Airvana, a wireless equipment vendor, has successfully completed a multi-carrier CDMA2000 1xEV-DO Revision B (Rev B) call in its lab, which a major step towards commercialization.Rev B is a multi-carrier system that combines multiple 1.25 MHz channels into one super channel, allowing users to share the compounded capacity of the combined spectrum. Several months ago, Qualcomm has shown a live demonstration of Rev. B that achieved a 9.3 Mbps downlink data rate in 5 MHz. Rev B can provide speeds of 5.4 Mbps on the reverse link (uplink) using three carriers (3x). The Rev B standard supports peak data rates of rates of 14.9 Mbps on the 3 carriers and 73.5 Mbps by aggregating 15 carriers within 20 MHz of bandwidth.
Rev B is a software upgrade to Rev A, so wireless providers can offer 4G-like services at a fraction of the capital investment required to build 4G networks. Rev B is fully backward compatible with Rev 0 and Rev A and provides seamless handoff between Rev. B and Rev. A/Rel. 0. Also, by upgrading to Rev B, operators will be able to boost data speeds for Rev A and Rev 0 users by reducing the overall load on the radio network.
Multi-carrier EV-DO is also expected to allow operators to increase the number of Rev A VoIP and push-to-talk users they could serve without affecting the experience of data users. In fact, in March Qualcomm demonstrated 114 simultaneous Voice over Internet protocol (VoIP) calls over a single 1.25 MHz channel in a single Rev. A Sector. In commercial deployment scenarios, EV-DO Rev. A’s capacity is expected to be up to 68 users in a 1.25 MHz single embedded sector, or about 475 simultaneous users in 10 MHz (a single embedded sector with seven 1.25 MHz carriers).
This VoIP field test employed a number of advanced Rev. A techniques including mobile receive diversity, equalization, interference cancellation, IP header reduction, End-to-end quality of service, and enhanced speech-processing algorithms to achieve voice quality and capacity comparable to traditional circuit-switched voice.
With WiMax on the horizon, it should be no surprise that wireless carriers who have no WiMax assets, will ramp up their efforts to increase the bandwidth offered to customers. Airvana expects to begin operator trials of Rev B multi-carrier EV-DO in Q3 2007.