Method of data transmission in a data communication network

• US 6,493,342 B1
• Filed: 09/11/1998
• Issued: 12/10/2002
• Est. Priority Date: 09/11/1998
• Status: Expired due to Term

• Current Assignee: Rateze Remote Mgmt. L.L.C. (Intellectual Ventures LLC)
• Original Assignee: Teledesic, LLC (Michael J. Larson, MBA)
• Inventors: Boyd, Nathan D. T., Breslow, Noah Joseph, Torluemke, Greg A.
• Primary Examiner(s): Yao, Kwang Bin
• Application Number:
  US09/151,994
• Time in Patent Office: 1,551 Days
• Field of Search: 370/316, 370/326, 370/345, 370/349, 370/394, 370/465, 370/470, 370/471, 370/473, 370/474, 370/493, 370/494, 370/495, 370/522, 370/523, 370/524, 370/527, 370/528, 370/529, 370/537, 370/538, 370/540
• US Class Current: 370/394
• CPC Class Codes: H04B 7/18584 Arrangements for data networking, i.e. for data packet routing, for congestion control data switching networks H04L12/00
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/824 Applicable to portable or mobile terminals
• CPC Class Codes: H04L 47/826 Involving periods of time

Abstract

A method of data transmission in a data communication network includes negotiating a connection between a source terminal and a destination terminal in the data communication network. During the connection negotiation process, optimal field lengths are determined for recording a source identifier and a sequence number in data packets transmitted in the connection. The source identifier identifies a connection from the source end to the destination end of the data transmission, while the sequence number identifies the relative position of a data packet in a series of data packets transmitted in the connection. The length of the source identifier and sequence number fields may either be calculated or selected from a set of predetermined field length values. Data packets formatted according to different transmission protocols (“secondary data packets”) that are received for transmission through the data communication network are packed into one or more “primary data packets” formatted according to the transmission protocol of the data communication network. In addition to a source identifier and sequence number, the primary data packets include a first packet offset to identify the location of a first new secondary data packet that is packed into the primary data packet. A first packet offset field length is determined during connection negotiation. The data transmission method of the invention includes packing one or more secondary data packets, or a portion thereof, in a primary data packet to fill the primary data packet, thus minimizing unused data bits in the primary data packet. After transmission, the primary data packets are reordered, if necessary, and the secondary data packets are unpacked therefrom.

Claims

1. A method of data transmission in a data communication network, comprising:

(a) generating a primary data packet formatted for transmission from a source terminal to a destination terminal in the data communication network, the primary data packet having a header and a payload, the header including a sequence number field and a first packet offset field, and the payload including one or more secondary data packets packed therein;

(b) recording a sequence number in the sequence number field, the sequence number identifying the relative position of the primary data packet in a series of primary data packets;

(c) recording a first packet offset value in the first packet offset field, the first packet offset value identifying the location of a first new secondary data packet that is packed in the primary data packet payload;

(d) transmitting the primary data packet from the source terminal to the destination terminal; and

(e) at the destination terminal, unpacking the one or more secondary data packets from the primary data packet payload, wherein the first new secondary data packet in the primary data packet payload is located for unpacking by reference to the first packet offset value.

2. The method of claim 1, wherein two or more primary data packets are transmitted through the data communication network, and wherein after the two or more primary data packets are received at the destination terminal, the two or more primary data packets are reordered according to their respective sequence numbers.

3. The method of claim 1, wherein the first new secondary data packet is located for unpacking by using the first packet offset value in an equation to produce a value identifying the location in the primary data packet payload.

4. The method of claim 1, wherein unpacking the one or more secondary data packets is performed even if the destination terminal has not yet received one or more prior primary data packets that were previously generated and transmitted by the source terminal.

5. A method of data transmission from a source ground terminal to a destination ground terminal in a LEO satellite data communication network, the method comprising:

(a) generating a primary data packet having a header and a payload;

(b) packing one or more secondary data packets in the payload of the primary data packet until the number of bits remaining available in the primary data packet payload is less than the number of bits in a secondary data packet not yet packed;

(c) dividing the secondary data packet not yet packed to define a first portion and a second portion, wherein the number of bits in the first portion equals the number of bits remaining available in the primary data packet payload;

(d) packing the first portion in the primary data packet payload;

(e) generating one or more additional primary data packets;

(f) packing the second portion in the payload of the one or more additional primary data packets, dividing the second portion as necessary into additional portions equaling the length of the payload of the one or more additional primary data packets; and

(g) transmitting the primary data packets from the source ground terminal to the destination ground terminal via one or more satellites in the LEO satellite data communication network.

6. The method of claim 5, further comprising:

(a) unpacking the one or more secondary data packets from the primary data packet payload; and

(b) if a portion of a secondary data packet was packed in the primary data packet payload, then unpacking the portion from the primary data packet payload.

7. The method of claim 6, further comprising retaining the unpacked portion of a secondary data packet in a memory with a timer, and deleting the unpacked portion from the memory when a period of time measured by the timer expires.

8. The method of claim 6, further comprising appending the unpacked portion of a secondary data packet to another previously unpacked portion of the same secondary data packet.

9. A method of data transmission in a data communication network, comprising:

(a) generating a primary data packet for transmission from a source terminal to a destination terminal in the data communication network, the primary data packet including one or more secondary data packets packed therein, the primary data packet further including a first packet offset field having a predetermined field length, the first packet offset field for recording a first packet offset value that identifies the location of a first new secondary data packet that is packed in the primary data packet;

(b) recording a first packet offset value in the first packet offset field, the length of the first packet offset value equaling the predetermined first packet offset field length;

(c) transmitting the primary data packet from the source terminal to the destination terminal; and

(d) at the destination terminal, unpacking the one or more secondary data packets from the primary data packet.

10. The method of claim 9, wherein the predetermined first packet offset field length is determined by the destination terminal during a connection negotiation conducted between the source terminal and the destination terminal prior to the generating and transmitting of the primary data packet.

11. The method of claim 10, wherein the primary data packet further includes one or more other data fields and the predetermined first packet offset field length is determined based on the length of the one or more other data fields.

12. The method of claim 11, wherein the one or more other data fields includes a source identifier field and a sequence number field.

13. The method of claim 9, wherein the one or more secondary data packets are packed at selected intervals in the primary data packet and the number of bits in the primary data packet between the selected intervals depends on the predetermined first packet offset field length.