[Q] Galaxy S2 looses network topic

hi. I have a samsung galaxy s2 i9100 (for now 3 and half years)

i am in the uk with 3 network



for some time i have been experiencing loss of network all of a sudden thoughout the day
specially if i tether my phone via wireless

i have changed its software (rom and modem) and I am still experiencing this loss of network

in order to get network again I must reboot the phone, it is the only way of getting it back working




I travel a lot to Portugal and take the phone but I do not seem to have experienced this there
tough i dont tether there nor i use the connection for data



currently i am using a slim rom 4.2.2 build 8 official

the baseband is i9100xxLs9


any toughts about what is happening? do you think the phone is to blame? software? hardware? sim card?