Methods of dynamically switching return channel transmissions of time-division multiple-access (TDMA) communication systems between signaling burst transmissions and message transmissions

• US 6,407,986 B1
• Filed: 01/20/1999
• Issued: 06/18/2002
• Est. Priority Date: 09/30/1996
• Status: Expired due to Fees

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: Mobile Satellite Venture LP
• Inventors: Dutta, Santanu
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US09/233,067
• Time in Patent Office: 1,245 Days
• Field of Search: 370/280, 370/321, 370/329, 370/337, 370/341, 370/347, 370/349, 370/350, 370/442, 370/465, 370/468, 370/470, 370/503, 370/522, 455/450, 455/453, 455/507, 455/509, 455/511, 455/515, 455/517, 455/67.1
• US Class Current: 370/280
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system

Abstract

A method of communicating on at least one channel group of a communication system provides improved data transfer efficiencies over conventional systems by using discrete transfer rates. The channel group is includes at least one forward channel for channeling data transmitted from a central station to a plurality of terminals. At least one return channel is included for channeling transmissions by any of the plurality of terminals to the central station. Changes in the discrete data transfer rate are optionally accompanied by a change in a slot timing rate based on a frame transmission rate used over the forward channel. The method also allows the assignment of a predetermined number of return channel slots for a transmit frame for at least one combination of forward and return channels having prescribed forward and return data rates.

Claims

1. A method of communicating on at least one channel group of a communication system, the channel group having at least one forward channel and at least one return channel, wherein a central station transmits data over said forward channel of the channel group to a plurality of terminals, and transmissions by any of the plurality of terminals to the central station on any one of the at least one return channel of the channel group, the method comprising the step of communicating over at least one of the at least one forward channel and the at least one return channel of the at least one channel group using a range of discrete data transfer rates, wherein a change in the discrete data transfer rate is optionally accompanied by a change in a slot timing rate based on a frame transmission rate used over the forward channel.

2. A method according to claim 1, wherein said communicating step further comprises the step of communicating over at least one of the at least one forward channel and the at least one return channel of the at least one channel group using a range of discrete data transfer rates, wherein a change in the discrete data transfer rate is optionally accompanied by a change in a slot timing rate based on a frame transmission rate used over the forward channel, wherein a change in the discrete data transfer rate is optionally accompanied by a change in a slot timing rate based on a frame transmission rate used over the forward channel, and wherein the slot timing rate of the return channel is selected such that the return channel slots have a data capacity sufficient to accept information packets containing code symbols.

3. A method of communicating on at least one channel group of a communication system, the channel group having at least one forward channel and at least one return channel, wherein a central station transmits data over said forward channel of the channel group to a plurality of terminals at a forward data rate, and transmissions by any of the plurality of terminals to the central station on any one of the at least one return channel of the channel group at a return data rate, the method comprising the step of assigning a predetermined number of return channel slots for a transmit frame for at least one combination of the at least one forward channel and the at least one return channel having the forward and return data rates, the transmit frame used to synchronize return channel transmissions by the plurality of mobile terminals.

4. A method according to claim 3, wherein said assigning step further comprises the step of assigning the predetermined number of the return channel slots for the transmit frame for the at least one combination of the at least one forward channel and the at least one return channel having the forward and return data rates with different combinations of the forward and the return data rates.

5. A method according to claim 3, wherein said assigning step further comprises the step of assigning the predetermined number of the return channel slots for the transmit frame for the at least one combination of the at least one forward channel and the at least one return channel having the forward and return data rates, responsive to the forward and the return data rates.

6. A method according to claim 3, wherein said assigning step further comprises the step of assigning the predetermined number of the return channel slots for the transmit frame for the at least one combination of the at least one forward channel and the at least one return channel having the forward and return data rates, wherein 8 combinations of forward and return channels frequencies are available.

7. A method according to claim 3, wherein said assigning step further comprises the step of assigning the predetermined number of the return channel slots for the transmit frame for the at least one combination of the at least one forward channel and the at least one return channel having the forward and return data rates, based on the return channel data rate and a return channel transmit frame length.

8. A method according to claim 3, wherein said assigning step further comprises the step of assigning the predetermined number of the return channel slots for the transmit frame for the at least one combination of the at least one forward channel and the at least one return channel having the forward and return data rates, wherein each transmit frame contains an assigned number of return channel slots during which data may be transmitted by a designated one of the terminals.