How can I use WCF Services without DataContract and DataMember?

I am working on a web application and serialize objects using JSON.Net

. Now I want to add some WCF services to this application that will be used on any platform like Android.

now when i send a simple ajax request to the web service it goes to endless loop and chrome loops logs net::ERR_CONNECTION_RESET

but when i add DataContract

to the model these problems are solved but in a different form throughout the application JSON.Net

does not serialize objects.

Here are my codes:

[ServiceContract]
public interface IProductService
{
    [OperationContract]
    [WebInvoke(
        Method = "GET",
        ResponseFormat = WebMessageFormat.Json,
        UriTemplate = "product/grid/special?start={start}&size={size}&orderBy={orderBy}&orderByType={orderByType}&productListId={productListId}")]
    PagedResult<Product> specialGrid(int start, int size, string orderBy, string orderByType, int productListId);
}

[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class ProductService : IProductService
{
    IProductRepository productRepository;

    public PagedResult<Product> specialGrid(int start, int size, string orderBy, string orderByType, int productListId)
    {
        //return start + " " + size + " " + orderBy + " " + orderByType + " " + productListId;
        productRepository = new ProductRepository();
        SearchOption s = new SearchOption(start, size, orderBy, orderByType);
        return productRepository.getSpecialSaleProducts(s, productListId);
    }
}

[Table("Product")]
[DataContract]
public class Product : BaseEntity
{
    public string title { get; set; }
}