 Omaha was divided into ten sectors , codenamed ( from west to east ) : Charlie , Dog Green , Dog White , Dog Red , Easy Green , Easy White , Easy Red , Fox Green , Fox White , and Fox Red . The initial assault was to be made by two Regimental Combat Teams ( RCT ) , supported by two tank battalions , with two battalions of Rangers also attached . The infantry regiments were organized into three battalions each of around 1 @,@ 000 men . Each battalion was organized as three rifle companies each of up to 240 men , and a support company of up to 190 men . Infantry companies A through D belonged to the 1st battalion of a regiment , E through H to the 2nd , I through M to the 3rd ; the letter ‘ J ’ was not used . ( Individual companies will be referred to in this article by company and regiment , e.g. Company A of the 116th RCT will be ' A / 116 ' ) . In addition , each battalion had a headquarters company of up to 180 men . The tank battalions consisted of three companies , A through C , each of 16 tanks , while the Ranger battalions were organized into six companies , A through F , of around 65 men per company . V Corps ' 56th Signal Battalion was responsible for communications on Omaha Beach with the fleet offshore , especially routing requests for naval gunfire support to the destroyers and USS Arkansas . 
