Patexia contests ask you to find, submit, and explain references that respond to our research criteria. If you are new, see patent and prior art basics and tips for Patexia's prior art contests, and refer to the submission notes below. The following questions will help you understand specifically what we are looking for in this study.

In this contest we are seeking prior art; published examples of an idea or invention before a specific date.

Problem Definition
Patexia seeks prior art for US Patents 5,809,428 (‘428) - “Method and device for processing undelivered data messages in a two-way wireless communications system” and  5,754,946 (‘946) - “Nationwide communication system.”

The ‘428 patent allegedly describes a network operations center (NOC) that transmits a data message to a mobile unit, awaits acknowledgement of receipt, and then sends a probe message to locate the mobile unit if no such receipt is received.

The ‘946 patent allegedly describes a two-way communication system between a network and a mobile unit, whereby the mobile unit receives messages from the network and transmits messages to the network. The mobile unit includes a switch that allows a user to request the network to retransmit a portion of a received data message that contains errors.

The basic system architecture of ‘428 has been illustrated below in Figure 1 and operates as follows:

• A network operations center (NOC) transmits and receives data messages to and from a wireless mobile unit.
• A data acknowledgement message is sent from the mobile unit to the NOC upon receipt of a data message.
• If the NOC does not receive a data acknowledgement message then a probe message is sent to the mobile unit.
• A probe acknowledgement message is sent from the mobile unit to the NOC upon receipt of a probe message.
• If the NOC does not receive a probe acknowledgement message then the data message is  stored and marked as undeliverable.
• ‘946 additionally allows a mobile user to request that a network retransmit a portion of a received data message that contains errors.

Figure 1. Method of Delivering a Data Message and Processing an Undeliverable Data Message

Questions
When entering a contest, Patexia’s system will ask you the following questions. Contestants should attempt to locate sources that answer these questions and submit a concise explanation as to why the source(s) answers our question(s). This explanation should specifically indicate where in the reference we can find the required supporting information. If you do not provide adequate explanations on how to locate the desired information in your reference, your entry will not be considered for a prize or in the final contest rankings.

Entries must answer all contest questions. All sources must be clearly dated or they will not be considered.

1. Was the source published before July 25th, 1996?
2. Does the source describe a two-way wireless communication system including a network and a mobile unit?
3. Does the source describe a mobile unit with the means to generate an acknowledgement message upon receipt of a data message by its transmitter?
4. Does the source describe a network transmitting a probe message to the mobile unit in the event that a data message has been sent and no acknowledgement message has been received?
5. Does the source describe a network with the means for storing and marking a data message as undeliverable in the event that a probe message has been sent and no acknowledgement message has been received?
6. Does the source describe a mobile unit with the means to power off only its transmitter?
7. Does the source describe a mobile unit with the means of determining whether or not it received a probe message while its transmitter was powered off?
8. Does the source describe a mobile unit with the means to transmit a registration message to a network in the event that it received a probe message while its transmitter was powered off?
9. Does the source describe a mobile unit with the means to receive an indication that a user desires to retransmit a portion of a received data message?
10. Does the source describe a mobile unit with the means to transmit, upon receipt of this indication, a signal requesting retransmission of the desired portion of the data message to the network?
11. Does the source describe a mobile unit with the means to receive and display the retransmitted portion of the data message?
12. [User Survey Question] Can you provide us with more information regarding your qualifications to enter this contest? (no reference needed, please provide a short list of your relevant background or qualifications.)
13. [User Survey Question] Can you provide us with more information regarding the time you spent researching the contests? (no reference needed, please provide an estimate of the time you spent researching this contest.)
14. [User Survey Question] Can you provide us with more information regarding the resources and databases you searched for this contest? (no reference needed, please provide a short list of sources that you used to research this contest.)