Terrorist Attack Report Finds Telecom Services Need Improving

A report into last years terrorist bombing attacks in London has called for more robust telecoms networks which can more reliably survive the huge surge in use that a major incident such as that caused. The new report from the UK's Home Office found that when the bombs exploded in London last year, there were incredible acts of bravery by the emergency services, volunteers, and members of the public - but there are still lessons to be learned.

The report shows that the emergency services responded efficiently, and under very difficult conditions. But it also sets out a number of areas where more could have been done, and details changes that should be made.

The report noted that, quite naturally the GSM networks do not have limitless capacity, but that the TETRA based radio system (branded Airwave) is being deployed with the emergency services so their reliance on conventional mobile phones should reduce.

The mobile networks have a voluntary network management scheme called ACCOLC that can be used to provide network access to privileged users with a special SIM card (while still allowing all users to make 999 calls). Such privileged access is only invoked under very special circumstances at the discretion of the network operator following a request by the police Gold commander, and then only for a specific network and limited geographic area for the shortest possible period of time.

The report confirms that the City of London Police did in fact ask O2 to invoke privileged access around Aldgate for around four hours to ease access to their mobile network for responders with the appropriate access rights. However, some responders, and the London Ambulance Service in particular, along with the general public were therefore deprived of access. This did lead to a vast amount of speculation on the day, and subsequently - about how the networks had coped with the surge in traffic and some confused reports that the phone networks were switched off to prevent further attacks.

Currently, there are some 37,000 registered users on the ACCOLC database. The report calls for increased awareness of this facility for emergency workers.

The mobile networks naturally, suffered severe congestion because the level of demand was much greater than usual and exceeded the extra margin of capacity (about 20% above the average daily peak) that is built into the networks for unforeseen demand.

The congestion was managed by the operators through the application of network calming measures such as "call gapping", which restricted access from the fixed networks onto the mobile networks - but without affecting 999 services - and by allowing more calls by reducing the quality of voice calls (half rate codex).

The report made some notes about radio access in the underground and made recommendations for improving compatibility between different radio systems used by the emergency services.

You can download the full report (32 pages, pdf document) from http://security.homeoffice.gov.uk"

Posted to the site on 26th September 2006