O2's UK Network Crash Hits Offender Monitoring System

judgecorp writes "Mobile operator O2's network crashed on Wednesday and Thursday of this week. In the aftermath it has emerged how other services rely on mobile networks. Law enforcement agencies were unable to track some convicted criminals wearing electronic tags, and the crash also disabled parts of London's network of 'Boris Bikes' — public hire bikes."

Re:Why not roaming?

[Igloodude]

Because the roaming network passes the authentication request to the home network HLR - so if the home network HLR is down, the roaming network doesn't know if the SIM can be allowed on its network.