avconv any video to 3gp format

In the following ,  the switch "-strict experimental"  is required only for aac decoding.
for rest of the formats it is not necessary.
bitrate notation in kbytes is compulsary or else mention in full number of  bytes.

avconv -i   inputfilenmae.mp4   -s   qcif   -vcodec h263   -r 10  -b 180k -ab 64k  -acodec   aac -strict experimental   -ac  1   -ar 22050     outputfilename.3gp