Early detection of crises using radio traffic analysis

Robert H. Warren

rhwarren@uwaterloo.ca

March 22nd 2003

Introduction

No matter how much proactive planning is done Emergency Preparedness is fundamentally about reacting to unexpected situations. The delay between the triggering event and the notification to the responsible agencies puts the staff at a disadvantage as they attempt to catch up to a situation.
We propose to research the feasibility of a real-time system capable of providing an early warning of a developing crisis. This would be done by tracking the rate at which organizations use their local and national radio networks. Specifically, we concentrate on the decision algorithms required for such an application. The intent is to provide a warning order at an earlier stage than is possible through normal channels, and to do so in an automated, real-time and objective fashion.
In most situations a triggering event occurs which precipitates a crisis. As its occurrence is noticed by the local authorities and the scope of its consequences recognized, additional resources will be incrementally involved. However, this evolutionary process is not ideal for several reasons: (1) the information and expertise needed for sensible decisions may be initially unavailable, (2) requests for additional help or resources may get miscommunicated, and (3) response lag will occur as each new agency involved makes its own preparations and assessments.
Much has been written about the need to get the right information to the right person in a crisis. Even in an ideal situation, managing field communications is a major logistical problem. In an emergency the problem is compounded by stress-related mishaps and bad decisions made with miscommunicated information.
Organizations try to mitigate these errors by establishing communication channels, call-lists, procedures, and Memoranda of Understanding (MOU) with other organizations. Such measures have their own limitations as information can only be collected, analyzed and distributed up to a certain rate.

Proposal

To reduce the lag in the communication and assessment process, we propose to measure the rate of radio network traffic to provide a real-time warning of a crisis. Fire, rescue and law enforcement organizations are large users of such networks, as are maintenance, delivery, plant operations and private security firms.
The relationship between heavy telecommunication usage and a crisis is well-known: during the events of September 11, 2001, cellular call volume increased by 50% in the North-Eastern United States (versus a 30% increase on Mother's day) and wireless Internet traffic increased by 60% in New York City. ¹
Certain agencies have agreements that allow for the monitoring of one-another's radio networks for items of interest, which requires a trained communications watch. While anything beyond such agreements raises some legal and ethical issues, these do not necessarily apply to the traffic analysis proposed here.
This approach is functional while avoiding a number of privacy and regulatory issues as the analysis of the utilization rate does not require the reception of the signal per se. The contents of the messages are not analyzed, only the rate at which transmissions are made. This coupled with the available information on ownership of radio channels can be combined into an activity index for each organization within a certain general area. ² By correlating these indexes for different services, communication trends can be used to provide advance warnings of upcoming mobilizations.
That Fire Company B has been dispatched to a fire and that all of its frequencies are extremely busy is of limited interest. That activity at a local petrochemical plant has spiked and is subsequently followed by fire and ambulance traffic is of greater interest. It is reasonable to then assume that further help may be required, for example, to evacuate nearby homes. It may not be so in the end, but in the meantime a warning notice can be sent out to other appropriate agencies.
If all radio channels for the local police force are near-saturated at a location, something of importance is occurring there. Conversely, complete silence on all police radio nets is an indicator of serious trouble.
This analysis process can be automated and conveys quality information. It is immediate and sufficiently detailed for a decision to recall personnel and begin planning to be made.

Implementation

Because the project relies only on transmissions detection and not reception, its radio component is technically simple and the signals can be detected at a greater range. Developments in Digital Signal Processing in the last few years have made it possible to monitor large segments of the radio spectrum in real-time using mostly commercial off the shelf hardware.
The actual location of antennas, their type and specific coverage are issues that would be best decided during deployment. We expect that a small, low-maintenance, low-cost network of distributed nodes would provide effective results, even if opportunistically co-located.
What we propose to research is the information flow from the signal detector to the system user. The transmission "hits" from the radio networks will include modulation, frequency channel and possibly power/bearing information. The multiple radio transmission sources must be matched to their owner and then run through a decision algorithm to determine the stakeholders and the magnitude of the event.
Several historical and geographical databases are available to develop such decision algorithms. The actual data utilized for this analysis will be obtained from the Canadian disaster database, radio logs recorded by different emergency response organizations and if necessary field trials. ³ ⁴ Likewise, there exists a large body of literature on conventional traffic analysis, artificial intelligence, distributed databases and electromagnetic propagation. By using an amalgam of all of these methods, we believe that key relationships can be discovered which allow for the routing of the alert to the appropriate persons.

Conclusion

The scope of this research will limit itself to the information processing aspects of utilizing existing radio telecommunications networks to provide an early warning of crises. During the 1998 ice storm, cellular phone traffic increased by as much as 1000% with some carriers.⁵ While the nature of the crisis was in itself obvious, the method described above could possibly have been used to provide an earlier and reliable indicator of localized crisis.

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"Early detection of crises using radio traffic analysis"

Early detection of crises using radio traffic analysis

Footnotes

... City.¹: National Research Council, The Internet under Crisis Condition, The National Academies Press: Washington, D.C., 2003, pp. 37-28
... area.²: Interestingly, this also allow us to tap into the collective intelligence of bystanders, such as cell-phone users.
... trials.³: http://www.epc-pcc.gc.ca/disaster/cddb_e.pdf
... ⁴: Preliminary queries with persons involved with emergency communications indicate that a sizable amount of information is available on past events in a number of different formats. Whenever possible, information already in digital format would be preferable.
... carriers.⁵: http://www.wirelessweek.com/index.asp?layout=story&articleId=CA4548&stt=001

Rob Warren School of Computer Science University of Waterloo 2006-01-31