Upgrading D-Link DIR-456U Firmware

Hoping to find 3G only instead of Auto in the 3G Internet access option, upgraded the firmware from 1.01 to 1.02.. NO SUCH option is available.
Firmware Version: dir456u_fw102b06.rar
unrar the file will fetch a .bin file which needs to be uploaded

BSNL 3G update (SMS)
Dear Customer,
From 01-Mar-2015, your bundled free data will be credited on monthly basis instead of the earlier 12-month consolidated basis. Every month free usage will be credited and the previous month's balance will be cleared. Additional data can be availed using any data STVs.
If Data-plan Voucher is again used before the plan expiry, the benefits will be given freshly. Data-Plan 3299- 2.5GB/month,DP2299- 1.5GB/month,DP1251- 0.75GB/month. Validity-12 months."Monthly credit" will start after expiry of validity or on recharge.