webservice I am doing, want to check device type (phone, computer,.....) are connected to the webservice. to perform assigned access rights for each type of device,
please help me
You could try and do some browser sniffing -- they are http requests and they should have all the typical headers including user agents. Phones can also be sniffed based on IP address to some extent -- you can at least pick up on 3g users as they will be on the carrier's networks.
All that said, you are probably better off setting up some sort of authentication scheme that takes this angle into account as sniffing is far from perfect.