Patexia seeks prior art for a patent that allegedly describes a method of transmitting data between a sender (mobile station) to a receiver (base station) that uses hybrid ARQ (automatic repeat request) to ensure accurate data transfer. The system is notably able to modify the redundancy version of its retransmission based on the coding rate and the number of times the data has been retransmitted in order to make its process more efficient.

In order to transfer data, the system follows these steps:

• the sender initially transmits its data using a redundancy version that is fully self-decodable over an E-DCH (enhanced data channel) protocol
• if the data is transferred error free to the receiver, the receiver sends an acknowledge signal (ACK) to the sender
• if the data is not transferred error free to the receiver, the receiver sends a not acknowledge signal (NACK) back to the sender
• after receiving NACK, the sender retransmits the data using a different redundancy version
• the system then repeats the NACK-retransmit steps until the data is transferred error free

Notably, the method in the patent is able to modify the redundancy version used during retransmission by:

• using the coding rate to determine whether or not to use a redundancy version that is fully self-decodable or use a redundancy version that is only decodable when combined with the initial redundancy version
• using the number of retransmissions to select from a set of redundancy versions based on the data to be transferred and using an initial set of redundancy versions for the first number of retransmissions, and then only unlocking a second set of redundancy versions if the data continues to be transferred with errors

Figure 1. Block Diagram of the Data Redundancy Transmission System

Questions

1. Was the reference filed or published before September 15th, 2004? (True/False)
2. Does the reference describe a telecommunications device that transmits data packets to a receiving base station according to a hybrid automatic repeat request (ARQ) protocol to ensure data redundancy via an enhanced dedicated channel (E-DCH) data link?
3. Does the device’s first transmission of the data include a data packet that is formatted to a redundancy version that is fully self-decodable?
4. Upon receiving a confirmation from the base station that the data was incorrectly received, does the device’s retransmission of the data include a second data packet that is formatted with a different redundancy version?
5. Does the device select the redundancy version of the retransmitted data packet based on the coding rate, including a self-decodable redundancy version if the coding rate is below a predefined upper limit?

Bonus Questions

6. Does the device select the redundancy version of the retransmitted data packet based on the number of times the data has been retransmitted, using a particular set of redundancy versions for the first few retransmissions, then unlocking a second set of redundancy versions if the number of retransmissions goes past a predefined number?

Glossary

• Enhanced Dedicated Channel (E-DCH) - an uplink transmission format used by the High Speed Uplink Packet Access (HSUPA) 3G mobile telephony protocol
• Redundancy Version - a format of encoding data that includes the information to be transmitted plus set or sets of the same information included again in a redundant fashion to allow for error correction if the packet isn’t received accurately
• Coding Rate - the ratio of bits generated for each bit of information to be encoded. For example, a code rate of 1/3 would represent for every bit to be coded three coded bits are generated.