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).