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
- Loss of infrastructure
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
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
3rd December 2004 •Region: UK •Type:
Article •Topic: Telecoms
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