downloading in synaptic pkg mngr via mobile inernet too slow

may be this helps

disable ipv6
Please open a Terminal from the menu Applications->Accessories->Terminal and type:
(give your user password when requested, you don't see nothing when you type it, then press enter.)

sudo gedit /etc/modprobe.d/aliases
Modify the ipv6 row as below:
alias net-pf-10 off # ipv6
then add this row:
alias ipv6 off

to force kernel to not load ipv6 module
sudo gedit /etc/modprobe.d/blacklist
add a row as below:
blacklist ipv6

3) - you can also play with tcp/ip protocol kernel parameters
I use this parameters by adding them into /etc/sysctl.conf file (find yours)
sudo gedit /etc/sysctl.conf

net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_syncookies = 1
net.core.rmem_default = 16777216
net.core.rmem_max = 16777216
net.core.wmem_default = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
net.ipv4.tcp_rfc1337 = 1
net.ipv4.ip_no_pmtu_disc = 0
net.ipv4.tcp_sack = 1
net.ipv4.tcp_fack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_ecn = 0
net.ipv4.route.flush = 1

can u plse tell me what actually 'ipv6' is meant for? U also mentioned that
*"I use this parameters by adding them into /etc/sysctl.conf file (find
yours)". *How should i find mine???

google it u will get

actually there is no set methord to speed up the connection