T-Mobile to refarm frequency spectrum, deploys HSPA to 1900MHz = iPhone compatibility
 

Hey folks,

I just read on engadget that T-Mobile is about to refarm its whole frequency spectrum:

http://www.tmonews.com/wp-content/up...1.52.17-PM.png

The current GSM spectrum in the 1900MHz will be largely rededicated to UMTS/HSPA, which will eliminate handset incompatibility for 3G for many devices including the iPhone, so you don't need an AWS-compatible handset for 3G access anymore. Instead any device supporting AT&T's 3G network will also work on T-Mobile's network.

Given this increase of capacity (or better: spectral efficiency) in the 1900MHz band T-Mobile will further rededicate some of the AWS spectrum to LTE.

T-Mobile will still have a very hard time to compete with the other US carriers who own a lot of spectrum on lower frequency bands, anyway this will be a significant improvement in my eyes.

more sources:
http://www.tmonews.com/2012/06/t-mob...san-francisco/
http://www.engadget.com/2012/07/11/t...-2g-discounts/

Cheers

I just realized that the first UMTS1900-capable cells have been popping up already since October 2011 but now it became official that the T-Mobile network will undergo a largescale refarming.

Also, lots of discussion here about it - T-Mobile is deploying 1900MHz HSPA/4G

Just be aware that in many markets T-Mobile has only 10 MHz of PCS-1900 spectrum, which is not enough to allow them to run both UMTS and GSM on that one block. AWS will continue to be T-Mobile's primary UMTS band for the foreseeable future.

A GSM network with a cluster size of 4 which is considered giving the best balance between capacity and interference would require 4.8 MHz of spectrum (see http://xa.yimg.com/kq/groups/2152165...4-phpapp01.doc). For UMTS you need a 5 MHz block.
If you add a guard band between the GSM and UMTS network of 0.2 MHz you end up with exactly 10 MHz.
So you definitley can operate a GSM and a UMTS network concurrently with 10 MHz of spectrum, however capacity would be modest. So they will need to shift as many users as possible to the AWS band in order to leave enough capacity on the 1900MHz band.

The problem is that US 10 MHz blocks are 10 MHz total (5 up & 5 down).

I see. Usually you don't add up uplink and downlink frequencies when talking about capacity of an FDD network. I assumed they had 10 MHz for the uplink and another 10 MHz for the downlink. Since UMTS requires a continous 5 MHz block, there's no compromise possible - T-Mobile has to make a choice between GSM and UMTS in these markets.