More than 30 million CDMA 1X EV-DO and High Speed Packet Access (HSPA) users worldwide attest to the potential of mobile broadband service. It’s a service proposition that operators are increasingly likely to want to deliver to customers, almost regardless of their business models and of whether or not they currently hold a mobile operating license.

     The first generation of mobile broadband services is being provided over 3G networks. Expected upgrades to these networks will make broadband mobile services more attractive. Enhanced HSPA, expected in 2008, will provide up to 40 Mbit/s per cell in the downlink, and CDMA advocates claim 1X EV-DO Revision B will provide as much as 73.5 Mbit/s in around the same timeframe. But while it’s tempting to be impressed with these indicative roadmaps, both wireline and wireless technologies are maturing to a point where these approaches needn’t be the only platform for delivering broadband mobile services, nor even the primary ones.

     It’s been ten years since the first CDMA-based networks were launched using IS-95 CDMA with hierarchical network topologies consisting of base stations, base station controllers (BSCs), and mobile switching centers (MSCs). While throughput rates have since been improved with CDMA and Wideband CDMA, the network architectures have remained essentially the same. Indeed, extra nodes have been added in the form of the Serving GPRS Support Node (SGSN) and Gateway GPRS Support Node (GGSN) to support data services in GSM/W-CDMA as well as the equivalent Packet Data Serving Node (PDSN) in CDMA.

     Relative to the availability of new technology options, today’s 3G networks are sub-optimal for delivering mobile broadband services. The evolution of IP networking technology allows the potential for “flatter” architectures, promising a lower-cost, lower-latency network. Basic research into combining Orthogonal Frequency Division Multiplexing Access (OFDMA) has also steered the wireless operator and vendor community toward an emerging consensus that OFDMA is more robust, more spectrum-efficient, and more amenable to supporting multiple antenna systems (MAS) than CDMA. Combining these new technologies promises not just to extend throughput toward the 100 Mbit/s downlink mark and beyond, but also to do it at a significantly lower cost than legacy 3G architectures.