EP0186343A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transmitting sequence numbers of information in a packet data transmission system
Assignee: Nortel Networks Ltd
•
Filing: 1985-12-03
•
Granted: —
•
Expires: 2005-12-03
Abstract
Abstract In a packet data transmission system, correctly received information packets are acknowledged by piggybacking their sequence numbers onto information packets being transmitted. The control field of each information packet includes a bit which indicates whether or not there is a piggybacked acknowledgement. Acknowledgements can also be transmitted separately in control packets having no information field. Each acknowledgement consists of not only the sequence number of a correctly received information packet, but also the acknowledgement status of a plurality of preceding information packets whereby these can be negatively acknowledged if necessary. The sequence numbers can have any one of three different sizes, for efficient transmission of sequence numbers on transmission links of arbitrary transmission speed and length (and hence delay), The sequence number size which is used on any particular transmission link is determined on set-up of the link in dependence upon the transmission speed and the round-trip delay of the link.
Inventors
- 👤 David Scott Drynan
- 👤 David Maxwell Baker
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 10:47
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/12; H04L1/16; H04L1/18; H04L1/1809; H04L1/1607; H04L1/1628; H04L1/1642; H04L1/165; H04L1/1664; H04L1/1671
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
109 words
A method of transmitting sequence numbers of information packets in a packet data transmission system, each information packet comprising a control field and an information field, the control field of each information packet including a sequence number of the information packet, comprising the steps of selectively transmitting in said information packet the sequence number of an information packet received in an opposite direction of transmission thereby to acknowledge correct receipt of the received information packet, and transmitting in the control field of each information packet a bit whose state indicates the presence or absence in the information packet of the sequence number of a received information packet being acknowledged.
Claim 2
Independent Claim
109 words
A method of transmitting sequence numbers of information packets in a packet data transmission system, each information packet comprising a control field and an information field, the control field of each information packet including a sequence number of the information packet, comprising the steps of selectively transmitting in said information packet the sequence number of an information packet received in an opposite direction of transmission thereby to acknowledge correct receipt of the received information packet, and transmitting in the control field of each information packet a bit whose state indicates the presence or absence in the information packet of the sequence number of a received information packet being acknowledged.
Claim 3
Dependent Claim
46 words
A method as claimed in claim 1 and including the step of transmitting with each sequence number of a received information packet being acknowledged an acknowledgement status of each of n information packets received preceding said received information-packet being acknowledged, where n is a positive integer.
Claim 4
Independent Claim
108 words
A method of transmitting sequence numbers of information packets in a packet data transmission system, each information packet comprising a control field and an information field, the control field of each information packet including a sequence number of the information packet, comprising the steps of transmitting in the information packets sequence numbers of information packets received in an opposite direction of transmission thereby to acknowledge correct receipt of the received information packets, and transmitting with each sequence number of a received information packet being acknowledged an acknowledgement status of each of n information packets received preceding said received information packet being acknowledged, where n is a positive integer.
Claim 5
Independent Claim
108 words
A method of transmitting sequence numbers of information packets in a packet data transmission system, each information packet comprising a control field and an information field, the control field of each information packet including a sequence number of the information packet, comprising the steps of transmitting in the information packets sequence numbers of information packets received in an opposite direction of transmission thereby to acknowledge correct receipt of the received information packets, and transmitting with each sequence number of a received information packet being acknowledged an acknowledgement status of each of n information packets received preceding said received information packet being acknowledged, where n is a positive integer.
Claim 6
Dependent Claim
15 words
A method as claimed in claim 2 or 3 wherein n is greater than one.
Claim 7
Dependent Claim
11 words
A method as claimed in claim 4 wherein n= 3 .
Claim 8
Independent Claim
47 words
A method as claimed in any of claims 1 to 4 wherein each information packet which includes a sequence number of a received information packet being acknowledged includes, said sequence number at the end of the control field and before the information field of the information packet.
Claim 9
Independent Claim
54 words
A method as claimed in any of claims 1 to 6 wherein control packets each including a control field and no information field are also transmitted in said system, wherein the control field of each packet includes a bit whose state . indicates whether the packet is an information packet or a control packet.
Claim 10
Dependent Claim
39 words
A method as claimed in claim 7 wherein the control field of each control packet further includes a bit whose state indicates whether or not the control field includes the sequence number of a received information packet being acknowledged.
Claim 11
Dependent Claim
50 words
A method as claimed in claim 8 wherein the control field of at least some of the control packets includes at least one length bit whose state indicates which one of a plurality of different sizes of sequence numbers is used, all of the sequence numbers having the same size.
Claim 12
Dependent Claim
55 words
A method as claimed in claim 9 and including the step of determining the sequence number size by measuring the round-trip delay D for transmission of a packet via the packet data transmission system, and determining the sequence number size in dependence upon the measured delay D and the transmission speed T of the system.
Claim 13
Independent Claim
153 words
A method of transmitting sequence numbers of information packets in a packet data transmission system in which information packets and control packets are transmitted, each packet including a control field including a bit whose state indicates whether the packet is an information packet or a control packet, each information packet including an information field and including a sequence number of the information packet in its control field, the control field of at least some of the control packets including at least one length bit whose state indicates which one of a plurality of different sizes of sequence numbers is used, all of the sequence numbers having the same size, the method including the step of determining the sequence number size by measuring the round-trip delay D for transmission of a packet via the system and determining said size in dependence upon the measured delay D and the transmission speed T of the system.
Claim 14
Independent Claim
153 words
A method of transmitting sequence numbers of information packets in a packet data transmission system in which information packets and control packets are transmitted, each packet including a control field including a bit whose state indicates whether the packet is an information packet or a control packet, each information packet including an information field and including a sequence number of the information packet in its control field, the control field of at least some of the control packets including at least one length bit whose state indicates which one of a plurality of different sizes of sequence numbers is used, all of the sequence numbers having the same size, the method including the step of determining the sequence number size by measuring the round-trip delay D for transmission of a packet via the system and determining said size in dependence upon the measured delay D and the transmission speed T of the system.
Claim 15
Dependent Claim
61 words
A method as claimed in claim 10 or 11 wherein the round-trip delay D is measured by transmitting a first predetermined control packet, transmitting a second predetermined control packet in response to receipt of the first predetermined control packet, and timing the delay D from the transmission of the first predetermined control packet until receipt of the second predetermined control packet.
Claim 16
Independent Claim
29 words
A method as claimed in any of claims 9 to 12 wherein there are at least two length bits for representing at least three different sizes of sequence numbers.
Claim 17
Dependent Claim
19 words
A method as claimed in claim 13 wherein the control field of each control packet includes said length bits.
Claim 18
Dependent Claim
19 words
A method as claimed in claim 14 wherein the sequence number sizes differ from one another by 8 bit%,
Claim 19
Independent Claim
39 words
A method as claimed in any of claims 10 to 15 wherein the sequence number is determined to be the smallest of said plurality of different sizes which can hold a number T.D/B, where B is a predetermined integer.
Claim 20
Dependent Claim
15 words
A method as claimed in claim 16 wherein B is an integral power of 2.
Claim 21
Dependent Claim
9 words
A method as claimed in claim 17 wherein B=128.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.