Showing posts with label mobile. Show all posts
Showing posts with label mobile. Show all posts

Monday, December 28, 2009

Spectrum inventory and reallocation snowball keeps growing...


Recently on the 9AM Talk Net mailing list Kristen K6WX noted an AP article "Cell phone mania forces scramble for more airwaves". This article came out on the same day Mashable reported that AT&T has stopped selling the iPhone in New York City; presumably because AT&T is finding that their network can't handle the data traffic. The AP article reports that the CTIA is asking the FCC for an additional 500 MHz of spectrum to handle current and anticipated capacity needs.

FCC chairman Genachowsky began talking about a looming spectrum crisis back in November, so it's not a surprise to me that a month later AT&T is shutting off iPhone sales in one of the most densely populated and highly-mobile cities in the USA; what better way to build populist outrage which will encourage Congress to support bills such as John Kerry's SB 649 "Radio Spectrum Inventory Act" and Henry Waxman's companion HR 3125? I wrote about SB 649, and how it potentially threatens amateur radio, back in March 2009.

Another recent development from the FCC is an effort which would terminate most or all over-the-air (OTA) broadcast television. Theoretically; if the FCC could migrate all OTA TV to cable, wired broadband, or some sort of multiplexed digital wireless system this would free up 300 MHz of spectrum. CTIA is asking the FCC for 500 MHz of spectrum, so the FCC would still need to locate 200 MHz of additional spectrum. It's unlikely that any amateur bands below 1 GHz would serve the cellular industry's needs, but consider our allocations above 1 GHz:
  • 1240 - 1300 MHz = 60 MHz
  • 2300 - 2310 MHz = 10 MHz
  • 2390 - 2450 MHz = 60 MHz (In reality; 10 MHz see [a])
  • 3300 - 3500 MHz = 200 MHz
  • 5650 - 5925 MHz = 275 MHz (In reality; 0 MHz see [b])
[a] It's unlikely that the FCC would disturb the lucrative Wi-Fi business, so I presume that 2400 - 2483.5 MHz will be off-limits i.e. this leaves 10 MHz available for reallocation.

[b] This band overlaps with the UNII 5.7 GHz band's channels 128 - 165; so again the Wi-Fi (802.11a) industry will likely trump any CTIA interests.

Thus I'm going on record today with my prediction that 3300 - 3500 MHz is the band likely threatened by SB649/HR3125 or future variants. Of course it could be argued "So what?" and you'd be right; in all honesty how many hams are active in the 3300 - 3500 MHz band? A few guys in the 50 MHz And Up Club? 200 MHz of spectrum will bring in a LOT of money in a spectrum auction.

And the FCC will need that money, because apparently the FCC is planning to pay the NAB and TV broadcasters (who never paid for, and thus don't actually own, their spectrum) about $12 billion to shut down OTA television and migrate to the aforementioned cable, wired broadband, or multiplexed digital wireless system.

An additional $9 billion would be spent (think "DTV Converter Box Coupon" program -- on steroids) to migrate households to the new system. So in the end; the FCC wants to spend $21 billion dollars to ensure that the cellular industry has room to grow. Good thing Congress recently raised the debt ceiling to $12.4 trillion, eh?

I suppose that in the long run this makes sense; the tax revenues from adding more mobile phone subscribers is potentially huge; especially if the IRS succeeds in making it harder for taxpayers to count mobile phone expenses as a deduction. What frosts me is the idea that the NAB, who didn't pay for their spectrum to begin with, stands to reap a $12B windfall. Good work if you can get it.

Thursday, April 5, 2007

Public speaking: IITBHF -- The Future of Mobile Computing


I've been invited to be the moderator of a panel at the IIT Bombay Heritage Fund event "The Future of Mobile Computing". Panelists will be from Greylock, Beceem, Mobio, and Norwest Venture.

Saturday, March 17, 2007

Public speaking: MIT CNC -- The Future of Portable Communication

I was invited to be a panelist at the MIT Club of Northern California's Entrepreneurship series "What’s In Your Pocket? The Future of Portable Communication" event. Other panelists were from OQO, Digital Chocolate, NVIDIA, and HP Labs. Julie Ask from JupiterKagen moderated.

My fellow panelist Susie Wee from HP Labs wrote about the event in her blog. She quoted me as expressing some reservations about the viability of WiMAX in the face of a nearly ubiquitous Wi-Fi install base. This is essentially correct, however WiMAX being a somewhat diaphonous term it's important to make distinctions on what use-model I was referring to.

I personally believe that Mobile WiMAX (IEEE 802.16e) will never happen due primarily to the nearly universal attach rate of Wi-Fi to mobile consumer devices, which severely drives down the potential for widespread adoption of Mobile WiMAX. It's estimated that by late 2009 it will be essentially impossible to purchase a laptop without 802.11, and that most will be 802.11n. This trend likely holds true for handheld devices (PDAs, SmartPhones, etc) if for no other reason than chip manufacturers will simply stop building non-11n parts at some point.

The essential question is; If the installed base technology is viable, and a network exists, then why change? Novarum has done extensive real-world use model system testing, and subsequent analyses in their "Wireless Broadband Rankings" and "Metro Wi-Fi Rankings" show that actual throughput of many municipal Wi-Fi deployments is approximately the promised performance of as-yet-undeployed WiMAX systems. 3G & LTE deployments from cellular carriers are increasing footprints daily and coming up the throughput curve. So why change, and why will anyone invest capital in spectrum, equipment, siting, and deployment of a Mobile WiMAX system that in the end will only be as good as what's already available?

The logistical and financial challenges of deploying wide-area wireless networks are rather severe and (most fortunately for those people trying to get investors to drink the WiMAX Kool-Aid) not well understood by more than the relative handful of people who've actually done such work. Those who don't understand history (anyone remember Metricom's Ricochet network?) are doomed to repeat it.

I believe that Mobile WiMAX might find a niche in non-stationary backhaul i.e. broadband on commuter trains, etc but I don't believe it will ever be the "last yard" connection for mobile devices. Fixed WiMAX has a better chance, especially in rural areas of the US which aren't served easily by broadband. Fixed WiMAX also stands a strong chance of succeeding in developing regions outside the United States.