no service error after upgrade to ios5.0.1

sir
i got no service error message after upgrade my iphone 3gs ios5.0.1 from 4.1 my base band 06.15.00 shsh:4.0.1, 4.1,4.2 ,i did the following steps for upgrade from google search
downloaded : sn0wbreeze v2.8b11 , iPhone2,1_5.0.1_9A405_Restore

Step 1. Opened Sn0wbreeze and browse for the 5.0.1 firmware
Step 2. Select new boot rom
Step 3. Choose expert mode.
Step 4. Click on general then next. with in the general option click check the box “activate the iPhone”.
Step 5. Click next then choosed build ipsw then click next again.
Step 6. ipsw is done, sn0wbreze guided in putting device into a pwnd DFU mode.
Step 7. Opened Itunes and shift click or option click on restore. Browse for the sn0wbreeze ipsw that was created on desktop.
Step 8. After it is done restoring my device stuck on the apple logo screen. Open up iBooty
Step 9. In iBooty just selected device and put my device into DFU mode device then boot up.
then i configured and opened cydia installed ultrasnow after that reboot my device

but my device shown now no service. please help me for solve this.

 

sir please what can i do get back mobile service, can u tell me how to unlock my 06.15.00 bb mobile

 

anybody help me my iphone have no service error

 

i tried restore ios5.0.1 again but i got error 1694 ,1600 please help