Apparatus and method for operating and constructing an optical TDM/TDMA system having enhanced range

Claim 1

An optical TDM/TDMA system comprising: central station means for emitting optical TDM signal blocks in a predetermined first transmission cycle of TDM signal blocks in a frame format and for receiving optical TDMA signal blocks; a plurality of subscriber-proximate, detached means, each disposed at a transmission distance from said central station means, for receiving said TDM signal blocks from said central station means in a reception cycle and for emitting said TDMA signal blocks in reply to said TDM signal blocks, said plurality of detached means collectively emitting said TDMA signal blocks in a second transmission cycle of said TDMA signal blocks in said frame format with each detached means emitting a signal block into said second transmission cycle at a position in said second transmission cycle dependent on the transmission distance of that detached means from said central station means, said plurality of detached means including at least two detached means respectively disposed at different transmission distances from said central station means; an optical branch network connecting said central station means to each detached means via which said TDM and TDMA signal blocks are transmitted; said central station means including means for defining an anticipation window for each detached means during which a TDMA signal from that detached means is expected to be present in said second transmission cycle; said plurality of detached means being divided into at least two range zones of respectively different transmission distances; all detached means in each range zone including delay means for delaying emission of a TDMA signal block from that detached means, following reception of a TDM signal block, by a delay dependent on the range zone, with all detached means in a range zone at a longest transmission distance having a first delay and all detached means respectively in other range zones having further respective delays longer than said first delay; and means for introducing a frame offset between said first and second transmission cycles equal to a duration of said anticipation window multiplied by the plurality of range zones decremented by one, and for initiating the second transmission cycle in reply to the first transmission cycle only after completion of said reception cycle.

Claim 5

A method for operating and constructing a TDM/TDMA system comprising the steps of: emitting optical TDM signal blocks in a predetermined first transmission cycle of TDM signal blocks in a frame format from a central station, and receiving optical TDMA signal blocks at said central station; receiving said TDM signal blocks collectively in a reception cycle in a plurality of subscriber-proximate, detached units each disposed at a distance from said central station; emitting a second transmission cycle of said TDMA signal blocks in said frame format collectively from said plurality of detached units in reply to said first transmission cycle with each detached unit emitting a signal block into said second transmission cycle at a position in said second transmission cycle dependent on the transmission distance of that detached unit from said central station; disposing at least two of said detached units at respectively different transmission distances from said central station; defining an anticipation window at said central station for each detached unit during which a TDMA signal from that detached unit is expected to be present in said second transmission cycle; dividing said plurality of detached units into at least two range zones of respectively different transmission distances; delaying emission of said TDMA signal block from each detached unit respectively in a range zone, following receipt of a TDM signal block, by a delay dependent on the range zone, with all detached units in a range zone at a largest transmission distance having a first delay and all detached units respectively in other range zones having respective further delays larger than said first delay; introducing a frame offset between said first and second transmission cycles equal to a duration of said anticipation window multiplied by the plurality of range zones decremented by one; and initiating said second transmission cycle in reply to said first transmission cycle only after completion of said reception cycle.

Claim 6

A method for operating and constructing a TDM/TDMA system comprising the steps of: emitting optical TDM signal blocks in a predetermined first transmission cycle of TDM signal blocks in a frame format from a central station, and receiving optical TDMA signal blocks at said central station; receiving said TDM signal blocks collectively in a reception cycle in a plurality of subscriber-proximate, detached units each disposed at a distance from said central station; emitting a second transmission cycle of said TDMA signal blocks in said frame format collectively from said plurality of detached units in reply to said first transmission cycle with each detached unit emitting a signal block into said second transmission cycle at a position in said second transmission cycle dependent on the transmission distance of that detached unit from said central station; disposing at least two of said detached units at respectively different transmission distances from said central station; defining an anticipation window at said central station for each detached unit during which a TDMA signal from that detached unit is expected to be present in said second transmission cycle; dividing said plurality of detached units into at least two range zones of respectively different transmission distances; delaying emission of said TDMA signal block from each detached unit respectively in a range zone, following receipt of a TDM signal block, by a delay dependent on the range zone, with all detached units in a range zone at a largest transmission distance having a first delay and all detached units respectively in other range zones having respective further delays larger than said first delay; introducing a frame offset between said first and second transmission cycles equal to a duration of said anticipation window multiplied by the plurality of range zones decremented by one; and initiating said second transmission cycle in reply to said first transmission cycle only after completion of said reception cycle.