Alright, just tested and it works on Fido.
Currently tested on:
Rogers from Toronto
Fido from Vancouver
Instructions to enable Stable LTE on C6603 (havent tested on C6602)
1) Download
ZL FTF C6506
2) Set C6603 to USB debugging mode
3) Open flash tool and flash
Baseband ONLY, Exclude everything else, and Do not wipe data, cache, applog.
4) After flashing and rebooting, go and set the correct LTE APN settings for your carrier.
5) Set network mode to LTE(preferred)/WCDMA/GSM
6) Thank
athris
To set your APN settings
Settings > More > Mobile Networks > Access Point Names > New
Fido LTE APN settings:
APN: LTEMOBILE.APN
Add the following if you want mms too
MMSC:
http://mms.fido.ca
MMS Proxy: 205.151.11.13
MMS Port: 80
Rogers LTE APN settings:
APN: LTEMOBILE.APN
Add the following if you want mms too
MMSC:
http://mms.gprs.rogers.com
MMS Proxy: 10.128.1.69
MMS Port: 80