Revenue from four licensees constituted approximately 80% of the Company's revenue for the three months ended March 31, 2019.  Revenue from one licensee constituted approximately 65% of the Company's revenue for the three months ended March 31, 2018.  Revenue from the sale of the Company's unsecured claim against Avaya, Inc. constituted approximately 32% of the Company's revenue for the three months ended March 31, 2018.  At March 31, 2019, royalty receivables from five licensees constituted in the aggregate approximately 93% of the Company's royalty receivables.  At December 31, 2018, royalty receivables from four licensees constituted in the aggregate approximately 80% of the Company's royalty receivables.