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How effective is mobile telephony in a crisis?

Get free weekly news by e-mailBy Harvey Fawcett


Many organisations rely on mobile telephones for day to day operations. The ubiquity and usefulness of mobile technology cannot be disputed. However, when an organisation suffers a crisis, can mobiles be relied upon? This article explores some pertinent issues in this area.


Elements of a communication system failure
There are two elements of communication system failure during a crisis:
- Loss of infrastructure
- Overload

Loss of infrastructure occurs where some, or all elements, of a system are lost to damage or other impacts (e.g. power blackouts) that result in total loss of access.

Overload occurs when usage peaks to a level where systems are unable to cope.
Both can be combined.

The 9/11 experience
There have been many instances both before and after the 9/11 attacks that provide information on how telecommunication networks perform under extremely high load. With or without infrastructure damage. However it is the effects on telecommunications during the New York attacks that have been most widely studied.

Because of the unprecedented scale of the attacks the impact on telecommunications systems was extremely severe. The attacks damaged significant amounts of physical infrastructure and demand for information and the means to communicate soared.

For example, the damage inflicted by the falling towers caused a complete failure at 140 West Street, a major telecommunications hub. 200,000 voice lines, 150,000 business lines, and the equivalent of about 4 million data circuits went out of commission. The emergency call system (911) switched immediately to a backup and remained operational, handling a call volume of approximately 38,000 or a 71 percent increase over normal activity. Other carriers were also affected. One Wireless communication service provider experienced a 1300 percent increase in traffic.

By 11am over 90 percent of mobile calls were being blocked in the NYC area due to a combination of infrastructure damage and overload. Power issues continued to affect service availability. Wireless communication systems did not however completely fail, and by the deployment of mobile cell sites with microwave backhaul capacity were more rapidly restored than fixed lines.

It has been widely reported that Short Message Service (text) and mobile e-mail devices such as Blackberries continued to work and in fact proved to be the most reliable means of communication in the immediate aftermath and medium term. Text messaging does not have anywhere near the popularity in the US as it does in the UK but several reports cite this as the one communications technology that continued to work throughout.

Switching off mobile networks during crises
Can the government switch off mobile networks in a crisis? The answer is ‘Yes, but its use is very limited’. All GSM networks can apply access control. There are 15 levels of access with 10-15 reserved for essential users such as the emergency services. In the UK Access Overload Control (ACCOLC) is a control programme which the cellular radio network providers have agreed to implement at the request of the police or Cabinet Office to ensure that, in an emergency, the public safety services and other relevant authorities will have priority access to cellular radio systems which might otherwise become congested by non-essential users.

The Police Incident Commander is normally the only authority permitted to invoke ACCOLC. Exceptionally, the Cabinet Office may assume this responsibility if the magnitude of the crisis demands central government intervention. ACCOLC is designed only to support the emergency services at the scene of a major incident.

The key factor that people often misunderstand is that ACCOLC can only be implemented on a cell by cell basis; it is not a wide area system. This means that the cell or cells that cover the area of the incident must first be identified before a request can be implemented.

The capacity of cellular systems is now such that ACCOLC is rarely needed and the implementation of systems such as Airwave, a digital trunked radio system for the police and other emergency services makes its invocation even less likely.

It is also likely that in a crisis many of an organisation’s staff will not be in the immediate area of an incident that requires ACCOLC because of exclusion zones and cordons.

What can organisations do?
The vast majority of business affecting incidents will not have any impact on the mobile networks so they remain a valid choice for organisations wishing to communicate in a crisis.

However, the experience drawn from the USA is that large scale incidents affecting both infrastructure and usage will significantly degrade performance of mobile networks. For UK readers this statement is balanced by the fact that mobile usage is considerably higher in the UK than the USA and therefore competition forces network operators to have high capacity and resilient networks.

Organisations should investigate alternative and complementary communication systems such as SMS and packet based store and forward technologies such as Blackberry and Mobitext platforms.

The key message is that no one single means of communication can ever be fully resilient but deploying a carefully balanced mix of technologies and providers will dramatically increase the chances of being able to successfully communicate in a crisis.

Harvey Fawcett is operations director of 247i Limited.

247i has developed 247i Messenger, a solution which combines the power of an Enterprise Class Notification Network with highly trained personnel operating in an IS017799 security management framework to deliver a comprehensive crisis notification service. ‘The 247i Crisis Notification Methodology’ is a collection of systems and procedures used to deliver secure, reliable, accurate, easy to use and above all else, effective, crisis notification.

For further information please contact Alan Lloyd +44 (0) 870 990 9816

Date: 3rd December 2004 •Region: UK •Type: Article •Topic: Telecoms continuity
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