Search string in back ground search function

Hello All,

I'm stuck with a problem with cross catalog search in which i used function as background_search.

When i pass the searchstring parameter in the http request then it returns me certain number of products in HTML format.

But now, i want to get all the products from the catalog without passing the searchstring parameter in the http call then it lands on the home page of the shop instead of giving me the all products in HTML format.

Is there any way around to get the all products from back ground search function in OCI 5?

Thanks

Gurpreet