Mobile radio data communication system and method

The method of operating a radio frequency data communication system wherein a multiplicity of mobile transceiver units are to collect data and are to be able to transmit the collected data promptly after its collection to a base transceiver station, during movement of the mobile transceiver units at varying distances from the base transceiver station and wherein reliable communication with such mobile transceiver units over the area of movement of the mobile transceiver units could only take place at a limited normal data rate, said method comprising:

• effecting RF wireless transmission of a first signal from the base transceiver station to the mobile transceiver units at an increased data rate substantially higher than the normal data rate,
• at respective mobile transceiver units which successfully receive said first signal, evaluating characteristics of the first signal which are predictive of successful communication of the respective mobile transceiver unit with the base transceiver station at a higher than normal data rate in spite of potential adverse transmission conditions,
• effecting RF wireless transmission of a second signal from the base transceiver station to the mobile transceiver units at a limited normal data rate,
• for less favorably situated mobile transceiver units which have collected data to send and which do not successfully receive the first signal or which do successfully receive the first signal but determine that transmission at a high data rate would be likely to be subject to detrimental transmission conditions, arranging to send the collected data to the base transceiver station at a limited normal data rate, and
• for more favorably situated mobile transceiver units which have collected data to send and which successfully receive the first signal and which determine that transmission conditions are not likely to prevent successful transmission at a high data rate, arranging to send the collected data at a high data rate substantially higher than the normal data rate.

The method of operating a radio frequency data communication system wherein a multiplicity of mobile transceiver units are to collect data and are to be able to transmit the collected data promptly after its collection to a base transceiver station, during movement of the mobile transceiver units at varying distances from the base transceiver station and wherein reliable communication with such mobile transceiver units over the entire area of mobile operation could only take place at a limited normal data rate, said method comprising:

• in a communications interchange between the base transceiver station and one or more mobile transceiver units, effecting with a RF wireless transmission, the transmission of a test signal in one communication direction via an RF link,
• at a receiver receiving the test signal, evaluating the characteristics of the test signal which are predictive of successful communication between a respective mobile transceiver unit and the base transceiver station at a higher than normal data rate in spite of potential adverse transmission conditions,
• if the evaluation of the received test signal determines that transmission at a high data rate would be likely to be subject to detrimental transmission conditions, transmitting a responsive RF wireless transmission in the opposite communication direction via said RF link signalling for further communications interchange at the limited normal data rate, and
• if the evaluation of the received test signal determines that transmission conditions are not likely to prevent successful transmission at a high data rate, transmitting a responsive RF wireless transmission in such opposite communication direction via said RF link signalling for further communications interchange at a higher data rate substantially higher than the limited normal data rate.

In a radio frequency data communication system,

• base station transceiver means selectively operable for data communication at a lower relatively conservative first data rate where reliable transmission is obtained under a relatively wide range of operating conditions, and at a relatively less conservative second data rate which is substantially higher than said first data rate and provides reliable data communication under a more restricted range of operating conditions,
• a plurality of mobile transceiver units in radio communication with said base station transceiver means and selectively operable for data communication at said first data rate and at said second data rate,
• control means evaluating a test transmission occurring between the base station transceiver means and at least one of said plurality of mobile transceiver units, and operable to evaluate said test transmission as received to determine the probable feasibility of data communication between said base station and said one of said plurality of mobile transceiver units at said relatively less conservative second data rate and selecting according to such evaluation said second data rate if evaluated as probably feasible and otherwise said lower relatively conservative first data rate, and
• data rate switchover means controlled by said control means for automatically effecting data communication at the first and second data rates according to the evaluation by said control means of the test transmission.

In a radio frequency data communication system wherein a multiplicity of mobile transceiver units are to collect data and are to transmit the collected data promptly after its collection to a base transceiver station and wherein reliable communication between such mobile transceiver units and said base transceiver station could occur at a limited data rate, the invention comprising

• a base transceiver station capable of transmitting data at a limited data rate and at an increased data rate, said base transceiver station selectively transmitting a first signal to the mobile transceiver units at the increased data rate,
• the mobile transceiver units evaluating the first signal from the base transceiver station to predict whether successful communication with the base transceiver station will occur at the increased data rate,
• said mobile transceiver units which predict successful communication with the base transceiver station at the increased data rate responding to said first signal at the increased data rate,
• said mobile transceiver units which fail to predict successful communication with the base transceiver station at the increased rate responding to said first signal at the limited data rate.

A radio frequency data communication system for transmission of data collected by a multiplicity of mobile transceiver units, to a base transceiver, comprising:

• a base transceiver selectively operable at a limited data rate and at an increased data rate
• the multiplicity of mobile transceiver units selectively operable at the limited data rate and at the increased data rate,
• said mobile transceiver units responsive to transmission by said base transceiver, and having control means therein to evaluate the feasibility of responding at said increased data rate,
• said base transceiver capable of determining which mobile transceiver units respond to the transmission of a polling signal transmitted at said increased data rate and allocating time slots for transmission to said mobile units which responded at the increased data rate,
• said base transceiver communicative at said increased data rate during said allocated time slots with said mobile transceiver units which respond at said increased data rate.