# [HOW TO] LOCK YOUR S4 IN 4G MODE



## LuckyDuck69 (Jun 24, 2011)

I take no credit for this. Original thread can be found here: http://forum.xda-developers.com/showthread.php?t=2309457

2100 Mhz speed test
I was able to gain access to the 2100 mhz spectrum here in the Portland area which is T-Mobiles LTE spectrum. unfortunately I was only able to gain access for about 5 min (we have some network issues in our area with the 2100 mhz spectrum it keeps going down probably network modifications for future LTE) and got speeds equivalent to the 1900 mhz spectrum since the 2100 Mhz spectrum here hasnt been converted for LTE use yet.

Here are the steps for the hack: 

Warning you will be locked into this spectrum only. So if you go out of a 4G area you will lose signal unless you revert it back.

1. Type this into the dialer *#27663368378#
2. Select "UMTS"
3. Select "debug screen"
4. Select "phone control"
5. Select "NAS control"
6. Select "RRC (HSPA) control
7. Select "change RRC revision
8. Select " Release 8 HSPA+

Then hit the menu key an select back (Warning if you hit the back soft key you will exit the settings an you will have to type the code in the dialer again an repeat steps 1-5) an repeat this till ur back to step 5 an select phone control again then.

1. Select "Dualmode network improvement" 
2. Select " Dualmode network on" 

Then hit the back soft key an exit then
1. Type this into the dialer *#27663368378#
2. Select "UMTS"
3. Select "debug screen"
4. Select "phone control"
5. Select "network control"
6. Select "band selection"
7. Select "prefered band selection"
Then select either bands WCDMA 1700, WCDMA 1900 mhz or WCDMA IMT2000 (2100 mhz is labeled as WCDMA IMT2000) (also WCDMA 850-900 will give you no data connection).

After selecting a band press the the back soft key to exit an run a speed test. Then repeat the steps 1-7 for the band selection process an find the fastest spectrum in your area. 

To revert back 
1. System settings
2. More options
3. Network modes
4. Select any of the network modes ie. LTE/GSM/WCDMA auto connect etc. Or whatever your rom has available for options.


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## anthony2558 (Aug 23, 2011)

Very cool. Thank you.

Sent from my SGH-M919 using Tapatalk 4 Beta


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