Adaptix says it has been issued Patent No. 7,164,669 five years after filing for it. The patent covers “methods for implementing multi-user Quality of Service (QoS)over OFDMA using information such as transmission rates, signal and noise conditions and traffic loading,” according to a statement released by the company. Orthogonal Frequency Division Multiple Access (OFDMA) is a multi-user version of OFDMdigital modulation. The full title of the patent is “Multi-carrier communication with time division multiplexing and carrier-selective loading.” Adaptix makes the the BX-3000 series of mobile base stations, which use a software-defined radio (SDR).
This could impact future voice on other systems as well, such as the Ultra Mobile Broadband technology the Third Generation Partnership Project is working on to improve the CDMA2000 mobile phone standard — UMB is essentially a WiMax competitor to come from Qualcomm, the company behind CDMA. Nortel just announced it has made the first live phone call over a UMB network, delivering both voice and video content in the demo. (Nortel claims it’s now made such calls on UMB, WiMax, and Long Term Evolution (LTE, for improving UMTS) connections). UMB, like others, has an OFDMA-based air interface. Nortel says it can maintain calls even as they roam between different connections, such as UMB to 2G, through use of its VoiceCall Continuity hand-over technology. Qualcomm UMB chips should start shipping in early 2008.