[Samsung Galaxy Nexus] thiagodark:
well, my logcat is pretty much like yours and i can't figure out what the hell is going on... my thread is this: http://xdaforums.com/showthread.php?t=1626593

the difference between my problem and your is that i can use my phone and avoid signal falling by using 2g network only. Have you tried to disable 3g network and see if signal still drops? because i can easily reproduce the problem actving 3g and trying to use the internet... and then, signal die!!

actually you can see the "airplane mode" going on and off (in the power menu) as the logcat pauses and starts again...

oh, and certainly is something wrong, whe my signal is okay, i got none of those outputs in logcat...

edit: i can even show what happens when i uncheck "2g only"

I/Use2GOnlyCheckBoxPreference( 386): get preferred network type=1
W/InputManagerService( 189): Starting input on non-focused client com.android.i
nternal.view.IInputMethodClient$Stub$Proxy@419aa028 (uid=1000 pid=1176)
I/ActivityManager( 189): Displayed com.android.phone/.Settings: +377ms
D/OpenGLRenderer( 1176): Flushing caches (mode 0)
I/Use2GOnlyCheckBoxPreference( 386): set preferred network type=0
W/BackupManagerService( 189): dataChanged but no participant pkg='com.android.p
roviders.settings' uid=1001
D/GsmUmtsOptions( 386): preferenceTreeClick: return true
D/ConnectivityService( 189): ConnectivityChange for mobile: DISCONNECTED/DISCON
NECTED
D/ConnectivityService( 189): Attempting to switch to wifi
D/ConnectivityService( 189): Attempting to switch to BLUETOOTH_TETHER
E/ConnectivityService( 189): Exception trying to remove a route: java.lang.Ille
galStateException: Unable to communicate with native dameon to add routes - com.
android.server.NativeDaemonConnectorException: Cmd {interface route remove rmnet
0 default 187.43.17.1 32 0.0.0.0} failed with code 400 : {Failed to remove route
from default table (No such process)}
E/ConnectivityService( 189): Exception trying to remove a route: java.lang.Ille
galStateException: Unable to communicate with native dameon to add routes - com.
android.server.NativeDaemonConnectorException: Cmd {interface route remove rmnet
0 default 0.0.0.0 0 187.43.17.1} failed with code 400 : {Failed to remove route
from default table (No such process)}
D/NetUtils( 189): android_net_utils_resetConnections in env=0xaac5f8 clazz=0x5d
800001 iface=rmnet0 mask=0x3
D/ConnectivityService( 189): resetConnections(rmnet0, 3)
W/Smack/Packet( 317): notify conn break (IOEx), close connection
I/qtaguid ( 317): Failed write_ctrl(u 76) res=-1 errno=22
I/qtaguid ( 317): Untagging socket 76 failed errno=-22
W/NetworkManagementSocketTagger( 317): untagSocket(76) failed with errno -22
D/ConnectivityService( 189): handleInetConditionChange: no active default netwo
rk - ignore
I/Use2GOnlyCheckBoxPreference( 386): set preferred network type done
D/Tethering( 189): MasterInitialState.processMessage what=3
D/dalvikvm( 189): GC_EXPLICIT freed 801K, 13% free 17125K/19591K, paused 4ms+4m
s
I/MediaUploader( 1133): No need to wake up
D/PicasaSyncManager( 1149): active network: null
D/PicasaSyncManager( 1149): background data: true
D/ConnectivityService( 189): ConnectivityChange for mobile: CONNECTED/CONNECTED

D/NetworkPolicy( 189): applying policy NetworkPolicy[NetworkTemplate: matchRule
=MOBILE_ALL, subscriberId=valid]: cycleDay=20, warningBytes=2147483648, limitByt
es=-1, lastSnooze=-1 to ifaces [rmnet0]
I/GTalkService/c( 317): [AndroidEndpoint@1098361552] connect: acct=1000000, sta
te=CONNECTING
I/GTalkService/c( 317): [GTalkConnection@1098676600] connect: acct=1, state=CON
NECTING
D/Tethering( 189): MasterInitialState.processMessage what=3
I/MediaUploader( 1133): No need to wake up
D/PicasaSyncManager( 1149): active network: NetworkInfo: type: mobile[EDGE], sta
te: CONNECTED/CONNECTED, reason: dataAttached, extra: gprs.oi.com.br, roaming: f
alse, failover: false, isAvailable: true
D/PicasaSyncManager( 1149): background data: true
D/dalvikvm( 386): GC_CONCURRENT freed 373K, 4% free 13425K/13895K, paused 5ms+5
ms
D/dalvikvm( 317): GC_CONCURRENT freed 416K, 4% free 13644K/14151K, paused 6ms+4
ms
D/ConnectivityService( 189): handleInetConditionHoldEnd: net=0, condition=100,
published condition=0
D/ConnectivityService( 189): ConnectivityChange for mobile: DISCONNECTED/DISCON
NECTED
D/ConnectivityService( 189): Attempting to switch to wifi
D/ConnectivityService( 189): Attempting to switch to BLUETOOTH_TETHER
D/NetUtils( 189): android_net_utils_resetConnections in env=0xaac5f8 clazz=0x78
f00001 iface=rmnet0 mask=0x3
D/ConnectivityService( 189): resetConnections(rmnet0, 3)
D/dalvikvm( 262): GC_CONCURRENT freed 502K, 5% free 14355K/14983K, paused 5ms+2
ms
D/NetworkLocator( 317): null cell state delivered
W/Smack/Packet( 317): notify conn break (IOEx), close connection
D/NetworkLocator( 317): null cell state delivered
D/NetworkLocator( 317): null cell state delivered
D/ ( 1273): [CP BOOT] __boot_6260: START CP BOOT
D/ ( 1273): [CP BOOT] __boot_6260: CP POWER ON DONE
D/ ( 1273): [CP BOOT] mipi_xmit_atat: SENT ATAT 0
I/qtaguid ( 317): Failed write_ctrl(u 76) res=-1 errno=22
I/qtaguid ( 317): Untagging socket 76 failed errno=-22
W/NetworkManagementSocketTagger( 317): untagSocket(76) failed with errno -22
D/ConnectivityService( 189): handleInetConditionChange: no active default netwo
rk - ignore
D/ ( 1273): [CP BOOT] mipi_xmit_atat: SENT ATAT 1
D/ ( 1273): [CP BOOT] __boot_6260: XIMT PSI DONE
D/ ( 1273): [CP BOOT] __boot_6260: XIMT EBL DONE
D/ ( 1273): [CP BOOT] __boot_6260: SET EBL DONE
D/ ( 1273): [CP BOOT] __boot_6260: REQSECSTART CMD DONE
D/Tethering( 189): MasterInitialState.processMessage what=3
I/MediaUploader( 1133): No need to wake up
D/PicasaSyncManager( 1149): active network: null
D/PicasaSyncManager( 1149): background data: true
D/dalvikvm( 340): GC_CONCURRENT freed 321K, 4% free 12872K/13319K, paused 9ms+3
ms
D/ ( 1273): [CP BOOT] __boot_6260: XMIT MODEM_MAIN DONE
D/ ( 1273): [CP BOOT] __boot_6260: XMIT MODEM_NV DONE
D/ ( 1273): [CP BOOT] __boot_6260: READ MPS DATA DONE : XEF
D/ ( 1273): [CP BOOT] __boot_6260: SEND MPS DONE : XEF(0x61080000)
D/ ( 1273): [CP BOOT] __boot_6260: REQSECEND CMD DONE
D/ ( 1273): [CP BOOT] __boot_6260: REQFORCEHWRESET CMD DONE
D/ ( 1273): [CP BOOT] boot_6260_mipi: CP FLASHLESS ALL DONE