Minimum Signal Strength for tcp/ip(GPRS)

Please tell me what is the minimum signal strength required for working with GPRS tcp/ip socket data transfer.

There is no “magic number” above which it will “just work” and below which it won’t!

The Fastrack User Guide suggests that 0-10 is “insufficient”, and 11-31 is “sufficient” for calls; GPRS will tolerate somewhat lower levels, and SMS is the least demanding.

I would suggest that anything below about 7 should be regarded as pretty poor.

Does BER (bit error rate) also matters?