sharepoint - Could not find assembly System.ServiceModel -

I am deploying a webpoint on SharePoint and receiving some errors, the data from the WebPart Web Service uses and Displays a chart using Microsoft Chart (Framework 3.5). When I try to get it, I get a failing error:

The file or the assembly could not be loaded 'System.ServiceModel, Version = 3.0.0.0, Culture = Neutral , PublicKeyToken = b77a5c561934e089 'or one can not specify the system file for its dependency.

StackTrace: On the system. Web. Service. Protocol. SAPHTP Client Protocol. ReidSpain (Soap Client Messaging Messaging, WebRespace Response, Stream Revive, Boolean Asyncroll)
Systems. on the web. Services.Protocols.SoapHttpClientProtocol.Invoke (string filename, object [] parameters)

I system. Tried to copy Saricemodel.dll to bin folder and registered it on GAC, but there was no change in error. Any ideas?

Thanks

To expand on the answers given above:

This is running on your site like asp net 2.x Being that of the system. Service model is a 3.x component, the assembly will not load.