Telecommunication system vulnerabilities to space-weather events

Many legacy telecommunication systems have intrinsic vulnerabilities, and modern systems that use the earth-space path can also suffer impairments as a result of variability in the distribution of ions and electrons within the ionosphere and plasmasphere. It has long been established that solar phenomena (e.g., flares, energetic particle events, CMEs, and related events) can play a significant role in the distribution of the free electron distribution, and this is critical in the propagation of radio waves, and the resultant performance of radio wave systems. With the growth in environmental monitoring and data assimilation technologies (i.e., GAIM), and with the improved speed of data access and timely dissemination of assessment and forecasting products, telecommunication systems can operate in an environment that may be characterized over several time regimes: present, near-term, and long-term. The accuracy of the characterizations is dependent upon the efficacy of models employed, as well as the accuracy of the data that drives the models. Certain adaptive telecommunication systems can respond to media variability through use of organic compensation schemes or systematic countermeasures (and these are usually referred to as self-contained robust systems), but generally it is more cost effective to incorporate non-organic forecasting schemes to "steer" the system parameters so that optimal operation can be achieved. For the latter category of systems, space-weather monitoring and forecasting is not only useful, it is an imperative.

This paper starts with a general review of telecommunication systems and their vulnerabilities. Then, specific examples are given for specified super-storms observed during the declining phase of the current solar cycle. A more general exposition can be found in a recent book by the author. In the present paper we discuss practical approaches for impairment mitigation in selected systems such as HF data link and voice communications used by commercial carriers and military air transport applications. These systems suffer significant performance impairment as the result of geomagnetic storms, and they also benefit the most from the incorporation of space-weather data for optimization of system parameters. We conclude with the benefits of space-weather information for a hierarchy of systems.