Patent ID: 6275481
Filing Date: 2001-08-14
Classification: H04W

Abstract:
A method for setting up an emergency call in a wireless local loop, in which subscriber terminal units (TU) are connected over a wireless link via a base station (BS) to an access node (AN) and further from the access node to a local exchange (LE) via a standard V5.2 interface, in which, when the interface is congested and a subscriber (TU) connected to the access node (AN) is attempting to make an emergency call to a public emergency number, a call control system of the local exchange (LE) is unable to find a free time slot for the setup of the emergency call within a predetermined period of time t1, wherein:a message indicating failure of an attempt to set up an emergency call is given by a V5.2 interface signalling program to a process responsible for the setup of the emergency call;via the process responsible for the setup of the emergency call, a message indicating failure of an attempt to set up the emergency call is given to a higher-level process responsible for signalling;call setup requests for other than emergency calls over the V5.2 interface are disabled during a predetermined period of time t2; andattempts to reserve a time slot in the V5.2 interface for the emergency call are repeated during said predetermined period of time t2.