The present invention provides a method (500), device (400), microprocessor (500) and microprocessor memory (400, 500, 600) for instantaneous preemption of packet-switched data from a user that has won contention for a channel and for transmitting on a time slot, by higher priority traffic ...http://www.google.com.hk/patents/US5734867?utm_source=gb-gplus-share專利 US5734867 - Method, device, microprocessor and microprocessor memory for instantaneous preemption of packet data 
