# US 2008/0186994 A1 · Request detection error processing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0186994 A1 - Document ID: US20080186994A1 - Status: Published application - Kind: A1 - Application number: 11/771,903 - Filed: 2007-06-29 - Published: 2008-08-07 - Earliest claimed: 2007-02-06 - Assignees: ViaSat, Inc. - Inventors: Donald W. Becker - Web page: https://patentgrep.com/patent/US20080186994A1 ## CPC - H04B 7/18582: {Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access} - H04W 72/1273: of downlink data flows - H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network - H04W 84/06: Airborne or Satellite Networks (space-based or airborne stations H04B7/185) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Methods and apparatuses are presented for conducting communications over a shared communication medium, involving (a) sending a request from a first node, the shared communication medium organized to include (i) a request signal space including a plurality of request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) if no assignment is received from a second node in response to the request, retransmitting the request from the first node, and (c) if an assignment is received from the second node in response to the request, associating the request with a scheduled transmission segment selected from the plurality of scheduled transmission segments, sending a data transmission from the first node in the scheduled transmission segment associated with the request. ## Claims ### Claim 1 A method for conducting communications over a shared communication medium involving a plurality of nodes, the method comprising: (a) sending a request from a first node in the plurality of nodes, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request segments each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment that is one of the plurality of request segments; (b) if no assignment is received from a second node in response to the request, retransmitting the request from the first node; and (c) if an assignment is received from the second node in response to the request, wherein the assignment associates the request with a scheduled transmission segment selected from the plurality of scheduled transmission segments, sending a data transmission from the first node in the scheduled transmission segment associated with the request in accordance with the assignment. ### Claim 2 (depends on 1) The method of claim 1 wherein no assignment is received from the second node in response to the request, wherein the request is not detected by the second node. ### Claim 3 (depends on 1) The method of claim 1 wherein no assignment is received from the second node in response to the request, wherein the request is detected by the second node as being involved in a collision. ### Claim 4 (depends on 1) The method of claim 1 wherein the second node fails to detect a collision involving the request and sends the assignment to the first node. ### Claim 5 (depends on 4) The method of claim 4 wherein the first node sends a data transmission in response to the assignment from the second node. ### Claim 6 (depends on 5) The method of claim 5 wherein the data transmission is involved in a collision with another data transmission. ### Claim 7 (depends on 1) The method of claim 1 wherein receipt of the data transmission is not to be acknowledged by the second node, and if the second node does not properly receive the data transmission, the data transmission is not re-transmitted. ### Claim 8 (depends on 1) The method of claim 1 wherein receipt of the data transmission is to be acknowledged by the second node, and if the second node fails to send an acknowledgement of receipt of the data transmission, the first node sends a second request to request a second scheduled transmission segment for re-sending the data transmission. ### Claim 9 A method for conducting communications over a shared communication medium involving a plurality of nodes including a first node and a second node, the method comprising: (a) at the second node, receiving a re-transmitted request from the first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request segments each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the re-transmitted request sent in a request segment that is one of the plurality of request segments; (b) at the second node, making an assignment associating the re-transmitted request with a scheduled transmission segment selected from the plurality of scheduled transmission segments, the assignment taking into account location of the re-transmitted request within the request signal space, and sending a corresponding assignment message; and (c) at the second node, receiving a data transmission from the first node in the scheduled transmission segment associated with the re-transmitted request. ### Claim 10 An apparatus for conducting communications over a shared communication medium involving a plurality of nodes, comprising: (a) a first node capable of sending a request over the shared communication medium, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request segments each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the first node capable of sending the request in a request segment that is one of the plurality of request segments; (b) wherein if no assignment is received from a second node in response to the request, the first node is capable of re-transmitting the request; and (c) wherein if an assignment is received from the second node in response to the request, wherein the assignment associates the request with a scheduled transmission segment selected from the plurality of scheduled transmission segments, the first node is capable of sending a data transmission in the scheduled transmission segment associated with the request in accordance with the assignment. ### Claim 11 (depends on 10) The apparatus of claim 10 wherein if no assignment is received from the second node in response to the request, because the request is not detected by the second node, the first node is capable of re-transmitting the request. ### Claim 12 (depends on 10) The apparatus of claim 10 wherein if no assignment is received from the second node in response to the request, because the request is detected by the second node as being involved in a collision, the first node is capable of re-transmitting the request. ### Claim 13 (depends on 10) The apparatus of claim 10 wherein the first node is capable of receiving the assignment from the second node, wherein the second node fails to detect a collision involving the request and sends the assignment. ### Claim 14 (depends on 13) The apparatus of claim 13 wherein the first node is capable of sending the data transmission in response to the assignment from the second node. ### Claim 15 (depends on 14) The apparatus of claim 14 wherein the data transmission is involved in a collision with another data transmission. ### Claim 16 (depends on 10) The apparatus of claim 10 wherein receipt of the data transmission is not to be acknowledged by the second node, and if the second node does not properly receive the data transmission, the data transmission is not re-transmitted. ### Claim 17 (depends on 10) The apparatus of claim 10 wherein receipt of the data transmission is to be acknowledged by the second node, and if the second node fails to send an acknowledgement of receipt of the data transmission, the first node is capable of sending a second request to request a second scheduled transmission segment for re-sending the data transmission. ### Claim 18 An apparatus for conducting communications over a shared communication medium involving a plurality of nodes, comprising: (a) a second node capable of receiving a re-transmitted request from a first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request segments each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the second node capable of receiving the re-transmitted request in a request segment that is one of the plurality of request segments; (b) wherein the second node is capable of making an assignment associating the re-transmitted request with a scheduled transmission segment selected from the plurality of scheduled transmission segments, the assignment taking into account location of the re-transmitted request within the request signal space, and sending a corresponding assignment message; and (c) wherein the second node is capable of receiving a data transmission from the first node in the scheduled transmission segment associated with the re-transmitted request.