I live less than a mile from the UP triple track main (Kearney Sub) in central Nebraska, there are three MW/VHF towers within 20 miles of me. My question is do they use the MW system to assist with the VHF system? I hear several calls on a daily basis of the Kearney Sub dispatcher calling trains. I don't know where the dispatch center is located, my best guess is in Omaha. How does this system work?