Steven J. Crowley, P.E.
Consulting Engineer
Archive for the ‘4G’ Category
ITU Loosens Hold on Term “4G” – Now Calls it “Undefined”
The debate won’t end but the volume is dropping on the what-is-4G controversy. Previously, I’ve written about the ITU’s characterization of 4G as only applying to the two radio technologies it has designated as IMT-Advanced: LTE-Advanced and WirelessMAN-Advanced (the latest version of WiMAX).
FCC Takes Further Steps toward Mobile Broadband in TV Spectrum
On November 30, the FCC adopted a Notice of Proposed Rulemaking (NPRM) as a preliminary step toward making the current TV broadcast spectrum available for use by fixed and mobile wireless broadband services. The proposed rules would do three things: 1) make fixed and mobile wireless services co-primary with broadcasting in the FCC’s Table of Frequency Allocations, 2) create a regulatory structure giving two or more TV stations the option to share one 6 MHz channel, and 3) improve VHF TV reception through power increases and adoption of receiver antenna standards. No service rules are being proposed; they’re to come later. Congress has yet to approve incentive auction authority.
ITU Gets “4G” Pushback from IEEE 802
The IEEE 802 Executive Committee today approved correspondence asking ITU for clarification on its use of the term “4G” in an October 21 press release on IMT-Advanced. The main concern is ITU’s characterization of IMT-Advanced as “true 4G.” IEEE 802 observes that some in industry and government use 4G to mean mobile broadband technologies other than IMT-Advanced. Consequently, IEEE 802 says, ITU’s announcement has caused such users to be on the receiving end of “public response” (i.e., negative publicity), and could cause “significant disruption” to existing technical activities and documentation. It also observes that such use of 4G seems inconsistent with ITU-R Working Party 5D’s prior consideration of the term.
The FCC’s Spectrum Deficit Estimate
The FCC’s National Broadband Plan (NBP) recommends that the Commission make available 500 MHz of new spectrum for wireless broadband, including 300 MHz for mobile use. In support of that recommendation, on October 21, the FCC released an FCC Omnibus Broadband Initiative technical paper: Mobile Broadband: The Benefits of Additional Spectrum. The paper concludes that mobile data demand is likely to exceed capacity in the near term and, in particular, that the spectrum deficit is likely to approach 300 MHz by 2014.
What’s 4G? Whatever you want.
On October 21 the ITU announced it had deemed two mobile broadband technologies as IMT-Advanced. They’re LTE-Advanced and WirelessMAN-Advanced (WiMAX Release 2 based on IEEE 802.16m). At the same time the ITU called these “true 4G technologies,” leading some in the trade press to say that marketing of some existing services as 4G is misleading.
No entity is the arbiter of the designations 2G, 3G, or 4G. Even the ITU generally uses these terms parenthetically. It recognizes the lack of consensus on their meaning, and does not say others are wrong. The ITU calls the IMT-Advanced technologies “true 4G,” and they are insofar as ITU has a view of 4G and the two technologies are truly consistent with that view.
In some of these articles, Sprint and Clearwire, to name two examples, catch flack for calling their current WiMAX offering 4G. I’d call it 3.5G, but I can’t say they’re wrong. An ABI Research analyst agrees with Sprint and Clearwire; his view is that everything TDMA is 2G, everything CDMA is 3G, and everything OFDMA is 4G, regardless of data rate. It’s a reasonable argument based on backward compatibility, but I’m not ready to agree. If that or something else ends up being the industry consensus, I won’t object.
Below is a comparison found on the ITU website. It’s generally consistent with my view.
Don’t like these classifications? Make your own. Within reason.
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UPDATED 11/04/2010
ABI analyst link updated with more current post.