Texas. This claim is usually a result of two opinions: (1) We know everything we need to know about MIMO (2) MIMO only works well in simulations, not the real world. In my opinion, to automatically dismiss wireless research because it focuses on MIMO techniques is a bit shallow. While it is true that the wireless community’s conceptual understanding of MIMO communication theory is very advanced, much of this theoretical understanding of MIMO is insufficient to make MIMO work in the real world. Recent research into practical feedback methods, mutli-user MIMO, and MAC-design in MIMO networks are just a few research topics that will likely, in part, enable future wireless implementations.

Not convinced? At the January IEEE meeting in London, a plan for 802.16m was formally announced. 802.16m, a sequel of WiMax will deliver a maximum of 1 Gbps. One of the proposed components of such a system is a large number of transmit and receive antennas. Many are skeptical that such deliverables are possible since this is more than ten times the throughput of current WiMax systems. If you look at technology throughout history, there’s always been this battle between the “visionaries” and the “realists”. Twenty years ago who would have believed you could make telephone calls, watch color television/on-demand videos, listen to any music you desire, and connect to a world-wide network of computing devices all on a electronics component smaller than your wallet?

We may never deliver 1 Gbps wireless traffic in mobile systems by using the current allocated bandwidth with MIMO techniques, but we’re not fully realizing MIMO’s potential either. To say that “MIMO is Dead” is just plain silly.

You might want to check this out to make sure. I think some of us may be suffering from this. A special thanks is in store for Eric Blossom of GNU radio fame for raising awareness.

For those of you who aren’t aware, there’s a technique called Bluesnarfing where security flaws in Bluetooth networks are exploited to take control of mobile phones. Hackers have been able to take advantage and make a decent buck as displayed in this YouTube video. Pretty scary stuff. Anybody know the particulars of this security flaw?