求翻译：随着信息社会的到来，人们希望现代信息传输网络能快速、经济、有效地提供各种电路和业务，而上述网络技术由于其业务的单调性，扩展的复杂性，带宽的局限性，仅在原有框架内修改或完善已无济于事， 此时SDH的产生并凭借其众多特性，使其在广域网领域和专用网领域得到了巨大的发展。是什么意思？

With the advent of information society, people want modern information transmission network to quickly and cost-effectively provide a variety of circuits and services, and the business of networking technology because of its monotony, extension complexity, bandwidth limitations, only the original Th

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