Q: hey, i restored my iphone 3gs and activating problem occer

Where did you get the phone? That's typical of a device that was hacked or jailbroken to illegally unlock it.

There are actually many reasons a phone might show "no service," besides the phone being jailbroken. Here's a few things to try:

If you can't connect to a cellular network or cellular data - Apple Support

• Check your coverage area to make sure that you're in an area with cellular network coverage.
• Restart your iPhone or iPad.
• Check for a Carrier Settings Update.
• Take out the SIM card and put it back in. If the SIM card is damaged, or doesn't fit in the SIM tray, contact your carrier.
• Reset your Network Settings. Tap Settings > General > Reset > Reset Network Settings. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.
• Contact your carrier