These innovators – Qualcomm and Cerent – with their early success in markets that they established were not without major challenges from incumbent suppliers and standards-setting bodies. Strong opposition to Qualcomm’s CDMA innovation by the pro-TDMA forces, parading under the GSM banner in Europe, fought the introduction of this better technology solution, one that threatened the status quo. Similarly, opposition to Cerent’s MSPP innovation by the established SONET providers of decades old standards challenged a more streamlined implementation of optical transport that wrought many changes on the PSTN landscape.
Why not use feedback mechanisms to manage the power of a cell phone? Qualcomm’s engineers invoked a decades-old approach developed by Harold S. Black in the late 1920s – negative feedback.
Engineers understand that the gain of an amplifier is the ratio of the output voltage to the input voltage. In telephony, it is critical for clear calls to be set-up to design amplifiers with a nearly constant gain. However, transistors are imperfect components with varying specifications. Besides, a transistor’s gain varies with time, and the gain depends on the strength of the signal. The negative feedback amplifier reduces the effect of such changes on the gain of the transistors used. Qualcomm engineers used a series of Black’s feedback loops and other design innovations to process the digital signals and correct for errors. By providing for automatic gain control [1] in the handset and constant monitoring of both signal-to-noise and error rates, both voice bits and data traffic could be delivered more efficiently and cost-effectively than older TDMA-based cell phone networks.
Cerent’s approach embraced its own kind of simplification by posing a number of questions.
Why not include SONET’s popular optical bit rates into one network element instead of building four different boxes for each optical carrier (OC) bit rate?
Why not support an array of service interfaces to accommodate telephony, data, and video traffic types?
And, why not leverage the latest advances in technology to build a compact, low power-consumption network element at less than half the cost of existing systems?
Like Qualcomm in the wireless space, Cerent challenged the SONET oligopoly of Nortel, Lucent, Fujitsu, and Alcatel to introduce the world’s first Multi-Service Provisioning Platform (MSPP), one that embraced both voice and data simultaneously and became a force to support Internet carriage on top of existing voice traffic.
Phil Karn argued for wireless data, “. . . I’d been involved in the net at Bellcore since 1985 and I knew it was growing exponentially. Exponential growth has a way of mounting until even phone companies can notice it.” [2]
Wireless connectivity and data-friendly optical transport allowed for network operators, many who came and went during the past two decades, to meet the needs and demands of their customers.
[1] Qualcomm’s digital circuitry adjusted the power levels at a rate of more than eight hundred times per second.
[2] Karn’s quote comes from George Gilder’s book, Telecosm (2000).