Method and apparatus for increasing the system efficiency of a TDMA system by reducing time slot guard time

A time division multiple access communications method in which a plurality of remote units communicate with a receiving station, the receiving station transmitting at least one downlink frame to each of said remote units, each of said remote units transmitting at least one uplink frame to said receiving station, comprising the steps of:

• sending a short data burst with a first guard time from at least one of said remote units to said receiving station;
• calculating a time differential at said receiving station between a reference time and a time at which said short data burst is received by said receiving station;
• sending a timing adjustment instruction from said receiving station to said remote unit based on the time differential;
• adjusting a transmitted timing reference at said remote unit based on the timing adjustment instruction;
• verifying the adjusted transmitted timing reference at said receiving station;
• and
• beginning a regular communication by sending a plurality of regular data bursts from said remote unit to said receiving station using said adjusted transmitted timing reference, said regular data bursts each respectively employing a second guard time which is shorter in duration than said first guard time.

A time division multiple access communications method in which a plurality of remote premises interface devices (PIDs) communicate with a headend receiving station, the headend receiving station transmitting at least one downlink frame to each of said PIDs, each of said PIDs transmitting at least one uplink frame to said headend receiving station, comprising the steps of:

• a. sending a short data burst from at least one of said PIDs to said headend receiving station;
• b. measuring a time difference at said headend receiving station between a reference time and a time when said short data burst is received by said headend receiving station;
• c. sending timing correction and adjustment information from said headend receiving station to said PID, said timing correction being derived from the time difference;
• d. adjusting a timing of a plurality of regular data bursts to be sent by said PID to said headend receiving station;
• and
• e. sending a trial message from said PID to said headend receiving station.