Dual mode satellite/cellular terminal

Claim 2

A time division multiple access format for transmitting traffic and signalling data between a network station and a plurality of remote stations, comprising the steps of: dividing a superframe period into an odd number of TDMA frame periods; dividing each TDMA frame period into an even number of timeslots; using said even number of timeslots in one of said odd number of TDMA frames for transmitting signalling information addressed respectively to a corresponding even number of remote stations and the remaining TDMA frames in said superframe for transmitting traffic information; dividing said remaining number of frames used for transmitting traffic information into a first group of traffic frames and a second group of traffic frames; and using said even number of timeslots in said first group of traffic frames to transmit traffic data to a corresponding even number of remote stations and using the timeslots in said second group of traffic frames to transmit data to a corresponding number of other remote stations.

Claim 3

A method according to claim 1, wherein said signalling information comprises an indication whether said information is addressed to one of said remote stations for which traffic information was transmitted using a timeslot from each of said first group of traffic frames or for one of said remote stations for which traffic information was sent using a timeslot in said second group of traffic frames.

Claim 4

An adaptive time division multiple access format for transmitting traffic and signalling data between a network station and a plurality of remote stations, comprising the steps of: dividing a superframe period into an odd number of TDMA frame periods; dividing each TDMA frame period into an even number of timeslots; using said even number of timeslots in one of said odd number of TDMA frames for transmitting signalling information to said remote stations and the remaining TDMA frames in said superframe for transmitting traffic information; dividing said remaining number of frames used for transmitting traffic information into a first group of traffic frames and a second group of traffic frames; and using one of said even number of timeslots in said first group of traffic frames to transmit traffic data to a first of said remote stations and using the corresponding timeslot in said second group of traffic frames to transmit data to another remote station alternatively in dependence on communications signal quality using both said timeslot in said first group of frames and said corresponding timeslot in said second group of frames for communicating with the same remote station.

Claim 5

An adaptive time division multiple access format for transmitting traffic and signalling data between a network station and a plurality of remote stations, comprising the steps of: dividing a superframe period into an odd number of TDMA frame periods; dividing each TDMA frame period into an even number of timeslots; using said even number of timeslots in one of said odd number of TDMA frames for transmitting signalling information to said remote stations and the remaining TDMA frames in said superframe for transmitting traffic information; dividing said remaining number of frames used for transmitting traffic information into a first group of traffic frames and a second group of traffic frames; and using one of said even number of timeslots in said first group of traffic frames to transmit traffic data to a first of said remote stations and using the corresponding timeslot in said second group of traffic frames to transmit data to another remote station alternatively in dependence on communications signal quality using both said timeslot in said first group of frames and said corresponding timeslot in said second group of frames for communicating with the same remote station.

Claim 6

An improved method of capacity allocation in a TDMA satellite or cellular communications system comprising a number of areas containing mobile subscriber terminals each area being served by a respective antenna beam, said method comprising the steps of: allocating each mobile terminal in each area a timeslot in a each TDMA frame period and a channel frequency in a frequency set for receiving data whereby mobiles in the same area receive different timeslot and frequency allocations and mobiles in different areas may share the same timeslot and frequency allocation; transmitting coded information bits to a mobile terminal in a given area using a respectively allocated timeslot in every one of said TDMA frame periods when the total number of mobiles so served in said given area is similar to the number of mobiles served in surrounding areas and close to a mean number of mobiles expected in each area; and transmitting coded information bits to a mobile terminal in a given area using a respectively allocated timeslot in every alternate one of said TDMA frame periods and using the corresponding timeslot in the other half of the frame periods for transmitting coded information to a different mobile terminal when the number of mobiles so served in said given area is substantially greater than said mean value and the number of mobiles served in adjacent areas is on average less than said mean value.

Claim 7

An improved method of capacity allocation in a TDMA satellite or cellular communications system comprising a number of areas containing mobile subscriber terminals each area being served by a respective antenna beam, said method comprising the steps of: allocating each mobile terminal in each area a timeslot in a each TDMA frame period and a channel frequency in a frequency set for receiving data whereby mobiles in the same area receive different timeslot and frequency allocations and mobiles in different areas may share the same timeslot and frequency allocation; transmitting coded information bits to a mobile terminal in a given area using a respectively allocated timeslot in every one of said TDMA frame periods when the total number of mobiles so served in said given area is similar to the number of mobiles served in surrounding areas and close to a mean number of mobiles expected in each area; and transmitting coded information bits to a mobile terminal in a given area using a respectively allocated timeslot in every alternate one of said TDMA frame periods and using the corresponding timeslot in the other half of the frame periods for transmitting coded information to a different mobile terminal when the number of mobiles so served in said given area is substantially greater than said mean value and the number of mobiles served in adjacent areas is on average less than said mean value.