There are still unused numbers left out... For example in 93, 92 series of Reliance and Tata CDMA and they can be made use to their GSM cousins, say Docomo should be allotted in only 92xxxxx and not other 8xxxx or 90xxxxx and same for RGSM as 93xxxx.. For Airtel and Voda (GSM) the unused series in 94xxxxx can be shared with BSNL...
Further now in the current 10 digit number series, only around 10 to 13% of numbers are given to Mobiles and remaining >80% to LANDLINE numbers, which are very very low in volume... Like the 8xxx series, the unused STD codes in 7xxxx or 1xxxx can also be used... TRUE, then it will be very very difficult to distinguish between mobile and landline... But now the 801xxx series allotted to Karnataka IS nothing but SAME as what I said...
We need not go for the 11 digit mobile number.. For a 10 digit number, we can easily remember it in two equal parts and so remembering a 11 digit number will also be much more difficult...