Patexia seeks prior art for US Patents 7,230,908 (US ‘908) and 7,684,368 (US ‘368), with a focus on claims 1, 10, 12, 19, 21, and 23 of US ‘908, and claims 1, 8, 12, and 19 of US ‘368. The patents allegedly describe a satellite transmission system that uses frequency division multiplexing (FDM) or orthogonal frequency division multiplexing (OFDM) to transmit information to multiple receivers. The system is further described as being able to dynamically modify its transmission based on link conditions, sufficient frequency capacity, and available time slots. The system accomplishes this by using a main (broadcast) channel frequency to transmit data to all receivers, while selecting a specific frequency channel in order to communicate with a specific receiver.

In order to establish a stable downlink between the satellite and one or more receivers, the system is able to modify its broadcast in one or all of the following ways:

• receive link information identifying environmental or other link conditions that can affect its transmissions
• modify the modulation and coding format of the transmission in response to link  conditions and broadcast as channel information to the receiver(s)
• maintain carrier and timing synchronization between the transmitter and the receiver(s)
• scan the frequency spectrum and identify channels with sufficient capacity
• assign a channel with sufficient capacity to a specific receiver to establish a downlink
• assign a time slot to a specific receiver to establish a downlink

Additionally, the system formats its data frame in order to maximize broadcast efficiency, to communicate to the receivers all the actions taken to establish a stable downlink, and to allow each receiver to download data packets that are intended for that receiver as well as download and pass on data intended for other receivers.

Figure 1. Diagram of a transmission data frame

Questions

1. Was the reference filed or published before July 24th, 2000? (True/False)
2. Does the reference describe a system where a transmitter broadcasts data to multiple receiver systems via frequency division multiplexing (FDM) using one main channel frequency to broadcast data to all the receivers and alternate channel frequencies to transmit information to a specific receiver? (15 points)
3. Is the system further able to format its broadcasted data via orthogonal frequency division multiplexing (OFDM)? (10 points)
4. Does the system detect downlink conditions, modify the modulation and coding format of the transmission, transmit the results as channel information, and maintain carrier and timing synchronization with the receivers? (25 points)
5. In order to establish a downlink between the transmitter and a receiver, does the system scan for and assign an alternate channel frequency with available capacity, as well as dynamically assign a time slot? (25 points)
6. Does the system format its data frame with a slot including a first field specifying the modulation and coding format, and a second field identifying a next time slot in a subsequent frame for the receiver to receive a subsequent data packet; and one or more additional slots for data packets with address(es) to identify intended recipient(s)  which may be device(s) other than the first receiver on the transmission? (25 points)