AngularJS, Web API authentication

Problem Statement:

I am using AngularJS as my front end, I have a service layer to get/save data from/to database. Before doing this I want to authenticate the user and perform actions based on role of the user. I am using SQL Server as my database.

What I tried:

I tried having an endpoint expose and validate the user for every request. I tried having a session but unfortunately I somehow feel it is obsolete method and may be (because I have not tried on mobile) will not work fine with mobile.

What I am looking for

I am looking for token based authentication, to validate user against the SQL Server table and return a token and validate token for every request.

Can someone suggest me some links with custom database.

Note: If my request is not asking for too much, I would like to learn doing this using OWIN. If someone can suggest me OWIN method for my above request, I would be glad.