What are two reasons that video conferencing solutions developed before the 1990s were impractical? (Choose two)

Video conferencing solutions developed before the 1990s were largely impractical for widespread use due to two primary factors: exorbitant cost and poor technical performance. The systems required specialized, bulky hardware and dedicated, high-capacity transmission lines (e.g., T1 or multiple ISDN lines), which were extremely expensive to lease and operate. Concurrently, the compression and transmission technology of the era was limited, resulting in low-resolution, low-frame-rate video. This produced a jerky, unclear, and often unreliable image, which significantly undermined the user experience and the effectiveness of the communication, making it an unviable solution for most organizations.

C. They produced high-resolution image quality. Early systems were severely limited by bandwidth and processing power, resulting in very low-resolution, not high-resolution, images.
D. They had not been invented yet. The concept and working prototypes, such as AT&T's Picturephone, existed as early as the 1960s, well before the 1990s.
E. They operated at a high frame rate. These systems operated at very low frame rates (often below 15 fps), which caused unnatural, jerky motion, not a smooth, high frame rate.

1. Noll, A. M. (1992). Anatomy of a failure: Picturephone revisited. Telecommunications Policy, 16(4), 307-316.

Section: "Picturephone I System" and "Economic Considerations" (pp. 308-312). This article details the technical limitations, including the "small, coarse black-and-white image," and the prohibitive costs, stating the service was "very expensive" and required costly dedicated transmission lines, which were major factors in its commercial failure.

DOI: https://doi.org/10.1016/0308-5961(92)90032-U

2. Fischer, C. S. (1992). America Calling: A Social History of the Telephone to 1940. University of California Press.

Chapter 7: The Picturephone (in later editions or related works by the author on the topic). Fischer's historical analysis of telecommunications technology discusses the failure of early videophones, attributing it to the high price point for consumers and businesses, and the low quality of the video that did not justify the expense.

3. Cisco Press. (2015). CCNA Collaboration CICD 210-060 Official Cert Guide.

Chapter 1: Introduction to Voice and Video Collaboration. While focusing on modern systems, the historical context provided in introductory sections often acknowledges the limitations of earlier technologies. It notes that the evolution to modern IP-based systems was driven by the need to overcome the high costs of legacy PSTN and ISDN circuits and the poor quality of early video codecs. This implicitly supports that high cost and low quality were the problems to be solved.