Method and apparatus for direct communication in a TDMA radio communication system
AssigneeInternational Business Machines Corporation
InventorsTrieu C. Chieu, Anand Narasimhan, Gary E. O'Neil, Li-Cheng R. Zai
Life of this patent
Estimating the term…
Abstract
Direct communication between a primary portable unit initiating the communication and a secondary portable unit is established utilizing two handshaking operations. The first handshaking operation is performed in the base station channel to establish initial contact between the primary and secondary portable units. After initial contact is made, the second handshaking operation is performed to establish communication in an unoccupied channel. The base station channel and the unoccupied channel may be a TDMA/TDD channel or a TDMA/FDD channel.
Claims56
In a communication system wherein communication between a base station and user stations occurs over a plurality of radio channels each having time slots, a method for establishing direct communication between user stations comprising the steps of:
- controlling a first user station to locate a first radio channel within said plurality of radio channels wherein communication of data signals and control signals occurs between said base station and at least one user station,
- synchronizing said first user station with a first predetermined period of time within said first radio channel during which said base station is not transmitting data and not receiving data;
- and
- controlling said first user station to transmit a first calling signal during said first predetermined period of time within said first radio channel to establish direct communication between said first user station and a second user station.
An apparatus for use in a communication system wherein communication between a base station and user stations occurs over a plurality of radio channels each having time slots, the apparatus comprising:
- means for locating a first radio channel within said plurality of radio channels wherein communication of data signals and control signals occurs between said base station and at least one user station,
- means for synchronizing with a first predetermined period of time within said first radio channel during which said base station is not transmitting data and not receiving data;
- and
- means for transmitting a first calling signal during said first predetermined period of time within said first radio channel.
An apparatus for use in a communication system wherein communication between a base station and user stations occurs over a plurality of radio channels each having time slots, wherein communication of data signals and control signals from said base station to said at least one user station occurs within a first radio channel having a first frequency, wherein communication of data signals and control signals from said at least one user station to said base station occurs within a second radio channel having a second frequency different than said first frequency, the apparatus comprising:
- means for locating said first radio channel;
- means for synchronizing with a first predetermined period of time within said first radio channel during which said base station is not transmitting data and not receiving data;
- and
- means for transmitting a first calling signal during said first predetermined period of time within said first radio channel.
Dependencies are inferred from the claim text.