SYSTEMS AND METHODS FOR RANDOM ACCESS IN TIME DIVISION MULTIPLE ACCESS SATELLITE RADIOTELEPHONE COMMUNICATIONS

摘要

In a time division mutiple access (TDMA) satellite ra-diatelephone communications system, a radiotelephone communi-cates random access channel radiotelephone communications sig-nals to a satellite over a dedicated random access channel uplinkcarrier frequency band. In response, a time division mutiple ac-cess channel on a time division multiplexed uplink carrier fre-quency band different from the dedicated random access channeluplink carrier frequency band is assigned. The radiotelephonecommunicates time division multiplexed radiotelephone commu-nications signals to the satellite over the allocated time divisionmultiple access channel. Random access channel radiotelephonecommunications signals may be communicated to the satellitefrom a first radiotelephone over a first dedicated random accesschannel uplink carrier frequency band or from a second radiotele-phone over a second dedicated random access channel uplink car-rier frequency band different from said first dedicated random ac-cess channel uplink carrier frequency band. For a system in whichthe satellite communicates radiotelephone communications signalsto radiotelephones located in a first coverage area and communi-cates radiotelephone communications signals to radiotelephoneslocated in a second coverage area, random access channel ra-diotelephone communications signals may be communicated overa first dedicated random access uplink carrier frequency band ifthe radiotelephone is located in the first coverage area commu-nicating random access radiotelephone communications signalsover a second dedicated random access channel uplink carrierfrequency band different from the first dedicated random accessuplink carrier band if the radiotelephone is located in the second coverage area.