[Samsung Epic 4G Touch] Beejis:
In order to make changes such as these (There may be more or better ones listed for the Epic 4g but these ones are for the EVO 4g) follow these guides:

http://xdaforums.com/showthread.php?t=733773

http://xdaforums.com/showthread.php?t=726877

First you will need your MSL. You can either go through the hassle of contacting Sprint and trying to get them to give it to you, or download a terminal emulator program from the market at follow these instructions:

Once in your preferred terminal program (connecbot, terminal emulator, etc.) type the following EXACTLY:

getprop ril.MSL

It should display your MSL.

From there you can do the 4G and 3G tweaks.

Turn 4g on, go to the dialer, enter ##3282# click view then click Wimax. Enter your MSL, scroll down and choose extensions from there. This is where you will change certain settings mentioned in the threads above. To change the following edits to suggestions below, just long press the option you want to edit and click write extension.

1. Scroll down the list and click on "WiMAX_Scan_Retry(s)"

2. Enter the number 15 and click "OK" (This equals 15 seconds instead of 120 seconds, stock is )

3. Scroll down the list and click on "WiMAX_Entry_Delay(s)"

4. Enter the number 0 and click "OK" (This equals 0 seconds instead of the stock of 300 seconds)

5. WiMAX_Entry_RX(RSSI)(dBm) - Default is -89. This is the minimum signal it has to be picking up to connect. I'm not sure what the best value here is, but the lower the number, the quicker the connect, since it will connect to a weaker signal. You'll have to experiment some with this, I recommend trying about -95 to -100 first. If it's unstable, raise the value closer to -89.

6. WiMAX_Exit_CINR(dB) - Default is 2. See the entry CINR value for an explanation of it. If the signal degrades to a CINR of 2, it will drop the connection. Change this to 1. This should let you stay connected longer. If you run into problems with staying connected but having an unreliable connection, change it back to 2.

7. WiMAX_Exit_Delay(s) - The default is 2. Since it's measured in seconds, that means if the CINR drops to 2 or below for 2 seconds, it will drop the connection. Raise it to 5. That should be enough to cover just a random drop in signal that will pick back up right away. That way you don't drop connection if you drive under a bridge or something (I'm rocking mine at 15s here, but it'll take any value up to 600 seconds, which is 10 minutes!)

8. EntryCINR, change from 0006 to 0004.

Thanks to Geniusdog254 and swatspyder for finding these tweaks!

3g streaming tweaks:

dial ##3282#

Enter MSL

Click on Others

Click on Multimedia

change the following settings to:

RTSP Proxy Address changed to 0.0.0.0

RTSP Proxy Port to 0

HTTPPD Proxy Address to 0.0.0.0

HTTPPD Proxy Port to 0

Stock is:

RTSP Proxy Address: rtsp.vog.sprintpcs.com

RTSP Proxy Port: 554

HTTPPD Proxy Address: pd.vog.sprintpcs.com

HTTPPD Proxy Port: 8085

AutoPrime was considerate enought to share a way to edit MAC addresses, if you are interested in how please go here, and don't forget to thank him/donate to him as well!

If you are on a AOSP/AOKP/MIUI rom, you can try this suggestion from Sahn-J