“Telecommunication overload” is a commonly used term that is a regular feature of various emergency scenarios. However, one fact needs to be remembered. Although some copper carrier network pieces are still in place in the United States, nearly all new investment is going into fiber backbones and updated wireless services. Fiber networks are designed to handle extra capacity easily and wireless technology is advancing rapidly.
There is a fine line between reading after-action reports and preparing to fight a previous battle. People are still talking about the cellular telephone network overload observed just after the 1 August 2007 I-35W bridge collapse in Minneapolis. There was also an overload of cellular services in Boston, Massachusetts after the 13 April 2014 Marathon Bombing. However, the carriers were able to make some adjustments in each case to handle more load.
At the start of the 2020 COVID-19 lockdown, questions were raised about whether carrier/service provider networks would be able to handle the increased and changing load caused by the COVID-19 shift to working from home. There was a significant surge in the use of video conferencing services like Zoom. And the increase in work-from-home conference calls was certainly testing the capacity of cellular and landline telephone networks.
In May 2020, telecommunication carrier leaders released some figures. Traffic was up nearly a third in voice calls and data/internet services.
In general, the U.S. carrier networks were fine. The fact that response times to key applications and services such as Google and Amazon were normal was a good sign. Internet and network access can be hindered when small data units (i.e., packets) are unsuccessful in completing the send/receive process. Slow network response time is a fairly solid indication of such packet loss from network congestion and an overloaded network.
After several generations of new technical standards and a few hundred billion in investment, is telecommunication overload less likely?
Decades ago, microwave radio networks and copper coaxial cable networks crisscrossed the country. Telephone wires were actual wires and undersea cables to places like the United Kingdom and Europe were copper. An iconic invention around 1960, T-carrier and T1, allowed over a million bits per second of data or up to 24 telephone calls to travel reasonable distances over two pairs of copper wire. The network T1 service was designed to be (and was) over 99.7% reliable.
In modern times, this reliability and solid engineering turned out to be a problem. In the face of vast increases in data rates and changing call patterns (such as the cellphone), many T1 users (including carriers) were reluctant to get rid of them. Nevertheless, the current demand for data transmissions is far beyond the capabilities of the T1. If a T1 was full, a new one would need to be installed, which was normally a 30-day process. With copper wire’s fairly poor handling of higher data rates over long distances, telecommunication carriers are trying to phase out legacy copper services.
Fiber optic technologies are now widely used. Over a fiber optic cable, made of strands of glass or plastic, wavelength-division multiplexing can be used to add more colors of light to carry more data, and carriers can light up unused fiber strands to add capacity. So, if there were a traffic spike, say during a pandemic, carriers could fairly easily add capacity in the fiber network.
Vast capital has been deployed (and is still needed) to install fiber networks. The need for more investment is fiber is widely known, often in the context of rural broadband projects.
The transmission of voice is also changing. Analog voice technology was common for home phones, which could generally use one pair of wires. These wires would connect, for example, the copper plant to the local central office a few miles away. Calls were multiplexed onto a T1 and sent over the network.
Currently, voice over IP technology is taking over, albeit more slowly than expected. Calls are converted to data traffic using a technology called a CODEC (Coder Decoder). A common one in modern cellular/LTE networks is adaptive multi-rate audio CODEC. This requires less than 40 or so kilobits of bandwidth per call, including overhead.
In addition, many cell sites are being upgraded to support 5G, with a minimum speed of over 50 megabits. More than 100 megabits is more common, usually with fiber pulled to the cell site, and sometimes microwave. A fiber-fed cell site can then handle many calls. Prioritization systems have been developed to manage priority site data and voice use, with voice as the top priority followed by levels and types of data users.
Cell sites for data services (like LTE or 5G) can also utilize traffic prioritization. For example, after voice calls, a public safety official who needs a building drawing would be able to obtain priority over the crowd of bystanders at a fire scene streaming live over the Internet.
Hackers, malicious attacks, and misconfiguration can still cause circuit overloads. Very long power outages can strain fuel distribution to generators. However, the fiber is there, and the newer wireless standards are as well.
COVID-19 tested the durability of modern telecommunications systems and, in general, the systems passed the test. For public service agencies and emergency responders, this is promising. Unless a local cell tower is toppled by wind or flooded by storm surge, it is likely to be operable during an emergency. If an organization or agency needs or is eligible for prioritization services, those are often available as well. Although ongoing technological developments are needed to meet or exceed the growing demand for voice and data services, the fear of telecommunication overload tends to be greater than the actual threat – at least for now.