When You Have No Bars
On Thursday, February 22, 2024, many Americans woke up to poor or nonexistent cellphone service. We later learned that a major cellular service provider experienced a failure during a network update. The cascading effects of this failure caused a widespread outage that affected thousands of individuals, businesses, local governments, and first responders. As the day progressed, the carrier released some details to the public to assuage concerns, and service was eventually restored.
Cellular networks rely on multiple base stations or towers across an area to create network coverage. If a user exits the area of one cell, the nearest base station picks up their signal to maintain coverage. Most inhabited areas have multiple base stations; the higher the population density, the more likely there are to be additional stations to accommodate service load.
To prevent service disruption when networks are updated or upgraded, the updates tend to be passed from base station to base station along the network during times of lower service usage. Generally, this is a positive thing because most cellular base stations have varying degrees of coverage range so if one were to go down, the surrounding stations could take its place until it comes back online. This provides a robust and redundant communication infrastructure for customers. Unfortunately, if multiple base stations in an area go down, fail in a cascade, or are overloaded with traffic, service can be partially or completely disrupted.
There are several strategies that businesses and other organizations can use to minimize disruption when the service bars drop or the dreaded “no service” notification appears.
These include leveraging secure WIFI networks for WIFI calling, maintaining at least one landline, and maintaining pagers for immediate or emergency communication among key team members.
For situations requiring continuous communication, key personnel could use satellite phones to stay connected and send brief messages to pager users.
Pagers operate on different frequencies than cellular phones and allow for basic messaging services for key communications. Note that pagers are not encrypted and should not be used for communications where security is essential. For situations requiring continuous communication, key personnel could use satellite phones to stay connected and send brief messages to pager users.
Businesses and other organizations could also use multiple carriers for different devices for failover in case one network goes down, and maintain a Commercial Band (CB) radio at each office site to ensure communication with authorities and first responders should traditional telecommunication networks fail. Other options include deploying a mesh network throughout business and peer sites, as well as using LoRa/LoRaWAN-based devices for simple non-voice communication and location coordination.
First responders and local governments can mitigate the effects of lost service by leveraging alternative communication strategies similar to the business approach described above. In addition, take-home radios or pagers should be provided to individual first responders or other essential personnel to help to ensure that team members can be reached in case of network failure. In the event of cellular network outage, first responders are encouraged to actively monitor public emergency radio channels with trained personnel and have telephone operators cross-trained on radio communication.
At Leviathan Security Group, we have extensive experience testing baseband, experimental cellular infrastructure, and cellular devices.
Want to talk more about your organization’s readiness when you have no bars? Contact us!
Credits
This article was written in collaboration between:
Martin Bogomolni - Senior Hardware Security Consultant - LinkedIn Profile
Tom Overbey - Security Risk Advisor - LinkedIn Profile
Tom Pieragastini - Senior Security Consultant - LinkedIn Profile
