LTE Band Class Updates Tue, Nov 19, 2013

As I was completing my research for an upcoming blog on LTE Carrier Aggregation, I found that my previous LTE Band Class reference sheet was missing some of the more recent Band Class updates, so I decided to share my new reference document with a few comments.

FDD Band Classes:

The first notable band class addition in Band 30. This band class creates a definition for FDD operation in the WCS (2.3GHz) band which was previously defined only for TDD operation.

From the Spectrum Grid view of the Spectrum Ownership and Analysis Tool, you can see that Band 30 does not include the 5MHz channels that AT&T purchased to essentially become guard bands for the Satellite Audio guys. This will provide AT&T with a 10x10 LTE channel on a market by market basis, as they resolve the remaining ownership issues in the WCS band.

The next two band classes are not new, but I previously skipped over these band classes because I didn't fully understand their frequency breaks.

Band 26
Previously I thought this was a specific band for Sprint IDEN operation that is adjacent to the cellular band. This is the band where Sprint is placing their 2nd LTE channel (5 MHz) and a CDMA channel (1.23 MHz). Looking at the frequencies in detail, the band class covers the IDEN spectrum and the adjacent cellular spectrum.

This is similar to Sprint's Band 25 which includes all of the PCS band plus their G block spectrum (but not the H block).

So you would think that all of the North American carriers could standardize to Band 25 for PCS operation and Band 26 for Cellular. Using the latest iPhone 5s LTE band support,

you can see the Verizon, T-Mobile, and AT&T iPhone's support Band 2 and 25 for PCS, but only the cellular band (Band 5). Sprint iPhone 5s includes,

both Band 2 and 25 for PCS and Band 5 and 26 for cellular.

Band 10:

This is referenced as the AWS extended band and you can note from above that it is not currently applied to smartphones like the iPhone 5s. This band class seems to be a preparation for the future use of the AWS-2 and AWS-3 spectrum and the government shared use band that are both adjacent to the existing AWS spectrum band. Here is how the downlink looks in the Spectrum Ownership Analysis Tool:

Note that Band 10 does not cover the entire band contemplated for AWS-3, nor does it include Dish's Band 23. For the uplink:

This again depicts that Band 10 is not currently set to include the entire shared government opportunity.

TDD Band Classes:

Here is the reference sheet the TDD band classes.

On this reference sheet I hadn't looked closely at band classes 35, 36, and 37. I had always focused on the 2.3GHz and 2.5GHz as the only bands that were designated for TDD support in North America. These three band classes create 140MHz block of spectrum that could be for TDD deployment. Here is how these bands appear in the Spectrum Ownership Analysis Tool:

I'm not sure what the history is on these band classes, but they would support TDD operation in both the PCS uplink and downlink bands as well as in the 20 MHz between the bands. Since the PCS frequencies are highly deployed, I would consider it very unlikely to see TDD systems in this band in the near future, and I doubt that the PCS band is authorized for TDD operation. It will be interesting to see whether any of the wireless carriers begin to look this direction. With Sprint stepping out of the H block auction, they seem to be signalling that TDD operation is more important to them and the Band 37 block (including Sprint's G block) could be the reason why Dish is pushing forward in the H block auction. Please comment if you are aware why the 3GPP has included these 3 TDD band classes.

LTE Carrier Aggregation - What's Going On... Wed, Feb 13, 2013

Recently I reviewed the 3GPP Standards site to check in on the status of LTE Carrier Aggregation. I found a gold mine of information.

First a few definitions: Carrier Aggregation allows a wireless carrier to band together different blocks of their spectrum to form a larger pipe for LTE. This can be accomplished in two ways: Inter-band and Intra-band.

Inter-band combines spectrum from two different bands. The spectrum in each band to be combined must be contiguous within that band. Intra-band combines spectrum from two non-contiguous areas of the same band.

Here is a link to an article from 3GPP that explains Carrier Aggregation.

Below is a table summarizing the relevant 3GPP working group descriptions for Carrier Aggregation.

First of all, the current network release for all carriers is Release 9. T-Mobile, Sprint, and Clearwire have announced that they are deploying Release 9 equipment that is software up-gradable to Release 10 (LTE Advance). From the chart, it does not appear that there are any carrier configurations planned until Release 11. Release 10 appears to be a late 2013 commercial appearance and Release 11 will likely be very late 2014 or mid-2015. For Carrier Aggregation to work it must be enabled and configured at the cell site base station and a compatible handset must be available. The handsets will transmit and receive their LTE data on two different spectrum bands for the Inter-band solution. All handsets currently only operate in one mode, 700MHz, Cellular, PCS, AWS, or 2.5GHz.

Highlights by Carrier:
Canada: Rogers Wireless will have support for inter-band aggregation between their AWS spectrum and the paired blocks of 2.5GHz spectrum.

AT&T: Inter-band support in Release 11 for their Cellular and 700MHz spectrum, inter-band support to combine their AWS and Cellular spectrum, as well as configuration to support combining their PCS and 700MHz spectrum. All of the 700MHz band plans only include their 700B/C holdings. No 700MHz inter-operability.

USCellular: Inter-band support in Release 11 for Cellular and 700MHz (A/B/C). No support for PCS or AWS spectrum combinations

Clearwire: Intra-band support for the entire 2.5GHz band. China Mobile is also supporting this with an inter-band aggregation between 2.5GHz and their TDD 1.9GHz spectrum.

Sprint: Support in Release 12 for combining (intra-band)their holding across the PCS spectrum, including their G spectrum but not the un-auctioned H spectrum. No band support for their iDEN band or the 2.5GHz band.

T-Mobile: Support in Release 12 for intra-band in the AWS band and inter-band between AWS and PCS.

Verizon: Ericsson appears to be supporting Verizon's need to combine (inter-band) between AWS and 700MHz C. Not support for Verizon's Cellular or PCS holdings.

Dish: Release 12 support to combine their S band (AWS4) spectrum (inter-band) with the 700 MHz E holdings. This is the only aggregation scenerio for the US that combines FDD operation (AWS4) with TDD operation (700MHz E).

AT&T Carrier Aggregation - Band 5 and Band 17 Fri, Dec 14, 2012

Posted during the 3GPP RAN Meeting on Dec 4-7, 2012 in Barcelona, Spain.

Customer Requirements for LTE Advanced Carrier Aggregation for Band 5 and Band 17. This appears to be supporting AT&T's need to aggregate carriers between their 700MHz (Band 17) and the Cellular band (Band 5). No mention of including the redefined WCS band. Could this be a sign that AT&T's growth plan for LTE will be to grow into the cellular spectrum first, and then to the WCS spectrum?

T-Mobile (Deutsche Telekom Capital Markets Day 2012) Fri, Dec 07, 2012

There were several interesting details that came out of the Deutsche Telekom Capital Markets Day 2012. The primary announcement concerned T-Mobile USA being blessed with the ability to sell the iPhone. T-Mobile's new CEO, John Legere indicated that it will have a dramatically different experience than the other iPhone on the market. In addition T-Mobile will sell it unsubsidized, although they will offer financing plans. This should continue to drive T-Mobile's Cost Per Gross Add (CPGA) down, although they didn't disclose if this only affects their iPhone retail business or potentially all of their retail. This is a dramatic step which eliminate the primary issue that I have had with the subsidy pricing model. I have a problem with paying the same monthly rate for my smartphone if I am out of contract as the guy that who just got a new device. With T-Mobile's plan the true cost of upgrading will be carried by the customer, with the expectation of lower monthly rates.

Above is a restatement of the testing data from PC Magazine which T-Mobile released. It is interesting to note how far their speeds have fallen from their early announcements in late 2010 concerning the HSPA+ network. It is also worth noting that they compared AT&T's LTE network. You can again see the loading effect on the network. AT&T's Chicago network was launched September 2011 so it has been loading for over a year reflecting the slower speeds. AT&T's complete New York and San Francisco networks are much newer, launching September 2012, thus carrying less traffic. I am curious why T-Mobile did not chose to compare themselves to AT&T's 4G (HSPA+) network.

From a LTE network build perspective, this was the first time I have heard clearly that T-Mobile is deploying tower top electronics. It is interesting that they state that they are the first carrier in North America to broadly deploy radio-integrated antennas. Clearwire was the first carrier to deploy tower top base stations, followed by Sprint with their Network Vision project. T-Mobile is playing up the fact that their radios are some how integrated into the antenna. Not really an earth shattering announcement. From a technology perspective, deploying the tower top base stations will fill in coverage holes and improve data speeds so it is a good move. In addition, these base stations will be Release 10 capable, meaning a software update will move these radio from the LTE features to the LTE Advance features.

The Numbers: