Method and apparatus for distinguishing between a digital control channel and a digital traffic channel in a radiocommunication system

A method for locating a digital control channel among a plurality of channels comprising the steps of:

• grouping said plurality of channels into a plurality of blocks;
• ranking each of said blocks based upon a relative likelihood of finding said control channel therein;
• reading channels within a highest ranked block to locate a digital channel;
• obtaining, if said digital channel is a digital traffic channel, location information pointing toward a digital control channel;
• and
• using said location information to locate said digital control channel.

A method of broadcasting digital traffic channels and digital control channels comprising the steps of:

• broadcasting, from a base station, digital traffic channels including coded digital verification color code (CDVCC) fields and digital control channels including coded superframe chase (CSFP) fields;
• including, in said CDVCC fields, first check bits;
• providing, in said CSFP fields, second check bits;
• and
• wherein said first and second check bits are inverted relative to one another.

A method for distinguishing between a digital traffic channel and a digital control channel in a mobile station comprising the steps of:

• receiving and decoding a field in a channel which has been broadcast over an air interface , said field having a primary purpose which is different than distinguishing between a digital traffic channel and a digital control channel;
• determining if error correction bits in said field are inverted relative to a predetermined set of error correction bits;
• and
• identifying said channel as a digital traffic channel or as a digital control channel based upon said step of determining.

A base station comprising:

• a transmitter for broadcasting digital traffic channels and digital control channels;
• a processor for including coded digital verification color code (CDVCC) fields in said digital traffic channels and coded superframe phase (CSFP) fields in said digital control channels;
• said processor also including, in said CDVCC fields, first check bits;
• said processor also providing, in said CSFP fields, second check bits;
• and
• wherein said first and second check bits are inverted relative to one another.

A mobile station comprising:

• means for receiving and decoding a field, said field having a primary purpose which is different than distinguishing between a digital traffic channel and a digital control channel in a channel which has been broadcast over an air interface;
• a processor for determining if error correction bits in said field are inverted relative to a predetermined set of error correction bits;
• and
• wherein said processor identifies said channel as a digital traffic channel or as a digital control channel based upon said determination.

A base station comprising:

• a transmitter for broadcasting a digital traffic channel and a digital control channel using timeslots;
• a processor for including a coded digital verification color code (CDVCC) field in said digital traffic channel and a coded superframe phase (CSFP) field in said digital control channel;
• and
• wherein a value of said CDVCC fields remains fixed from timeslot to timeslot while a value of said CSFP fields varies from timeslot to timeslot.