The present invention relates to a data unit sending means and a method for controlling a data unit sending means, where data units of a first protocol (L2_ARQ) embed data units of a second protocol (L3) belonging to a higher layer, and said data units of said first protocol (L2_ARQ) are held in a send...http://www.google.com/patents/US6816471?utm_source=gb-gplus-sharePatent US6816471 - Data unit sending means and control method
