Flexible two-way telecommunication system

Claim 3

A method as claimed in claim 1 , wherein said estimating step includes selecting said modulation and coding schemes on the basis of at least one of the following: received signal strength indication; bit rate; bit error rate; and end-to-end delay.

Claim 4

A method as claimed in claim 1 , wherein said transmitting step includes downlink transmissions that comprise time frames, where each time frame includes a header having indicia indicating the transmission characteristics and timing of each data burst in the time frame.

Claim 5

A method as claimed in claim 1 , wherein said transmitting step includes downlink transmissions that are TDMA.

Claim 6

A method as claimed in claim 1 , wherein said receiving step includes uplink transmissions that are CDMA and/or TDMA.

Claim 7

A two-way telecommunication system including a primary station and at least one secondary station, each station capable of receiving and transmitting signals, said system comprising: a) means at said primary station for receiving first signals one or more secondary stations on an uplink; b) means for estimating the quality of each of said received first signals at said primary station; c) means for individually selecting modulation and coding schemes at said primary station in accordance with said estimated first signals received on said uplink for each of said secondary stations; d) means for modulating second signals according to selected modulation and coding schemes for each of said secondary stations; and e) means at said primary station for transmitting said selectively modulated and coded second signals to each of said secondary stations on a single downlink frame, said downlink frame including a frame structure having a header for said frame and a data burst for each modulated second signal for each secondary station, said header providing information enabling each secondary station to locate its respective data burst within the frame structure.

Claim 8

A two-way telecommunication system including a primary station and at least one secondary station, each station capable of receiving and transmitting signals, said system comprising: a) means at said primary station for receiving first signals one or more secondary stations on an uplink; b) means for estimating the quality of each of said received first signals at said primary station; c) means for individually selecting modulation and coding schemes at said primary station in accordance with said estimated first signals received on said uplink for each of said secondary stations; d) means for modulating second signals according to selected modulation and coding schemes for each of said secondary stations; and e) means at said primary station for transmitting said selectively modulated and coded second signals to each of said secondary stations on a single downlink frame, said downlink frame including a frame structure having a header for said frame and a data burst for each modulated second signal for each secondary station, said header providing information enabling each secondary station to locate its respective data burst within the frame structure.

Claim 9

A system as claimed in claim 6 , characterized in that the primary station transmits downlink signals in accordance with a TDMA format comprising a succession of time frame structures, each including said frame header.

Claim 10

A system as claimed in claim 7 , characterized in that the frame header includes indicia indicating the location of data bursts intended for one or more of the secondary stations.

Claim 11

A system as claimed in claim 8 , characterized in that the frame header includes indicia indicating the format and timing of each data burst.

Claim 12

A system as claimed in claim 8 , characterized in that training sequences are embedded in data bursts.

Claim 13

A system as claimed in claim 7 , characterized in that at least one secondary station effects power saving by adopting a sleep mode whenever the secondary station determined that data bursts are directed to other secondary stations.

Claim 14

A system as claimed in claim 7 , characterized in that the time frames are of a substantially fixed duration.

Claim 15

A system as claimed in claim 6 , characterized in that the modulating means applies a high order modulation scheme to signals to be transmitted to secondary stations relatively close to the primary station and low bit rate orthogonal codes when transmitting signals to relatively distant secondary stations.

Claim 16

A system as claimed in claim 6 , characterized in that traffic data is transmitted on the downlink with a modulation scheme and power level determined to ensure reliable receipt by a secondary station.

Claim 17

A system as claimed in claim 6 , characterized in that uplink signals are transmitted as CDMA signals.

Claim 18

A system as claimed in claim 6 , characterized in that uplink signals are transmitted in accordance with a TDMA format.

Claim 19

A system as claimed in claim 16 , characterized in that TDMA uplink signals comprise at least two data bursts and in that a guard space is provided between adjacent data bursts.

Claim 20

A system as claimed in claim 16 , characterized in that TDMA uplink signals comprise at least two data bursts, and that each data burst comprises at least one training sequence.

Claim 21

A system as claimed in claim 16 , characterized in that TDMA uplink signals comprise data packets, and in that the bit rates of at least two of the data packets are different.

Claim 22

A system as claimed in claim 6 , characterized in that timing for uplink signals is derived from the downlink signals.

Claim 23

A system as claimed in claim 6 , characterized in that the system is a cellular system comprising a plurality of cells, each cell having a primary station definition a respective coverage area.

Claim 24

A system as claimed in claim 21 , characterized in that primary stations have means for handing over a secondary station participating in a call from one cell to another cell.