Providing Emergency Services in Internet

During emergencies, service agencies rely on telecommunications to achieve quick response times and minimize loss of life and property. The existing public and government-based telephone systems provide three essential communication services: an emergency calling system, which the public uses to report problems and ask for help; emergency communications, which allow for crisis communications within agencies and between agencies and the public; and emergency alerting, which provides a channel for government agencies to notify the public when disasters occur. As we transition to a packet-switched infrastructure, we must reconsider how to provide these services. Internet-based communications offer new challenges, as old assumptions about trust, operation, and terminal location no longer hold. However, IPbased emergency services will also offer expanded services, more resilient networks, and faster response times. About half a dozen companies are offering commercial voice-over-IP services at this time, for both commercial and residential customers. It appears likely that the transition to an all-IP phone service will be slow, as depreciation intervals for switches are measured in decades. However, third-generation wireless systems (3G) are scheduled to offer packet voice services by 2005, adding possibly hundreds of millions of such devices to the network. As the “Emergency Communications” sidebar describes, the existing Internet architecture must be modified in two areas to support coordinated communication services. Here, however, our primary focus is on emergency calling and notification. In this article, we describe the components of the existing emergency calling and notification systems and our proposed IPbased architectures,1 each of which uses the session initiation protocol (SIP) as the signaling framework.2