Revenue from four licensees constituted approximately 56%, 10%, 10%  and 10% of the Company's revenue for the three months ended June 30, 2019 and revenue from four licensees constituted approximately 43%, 14%, 11% and 11% of the Company's revenue for the six months ended June 30, 2019. Revenue from three licensees constituted approximately 41%, 18% and 12% of the Company's revenue for the three months ended June 30, 2018 and revenue from one licensee constituted approximately 64% of the Company's revenue for the six months ended June 30, 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 June 30, 2018.  At June 30, 2019, royalty receivables from three licensees constituted in the aggregate approximately 82% 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.